确定渗析法和滤纸法平衡时间的试验研究

Experimental study on equilibrium time of osmotic technique and filter paper method

吸力是非饱和土的重要参数,渗析法和滤纸法是2种测量土体吸力的重要方法,但是渗析法和滤纸法达到平衡的时间主要依靠经验,缺少系统的试验研究。文章以合肥市非饱和黏土和粉质黏土为研究对象,研究在不同溶液吸力下渗析法达到平衡的时间,以及在不同土样初始含水率条件下滤纸法达到平衡的时间。结果表明,溶液吸力较小时,渗析法的平衡时间约为2d;滤纸法的平衡时间约为2d,对于接触型滤纸,土样初始含水率越大,则滤纸法平衡时间越短,而对于非接触型滤纸,土样初始含水率对平衡时间的影响较小。

Suction is one of important parameters in unsaturated soil. Osmotic technique and filter paper method are important for measurements of soil suction, but the time of osmotic technique and filter paper method to reach equilibrium relies mainly on experience, there are few systematic theoretical results in this respect. In this paper, taking unsaturated clay and silty clay in Hefei City as the research object, the equilibrium time of osmotic technique in different solution suction and the equilibrium time of filter paper method under different initial soil moisture content is researched. The results show that the equilibrium time of osmotic technique is about 2 d when the solution suction is small, and the equilibrium time of filter paper method is about 2 d. For the contact filter, the equilibrium time decreases with the increase of initial soil moisture content. For the non-contact filter, the initial moisture content of the soil sample has little effect on the equilibrium time.