膨胀土胀缩变形与渗透性规律试验研究

大气和地下水共同影响下,膨胀土路基或边坡工程在一定深度范围内将出现明显的干缩湿胀变形,其渗透性能也会出现显著变化,并进一步诱发膨胀土路基或边坡的失稳破坏。为系统研究竖向荷载和干湿循环作用下膨胀土胀缩变形与渗透性能变化规律,采用温控气压固结渗透仪分别进行不同荷载和干湿循环作用下的膨胀、收缩与渗透试验,研究膨胀土在不同荷载和干湿循环条件下的胀缩变形规律,确定膨胀土水渗透系数和气渗透系数变化规律。研究成果能够用于确定膨胀土容许胀缩变形量和容许竖向荷载,提出明确的膨胀土路基或边坡的最小防护深度和限制荷载,优化膨胀土路基和膨胀土边坡设计方案。

Swelling-shrinkage deformation and permeability trends of expansive soil

Under the influence of atmospheric environment and underground water, expansive soil roadbed or slope in a certain depth will generate obvious dry shrinkage and wet swelling deformation, inducing obvious change of expansive soil permeability, which further induces the destruction of expansive soil roadbed or slope. In order to systematically study the change of swelling and shrinkage deformation and permeability of expansive soil under the action of wet-dry cycling and vertical load, the swell-shrink deformation and permeability test under the action of different loads and wet-dry cycling was carried out by the thermostatic pressure permeation consolidometer. The swelling-shrinkage deformation laws of expansive soil under different loads and wet-dry cycling were studied, and the variations of water permeability coefficient and gas permeability coefficient were determined. The research results can be used to determine the allowable swelling-shrinkage deformation and vertical load of expansive soil, the minimum protection depth and limited load of expansive soil roadbed or slope for optimizing the design of expansive soil roadbed or slope.