干湿循环对合肥马鞍山路膨胀土强度特性的影响

Influence of drying and wetting cycle on strength characteristics of expansive soil in Ma'anshan Road in Hefei

膨胀土属高塑性黏土,是一种典型的非饱和土,性质极不稳定,其吸水膨胀、失水收缩、干缩裂隙发育等特性常常使建筑物产生不均匀的胀缩变形,造成在膨胀土地基上的建筑物位移、开裂、倾斜,甚至破坏,是一种典型的工程灾害性地质土。另外,膨胀土边坡也常由于雨水的作用失稳,造成不必要的损失。近年来,对膨胀土的强度和变形特性的研究已成为热点。其最大的特点是:在季节气候的影响下其强度特性具有明显的规律变动。通过模拟土体季节性的干缩湿胀,测定其自由膨胀率、液塑限、抗剪强度和无侧限抗压强度,并与掺入7%石灰后的改良土的试验数据及其他试验资料对比,探讨干湿循环效应对膨胀土强度的影响。

As a high plasticity clay, expansive soil was a typical non-saturated soil, and its nature was very unstable. Its water expan- sion, contraction water loss, shrinkage cracks and other characteristics made buildings often have uneven expansion and contraction de- formations, resulting in expansive soil displacement, cracking, tilt or even destroy for buildings. It was a typical engineering disaster geological soil. In recent years, research on strength and deformation characteristics of the expansive soil became a hot topic. The grea- test feature for the expansive soil was that its strength property affected by the seasonal climate changed obviously. By simulation of soil seasonal shrinkage wet expansion, the authors tested the liquid and plastic limits, free expansion, shear strength and unconfined com- pressive strength. By analysis of experimental data, other experimental data and the experimental data of doped with 7% lime improved soil, explored the impact of the drying and wetting cycle effects on expansive soil strength.