摘要
采用非线性有限元方法研究了钢筋混凝土岩锚吊车梁和围岩的力学特性。结合某水电站三期扩建工程实践,假定地下厂房围岩和混凝土材料满足Drucker-Prager弹塑性本构关系,采用三维有限元方法计算模拟了岩锚吊车梁的破坏机制,并进行了相应的稳定性分析。数值模拟结果表明,地下厂房围岩与岩锚吊车梁交界面的粘聚力和摩擦系数大小对岩锚吊车梁的稳定性有着重要的影响。随着围岩与混凝土岩锚吊车梁粘聚力的降低,岩锚吊车梁的抗滑安全系数减小。而当围岩与岩锚梁交界面出现破坏时,岩锚吊车梁的安全系数为3.7。地下厂房的继续开挖对于吊车梁系统锚杆和周围岩体的应力分布有较大影响。有效控制地下厂房爆破开挖对围岩的损伤,对于改善岩锚吊车梁的受力状态和提高吊车梁的稳定性具有实际意义。
The mechanical behavior of reinforced concrete crane girder bolted to rock wall of chamber is analyzed with nonlinear finite element method. The concrete and rock mass are modeled by Drucker-Prager elasto-perfectly plastic constitutive relation. The Drocker-Prager yield criterion has found wide practical application as a method of defining the stress conditions under which rock mass will deform inelastically and collapse. Combined with the extending project practice of underground powerhouse at hydropower stations,the fracturing mechanism and stability of crane girder are investigated numerically. Computational results show that the cohesion and friction angle between rock mass and concrete have a notable influence on the stability of crane girder bolted to rock wall of chamber. The safety factor of concrete crane girder will be reduced with the decrement of inner cohesion between the rock mass and concrete crane girder. The safety factor of concrete crane girder can exceed 3.7 while the failure of interface between the rock mass and concrete occures. The further excavation of underground powerhouse will affect the stress distribution of system bolts and rock mass near crane girder. It is very important for improving stress states and enhancing stability of concrete crane girder to control effectively rock damages induced by excavation blasting.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2004年第10期1730-1734,共5页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金(10072014)资助项目
