超深检查井的空间受力分析和UHPC应用探讨

Analysis on Spatial Stress of Ultra-deep Manhole and Discussion on Application of UHPC

摘要:

为提高城市检查井结构的使用性能，结合矩形混凝土跌水井对非标准检查井井壁结构的受力特点进行分析，并对基于UHPC的井壁优化设计进行研究。首先，利用三维板壳有限元模型对非标准检查井沿高度、宽度方向的弯矩和面外位移进行了详细分析；再基于空间分析结果和预定设计目标，对采用不同材料及钢筋布置的井壁结构设计优化进行了对比分析。结果表明：各侧壁板在两个方向的弯矩均不可忽略，且面外变形具有双向板的特点，建议当井室高度和宽度比小于5时，采用三维空间模型进行分析；考虑空间受力特点，采用普通混凝土的井壁厚度可减小20%，采用UHPC的井壁厚度可减小40%，同时钢筋用量减少约17%，可为非标准检查井的结构计算和设计提供理论依据，为UHPC在检查井井壁结构中的实际工程应用提供参考。

Abstract:

In order to improve the using performance of the urban manhole structure, the stress features of wall structure of the non-standard manhole are analyzed in combination with the rectangular concrete water drop well, and the optimal design of the manhole wall based on UHPC is studied. Firstly, the three-dimensional plate-shell finite element model is used to analyze the bending moment and out-of-plane displacement of the non-standard manhole along the height and width directions in detail. Based on the spatial analysis results and the predetermined design objectives, the design optimization of the manhole wall structure with different materials and reinforcement arrangements is compared and analyzed. The results show that the bending moments of each sidewall plate in both directions are not negligible, and the out-of-plane deformation has the characteristics of two-way plates. It is recommended to use the three-dimensional spatial model for analysis when the ratio of height to width of the manhole chamber is less than 5. Considering the characteristics of spatial stress, the thickness of the manhole wall can be reduced by 20% for ordinary concrete and 40% for UHPC, and the amount of reinforcement can be reduced by about 17%, which can provide a theoretical basis for the structural calculation and design of non-standard manhole, and provide a reference for the practical engineering application of UHPC in the wall structure of manhole.