沉井结构裂缝宽度限值的选取分析与设计

Design and Analysis of Crack Width Limit Choice about Sinking Well

沉井被用作地下构筑物时,截面配筋往往由裂缝宽度验算确定,按承载力极限状态计算所需配筋小于满足裂缝控制要求所需配筋,特别是刃脚根部以上1.5倍厚度的井壁。对于钢筋混凝土构件的裂缝,有各种不同的裂缝计算理论及包含各种不同变量的、各种不同形式的裂缝计算公式,保护层厚度也有不同的规定。结合具体工程,依据不同的现行规范选取裂缝宽度限值,进行裂缝宽度验算。通过分析表明:根据《混凝土结构耐久性设计规范》进行沉井设计,能在满足耐久性要求条件下减少配筋量多达25%,对类似工程具有借鉴作用。

When the sinking well is used as underground work, reinforcement of structure member is usually controlled by crack analysis. The amount of steel bar calculated by load-bearing capacity less than that controlled by crack width analysis,especially on the wall above cutting curb. There are various theories and formulas about crack analysis of reinforced concrete member,the number of cover to reinforcement is not same o Joining with the actual work ,the paper choose crack width limit and check crack width according to various codes~ By contrast,it is found sinking well design based on 《Code for durability design of concrete structure》 will satisfy durability and reduce the amount of steel bar.