TORONTO SUBWAY EXTENSION CUTS ACROSS RIVER VALLEY

THE PROBLEMS CAUSED BY A HIGH WATER TABLE UNDERLYING SILTY FLOOD PLAIN SOILS ARE BEING OVERCOME ON A 2300-FOOT SECTION OF TORONTO'S SUBWAY. THE JOB CALLS FOR EXCAVATION OF SILTY FILL TO AN AVERAGE DEPTH OF 35 FT PLUS CONSTRUCTION OF THE CONCRETE SUBWAY TUBE SECTIONS. TWO PARALLEL LINES OF SOLDIER PILES WERE DRIVEN, BETWEEN WHICH HEAVY TIMBER LAGGING WAS FITTED FOR SHORING PURPOSES. SOILS ENCOUNTERED WERE GENERALLY DENSE FINE SAND AND SILT, WITH ONE PROBLEM AREA OF HARD CLAYEY SILTS AND GLACIAL TILL. TO COPE WITH THE DRAINAGE PROBLEM CAUSED BY THE HIGH WATER TABLE, AN EDUCTOR DEWATERING SYSTEM WAS INSTALLED (DESCRIBED COMPLETELY IN THE ARTICLE). THIS SYSTEM IS EFFECTIVE AT MUCH GREATER DEPTHS THAN WITH CONVENTIONAL PUMPS. BECAUSE OF THE HIGH WATER TABLE, THE TUNNEL WILL HAVE A TENDENCY TO FLOAT. CONCRETE BALLAST IS BEING ADDED TO PREVENT THIS. /CGRA/

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00179426
• Supplemental Notes:
  • Vol 13, No 18, PP 10-12, 7 PHOT
• Authors:
  • Rooke, W
• Publication Date: 1969-5

Media Info

• Serial:
  • Heavy Construction News
  • Publisher: Maclean-Hunter Limited
  • ISSN: 0017-9426

Subject/Index Terms

• TRT Terms: Concrete; Drainage; Ejectors; Excavations; Fills; Flood plains; Silty loams; Subways; Tubing; Water table
• Uncontrolled Terms: Extension
• Old TRIS Terms: Eductors
• Subject Areas: Construction; Highways; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00214644
• Record Type: Publication
• Source Agency: CANADIAN GOOD ROADS ASSOCIATION
• Files: TRIS
• Created Date: Apr 16 1970 12:00AM