注浆裂隙砂质泥岩力学特性和破坏模式研究

Research on Mechanical Properties and Failure Modes of Sandy Mudstone with Grouting Fractures

为研究含注浆裂隙砂质泥岩试件的力学特性和破坏模式,对类岩石材料制作的裂隙试件进行试验。结果表明:①注浆试件应力应变曲线峰后"台阶式"下跌现象不及开放型裂隙试件明显,且已不存在水平延伸式缓慢下跌的现象。②注浆的峰值强度、弹性模量峰值应变最高增长率分别达到36.76%、11.41%、12.71%。③裂隙倾角,裂隙数量越少,注浆效果越好。④单、双裂隙试件,裂隙倾角对试件破坏模式的影响明显;0°倾角,裂隙数量可改变试件破裂模式,随着裂隙数量的增加试件逐渐由主剪切破裂向主拉伸破裂转变。⑤裂隙倾角越接近0°或者90°,裂隙长度越小裂隙面摩擦系数黏聚力越大,裂隙试件最终破坏模式越接近完整岩石试件。

Uniaxial compression tests are conducted for the rock-like specimens with filling fractures in order to investigate the effects of grouting on the mechanical properties and failure modes. Conclusions are drawn as follows:① For the filling specimens,the phenomenon of step down of the post-peak failure stage is alleviated,thus makes the phenomenon of solw decline in horizontal extension no longer exists.② The highest growth rates of the peak strength,elastic modulus and peak strain of the specimens after grouting reached 36.76%,11.41%,and 12.71%,respectively.③ The smaller the crack inclination angle and the fewer the number of cracks,the better the grouting effect.④ Fracture angle has a great effect on the failure modes of single or double fracture specimens;The failure modes can be changed by fracture number under the conditon of 0° fracture angle,with the increase of the fracture number, the specimens gradually changed from main shear failure to main tensile failure.⑤ The closer the crack inclination angle is to 0° or 90°,and the smaller the crack length,the greater the friction coefficient and cohesion of the crack surface,the closer the final failure mode of the grouted crack specimen is to the complete rock specimen.