三峡电站地下厂房岩锚梁温度应力控制措施探讨

以三峡地下电站厂房岩锚梁为研究对象,采用三维有限元数值仿真技术,从岩锚梁混凝土浇筑季节、预应力锚杆加载方式等方面,就如何控制岩锚梁的温度应力进行探讨。认为岩锚梁产生较大温度应力的主要原因是预应力锚杆极大地增加了围岩对岩锚梁的约束作用,限制了梁体的温度变形;为有效降低岩锚梁的温度应力,应尽量安排在低温季节浇筑岩锚梁混凝土,采取分期加载或"卸载—恢复预应力"等温控措施和施工工艺。

Temperature stress control measures for rock anchor beam in the underground powerhouse of the Three Gorges Project

The problem of how to control the temperature stress on a rock anchor beam is analyzed with 3D FEM technology and with consideration of concrete-pouring season,pre-stressed loading means,and other factors,using a rock anchor beam in the underground powerhouse of the Three Gorges Project as an example.The results show that the pre-stressed anchor greatly enhances the constraint and restricts the temperature deformation of the beam.To deduce the temperature stress on the rock anchor beam efficiently,some measures should be taken: the pouring of concrete in a low-temperature season,application of the pre-stress in several stages and use of load-unload-restore pre-stressed technology.