某工程混凝土溢洪道浇筑块开裂分析与结构安全性评价

Cracking Analysis and Reliability Assessment for Concrete spillway

某工程混凝土溢洪道浇筑过程中,在2#坝段第三层混凝土浇筑层出现平行于坝轴线方向的混凝土开裂,作者以温度徐变应力场仿真分析为手段,分析混凝土开裂成因,结果表明开裂是由于混凝土内部温升和外部约束共同作用结果,在昼夜温差大的情况下,浇筑后大体积混凝土表面未进行有效保温措施是造成混凝土开裂的主要原因;基于施工过程仿真的分析方法,分析开裂和修补加固后溢洪道的应力分布,开展溢洪道结构整体安全性的评估,结果表明裂缝对结构局部受力有影响,结构整体受力不受影响。建议对所有开裂部位进行灌浆处理,继续开展水工结构的温度观测,开展温度控制的理论分析。

The cracking of spillway under construction is a usual phenomenon.The temperature creep stress analysis was developed to simulate the properties of concrete,the construction process,and the variation of environmental effect,so as to quantitatively reveal the mechanism of cracking.It indicates that the crack is result from the combined action with external restraint and internal temperature rising,non-effective insulating method with large range variations of surrounding temperature.To obtain spillway reliability,based on construction simulation,the stress distribution with cracking was carried out;It shows that the local stress distribution is changed,while the integer stress distribution is unchanged,and it is suggested that grouting cement for concrete cracking and temperature monitoring for big size concrete construction.