Experimental studies on fragmentation of rock falls on impact with rock surfaces

Hypervelocity Impact on Rock

Concerted research efforts are being made to find new means of rock disintegration for more rapid, efficient excavation. Water jets, metallic jets and hypervelocity projectiles have been found to cut or break rock with varying degrees of efficiency depending upon several parameters, which are being defined by research in Russia, Britain and the United States. Optimum performance of high velocit...

Experimental Studies of Electrical Fields on a Breaking Rock Sample

When a rock sample is pressed by a force, the pressure on the crystal lattice generates an electrical field around the quart grains due to the piezoelectric effect. If a rock is saturated by conductive fluid, the relative motion between the pore fluid and the matrix solid generates an electromagnetic field due to seismoelectric conversion, and the permeating of fluid into new microcracks made b...

Characterization of Rock Populations on Planetary Surfaces

Characteristics of rock populations on the surfaces of Mars and Venus can be derived from analyses of rock morphology and morphometry data. We present measurements of rock sizes and sphericifies made from Viking lander images using an interactive digital image display system. The rocks considered are in the gravel size range (16-256 mm in diameter). Mean sphericities, form ratios, and roundness...

Land Slides and Rock Falls

Impact of Scale on Rock Strength

The scale dependence of the strength of virtually homogeneous rock is usually considered to be insignificant but the spectrum of discontinuities plays a very important role for the strength of differently sized rock elements and also controls the rock creep strain. Large-scale load tests comprised recording of the creep strain rate that was found to be strongly retarded and negligible for stres...