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路基边坡雨水浸透变形模拟研究

2021-09-18冯振华,王利超,韩玉龙

河北工业科技 2021年5期

冯振华,王利超,韩玉龙

摘要:为了减少由于雨水渗透引起的路基边坡局部变形和失稳现象,在概述模型实验现象的基础上,采用饱和及非饱和渗流分析方法以及弹塑性有限元分析方法,模拟路基边坡模型中水位的变化和滑动破坏发生前的初始变形,建立渐进式边坡失稳的预测方法,通过实验进行再现分析,以明确边坡初始变形机理。研究结果表明:1)在饱和及非饱和渗流模拟中,当渗流系数设置值比渗透实验结果大时,模型实验的再现性良好;2)在弹塑性有限元分析中,通过边坡水位升高导致变形系数(刚度)减小,进而能够分析出模型实验中边坡的初始变形。研究过程为分析降雨期间路基边坡稳定性提供了新方法,其结果可为工程施工过程中避免发生大规模崩塌现象采取适当措施提供依据,为施工标准的设计和制定提供重要参考。

关键词:岩土工程;降雨模型实验;初始变形;饱和及非饱和渗流分析;弹塑性有限元分析

中图分类号:TU45文献标识码:ADOI: 10.7535/hbgykj.2021yx05004

Simulation research on rainwater infiltration deformation of

roadbed slope

FENG Zhenhua,WANG Lichao,HAN Yulong

(Henan Transportation Planning and Design Institute Company Limited,Zhengzhou,Henan 450000,China)

Abstract:In order to reduce the local deformation and instability of subgrade slopes caused by rainwater infiltration,on the basis of an overview of the model experiment phenomena,the saturated and unsaturated seepage analysis and the elastoplastic finite element analysis were used to simulate the change of water level in the roadbed slope model and the initial deformation before sliding failure.Then the progressive slope instability prediction method was established.Finally,through the reconstruction analysis of the rules with experiments,the initial deformation mechanism of the slope was clarified.The results show that:1) in saturated and unsaturated seepage simulations,when the seepage coefficient is set larger than the result of the seepage test,the reproducibility of the model experiment is good;2) in the elastoplastic finite element analysis,the deformation coefficient (stiffness) can be reduced by increasing the water level of the slope,thereby the initial deformation of the slope in the model experiment can be analyzed.The study provides a new way for analyzing the stability of roadbed slopes during rainfall,and the results can provide a reference for taking appropriate construction measures to prevent the occurrence of large-scale collapse,which is also beneficial for formulating future construction standards.

Keywords:geotechnical engineering;rainfall model experiment;initial deformation;aturated and unsaturated seepage analysis;lastoplastic finite element analysis

河南地區每年7—9月为雨季,近年来大部分地区中雨、大雨以及暴雨日数呈增加趋势,自然灾害频繁。极端降水会引起路基土体结构变形、坍塌,对公路路基影响巨大,严重影响交通运输安全。

豫东地区土质多为粉质砂土,降雨过程中边坡土体结构破坏的状况主要通过模型实验进行分析,确定边坡的稳定性[1-3]。对降雨过程中边坡水位变化和崩塌机理的研究发现,粉质砂土边坡的稳定性分析大多基于完全刚塑性体的极限平衡假设。……

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