MODELING OF SINKHOLES IN WEAKLY CEMENTED SAND

Investigators studied sinkhole development in a profile with a weakly cemented sand overlain by an uncemented sand and underlain by a karst limestone. A total of 51 reduced-scale stress-correct centrifuge models were used in the study. The interaction between the thickness, cohesive strength, and unit weight of the cemented sand layer; the thickness and unit weight of the uncemented sand overburden; and the diameter of the cavity in the underlying karst formation was investigated. Collapse of the cemented sand layer into the underlying opening occurred either as a breakthrough plug with steeply inclined sides at an average angle of 61 deg to the horizontal or as dome fallout that left a stable arch. Model geometry determined the type of failure. A dimensionless design chart was developed to predict failure. The overburden pressure over the cavity at collapse was less than the geostatic overburden pressure. The fraction of full geostatic stress decreased with increasing overburden depth relative to the size of the cavity opening and approached an asymptotic value of approximately 5 percent.

Language

  • English

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: p. 998-1005
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00730037
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jan 1 1997 12:00AM