郑颖人 院士 演讲PPT茅以升和国际会议 有限元极限分析法在隧道稳定分析中应用.pptVIP

The application of FEM limit analysis in the stability analysis of tunnels有限元极限分析法在隧道稳定分析中的应用;;Principles of FEM limit analysis 有限元极限分析法原理（用数值计算求极限分析）; 1975, Zienkiewicz put forward FEM strength reduction.;Traditional failure mechanism of tunnels （传统的隧道破坏机理）;Modern failure mechanism of tunnels （现代的隧洞破坏机理）;Crack surface of deep-buried tunnels （深埋隧洞的破裂面）;;Analysis on the comparison of model tests and numerical simulation（模型试验和数值模拟的对比分析） ; Results of model tests and numerical simulations （模型试验的数值模拟和试验结果的对比分析） 极限荷载 最大距离;Identification of the location of crack surface of deep-buried tunnels（深埋隧洞破裂面位置的确定方法）;Failure state of homogeneous tunnels （均质隧洞的破坏状态）;Monitoring of failure of deep-buried tunnels（深埋隧洞破坏的现场监测）;Crack surface shallow-buried tunnels（浅埋隧洞的破裂面在拱顶）;Failure process and divide between shallow- and deep-bury of different buried depth（不同埋深隧洞的破坏过程与深浅埋分界线）;With the increase of buried depth, Pressure arch of shallow-bury forms gradually.（形成浅埋压力拱）;;Failure mechanism of rectangle tunnel （矩形隧洞的破坏机理） ;? Collapsed balance arch forms after the lateral failure. 破坏后形成平衡拱;Failure process of joint tunnel;Joint of 45 o;Safety factors of tunnel under different joint angles （不同节理倾角时隧洞的安全系数）;Problems existing in present tunnel design（现行隧洞设计存在的问题）;Problem Ⅰ ;Elastic modulus has great influence on the displacement;Problem Ⅱ ;以安全系数为围岩稳定标准的优点 Adopting the safety factor of surrounding rock as standards: ★ It has strict mechanic basis. 有严格的力学基础 ★ Stability has unique standards. 稳定有统一标准 ★ It would not be affected by deformation parameters of rock and soil. 不受岩土参数影响;Calculation of shear safety factor of loess tunnels（黄土隧洞剪切安全系数的计算）;? Calculation examples dwelling carven （居民洞室） ? Engineering conditions ? Loess tunnel without lining: the span is 3m; the side wall is 1.5m high and buried-depth is 30m. ? Arch height are 0.0, 0.5, 1.0, 1.5 and 2.0m. ? Mechanical and physic