箱涵顶进施工中沉降监测及有限元分析OA

To reveal the settlement variation patterns of the overburden layer subsidence during the box culvert jacking influenced by overburden layer thickness,grouting reinforcement,and friction-reduction treatment,and to improve the construction control technology for the box culvert jacking,settlement monitoring and displacement analysis were performed based on an actual bridge and culvert engineering project.The finite element software ABAQUS was used to compare the construction settlement monitoring and verify the accuracy of the model.By establishing three-dimensional solid finite element models of the soil and box culvert with different overburden layer thicknesses(2 m,3 m,and 5 m),the relationsip between jacking displacement and overburden layer settlement during the box culverts jacking process was analyzed.The results show that overburden layer thickness has a significant influence on surface settlement.Compared with the 2 m case,settlements amounts of 3 m and 5 m thicknesses were reduced by 21.3%and 32.7%,respectively.Thicker overburden layers help distribute jacking pressure more evenly,reduce soil deformation,and effectively decrease settlement.In the 5 m overburden condition,additional measures such as grouting reinforcement of the upper soil and friction-reduction treatment at the base further decrease settlement by 7.0 mm and 3.7 mm,respectively.Settlement is mainly concentrated within 30 m of the culvert centerline,and the influence rapidly decreases beyond this range.The study can help explore the factors influencing the overburden layer settlement during the the box culvert jacking and offer theoretical support for the optimal design of box culvert construction under silty clay conditions.