路基填筑高液限土工程性质改良

Improvement of Engineering Properties of High Liquid Limit Soil for Subgrade Filling

针对高液限土在实际路基填筑过程中会出现的沉降、开裂、滑坡等问题,分析常用物理和化学改性方法,对沪渝高速公路高液限土路基取土试验,并对掺砂改良进行试验研究,对比分析掺砂前后高液限土的CBR值及含水率等性质,得出:(1)在高液限土中掺加一定量的砂可以改善高液限土自身的不良工程特性,掺砂率在20%左右效果最佳。(2)在CBR值最大时所对应的含水率下进行路基填筑压实,此时含水率略大于最优含水率,接近平衡含水率,后续使用阶段路基的含水率不会发生较大的变化,从而路基的膨胀量不会超出容许范围,保证了路基结构强度值不出现较大的变化。

In view of the settlement,cracking,landslide and other problems in the process of high liquid limited soil in the actual subgrade filling,analyzed common physical and chemical modification methods,soil test of high fluid soil limiting subgrade of Shanghai-Chongqing Expressway,and the experimental study of sand mixing improvement,the CBR value and water content of high fluid limit soil before and after sand mixing are compared and analyzed.It is concluded that:(1)Adding a certain amount of sand to the high liquid limiting soil can improve the adverse engineering characteristics of the high liquid limiting soil itself,sand mixing rate in about 20%of the best effect;(2)Subgrade filling and compaction at the corresponding water content at the maximum CBR value,at this time,the moisture content is slightly greater than the optimal moisture content,close to the equilibrium moisture content.The moisture content of the subgrade will not change greatly in the following use stage,thus,the expansion amount of the subgrade will not exceed the allowable range,ensure that the subgrade structure strength value does not change greatly.