赣南花岗岩风化带岩土体强度特征及边坡破坏模式分析

为研究赣南地区花岗岩风化带岩土体强度特性及边坡破坏模式,采用室内岩矿鉴定、X粉晶衍射试验和电镜扫描等方法对原岩和全风化花岗岩进行矿物成分和微观结构分析,同时通过全风化花岗岩三轴固结不排水剪切试验,中风化花岗岩单轴和三轴试验对风化带岩土体的强度特征和破坏模式进行了研究。结果表明:随着围压增大,全风化花岗岩应力-应变关系发生了转型,破坏模式为先鼓胀再剪切破坏;中风化花岗岩在单轴压缩条件下经历了四个破坏阶段,三轴试验得到岩块的抗剪强度参数,经虎克布朗准则反演得到了岩体的强度参数。结合野外特征,赣南花岗岩风化带岩土体边坡失稳破坏模式主要有5种,其中坡面冲刷破坏占比较大。

Strength characteristics of granite weathering zone and analysis of slope failure mode in south Jiangxi Province

In order to study the strength characteristics of granite weathering zone and the slope failure mode in south Jiangxi, the indoor rock mineral identification, X-ray powder diffraction and scanning electron microscopy were used to analysis mineral composition and microstructure of the granite and completely weathered. And through the uniaxial consolidation undrained shear test of completely weathered granite, the uniaxial and triaxial tests of moderately weathered granite, the strength and failure mode of weathered zone were studied. The results show that with the increase of confining pressure, the stress-strain relationship of completely weathered granite has transformed, which shows swelling and shear failure. The granite undergoes four failure stages under uniaxial test, the shear strength parameters of rocks are obtained by triaxial test, then the strength parameters of rock mass are obtained by Hooke Brown criterion inversion. With field investigation, there are five main failure modes of granite weathering slope in south Jiangxi, among which scouring failure accounts for a large proportion.