船闸等薄壁结构长间歇后温控防裂措施研究

Study on Temperature Control and Crack Prevention Measures for Thin-Walled Structures Such as Ship Lock after Long Intervals

船闸闸墙浇筑与底板之间必然存在长间歇期。对于大体积混凝土而言,长间歇是导致新浇混凝土开裂的主要内因之一。基于上述问题,结合船闸长间歇浇筑特征及结构特征,仿真分析探索了导致闸墙新浇混凝土裂缝产生的主要原因。混凝土浇筑的长间歇期会增大约束力,产生新老混凝土温差,从而导致温度应力超标诱发竖向裂缝。在上述分析结果的基础上,进一步分析降低新浇混凝土温度应力的关键措施,提出分层分块浇筑的建议。

There must be a long interval between the pouring of gate wall and bottom plate of ship lock.For mass concrete,long interval is one of the main internal causes of fresh concrete cracking.In view to above problem,combined with the characteristics of long interval pouring and the structural characteristics of ship lock,the simulation is carried out to explore the main causes of cracking in newly poured concrete.The long interval period of concrete pouring will increase the restraint force and cause the temperature difference between new and old concrete,which will result to excessive temperature stress and vertical cracks.At the same time,based on above analysis results,a key measure to reduce the temperature stress of fresh concrete is explored,and the suggestion of layered and block concrete pouring is put forward.