不同土层参数对砖石排水拱涵受力影响

The influence of different soil parameters on the force of masonry drainage arch culvert

为研究不同土层参数对城镇砖石排水拱涵受力特性的影响,依托红旗渠项目试验段建立有限元模型,分析了地基土层的承载力和泊松比、结构外侧土层的含水量和泊松比及覆土层厚度对砖石拱涵结构受力的影响。研究结果表明:随着地基土层承载力的增大,拱趾内侧压应力增大,拱顶内侧拉应力、拱圈变形及拱圈受拉区域均减小。随着结构外侧土层含水量的增大,拱顶内侧拉应力、拱趾内侧压应力、侧墙底部内侧压应力、拱顶竖向变形及拱圈受拉区域均增大,且结构外侧土层含水量为10%-20%时,含水量变化对拱涵受力及拱圈变形影响较大。随着地基土层或结构外侧土层泊松比增大,拱顶内侧拉应力、拱趾内侧压应力、侧墙底部内侧压应力及拱圈变形均减小。随着覆土层厚度增加,拱顶内侧拉应力、拱趾内侧压应力、侧墙底部内侧压应力及拱顶竖向变形均呈线性递增趋势,且拱圈受拉区域增大。且结论均与红旗渠试验段现场检测结果较吻合,该研究成果可为地下拱涵结构检测鉴定提供参考。

In order to study the influence of different soil parameters on the mechanical characteristic of urban masonry drainage arch culvert,the finite element simulation model was built based on the test section of the Hongqi Canal project. The impact of the bearing capacity and the Poisson’s ratio of foundation soil,the water content andthe Poisson’s ratio of the soil layer outside the structure and the overburden soil thickness on the mechanical characteristic of masonry drainage arch culver were analyzed. The results show that,with the increase of bearing capacity of foundation soil,the compressive stress inside the arch toe increases,the tensile stress inside the vault,the deformation of arch ring and the tension area of arch ring decrease.With the increase of the water content of the outer soil layer of the structure,the tensile stress inside the vault,the compressive stress inside the arch toe,the compressive stress inside the bottom of the side wall,the vertical deformation of the vault and the tensile area of the arch ring increase.When the water content of the outer soil layer of the structure is10 %-20 %,the change of water content has a great influence on the stress of arch culvert and the deformation of arch ring. With the increase of the Poisson’s ratio of the soil layer of the foundation or the soil layer outside the structure,the tensile stress inside the vault,the compressive stress inside the arch toe,the compressive stress inside the bottom of the side wall and the deformation of the arch ring decrease.With the increase of the thickness of the overburden layer,the tensile stress inside the vault,the compressive stress inside the arch toe,the compressive stress inside the bottom of the side wall and the vertical deformation of the vault increase linearly,and the tensile area of the arch ring increases.The analysis conclusions are in good agreement with the field test results of the Hongqi Canal test section,which can provide reference for the detection and identification of underground arch culvert structure.