摘要
通过多组不同削弱度的深埋椭圆裂缝、深埋矩形裂缝、穿透裂缝三种形式的碾压混凝土试件单轴拉伸试验结果,建立深埋矩形裂缝碾压混凝土试件的应力强度因子的近似解析表达式,考虑尺寸效应得到碾压混凝土材料的断裂韧度。根据碾压混凝土拱坝诱导缝构造特点,分别将矩形诱导缝简化为修正穿透裂缝模型和修正深埋椭圆裂缝模型,假定为I型开裂,考虑相邻裂缝的影响,采用虚拟裂缝模型和线弹性断裂力学相结合的方法建立裂缝失稳扩展时的亚临界扩展量和等效断裂韧度的解析表达式,应用双K断裂准则,建立碾压混凝土拱坝诱导缝开裂的等效应力准则。并将此结果应用到三维非线性应力场仿真计算中,对沙牌碾压混凝土拱坝进行非线性开裂计算分析。
An approximate formula of stress intensity factor for roller compacted concrete （RCC） specimens with immerged rectangle cracks is determined by means of a uniaxial tension test, in which different types of preformed crack specimens （i. e. immerged elliptical crack, immerged rectangular crack and penetrable crack, respectively） with different weakened ratios are tested. Considering the size effect, the fracture toughness is proposed, which can be employed to analyze the cracking of RCC arch dam. According to its characteristics, the rectangular induction joints are simplified into modified penetrable cracks and immerged elliptical cracks respectively. Based on the assumption of model I fracture, with the influence of adjacent cracks, another analytical formula is constructed to study the sub - critical extension and the equivalent fracture toughness during the unstable propagation of cracks, by coupling linear elastic fracture mechanics （LEFM） and fictitious crack model （FCM）. Based on the ＇ Double K Fracture Criterion＇, an equivalent stress cracking criterion for RCC induction joints is established and applied to 3 - D nonlinear stress simulation analysis. Using this theory, nonlinear cracking analysis of the ShaPai RCC arc dam is performed.
出处
《土木工程学报》
EI
CSCD
北大核心
2005年第12期24-31,共8页
China Civil Engineering Journal
基金
国家自然科学基金资助项目(50179002)
中国博士后基金资助项目(2005037149)
关键词
碾压混凝土拱坝
诱导缝
应力强度因子
断裂韧度
等效应力准则
RCC arch dam
induced joints
stress intensity factor
fracture toughness
equivalent stress cracking criterion
