In 1976 surface movement of 1.5 feet resulted from mine subsidence and severely damaged two school buildings south of Pittsburgh, Pennsylvania. A stabilization project was undertaken to arrest the subsidence so that reconstruction of the buildings could be accomplished. A detailed program of exploration and design was completed using core borings, borehole television, joint and fracture studies and rock mechanics analysis. From these studies, a stablisization design using powerplant flyash to fill the mine are and a modified foundation grouting program for the rock above the mine was developed. This project was the first time that this design concept, using a modified foundation grouting procedure, was used by the Pennsylvania Department of Environmental Resources for a mine subsidence stabilization project. A detailed post-construction analysis program was undertaken, including the installation and monitoring of several multiple point rod extensometers. The analysis indicated that the risk of future subsidence and surface settlement has been reduced to an acceptable level for redesign and reconstruction of the schools. (Author)

  • Supplemental Notes:
    • Proceedings of the Eighteenth Annual Engineering Geology and Soils Engineering Symposium, held at the Red Lion Inn, Boise, Idaho.
  • Corporate Authors:

    Idaho Transportation Department

    3311 W State Street, P. O. Box 7129
    Boise, ID  United States  83707-1129

    University of Idaho, Moscow

    Department of Geology and Geological Engineering
    Moscow, ID  United States  83844-3025

    Boise State University

    Department of Geology and Geophysics
    Boise, ID  United States 

    Idaho State University, Pocatello

    Department of Geology
    Pocatello, ID  United States  83201

    Idaho State University, Pocatello

    Department of Geology
    Pocatello, ID  United States  83201
  • Authors:
    • Branthoover, G L
    • Richards, J W
  • Conference:
  • Publication Date: 1980-4

Media Info

  • Features: Figures; References;
  • Pagination: p. 323-337

Subject/Index Terms

Filing Info

  • Accession Number: 00334075
  • Record Type: Publication
  • Created Date: Sep 16 1981 12:00AM