WATER INTRUSION IN UNDERGROUND STRUCTURES. APPENDIX VOLUME. FINAL REPORT

This report summarizes an investigation of problems related to water intrusion in underground structures of the Washington Metropolitan Area Transit Authority. Design and construction of the system has been evolving continuously since 1966 and has included a number of innovative features as well as certain special problems related to control of leaking water. The assignment was to investigate four topics of water intrusion: (1) the buildup of hydrostatic pressures and measures for pressure relief; (2) waterproofing procedures in the Metro system and their effectiveness; (3) the special problem of calcification due to precipitation of carbonates in the drainage system of rock tunnels; and (4) special difficulties with the intrusion of acid water in Coastal Plain deposits. The assignment included contacting other rapid transit agencies to evaluate their methods of treating water intrusion. A field test of waterproofing compounds was performed at Dupont Circle and Rosslyn Stations to evaluate the possible effect of sealing of drains in those stations by calcareous precipitates. Studies of the effect of buildup of water pressures indicated little possibility of significant stress increase in the rock station structural lining. An on-going investigation of the effect of acid water intrusion disclosed the abatement of these problems by a natural process of groundwater flushing.

• Corporate Authors:

  Washington Metropolitan Area Transit Authority

  600 Fifth Street, NW
  Washington, DC  United States  20001

  Urban Mass Transportation Administration

  400 7th Street, SW
  Washington, DC  United States  20590
• Publication Date: 1988-10

Media Info

• Features: Photos; Tables;
• Pagination: 140 p.

Subject/Index Terms

• TRT Terms: Groundwater; Hydrostatic pressure; Leakage; Tunnels; Underground structures; Waterproofing
• Identifier Terms: Urban Mass Transportation Act; Washington Metropolitan Area Transit Authority
• Old TRIS Terms: Calcification; Groundwater control; Umta section 6
• Subject Areas: Bridges and other structures; Construction; Public Transportation;

Filing Info

• Accession Number: 00480700
• Record Type: Publication
• Source Agency: Urban Mass Transportation Administration
• Report/Paper Numbers: UMTA-DC-06-0374-88-2, T17908
• Contract Numbers: UMTA-DC-06-0374
• Files: TRIS, USDOT
• Created Date: Mar 31 1989 12:00AM