现场浇筑大坝混凝土起裂断裂韧度研究  

Initial fracture toughness of site-casting dam concrete

作　　者：管俊峰[1,2,3] 李庆斌[2] 吴智敏[3] 周绍武[4] 

机构地区：[1]华北水利水电大学土木与交通学院,河南郑州450011 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [3]大连理工大学海岸与近海工程国家重点实验室,辽宁大连116024 [4]中国长江三峡集团公司,北京100038

出　　处：《水利学报》2014年第12期1487-1492,共6页Journal of Hydraulic Engineering

基　　金：国家自然科学基金重点资助项目(51339003);国家自然科学基金资助项目(51209094);海岸和近海工程国家重点实验室基金项目(LP1211)

摘　　要：利用我国西南部某特高拱坝施工现场的拌合楼,浇筑成型骨料最大粒径150 mm的大坝混凝土楔入劈拉试件,试件尺寸分别为800 mm×800 mm×450 mm、1 000 mm×1000 mm×450 mm和1 200 mm×1 200 mm×450mm。通过试验获得现场浇筑大坝混凝土试件的起裂荷载,进而由有限元计算得到其起裂断裂韧度值,分析了龄期变化对起裂断裂韧度的影响规律,给出了起裂断裂韧度随试件尺寸的变化规律。结果表明,通过现场浇筑试件,得到大坝混凝土的起裂断裂韧度,能够真实反映大坝的实际断裂性能。现场浇筑大坝混凝土的起裂断裂韧度随着龄期增加而增加,180 d龄期的现场浇筑大坝混凝土的起裂断裂韧度在试件有效高度800~1 200 mm范围内不存在明显的尺寸效应。In this paper,the study aims to examine the initial fracture toughness KIinic of dam concrete obtained directly from a construction site. All test specimens with a maximum aggregate size of dmax = 150 mm were cast on site of an actual super-high arch dam in southwest China, and the dimensions of the wedge-splitting specimen were 800 mm×800 mm×450 mm,1000 mm×1000 mm×450 mm,1200 mm×1200 mm×450 mm, respectively. Based on the experimentally acquired initial cracking loads, the initial fracture toughness KI^inic of the site-casting specimens was numerically obtained using the finite element method. Furthermore,the effect of specimen age and size on initial fracture toughness was analyzed and discussed. The results show that real fracture parameter KI^inic of a super-high arch dam could be obtained by casting the test specimens at the construction site. The initial fracture toughness KI^inic of the site-casting specimens increases with specimen age. The KI^inic of the site-casting specimens at the age of 180 days is independent of specimen size at depths of 800 mm to 1200 mm.

关 键 词：现场浇筑 大坝混凝土 真实断裂参数 起裂断裂韧度 试件龄期 试件尺寸 

分 类 号：TV313[水利工程—水工结构工程] TV41