U型桥台常见病害机理与加固技术研究

Study on Typical Disease Mechanism and Reinforcement Technology for U-Shaped Abutment

U型桥台作为经典的桥台结构形式,在桥梁设计中运用十分广泛。在桥梁运营过程中,U型桥台由于受力形式复杂,容易出现各种病害。根据大量的现场调查,U型桥台的常见病害具有共性。本文在归纳U型桥台主要病害类型的基础上,深入分析U型桥台病害机理,提出U型桥台加固方法。运用ANSYS有限元软件的非线性分析功能,建立加固前后桥台的三维空间实体模型,通过不同高度和宽度的桥台受力分析,对比研究加固前后U型桥台的应力和位移情况,从而对各种加固方法的加固效应加以评估。研究表明:土压力等荷载作用下导致的台身主拉应力偏大,尤其是前墙与侧墙交汇处,是桥台台身开裂的主要内因,因地制宜采用合适的加固方式可有效防止桥台开裂。

As a classic structural form, U-shaped abutment is widely used in bridge design. In the process of bridge operation, U-shaped abutment is prone to various diseases due to the complex stress. According to a great deal of field surveies, the typical diseases of U-shaped abutment have common character. Based on major disease types,this paper further analyzed disease mechanism and proposed reinforcement methods on U-shaped bridge abutment. By applying nonlinear analysis function of ANSYS finite element software and establishing three-dimensional solid model for abutment before and after reinforcement, with the mechanical analysis under different height and width of abutment, this paper is intended to assess reinforcement effect of various methods via relative analysis on stress and displacement before and after reinforcement. Investigation shows that the larger principal tensile stresses under multiple loads such as earth pressure are the main cause of cracking of abutment, especially at junction of front wall and side wall. On the basic of actual situations, the suitable reinforcement methods can keep U-shaped abutment from cracking.