THE DFI MIDDLE EAST CONFERENCE 2012 Performance Based Approach for a Deep Excavation in Poor Subsoil Conditions - A Case Study *
H. TURAN DURGUNOĞLU, PhD., P.E., G.E., F. ASCE Emeritus Professor, Bogazici University / Istanbul / Turkey Chairman, Zetas Zemin Teknolojisi A.S. / Istanbul / Turkey email:
[email protected] Tel: 90-216-4844170
AKNOWLEDGEMENT This case study has been realized with the contributions of; • • •
•
Mr. Mr. Fatih Kulac, PE, CEO of Zetas, Mr. Mr. Selim Ikiz, PE, General Manager of Zetas, Mr Onder Akcakal and Berkay Kocak, PE, Engineering Group of Zetas, Mr Ali Gunay, Gunay, GE, Project Manager of Zetas
Special thanks are due to Project development group SURYAPI SURYAPI for their kind cooperation. Special thanks are due to; • • •
Mr. Mr. Altan Altan Elmas, General Manager of Suryapi Mr. Mr. O. Ramiz Soylu, Deputy General Manager of Suryapi Mr. Mr. Ismail Turkeli, Project Manager of Suryapi
AKNOWLEDGEMENT This case study has been realized with the contributions of; • • •
•
Mr. Mr. Fatih Kulac, PE, CEO of Zetas, Mr. Mr. Selim Ikiz, PE, General Manager of Zetas, Mr Onder Akcakal and Berkay Kocak, PE, Engineering Group of Zetas, Mr Ali Gunay, Gunay, GE, Project Manager of Zetas
Special thanks are due to Project development group SURYAPI SURYAPI for their kind cooperation. Special thanks are due to; • • •
Mr. Mr. Altan Altan Elmas, General Manager of Suryapi Mr. Mr. O. Ramiz Soylu, Deputy General Manager of Suryapi Mr. Mr. Ismail Turkeli, Project Manager of Suryapi
KAGITHANE DISTRICT : A New Investment Investment Area of ISTANBUL ISTANBUL
Kagithane known as Sadabad in the Past
(www.kagithane.bel.tr)
Kagithane known as Sadabad in the Past
(www.kagithane.bel.tr)
Kagithane River Rehabilitation Project; Sea water will be delivered with «Tunnel Project» to the Kagithane Creek Tunnel Project
Existing River Halic Bosphorus
BIG INVESTMENTS AND CHALLANGING PROJECTS ALONG KAGITHANE CREEK
• • •
Shopping Mall Project Office Projects Residence Projects
All are being constructed simultaneously on unfavorable soil conditions.
KAGITHANE SHOPPING MALL PROJECT SURYAPI •
•
• •
4 Basements + 4 Floors Perimeter 462 m
Total Construction Area: 70.000 m² Plot Area: 10.200 m²
KAGITHANE SHOPPING MALL PROJECT SURYAPI
KAGITHANE SHOPPING MALL PROJECT SURYAPI PLAN VIEW OF THE PLOT
KAGITHANE SHOPPING MALL PROJECT SURYAPI SECTION OF THE BUILDING
KAGITHANE SHOPPING MALL PROJECT SURYAPI SOIL PROFILE
Section 1 Clay –
Section 2 Clay + Bedrock –
KAGITHANE SHOPPING MALL PROJECT SURYAPI
SOIL PROPERTIES Layer Clayey Alluvium Sandstone Improved Soil (with Jet Grouting)
γ(kN/m³)
Ø’ (°)
c’ (kN/m²)
18 23
26 38
10 40
25 150
20
30
40
90
E50ref (Mpa)
KAGITHANE SHOPPING MALL PROJECT SURYAPI GOLDEN HORN (HALIC) CLAY ATTERBERG LIMITS Bore Hole
Depth
LL
PL
PI
USCS
S1
6.00-6.50
40
21.8
18.2
CL
S1
19.50-20.00
47.7
23.4
24.3
CL
S2
7.50-8.00
40.3
21.5
18.8
CL
S2
18.00-18.50
46
22.7
23.3
CL
S2
22.50-22.95
56.6
24.7
31.9
CH
S3
4.50-4.95
27
20.4
6.6
CL-ML
S3
15.00-15.50
31.7
20.1
11.6
CL
KAGITHANE SHOPPING MALL PROJECT SURYAPI PRELIMINARY (TENDER) DESIGN BY GEOTECHNICAL CONSULTING GROUP •
Depth of Shoring 17m
•
Ø80 cm Bored Piles
•
•
2 Rows Ø60 cm Jet Grout Columns 7 Rows of Prestressed Anchorages
KAGITHANE SHOPPING MALL PROJECT SURYAPI PRELIMINARY (TENDER) DESIGN BY GEOTECHNICAL CONSULTING GROUP
PRELIMINARY (TENDER) DESIGN BY GEOTECHNICAL CONSULTING GROUP MODELLING WITH PLAXIS
Excessive Displacement with Preliminary Design 280 mm (%1,6)
AN ALTERNATIVE SOLUTION (Section 1) •
•
•
•
•
5 m excavation + anchorge Soil Improvement with jet grouting 5 m berm and excavation to 17 m depth with a 1/1 inclined slope Construction of core part of the superstructure Excavation of remaining area to 17 m depth with strutting
ALTERNATIVE SOLUTION CONSTRUCTION PHASES
ALTERNATIVE SOLUTION CONSTRUCTION PHASES
ALTERNATIVE SOLUTION CONSTRUCTION PHASES
ALTERNATIVE SOLUTION CONSTRUCTION PHASES
ALTERNATIVE SOLUTION CONSTRUCTION PHASES
ALTERNATIVE SOLUTION CONSTRUCTION PHASES
ALTERNATIVE SOLUTION CONSTRUCTION PHASES
ALTERNATIVE SOLUTION - DISPLACEMENTS
•
Expected displacement was 72 mm (%0,4)
ALTERNATIVE SOLUTION - DISPLACEMENTS
•
Up to 100 mm (%0,6) displacement is encountered during construction due to erosion of the berm due to rainfall
100 (%0,6)mm << 280 (%1,6)mm (Expected displacement with tender design)
INCREASE OF DISPLACEMENTS WITH TIME
DESIGN FOR SECTION 2
COSTRUCTION OF PERMANENT DIAPHRAGM WALL
•
Water Stops are installed between diaphragm wall panels
COSTRUCTION OF PERMANENT DIAPHRAGM WALL •
•
Water Stops are installed with special hydraulic Stop-Ends
Stop-Ends are manufactured by Z Makine (sister company of ZETAS)
COSTRUCTION OF PERMANENT DIAPHRAGM WALL •
Water Stops are installed between diaphragm wall panels
HYDRAULIC STOPEND
TREMI PIPE
WATER-STOP
COSTRUCTION OF PERMANENT DIAPHRAGM WALL •
Permanent Diaphragm Wall Construction – Water Stop Installation
EXCAVATION PHASE
EXCAVATION PHASE – BERM WITH SOIL IMPROVEMENT
BASE FAILURE MEANWHILE THE EXCAVATION WORKS DUE TO SOFT CLAY AND HIGH WATER LEVEL
CLAY SUBSOIL
PROTECTION OF THE BERM
INSTALLATION OF THE STRUTS
INSTALLATION OF THE STRUTS
Slab/Foundation – Diaphragm Wall Connections
Epoxy Rebar Planting into diaphragm wall
SECTION 2 SIDE – CONSTRUCTION PHASE
GENERAL VIEW OF THE SITE AFTER CORE STRUCTURE CONSTRUCTION
SUMMARY AND CONCLUSIONS •
•
Presently various challenging projects are being constructed simultaneously along the Kagithane River where very poor soil conditions do exist. The case study presented has covered an engineering approach to meet required performance criteria limiting letaral displacements as a result of deep excavations in Kagithane Shopping Mall Project.
SUMMARY AND CONCLUSIONS •
•
Supporting system in the tender design for deep excavation provided by the Geotechnical Consulting Group has included bored piles and jet grout columns supported with prestressed anchorages. Preliminary calculations for the tender design displayed excessive lateral displacements (280mm, %1.6) as a result of: • •
E x i s t e n c e o f S o f t C l ay S u b s o i l Presence o f High Water Table
SUMMARY AND CONCLUSIONS •
•
•
As a result an alternative design was proposed to limit lateral displacements and to have acceptable Factor of Safety against base failure. The Alternative design has offered the possibility of meeting performance criteria (%0,6) further gave the advantage of complition of the work with a lower cost (about 20 percent) in comparison to tender design. Although the soil properties were very poor it was possible to excavate down to 17 m under very high ground water table with limited displacements and no potential base failure.
