新型高填方桥台设计研究

Design and Research of New High-fill Abutment

摘要:

在台后填方高度超过10 m且台前无法放坡的高填方地形路段，桥台需要能抵抗台后较大的土压力，具有较大的竖向承载力和水平承载力且能克服台后填土较大的不均匀沉降，而传统桥台类型难以满足上述需求。为此，以某台后填方为10.6 m的跨站前广场桥为例，提出在台身后设置箱室，并在纵桥向采用3排桩基的箱型桥台方案；同时根据桥梁总体布置，对该新型高填方桥台进行了构造设计并采用有限元软件计算验证该桥台结构的可行性。结果表明：新型高填方桥台各力学性能指标均满足规范要求，能够适用于台后高填方的地形，台前无需放坡即可保证桥下站前广场的通行空间。

Abstract:

In the high-fill terrain section where the fill height behind the abutment is more than 10 m and the slope cannot be placed in front of the abutment, the abutment must be able to resist the large earth pressure behind the abutment and have the large vertical and horizontal bearing capacities to overcome the large uneven settlement of the fill behind the abutment. But the type of traditional abutment is hard to meet the above demands. Taking a cross-station square bridge with 10.6 m fill behind the abutment as an example, a box chamber is proposed to set behind the abutment body, and the box abutment scheme with three rows of pile foundations in the longitudinal direction is adopted. According to the general layout of the bridge, the structural design of the new high-fill abutment is carried out and the finite element software is used to calculate and verify the feasibility of the abutment structure. The results show that each mechanical performance index of the abutment meets the specification requirements and it can be applied to the terrain with high fill behind the abutment. There is no need to slope in front of the abutment to ensure the passage space of the station square under the bridge.