含水率对软土压缩特性影响试验研究

Experimental Study on the Effect of Moisture Content on Compression Characteristics of Soft Soil

土的压缩固结与土体的类别和性状、初始含水率、加载方式、排水条件等因素有关。结合松花江避暑城战备路工程实例,取同一路段软土重塑土样进行室内快速固结试验,测定其不同含水率条件下的s-p曲线、e-p曲线并计算压缩系数。试验结果表明:在前期固结压力作用下,含水率变化对土的压缩系数和沉降量有重要影响,在同一级荷载作用下,土的轴向变形随含水率的增加逐渐增大;土样含水率越大,孔隙比的变化速度越快,土样越容易被压缩;随着固结压力增大,土样孔隙比的变化率减小,压缩变化量也越来越小。其压缩系数的变化符合常规固结试验中的一般性压缩规律,快速固结试验法在一定程度上能正确反映土的压缩特性,满足指导施工的要求。

The compression consolidation of soil is related to the type and characters, the initial moisture content, loading mode, drainage condition and so on. Combined with the engineering project of Bishucheng Zhanbei road of Songhua River, the remolded soil sampled in the same road was used to carry out the indoor rapid consolidation test. The s -p curve, e - p curve were measured under different water contents and the compression coefficient av was calculated. Test results showed that the water content had important effect on compression coefficient and settlement of soft soil under the pre - consolidation pressure. Under the same load, the axial de-formation gradually increases with increasing water content of soil ; the greater the soil moisture content, the faster the speed of change in void ratio, the more easily compressed soil samples. With increasing consolidation pressure, the change in the void ratio of soil sample decreases and the amount of compression is getting smaller and smaller. The change in compression coefficient of the soil com-plies with the general compression law in the conventional consolidation test. The experimental method can reflect the compressibility of soil to a certain extent, and meet the requirements of construction.