Rock Mechanics Instrumentation Trans Koolau Pilot Tunnel

"...Unfortunately, the research activities in soil mechanics had one undesirable psychological effect. They diverted the attention of many investigators and teachers from the manifold limitations imposed by nature on the application of mathematics to problems in earthwork engineering. As a consequence, more and more emphasis has been placed on refinements in sampling and testing and on those very few problems that can be solved with accuracy. Yet accurate solutions can be obtained only if the soil strata are practically homogeneous and continuous...." This statement about soil mechanics was made by Karl Terzaghi, thirty years ago and applies to a greater degree today to the infant science of rock mechanics. More uncontrolled variables are added to the already many existing in soil mechanics. Variables, such as Macro-discontinuity and in situ stress levels. In no other field of engineering are the problems as site oriented. Presently this site dependance demands the investigator or rock mechanics engineer to get his hands dirty rooting in the muck of a tunnel floor trying to properly install or readout test apparatus in a comprehensive site investigation. This paper discusses such a site investigation designed to determine the problems and solutions inherent in the driving of the Trans Koolau Tunnel. The paper will describe the various types of tests to be performed, how the results are to be used and the interrelation of the various tests themselves.