基于干湿循环作用的红黏土强度特征分析

Analysis of Strength Characteristics of Red Clay Based on Wetting and Drying Cycle

红黏土是一种典型的特殊土。以经历了干湿循环作用的红黏土为研究对象,通过直剪试验,探讨了干湿循环对土体强度的影响。研究表明,往复的干湿作用使红黏土强度特征发生变化,主要体现在:在低竖向荷载作用下,红黏土随着干湿循环次数增加,强度呈减小趋势;但在较高的竖向荷载作用下,红黏土强度随干湿循环作用次数的变化趋势不明显;随着干湿循环作用次数的增加,红黏土黏聚力不断减小,并趋于一较小的稳定值;内摩擦角反而随着干湿循环次数的增加而有所提高,同时也趋于一稳定值。

Red clay is a typical special soil. Red clay has been studied by direct shear test after undergo- ing a wetting and drying cycle to analyze the influence of wetting and drying cycle on soil strength. The results show that the cycle changes the strength characteristics ： Under low vertical load, soil strength decrea-ses with the wetting and drying cycle increases. Under higher vertical load,soil strength shows no considera-ble change with the cycle going on. With the increase of wetting and drying cycle, cohesion of red clay de- creases and tends to stabilize at a small value. The internal friction angle increases with the increase of wet- ting and drying cycle and stabilizes at a value.