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马万荣，刘渊，刘祥

（ 广西路桥工程集团有限公司，广西 南宁 530200)

摘 要：为探究基覆型边坡的动力响应特性、破坏模式以及基覆界面倾角的影响， 以西南山区某基覆型边坡为原型，利用FLAC3D软件模拟基覆型边坡在地震作用下的响应过程，分析不同地震作用下边坡的动力响应及破坏模式，在此基础上进一步改变基覆界面的上、下界面倾角，分析基覆界面倾角对动力响应特性及破坏模式的影响。结果表明：基覆型边坡的PGA放大系数沿坡表方向随高程增大先增大后减小，坡体内部的动力响应呈现明显的高程效应和趋表效应规律，且随着输入PGA增大而减小；在地震作用下边坡沿上覆土体内部形成的潜在滑动面发生剪切破坏，加载PGA=0. 6g的EL波和Kobe波时，坡表的最大位移分别为228.1cm和446.2cm, 加载Kobe波时模型的加速度响应与位移响应均要比加载EL波时更激烈；基覆界面倾角对动力响应特性及破坏模式有着显著影响，当上界面倾角增大时，坡表处动力响应程度有所增强，而下界面倾角增大时， 坡表处动力响应程度有一定减弱，边坡破坏模式随着上下界面倾角差值增大由整体滑移破坏逐渐转变为局部滑 移破坏，上下界面倾角差值越大，边坡稳定性越高。

关键词：基覆型边坡；地震作用；数值计算；动力响应；破坏模式；界面倾角

中图分类号：U213.1+3 文献标志码：A

文章编号：1005-8249(2024)03-0079-07

DOI：10. 19860/j.cnki.issn1005 - 8249.2024.03 .016

MA Wanrong , LIU Yuan , LIU Xiang

(Guangxi Road and Bridge Engineering Group Co. ，Ltd. ，Nanning 530200 , China)

Abstract : In order to investigate the dynamic response characteristics , damage modes and the influence of base - cover interface inclination angle of a base - cover slope in the southwest mountainous area , FLAC 3D software is used to simulate the response process of base - cover slope under seismic action , and to analyze the dynamic response and damage modes of the slope under different seismic actions , and then to further change the inclination angle of the base - cover interface , and to analyze the effect of the inclination angle on the dynamic response characteristics and the damage modes. On this basis , we further change the inclination angle of the upper and lower interfaces of the base - cover interface to analyze the influence of the inclination angle of the base - cover interface on the dynamic response characteristics and damage mode. The results show that the PGA amplification coefficient of the slope of bedrock and overburden layer increases and then decreases with the increase of ELevation , and the dynamic response of the internal slope body shows a clear pattern of ELevation effect and surface effect , and decreases with the increase of input PGA. The maximum displacement of the slope surface is 228. 1 cm and 446. 2 cm when loading EL and Kobe waves with PGA = 0. 6g. The accELeration response and displacement response of the model are more intense when loading Kobe waves than when loading EL waves. The slope damage mode gradually changes from overall slip damage to local slip damage as the difference between the upper and lower interface inclination increases , the slope failure mode gradually transitions from overall slip failure to local slip failure , and the greater the difference , the higher the slope stability.

Keywords : the slope of bedrock and overburden layer; earthquake; numerical calculation; dynamic response; failure mode; interface dip

作者简介： 马万荣 (1973—) , 男 ，本科 ，高级工程师 ，研究方向：公路工程相关施工管理。

通信作者：刘 祥 (1991 —) , 男 ，博士 ，高级工程师 ，研究方向： 结构工程 、抗震减灾以及项目施工管理。

收稿日期：2023- 10- 19