碾压混凝土断裂特性与诱导缝开裂条件研究  

Study on Fracture Property of RCC and Cracking Condition of Induced Joint

作　　者：陈媛[1] 张林[1] 何江达[1] 王东[1] 

机构地区：[1]四川大学水电学院,四川成都610065

出　　处：《四川大学学报（工程科学版）》2005年第3期15-19,共5页Journal of Sichuan University (Engineering Science Edition)

基　　金："九五"国家科技攻关资助项目(96-220-02-01-03)

摘　　要：为了研究碾压混凝土的断裂特性和诱导缝的开裂条件,对多组碾压混凝土试件进行3点弯曲梁断裂试验,获得了碾压混凝土的抗拉、抗压强度,断裂韧度和断裂能,以及荷载-加载点挠度曲线、荷载-缝端开度曲线。根据断裂韧度和应力强度因子的关系,建立了结构模型中诱导缝的开裂相似条件。通过3点弯曲梁的非线性开裂计算,由试验测得的荷载-挠度曲线推求出材料的拉应变软化曲线,并将材料的单轴抗拉强度修正为三维状态下的抗拉强度,最终建立了基于虚拟裂缝模型的诱导缝开裂计算条件。试验研究和计算分析所获得的碾压混凝土的开裂特性和开裂条件应用于沙牌碾压混凝土高拱坝的结构模型试验和数值计算中,为研究混凝土高拱坝的开裂和破坏机理提供基本依据。In order to study fracture property of RCC and cracking condition of induced joint, three point banding beam fracture tests of RCC have been carried out in this paper. Some parameters and typical curves of fracture property are obtained, such as tensile strength, compressive strength, fracture toughness, fracture energy, curve of load vs. load point deflection, and curve of load vs. crack jaw opening. According to the relation of fracture toughness and stress intensity factor, the cracking similarity condition of induced joint in structural model is established. Through nonlinear cracking calculation of three point bending beam, the curve of load vs. load point deflection is used to deduce the tensile strain softening curve. Furthermore, the tensile strength of material is modified on 3-D condition. Finally, the cracking calculating condition in numerical calculation of induced joint is established, which is based on the fictitious crack model. These fracture property parameters and cracking conditions are adopted in the structural model test and the numerical calculation of the Sichuan Shapai RCC arch dam, the highest one in the world at present. These results are the base references for researching cracking and destructive mechanism of the high RCC arch dam.

关 键 词：碾压混凝土 诱导缝 断裂韧度 断裂能 开裂条件 

分 类 号：TV32[水利工程—水工结构工程] TV313