摘要
在大型地下岩体的开挖过程中，经常会出现三维不稳定块体。这对建筑的安全是一个重大的隐患。三维建模是采用刚体极限平衡理论评估块体稳定性的基础．利用AutoCAD软件的三维建模功能．通过现场地质编录资料，快速直观地建立块体的三维模型．应用AutoCAD三维绘图的坐标变换功能，对空间力系进行投影，求出块体的总抗滑力和总下滑力，并采用刚体极限平衡理论评估块体稳定性。
In large underground excavation project, there are some instable blocks in great danger. They are a major security threat to the architecture. Three-dimensional modeling is the base of stability evaluation by ultimate equilibrium. Basing on the geological data, the three-dimensional model of the block is directly established by using the triaxial modeling function in AUTOCAD. Then project the triaxial forces using the function of coordinate transformation in AUTOCAD, and the total anti- sliding force and sliding force can be gained. Finally, the stability of the block can be evaluated by ultimate equilibrium.
