含显著沉积弱面砂岩加卸荷破坏试验研究  

EXPERIMENTAL STUDY ON THE FAILURE OF SANDSTONE WITH NOTABLE BEDDING UNDER LOADING AND UNLOADING

作　　者：王乐华[1] 陈星[2] 党莉[1] 

机构地区：[1]三峡大学三峡库区地质灾害教育部重点实验室,宜昌443002 [2]中国长江三峡集团公司枢纽管理局,宜昌443002

出　　处：《工程力学》2013年第5期181-187,共7页Engineering Mechanics

基　　金：国家自然科学基金项目(50909052);教育部重点项目(212114)

摘　　要：层状岩体加卸荷条件下的各向异性规律对于指导工程设计、施工具有重要意义。对含显著沉积弱面的水平、垂直层理的宜昌砂岩加载、卸载破坏的试验研究表明:1)水平、垂直层理砂岩回弹值、纵波波速与强度存在一定的相关性,其基本规律是回弹值或者纵波波速越大,岩体强度越大;2)无论采用加载还是卸载破坏方式,相同围压下,垂直层理岩体的强度一般大于水平层理岩体;3)无论是水平还是垂直层理岩体,卸荷破坏峰值强度在低围压下高于加载破坏强度,而高围压下低于加载破坏强度;4)该文试验条件下,加卸载破坏形式主要是剪切破坏,根据Mohr-Coulomb准则预测的破坏角和实测值非常接近,水平和垂直层理岩体加卸载破坏的破裂面并未受到沉积弱面的影响。The anisotropy rules of stratified rock under loading or unloading are significant to guide the engineering design and construction. The research results on the failure of sandstones with notable horizontal or vertical bedding in Yiehang shows that： 1） there is a certain correlation between the rebounding data, longitudinal wave velocity and strength of rock. The basic law is that the larger the rebounding data or longitudinal wave velocity, the higher the strength of the rock. 2） No matter in the failure mode of loading or unloading, the strength of the sandstones with vertical bedding is normally higher than that with horizontal bedding under the same confining pressure. 3） No matter the sandstones with horizontal or vertical bedding, under low confining pressure, the unloading failure peak strength of which is higher than that under loading condition, but under high confining pressure, the phenomenon is opposite. 4） The loading and unloading failure modes of the sandstone are mainly shear failure. The predicted values of failure angle of the sandstone specimens according to Molar-Coulomb criterion are very close to the measured values. The fracture surface of the sandstone specimens with horizontal or vertical bedding are not affected by the bedding.

关 键 词：沉积弱面 砂岩 卸荷 回弹值 纵波波速 强度 

分 类 号：TU45[建筑科学—岩土工程]