基质势作用下非饱和黏性路基土水分迁移规律研究

Study on Water Migration Rule of Unsaturated Viscous Subgrade Soil Under Matrix Potential

基质势在非饱和土水分迁移的过程中起到了主导作用,水分迁移作用对非饱和土路基长期性能的演变具有重要影响,因此研究基质势作用下非饱和黏性路基土水分迁移具有重要的现实意义,基于此选取洪山区典型黏土,开展了非饱和黏性路基土在基质势梯度作用下的水分迁移试验,研究了不同初始含水率,不同含水率梯度,不同迁移时间下路基土水分迁移规律。结果表明,随时间增加土样含水率逐渐增大,基质势逐渐减小,基质势梯度降低水分迁移量减小;土样含水率梯度相同时,基质势梯度随初始含水率增加而减小,水分迁移量减小;初始含水率相同时,基质势梯度随含水率梯度增大而增大,水分迁移量随之增大;基于试验数据,建立了非饱和路基土水分迁移量和初始基质势梯度之间的关系式,二者间大体上呈线性关系。

Matrix potential plays a leading role in the process of water migration in unsaturated soil,which has an important impact on the evolution of long-term performance of unsaturated soil subgrade.Therefore,it is of great practical significance to study the water migration of unsaturated viscous subgrade soil under the action of matrix potential.Based on this,typical clay in Hongshan district was selected.The water migration test of unsaturated viscous subgrade soil under the action of matrix potential gradient was carried out,and the water migration rule of subgrade soil under different initial water content and different water content gradient was studied.Based on the test data,the relationship between the water migration amount of unsaturated viscous subgrade soil and the initial matrix potential gradient was established.The results show that,with the increase of time,the water content of soil sample increases gradually,the matrix potential decreases gradually,and the water migration decreases with the matrix potential gradient.The water migration increases with the increase of matrix potential gradient and water content gradient.Based on the experimental data,the relationship between the moisture migration and the initial matrix potential gradient of unsaturated subgrade soil is established,and the relationship between the two is generally linear.