地下洞室群围岩稳定性分析及其结果的可视化

STABILITY ANALYSIS OF SURROUNDING ROCK OF UNDERGROUND EXCAVATIONS AND VISUALIZATION OF ITS RESULTS

大型地下洞室群的稳定性是地下水电站面临的一个关键问题,三维非线性有限元方法常常用于评价地下洞室群的稳定性。介绍了有限元方法用于评价地下洞室群稳定性的基本方法,包括岩体本构模型的选择、非线性迭代方法、围岩失效准则、围岩稳定性评价指标以及锚杆和锚索等支护结构的模拟方法。为了实现计算结果的可视化,基于面向对象思想开发用于地下洞室群围岩稳定性分析的可视化软件系统。该软件能够方便绘制各物理量的空间等值线和空间矢量图形,并能显示结构变形以及失效破坏区的分布。除此之外,该软件还可以显示包括锚杆和锚索在内的锚固结构的空间图形和应力情况。最后,采用提出的计算方法和开发的可视化软件进行了工程实例分析。结果显示,提出的计算方法是合理有效的,所开发的可视化软件在计算结果的评价方面显示强大的功能。

The stability of large-scale excavations always is a key problem in underground water power stations. In order to evaluate the stability of these excavations, the three-dimensional nonlinear finite element method is used usually. The basic ideas about how to use finite element method in stability analysis of underground excavations are introduced, including the choice of constitutive relation of rock mass, iterative method of nonlinear computation, failure criterion of surrounding rock, optimal ways of stability evaluation and simulation methods of anchorage supporting structure. To realize the visualization of results of computation, visualization software of underground excavations＇ finite element analysis is developed based on the object-oriented idea. This software can draw conveniently spatial contours and vector diagram of every physical quantity and display structure＇s deformation and the distribution condition of failure area. Besides, the software can also show anchorage structure including anchor rod and anchorage cable and its stress. At last, above calculation methods and visualization software are used in an engineering example. The results show that the calculation methods presented above are rational and effective; and the visualization software is powerful in evaluation of computation results.