中文摘要：

针对水闸混凝土在施工期易开裂这一问题，介绍了混凝土结构的裂缝机理，认为结构的温差和约束是裂缝产生的主要原因，而裂缝的防止可以从优化混凝土配合比、改进施工技术等方面入手。采用三维有限单元法对某大型水闸混凝土进行了仿真计算，分析了其裂缝成因，并提出了相应的温控防裂措施。较大的温降收缩和底板的强约束是造成其裂缝形成的直接原因，而门槽处混凝土结构断面尺寸的突然减半又使得门槽处应力陡然倍增，超过混凝土的即时抗拉强度，产生裂缝。降低混凝土的最高温度和温度变形是防止后期裂缝的关键。过度保温对早期减小温差和防裂有利，但是会增大最高温度，进而增大后期温降幅度和基础温差，对防裂不利。

英文摘要：

Abstract： The sluice concrete during construction period is easy to crack. To this problem, this paper introduced the crack mechanism of concrete structure, considered the structure＇ s temperature difference and restraint were the main cause of cracks. The prevent method of cracks included the optimization of concrete mixture ratio, construction technology improvement and so on. This paper used three-dimensional finite element method to analyze the cause of crack and put forward the measures of temperature control and crack prevention. Strong constraint coming from the floor and larger temperature shrinkage was the direct reason to cause the cracks, while the concrete gate groove structure section size was half of the gate slot and stress doubled, exceeding the tensile strength of concrete. This paper considered that reducing the maximum temperature and temperature de- formation of concrete is the key to prevent late cracks. Excessive heat preservation is beneficial to reduce the temperature difference and the early crack, but will increase the maximum temperature increase, later temperature drop and foundation temneralure difference.