基床表层级配碎石注浆改良模型试验  

Model test on grouting improvement of graded gravel in surface layer of subgrade

作　　者：聂志红[1] 刘源[1] 罗承平[2] 王翔[1] 

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中铁一局集团有限公司,陕西西安710054

出　　处：《长安大学学报（自然科学版）》2015年第4期48-53,共6页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学高铁联合基金项目(U1134207)

摘　　要：为了解决寒冷地区铁路客运专线路基的冻胀问题,利用注浆泵与真空泵联合对路基级配碎石大比例模型进行注浆试验,获取注浆参数,通过电镜扫描、渗透试验、冻融循环试验验证注浆改良级配碎石冻胀性的效果。研究结果表明:试验浆液的粘度为2.50 MPa·s时,其可灌性满足注浆要求;注浆后的级配碎石与浆液粘结情况良好,其渗透系数由6.8×10-3 cm/s降为1.4×10-10 cm/s,级配碎石改良后的渗透性显著降低;在30次冻融循环作用下,注浆改良后的级配碎石最大冻胀率为0.25%,其冻胀性满足铁路客运专线路基不均匀变形要求;模型试验验证了注浆能够有效改善级配碎石的渗透性与冻胀率,为基床表层级配碎石的现场注浆试验提供了参考依据。In order to solve the frost heave problem in subgrade of passenger dedicated line in cold region, a graded gravel model was grouted by using grouting pump and vacuum pump to obtain the grouting parameters. Electron microscope scanning, penetration test and freeze-thaw cycle test were carried out to verify the frost heave effect of graded gravel after grouting improvement. The results show that when the viscosity of slurry reaches to 2.50 MPa ~ s, the groutability of slurry can meet the requirement of grouting test. The graded gravel after grouting is well bounding with the slurry and the permeability of the samples decreases from 6.8 X 10-~ cm/s to 1.4 X 10-1~ cm/s. The permeability of graded gravel reduces significantly after grouting improvement. The maximum frost heave ratio is 0.25o/6o, which meet the requirement of the uneven deformation in subgrade of passenger dedicated line. The model test demonstrates that the permeability and frost heave ratio can be effectively improved by grouting, which provides a reference for field grouting test of graded gravel in surface layer of subgrade. 3 tabs, 7 figs, 10 refs.

关 键 词：道路工程 级配碎石 模型试验 注浆改良 渗透性 冻胀 

分 类 号：U416.1[交通运输工程—道路与铁道工程] TU433[建筑科学—岩土工程]