In Situ Tests for the Determination of Rock Mass Shear Strength

摘要

Rock shear strength is often determined from in situ tests. Many cases have been reported in the literature describing in situ shear test procedures and test results. The purpose of this report is to summarize this information for guidance in planning and evaluating such tests. The types of tests discussed are: direct shear test, Triaxial or multiaxial test, torsion shear test, and pull-out test. The direct shear test is most widely used, and some 48 case histories of such tests are summarized in Appendixes A through E. The main advantage of the direct shear test is the ability to measure the shear resistance in any desired direction along potentially critical discontinuities. The test is also popular due to its adaptability to field conditions; tests can be conducted in trenches, adits, tunnels, and even calyx drill holes. (Author)