Abstract: Under the hydraulic action, the saturated sand intrusion might occur and then induce the ground subsidence to form a funnel-shaped depression zone. This paper proposes a prediction model of sandy soil subsidence range, and the expressions of the settlement radius and depth at the center of the subsidence are presented. This formula can directly predict the range and volume of subsidence. The potential influencing factors involved in the expression are evaluated through the model tests from the fine grain content, hydraulic gradient, and diameter of the sand intrusion zone. The results show that the subsidence zone formed after the intrusion is approximately funnel-shaped, and the average of the relative errors between predicted values and measured values of subsidence radius and depression center depth are 5.6% and 7.4%, respectively. The proposed model can predict settlement range accurately. According to the predictive model, the influence of the soil fine grain content, hydraulic gradient, and the diameter of the sand intrusion zone on the ground subsidence induced by sand is consistent with the laboratory test results. 

Key words: sandy soils, settlement range prediction, fine grain content, hydraulic gradient, diameter of intrusion