针对软土地区桥侧大面积堆土致使桥梁安全事故频发现状，文中依托某高速公 路匝道桥桥侧大面积堆载后安全性评估工程，利用有限元软件 ABAQUS 建立了桥梁 － 地基土 － 堆载土的计算模型，选取不同桥梁结构形式、堆土维度等变量建立多组研究工 况，模拟分析堆载土挤土效应、地基土层变形、桥梁桩土耦合关系以及桥梁整体结构位 移和内力的变化过程，以评估堆载后桥梁的安全状态; 根据堆载后地基土的变形规律， 探讨了堆土维度差异对桥梁结构的影响; 最后对比分析不同桥梁结构形式非对称堆载下 的安全状态。结果表明: 桥侧大面积堆土后，匝道桥基础弯矩增加 177. 7% ，基础轴力 增加 27. 3% ，主墩及上部结构内力无明显变化，处于安全状态; 桥梁桩基变形、变矩 与侧向位移等特征均与前人研究结论一致; 堆载造成地基土侧向位移主要发生在软弱土 层中，在较大堆载作用下，桥梁基础位移可能超出规范允许值; 降低堆土高度和增大堆 载间距均能有效控制地基土变形，降低桥梁结构的位移大小; 堆土宽度对地基土侧向位 移的影响显著，对沉降的影响较小，清理堆土能有效控制桩基挠曲变形和桥梁水平位 移; 相对墩梁固结形式桥梁，设置伸缩缝和支座后，桥侧大面积堆土容易产生更大的结 构变形，桥梁线形曲率和堆载位置对伸缩缝变形量也有影响。

Aiming at the usually reported accidents induced by soil massively stacked in the bridge side，a numerical simulation for the behavior of pile foundation of a highway ramp bridge subjected to surcharge load was carried out． A computational model of bridge，foundation soil，stacked soil was constructed through the finite element software ABAQUS，and variables such as varied structural forms of bridges and pile dimensions were selected． The effects of soil squeezing，deformation of foundation soil，pile-soil coupling relationship，overall displacement and internal force of the bridge were modeled to assess the safety status of the bridge． The influence of dimensions of the pile on the stability of bridge structure was discussed according to the deformation law of the foundation soil，and the safety status of different bridge structures under asymmetric loading were comparatively analyzed． The results show: when mass earth is heaped laterally on the bridge，the bending moment and axial force of the bridge increase by 177. 7% and 27. 3% ，respectively; the internal forces of the main pier and upper structure has no obvious change，indicating that the ramp bridge is safe; the deformation，moment change and the lateral displacement of the bridge pile foundation are consistent with the existing conclusions; the lateral displacement mainly occurs in the layer of soft soil，which may exceed the allowable value under large loading; decreasing the height of the stacked soil and increasing the space between soil piles can prevent the deformation of the foundation soil and reduce the displacements of the bridge structure; the width of the stacked soil has significant influence on the lateral displacements of the foundation soil and little influence on the sink of the foundation soil; clearing the soil near the bridge can effectively control pile foundation deformation and horizontal displacement; the bridge is prone to greater structural deformation under the influence of massively stacked soil after setting expansion joints and supports; linear curvature and load position also have an effect on expansion joint of bridge deformation．