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为了探索软夹杂土体压实机理,指导轻量土配方设计与压实施工,基于混合土物质结构组成及土体压缩变密的物理本质,建立了击实密度模型。试验发现模型预测值与实测湿密度基本一致,绝对误差仅有0.003~0.051 g/cm3,相对误差仅有0.282%~5.267%,证明击实密度模型可以准确预测混合土不同击实条件下的湿密度。EPS颗粒压缩率、混合土湿密度随击实次数增大而增大,增大趋势逐渐变缓;混合土孔隙比随击实次数增大而减小。在击实作用下,轻量土湿密度的提高是由土体的孔隙减少和EPS颗粒软夹杂的塑性压缩共同完成的。与砂土轻量土性质相似,粘土轻量土的湿密度、无侧限抗压强度随击实次数增大而增大。n=25击时,EPS颗粒压缩率范围6.13%~11.51%;n=94击时,EPS颗粒压缩率范围12.80%~14.87%。证明规范规定的击实次数与击实能量适合混合土的击实,不会导致EPS颗粒消泡。考虑到击实密度模型参数测定非常繁琐,根据工程实际情况,假设压实过程中土料含水量不变与压实后土颗粒-EPS颗粒之间的孔隙近似为0,进一步提出了简化击实密度模型,并且通过试验证明了简化模型完全适用于实际工程。
In order to explore the compaction mechanism of soft soil and guide the design and compaction of lightweight soil, a compaction density model was established based on the physical structure of the mixed soil and the physical nature of soil compaction and densification. The experimental results show that the model predictions are consistent with the measured wet densities. The absolute error is only 0.003 ~ 0.051 g / cm3, and the relative error is only 0.282% ~ 5.267%. It can be concluded that the compaction density model can accurately predict the wettability of mixed soil under different compaction conditions density. The compression rate of EPS particles and the wet density of mixed soil increase with the increase of the number of compaction times, but the increasing trend gradually becomes slower. The porosity ratio of mixed soil decreases with the increase of compaction times. Under the action of compaction, the increase of wet weight of lightweight soil is accomplished by the reduction of soil porosity and the plastic compression of soft inclusions of EPS particles. Similar to the lightweight soil of sand, the wet density and unconfined compressive strength of lightweight clay soil increase with the number of compaction times. At n = 25 hitting, the compression rate of EPS particles ranged from 6.13% to 11.51%. At n = 94 hitting, the compression rate of EPS particles ranged from 12.80% to 14.87%. Proof of the number of compulsory provisions of the compaction and compaction energy for compaction of soil compaction, will not lead to EPS particle defoaming. Considering that the determination of compaction density model parameters is very complicated, according to the actual situation of the project, assuming that the soil moisture content during compaction is unchanged and the pore size between compacted soil particles and EPS particles is approximately 0, further simplified compaction Density model, and the experiment proves that the simplified model is completely suitable for practical engineering.