The cost of drilling a geothermal well is significantly higher than the cost of drilling an oil and gas well at comparable depths. the higher cost is due principally to twofactors: the hardness of the rock formations being drilled and the high temperatures encountered in drilling. these two factors… More

In the united states, the technology for comminution of oresand other materials has been essentially stagnant for the last century. the grinding mills used are less than 5 per cent efficient in terms of energy usage and they consume an estimated 15 billion kwh of electrical energy per annum.… More

Preshocked preconditioning of tuff may occur in two manners at the nevada test site. first, the material is "preshocked" in a lineof-sight type underground nuclear test by the first wave passage. the second manner may occur as a result of areal space limitations when a second event is sited within a… More

Shear displacement along rock mass discontinuities (joints) under saturated, undrained conditions is one of the critical failure modes for a dynamically loaded deep base structure. the failure mode has not been experimentally simulated for deep base conditions. the combined application of normal and… More

Current egress boring machines, utilizing conventional 17-inch disc cutters, are capable of achieving maximum advance rates of 80 feet per hour, because of cutter limitations. the air force has determined that national needs require substantially faster boring rates. also, it is crucial that the… More

Deep-based icbm sites must be maintained at a constant working temperature for the benefit of personnel and sensitive electrical equipment within the facility. however, heat is generated within the facility from a variety of sources and there is a natural flow of heat from the warm rock mass… More

There is an emphatic need for research into innovative techniques/materials to repair and rehabilitate our nation'sexisting concrete roadways, bridges and building systems. present methods/materials employed generally result in inadequate service life of the repairs. one of the dominantfactors… More

Current methods used to measure strain at high temperatures depend on undesirable attachments, extensions, or indentations of the test samples. this study will investigate the use of new technology to apply high temperature coating marks to test samples. these applied marks will act as a reference… More

A one-million pound compression reaction loader is required to operate in conjunction with the waterways experiment station 6-kbar triaxial test device. terra tek has designed and constructed similar test systems for in-house testing. terra tek has also developed unique computer control codes… More

The navy is developing methods to determine the size and type of defects in helicopter gearboxes. with this knowledge a better understanding of the fatigue-crack propagation characteristics of the gears and bearings will be possible and enhance the accuracy in predicting the fatigue life. the… More

There is an emphatic need for research into development of new cost-effective materials to seal and reseal concrete airfield pavement joints. present methods/materials employed result in inadequate service life of the joints because of material deterioration due to 1) high temperature jet exhaust… More

This proposal will evaluate the use of x-ray computerized tomography (ct) as a viable technique to quantitatively measure fiber concentration, alignment and distribution. three dimensional profiling of fibers will be developed. secondly, indications of quantitatively measuring impact damage has been… More

Calculated ground motion from nuclear explosions predict that at locations near the cavity the rock failure surface will be encountered in extension during later stages of unload. the resulting hoop fractures will produce a failed rock zone surrounding the cavity. high pressure cavity gases could… More

Properties of elastic-brittle materials change under stresses which are high enough to induce microstructural alternations. these microstructural changes ultimately are the causes for macroscale failure of materials. observations and statistical studies of the stress-induced microstructural changes… More

Currently, as reported in program solicitation 90.1 by the air force, the spectrum of bearing and bearing liner materials used in the aircraft bearing systems behave in an unexpected way when subjected to cyclic loadings. to investigate the problem and better predict the fatigue life of this rod and… More

Quantitative verification of the residual in-situ stress field which creates the containment cage is needed to assess the factor of safety against hydraulic fracturing from the cavity wall. phase i will establish the feasiblity of developing a passive stress gauge, absent of active instrumentation,… More

The proposed research program will study soil-pile foundation interaction induced by the detonation of conventional warpons. the ultimate goal of the progrm is to establish a set of general guidelines for foundation design of future strategic structures as well as the assessment of the vulnerability… More

Understanding of the physics of fluid flow through sedimentary rock is fundamental to the petroleum industry. although the transport properties (permeability and connectivity) are directly related to the porosity, complexity arises because they depend critically on the geometry of the pore space.… More

Underground excavation in rock which is subjected to stresses that are a significant fraction of the rock strength can cause failure adjacent to the excavation. recent research on borehole breakouts has shown that a stable breakout is characterized by a stress distribution which is greatly reduced… More

Drill cuttings represent a huge source of valuable data bearing on reservoir quality issues. cuttings are produced during the drilling of every oil and gas well. however, technological innovations are lacking that would allow these materials to be utilized for assessing stoarge and transport… More