北京地铁周边构筑物振动强度预测模型修正研究

Correction of vibration intensity prediction model for surrounding structures of Beijing Subway and study on structural safety status

在城市轨道交通发展大背景下,地铁运行引发的结构和环境振动问题亟待解决。文中详细分析了考虑场地条件的结构物振动强度的影响因素,结合结构物振动响应数值模拟结果,通过距离修正和建筑物高度修正,消除了建筑物高度、室内外等因素的限制,建立了更加准确的振动预测模型。以北京市丰台区地铁四号线公益西桥站作为试验场地,采用自主研发的ADVM阵列式位移-振动进行现场实测,通过建立结构体动态应力计算公式,对典型地铁结构的动力响应和安全状态进行了分析。研究结果表明,结构所受动态应力与结构质点振动速度成正比、与结构质点振动频率成反比。动态应力与结构本身的抗拉强度的比值可作为结构振动安全的衡量标准。从检测获得的数据分析结果可知,结构体动态应力值小于结构自身的抗拉强度,对结构稳定性产生影响,但随着地铁运营年限的增加,轨道磨损加重,引发的振动变大。

In the context of the development of urban rail transit,the structural and environmental vibration problems caused by subway operation urgently need to be solved.This article provides a detailed analysis of the factors affecting the vibration intensity of structures considering site conditions.Based on the numerical simulation results of structural vibration response,the limitations of building height,indoor and outdoor factors are eliminated through distance correction and building height correction,and a more accurate vibration prediction model is established.Using the Gongyi Xiqiao Station on Line 4 of the Fengtai District Subway in Beijing as the test site,the independently developed ADVM array displacement vibration method was used for on-site measurement.By establishing a dynamic stress calculation formula for the structural body,the dynamic response and safety status of typical subway structures were analyzed.The research results indicate that the dynamic stress on the structure is directly proportional to the vibration velocity of the structural particle and inversely proportional to the vibration frequency of the structural particle.The ratio of dynamic stress to the tensile strength of the structure itself can be used as a measure of structural vibration safety.According to the data analysis results obtained from current testing,it can be seen that the dynamic stress value of the structure is smaller than the tensile strength of the structure itself,which has limited impact on the stability of the structure.However,as the subway operation years increase,the wear of the track will increase,and the vibration caused will become larger.