愈合断层再破裂的实验研究

AN EXPERIMENTAL STUDY OF REFRACTURE ON HEALED FAULT

摘要:

将济南辉长岩岩柱沿不同角度锯开,再用环氧树脂粘接后加工成标准园柱形样品以模拟愈合断层。将样品置放在单轴压机下加压,使愈合断层再破裂。实验表明:愈合断层再破裂的前兆变形、破裂前的声发射率变化规律和声发射b值变化规律在某些条件下类似于完整岩石的破裂,而在某些条件下又类似于既存断层的错动。断层面与主压应力的交角以及断层愈合程度是影响愈合断层再破裂的前兆特征的主要因素。本文还指出,在地震活动性的研究中,地震断层在一定程度上愈合后再发生破裂这一问题是不容忽视的重要问题。

Abstract:

In order to model healed fault,standard columnar sample is made from Jinan gabbro,which is sawed with various angles and cemented by epoxy resin.Under the uniaxial stress,healed fault is refractured.It is found that precursor deformation of healed fault,which is refractured,the regular change of acoustic ratio and the bvalue before rupture are similar to the complete samplin some conditions and to the stagger of original faults in sample in other conditions.The angle between fault plane and main stress as well as the degree of fault being healed,is the factor affecting the refrac ture of healed fault.It shows that the problem of healed faults is very important in study of seismic activity.