侧限条件对岩石单轴压缩性能的影响分析

为研究侧限条件对岩石单轴压缩性能的影响规律,借助FLAC3D有限差分软件对位移控制和应力控制两种加载模式下的大理岩试样实施了数值模拟试验。试验实施过程中将侧限条件分为无侧限、单面侧限、邻面侧限、对面侧限、三面侧限和完全(四面)侧限六种工况,试验结果显示:位移控制模式和应力控制模式对岩石单轴压缩性能存在显著区别,两种加载控制模式下岩样的竖向位移均在竖向应力达到相同数值后出现增长速率分离,但前者使试样出现显著的蠕变现象;不同侧限工况下,临空面Y向离面位移的发展可划分为近似线性低速发展和非线性高速发展两个阶段,在位移控制模式下三面侧限条件对应的后期位移发展更为剧烈;最大剪切应变率计算云图显示部分侧限条件下远离侧限面的试样角点优先破坏,但最大剪切应变率数值与侧限数量并非呈线性关系。研究结论对更为精准的确定复杂应力条件下岩土体的强度和形变特征具有一定的参考意义。

Impact Analysis of Confining Conditions on the Properties of Rock Uner Uniaxial Compression

In order to investigate the effect of confining conditions on the properties of rock under uniaxial compression, in this paper, by means of FLAC3D finite difference software to control the displacement and stress control marble specimens under two loading modes to numerical simulation test. Test implementation process will be divided into unconfined confining conditions, single side limit, adjacent surface side, opposite side limit, limit on three sides by confining and completely confining condition, test results show that the displacement control mode and stress control mode for rock under uniaxial compression performance, there were significant difference between two kinds of load control mode sample vertical displacement are in vertical stress reaches the same numerical growth rate after separation, but the former made significant sample of creep phenomenon; Different confining conditions, the development of the airport surface Y from the surface displacement can be divided into two approximate linear speed and nonlinear high-speed development stage, in the displacement control mode on three sides by confining conditions corresponding to the displacement of the late development of more severe; Maximum shear strain rate calculation chart shows part of the confining conditions from the sample corner priority disruption of confining, but the number of maximum shear strain rate values and confining is not a linear relationship. This article research conclusion to a more precise determination of complex stress conditions of rock mass strength and deformation characteristics has certain reference significance.