摘要
满足一般路基要求在稳定的第四系堆积体上的低路堤在运营中出现了变形破坏,以饱和与非饱和渗流理论、FREDLUND非饱和土双应力变量强度理论为基础,建立路堤填筑前后计算模型,分析了四川阆中沟溪村某道路工程一段第四系堆积体路堤填筑前后的稳定性。研究结果显示,路线通过处第四系堆积体地质条件简单,原始斜坡在最不利的降雨工况下也保持了稳定,路堤填筑高度仅4 m,符合一般路基的要求;堆积体路堤在最不利降雨工况下随着降雨过程稳定性系数不断降低,当降雨达到11 h,稳定性系数小于1.0,此时路堤发生破坏,与路基失稳破坏的现象一致。在山区公路建设过程中,稳定的第四系堆积体上填筑低路堤虽然满足路基设计规范对一般路基的要求,不需要进行单独验算,但在长期降雨作用下其稳定性会持续降低,极可能出现失稳破坏。因此,在工程设计与施工中应当验算其长期降雨作用下的稳定性,以保证工程的安全。
The low embankment on the stable Quaternary deposits that meets the requirements of the general subgrade has been deformed and destroyed in operation.Based on the saturated and unsaturated seepage theory and the dual-stress variable strength theory of FREDLUND unsaturated soil,the calculation model before and after the embankment filling was established,and the stability of the Quaternary deposits before and after the embankment filling of a road project in Gouxi Village,Langzhong City,Sichuan Province was analyzed.The research results show that the geological conditions of Quaternary deposits where the route passes are simple,and the original slope also remains stable under the most unfavorable rainfall conditions,and the embankment filling height is only 4 m,which meets the requirements of general subgrade.Under the most unfavorable rainfall conditions,the stability coefficient of the accumulation embankment decreases with the rainfall process.When the rainfall reaches 11 hours,the stability coefficient is less than 1.0,and the embankment is damaged,which is consistent with the phenomenon of instability and failure of the subgrade.In the process of highway construction in mountainous area,although filling low embankment on stable quaternary accumulation body meets the requirements of subgrade design code for general subgrade and does not need to be checked separately,its stability will continue to decrease under the action of long-term rainfall,which is likely to cause instability and failure.Therefore,the stability under long-term rainfall should be checked in engineering design and construction to ensure the safety of the project.
作者
廖军
邓涛
周越良
龚洪苇
冯文凯
LIAO Jun;DENG Tao;ZHOU Yue-liang;GONG Hong-wei;FENG Wen-kai(College of Environment and Civil Engineering, Chengdu University of Technology, Chengdu 610059,China;Laboratory of Geohazard Prevention and Geoenvironment Protection of Chengdu University of Technology, Chengdu 610059, China)
出处
《科学技术与工程》
北大核心
2021年第23期10090-10097,共8页
Science Technology and Engineering
基金
国家自然科学基金(41977252)
地质灾害防治与地质环境保护国家重点实验室自主研究课题(SKLGP2020Z001)。
关键词
第四系堆积体
降雨作用
局部暂态饱和区
数值模拟
路堤稳定性
Quaternary accumulation
rainfall effect
local transient saturation zone
numerical simulation
embankment stability
