砂性土地层的注浆加固试验研究

Experimental Research on Grouting Reinforcement Characteristics of Sandy Soil Layer

针对浅表砂性土层条件下的井筒施工难题,以内蒙古鄂尔多斯地区的砂性土地层为工程背景,对砂性土层的注浆加固进行了试验研究。运用正交原理,按3因素5水平设计试验方案,测定了不同含水率、浆砂比以及养护时间条件下砂性土注浆固结体的抗压强度、抗拉强度、黏聚力及内摩擦角,分析了3个因素与砂性固结体力学性质间的相关规律。研究结果表明:当含水率为3.4%、浆砂比为1∶4、养护时间为4d时,固结体的力学性能达到最优,各因素对固结体力学性质影响的程度从大到小依次为:含水率、浆砂比、养护时间,且随着含水率的增大,固结体的抗压强度、抗拉强度及黏聚力减小,浆砂比与内摩擦角成反比。

Aiming at the difficulties of shaft construction under the conditions of shallow sandy soil,taking the reinforcement of the main and auxiliary shafts in Ordos area,Inner Mongolia as the engineering background,grouting reinforcement of sandy soil was studied by test.The experiment plan was designed according to three factors and five levels of the orthogonal principle.Then,the compressive strength,tensile strength,cohesion and the internal friction angle of the sandy soil grouting consolidated body were measured under different water contents,mortar-sand ratios and curing time.The correlation between the three factors and the mechanical properties of sandy consolidated body was analyzed.The study results indicate that when the water content is 3.4%,the mortar-sand ratio is 1∶4,and the curing time is 4 days,the mechanical property of the consolidated body is the optimal.The influence degree of various factors on the mechanical properties of the consolidated body is water content>mortar-sand ratio>curing time.When the water content increases,the compressive strength,tensile strength and cohesion of the consolidated body decrease,and the mortar-sand ratio is inversely proportional to the internal friction angle.