酸污染对黄土力学特性影响及机理研究OA

Geotechnical engineering problems caused by environmental issues have greatly threatened human production and life.To investi-gate the influence and mechanism of acid contamination on the mechanical properties of loess,loess from the Guanzhong area was taken as the research object,and HCl solutions with four concentrations(4%、8%、12%and 16%)were selected as the contaminant.A GDS triaxial ap-paratus was used to study the effect of HCl on the strength characteristics of the soil.On this basis,XRD and SEM tests were adopted to ana-lyze the internal mechanism of the strength variation of loess under HCl action from the perspectives of mineral composition,soil microstruc-ture and pore changes.The results show that HCl solution degrades the maximum deviator stress,cohesion and internal friction angle of the soil to a certain extent.The influence of HCl solution on the mechanical properties of the soil is mainly caused by the change of soil micro-structure:after HCl treatment,the number of soil pores increases,the flocculent structure in the soil disappears,and the flaky particles in-side large aggregates are exposed,resulting in the reduction of deviator stress strength and cohesion.The increase of soil pores and the smal-ler resistance required for rolling and sliding between particles lead to the decrease of internal friction angle.