Experimental study on physics and mechanics performances of coal refuse backfill soil

In order to find the relationship between the sand content of coal refuse backfill soil and the strength,a mixing ratio with the engineering application was det ermined. An experimental study was conducted on the physical performances( moisture content,max dry density,optimum moisture content) and the mechanics performanc es( particle size distribution,compression coefficient,cohesion and internal friction angle) of the coal refuse backill soil under the different mixing ratio condition. Based on a linear regression prediction model established with the experiment data,a prediction was conducted on the foundation loading features and parameters. The experiment 「 esults showed that nonuniform cofficient of the coal refuse backill soil was 6. 44,the curvature cofficient was 1. 621 and the graduation was good and was favorable to t he compaction. The compression coefficient of three mixing ratio experiments was 0. 31,0. 29 and 0. 26 individually and was a high compressive soil. After the loess mixing value of the experiment soil sample continuously increased,the shear stress,cohesion and internal friction angle also would be increased and the shear strength of the soil. sample would be increased with the loess mixing ratio increased. According to the index prediction value ,the foundation loading feature value was calculated and obtained to meet the requirements of the constructional standards.