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上限原理有限元法不仅可以得到边坡的安全系数,还可以给出临界滑动面,且摆脱了极限平衡法假设条件过多、过于刚性的缺点,具有更严谨的理论基础,因此拥有更广阔的应用前景。但是,对于岩质边坡,由于其存在大量的节理面,造成应力不连续,这给直接运用传统的数值计算方法带来了困难。其实,每组的节理面均表示在某一特定的方位上边坡的材料特性比较差,只需在处理这些特定方位时,采用相应的软弱节理面的材料特征即可,这样便可有效地化解节理面难以模拟的缺陷。因此,基于传统的上限有限元法,采用四边形单元,通过对单元建立积分意义上的协调方程的弱形式,来得到可以调整单元内部速度场的线性化的协调方程,从而可以克服插值速度场为非线性的缺点。对于任意应力点,从空间方位出发,将方位进行离散,建立并推导出了基于方位离散线性化的上限有限元法,该方法在考虑含多组节理面的岩质边坡计算上有着更好的优势。两个算例结果表明:该方法与传统的上限有限元法一样,可以稳定地从极限解的上方收敛,满足上限性质,且对于含多组节理面的岩质边坡同样有很好的收敛性。
The principle of upper bound finite element method not only can get the safety factor of slope, but also can give the critical sliding surface, and get rid of the limit equilibrium method, the assumption is too much, too rigid shortcomings, with more rigorous theoretical basis, so have a broader Application prospects. However, for rock slopes, because of the existence of a large number of joints, the stress discontinuities make it difficult to apply the traditional numerical methods directly. In fact, the joint surfaces of each group indicate that the material properties of the slope are relatively poor in a particular orientation, and the material characteristics of the corresponding soft jointed surfaces can be used only when dealing with these specific orientations, which can be effectively resolved Joint surface difficult to simulate the defect. Therefore, based on the traditional upper bound finite element method, a quadrilateral element is used to establish a linearized coordination equation that can adjust the velocity field inside the element by establishing a weak form of the coordination equation in the sense of integral, so that the interpolation velocity field can be overcome Non-linear shortcomings. For any stress point, based on the spatial orientation, the azimuths are discretized, and the upper bound finite element method based on discrete linearization of azimuth is established and deduced. This method is better in considering the calculation of rock slopes with multiple sets of joint surfaces The advantages. The results of two examples show that the proposed method can converge steadily from above the limit solution and satisfy the upper limit property, as well as the traditional upper bound finite element method, and also has good convergence for rock slopes with multiple sets of joint surfaces Sex.