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通过滤纸法试验,测得3种干密度下的土-水特征曲线,拟合得到3种干密度下的Van Genuchten模型参数,分析干密度对土-水特征曲线及Van Genuchten模型参数的影响。通过室内回弹模量试验,分析压实度和含水率对回弹模量的影响,并建立回弹模量与压实度和含水率之间的关系式。基于水力耦合机制,结合试验结果建立地下水位变化作用下的路基湿度及变形的动态响应模型,计算地下水位从-6 m上升到-3 m后,路基的含水率和回弹模量分布以及路基的变形。计算结果表明,干密度对土-水特征曲线Van Genuchten模型参数产生显著影响,饱和体积含水率随着干密度的增大线性减小,残余体积含水率随着干密度的增大线性增大,参数a与进气值的倒数线性相关,参数n随干密度的增大线性增大;回弹模量随着含水率的增大而减小,随着干密度的增大而增大;地下水位上升导致路基土的含水率显著增加,回弹模量明显下降,引起不可忽视的路基变形;不同填筑压实度下,地下水位变化引起的路基变形差异很明显,控制路基土的压实度是提高路基土性能的有效途径。
Through the filter paper test, the soil-water characteristic curves of three kinds of dry densities were measured. The parameters of Van Genuchten model under three kinds of dry densities were fitted and the effects of dry densities on soil-water characteristic curves and Van Genuchten model parameters were analyzed. Through the indoor resilience modulus test, the influence of compaction degree and moisture content on the elastic modulus was analyzed, and the relationship between the elastic modulus and the compaction degree and moisture content was established. Based on the hydraulic coupling mechanism, the dynamic response model of subgrade soil moisture and deformation under the change of groundwater level is established based on the experimental results. After the groundwater level rises from -6 m to -3 m, the water content and the elastic modulus distribution of subgrade and the subgrade The deformation. The calculated results show that the dry density has a significant effect on the Van Genuchten model parameters of soil-water characteristic curve. The saturated volumetric water content decreases linearly with the increase of dry density, and the residual volume moisture content increases linearly with dry density. The parameter a is linearly related to the reciprocal of the intake value. The parameter n increases linearly with the increase of the dry density. The elastic modulus decreases with the increase of the water content and increases with the increase of the dry density. The groundwater As the bit rise, the water content of subgrade soil increases significantly and the rebound modulus decreases obviously, causing the deformation of subgrade which can not be neglected. Under different compaction degree, the difference of subgrade deformation caused by groundwater level change obviously. Degree is an effective way to improve the performance of subgrade soil.