Multi-Parameter Experimental Research on the Expansion Force Affecting Lime-Sand Piles under Preloading Pressure

Aiming at the problems that it is difficult to control the expansion force of lime-sand pile in the foundation correcting and how the upper existing structural pressure affects the expansion force of lime-sand pile, this paper adopts a new type of lime-sand pile reaction tester to carry out the experimental research on the expansion force of lime-sand pile under the influences of different pre-pressure, different mixing ratios, different heights, and different granular sizes. The purpose of this paper is to explore the influence of the pre-pressure brought by the existing building structure on the expansion force of the lime-sand pile and the coupling effect of the pre-pressure and other influencing factors on the expansion force of the lime-sand pile through the multi-parameter test. The results show that with the increase in pre-pressure, the expansion force of the lime-sand pile shows the trend of increasing first and then decreasing when the pre-pressure is 0.88 KN, the effect is most obvious and its expansion force can be increased by 14.9%. Within a certain range, the larger the proportion of quicklime is, the lower the expansion reaction force is. The expansion force of the lime-sand pile with the ratio of lime/sand/soil of 5:4:1 is the most ideal, and its value reaches 10.2 KN, which is 10% and 15.3% higher than the rest of the two groups, respectively. Within a certain range, the effect of specimen height change on the expansion force of the lime-sand pile is almost negligible. The smaller particle size of quicklime makes its reaction speed faster, the reaction degree is more full, and the expansion force is greater. The expansion force of the small particle size group was 12.1% and 34.2% higher than that of the medium and large particle size groups, respectively.