非饱和土砂土湿吸力

Study on absorbed suction of unsaturated sandy soil

为了研究非饱和砂土湿吸力的影响因素及变化规律,利用非饱和砂土作为挡土墙的填土,通过观测填土的临界深度,应用朗肯主动土压力理论求其似粘聚力,根据似粘聚力来研究非饱和砂土颗粒间湿吸力的变化规律。研究结果表明:非饱和砂土的湿吸力是随着含水量的增大而增大,且开始阶段速率变化大;当非饱和砂土具有湿吸力时,存在一个临界含水量和临界粒径;在含水量相同条件下,相同粒径磨圆愈好湿吸力愈大。该研究方法操作简单、新颖,其结论可为非饱和土的研究提供参考。

The influence factor and variation characteristics of absorbed suction for unsaturated sandy soil were investigated in this study. The unsaturated sandy soil was used to fill retaining wall. Through measuring the critical depth of the fill, the pseudo-cohesion can be calculated using the theory of Rankine active earth pressure. The variation characteristics of the absorbed suction in inter granular in unsaturated sandy soil were studied based on pseudo-cohesion. The study concludes as follows： the absorbed suction of unsaturated sandy soil increases along with the increment of moisture content, and the increase ratio is vary sharp at start; there is a critical moisture content and a critical particle size when the unsaturated sandy soil has the absorbed suction; and under the condition of same moisture content, and same particle size, the better rounded particle, the bigger absorbed suction. This study method is innovative and simple. The study conclusion can be used as a reference for the further study on unsaturated sandy soil.