Dynamic response of an opening in jointed rock

• Published in: International journal of rock mechanics and mining sciences (Oxford, England : 1997) Vol. 35; no. 8; pp. 1021 - 1035
• Main Authors: Gran, J.K., Senseny, P.E., Groethe, M.A., Chitty, D., Trulio, J.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.1998; Elsevier Science
• Subjects: Applied sciences; Buildings. Public works; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Engineering geology; Exact sciences and technology; Geotechnics; Soil mechanics. Rocks mechanics; Dynamic response; Stress analysis; Rock mechanics; Instruments; Limestone; Speed measurement; Experimental study; Accelerogram; Wave propagation; Opening; Failure analysis; Explosive fracturing; Properties of materials; Jointed rock; Numerical simulation
• ISSN: 1365-1609; 1873-4545
• DOI: 10.1016/S0148-9062(98)00163-6

A large-scale test was performed on a 0.4 m diameter lined cylindrical opening in a 2 m cube of jointed limestone for the purpose of gathering data to develop and validate computational models for the dynamic response of structures in jointed rock. The limestone cube was assembled from over four thousand 51 mm square×0.6 to 1.2 m long limestone bricks and was then embedded in a concrete test bed and loaded explosively with a 100 MPa, cylindrically diverging stress wave. The material velocity around the boundary of the jointed limestone cube was measured with accelerometers and these data were used to generate a continuous velocity boundary condition that can be used for computational simulations. Additional instrumentation measured stress in the limestone, joint slip and deformation of the opening. After the test, the limestone cube was recovered and carefully disassembled to reveal fracture patterns in the limestone bricks. Vertical fractures emanating from the springlines formed a chimney of bricks that slipped measurably relative to the rest of the rock mass above the opening and to a lesser degree below the opening.