龙滩碾压混凝土重力坝水平层面稳定安全的断裂分析

提出了一种适用于分析含压剪裂缝结构的非线性断裂力学数值分析模型——压剪钝裂缝带模型；并基于此模型，提出了一种新的求解方法——调整力向量法，可较方便地求解复杂的压剪断裂问题；并编制了相应的非线性有限元计算程序。进而对龙滩碾压混凝土重力坝的建基面和碾压层进行了压剪断裂过程分析，得到了裂缝的发展过程及相应的应力、应变场，并对软化模型作了计算比较分析；同时，得到了大坝各高程的材料强度储备系数。最后，得出大坝上游防渗措施和保证水平施工缝具有足够的抗渗要求是保证龙滩大坝稳定安全的关键的结论

Fracture Analysis of the Stability Safety of the Horizontal Construction Joint in Longtan Rollcrete Gravity Dam

A new numerical analysis model of nonlinear fracture mechanics which is suitable for analysising the structure including compression-shear crack compression-shear blunt crack band model is presented.Basing on this model,a new solution method which is named the abjusted force vector method is proposed,and the complicated problem of compression-shear nonlinear finite element method is written.Furthermore,the compression-shear fracture procedures for dam foundation level and roller compacted stratification plane of Longtan rollcrete gravity dam are studied,and corresponding development procedures of crack as well as stress and strain fields are obtained.Besides,softening model is compared with borittle fracture model through computing and analysising.At the same time the reserve factor for material strength of every elevation of the dam are obtined.Finally,the conclusions of that the upstream seepage prevention measure and the impermeable requirement of the horrizontal construction joint for the stability safty of Longtan dam are key points are drown.