现场大尺度摩擦实验中观测到的断层泥中的塑性变形波

本文介绍了在断层区的岩体中进行的现场大尺度摩擦实验。实验的目的是探索地壳中变形波的存在。实验结果表明,在加载时断层泥屈服时间不一致,加载一端的断层泥先屈服,然后屈服范围逐步扩大,此过程相应于塑性变形波在断层泥中的传播。实验测得试件中塑性变形波波速约为2—3 cm/min,实际相当于10—16km/year。

THE PLASTIC DEFORMATION WAVE OBSERVED IN FAULT GOUGE IN FIELD TESTS OF LARGE SCALE SAMPLES

Recently some scholars think that in the crust the stress probably causes slow plastic deformation wave, and consider that this deformation wave is significant in process of earthquake pregnancy, However, it is difficult to observe this deformation wave both in nature and in laboratory. We proceeded some field tests of large Scale samples to explore the existence of this wave. The tests were proceeded in rock body of fault zone. The test bodies of which size is 50×60×30cm⁸, were made in tunnels, The frictional surface is layer of nature fault gouge. The tests show that during loading the yield time of gouge is not identical. The gouge near the loading end yields first, then the yield scope expands progressively. This process corresponds with the propagation of plastic deformation wave in fault gouge. The measured velocity of plastic deformation wave is about 2-3cm/min, it corresponds to 10-16km/year.