黑方台黄土的水力特性研究

由于长期农业灌溉,在甘肃黑方台地区的黄土塬边发生了严重的滑坡灾害。针对以上问题,本文选取黑方台黄土作为研究对象。首先,测试了该地区黄土的基本物理性质,在此基础上,重点研究了该地区黄土的水力特性。一方面,通过在现场开展双环注水试验,测得了不同位置的渗透系数,另一方面,利用原状土样,开展了增减湿循环条件下的土水特征曲线测试。将实验室测得的原状黄土土水特征曲线离散点,利用MATLAB实现了参数拟合。结合黄土的微观结构特性,对黄土的渗透系数和土水特征进行了进一步讨论。结果表明,虽然该黄土具有粉土的颗粒级配,但是其结构特性使其表现出较高的渗透系数和较低的进气值。

Study on the Hydraulic Properties of Heifangtai Loess

The long-term agricultural irrigation has induced serious landslide disasters at the edge of the Heifangtai Plateau in Gansu Province. The Heifangtai loess is selected for testing in this study. Firstly, the basic physical properties of the loess were tested. Then this paper focuses on the hydraulic properties of the loess. In one aspect, the coefficient of permeability at different places was measured through conducting in-situ double-ring tests. In another aspect, the soil-water characteristic curves were tested using an undisturbed specimen, including both wetting and drying paths. The scattered points measured in the test were best-fitted using MATLAB. Combined with the microscopic structural feature of loess, the coefficient of permeability and soil-water characteristic were further discussed. Though the loess shows the particle size distribution of silt, it has high coefficient of permeability and low air-entry value due to its structural feature.