中文摘要：

对长江三峡工程泄洪坝段原材料制成的大坝混凝土及其湿筛混凝土试件做直接拉伸试验,得到大坝混凝土及其湿筛混凝土断裂过程区的本构关系.结合标准三点弯曲切口梁试验,运用双K断裂模型,得到大坝混凝土和湿筛混凝土的双K断裂参数.试验结果表明,三峡大坝混凝土的起裂和失稳韧度均大于其湿筛混凝土,前者分别为后者的1.14和1.19倍.

英文摘要：

Using dam and wet-screening concrete specimens made of raw componential materials, as used in the discharge segment of the Three Gorges Dam, uniaxial tension tests were conducted to achieve the softening constitutive relations of fracture process zone of the dam and wet-screening concrete. Combining with three-point bending notched beam tests, adopting double-K fracture model, the double-K fracture parameters of the dam and wet-screening concrete were obtained. The results show that initial fracture toughness and unstable fracture toughness of the dam concrete are 1. 14 times and 1. 19 times those of the wet-screening concrete respectively.