地面堆卸载作用对铁路桥墩沉降的影响分析

邻近堆卸载会对桥梁桩基造成不利影响,严重时将影响铁路的运行质量和安全,本文以一受邻近煤矿开采影响产生偏移的大桥为例予以分析。实测桥梁周边山体卸载引起的地基推移和桥梁桩基的变形,以此为基础建立有限元模型进行多角度数值分析,得出地基推移、对称堆载、不对称堆载及不同堆载高度对桩基沉降、变形和最大主应力的影响。计算结果表明,以混凝土允许主拉应力为控制指标,该桥梁桩基均匀堆载高度最大不能超过13 m,不对称堆载高度最大不能超过7 m。研究结果为维护整治提供了技术支持。

Influence of Ground Surcharge and Unloading on Settlement of Railway Bridge Pier

Surcharge and unloading adversely affect bridge pile foundation,even threatening the quality and safety of railway operation.In this paper,the engineering background is a bridge being subjected to displacement due to coal mining.The foundation displacement and the bridge pile deformation induced by the unloading of adjacent mountain are measured.A f inite element model is built for multiple numerical analysis.The inf luences of foundation displacement,symmetric/asymmetric surcharge and surcharge height on pile settlement,deformation and maximum principle stress are analyzed.The results show that the uniform surcharge height should be not greater than 13 m and the asymmetric surcharge height should be not greater than 7 m based on the concrete allowable principle tensile stress.It provides technical support for maintenance.