Field instrumentation and numerical analysis of an elliptical shaft constructed for the Texas Superconducting Super Collider Project

Abstract

This paper focuses on the field data interpretation and numerical analysis of an elliptical shaft constructed for the Texas Superconducting Super Collider Project. The instrumentation program consisted of measurements of lateral deformation, heave and pore pressure within the undoweled and predoweled reaches of the advancing shaft. The field measurements point to a blocky, post-peak response of the clay shale beneath the advancing shaft invert and indicate the importance of predoweling reinforcement in controlling progression of the blocky failure. The numerical analysis was performed based on an understanding of the rock mass response to excavation developed through analysis of field instrumentation data. The technique developed for simulating the impact of the blocky, post-peak response of the shale on the redistribution of stresses around the shaft opening was successful in describing the pore pressure response recorded beneath the shaft invert and has proven to be a useful tool in studying the redistribution of stresses in blocky materials.