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断层广泛存在于岩体中,对于含有断层的岩体来讲,其在地震或各类开挖影响下的破坏往往是沿着断层面发生的,其中,断层面的粗糙性质对岩体破坏具有很大的影响。在现场勘测并研究检验实地断层面具有分形性质的基础上,用数值模拟方法研究了含分形断层面岩体破坏过程的应力响应、应力场、变形场和破坏机理。利用Weaerstrass-Mandelbrot函数构造分形维数D分别为1.1,1.2,1.3,1.4,1.5的5条自仿射分形曲线,并构造于数值模拟模型中,实施开挖引起岩体沿断层面破坏的数值模拟。用大型通用有限元分析(FEA)软件——ANSYS进行了模拟分析,并与含平面断层岩体的滑移破坏情况进行了对比分析。模拟分析表明,断层存在对岩体中的应力分布和变形分布有着强烈的阻隔作用,而且断层面分形维数越小,这种阻隔作用就越强烈,断层面的分形维数D=1.5时的应力分布和变形分布较D=1.1,1.2,1.3,1.4时更为接近无断层时的情况;随着断层面分形维数的增加,断层上盘(破坏或移动盘)对下盘的带动作用越来越大,断层面的分形维数D=1.1时的断层两侧岩体滑移落差值最接近于平面断层时的情况,断层露头处的台阶落差也最大,这与工程实际吻合。
Faults exist widely in rock masses. For the fault-bearing rock mass, the failure of the fault-bearing rock mass usually occurs along the fault plane under the influence of earthquakes or various types of excavations. The roughness of the fault plane has the effect on the failure of the rock mass Great impact. On the basis of field survey and research on the fractal properties of the fault plane, the stress response, stress field, deformation field and failure mechanism of the fractured rock mass with fractured fault surface are studied by numerical simulation. Five self-affine fractal curves with fractal dimension D of 1.1, 1.2, 1.3, 1.4 and 1.5 were constructed by Weaerstrass-Mandelbrot function and constructed in numerical simulation model. The numerical values of the failure of rock mass along fault plane simulation. A large general finite element analysis (FEA) software, ANSYS, was used to simulate and analyze the slip damage of rock mass with plane fault. The simulation results show that the presence of faults has a strong barrier to the stress distribution and deformation distribution in the rock mass. The smaller the fractal dimension of the fault plane, the stronger the barrier function. When the fractal dimension of the fault plane is D = 1.5 The distribution of stress and deformation are more similar to the case of no fault at D = 1.1, 1.2, 1.3 and 1.4. With the increase of the fractal dimension of the fault plane, the driving force of the upper plate (damage or moving plate) More and more. When the fractal dimension of fractured face D = 1.1, the difference between the slip of rock masses on both sides of the fault is the closest to that of the plane fault, and the step difference of the outcrop of the fault is also the largest, which agrees well with the engineering practice.