THE ENGINEERING IMPLICATIONS OF RISING GROUNDWATER LEVELS IN THE DEEP AQUIFER BENEATH LONDON

This report examines the rise in the level of the groundwater in the sands and the chalk below London. During the past two centuries, the pumping from the deep aquifer lowered the groundwater level by as much as 70 metres. The level is now rising, in many areas by about 1 metre a year. If the rise continues for 20 to 30 years, the water pressures in the sand and clays above the chalk will increase, causing ground movements in the clays. These pressure changes and movements could damage some large buildings and tunnels in central London and increase leakage into them. This report identifies the areas of London most likely to be affected and provides guidance for engineers. The potential effects on tunnels and shafts are examined. If water levels continue to rise, tunnels under London will suffer water ingress, deformation, and minor cracking and spalling. The problems will arise where tunnels are located near the base of London Clay or in the Lower London Tertiaries. There are at least 130 km of tunnels in these zones. A figure of 8 million is recommended for structural repair. These problems could be avoided if the groundwater level in the aquifer in Central London were held below about -20 mOD.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0860173038
• Corporate Authors:

  Construction Industry Research & Information Assoc

  6 Storey's Gate
  London SW1P 3AU,   England 
• Authors:
  • SIMPSON, B
  • Blower, T
  • Craig, R N
  • Wilkinson, W B
• Publication Date: 1989

Language

• English

Media Info

• Pagination: 116 p.
• Serial:
  • CIRIA SPECIAL PUBLICATION
  • Issue Number: 69
  • Publisher: Construction Industry Research & Information Assoc

Subject/Index Terms

• TRT Terms: Costs; Flow; Groundwater; Hydrologic phenomena; Loss and damage; Porosity; Seepage; Tunnels; Water table
• Uncontrolled Terms: Increase
• ITRD Terms: 224: Cost; 1614: Damage; 4323: Discharge (flow); 4383: Ground water; 9032: Increase; 5938: Porosity; 4315: Seepage; 3374: Tunnel; 4394: Water table
• Subject Areas: Bridges and other structures; Finance; Hydraulics and Hydrology;

Filing Info

• Accession Number: 00498515
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• ISBN: 0-86017-303-8
• Files: ITRD, TRIS
• Created Date: Sep 30 1990 12:00AM