A Method For Designing Deep Underground Structures Subjected To Dynamic Loads

This report describes solutions to a class of dynamic elastoplastic problems that model some of the salient features of the response of hardened underground facilities in rock. The theoretical model consisted of multilayered concentric cylinders of elastoplastic materials with time-dependent loads applied to the exterior boundary. Each element in the cross section was assumed to be incompressible and its yield governed by a Mohr-Coulomb failure criterion. The number of elements within the cross section was not limited. Solutions of the theoretical model were cast in the general form normally used in structural dynamics: Mass x Acceleration = External applied load - Internal resistance. The resulting equations can be quickly and inexpensively evaluated on a digital computer. To extend the range of validity of the exact theory, a first-order correction factor was developed to account for the compressibility of the materials, and a simple method to treat backpacked structures was introduced. The theory was verified by comparing calculated values with experimental measurements from small-scale static and explosively driven tunnel collapse studies. Good agreement was noted for all cases considered. (Author).

This book presents the most up to date information relevant to the design and instrumentation of underground structures. The structure might be a tunnel, shaft, cavern, or pressure unit, or a combination thereof. Empirical, rational, numerical, convergence and confinement, and discontinuity analysis methods are treated comprehensively. Special chapters are devoted to underground structures in rock burst, swelling, squeezing, and seismic zones. Water control, instrumentation, and tunneling through soft ground are also treated extensively. Sections on the design of pressure tunnels, shafts, caverns, shotcreting, water control, and soft ground tunnels are informative and authoritative. Worked examples are included on the design of rock tunnels, soft ground tunnels, and the treatment of underground structures through difficult ground. Extensive references are provided, and figures, sketches and photographs aid presentation. Important tables on planning, and case histories, allow the reader to build confidence in his design of underground structures. The book will be beneficial to civil, structural, geotechnical and mining engineers, geologists, and planners and managers associated with the design and construction of underground structures.