城市软土复合地基施工钢波纹管拱涵的力学特性研究

Research on Mechanical Characteristics of Steel Corrugated Pipe Arch Culvert Constructed on Urban Soft Soil Composite Foundation

软土地区进行工程建设,控制施工的沉降变形是工程面临的重要问题。以城市路桥和地铁建设为背景,研究了建立在加固后复合地基上的超大跨度连拱钢波纹管桥的力学稳定性。根据室内试验结果,采用有限差分法进行数值分析,钢波纹管一次性安装完成,管周回填土分2次回填。结果表明,软土地基中使用三轴搅拌桩加固效果良好;大跨度钢波纹管受力后容易产生较大竖向变形,因此在回填管周土时,需要对钢波纹管进行临时稳定性支撑;由于地层的不均匀性,钢波纹管拱涵局部位置出现较大的沉降,钢波纹管截面受力主要集中在管顶及周围、管腰拐点、管底及其周围,施工期应给予重视。

For engineering construction in soft soil areas,how to improve the bearing capacity of the foundation and control the settle‐ment is the most important problem faced by the construction.Based on the city construction of road bridge and tunnel,the mechanical sta‐bility of the super-long-span multiple arch steel corrugated pipe bridge on the reinforced composite foundation is investigated using finite dif‐ference method.Numerical analysis using finite difference method based on the laboratory tests results is carried out.The steel corrugated pipe culvert structure is installed by one-step,the surrounding backfill is divided into two times.The results show that the use of triaxial mixing piles in soft soil foundations has a good reinforcement effect.On the whole,there is large vertical deformation for the large-span steel corrugated pipe after subjected to the force action.Therefore,the steel corrugated pipe needs temporary stability support when backfill‐ing the soil around the pipe.Moreover,the steel corrugated pipe culvert has a large settlement in the local position due to the inhomogene‐ity of the stratum.The cross-sectional force of the steel corrugated pipe is mainly concentrated on the top,inflection point of pipe waist,around the bottom of pipe.Attentions should be paid during the construction.