高速公路岩溶路基注浆效果综合评价

Comprehensive evaluation for grouting effect of Karst subgrade of highway

为了对高速公路路基注浆加固效果进行评价,采用注水试验、触探试验、检查孔取芯与孔内电视摄像方法进行检测.注浆后注水试验法检测结果表明,地层透水率都低于47 Lu,能够防止上部软塑状粉质粘土沿溶洞、溶蚀裂隙产生流动与淘空;触探试验结果表明,注浆后不同深度路基承载力的取值fak≥248 kPa;检查孔取芯结果表明,浆液在土体中形成纵横交错浆脉骨架的复合土体能大幅提高土体的强度;钻孔孔内电视摄像结果表明,注浆前土体空隙较大,注浆后土体中的空隙全部被水泥浆脉充填.4种检验方法表明注浆后效果良好,同时也表明综合评价法是评价注浆效果的有效方法,对类似工程具有一定的借鉴与指导意义.

In order to evaluate the grouting reinforcement effect of highway subgrade,the water injection test,cone penetration test,inspection hole coring method and bole hole TV camera were adopted for the detection.The detection results of water injection test method after grouting show that the formation permeability is lower than 47 Lu,which can prevent the flowing and undermining of soft plastic silty clay at the upper part along the cave and corrosion crack.The results of cone penetration test show that the value of bearing capacity fakin the different depth of subgrade after grouting is higher than 248 kPa.The inspection hole coring results show that the grouting in the soil forms a kind of composite soil with the cross grout vein skeleton,which can greatly improve the strength of soil.The results from bole hole TV camera show that the soil gap is bigger before grouting,and will be entirely filled with cement grout vein after grouting.Four test methods reveal that the effect is good after grouting,and the comprehensive evaluation is an effective evaluation way for the grouting effect.The above-mentioned methods have some reference and guidance significance to the similar projects.