高铁桥梁补桩后桩基沉降数值模拟

Numerical Analysis of Settlement after Pile Foundation Patching of Bridges on High-Speed Railway Lines

以某既有线铁路桥梁桩基补桩工程为研究对象,介绍了地基的地层情况,采用有限元软件分析了帮宽补桩自重工况和活载工况下桩基及承台的沉降。结果表明:①在帮宽补桩自重工况下老桩最大沉降为1.4 mm,新桩沉降分别为1.8 mm和1.9 mm,相邻的新老桩基最大沉降差0.5 mm,满足规范限值要求;旧承台边缘位置沉降0.15 mm,帮宽承台边缘沉降2 mm,桥墩所在位置沉降1.35 mm;新老承台接缝面最大主拉应力为0.334 MPa,满足规范中混凝土抗拉限值要求。②在列车活载作用下:在荷载达到8000 kN时,桩基沉降最大值为3.07 mm,最小值2.77 mm,在桩基沉降最大值达到2 mm时,荷载为6405 kN。

Taking an existing railroad bridge pile foundation patching project as the research object,the ground conditions of the foundation are introduced,and the settlement of the pile foundation and bearing platform under the self-weight condition and live load condition of the gang-width patching pile is analyzed using finite element software.The results show that:①the maximum settlement of the old pile is 1.4mm,the settlement of the new pile is 1.8mm and 1.9mm respectively,and the maximum settlement difference of the adjacent old and new pile foundation is 0.5mm,which meets the specification limit;the settlement of the edge of the old bearing platform is 0.15mm,the settlement of the edge of the wide bearing platform is 2mm,and the settlement of the location of the bridge pier is 1.35mm;the joint surface of the old and new bearing platform The maximum main tensile stress is 0.334MPa,which meets the requirements of concrete tensile limit in the specification.②Under the action of graded load:the maximum value of pile settlement is 3.07mm and the minimum value is 2.77mm when the load reaches 8000kN,and the load is 6405kN when the maximum value of pile settlement reaches 2mm.