坞式闸室混凝土裂缝控制措施

Control measures of concrete cracks in dock-type lock chamber

坞式闸室在以往的工程中经常会在闸室底板和倒角产生混凝土裂缝,底板裂缝通过后浇带设计加以解决,后浇带处理不当会产生人为裂缝、同时也会带来施工不便。探讨坞式闸室底板整体浇筑的可行性,研究采用三维有限单元法模拟船闸坞式闸室的施工过程,分析指出闸室底板和倒角可能产生裂缝的成因,提出应用预应力加固技术防治混凝土裂缝,同时提出了预应力布置参数。计算结果表明,施加预应力后可有效降低底板和倒角处的拉应力,使其低于混凝土应力控制标准,达到了防治裂缝的目的。

In the past projects,concrete cracks often occur in the bottom and chamfer of the dock-type lock chamber.The cracks in the bottom are solved by the design of post-pouring strip.The improper treatment of the post-pouring strip will result in artificial cracks and inconvenience in construction.In this paper,the feasibility of integral pouring of the bottom slab of dock-type lock chamber is discussed.The construction process of dock-type lock chamber is simulated by three-dimensional finite element method,and the causes of cracks in the bottom slab and chamfer of lock chamber are analyzed and pointed out.The application of prestressing reinforcement technology to prevent concrete cracks is put forward,at the same time,the prestressing layout parameters are put forward.The calculation results show that the tension stress at the bottom and chamfer can be effectively reduced by applying prestressing force,which is lower than the concrete stress control standard and achieves the purpose of crack prevention.