闽南山区薄壁空心高墩稳定性分析

STABILITY ANALYSIS OF THIN-WALLED HOLLOW HIGH PIERS IN THE MOUNTAINOUS AREA OF SOUTHERN FUJIAN

为研究闽南山区薄壁空心高墩稳定性,以莆炎高速公路下坂1号大桥为依托,采用有限元分析软件Midas-Civil建立薄壁空心高墩三维仿真模型,考虑实际荷载工况,分析高墩第一类、第二类稳定安全系数,并探究混凝土强度、横隔板、墩高对高墩稳定性的影响。结果表明第一类稳定安全系数随阶数线性变化,第一类稳定安全系数25.27,大于规范要求的安全系数4;考虑非线性因素后,高墩的稳定安全系数出现了降低。横隔板数量、混凝土强度等级对高墩稳定性的增加幅度影响有限,不应通过增加横隔板数量与提高混凝土强度等级的方式提高高墩的稳定性;高墩前3阶稳定安全系数随墩高的增大而快速减小,墩高是对稳定性的影响程度相较于横隔板数量、混凝土强度等级更大。研究成果可供同类工程施工参考。

Taking a project in No.1 Xiaban Bridge of Puyan Expressway as the case,the stability of thin-walled hollow high piers in the mountainous area is studied.The finite element analysis software Midas-Civil is used to establish a three-dimensional simulation model of thin-walled hollow high piers.Considering the actual load conditions,the first and second stability safety factors of high piers are analyzed,and the influence of concrete strength,diaphragm,and pier height on the stability of high piers is explored.The results show that the stability safety factor of the first type changes linearly with the order,and the stability safety factor of the first type is 25.27,which is greater than the safety factor of 4 required by the specification.After considering nonlinear factors,the stability safety factor of high piers decreases.The number of diaphragms and the strength grade of concrete have limited influence on the stability of high piers.The stability of high piers should not be improved by increasing the number of diaphragms and the strength grade of concrete.The first three order stability safety factors of high piers decrease rapidly with the increase of pier height.The pier height has a greater impact on the stability than the number of diaphragms and the strength grade of concrete.The research results can be used as the reference for similar projects.