LEAP Bridge Tutorials

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LEAP Bridge Enterprise Tutorials

DAA039160-1/0001

Bentley Systems, Inc. www.bentley.com

Tutorial 1

Tutorial 1

Two Span CIP prestressed box bridge with Multi-column Pier

LEAP® Bridge Enterprise v13.0.0 Tutorial One © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 1

Tutorial 1 Two-Span CIP Prestressed Box Bridge with Multi-Column Pier This tutorial is a step by step walkthrough of the analysis and design of a two-span cast-in-place posttensioned concrete box-girder bridge, with a multi-column pier using LEAP Bridge. The example illustrates the full lifecycle work flow starting with the basic modeling in the ABC Wizard, followed by detailed design using CONBOX, and ends with the detailed, step-by-step analysis and design of the reinforced concrete sub-structure using RC-PIER. While the design of abutments is also possible in RCPIER, for the sake of brevity, the detailed step by step design of the abutment is omitted for this example.

12 m 6m

6m 1.9625 m

4.0375 m

4.0375 m

1.9625 m

Z

2.5 m

Y

CG

1.8 m

Gross Properties CGz: 0.0000 m CGy: 1.0608 m Area: 7.7969 m^2 Izz: 7.4042 m^4 Vol/Area: 158.8126 mm

1.8 m

Superstructure Cross Section Sta 0+02

Figure W-1: Bridge superstructure cross-section view


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Tutorial 1 BB-EB CL: 44 m Span 1: 22 m

Span 2: 22 m

X Y

Figure W-2: Bridge side elevation showing span information

Figure W-3: Pier front and side views


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Tutorial 1

Bridge Data 1. Superstructure Concrete Properties fck, strength, at 28 days:

40 MPa

fi, initial:

35 Mpa

Weight:

2500 kg / m3

Single Stage Post-tensioning Strand Properties Strand Type:

27T13, LowLax

Ultimate Tensile Strength. fp:

1,860 MPa

Area:

2,667.6mm2

Duct diameter:

D=105.9 mm

Rebar Properties Flexure and Shear Steel:

Fe415, HYSD Steel

Dead Load on Superstructure: Self-weight of wearing surface, 2 crash barriers and 2 footpaths (left and right) Live Load IRC Loading, Maximum number of design lanes = 2 One lane of class 70R or two lanes of Class A

Substructure Concrete Properties (Cap, Column and Footings) fck, Strength, at 28 days: Weight:

35 MPa 2500 kg / m3


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Concrete Strength Cap Columns Footings Modulus of Elasticity Concrete Density Cap Columns Footings Steel Yield Strength Cap Columns Footings Modulus of Elasticity Superstructure Parameters Number of lanes Type (Pretensioned girders) Beam Height Beam Section Area Beam Inertia Ixx Beam Inertia Iyy Beam Ycg Kerb Height Slab Depth Total number of spans Span Information Bridge Overall Width, ft Curb to Curb Distance, ft Span Length, Span 1, ft

fck = 35 MPa fck = 35 MPa fck = 35 MPa Ec = 33,722 MPa 2500 kg/m3 2500 kg/m3 2500 kg/m3 fy = 415 MPa fy = 415 MPa fy = 415 MPa Es = 200,000 MPa =3 = 2500 mm = 7.79694e+006 mm2 = 7.79694e+006 mm4 = 7.79694e+006 mm4 = 1060.85 mm = 914.4 mm = 300 mm 2 12 m 12 m 22 m


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Tutorial 1

Start of Tutorial Start the LEAP Bridge software application by clicking on Start > All Programs > Bentley > LEAP Bridge. Set the Design Code to ‘India_IRC’ and fill in the general project information as shown in the figure below. The default units are preset to SI (Metric) units for the IRC code.

Figure W-4: Project tab information Click the Geometry tab, and start modeling the bridge using the ABC (automated bridge creator) Wizard. The Wizard can be launched simply by clicking on the ABC Wizard icon in the toolbar. Begin entering the information shown in Figure W-5 related to the bridge superstructure cross-section and span details. If detailed information about the geometry of the bridge including the alignment information, cross-section and vertical profile is available, this optional information can also be input at this stage. After completing the superstructure input, click on Next to move to step 2 and input information for the drop cap multi-column pier as shown in Figure W-6. The input is fairly straightforward and can be completed quickly by simply inputting the values for various input fields. If there are similar multiple piers, simply use the copy button to copy the current pier geometry to other piers.


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Tutorial 1

Figure W-5: ABC Wizard, Step 1, Superstructure details


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Tutorial 1

Figure W-6: ABC Wizard, Step 2, Substructure details (Pier) Once the input for the pier is complete, click on the Pier drop down in the top left hand corner of the window. Change the selection to “Abutment” and Number “1” and complete the input of abutment properties as shown in Figure W-7. Simply copy the Abutment Number 1 properties to the end abutment (Abutment Number 2) using the copy tool available on this screen.


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Tutorial 1

Figure W-7: ABC Wizard, Step 2, Substructure details (start abutment)

Next enter the values for the material properties as shown in figure W-8 below. These values will be used as defaults when data is transferred from LEAP Bridge to CONBOX or RC-PIER. After the initial model is built with these properties, the user will be able to override these default settings in the component programs. If all information for these three steps in ABC wizard is accurate, the status window will reflect the same, and you can press the finish button to complete the initial description and view the generated 3D model on the Geometry tab of LEAP Bridge as shown in Figure W-9.


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Now that the initial model has been created, you could play around with some of the viewing options such as rotation, zoom, and pan by either using the right mouse menu (context sensitive menu) or simply accessing the appropriate functions on the tool bar.

Figure W-8: ABC Wizard, Step 3, Materials.


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Tutorial 1

Figure W-9: 3D Bridge model in LEAP Bridge.

Now is a good time to save the input. Click on File/Save and provide a name “workshop1.xml” to save the file. Next, click on the Superstructure tab, and the click on the CONBOX button. All of the pertinent data is automatically transferred to CONBOX and CONBOX is displayed as shown in Figure W-10 below. Let us now complete the input process in CONBOX and complete the design of the superstructure.


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Figure W-10: CONBOX Project tab with information completed automatically. Since our demonstration model is quite simple, the definitions for Geometry in the ABC Wizard were quite sufficient and no further changes are required in the Geometry tab for Alignment, Pier, Layout and Cross-section. However we do wish to add the superimposed dead loads such as the crash barriers, footpath and wearing surface; so, simply click on the Geometry tab, and then click on the Crash Barriers button. Click on the Define buttons to view and change the dimensions. Make sure to hit the Include All button, and all of the dead loads are automatically considered in the appropriate load groups for analysis. Click OK to close this dialog and view the updated section view showing the 2D graphics for the barrier and footpath on the cross-section.

Figure W-11: Crash Barriers definition screen


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Tutorial 1 Figure W-12: Updated 2D graphics of bridge cross-section after adding crash barriers etc. Next click on the Model tab, and then the Tendon button and input the information for the three strands, one in each web, as shown in the screen below. Select the appropriate Tendon Type, i.e. 27T13.

Figure W-13: Tendon definition. Click OK to close this screen and move to the Loads and Analysis tab in CONBOX. By default all of the initial and final load cases, the appropriate loads and load factors all per IRC have already been predefined as shown in Figure W-14 and W-15. Note that some loads such as temperature gradient and construction will need to be manually deleted from this list of loads, to focus on workflow for this particular example; this can be done through the right-click menu options.


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Figure W-14: Load Combinations (for Initial) In the figure above, the right hand side tree with the BR01 (current box girder bridge) Loads are the library of loads on this particular bridge, and they can be edited here, and all instances of those particular loads are automatically updated wherever they are used. To use these loads simply drag and drop them over to the left hand pane in the appropriate Case (initial or final) and Combination. ( Service I, Ultimate I, etc.). The right-click menu option allows the user to automatically add a particular load defined on the right side to all load combinations on the left side; if a load is already present in any load combination, duplication is avoided.


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Figure W-15: Expanded view of BR01 Loads in Library.


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Figure W-16: Load Combinations (for Final) You can verify and if required edit and modify the load factors for each combination under both Initial and Final loads. Simply double-click on the Load Combination name in the left hand side window to bring up a dialog which looks similar to the screen shown in Figure W-17.

Figure W-17: IRC Load Combination Factors dialog, shown here for “Service I Final”. LEAP® Bridge Enterprise v13.0.0 Tutorial One © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Click on the Run Analysis button on the Loads/Analysis button to run the actual longitudinal analysis, moving the trucks along the bridge. Once the Analysis is complete, the Run Analysis button turns into View Analysis and you could look at the detailed reports (either as graphs or tabular data). Notice also that the program automatically switches you to the design tab, and shows the P-jack required vs. provided and also the initial and final concrete strengths required and provided as shown in Figure 18.

Figure 18: Results on the Design Tab

Figure W-19: Design Parameters dialog In the main menu click on Settings > Design Parameters to bring up the dialog showing the design parameters per IRC, as shown in Figure W-19. Notice that since we are working with PT concrete, some LEAP® Bridge Enterprise v13.0.0 Tutorial One © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 1

of the fields for Reinforced Concrete and Plain concrete are locked. Review the settings here, but since no changes are required, click cancel to close this screen and go back to the program. On the Design Tab, click on Rebar and in the Dialog which comes up, select Bar size MS25-GR1 and perform an auto-design. Program comes up with a rebar pattern as shown in Figure W-20. Click OK to accept and close the dialog.

Figure W-20: Auto-design in Longitudinal Rebar dialog. Next click on the Stirrups dialog and select MS12-GR1 for the stirrup size, 6 for number of legs and 150 mm for spacing and do an auto-design. Program comes up with a stirrup schedule which you could clean up to make it more construction friendly and click OK to accept the reinf. and also optionally copy this back to the model. You can view the results in CONBOX, by simply clicking on the Print icon in the toolbar to bring up the dialog shown below in Figure W-21


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Figure W-21: Auto design stirrups dialog.


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Figure W-21: Print dialog in CBX.

Now that the design of the superstructure is complete, Click OK to close CBX and transfer information back to the LEAP Bridge model for further processing of the substructure. Notice now that the reinforcement has been updated in the superstructure (visible when the transparency option is selected in the 3D view). See figure W-22 below.


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Figure W-22: Tendons, rebar and representative stirrups in the 3D bridge model in LEAP Bridge. Click on save the project. Next click on the SubStructure tab, select PR01 in Abut/Pier list and then click on the RC-PIER button, all of the pertinent data is automatically transferred to RC-PIER and it is displayed as shown in Figure W-23 below. Let us now complete the input process in RC-PIER and complete the analysis & design of the substructure.


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Tutorial 1

Substructure design

Figure W-23: RC-PIER Project tab with information completed automatically. Switch to Geometry tab and note that all the geometry information is filled in correctly. Click on Pier configuration. For this example, we will continue with multi column and round column as defined in ABC wizard in LEAP Bridge.


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Figure W-24: Pier configuration showing multicolumn, straight cap and round column You can review the superstructure parameters information as imported from CONBOX. Also, clicking on Cap, column, and footing dialog, you can review the respective geometry information. For this example, you need to define the bearing locations. Click on bearing dialog.


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Figure W25: Bearing data

Select single bearing line option. Define the 1st bearing at 2 m from the cap left end. Define 2nd bearing at 4 m from the previous bearing location. Click OK to accept these changes. The complete pier geometry can be reviewed in 3D view under geometry tab.

Figure W-26: 3D Graphical view of pier You can rotate; zoom in/out using the graphical options given below the 3D view. You can switch to 2D view to copy or print the pier geometry. Next, move to load tab to define the load applied on pier and select the desired load groups as per IRC specifications.


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Tutorial 1

For this example, primarily you will consider dead, live, wind, and braking force. Select dead load (G) from the list of loads available and click to select it. Select Dead load case (G) and click edit to open the load dialog. Click generate button to open the auto load generation options as shown in W-27 and select import load from superstructure option. Select the dead load G & SG to import the load on pier1, as shown in Figure W-28

Figure W-27: Auto dead load generation dialog.


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Figure W-28: Dead load imported from superstructure

Upon clicking “Generate” button will distribute the dead load on bearings as shown in Figure W-29.


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Figure W-29: Load case dialog Click OK to accept these values and close the dialog. In a similar way, select live load and select generate load. Keep the default IRC rule option and import the live load reactions for Class A and Class 70R vehicles from superstructure (CONBOX) as these are already computed during superstructure design as shown in Figure W-30. Depending on the carriageway width, program generates numerous live load combinations based on IRC 6-2000 specifications. Among these generated combinations, it isolates the most critical combinations producing the maximum effect in the individual members. On the same dialog, select the option to generate longitudinal forces. This will generate the breaking force for each combination.


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Tutorial 1

Figure W-30: Live load generation

Click OK to accept the load cases. Note that, program has generated 7 critical live load combinations. You can click on “LL details” to view the details of each live load positioning. Note: You can edit the individual load case to check the bearing reaction, but if you click OK after editing, program erases the live load details descriptions.


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Figure W-31: List of selected loads Now, select wind load case (Ws) and click edit to generate the wind load forces on structures. Generate the wind load for a range of wind angles from 30 degrees to -30 degrees. You can generate the wind load force acting independently or simultaneously acting on the live load. For this example, we will generate the wind acting simultaneously on the live load by checking the appropriate box. Depending on the bridge location and pier elevation, correct wind pressure per IRC, acting on substructure, will be selected.


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Figure W-32: Wind load generation dialog Once all the required load cases are defined, select Service I and Service IIIA load groups. Next, move to Analysis tab. Click on A/D Parameters (Analysis and Design Parameters) to check the permissible stress values. For this example, we will not make any changes and use the default parameters. Run the analysis and program will generate the default load combinations. You can review the analysis results for each load case or for particular combination at each specific member node


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Figure W-33: Analysis results dialog Now, you are ready to design the individual components cap, column and footing based on IRC specifications. Switch to Cap tab and select Auto-design. This prompts the user to select the rebar size. Select MS25- GRI and MS-12-GR1 for stirrup size. Program comes with its own reinforcement and stirrup schedule, which can be edited manually. Click on Design status to review the flexure, shear and torsion design. If at any locations, design fails, program flags that location.


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Figure W-34: Cap design tab

Similarly, design the columns & footings. Start with auto-design and based on the stress check results, you can revise the reinforcement pattern. For column design, as shown in figure W33, auto-design will prompt you select one or multiple rebar choices. Program will select the rebar which satisfies the stress check or axial capacity if column is only axially loaded. For this example, select MS-25 Gr1 along with MS8-Gr1 for stirrups. If section is getting cracked, revise the cross section.


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Figure W-35: Column design reinforcement

In the footing design, you can use either use Auto-design or manually define the reinforcement. Depending on the footing type, this dialog will be slightly different. For combined footing, user can define the reinforcement start and end locations. For this example, we have defined spread footings and will use Auto-design. You can design all footings at the same time by checking the box for “Auto-design all “. Select FTG01 from the available list and click Auto-design. Use MS25-GR1.


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Figure W-36: Footing design tab You can view the results in RC-PIER by simply clicking on the Print icon in the toolbar to bring up the dialog shown below in Figure W-37.


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Figure W-37: Print dialog in RC-PIER. Now that the substructure design is complete, Click OK to close RC-PIER and transfer information back to the LEAP Bridge model. Notice that the reinforcement has been updated in the substructure (visible when the transparency option is selected in the 3D view). See figure W-38 below.


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Tutorial 1

Figure W-38: Pier reinforcement display in 3D model of LEAP Bridge.

Save the project to continue the design of abutment.


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Tutorial 2

Tutorial 2

Two span bridge with pre-tensioned concrete girders, and multi-column pier.

Tutorial 2

Tutorial 2 Two span bridge with pre-tensioned concrete girders, and multi-column pier. This tutorial takes you through the modeling, analysis and design of a two-span bridge with precast pretensioned girder superstructure and multi column pier substructure.

240 mm

12.1 m

1.55 m

3m

3m

1

2

3m 3

1.55 m 4

Figure T2-1: Bridge Superstructure Cross-section view

Figure T2-2: Span Data

Figure T2-3: 1200 mm Girder details & properties

Area

5.44x105 mm2

Ycg (from bottom)

562.86 mm

Moment of Inertia

1.05843 x 1011 mm4

Height

1200 mm

Web Thickness

200 mm

LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 2

Figure T2-4: Longitudinal Pier Elevation view

Figure T2-5: Transverse Pier Elevation


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Tutorial 2


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Figure T2-6: Footing Plan and Elevation

Problem Data Concrete Properties Strength, precast at release/transfer:

35 MPa

Strength, precast at 28 days:

40 MPa

Strength, cast-in-place topping (Deck slab):

40 MPa


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Tutorial 2

2500 kg / m3

Weight:

Strand Properties Strand Type: High Tensile steel, Low relaxation, 7 wire strand, 12.7mm dia, UTS = 1860 MPa Straight Strand Pattern Rebar Properties Fe415, HYSD Steel. Live Load IRC Loading Class A and Class 70R, maximum number of design lanes = 3, Carriageway width = 11.1 m Dead Load Weight of each barrier 6 KN/m. Total weight of left and right barriers: 12 KN/m Substructure Data:

Concrete Strength Cap

fck = 35 MPa

Columns

fck = 35 MPa

Footings

fck = 35 MPa

Modulus of Elasticity

Ec = 33722 MPa

Concrete Density Cap

2500 kg/m3

Columns

2500 kg/m3

Footings

2500 kg/m3

Steel Yield Strength Cap

fy = 415 MPa

Columns

fy = 415 MPa


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Tutorial 2 Footings

fy = 415 MPa

Modulus of Elasticity

Es = 200,000 MPa

Superstructure Parameters Max. No. of Design Number of lanes

=3

Type (Pretensioned girders) Beam Height

= 1200 mm

Beam Section Area

= 54399 mm2

Beam Inertia Ixx

= 1.058e+011 mm4

Beam Inertia Iyy

= 1.058e+011mm4

Beam Ycg

=562.8 mm

Curb Height

= 914.4 mm

Slab Depth

= 240 mm

Total number of spans

2

Span Information Bridge Overall Width, ft

12.1 m

Curb to Curb Distance, ft

11.1 m

Span Length, Span 1, ft

17.545 m

Substructure Load Dead load Self weight

2500 kg/m3

Slab

2500 kg/m3

Girder weight

2500 kg/m3

Curb Weight

= 12 KN/m

Future Wearing surface

= 6.100 KN/m


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Tutorial 2 Live Load

Class 70R, Class A

70R and Class A reaction from Superstructure

Wind on structure Direction of Wind

30 to -30

Elevation above which wind acts

=0m

Trans. Wind pressure on superstructure

463.7 Pa

Long. Wind pressure on superstructure

115.92 Pa

Wind on Live load Length of live load

18.22 m


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Tutorial 2

Start of Tutorial Start the LEAP Bridge software application by clicking on Start > All Programs > Bentley > LEAP Bridge. Set the Design Code to ‘India_IRC’ and fill in the project information as shown in the figure below.

Figure T2-7: Project Tab Click on the Geometry tab, and start the modeling of the bridge using the ABC (automated bridge creator) Wizard. The Wizard can be launched simply by clicking on the ABC Wizard icon in the toolbar. Begin Entering the information shown in Figure T2-8 to enter bridge superstructure cross-section and span details.


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Figure T2-8: Step 1 ABC Wizard – Superstructure input


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Figure T2-9: ABC Wizard – Step 1 – Span Details input Note: To add a new section to the beam section library, Start LB, go to the superstructure tab and click on CONSPAN. Within CONSPAN, go to the Libraries menu and click on Beam Sections. Select the I-girder type and click on Add. Enter the properties including the strand template, save changes to library and close CONSPAN and come back to LEAP Bridge.


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Tutorial 2

Figure T2-10: ABC Wizard – Step 2: Pier Definition


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Tutorial 2

Figure T2-11: ABC Wizard- Step 3: Materials Data Click Finish and the 3D model is generated and can be seen in the Geometry Tab.


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Tutorial 2

Figure T2-12: Geometry Tab showing 3D Model.


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Tutorial 2

SUPERSTRUCTURE DESIGN Now that the basic bridge model has been built, let us analyze and design the superstructure in detail by moving to the superstructure tab and then click on the CONSPAN button. Note CONSPAN is the component software for the design of pre-tensioned girders while CONBOX is for the design of Box Girders, Slabs and T-beam bridges.

Figure T2-13: Superstructure Tab showing 2D view When CONSPAN comes up, you will notice that all of the Project and Geometry information is already filled in, as was described in the ABC Wizard input. So simply verify the information and move to the Materials tab, and set up the information as shown in the figure below.


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Figure T2-14: Material Tab Next click on the loads tab to specify dead and live loads. For dead loads we will use the dead load wizard dialog shown below to specify the left and right curb weight values and a future wearing surface value. Make sure to set the keep Values option checked so that these values are retained in this dialog.

Figure T2-15: CONSPAN: Dead Load Wizard Tab LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 2

For Live Loads, let us stay with the default load selection as per IRC rules. Modify the parameters c,f & g as shown below. CONSPAN will automatically apply the appropriate loads in the appropriate lanes and combinations and determine the governing/controlling loads. While the initial longitudinal analysis is done by loading a continuous beam model influence lines, the transverse distribution is done by using the Courbon’s method.

Figure T2-16: Loads Tab showing both Dead and Live Loads. Next click on the Analysis Tab. You can see that there are no results since the analysis has not yet been done. You can view the factors which are set up as per the recommendations in the IRC codes. We will not make any changes here for either dead or live load distribution.


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Figure T2-17: Analysis Tab / Analysis Factors. Now click on the Run Analysis button and all the dead and live loads are processed and the results are displayed as shown below. Results can be seen for specific loads, various combinations for Service or Strength/Ultimate, for each span and for each beam.


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Tutorial 2

Figure T2-18: Analysis Tab / Analysis results. You can view the Project Design Parameters by clicking on the design parameters button and verify the settings for the design of the pre-tensioned beams. In this screen you can set various design parameters such as permissible stresses, moment and shear design criteria etc.


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Tutorial 2

Figure T2-18: Beam Tab After the analysis is completed, click on the beam tab to specify the prestressing strand pattern. You can select the specific beam that you want to design the strand pattern for by simply clicking on the beam in the top window or using the drop down box and selecting the span # and the beam #. Double-click the beam icon or click on Strand Pattern button to bring up the Strand Pattern screen. In the Strand Pattern dialog, enter the strand pattern shown in the screen below which includes a mix of straight and draped strands. You can check the design status for this group of strands and verify that all release stresses, service stresses and ultimate moment requirements are satisfied. Any overstress or undercapacity is highlighted in the reports to draw the user’s attention. For this example, select beam 2 and define the strand pattern as shown in Figure T2-19.


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Tutorial 2

Figure T2-19: Beam Tab The design status reports only provide partial reports. After you click OK on the Strand Pattern screen and accept the strand pattern, you can view more comprehensive results by clicking on the Results button. In the dialog that is shown below, you can specify exactly which section of the report you would like to see/print etc.


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Figure T2-20: Results Dialog Close CONSPAN by clicking on File / Exit, then click OK on the message which prompts you to update the LEAP Bridge Model. By doing this all the reinforcement is now written back to the LEAP Bridge Model as also reactions for use in the substructure design. Click no to generate reports at this time. If the transparent mode is turned on the Geometry tab 3D image, the strands can be seen in the beams.


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Tutorial 2

Substructure Design

Click on the Substructure tab and then on the RC-PIER button. When RC-PIER comes up, you will notice that all of the Project and Geometry information is already filled in, as was described in the ABC Wizard input. So simply verify the information and move to the Loads tab, and set up the information as shown in the figure below. Step 1 The Project screen will be displayed, as shown in Figure T2-21.By default IRC standard and SI unit will be selected. Complete the other project information.

Figure T2-21: Project Information Screen Step 2 Click on the Geometry tab to open the Geometry screen, as shown in Figure T2-22. Click and drag to rotate the model. LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Figure T2-22: Geometry Tab Screen Step 3 Click on Pier Configuration to open the Pier Configuration screen, as shown in Figure T2-12 Note that, Multi Column Pier Type, , Straight Cap Shape, and Round Column Shape are selected. Set the Pier View direction to Upstation. Click OK.


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Tutorial 2

Figure T2-23: Pier Configuration Screen Step 4 Click on Superstructure to open the Superstructure Parameters screen. All the values for the number of lanes, beam height and area, curb/railing height, slab depth, total number of spans, and total length and width of spans, are brought over from the superstructure program as shown in Figure T2-24. . Also, bridge type selected is pretensioned girders based on the superstructure specified in LEAP Bridge. Upon review, click OK to accept and close superstructure parameter dialog.


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Figure T2-24 Superstructure Parameters Screen

Step 5 Click on Cap to open the Straight Cap Parameters screen, as shown in Figure T2-14. Verify the various dimensions shown such as pier cap (12.1 m), Cap Height (1500 mm), Cap Depth (2700 mm), and the Start and End Elevations (28.9151 m, each). Click OK.


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Tutorial 2

Fig T2-14: Cap properties Screen Step 6 Click Column to open the Rounded Column screen, as shown in Figure T2-15. (This screen will be specific to the type of column shape selected.) For this tutorial, we are using three columns, as follows.

Figure T2-15 Round Column Screen To modify a column, highlight it in the list, make the necessary changes, and click Modify. To delete a column, highlight it and click Delete. Step 7 LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 2

Click on the Footing|Pile button to open the footing configuration. Notice three footings have been defined. The following illustrates how to define a spread footing and pile/cap footing.

Figure T2-16 Footing input Screen 1. Select FTG03 and click on Edit to activate the Isolated Spread Footing screen, as shown in Figure T2-17


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Tutorial 2

Figure T2-17 Isolated Spread Footing Screen How to define the Pile/Cap Footing Design, as follows: 2. Select [email protected] under Columns, input Pile cap in the Name field, and select Pile/Shaft Cap under Type. Click Add. The name Pile cap will appear in the list at the bottom of the screen.


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Tutorial 2

Figure T2-18 Footing: Isolated Pile/Shaft Cap Design Screen 3. Select user input and specify footing size of 3.6 m × 3.6 m. Choose concentric under column. 4. Under Pile/Shaft configuration, select Circular from the Pile/Shaft Shape list and input 12 in the Pile/Shaft Size field and 150 in the Max. Pile Capacity field. 5. In the Edit Mode, select From Library, to use the pile pattern defined in the library screen. 6. Click OK and return to the Footing screen. Step 8 In this example, we will design the isolated spread footing under column 1 which also works for the footings under column 2 & 3. On the Footing tab, select column 2 in the columns list. Specify the footing name as Spread2 and click Add, On the Isolated Spread Footing dialog click on the Copy From button Select FTG01 from in the list and click Copy. All information about FTG01 will be copied to FTG02 and FTG03 footing.

Step 9 Click on Brgs/Grdrs to open the Bearings/Girders screen, as shown in Figure T2-19. This screen is used to define the configuration of the bearing line - eccentricity, and distance from left end of pier cap to individual bearings. Note that, all the bearing information should have already been automatically filledin as defined in superstructure. LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 2

Figure T2-19: Bearing input screen. Double Configuration indicates that there are two bearing lines on the pier. For each bearing point, the distance is defined either using Cap Left End option under Distance From or with respect to the last point. To modify a bearing line in the list, highlight it, make the appropriate changes, and click Modify. To delete a bearing line, highlight it and click Delete. Note: If you want to redefine the bearing location, the first bearing point must be measured from Cap Left End. For all other points, you can select the Last Point option. This allows you to input the same value multiple times; each new bearing spaced evenly from the previous bearing. Step 10 Click Material to activate the Materials screen, as shown in Figure T2-20. This screen defines the strength, density, concrete modulus of elasticity, and reinforcing steel strength as well as the concrete type. Notice that the program defaults to certain values. You can override these values by typing over them. Input the values shown in the figure and click OK to return to the Geometry screen.


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Figure T2-20 Materials Screen Step 11 Click Str. Model to open the Structure Model screen, as shown in Figure T2-21. Use this screen to keep track of all nodes of the pier structure, add or remove nodes of the pier structure for use as reference points (checkpoints), and define hinges at existing points. Click Cancel to return to the Geometry screen.


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Figure T2-21 Structure Model Screen LEAP® RC-PIERv9.0.0 T1 -13 Step 12 Select Image from the Show menu to activate the Image screen (or the corresponding icon on the toolbar at the top of the screen). A 3-D image of the structure will be displayed on the screen, as shown in Figure T2-22.


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Figure T2-22 Image Screen Use the buttons on the left of the screen to manipulate your view of the image (e.g., rotate, pan, zoomin or out). Experiment with the buttons to become familiar with their functions. Close or minimize the screen and return to the Geometry screen. Step 13 Select Model from the Show menu or its corresponding icon on the toolbar at the top of the screen to bring up the Model screen as shown in Figure T2-23. A 3-D model of the nodes, element number, etc will be displayed on the screen.


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The type of model displayed depends on which characteristics you select from the check boxes at the top of the screen (Node Number, Member Number, and Checkpoints). Use the buttons on the left side of the screen to manipulate your view of the model (e.g., rotate, pan, zoom-in or out). Experiment with these buttons to become familiar with their functions. Close or minimize the screen and return to the Geometry screen.

Step 14 Click the Loads tab to display the Loads screen, as shown in Figure T2-24. This is where you enter all load information.


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Tutorial 2

Figure T2-24 Loads Tab Screen Notice there are two lists of loads: Load Types and Available Groups. Load Types are preset individual loads that you can add to the pier structure for calculations. Available groups are preset load combinations that can be added to the pier structure. First, add the load types (shown in Figure T2-24) to the Selected Load list: 1. Highlight G - Dead Load in the list under Load Type. 2. Click the right-arrow button. The load type will appear in the list under Selected Loads. 3. Repeat the above steps until all the required loads have been entered, as shown in Figure T1-16. Next, add the load groups to the Selected Groups list: 4. Highlight Service Group I in the list under Available Groups. 5.

Click the right-arrow button. The load group will appear in the list under Selected Groups. 6. Repeat the above steps until all required load groups are entered, as shown in Figure T2-24 Remove a selected group from the Selected Groups list by clicking the left-arrow button (<-). To remove all groups from the Selected Groups list, click the <== button. To define groups, select the Load Groups/Limit States item from the Libraries menu.

Step 15 LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 2

Auto-generate loads for dead load, live load, wind load on structure, and wind load on live load. 1. Highlight G1 in the Selected Loads list and click Edit. The Loads: Load Data screen will display, as shown in Figure T2-25

Figure T2-25 Loads: Load Data Screen 2. Click Generate to bring up the Auto Load Generation: Structure G screen, as shown in Figure T2-26. (Note that the auto load generation screen will be specific to the load type selected).


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Figure T2-26: Autoload generation of dead load screen 3. You can use select import load from superstructure. If you wish to generate the load instead of importing load, select the check boxes to include slab and girders and select the option “use simple span distribution for barrier and wearing surface. 4. Click Generate. The program will automatically generate the loads and return to the Loads: Load Data screen as shown in Fig T2-27. Click OK to return to the Loads screen.


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Step 16 Auto generate live load: 1. 2.

Highlight (Q+Qim)1 in the Selected Loads list and click Edit to bring up the Loads: Load Data screen. Click Generate to activate the Auto Load Generation: Live Load screen, as shown in Figure T227


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Figure T2-27 Auto Load Generation: Live Load Screen - Prior to Auto Generation 3. In the longitudinal reaction area, select the option “Import Superstructure Reaction” and define max truck load as 986.238 kN for braking force calculation 4. Instead of importing live load from superstructure, you can select IRC vehicles and generate live load reaction within RC-PIER as well. 5. If you select IRC rule, program will automatically select the vehicles and number of lanes based on bridge width. 6. Click Generate. The program will automatically generate the loads and return to the Live load screen as shown in T2-28.


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7. If desired, input a name in the Name text box (e.g., llcase1) and a description in the Description text box.

Figure T2-28 Auto Load Generation: Live Load Screen - Post to Auto Generation 8. Click OK and return to the Loads screen. Note that when you return to the Loads screen after generating the live loads, RC-PIER adds (Q+Qim)2, (Q+Qim)3, (Q+Qim)4, .. (Q+Qim)38, load cases to the list under Selected Loads. The Loads screen will look similar to Figure T2-29


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Tutorial 2 Step 17

1. Highlight W1 in the Selected Loads list and click Edit to bring up the Loads: Load Data screen. 2. Click Generate to open the Auto Load Generation: Wind on Structure screen, as shown in Fig T230

Fig T2-30 Auto Load Generation: Wind on Structure Screen 3. Select multiple angle check box and 30 & -30 from Start and End Wind Angle list. 4. Enter 0 in the Elevation above Which Wind Load Acting field. 5. Select Plain terrain as bridge location. Use the Default Wind Pressure check box. (Note that when this option is selected, the remaining fields are grayed out.) 6. Click Generate. The program automatically generates the loads and returns to the Loads: Load Data screen. 7. Click OK and return to the Loads screen. Step 18 Auto-generate the Wind Load on Live Load: 1. Highlight WL1 in the Selected Loads list and click Edit to bring up the Loads: Load Data screen. 2. Click Generate to open the Auto Load Generation: Wind on Live Load screen, as shown in Figure T2-31


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Figure T2-31 Auto Load Generation: Wind on Live Load Screen 3. Select 30 & -30 from the Wind Angle list and leave 17.545 m in the Length of Live Load field. 4. 4.Click Generate. The program automatically generates the loads. 5. 5.Click OK and return to the Loads screen. Step 19 Click the Analysis tab to activate the Analysis screen. This screen is used to perform an analysis and also specify various factors relating to the analysis and design. Click A/D Parameters to open the Analysis/Design Parameters screen and input the values for permissible stresses as shown in Figure T2-32. Click OK and return to the Analysis screen.


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Figure T2-32 Analysis/Design Parameters Screen Click Run Analysis to perform the analysis for the pier structure based on all the data entered up to this point. The results will appear on the screen, as shown in Figure T1-25. If necessary, use the scroll bar on the right side of the screen to view all the results. Specify the type of results to view by using the lists at the top of the screen.


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Figure T2-33 Analysis Tab Screen (After Analysis is Performed) Print the analysis results by right-clicking in the results area of the Analysis screen and selecting the Print. Step 20 Click the Cap tab to open the Cap screen, as shown in Figure T2-34 Use this screen to have RC-PIER design the cap. Clicking Auto Design or you can manually input the cap design. The following steps illustrate the auto design feature.


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1. Select Cap from the Selection list. 2. For this example, we will define the reinforcement manually instead of using autodesign. Define top and bottom reinforcement using MS32-GR1 as shown below in Figure T2-35.


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Figure T2-35 Design Cap Screen 3. Select MS12- GR1 from the Stirrup Size list, 4 from the nlegs list and specify 120 mm in the spacing increment box. 4. Click OK. 5. Click Design Status - Cap screen to review the flexure, shear and torsion design. Click Close (or the X in the top right corner of the screen) to exit this screen and return to the Cap screen. 6. Review the cap design and modify the reinforcement/stirrup definition. 7. To see a design summary of the cap, click Design Status to display the cap summary, as shown in Figure T2-36. Click Print to print the design summary.


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Figure T2-36 Design Status - Cap Screen (In Enhanced Report Format) To see a graphical representation of the cap, click Sketch. Note:The printout for shear/torsion design is given in terms of the sides of a section. For the section other than the start or end of a span, it has two sides: left and right. The start and end of the span have only one side. Step 21 Click the Column tab to open the Column screen, as shown in Figure T2-37 Either manually input the column reinforcement or have the program automatically design it. For this tutorial, the Auto Design feature is used.


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Figure T2-37 Column Tab Screen 1. Select 1 from the Column# list and Ties from the Lateral Bar Type list. 2. Click Auto Design to bring up the Design Column screen, as shown in Figure T2-38.

Figure T2-38 Design Column Screen LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 2

3. Select MS 32-GRI from the Bar Size list and MS6-GR1 from the Stirrup Size list. 4. Click OK. 5. The Design Status - Column screen will be displayed. Click Close or the X in the top right corner of the screen to exit this screen and return to the Column screen.

To see a design summary of the selected component, click Design Status on the Column screen to activate the Design Status - Column screen, as shown in Figure T2-39. Click Print to print the design summary or click Sketch to see a graphical representation of the selected column. Step 22 1. Select the desired footing from the footing list. The footing tab screen shows as follows:


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Tutorial 2

Figure T2-40 FootingTab Screen

2. Similar to cap and column, user can click Autodesign or manually define reinforcement. 3. Click on Autodesign and select the MS-28 rebar size from the list. Define hook at 90 degrees on both sides.

Figure T2-41 Autodesign footing screen 4. The Design Status - Footing screen will immediately display. Click Close or the X in the top right corner of the screen to exit this screen and return to the footing screen.


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Figure T2-42 Footing design status screen

Step 23 LEAP® Bridge Enterprise v13.0.0 Tutorial Two © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 2

Select Diagrams from the Show menu to activate the Diagram screen, as shown in Figure T2-42 Experiment with the lists and buttons to become familiar with the options of this feature. Step 24 To print the output of the project, select Print from the File menu and the Print screen will display. Select the appropriate options and click OK.

Figure T2-43 Footing design status screen This completes Tutorial 2.


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Tutorial 4

Tutorial 3

Single Span Slab Bridge with Abutment.

Tutorial 3

Tutorial 3

Single span slab bridge with abutment This tutorial is a step by step walkthrough of the analysis and design of a single span cast-in-place concrete slab bridge, and an abutment using LEAP Bridge. The example illustrates the full life cycle work flow starting with the basic modeling in ABC Wizard, and then on to detailed design using the box bridge analysis and design software CONBOX, followed by detailed step by step design and analysis of the reinforced concrete sub-structure using RC-PIER.



LEAP® Bridge Enterprise v13.0.0 Tutorial Three © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 3

Figure W-3: Abutment views

Bridge Data 2. Superstructure Concrete Properties fck, strength, at 28 days:

35 MPa

fci, initial

25 Mpa

Weight:

2500 kg / m3


Fe415, HYSD Steel.

Dead Load on Superstructure: Self-weight of wearing surface, two crash barriers, and two footpaths (left and right) Live Load IRC Loading: Carriageway width = 7.5 m, Maximum number of design lanes = 2, One lane of class 70R or two lanes of Class A,. . Substructure Concrete Properties (Cap, Column and Footings) Strength, at 28 days:

35 MPa

Weight:

2500 kg / m3


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Tutorial 3

Concrete Strength Stem wall Footings Modulus of Elasticity Concrete Density Stem wall Footings Steel Yield Strength Stem wall Footings Modulus of Elasticity Superstructure Parameters Number of lanes Type (Reinforced Concrete Slab) Slab Height Slab Section Area Slab Inertia Ixx Slab Inertia Iyy Slab Ycg Curb Height Total number of spans Span Information Bridge Overall Width, ft Curb to Curb Distance, ft Span Length, Span 1, ft

fck = 35 MPa fck = 35 MPa Ec = 33722 MPa 2500 kg/m^3 2500 kg/m^3 fy = 415 MPa fy = 415 MPa Es = 200,000 MPa =3 = 850 mm = mm2 = 1.02e+007 mm4 = 4125+011 mm4 = 425 mm = 914.4 mm 1 12 m 12 m 12.625 m


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Tutorial 3

Start of Tutorial Start the LEAP Bridge software application by clicking on Start > All Programs > Bentley > LEAP Bridge. Set the Design Code to ‘India_IRC’ and fill the project information as shown in the figure below. The units are preset to SI (Metric) units for the IRC code.

Figure W-4: Project tab information Click the Geometry tab, and start the modeling of the bridge using the ABC (automated bridge creator) Wizard. The Wizard can be launched simply by clicking on the ABC Wizard icon in the toolbar. Begin entering the information shown in Figure W-5 to enter bridge superstructure cross-section and span details. If detailed information about the geometry of the bridge including the alignment information, cross-section and vertical profile is available, the optional information can also be input at this stage. After completing the superstructure input, click on Next to move to step 2 and input information for the stem wall abutment as shown in Figure W-6 shown below. The input is fairly straightforward and can be completed quickly by simply inputting the values for various input fields. If the information for end abutment is same, simply use the copy button to copy the current abutment information to end abutment.


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Figure W-6: ABC Wizard, Step 2, Substructure details (Start Abutment) Once the input for the abutment is complete, click on the Pier drop down in the top left hand corner of the window. Simply copy the abutment properties to the end abutment (Number 2) using the copy tool available on this screen. Next enter the values for the material properties as shown in figure W-8 below. These values will be used as defaults when data is transferred from LEAP Bridge to CONBOX or RC-PIER. Once the initial model is built with these properties, the user will be able to override these default settings in the component programs. If all information for these three steps in ABC wizard is accurate, the status window will reflect the same, and you can press the finish button to complete the initial description and view the generated 3D model in the Geometry tab of LEAP Bridge as shown in Figure W-9. LEAP® Bridge Enterprise v13.0.0 Tutorial Three © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Now that the initial model has been created, you could play around with some of the options available for rotation, zoom, pan operations by either using the right mouse menu (context sensitive menus) or simply accessing the appropriate functions on the tool bar.



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Now is a good time to save the input. Click on File/Save and provide a name “Tutorial 3.xml” to save the file. Next click on the SuperStructure tab, and the click on the CONBOX button, all of the pertinent data is automatically transferred to CONBOX and CONBOX is displayed as shown in Figure W-10 below. Let us now complete the input process in CONBOX and complete the design of the superstructure.


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Figure W-10: CONBOX Project tab with information completed automatically. Since our demonstration model is quite simple, the definitions for Geometry in ABC Wizard were quite sufficient and no further changes are required in the Geometry tab for Alignment, Pier, Layout and Cross-section. However we do wish to add the superimposed dead loads such as the crash barriers, footpath and wearing surface, so simply click on the Geometry tab, and then click on the Crash Barriers button. Make sure to hit the Include All button, and all of the dead loads are automatically considered in the appropriate load groups for analysis. Click OK to close this dialog and view the updated section view showing the 2D graphics for the barrier and footpath on the cross-section.


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Figure W-11: Crash Barriers definition screen LEAP® Bridge Enterprise v13.0.0 Tutorial Three © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Figure W-12: Updated 2D graphics of bridge cross-section after adding crash barriers etc. Now, since we don’t have PT tendons in this slab, move to the loads and analysis tab in CONBOX. By default all of the initial and final load cases, the appropriate loads and factors all per IRC have already been predefined as shown in Figure W-14 and W-15. Note that some loads such as temperature gradient and construction will need to be manually deleted from this list of loads, to focus on workflow for this particular example.


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Figure W-14: Load Combinations (for Initial) In the figure above, the right hand side tree with the BR01 (current box girder bridge) Loads are the library of loads on this particular bridge, and they can be edited here, and all instances of those particular loads are automatically updated wherever they are used. To use these loads simply drag and drop them over to the left hand pane in the appropriate Case (initial or final) and Combination. ( Service I, Ultimate I, etc.) or use the option in the right-click menu to automatically add the load to all load combinations.


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Figure W-15: Expanded view of BR01 Loads in Library.


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Figure W-16: Load Combinations (for Final) You can verify and if required edit and modify the load factors for each combination under both initial and final loads. Simply double click on the Load combination name in the left hand side window to bring up a dialog which looks similar to the screen shown in Figure W-17.


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Figure W-17: IRC Load Combination Factors dialog, shown here for “Service I Final”. Click on the Run Analysis button on the Loads/Analysis button to run the actual longitudinal analysis, moving the trucks along the bridge and then performing an automatic transverse distribution of loads using the Courbon’s method. Once the Analysis is complete, the Run Analysis button turns into View Analysis and you could look at the detailed reports (either as graphs or tabular data).


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Figure W-19: Design Parameters dialog In the main menu click on Settings > Design Parameters to bring up the dialog showing the design parameters per IRC, as shown in Figure W-19. Notice that since we are only working with Reinforced concrete, some of the fields for PT concrete are locked. Review the settings here, but since no changes are required, click cancel to close this screen and go back to the program. On the Design Tab, click on Rebar and in the Dialog which comes up, select Bar size MS25-GR1 and perform an autodesign. Program comes up with a rebar pattern as shown in Figure W-20. Click OK to accept and close the dialog.


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Next click on the Stirrups dialog and select MS12-GR1 for the stirrup size, 6 for number of legs and 150mm for spacing and do an auto design. Program comes up with a stirrup schedule which you could clean up to make it more construction-friendly and click OK to accept the reinforcement and also optionally copy this back to the model. You can view the results in CONBOX, by simply clicking on the Print icon in the toolbar to bring up the dialog shown below in Figure W-21.


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Figure W-21: Print dialog in CBX.

Now that the design of the superstructure is complete, Click OK to close CBX and transfer information back to the LEAP Bridge model for further processing of the substructure. Notice now that the reinf. has been updated in the superstructure (visible when the transparency option is selected in the 3D view). See figure W-22 below.


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Figure W-22: Rebar and representative stirrups in the 3D bridge model in LEAP Bridge. Click on save the project. Next click on the SubStructure tab, select AB01 in Abut/Pier list and then click on the RC-PIER button, all of the pertinent data is automatically transferred to RC-PIER and it is displayed as shown in Figure W-23 below. Let us now complete the input process in RC-PIER and complete the analysis & design of the substructure.


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Tutorial 3

Substructure design

Figure W-23: RC-PIER Project tab with information completed automatically. Switch to Geometry tab and note that all the geometry information is filled in correctly. Click on Abutment configuration. For this example, we will continue with Stem wall as defined in ABC wizard in LEAP Bridge.


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Figure W-24: Abutment configuration showing stem wall properties You can review the superstructure parameter information as imported from CONBOX. For this example, we need to define eccentric footing for stem wall. Click on Footing|Pile dialog and change the from column distance in z direction to 4.8 m as shown below.


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you For this example, we need to define the bearing locations. Click on bearing dialog and define the bearings at every 2m distance.


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Figure W25: Bearing data Select single bearing line option. Define the 1st bearing at 2 m from the cap left end. Define 2nd bearing at 2 m from the previous bearing location. Define 5 bearings. Click OK to accept these changes. The complete pier geometry can be reviewed in 3D view under geometry tab.


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Figure W-26: 3D Graphical view of pier You can rotate; zoom in/out using the graphical options given below the 3D view. You can switch to 2D view to copy or print the pier geometry. Next, move to load tab to define the load applied on pier and select the desired load groups as per IRC specifications. For this example, primarily you will consider dead, live, wind and braking force. Select dead load (G) from the list of loads available and click to select it. Select Dead load case (G) and click edit to open the load dialog. Click generate button to open the auto load generation options as shown in W-27 and select import load from superstructure option. Select the dead load G & SG to import the load on pier1, as shown in Figure W-28


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Figure W-27: Auto dead load generation dialog.


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Figure W-28: Dead load imported from superstructure

Upon clicking “Generate” button will distribute the dead load on bearings as shown in Figure W-29.


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Figure W-29: Load case dialog Click OK to accept these values and close the dialog. In the similar way, select live load and select generate load. Keep the default IRC rule option and import the live load reactions for Class A, 70 R from superstructure as these are already computed during superstructure design as shown in Figure W-30. Depending on the carriageway width, program generates numerous live load combinations based on IRC 6-2000 specifications. Among these generated combinations, it isolates the most critical combinations producing the maximum effect in the individual members. On the same dialog, select the option to generate longitudinal forces. This will generate the breaking force for each combination.


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Figure W-30: Live load generation

Click OK to accept the load cases. Note that, program has generated 7 critical live load combinations. You can click on “LL details” to check the details of each live load positioning. Note: You can edit the individual load case to check the bearing reaction, but if you click OK after editing, program erases the live load details descriptions.


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Figure W-31: List of selected loads Now, select wind load case (Ws) and click edit to generate the wind load forces on structures. Generate the wind load for multiple range of wind angle 30 to -30. You can generate the wind load force acting on live load simultaneously or independently. For this example, we will generate the wind on live load simultaneous by selecting wind acting on live load option. Depending on the bridge location, and pier elevation, correct wind pressure acting on substructure will be selected.


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Figure W-32: Wind load generation dialog Once all the required load cases are defined, select the Service I and Service IIIA, load groups. Next, move to analysis tab. Click on Analysis and design parameter to check the permissible stress values. For this example, we will not make any changes and use the default parameters. Select “Yes” to allow program to generate the default load combinations. You can review the analysis results for each load case or for particular combination at each specific member node.


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Figure W-33: Analysis results dialog Now, you are ready to design the individual components – the stem wall and footing according to IRC specifications. Switch to stem tab and select Autodesign. This prompts the dialog to select the rebar size. Select MS32- GRI and MS-6-GR1 for stirrup size. Program comes with its own reinforcement and stirrup schedule, which can be edited manually. Click on Design status to review the flexure, shear and torsion design. If at any locations, design fails, program flags that location.


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Tutorial 3

Figure W-34: Stem design tab Similarly, design the footing. In the footing design, you can use Autodesign as explained earlier or manually define the reinforcement. Depending on the footing type, this dialog will be slightly different. For combined footing, user can define the reinforcement start and end location. For this example, we have defined spread footing and will be using Autodesign and use 90 degrees hook on both sides to check the design status. You can design all the footing at the same time by checking the box for “Autodesign all “. Select FTG03 from the available list and click Autodesign. Use MS28-GR1.


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Figure W-36: Footing design tab You can view the results in RC-PIER by simply clicking on the Print icon in the toolbar to bring up the dialog shown below in Figure W-37.


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Figure W-37: Print dialog in RC-PIER. Now that the substructure design is complete, Click OK to close RC-PIER and transfer information back to the LEAP Bridge model. Notice now that the reinf. has been updated in the substructure (visible when the transparency option is selected in the 3D view). See figure W-38 below.


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Tutorial 3

Figure W-38: Abutment reinforcement display in 3D model of LEAP Bridge.


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Tutorial 4

Tutorial 4

Two Span CIP Post Tensioned I-Girder Bridge

Tutorial 4

Tutorial 4 Two-Span CIP Post-Tensioned I-Girder Bridge This tutorial is a step by step walkthrough of the analysis and design of a two-span cast-in-place posttensioned I-girder bridge using LEAP Bridge. The example illustrates the full lifecycle work flow starting with the basic modeling in the ABC Wizard, followed by detailed design of Span 1 Girder 1 (S1G1) using CONBOX. For the sake of brevity, the detailed step by step analysis and design of the abutments and pier is omitted from this example; please refer to other tutorials for details.



LEAP® Bridge Enterprise v13.0.0 Tutorial Four © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 4

Figure W-3: Bridge plan view showing span information

Figure W-4: Pier front and side views


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Tutorial 4

Bridge Data 3. Superstructure: Single-stage post-tensioned bridge. Concrete Properties Girder: fck, , at Initial stage (time of PT):

35 MPa

fck, , at Deck stage (Casting of Deck):

35 MPa

fck, , at Intermediate stage:

37 MPa

fck, , at Final stage (time of Live Load):

45 MPa

Deck: fck, , at Initial stage (time of PT):

0 MPa

fck, , at Deck stage (Casting of Deck):

0 MPa

fck, , at Intermediate stage:

30 MPa

fck, , at Final stage (time of Live Load):

35 MPa

Weight:

2400 kg / m3

Single Stage Post-tensioning Strand Properties Strand Type:

27T13, LowLax

Ultimate Tensile Strength. fp:

1,860 MPa

Area:

2,667.6mm2

Duct diameter:

D=105.9 mm


Fe415, HYSD Steel

Dead Load on Superstructure: 2 crash barriers (left and right) Live Load IRC Loading, Class 70R and Class A LEAP® Bridge Enterprise v13.0.0 Tutorial Four © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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Tutorial 4

Start of Tutorial

Start the LEAP Bridge software application by clicking on Start > All Programs > Bentley > LEAP Bridge. Set the Design Code to ‘India_IRC’ and fill in the general project information as shown in the figure below. The default units are preset to SI (Metric) units for the IRC code.

Figure W-5: Project tab information Click the Geometry tab, and start modeling the bridge using the ABC (automated bridge creator) Wizard. The Wizard can be launched simply by clicking on the ABC Wizard icon in the toolbar. Begin entering the information shown in Figure W-6 related to the bridge superstructure cross-section and span details. If detailed information about the geometry of the bridge including the alignment information, cross-section and vertical profile is available, this optional information can also be input at this stage. After completing the superstructure input, click on Next to move to step 2 and input information for the drop cap multi-column pier as shown in Figure W-7. The input is fairly straightforward and can be completed quickly by simply inputting the values for various input fields. If there are similar multiple piers, simply use the copy button to copy the current pier geometry to other piers.


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Figure W-7: ABC Wizard, Step 2, Substructure details (Pier) Once the input for the pier is complete, click on the Pier drop down in the top left hand corner of the window. Change the selection to “Abutment” and Number “1” and complete the input of abutment properties as shown in Figure W-8. Simply copy the Abutment Number 1 properties to the end abutment (Abutment Number 2) using the copy tool available on this screen.


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Figure W-8: ABC Wizard, Step 2, Substructure details (start abutment)

Next enter the values for the material properties as shown in figure W-9 below. These values will be used as defaults when data is transferred from LEAP Bridge to CONBOX or RC-PIER. After the initial model is built with these properties, the user will be able to override these default settings in the component programs.


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If all information for these three steps in ABC wizard is accurate, the status window will reflect the same, and you can press the finish button to complete the initial description and view the generated 3D model on the Geometry tab of LEAP Bridge as shown in Figure W-10. Now that the initial model has been created, you could play around with some of the viewing options such as rotation, zoom, and pan by either using the right mouse menu (context sensitive menu) or simply accessing the appropriate functions on the tool bar.


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Now is a good time to save the input. Click on File/Save and provide a name “workshop1.xml” to save the file. Next, click on the SuperStructure tab, and the click on the CONBOX button. All of the pertinent data is automatically transferred to CONBOX and CONBOX is displayed as shown in Figure W-11 below. Let us now complete the input process in CONBOX and complete the design of the superstructure.


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Figure W-11: CONBOX Project tab with information completed automatically.

The bearing offset with respect to the centerline of supports (Abutments and Piers) can be specified in the Bridge Component Layout dialog box by assigning values to LtBrgOff and RtBrgOff fields. The length of the Abutment can also be specified in this dialog; the length of the Piers can be defined in the Pier and Column Definition dialog box (Figure W-12).


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Figure W-12: Bearing Offset and Abutment Length definition

The deck and the haunch thicknesses, material properties for the deck and the girders at the various stages (Initial, Deck, Intermediate, and Final) and the girder type and the section variation at the ends of the girders – End Block and Taper Section details – can be specified in the Span Definition dialog box under the Geometry tab (Figure W-13).


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Figure W-13: Deck and haunch thickness, material properties for deck and girders, girder type, clearance, and section variation definition

Superimposed dead loads such as the crash barriers, footpath and wearing surface can be automatically added by specifying their sizes and material properties by clicking on the Crash Barriers button on the Geometry tab. Click on the Define buttons to view and change the dimensions. The dead load of the Items marked Include are automatically considered in the appropriate load groups for analysis. Click OK to close this dialog and view the updated section view showing the 2D graphics for the (Figure W-14).


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Figure W-14: Crash Barriers, Wearing Surface, Footpath, and Railing definition

Next click on the Model tab, and then the Tendon button and input the information for the tendon in Girder 1 in Span 1. The Tendon Type specified is 27T13. Tendons for all girders in all spans can be similarly specified (Figure W-15).


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Figure W-15: Tendon definition

Click OK to close this screen and move to the Loads and Analysis tab in CONBOX. By default all of the initial and final load cases, the appropriate loads and load factors all per IRC have already been predefined as shown in Figure W-16.


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Figure W-16: Load Combinations (for Final) In the figure above, the right hand side tree with the BR01 – Loads are the library of loads on this particular bridge, and they can be edited here, and all instances of those particular loads are automatically updated wherever they are used. To use these loads simply drag and drop them over to the left-hand pane in the appropriate Case – Initial, Deck, Intermediate, and Final – and the appropriate Combination – Service I, Ultimate I, etc. The right-click menu option allows the user to automatically add a particular load defined on the right side to all load combinations on the left side; if a load is already present in any load combination, duplication is avoided. You can verify and if required edit and modify the load factors for each combination. Simply double-click on the Load Combination name in the left hand side window to bring up a dialog which looks similar to the screen shown in Figure W-17.


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Figure W-17: IRC Load Combination Factors dialog, shown here for “Service I Final” Click on the Run Analysis button on the Loads/Analysis button to run the longitudinal analysis, for the dead loads, temperature loads, and the moving live loads defined under the Loads/Analysis tab. Once the Analysis is complete, the Run Analysis button turns into View Analysis and you could look at the detailed reports (either as graphs or tabular data). See Figure W-18.


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Figure W-18: View Analysis Results

Notice also that the program automatically switches you to the design tab, and shows the P-jack required vs. provided and also the initial and final concrete strengths required and provided as shown in Figure 18. Please select All Spans and All Girders if you would like to automatically export the girder reactions to RC-PIER. See Figure 19. Additionally, detailed design results can be viewed in tabular or graphics format by clicking on the Design Results button on the Design tab (Figure W-20).


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Figure 20: Detailed design results in the Design Results dialog

Click on Settings > Design Parameters in the main menu to bring up the dialog showing the design parameters per IRC, as shown in Figure W-21. Here Permissible stresses and other design requirements can be specified.


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Figure W-21: Design Parameters dialog

On the Design tab click on the Stirrups button and select HY12-GRII for the stirrup size, 2 for number of legs and 150 mm for spacing and do an auto-design. Program comes up with a stirrup schedule which you could clean up to make it more construction friendly and click OK to accept the reinforcement and also optionally copy this back to the model (Figure W-22). Similarly mild steel required in addition to the tendons can be automatically designed using the Rebar dialog on the Design tab. In this example, the specified tendon provides adequate flexural capacity and as such no additional mild steel is required.


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Figure W-22: Auto-design in Stirrups dialog You can view the results in CONBOX, by simply clicking on the Print icon in the toolbar to bring up the dialog shown below in Figure W-23


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Figure W-23: Print dialog for creating and printing reports

Now that the design of the superstructure is complete, close CONBOX via File/Exit or by clicking on the “X”. Select “Update LEAP Bridge Model” to transfer the information and the reactions back to the LEAP Bridge model. Once the model updated in LEAP Bridge the model information and the reactions from computed in CONBOX will be available for analyzing and designing the abutments and the pier using RCPIER. For transferring all necessary information, please select All Spans and All Girders for running the analysis in CONBOX before updating the LEAP Bridge model. LEAP® Bridge Enterprise v13.0.0 Tutorial Four © Bentley Systems, Inc. No part of this user manual may be reproduced in any form or by any means without the written permission of the publisher.

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The designed reinforcement can be seen in the Design tab of LEAP Bridge – visible when the transparency option is selected in the 3D view. See figure W-24.

Figure W-24: Tendons and representative stirrups in the 3D bridge model in LEAP Bridge


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