Pulsed water jets, generated by cumulative nozzle devices, have a pressure-time behavior which can cause rock to fail by three distinct modes: mechanical crushing, hydraulic erosion and large-scale propagation of fluid pressurized cracks. the interactions between these three modes of failure can be… More

The commercial application of small charge, continuous drilland blast and systems has not been realized primarily because of the hazards and operational problems deriving from the (albeit smaller) explosive charges employed. considerable recent work on rock fragmentation by controlledfracture… More

Electromagnetic gage techniques are ideally suited to measuring the dynamic tensile fracture of a broad variety ofmaterials. as electromagnetic sensing elements can be constructed of any conducting material and are not affected by micro-deformation they can be readily embedded in ceramics, plastics,… More

Most efforts to increase production from unconventional gas resources in the united states require some form of wellboreor formation fracturing to increase the flow of gas to the wells. both explosive and hydraulic fracturing techniques have been used with success in the stimulation of… More

Data on the response of materials and structures to nuclear weapons is critical to the improved design of weapons and defense systems. much of this data is obtained in high explosive simulation (hes) tests. for both hes and nuclear tests, instrumentation to obtain the requisite data must be able to… More

In support of existing and proposed nuclear testlimitation treaties, it is increasingly important that improved methods for understanding and predicting the seismic coupling of nuclear detonations be developed. with the possibility of better define the geology existing at soviet test sites, subtle… More