龙滩碾压混凝土重力坝坝体稳定性研究

Study of the Stability Safety of Longtan Rollcrete Gravity Dam

本文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──压剪钝裂纹带模型，并提出其求解方法──调整力向量法；编程分析了龙滩碾压混凝土重力坝的建基面和碾压层面的压剪断裂过程，得到了裂纹的发展过程、相应的应力、应变场及大坝各高程的材料强度储备系数，并比较分析了软化模型和脆断模型；崐最后，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。

ln this paper , 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 , and a new solution method which is named the adjusted force vector method is proposed. The compression - shear fracture procedures for dam foundation level and roller compacted stratification plane of Longtan rollcrete gravity dam are studied through writting programe , and the corresponding development procedures of crack , the stress and strain fields as well as the reserve factor for material strength of every elevation of the dam are obtained. Besides , softening model is compared with brittle fracture model through computing and analysising. Finally , the conclusions that the upstream seepage prevention measure and the impermeable requirement of the horizontal construction joint for the stability safety of Longtan dam are key points are drown.