大面积单侧堆载对高速铁路桥梁墩台影响的数值分析

Numerical analysis on inf luence of large-area one-side surcharge load on abutments and piers of high speed railway bridges

基于某高速铁路桥梁实际地质条件和现场堆载情况,运用ABAQUS有限元软件建立高速铁路桥梁墩台、基础及地基土相互作用有限元模型,分别假设地基土为弹性(大变形)和理想弹塑性,分析了桥梁墩台在大面积单侧堆载作用下的受力变形特性,包括墩顶中心变形、地基与桩基侧向变形沿深度变化、地基与桩基侧向应力沿深度变化等。研究结果表明:单侧大面积堆载是桥梁桩基产生水平位移的主要原因;地基黏土层取为理想弹塑性时计算的墩顶变形与地基土侧向应力明显大于取为弹性时计算值,且与现场实测值较为接近,说明地基土体发生了一定的塑性变形造成了桩基倾斜。计算结果为桥梁墩台倾斜的成因及处置措施提供了理论依据。

Based on the actual geological conditions and the case of a high adjacent surcharge loads,a threedimensional high speed railway bridge pier-foundation-soil interaction f inite element model was established with ABAQU S.Soils were assumed elastic（large deformation） and simulated with a ideal elastic-plastic model.The deformation and stress characteristics of bridge pier subjected to adjacent surcharge loads were analyzed respectively,including the deformation of pier top,the variations of the lateral deformation and the lateral stress along the depth of pile foundation and soils,etc.Results indicated that the single adjacent surcharge loads was the main factor to cause lateral deformation of bridge pile foundation.Two cases were studied：the clay layer of soil foundation was assumed ideal elastic-plastic or elastic.The lateral stress at bridge pier top was signif icantly greater in the former case than that in the latter,and it was closer to the measured results.This suggested that plastic deformation occurred in the soil and the pile foundation became declining.Finally,the numerical results were provided to propose the theoretical basis for the behavior and treatment measures.