基于尺度效应的灰岩强度研究

The study of size effect on the limestone strength

通过水口山康家湾矿采集的岩样,利用岩石力学试验机对不同直径和不同高度的灰岩进行了大量的单轴压缩试验,研究了不同高径比岩样的变形和破坏形式。结果表明:岩石高度对岩石强度峰值以前的变形特性没有显著的影响;当直径一定时,随着长度的增大,岩样的破裂形式由复杂的平行破坏变为剪切破坏。同时指出通过增加垫块的刚度可以减小端面的摩擦效应。同时对由于取样造成的岩样强度降低的原因进行了分析。

Through the collected rock samples from Kangjiawan mining of Shuikoushan, the author carried out plenty of uniaxial compressed experiments on limestone with different diameter and height by rock mechanics testing machine, and discussed the deformation and damage form of the limestone samples with different ratio of height to diameter. The result shows： that the height of rock has no notable effect on the deformation characteristics before the peak value of the rock strength. When the diameter is ceaain, with the increase of length, the breaking form of the rock samples will change from complex parallelled damage to sheared damage. At the same time, by increasing the chock rigidity the friction effect can be reduced. Then the reason that the strength of the rock samples is reduced because of sampling is analysed.