粘滑失稳及其物理场时空分布的实验研究

摩擦滑动的物理场实验研究表明：（１）能量空间分布的差异是失稳的重要条件，单发型大事件常发生于高能量向低能量的突变带或高能量背景区内的相对低能量区；（２）单发型大事件的孕育过程常常经历若干个能量输入输出循环，产生多个前兆阶段，并在失稳前源区常有一个弱化过程。小震或群发型事件失稳前常常只有一个能量积累与强化的过程，失稳前兆阶段性反映较差；（３）粘滑失稳时断层的位错与声发射的大小未见明显关系

EXPERIMENTAL STUDY ON STICK-SLIP INSTABILITY AND EVOLUTION OF ITS PHYSICAL FIELDS

Strain，displacement and AE waveform are observed along a fault in stick－slip experimentswith multi－channel digital sampling system.Some results are discussed in this paper：（1）Moststick－slip events and AE events took place at the same time.（2）There are pre－slip phenomenabefore some single events，No evident relationship between the fault displacement and magnitudeof AE events was found．（3）Inhomogenous spatial distribution of strain energy is an importantcondition for instable slip．Large events often take place in rapid energy change belts or low ener-gy region in high energy background，rather than in the highest energy area. This result can beapplied to outline of the seismic risk regions．（4）Exchange and mutual complement of strain en-ergy between source and adjacent regions are observed．The change of strain energy in source isalways contrary to that in adjacent regions．（5）There is an important difference between largeevents and small events，single events and multiple events．There are s