Experimental Study On Lateral Deformation And Creep Test Of Subgrade Compacted Loess Under Lateral Control

At present,subgrade settlement calculation methods mostly use the method of calculating the subsidence of the foundation.The soil parameters used in this method are mostly obtained based on the one-dimensional compression test,and little consideration is given to the influence of lateral deformation on the soil parameters.However,for the subgrade,its stress state and deformation are different from those of the foundation.Therefore,using this method to calculate the settlement of subgrade will produce a greater error.In addition,creep settlement is the main component of post-construction settlement of subgrade.However,there is insufficient research on the creep characteristics of compacted loess under submerged conditions,especially for less than 600 days of compaction of loess under submerged conditions.This is difficult for studying the long-term deformation characteristics of the subgrade under submerged conditions.Therefore,based on the reconstruction and expansion project from G307 Suo De to Wubao,the paper carried out a compaction test of compacted loess under lateral controlled conditions and a creep test under submerged conditions,focusing on the analysis of lateral constraints.The compressive deformation characteristics of compacted loess and the creep properties under flooding conditions are used to make up for the insufficiency of the subgrade settlement calculation method.A In this paper,according to the research content,a test device similar to three-way loading is designed.The device is calibrated and verified with rigid and elastic test pieces.The results show that the device has good reliability and meets the test requirements.Based on the three-way loading equipment,the compaction tests of compacted loess under different compaction degree,different constraining conditions and laterally reserved deformation conditions were carried out.The deformation characteristics and lateral forces of compacted loess under lateral constraints were analyzed.The relationship between vertical forces.With the assumption of the deformation characteristics of compacted loess under lateral restraint and the unchanged volume of soil particles before and after compression,the compression,void ratio,compression modulus,etc.under lateral deformation conditions and full lateral restraints are obtained.The relationship between the indicators,combined with the actual test values and calculated values of the indoor test were compared.Based on the characteristics of lateral deformation of soil samples,the deformation coefficient ξ is introduced,and the calculation formula of the deformation coefficient ξ in three-dimensional space and two-dimensional plane state is obtained based on Hooke’s law.Based on the above,the creep characteristics of compacted loess under submerged conditions were studied.The creep law of compacted loess under water-immersed condition was analyzed.The stress-strain-resistance of compacted loess under submerged conditions was obtained.The creep empirical formula of time,through the first and second derivation of the corresponding change and time,shows that the creep of compacted loess under immersed water is attenuated creep,and finally the subgrade creep settlement under local flooding conditions is performed.prediction.