全风化软质岩改良土铁路路基填料应用研究  

Study of Application of Completely Weathered Soft Rock Improved Soil for Railway Subgrade

作　　者：朱江江[1] 罗强[1] 詹学启[2] 张良[1] 李传宝[2] ZHU Jiangjiang;LUO Qiang;ZHAN Xueqi;ZHANG Liang;LI Chuanbao(Southwest Jiaotong University,Chengdu,Sichuan 610031,China;China Railway Siyuan Survey and Design Group Co.Ltd,Wuhan,Hubei 430063,China)

机构地区：[1]西南交通大学,成都610031 [2]中铁第四勘察设计院集团有限公司,武汉430063

出　　处：《铁道工程学报》2021年第5期25-30,共6页Journal of Railway Engineering Society

基　　金：中铁第四勘察设计院集团有限公司科技研究开发计划项目(2016K27-1);国家自然科学基金项目(51878560)。

摘　　要：研究目的:路基填料的合理选取与应用直接影响施工质量和工程造价。本文依托浩吉重载铁路工程建设,以岳阳至吉安段的全风化软质岩填料为对象,首先通过室内土工试验研究其基本工程性质与改良措施;然后在选取的路基试验段,进行现场填筑试验和长期沉降观测,分析路基填筑施工关键控制参数、碾压工艺以及沉降变形规律;最后开展模拟重载铁路列车荷载长期作用的现场激振试验,测试路堤基床结构的动态响应特征;进而探讨全风化软质岩用作重载铁路基床以下路堤填料的适宜性。研究结论:(1)全风化软质岩为高液限粉质黏土,属于D组填料,用于路堤填筑时应进行改良,水泥改良土的最佳掺配比为3.5%;(2)填料松铺厚度宜取40 cm,含水率按w_(opt)<w<w_(opt)+2%控制时,采用静压2遍+弱振1遍静压1遍+强振1遍静压1遍的碾压组合方式,路基压实质量可满足规范要求;(3)路基工后沉降以及动荷载作用下路基动态性能指标均满足重载铁路设计要求,路堤基床结构具有良好的动力稳定性,全风化软质岩水泥改良土填料可用于重载铁路基床以下路堤填筑;(4)该研究结果可为完善重载铁路路基的设计和施工技术提供借鉴和参考。Research purposes:The reasonable selection and application of subgrade filler directly affects the construction quality and project cost.This paper relies on the construction of Haolebaoji-Ji’an heavy haul railway project,and takes the completely weathered soft rock filler from Yueyang to Ji’an section as the object.Firstly,the basic engineering properties and improvement measures are studied by laboratory geotechnical tests;Then,the field filling test and long-term settlement observation are carried out in the selected subgrade test section,and the key control parameters and rolling technology,settlement deformation law of subgrade filling construction are analyzed;Finally,the field excitation test is carried out to simulate the long-term action of heavy haul railway train load to test the dynamic response characteristics of embankment foundation bed structure;Furthermore,the suitability of completely weathered soft rock as embankment filling material under heavy haul railway subgrade bed is discussed.Research conclusions:(1)The completely weathered soft rock is high liquid limit silty clay,which belongs to group D filler,it should be improved when used for embankment filling,the best mixing ratio of cement improved soil is 3.5%.(2)The thickness of the filling loose paving should be 40 cm,when the moisture content is controlled according to w_(opt)<w<w_(opt)+2%,and the combination of static pressure 2 times+weak vibration 1 time static pressure 1 time+strong vibration 1 time static pressure 1 time is adopted,the compaction quality of the subgrade can meet the requirements of the code.(3)The post construction settlement and the dynamic performance index of subgrade under dynamic load all meet the design requirements of heavy haul railway,and the subgrade bed structure of embankment has good dynamic stability,the completely weathered soft rock cement improved soil filler can be used for embankment filling under the subgrade bed of heavy haul railway.(4)The research results can provide reference for improving t

关 键 词：重载铁路路基 全风化软质岩 水泥改良土 工程性质 碾压工艺 沉降变形规律 动态特性 

分 类 号：TU433[建筑科学—岩土工程]