不同尺度石灰岩柱单轴压缩试验研究

Uniaxial Compression Experiment Study on Lime Rock Specimen with Different Size

岩石具有尺度效应,因此研究不同几何尺度的岩石力学特性规律是很有意义的。选取河北省井陉石材厂均匀致密的石灰岩,加工成不同长度、横断面为25 mm×25 mm的方形岩柱,并进行单轴压缩试验,得出了一些有益规律:(1)长细比越小,岩柱抵抗动载的性能越好;(2)岩柱的弹性模量和极限变形模量与长细比密切相关,随长细比的增加呈对数增加;(3)岩柱平均极限轴向应变随长细比的增加呈幂函数减小,长细比为2时,岩柱平均极限轴向应变急剧减小,长细比在3以后,平均极限轴向应变几乎不变。

The lime rock was taken from Jingxing rock machining factory in Hebei province and processed to quadrate blocks with same transect （25 mm × 25mm） but different length （15,50, 75,100,150,175,200 mm）. The uniaxial compression experiments have been conducted with these samples and several useful rules have been achieved： （ 1 ） the less slenderness ratio, the better the performance of rock resisting dynamic load; （2） both elastic module and utmost deformation module has close correlation with slenderness ratio, which increase in logarithm as slenderness ratio increases; （3） the average utmost axial strain decreases in power as slenderness ratio increases. It decreases sharply when the slenderness is 2 and keeps invariable almost when the slenderness is more than 3.