重复剪切作用下充填物对结构面力学性质的影响

发布时间：2019-03-14 15:34

【摘要】：目前,对于结构面的研究主要包括对剪切曲线形态的描述及结构面粗糙度、组数、充填物等因素对结构面强度参数的影响,一般情况下,这类研究的基础是结构面经受静荷载的作用。实际上,结构面也很容易遭受地震、水位升降、爆破等动力荷载的反复剪切作用,但是,至今对反复剪切作用下结构面力学特性的研究较少或缺乏系统性。笔者在室内直剪试验的基础上,研究了重复剪切作用下充填物对结构面变形和强度的影响。采用钢制模具和混凝土材料预制4种起伏角度结构面,在1.56MPa法向应力和两种充填状态下进行多次直剪试验,分析每次剪切过程中的切向应力和法向位移随切向位移的变化。通过对切向应力和法向位移随切向位移变化曲线分析可知,初次剪切时,起伏角度越大,结构面剪切破坏方式容易从滑移破坏过渡为剪断破坏;第二次剪切开始,无论起伏角度如何,结构面的剪切破坏方式基本上都转变为滑移破坏;充填物的存在基本不会改变结构面的剪切破坏方式,但会使剪切过程中结构面的爬坡效应增强,使结构面被剪断或磨损的作用减弱,峰值法向位移增大。
[Abstract]:At present, the research of the structural plane mainly includes the description of the shape of the shear curve and the influence of the roughness of the structural plane, the number of components, the filling and other factors on the strength parameters of the structural plane. This kind of research is based on the static load on the structural surface. In fact, the structural plane is also vulnerable to repeated shear effects of dynamic loads, such as earthquake, water level rise and fall, blasting and so on. However, there is little or no systematic study on the mechanical properties of the structural plane under the repeated shear action. Based on the laboratory direct shear test, the influence of the filling material on the deformation and strength of the structural surface under repeated shear is studied. A series of direct shear tests were carried out under 1.56MPa normal stress and two filling states by prefabricating four kinds of undulating angle structural planes of steel dies and concrete materials. The variation of tangential stress and normal displacement with tangential displacement during each shear process was analyzed. By analyzing the curves of shear stress and normal displacement with tangential displacement, it can be seen that the larger the fluctuation angle is, the more easily the shear failure mode of the structural plane changes from slip failure to shear failure. At the beginning of the second shear, regardless of the fluctuation angle, the shear failure mode of the structural surface is basically transformed into slip failure. The existence of the filling will not change the shear failure mode of the structural surface, but will enhance the climbing effect of the structural surface during the shear process, weaken the effect of shear or wear on the structural surface, and increase the displacement of the peak value method.
【作者单位】：河海大学地球科学与工程学院;四川志德岩土工程有限责任公司;
【基金】：国家自然科学基金项目(41102162,41672258)资助
【分类号】：TU45

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