Study On The Mechanical Properties And Microstructure Of Zinc Contaminated Guilin Remolded Red Clay

Red clay is a kind of regional special soil formed by carbonate rocks which affected by special regional geological environment.In Guilin,the development of red clay is typically.The shear strength of red clay plays an important role in foundation stability.Because the engineering properties of red clay are rather special,the karst area is relatively developed in the main distribution areas and often induces many engineering geological problems,such as instability of the roadbed and uneven settlement of the foundation.In the karst area,there are many non-ferrous metals mining.In the process of mining,it will inevitably pollute the surrounding red clay.Therefore,the mechanical properties of red clay contaminated by heavy metals will undergo some changes.The study of the mechanical properties of soils contaminated by heavy metals has become the focus of scholars’ attention.This article focuses on the indoor artificial pollution Guilin reconstituted red clay,its triaxial test,X-ray diffraction mineral analysis test,X-ray fluorescence analysis test,mercury injection test,electron microscopy scan test,the remodeling red clay mechanics after zinc ion pollution The nature,mineral composition and microstructure change rules were studied and analyzed.The main research contents of this article are as follows:(1)Through the triaxial unconsolidated undrained shear test,the variation of mechanical properties of remolded red clay with different zinc ion concentrations,different dry densities and different confining pressures was analyzed.The experimental results show that the increase of zinc ion concentration will reduce the shear strength of remolded red clay,and the cohesion and internal friction angle will also decrease.Increasing the dry density will increase the shear strength of remolded red clay.The increase of confining pressure will increase the shear strength of reconstituted red clay,and the stress-strain curve of soil samples will be hardened.(2)Through the analysis of mineral composition of soil samples before the zinc ion contamination and the after,the influence of mineral changes on the mechanical properties of remolded red clay was studied.The results showed that as the mineral components of soil samples pollution changed,the content of iron oxide decreased.More obvious.(3)Through the mercury intrusion test and electron microscope scan test,the changes of the microstructure of the soil samples before and after the pollution were analyzed,and the macroscopic mechanical changes were studied through the microstructure changes.The experimental results show that the pore complexity of the soil sample contaminated by zinc ions is significantly increased,and the porosity is proportional to the zinc ion concentration.The large pore volume of the sample does not change significantly,and the volume of small pores increases significantly.