非饱和黏土质砂的渗气规律试验研究

为了探讨非饱和黏土质砂的渗气规律，对常规三轴仪进行了改造，使其能够进行非饱和土渗气性量测，改进后的渗气装置具有构造简单、制样方便、试样均匀性好、加载系统稳定、可用量测的气压力梯度范围较大、提高了量测精度等优点，并解决了量测空气体积困难的问题和渗气试验气体从刚性壁和试样边缘流出的问题。使用该套仪器研究了不同干密度和不同含水率条件下气体流速与渗透系数随压力梯度变化的规律，分析了气体流速、渗气系数同含水率和干密度之间的依存关系，建立了渗气系数与含水率和干密度之间的函数关系。研究结果表明：试样在所研究的含水率、干密度范围，非饱和黏土质砂中气体流动可用达西定律描述。

Experimental study of gas permeability of unsaturated clayey sand

In order to understand factors affected gas permeability of unsaturated clayey sand, through rebuilding triaxial apparatus, it can be used to measure gas permeability of unsaturated soils. The modified apparatus has advantages as follows: such as structure simpleness, making model expediency, good model uniform, stable loading system, comprehensive measuring pressure gradient, enhancing measuring precision. And it resolves problems that measuring gas volume no easy. At same time it resolves a problem that gas flow out rigid wall and model edge. The relationship between flowing velocity and coefficient of permeability is given by that apparatus, under different dry densities and different water contents. Flowing velocity of unsaturated soils can be expressed by Darcy law under the range of water content and dry density in this test. The function of gas coefficient of permeability, water content and dry density are given from a great deal of test data.