TES - P - 122.11

3 1 0 2 , 1 2 y r a u n a J

January 21, 2013

TRANSMISSION ENGINEERING STANDARD STANDA RD

TES-P-122.11, Rev. 01

TABLE OF CONTENTS

1.0

SCOPE

2.0

GENERAL 2.1 2.2 2.3

3.0

TRANSMISSION LINE ACCESS ROAD 3.1 3.2 3.3 3.4 3.5

4.0

Design Criteria Finger Road and Pad

SLOPE PROTECTION AND SAND CONTROL 5.1 5.2

6.0

Geometric Design Criteria Access Road- Earthworks Requirements Road Intersections Routes Pipeline Crossings

STRUCTURE PAD 4.1 4.2

5.0

Requirements Geotechnical Information Plan and Profile Drawings

Oil or Emulsified Asphalt Rip-rap or Concrete Barrier

BIBLIOGRAPHY

FIGURE TE-2211-0100-00: ACCESS ROAD AND PAD FOR SUSPENSION/TANGENT STRUCTURE FIGURE TE-2211-0200-00: ACCESS ROAD AND PAD FOR TENSION/ANGLE STRUCTURES FIGURE TE-2211-0300-00: ACCESS ROAD AND PAD FOR H-FRAME STRUCTURES FIGURE TE-2211-0400-00: ACCESS ROAD AND PAD FOR MONOPOLE STRUCTURES FIGURE TE-2211-0500-00: ACCESS ROAD AND PAD FOR GUYED H-FRAME STRUCTURES FIGURE TE-2211-0600-00: ACCESS ROAD AND PAD FOR GUYED MONOPOLE STRUCTURES FIGURE TE-2211-0700-00: TYPICAL INTERSECTION FIGURE TE-2211-0800-00: UNPAVED CROSSING FOR ABOVE GRADE PIPELINES FIGURE TE-2211-0900-00: FINGER ROAD AND PAD FIGURE TE-2211-1000-00: FINGER ROAD ALONG MAIN ROAD/HIGHWAY

TESP12211R01/MAT

Date of Approval: January 21, 2013

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TRANSMISSION ENGINEERING STANDARD

1.0

TES-P-122.11, Rev. 01

SCOPE This Standard establishes the specific parameters and procedures for the design of unpaved access road, structure pad and slope protection from erosion/encroachment of transmission line Right-of-Way (ROW), for use in overhead transmission line system of National Grid Saudi Arabia.

2.0

GENERAL 2.1

Requirements Access to the transmission line ROW and along the transmission line requires various operations including construction of road approaches, filling of ditches, dozing trails, and other works depending on the type of terrain. Suitable road approaches are required for safe access of equipment and vehicles. Proper surface drainage shall be provided. For easier accessibility during construction and later for inspection, operation and maintenance of the transmission lines, unpaved access road shall be located as near as possible to transmission lines. All access roads, finger roads and structure pads shall be permanent for operation and maintenance purpose by National Grid Saudi Arabia.

2.2

Geotechnical Information Detailed soil investigation conducted along the centerline of the proposed transmission line shall serve as reference in the design of access road. The soil investigation report shall include the following:

2.2

2.2.1

Soil boring logs, sampling and testing

2.2.2

Ground surface and Ground Water observations

2.2.3

Moisture-Density relationship (Compaction details)

2.2.4

California Bearing Ratio (CBR) Test plots including CBR vs Dry Density

2.2.5

Recommendations

Plan and Profile Drawings The design of unpaved access road and structure pad shall make use of the transmission line plan and profile drawings, which show the left and right profile at 15 m away from the transmission centerline.

3.0

TRANSMISSION LINE ACCESS ROAD The unpaved transmission line access road shall be designed for adequate traffic volume to assure the safe movement of construction and maintenance equipment along the ROW.

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TES-P-122.11, Rev. 01

Design of access road shall take into account the grade and topographical conditions of the terrain to be traversed and shall be in accordance with the following requirements: 3.1

Geometric Design Criteria 3.1.1

Design Speed The geometric design features shall be in consistent with design speed of 48 km/h for transmission line access road for all types of terrain conditions.

3.1.2

Sight Distance The minimum stopping sight distance shall be 61 m based on the design speed. Coefficient (K) values of 28 for crest vertical curve and 35 for sag vertical curve shall be used in determining the length of vertical curves. K value is a coefficient by which the algebraic difference in grade shall be multiplied to determine the length of the vertical curve, which will provide smooth transition between tangent grade changes. Length of horizontal curves shall be calculated in accordance with “Geometric Design Guide” by American Association of State Highway and Transportation Officials (AASHTO)

3.1.3

Maximum Grades The maximum grades for different types of terrain based on the specified design speed shall be the following: Type of Terrain a. b. c.

3.1.4

Flat Rolling Mountainous

Maximum Grade 10.5% 13.5% 15.0%

Roadway Width The minimum width of the unpaved access road shall be 5 m.

3.1.5

Side Slope The maximum side slope shall be 4 horizontal to 1 vertical. The intersection of fill slope and cut slope planes shall be well rounded. The cut slope shall be designed with adequate and well-rounded ditches.

3.1.6

Minimum Clearances a.

TESP12211R01/MAT

The minimum horizontal distance from the centerline of transmission line to the nearest edge of the access road shall be 15 m as indicated in Figure TE-2211-0100-00. Date of Approval: January 21, 2013

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b.

3.1.7

The minimum vertical clearance between the highest point on the road surface and the lowest conductor of the overhead transmission lines shall conform to TES-P-122.09.

Path Required for Vehicle (10-meter long truck for line wash) a. b. c.

3.2

TES-P-122.11, Rev. 01

Turning radius Max. Angle of approach and departure Max. ramp break over angle

14.0 m 30 degrees 10 degrees

Access Road - Earthworks Requirements The typical cross-section of access road shall consist of subgrade, subbase, and surface/base course. The requirements are given below: 3.2.1

Subgrade a.

Clearing site and rough grading shall be as per TCS-Q-113.02. An average of about 200 mm top soil shall be removed from the subgrade, transported and disposed off from the site at National Grid Saudi Arabia designated dumping grounds.

b.

Any depressions below subgrade level due to removal of unsuitable material shall be filled in accordance with requirements of TCS-Q-113.02.

c.

The original ground (subgrade) shall be scarified and compacted to 200 mm depth. Compaction shall be in accordance with TCS-Q-113.02 as specified for Light Traffic roads. The compacted California Bearing Ratio (CBR) at laboratory for subgrade material after four days of soaking as determined by ASTM D1883 shall not be less than 15.

3.2.2

d.

The subgrade finish shall be conforming to the required alignment, grade and cross-section of the access road.

e.

In areas where the existing subgrade material has a CBR value of less than 15, subgrade modification shall be done to improve the CBR to a minimum of 15 after four days of soaking.

Subbase a. Subbase material shall be in accordance with Class C of TCS-Q-113.02. It shall be clean, free of organic and other deleterious substances. The CBR value of the material shall not be less than 50. b. Compaction shall be in compliance with TCS-Q-113.02 as specified for Light Traffic roads. Thickness of each layer shall not exceed 150 mm after compaction.

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3.2.3

TES-P-122.11, Rev. 01

c.

The top of the subbase material shall be minimum of 1.5 m in Sabkha, water logged, water course, flooded and swamp areas in order to protect the wearing surface from detrimental effects of capillary movement of the ground water. The thickness of the subbase material in other areas shall vary depending on the type of terrain to avoid abrupt changes in the finished grade and to provide smooth riding surface.

d.

The top of the subbase material shall be elevated minimum 750 mm from the existing ground level in desert area affected by sand shifting & sand dunes.

Surface/Base Course a.

Material Surface/base course material shall be in accordance with Class B of TCS-Q-113.02. It shall be free of organic matter, rubbles, cobbles, boulders and other deleterious substances. CBR value for surface/base course material shall not be less than 75.

b.

Placement and Compaction

Surface course shall be minimum 300 mm thick and the material shall be placed in layers of uniform thickness with approved spreaders. Layer thickness generally shall not exceed 150 mm after compaction. Compaction shall be as per TCS-Q-113.02 for Heavy Traffic roads. The water content of the material shall be maintained during placement at the optimum percentage (± 1½%) as determined by ASTM D 1557. Vibratory compactor or other approved types of special compacting equipment may be used. c.

Finish

The surface of the compacted material shall be finished by blading or with automated equipment specially designed for this purpose and rolled with a steel wheeled roller. Thin layers of fine materials shall never be added to the top layer of the surface course in order to meet the grade. d.

Tolerances

The top of the completed surface course shall not show any deviation in excess of 20 mm when tested with a 3 m straightedge. The completed thickness of the surface course shall be within ± 20 mm of the design thickness of 300 mm.

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3.3

TES-P-122.11, Rev. 01

3.2.4

Fill materials, including water used during compaction, shall have chloride and sulfate contents equal to or less than the existing soil. Seawater shall not be used for compaction.

3.2.5

In continuous/uninterrupted hilly areas where hard & solid bed rock is encountered, access road shall be prepared by rough grading at the existing levels followed by compaction in order to suit four wheel drive (4WD) vehicles. Such roads shall serve the purpose to access the structure locations during the construction stage and later on, same roads shall be utilized by National Grid Saudi Arabia for operation & maintenance. These roads shall be subject to approval and acceptance of National Grid Saudi Arabia.

Road Intersections Road intersection and access road crossing are locations where roads cross each other at a common elevation. The typical plan layout of intersection shall be as per Figure TE-2211-0700-00. Adequate advanced warning of the intersection, traffic directional arrows and signs shall be provided as per following: 3.3.1

Warning Signs The STOP or YIELD sign shall be provided to control traffic in accordance with Ministry of Transport (MOT) requirements and shall be placed on the access road at least 100 meters before the intersection.

3.3.2

Caution Signs The caution signs "WARNING ROAD CROSSING AHEAD, SLOW DOWN", shall be provided at least 100 m before the intersection and "NATIONAL GRID SAUDI ARABIA RIGHT-OF WAY; DO NOT ENTER" shall be provided at the barriers. The Sign boards shall be of 2 m X 1 m X 3 mm thick anodized aluminum plate, supported suitably by two 50 mm galvanized schedule 40 pipes. The top level of the sign boards shall be 2 m from the ground level. The lettering shall be in English and Arabic languages of 50 mm height in reflective Aluminum color in blue background.

3.3.3

Chain and Barrier Post (with locking arrangement) Chains and barrier posts shall be located as shown in Figure TE-2211-0700-00. Chains and barrier posts shall be painted with Zinc Yellow (RAL 1018) and Traffic Black (RAL 9017) stripes of reflective paint, to be visible at night, to prevent any untoward incident. Barrier post shall be steel pipe filled with concrete of minimum 400 mm diameter and 2.5 meters length. This shall be embedded one (l) meter in depth. Chain shall be of 6 mm size and grade 43 steel. The chain shall be fixed at one end of the barrier. A closed hook to be provided at other end of the barrier post for locking purposes.

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3.3.4

TES-P-122.11, Rev. 01

Crash Barrier Crash barriers are required to protect any fence, boundary wall, culvert, or any other utilities, which are close to the transmission line structures. Crash barrier shall be in compliance with TES-P-119.19.

3.4

Routes Access road shall be routed within the ROW of the proposed transmission lines.

3.5

3.4.1

If an access road already exists within 30 m from the proposed transmission line, only finger roads need to be constructed in order to access the new transmission line structure.

3.4.2

The existing access road shall be upgraded as per requirements of this standard. Precautionary measures to be taken in order to avoid any damage to the existing access road. Any damage during construction shall be repaired/rectified without any extra cost to National Grid Saudi Arabia.

3.4.3

Existing roads of Saudi Aramco, Saline Water Conversion Corporation (SWCC), Ministry of Transport (MOT) and Municipality shall not be used as transmission line access road.

Pipeline Crossings Pipeline crossings shall be designed to provide safe passage of vehicular traffic in accordance with latest Saudi Aramco and SWCC standards. Following requirements of pipeline crossing shall be fulfilled unless otherwise specified by the owner. 3.5.1

The minimum basic wheel load for the pipeline crossings shall be seven (7) metric tons.

3.5.2

The crossing shall be made perpendicular to the pipeline as much as possible. Saudi Aramco and SWCC standards shall be complied.

3.5.3

The pipeline shall be protected against damage from vehicle collision by means of at least 1 m high stabilized earth berm over the pipe and extending 30 m beyond both edges of the road (measured perpendicular to the road).

3.5.4

Backfill material shall be the same material as that of access road (as specified in section 3.2) and shall be free of material that may damage coatings of steel pipe. Backfill shall be placed in layers of 300 mm or less and the degree of compaction shall be same as for the access road.

3.5.5

Unless otherwise specified, the minimum cover over steel pipes shall be 1.5 m for unpaved road crossing.

3.5.6

The minimum width of the crossing shall be 5 m, excluding the side slopes.

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TES-P-122.11, Rev. 01

Typical pipeline crossing details are shown on Figure TE-2211-0800-00. 4.0

STRUCTURE PAD 4.1

Design Criteria The standard earthworks requirements of the subgrade, subbase and surface/base course for the design of transmission line structure pad shall be same as for access road, (as stated in section 3.2 of this standard) along with the following requirements: 4.1.1

The edge of the pad shall have a minimum distance of 15 m from any point of the structure foundations or guy anchors.

4.1.2

The maximum side slope shall be 4 horizontal to 1 vertical. Side slopes shall be as flat as possible, to increase safety by providing additional maneuver area in emergencies and maintenance work.

4.1.3

Structure pads shall be graded to drain water away from structure foundations with slope of 1.5 to 2 percent.

4.1.4

For concrete foundation, top elevation of concrete footings shall be minimum 450 mm above finished grade of the structure pads unless otherwise specified in relevant Scope of Work and Technical Specification (SOW/TS).

4.1.5

Wherever the transmission line is passing through Sabkha, water logged, water course, flooded and swamp areas; the filling shall be done to get structure pad at minimum elevation of 1.5 m above the surrounding area.

4.1.6

The typical design drawings of structure pad for different transmission line towers shall be as shown in Figure TE-2211-0100-00 to TE-2211-0600-00.

4.1.7

The top of the subbase material for structure pad shall be elevated minimum 750 mm from the existing grade level in desert area affected by sand shifting & sand dunes.

4.1.8

In continuous/uninterrupted hilly area where hard & solid bed rock encountered, the structure pad shall be prepared by rough grading at existing levels followed by compaction with suitable equipments in order to access the structure locations.

4.1.9

The top of structure pad located in wadi or water channel/streams shall be higher than the highest expected wadi flood level by 350 mm. The sides of structure pad shall be stabilized and protected. All approvals shall be obtained from National Grid Saudi Arabia prior to start of construction works.

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4.2

TES-P-122.11, Rev. 01

Finger Road and Pad The typical details of finger road and structure pad are shown in Figure TE-2211-0900-00. Finger road shall not be taken from the existing roads of Saudi Aramco, SWCC, MOT and Municipality. Finger road shall be developed as shown in Figure TE-2211-1000-00.

5.0

SLOPE PROTECTION AND SAND CONTROL Protection of slopes adjacent to structure pads shall be carried out, where such slopes are liable to be washed away or eroded by wind. Erosion control is required when slope or excavation is steeper than 1½ horizontal to 1 vertical. Slopes shall have contour trenches for each 2 meters change in elevation. These shall be 0.4 meters deep and of rough construction. The following are the recommended methods of slope protection and sand control. 5.1

Oil or Emulsified Asphalt Sand encroachment/erosion on the structure pads and access roads shall be prevented by spraying the specified areas along the right-of-ways with crude oil or other approved compound such as slow setting asphalt emulsion meeting the requirements of ASTM D 2397 for CSS-Ih, to stabilize the surface. Spray area shall not be less than 20 m radial distance from the edge of access road/structure pad and finger roads. The crude oil shall penetrate a minimum of 13 mm which requires approximately 2 eight (8) liters/m , of surface. Emulsified asphalt shall be applied per manufacturer's recommendations.

5.2

Rip-rap or Concrete Barrier In wadi areas where ground water level is high, or in areas submerged with water, rip-rap or concrete barrier/lining shall be constructed within ROW to protect access road and structure pad from erosion. 5.2.1

Rip-rap shall be placed on the slopes of structure pads and in places along the slopes of access road where erosion control is required, and shall be of 2 durable stones or hard rocks. The geotextile (min. mass 200 gm/m Tensile & Elongation in compliance with ASTM D 4632) shall be placed beneath the rip-rap in order to maintain the separation between rip-rap and underlying soil. Proper size of stones to be pitched in sequence to protect geotextile membrane. Rip-rap shall be uniformly distributed to produce a compact rip-rap with a minimum thickness of 300 mm. The minimum specific gravity of stone shall be 2.5 and the maximum absorption shall be six (6) percent. The loss by abrasion shall not be greater than 45% when subjected to 500 revolutions in a Los Angeles Abrasion Machine in accordance with ASTM C131.

5.2.2

Concrete barriers shall be designed to protect the slopes of structure pads from erosion.

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5.2.3

6.0

TES-P-122.11, Rev. 01

Small stretches of access roads which are lower than the normal level, and where there is difference of levels on two sides of access road, box or pipe culverts with wing walls shall be used. The concrete shall be severe exposure type per 70-TMSS-03. The design shall be carried out based on site conditions, approved by National Grid Saudi Arabia.

BIBLIOGRAPHY

6.1

Highway Engineering Standard Handbook for Civil Engineers by Frederick S. Merritt

6.2

Geometrical Design Guide American Association of State Highway and Transportation Officials (AASHTO)

6.3

ASTM C 131 Standard Test Method for Resistance to Degradation of small-size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine

6.4

ASTM D 1241 Standard Specification for Materials for Soil Aggregate Sub-base, Base and Surface Courses

6.5

ASTM D 1557 Standard Test method for Laboratory Compaction Characteristics of Soil

6.6

ASTM D 1883 Standard Test Method for CBR (California Bearing Ratio) of Laboratory – Compacted Soils

6.7

ASTM D 2397 Standard Specification for Cationic Emulsified Asphalt

6.8

ASTM D 4632 Standard Test method for Grab Breaking Load and Elongation of Geotextiles.

6.9

SAES-L-460 Saudi Aramco Engineering Standard for Pipeline Crossings under roads and rail roads.

6.10

TES-H-107.02 Paint Color Codes and Standards

6.11

TES-P-122 Transmission Line Engineering Standards

6.12

TCS-Q-113.01 Asphalt Concrete Paving

6.13

TCS-Q-113.02 Earthworks

6.14

70-TMSS-03 Normal Weight Ready-Mixed Portland Cement Concrete

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0100-00: ACCESS ROAD AND PAD FOR SUSPENSION/TANGENT STRUCTURES

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0200-00: ACCESS ROAD AND PAD FOR TENSION/ANGLE STRUCTURES

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0300-00: ACCESS ROAD AND PAD FOR H-FRAME STRUCTURES

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0400-00: ACCESS ROAD AND PAD FOR MONOPOLE STRUCTURES

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0500-00 ACCESS ROAD AND PAD FOR GUYED H-FRAME STRUCTURES

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0600-00: ACCESS ROAD AND PAD FOR GUYED MONOPOLE STRUCTURES

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0700-00: TYPICAL INTERSECTION

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TES-P-122.11, Rev. 01

FIGURE TE-2211-0800-00: UNPAVED CROSSING FOR ABOVE GRADE PIPELINES

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TES-P-122.11, Rev. 01

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TES-P-122.11, Rev. 01

FIGURE TE-2211-1000-00: FINGER ROAD ALONG MAIN ROAD/HIGHWAY

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TES - P - 122.11

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