Research On The Engineering Properties Of Jingyang Q₂ Loess Based On True Triaxial Test

Loess,a special kind of soil widely distributed in our country,is often used as project carrier.Currently a lot of large-scale projects are built in this area.Causing loess disasters and loess problems are increasingly prominent,and making the study of loess engineering properties is very important in geologic engineering.At present,the Q₂ loess is a type of soil that involves more engineering but relatively few studies.In order to study the engineering properties of the Q₂ loess,this paper selects the Q₂ loess in South Jiangyang Plateau,and true triaxial tests were conducted on this loess.Based on true triaxial test results,the following studies were conducted in this paper:?1?A series of true trixial tests were carried out to study the effects of the water content w,consolidation pressure?₃,and Bishop's parameter b on the engineering properties behaviors of the Jingyang Q₂ loess,which include the properties of stress-strain,volumetric strain,structure,and strength.?2?Proposed two structural parameter expressions which are the state stress ratio structural parameter m_z and relative state stress ratio structural parameter D_m,and studied the law of change about the two structural parameters under different working conditions.?3?Based on the experimental results,two methods for the division of loess structure were proposed,besides explored the internal relations between the two structural parameters.?4?A relations have been analyzed that it includes state stress ratio structural parameter m_z and its strength,based on this relationship a new mathematical expression that it can consider both of strength and structure property have been proposed.?5?Based on the true triaxial tests data of Jingyang Q₂ loess,the law of applicability about the strength of Jingyang Q₂ loess considered in each classical strength criterion was analyzed.The study results show that:the three criteria reflect the strength of Jingyang Q₂ loess to different extents.The fitting effect of TSUST criterion is the best,while the fitting effects of the other two failures criteria are changed with the water content.And it's also recommended that the best value of the TSUST criterion's parameter b is 0.2 to 0.4 when this criterion predicts the strength of Jingyang Q₂ loess.