川藏铁路路基红层泥岩改良填料试验及施工压实技术研究  

Experiment and Compaction Technology Study on Improved Filler of Red Mudstone in Sichuan-Tibet Railway

作　　者：徐华[1] Movahed MA 游关军 王歆宇 任伟彰 Xu Hua;Movahed MA;You Guanjun;Wang Xinyu;Ren Weizhang(School of Civil Kngineering,Southwest Jiaotong University tChengdu Sichuan 610031,China;Sinohydro Bureau 5^th Engineering Co.Lid.,Chengdu Sichuan 610066,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中国水利水电第五工程局有限公司,四川成都610066

出　　处：《铁道建筑技术》2019年第10期12-17,共6页Railway Construction Technology

基　　金：“十三五”国家重点研发计划(2016YFB1200401-102D);中铁二院工程集团有限责任公司科技项目[KYY2018014(18-19)]

摘　　要：针对川藏铁路成雅段沿线富水红层黏土路基含水率高、无法压实等问题,在原状红层黏土中掺入一定粒径配比的弱风化红层泥岩碎石改良填料,通过室内物理力学性质试验,确定了原状土与泥岩碎石的质量比例为1∶1和2∶3的两种改良填料.采用现场施工试验,测定两种改良填料的地基系数K30、压实系数K和孔隙率n,探索合理的现场施工压实技术方案.研究结果表明:(1)改良填料1和2均级配良好,属于B组填料;(2)改良填料1相比改良填料2具有较高的最大干密度(2.22 g/cm3)和较低的最优含水率(10.26%);(3)随着含水率的增加改良填料的无侧限抗压强度逐渐降低,在最优含水率和压实系数为0.95时,改良填料1和2的无侧限抗压强度分别为424.1kPa和219.1 kPa,均满足规范要求;(4)推荐施工压实技术方案为,在虚铺厚度为35 cm时,20t压路机的合适碾压方式为先静力碾压1遍,然后微振动碾压1遍,最后强振动碾压6遍;经现场测试,各项指标均满足规范要求,能较好地应用于基床底层以下的路堤填筑.To solve the problems of high-water content and uncompaction of red clay in rich water area,which used in subgrade construction of Chengdu to Ya'an section of Sichuan-Tibet Railway,the improved subgrade fillers were made by mixing original red clay with specific particle graded weakly weathered red-mudstone gravel.Two kinds of improved subgrade fillers with the ratio of red clay to red-mudstone is 1:1 and 2:3,which were determined through laboratory test of physical and mechanical properties.The foundation coefficient the compaction coefficient K and the porosity n of two kinds of improved fillers were measured by field tests,and a reasonable construction scheme of compaction was explorer!.Researches show that;(1)the gradation of the improved filler 1 and the improved filler 2 are good,which belong to filling material of Group B.(2)for the two improved fillers,the improved filler 1 presents a better compaction characteristic of larger maximum dry density of 2.22 g/cm^3 and smaller optimum w-ater content of 10.26%.(3)With the increase of water content,the unconfined compressive strength of the improved fillers decreases gradually.The uuconfined compressive strength values of the improved filler 1 and 2 are 424.1 kPa and 219.1kPa respectively when the fillers are at the optimum water content and compaction coefficient is of 0.95.(4)Recommended construction scheme of compaction is proposed.W hen lay-down thickness is 35 cm,the suitable method of rolling for 20t roller is static pressure one time then micro-vibration one time and stong-vibra-tion rolling six times at last.In-situ test results indieate that the improved fillers meet the requirement of the railway subgrade construction,and the fillers can 1m*applied to the filling of the embankment below the InUtom layer of the subgrade bed.

关 键 词：铁路路基 红层泥岩 改良填料 地基系数K30 压实系数K 

分 类 号：U213.1[交通运输工程—道路与铁道工程]