桥址岸坡凸出部地震影响评价及墩台位置优化  

Seismic Impact Evaluation of the Convex Part of the Bridge Bank Slope and Optimization of Pier and Abutment Position

作　　者：吴加红 赵强 秦辉 尹国华 WU Jiahong;ZHAO Qiang;QIN Hui;YIN Guohua(Yunnan Transportation Development Investment Co.,Ltd.,Kunming,Yunnan 650000,China;Yunnan Menglyu Expressway Investment and Development Co.,Ltd.,Pu'er,Yunnan 665000,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,Hubei 430071,China;Zhaotong Yizhao Expressway Investment Development Co.,Ltd.,Zhaotong,Yunnan 657000,China)

机构地区：[1]云南省交通发展投资有限责任公司,云南昆明650000 [2]云南勐绿高速公路投资开发有限公司,云南普洱665000 [3]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [4]昭通市宜昭高速公路投资开发有限公司,云南昭通657000

出　　处：《公路工程》2024年第1期39-44,共6页Highway Engineering

基　　金：云南省交通科技项目(云交科教便〔2020〕74号);交通运输部科技示范项目(2017-09)。

摘　　要：凸起边坡场地的地形地震影响性评价对工程稳定性尤其重要。依托特大桥桥址边坡案例,利用极限平衡法和有限元数值模拟方法,研究了考虑风化带影响的凸出部在不可变水平地震放大系数(规范方法)和可变水平地震放大系数分别作用下,边坡稳定性和变形随临坡距离变化关系。研究结果表明:①考虑风化带影响的凸出部受到地震放大作用影响较大的是强风化带,而中微风化带受地震放大效应影响较小。②当临坡距离为23 m时,满足地震稳定性,且考虑风化带影响的凸出部在不可变水平地震放大系数(规范方法)和可变水平地震放大系数作用下稳定性系数变化趋势较一致。③为保证该桥址边坡开挖地形的地震稳定性,墩台外侧距离坡面距离不小于15~23 m,若选择低值需采取强加固措施,选择高值可采取一般处置措施。为考虑风化带的凸出地形的高陡边坡桥位地震工况设计提供一定指导。The topographic and seismic impact evaluation of the raised slope site is particularly important for the stability of the project.Based on the case of the bridge site slope of a super-large bridge,the relationship between the slope stability and deformation and the distance from the slope was studied by using the limit equilibrium method and the finite element numerical simulation method,which considered the action of the invariable horizontal seismic amplification coefficient(code method)and the variable horizontal seismic amplification coefficient,respectively.The results show that:①Considering the influence of weathered zone,the bulge is greatly affected by seismic amplification,while the moderately weathered zone is less affected by seismic amplification.②When the distance from the slope is 23 m,the seismic stability is satisfied,and the variation trend of the stability coefficient of the bulge considering the influence of weathered zone is consistent under the action of the constant horizontal seismic amplification coefficient(standard method)and the variable horizontal seismic amplification coefficient.③In order to ensure the seismic stability of the excavated terrain of the slope of the bridge site,the distance from the outer side of the main pier cap to the slope surface should be no less than 15~23 m.If the low value is selected,strong reinforcement measures should be taken,and if the high value is selected,general disposal measures can be taken.It can provide some guidance for the seismic design of high and steep slope bridge site considering the protruding terrain of weathered zone.

关 键 词：高边坡 风化带 凸出部 地震放大效应 墩台位置优化 

分 类 号：U442.55[建筑科学—桥梁与隧道工程]