CALCUTTA METRO: CONTRACT SECTION 16B

A description is given of contract section 16b of the Calcutta metro which covers a stretch of cut-and-cover construction directly below a rail-over-road bridge. Neither rail nor road traffic could be suspended during construction and the excavation, which is in saturated sand with a high groundwater table, had to be carried out to a far greater depth than the bridge foundations, and very close to them. The use of cranes or other tall equipment was ruled out because of headroom restrictions. Wellpoint dewatering was not favoured for fear of settlement of the bridge foundations, and extraordinary measures were therefore called for. The methods adopted for side retention were basically variations of diaphragm walling and bored piling, using tripods instead of cranes. Excavation and concreting had to be carried out below water to a large extent. This paper discusses the gradual evolution of the methods adopted in the course of solving the problems faced during construction. (Author/TRRL)

• Corporate Authors:

  Thomas Telford Limited

  London,   United Kingdom 
• Authors:
  • Roy, T
• Conference:
  • Institution of Civil Engineers, Proceedings, Pt 1
• Publication Date: 1983-11

Media Info

• Features: Figures; Photos; References; Tables;
• Pagination: p. 871-883
• Serial:
  • Volume: 74

Subject/Index Terms

• TRT Terms: Construction; Construction management; Cut and cover tunneling; Design; Diaphragm walls; Excavation; Excavations; Foundations; Groundwater; Percent saturation; Sand; Slurry trenches; Subways; Tunneling; Tunnels; Water table
• Geographic Terms: India
• Old TRIS Terms: Subway construction
• ITRD Terms: 3666: Construction method; 3395: Cut and cover; 5907: Degree of saturation (mater); 9011: Design (overall design); 5155: Excavation (process); 4383: Ground water; 8045: India; 4105: Sand; 3358: Slurry trench wall; 3374: Tunnel; 1191: Underground railway
• Subject Areas: Bridges and other structures; Construction; Design; Highways; Hydraulics and Hydrology; Public Transportation; I25: Design of Tunnels; I54: Construction of Tunnels;

Filing Info

• Accession Number: 00382762
• Record Type: Publication
• Source Agency: Transport Research Laboratory
• Files: ITRD, TRIS
• Created Date: Apr 30 1984 12:00AM