基于时域边界元的跨海桥梁下部结构波浪荷载计算方法  

Investigation of Wave Loads on Deep-Water Bridge Pier Based on Time-Domain Boundary Element Method

作　　者：王东辉 潘俊志[3] 遆子龙 WANG Dong-hui;PAN Jun-zhi;TI Zi-long(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China;China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China;Department of Bridge Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044 [2]中铁大桥局集团有限公司,湖北武汉430050 [3]西南交通大学桥梁工程系,四川成都610031

出　　处：《桥梁建设》2022年第6期66-72,共7页Bridge Construction

基　　金：国家自然科学基金项目(52008349);四川省自然科学基金项目(2022NSFSC1163)。

摘　　要：为解决当前波浪荷载数值模拟计算量大、效率低的问题,提出桥梁下部结构波浪荷载的时域边界元计算方法。该方法通过选取合适的格林函数,将计算域由三维流域降维为水面和结构物面,采用四边形单元对水面和结构物面进行离散,建立边界元积分方程,并在时域下逐步求解结构表面的波压力,随后对波压力进行积分,计算结构波浪力。为验证该方法的正确性,将该方法计算结果与Maccamy圆柱波浪力理论解进行比较,并以平潭海峡公铁大桥为背景,对该桥非通航孔桥下部结构的施工钢围堰进行波浪荷载模拟,与现场波压力监测数据进行对比。结果表明:波浪荷载时域边界元计算方法在保证精度的同时,计算效率较高;该方法在实际工程中有较好的适用性;绕射效应对围堰的波压力大小与分布规律有显著影响,在设计阶段应予以充分考虑。The current wave load modeling methods often incorporate daunting computing work and the computing efficiency is beyond satisfaction.In this paper,a time-domain boundary element method to compute wave loads on bridge substructure is presented.An appropriate Green′s function is quite critical in this method,where the computing domain needs to be dimensionally reduced from a three-dimensional watershed to a water surface and a structure surface,which in turn are discretized by the quadrilateral elements to establish a boundary element integral equation.Subsequently,wave pressures on the surfaces of the structure are calculated in time domain step by step,and the pressures are integrated to derive the wave forces.To verify the effectiveness of the method,the computing results are compared with the theoretical solution of Maccamy formulation.The presented method was employed to simulate the wave loads on the steel cofferdam of the case bridge,the non-navigation channel bridge of Pingtan Straits Rail-cum-Road Bridge,and the results were compared with the on-site monitored wave pressures.It is concluded that the wave load computing method developed from the time-domain boundary element method can ensure the required computing precision,as well as high computing efficiency.The method is verified applicable to real projects.In addition,the diffraction effect can trigger significant variation of wave pressure intensity and distribution,which should be given great concern in the design stage.

关 键 词：跨海桥梁 下部结构 波浪荷载 时域边界元方法 计算方法 数值模拟 

分 类 号：U443.2[建筑科学—桥梁与隧道工程] U441.2[交通运输工程—道路与铁道工程]