一种新型测量非饱和土吸力的方法

A New Method for Measuring the Suction of Unsaturated Soil

本文主要通过冷镜露点水势仪、离心机法和滤纸法对非饱和粘土及其与砂的土壤混合物的吸力进行测试研究,提出了一种新测量非饱和土的吸力的方法,并把新型方法与本文涉及到的三个传统方法做对比,通过理论分析、数据梳理、总结归纳出创新渗透技术测量非饱和土吸力的正确性、可靠程度与局限性。主要的研究内容和成果如下:1) 在利用WP4C冷镜露点水势仪对不同配比高岭土、膨润土及砂(文中分别用K、B、S表示)的土壤混合物吸力测定中,实验表明在脱水路径和吸湿路径之间存在滞后现象。吸力的增强或减弱不全是与掺入土壤的颗粒大小有关,而是与掺入土颗粒的持水能力和性质有关。2) 通过离心技术得到的土壤混合物吸力与冷镜露点水势仪得到的结果比较吻合。3) 在滤纸实验中采用高岭土作为研究对象,滤纸法测定的吸力与WP4C偏差为10%~16%。4) 在创新渗透技术实验中,创新渗透技术需要3~5天测量吸力,这种新技术测定克服了大吸力测定的局限性。利用该技术与WP4C得到的数据对比,结果显示吻合较好。

In this paper, through the dew point potentiameter instrument, centrifuge method and filter paper method to measure the suction of unsaturated clay and sand soil mixture, a new method to measure the suction of unsaturated soil is proposed, and the new method is compared with the three traditional methods involved in this paper. Through theoretical analysis, data sorting and summary, the correctness, reliability and limitation of the innovative infiltration technology for measuring the suction of unsaturated soil are summarized. The main research contents and results are as follows: 1) The dew point water potentiameter was used to measure the suction of soil mixtures with different ratios of kaolin, bentonite and sand (They are expressed by K, B and S respectively) in the process of dehydration and moisture absorption. The experimental results show that there is a lag between the dehydration path and the moisture absorption path. The increase or decrease of suction is not entirely related to the size of soil particles, but to the water holding capacity and properties of soil particles. 2) The suction of soil mixture obtained by centrifugal technique is in good agreement with that obtained by cold mirror dew point water potential meter. 3) In the filter paper experiment, kaolin was used as the research object, and the deviation between the suction measured by filter paper method and wp4c was 10% ~ 16%. 4) In the experiment of innovative penetration technology, it takes 3 ~ 5 days to measure the suction, which overcomes the limitation of large suction measurement. Compared with wp4c data, the results show good agreement.