含预制裂纹大理岩的压剪试验分析  

Experimental research on pre-existing cracks in marble under compression

作　　者：李银平[1] 王元汉[2] 陈龙珠[1] 余飞[2] 李亮辉[2] 

机构地区：[1]上海交通大学建筑工程与力学学院 [2]华中科技大学土木工程与力学学院,湖北武汉430074

出　　处：《岩土工程学报》2004年第1期120-124,共5页Chinese Journal of Geotechnical Engineering

基　　金：中国科学院武汉岩土力学研究所岩土力学重点试验室开放基金项目(Z110305);华中科技大学优秀博士论文基金项目

摘　　要：采用含预制裂纹大理岩块试件对单轴压缩荷载作用下的裂纹扩展及裂纹搭接进行试验研究。试验表明含预制裂纹试件的临界失稳荷载、破坏时的应变及弹性模量都明显降低,原生裂纹的方位对产生何种裂隙有显著的影响,岩桥区尺寸对翼裂的萌生和扩展有显著的影响,使试件表现出完全不同的破坏方式。试验中观察到预制裂纹尖端萌生的裂纹有张拉型的翼形裂纹、压剪型的二次裂纹和翼裂反向裂纹等多种形态。试验观测还表明大理岩翼形裂纹的起裂角为52°～68°之间,而模型材料试验的结果为77°左右,这表明模型材料并不能完全模拟真实岩体的特性。An experimental approach on propagation and coalescence of pre-existing cracks in marble samples under compression is carried out. It is shown that the influence of pre-existing cracks is significant,and the critical collapsing load, failure stress and elastic modulus are all reduced. Many forms of wing cracks initiated from the tips of pre-existing cracks are observed, for example, tension mode wing crack, shear mode wing crack and reversed wing crack. The orientations of pre-existing cracks can decide which kind of wing cracks will be produced. The interactions between cracks are of marked influence on the initiation and propagation of wing cracks, and make failure manners of samples thoroughly different. The initial angles of wing cracks in marble range between 52°～68°, which are lower than the results (about 77°) of previous experiments on model materials. This indicates that the model materials cannot simulate fully the characters of the real rock materials.

关 键 词：单轴压缩 贯通 压剪试验 大理岩 二次裂纹 弹性模量 

分 类 号：TU458.3[建筑科学—岩土工程]