断层破碎带中的透镜体及透镜体力学效应初步研究

PRELIMINARY FINDINGS ON LENS AND ITS MECHANICAL BEHAVIOR IN THE BROKEN FAULT ZONE

断层破碎带中的透镜体及透镜体力学效应研究在文献中不多见。但是许多断层尤其是扭性断层中的透镜体非常发育,这些透镜体往往控制断层破碎带的强度大小和变形破坏机理,是工程岩体中必须重视的工程地质力学问题。作者经研究认为:(1)透镜体类型多种;(2)透镜体周边一般具断层泥线或泥膜分布;(3)透镜体内具有节理裂隙系统;(4)透镜体周边可以当作结构面或软弱结构面看待;(5)透镜体本身可以作为一个复合结构体看待。在原位力学试验中也揭示了断层泥透镜体在原位剪切试验和单轴压缩试验中的若干力学行为,其表现是:(1)透镜体周边具有结构面力学效应;(2)断层泥透镜体控制着强度大小、变形破坏机理。

There may not be many reports available in the literature about the lens and its mechanical behavior in broken fault zone. Lens bodies are usually well developed in the sheared faults. The intensity and the deformed or broken mechanism of the broken fault zones are normally under the control of the lens bodies. Their engineering geological mechanism should be emphasized and examined in detail. This paper presents a case study on the lens and its mechanical behavior in a broken fualt zone. The findings of the study can be summarzied as follows ： （ 1） There are various types of the lens bodies;（2） the fault lines and the mud membranes are usually distributed along the periphery of the lens body ; （ 3 ） There are systems of joint cracks in the lens bodies ; （ 4 ） The periphery of a lens body can be regarded as the structural surface or weak structural surface ; The lens body itself can be seen as a compound structure. Many mechanical behaviors of the lens body of the fault mud in the experiments of the original - location cutting and the single - axle compression are also revealed in the experiment of the original - location mechanics ： （ 1 ） the periphery of the lens body has the mechanical effect of the structural surface ; （ 2 ） the lens body controls the intensity and the deformed or broken mechanism.