中文摘要：

在地下开挖工程稳定性分析的数值模拟中,初始地应力模拟的正确与否将会对计算结果的可靠性产生非常重要的影响.初始地应力的模拟主要是通过计算模型边界条件来实现的.对于非均匀的水平地应力,一般是在计算模型的侧面边界上施加非均匀荷载来实现.通过简单模型的模拟试验,发现采用这种应力边界条件对水平地应力的模拟效果与计算模型的几何形状之间有一定的关系：计算模型的宽高比越大,模拟效果越不理想,与实际的地应力状况相差越大.解决这一问题的方法有两种：（1）使计算模型的宽高比尽量等于或小于1;（2）约束计算模型侧面边界的水平位移,在计算域内部给水平地应力直接赋值.

英文摘要：

The validity of numerical simu/ation ot imtial ground stress has very important effect on the dependability of calculated results for the numerical simulation and analysis of stability of underground excavation engineering. The simulation of initial ground stress is realized mainly by boundary conditions of calcu- lation model. As for non - uniform horizontal ground stress, it is realized generally by applying non - uniform pressure load on the lateral boundary/boundaries of the calculation model. However, it is found that there is a certain relationship between simulated result of non - uniform horizontal ground stress and geometrical shape of calculation model： the greater the width to height ratio of the calculation model is, the more unsatisfactory the simulation validity is and the greater the difference between practical ground stress and simulated stress is. At the end of this paper, two methods are given out to solve this problem ： （ 1 ） to decrease the width to height ratio of the calculation model, make it not greater than 1 ; （2） to restrict horizontal displacement of lateral boundary/boundaries and to directly assign ground stress in the field of calculation model,