Ground support technology for highly stressed excavations. Integrated theoretical, laboratory and field research / Технология крепления грунта при выемке грунта с высокой нагрузкой. Комплексные теоретические, лабораторные и полевые исследования

The continued and growing worldwide demand for minerals means that mining operations are being conducted at ever-increasing depths. Safe and efficient mineral extraction at depth is accompanied by significant engineering problems that require the modification of existing practices and the development and implementation of new technologies. This book is timely in that it attempts to address a particularly difficult problem—maintaining the stability of production and infrastructure excavations under changing static and dynamic conditions.
Mineral deposits are geological anomalies situated within a host rock mass, commonly structured by a network of mutually intersecting discontinuities. As depth increases, in situ stress increases along with the chance of two types of instabilities which are mechanisms of stress relief and manifest at the free surfaces of excavations. Firstly, there is the possibility of fracture through otherwise intact rock at excavation surfaces. Secondly, there is the possibility of violent detachment of rock blocks formed by discontinuities that intersect the free surfaces. In low-stress, quasi-static environments, instability has been successfully managed by installing arrangements of artificial reinforcement and support. However, at depth, the current design and implementation procedures for these treatments produce inadequate results. The geometry of the rock structure is stochastic and, together with high stress produces a very difficult dynamic problem.
The research programs used to define the dynamic demand of the rock and the dynamic capacity of artificial reinforcement and support provide the framework of this book and demonstrate the use of the scientific method to solve a non-trivial engineering problem. The work involved a multidecade research program comprising a considered sequence of field observations, in situ testing programs, laboratory testing programs and theoretical developments that reconcile with the results, all leading to a computer design methodology with the final proof of validity demonstrated by extensive, full-scale field trials. Each topic has been researched with sufficient and necessary detail to allow firm recommendations to be made on the basis of systematic investigations, observations and formal conclusions <...>