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黄土中裂隙属黄土体结构面,影响黄土的强度特性,对工程的稳定和安全产生重要影响。以临潼地区Q2黄土为研究对象,开展了裂隙性黄土无侧限抗压强度试验,探讨了不同裂隙倾角对裂隙性黄土强度特性的影响规律。试验结果表明:单轴受压条件下,不同裂隙倾角的裂隙性黄土破坏模式主要有压裂破坏、压剪破坏和滑移-压剪复合破坏三种类型,且裂隙性黄土试样破裂面的形成受裂隙倾角的控制。裂隙倾角变化对裂隙性黄土的应力-应变曲线影响显著,裂隙倾角为0°~30°和90°时,裂隙性黄土的应力-应变曲线可分为裂隙压密阶段、弹性变形阶段、塑性屈服阶段以及残余阶段等;而裂隙倾角为40°~70°,裂隙性黄土的应力-应变曲线无明显的4个阶段,且破坏是突发性的。随裂隙倾角的增大,裂隙性黄土单轴抗压强度曲线整体表现为先降低后增大的“V”形。显著体现裂隙倾角变化对裂隙性黄土试样单轴抗压强度的影响,同时,裂隙倾角对裂隙性黄土抗剪强度也具有显著的控制效应。
Loess cracks in the loess structure is the surface, affecting the strength characteristics of loess, the stability and safety of the project have a significant impact. Taking Q2 loess in Lintong area as the research object, unconfined compressive strength tests of fissured loess were carried out. The influence of different fissure dip angles on the strength characteristics of fissured loess was discussed. The results show that under the condition of uniaxial compression, the failure modes of fractured loess with different fracture inclination mainly include three types of fracturing failure, pressure-shear failure and slip-pressure-shear composite failure, and the fracture surface of the cracked loess specimen Formation of cracks controlled by inclination. The stress-strain curves of fissured loess are significantly influenced by the change of fissure inclination. When the fissure inclination is 0 ° -30 ° and 90 °, the stress-strain curves of fissured loess can be divided into crevice compacting stage, elastic deformation stage, plastic yielding Stage and residual stage, etc .; while the fracture angle is 40 ° ~ 70 °, the stress-strain curve of fractured loess has no obvious four stages and the failure is abrupt. With the increase of fracture angle, the uniaxial compressive strength curve of fractured loess shows the shape of “V” which first decreases and then increases. It shows the influence of the change of fracture inclination on the uniaxial compressive strength of fissured loess specimens. Meanwhile, the fissure angle also has significant control effect on the shear strength of fissured loess.