基于湿度-结构耦合作用的船闸闸墙干缩开裂研究

Research on drying shrinkage cracking of lock chamber wall based on wet-structure coupling theory

根据船闸闸墙在施工期极易产生多种非荷载裂缝这一现象。以京杭运河某船闸实际资料为基础,采用类比温度场的数值模拟的方法求解湿度场,进一步进行湿-结构耦合分析,通过研究干燥收缩拉应力的变化过程以探讨控制干燥收缩裂缝发展的方法。数值模拟结果表明:(1)闸墙拆模后前10 d的干燥收缩拉应力发展迅速,50 d左右后干燥收缩拉应力的极值已趋于稳定;(2)闸墙底部和2/3高度处属于"应力危险区",易产生干缩裂缝;(3)通过控制结构尺寸的变化,发现减小闸室底板厚度和结构段长度可减小干缩拉应力的极值,且后者效果更显著。

Based on the measured data of a ship lock along the Beijing-Hangzhou canal, the characteristics of different non-loaded cracks which occur during the construction of the lock chamber wall were analyzed. Numerical modeling method applied in temperature field was used to analyze humidity field. The wet-structure coupling meth- od was carried out to research the variation trend of drying shrinkage pulling stress. The results show that ： （ 1 ） The maximum value of drying shrinkage pulling stress grows rapidly during the first 10 days after removing the form moulds. After removing the moulds for 50 days, the value is stable. （2）Drying shrinkage cracks are likely to occur at the bottom part and 2/3 height of the lock chamber wall.（3）The maximum value of drying shrinkage cracks can be lowered by decreasing the thickness of lock chamber floor and the structure length. The later method works more el- fectively.