非饱和土路基水气迁移规律及其影响因素实验

非饱和黏土的水气迁移影响着路基服役期间的安全运行和长期使用性能的保障。研究非饱和土路基水气迁移规律对路基路床湿度的影响具有重要的工程应用价值和意义。本文通过室内试验模型,运用高低温交变恒温箱改变环境温度,模拟四季环境温度对水分迁移的影响。模拟非饱和黏性土气态水迁移过程,并进行影响因素的敏感性分析。获得非饱和黏性土的水气迁移规律并进行影响性因素评价,实验结果表明,非饱和土水气迁移过程中,含水率梯度对气态水迁移量影响较大；迁移时间对液态水迁移影响较大；低温环境下以液态水迁移为主,随环境温度升高气态水迁移量占比逐渐升高。含水率梯度,含水率水平,压实度,迁移时间,不同环境温度均对气态水迁移量均有贡献,其中压实度对其影响最小。在实际工程中应更重视水气两相迁移对路基土体性能的影响。

Experimental study on the law of water vapor migration and its influencing factors in unsaturated soil subgrade

The water vapor migration of unsaturated clay affects the safe operation of the subgrade during service and the guarantee of long-term performance. It is of great engineering application value and significance to study the influence of water vapor migration law on unsaturated soil subgrade moisture on subgrade subgrade humidity. In this paper, through the indoor test model, the high and low temperature alternating incubator is used to change the ambient temperature to simulate the effect of ambient temperature on water migration in four seasons. The migration process of gaseous water in unsaturated cohesive soil is simulated, and the sensitivity analysis of influencing factors is carried out. The water vapor migration law of unsaturated cohesive soil is obtained and the influencing factors are evaluated. The experimental results show that in the process of water vapor migration in unsaturated soil, the water content gradient has a great influence on the gaseous water migration; the migration time has a great influence on the liquid water migration. Larger; under low temperature environment, the migration of liquid water is dominant, and the proportion of gaseous water migration gradually increases with the increase of ambient temperature. Water content gradient, water content level, degree of compaction, migration time, and different ambient temperatures all contribute to the migration of gaseous water, of which the degree of compaction has the least effect. In practical engineering, more attention should be paid to the influence of water-gas two-phase migration on the performance of subgrade soil.