碾压与常态混凝土组合的某升船机上闸首结构配筋方案

Determination of structural reinforcement schemes for upper lock head of a ship lift made of RCC and normal concrete

针对既要控制裂缝宽度又要控制裂缝长度的碾压与常态混凝土组成的某升船机上闸首整体坞式结构,通过对比不同配筋方案的钢筋混凝土非线性有限元计算结果,提出以材料强度标准值所得裂缝长度和宽度进行底板裂缝控制从而确定底板常态混凝土最小厚度,以材料强度平均值所得裂缝长度确定钢筋布置范围的计算原则;同时给出了符合限裂设计要求的底板常态混凝土最小厚度和配筋方案,并探讨了缝面水压的不同施加方式对裂缝的影响。计算结果表明,当缝面水压按全水头分布施加时,若裂缝长度超过钢筋布置范围,则裂缝会不断扩展,引起结构失效;缝面水压按渗透压力分布和三角形分布施加时,裂缝扩展能够收敛,且前者所得的裂缝宽度和长度均大于后者。

It is necessary to control crack width and crack length for the upper lock head of a ship lift, which is generally a dock-type structure made of roller compacted concrete （ RCC） and normal concrete. Based on the comparison of the nonlinear finite element calculation results of reinforced concrete with different structural reinforcement schemes, a calculation principle was proposed. According to this principle, concrete standard strength is used to control crack width and crack length in the bottom slab and to determine the minimum thickness of normal concrete of the bottom slab. The crack length, determined by average strength of concrete, is used to determine the scope of reinforcement. The minimum thickness and the structural reinforcement scheme of normal concrete bottom slab were suggested. The influence of applying ways of water pressure on the crack surface on cracks was analyzed. The results showed that when the water pressure on the crack surface was full water head, the cracks expanded until it exceeded the reinforcement scope, which caused structural failure. When the water pressure was seepage pressure and it was applied in a triangular distribution, the cracks was steady;both crack width and crack length obtained in the scenario with full water head are larger than that in the scenario with seepage pressure.