针对绵广高速公路路基病害压力注浆处治工程,采用现场调查测试、离心模型试验以及数值仿真对压力注浆处治路基病害的工艺过程及影响因素进行了研究。揭示斜坡路基断面几何异型是导致路基不均匀沉降的主要原因,并进而导致路面出现纵向开裂。离心模型试验表明:注浆方式宜采用2次注浆法,第1次注浆压力为0.2MPa,第2次注浆压力控制在0.4-0.5MPa;注浆孔的合理间距推荐为2.0m;工程实际中应兼顾经济性,选择合理的浆液配合比和养护时间。数值仿真结果表明:压力注浆包括应力累积、裂纹延伸和裂缝扩张3个阶段,土体劈裂所需要的压力随均质度及土体强度的提高而增大。
In the practice of pressure grouting in subgrade retrofitting project of Mianyang- Guanyuan Highway, field monitoring, centrifugal model test and numerical simulation were carried out to study the technical process and the influencing factors of pressure grouting in subgrade disease. It is revealed that the geometrical property of subgrade section is the main reason to the differential settlement of subgrade, and then produces pavement premature failure such as longitudinal cracking. Centrifugal model test indicates that two-phase grouting method that with 0.2 MPa at the first stage and 0.4-0.5 MPa at the second stage is recommended. The recommended reasonable space between grouting holes is 2.0 m. Economy should be considered in the practice for choosing reasonable concrete mix proportion and maintenance time. Numerical L result shows that there are three stages for pressure grouting, such as stress ion stage, cracking extension stage and crack widening stage. The pressure for soil acreases with the increases of homogeneity and soil strength. 3 tabs, 19 figs, 18 refs.