Analysis of Deep Underground Tunnels and Intersections Including Key Block Theory with Equilibrium Analysis; DNA-TR-88-108

xxiii, [1], 593, [3] pages. Illustrations (over 180 figures and 14 tables). Formulae. Footnotes. List of References. Appendices. Front cover has the WARNING: This document contains technical data whose export is restricted by the Arms Export Act (Title 22, U.S.C., Section 2751, et seq.) or the Export Administration Act of 1979, as amended, Title 50, U.S.C. App. 2401 et seq. This work was sponsored by the Defense Nuclear Agency. To represent block-liner interaction in hard, jointed rock the Goodman-Shi key block theory was extended to 3-D. This work was synthesized with dynamic, nonlinear finite element in order to capitalize on the advantages with the latter affords in modeling geometry of the liner and constitutive properties of rock between joints. Under this project, synthesis was completed in 2-D and was nearly completed in 3-D. to supplement the finite element models, a dynamic equilibrium model of key blocks was developed which utilized the Kirsh solution for stress distribution around an opening; this model is suitable for design, and, if properly developed, can be regarded as the analog in jointed rock of Hendron-Aiyer. The report describes analysis of a.45 degree y-Intersection which was designed by SRI International. Block theory is a geometrically based set of analyses that determine where potentially dangerous blocks can exist in a geological material intersected by variously oriented discontinuities in three dimensions. It applies ideally to hard, blocky rock in which blocks of various sizes may be potential sources of load and hazard in an excavation or foundation. Weidlinger Associates, Inc., was a U.S.-based structural engineering firm that designs and rehabilitates buildings, bridges, and infrastructure and provides special services in applied science, forensics, and physical security. Weidlinger's clients include corporations, private clients, institutions, and federal, state and local governments. Dr. Jeremy Isenberg succeeded Paul Weidlinger as president and CEO in 1993. Jeremy Isenberg is a Consulting Professor at Department of Civil and Environmental Engineering, Stanford University and is recognized for his technical contributions in nonlinear structure-medium interaction and blast loading; evaluation of sensitive equipment to ambient vibrations; seismic performance of pipelines and related structures; and modeling of concrete for dynamic, finite element analysis of complex structures. His ideas and implementation led to integration of design with hardness assessment of such structures and exploited, for the first time for such structures, confined concrete to achieve greater strength and ductility. The same techniques have been adapted in the post-cold war era to retrofit structures to resist explosions from conventional weapons and terrorism. For this and related work in computational structural dynamics, he received the 1997 Ernest E. Howard Award of ASCE. Data he collected from US earthquakes on the seismic performance of pipelines using utility maps, repair reports and interviews clarified the relationship between maintenance of water pipelines and their seismic performance. For his contributions to seismically resistant pipelines and to lifeline earthquake engineering generally, he received the 1998 C. Martin Duke Award of ASCE. Beginning in 1989 he initiated a PC-based modeling system to verify inspection coverage using ultrasound for detecting flaws in reactor pressure vessels. In 1999 he was elected to the U.S. National Academy of Engineering, which cited him for contributions both to protective construction and lifeline earthquake engineering. In 2007 he was elected an Honorary Member of ASCE. He is the 2009 recipient of the ASCE Outstanding Projects and Leaders lifetime achievement award in design. He is the author of over 60 publications. Among the topics addressed in this report are: Underground Excavations, Finite Element Modeling, Jointed Rock Models, Structurally-Controlled Stability, Blo.…