基于三维地质模型的地下洞室群地震动力响应分析

工程区域地质条件是影响地下洞室群稳定的重要因素，而通用数值分析软件在建立复杂地质模型时存在建模时间长、准确度低、不能真实反映复杂地质特征等困难。针对此问题，采用以非均匀有理B样条（NURBS)为主的混合数据结构，对复杂区域地质构造进行了三维建模，建立了西南某水电站大型地下洞室群的三维地质模型。并以此模型为基础，建立了包括空间曲面断层、地层等复杂地质因素的数值模型，结合ABAQUS的隐式和显式分析，对洞室开挖和地震作用下的动力时程响应进行了仿真分析。分析结果表明，该方法不仅较大程度地反映了实际地质情况，而且有利于数值仿真分析的网格剖分与计算，从而为分析地下洞室群地震反应提供了三维数值模型，为地震作用下洞室的安全性评价提供了重要的技术支持。

Dynamic response analysis of underground cavern group based on 3D geologic model

Engineering regional geologic condition is an important factor that affects the stabilization of underground cavern group,while the common numerical analysis soft wares have some disadvantages such as the long time consumption for modeling,low accuracy and the difficulty in reflecting the real complex geological features.Aiming at these problems,a mixed data structure,in which nonuniform rational B-spline(NURBS) is predominated,is used to carry out the 3D detailed modeling of the complex regional geological structure;and the whole 3D refined geological model of a large underground cavern group in Southwest China is established by this method.Based on this geological model,a numerical model including complex geological factors such as the space surface faults,formations have also been built;and combine the implicit and explicit module of ABAQUS,the underground cavern group excavation and dynamic response under seismic load have been simulated.The results indicate that: This approach not only reflects the actual geological condition to the greatest degree,but also makes against the mesh generation and numerical calculation;thus it provides an accurate and practical model for the dynamic response analysis of underground cavern group and important technical support for the seismic safety evaluation of underground cavern group.