大型地下洞室群开挖支护弹塑性损伤优化研究

正在设计施工的某大型水电站地下洞室群地质条件复杂，其开挖支护方案对围岩稳定性非常重要，因此，对支护方案进行优化研究非常必要。为更真实地模拟岩体的力学特性，研究施工过程中岩体的损伤破坏，根据不可逆热力学理论建立了弹塑性损伤模型和损伤演化方程，并编制了三维弹塑性损伤有限元程序D-FEM，具有模拟开挖与支护、计算速度快、群组功能等特点。建立大型地下洞室群三维数值模型，将通过实测地应力反演的应力作为初始地应力。采用D-FEM模拟了不同支护方案洞室群的施工过程，通过分析洞室围岩的应力、位移和破损区，支护方案2的支护效果最好，建议采用此方案。考虑岩体损伤演化后与FLAC3D塑性区相比，洞室群边墙中部的破损区显著增加，因此，程序可应用于地下工程的稳定性分析

Study of support optimization of large underground cavern group excavation using elastoplastic damage finite elements

The geological conditions of large underground cavern group are complicated,of which the support project affects stability of surrounding rock.So it is important to study the support optimization of large underground cavern group excavation.In order to simulate rock mass veritably and analyze its damage in construction,the elastoplastic damage model and damage evolution equation are presented on the basis of the irreversible thermodynamics theory.The 3D elastoplastic damage finite element code D-FEM is prog...