Experimental Study Of Lime And Flyash Treated Collapsing Soil In Gannan Region

In this experiment,the collapsing soil in Yudu County,Gannan District,Ganzhou City,Jiangxi Province is taken as the experimental research object.The consolidation test and unconfined compressive strength test are used to analyze the influence of single factor fly ash,double factor fly ash and lime as additives on the mechanical properties of collapsing soil under the same dry density and the same moisture content.The triaxial consolidation and drainage shear tests were carried out on the collapsing soil samples with improved materials.The change trend of the internal friction angle and cohesion of the soil samples under the conditions of single factor fly ash and double factor fly ash and lime were determined according to the test data.According to the data analysis,the improvement effect of double factor addition is better than that of single factor addition,and the optimal proportion is 5% fly ash and 5% lime.Through consolidation test,the stress-strain curve,time-pore water pressure curve,axial strain volume strain curve and axial strain confining pressure volume strain curve of soil mass in different fly ash and the amount of fly ash and lime are obtained.Through the study and analysis of the curve,it is found that the curve has significant changes,and its stress-strain curve conforms to hyperbolic model.The unconfined compressive strength of soil was tested,and the improvement effect of adding different proportion of fly ash,fly ash and lime as additives under the same dry density and moisture content of soil was analyzed.In the test results,the improvement of compressive strength of flyash soil is small and still presents brittle failure,but the strain decreases when failure;the compressive strength of flyash soil increases significantly,and presents ductile failure when failure.The results show that with the increase of lime content,the effect of lime on the improvement of the compressive strength of rockfall soil increases first and then weakens,and the optimal proportion of the effect of lime on the improvement of the compressive strength of rockfall soil is 5% fly ash and 5% lime,and the effect of lime on the improvement of the compressive strength of soil is better than that of fly ash.Based on the above experimental data,GeoStudio software is used to simulate and establish the model of landslides in Gannan area,and analyze the stability of landslides under different conditions of adding materials.The results show that the effect of fly ash as a single factor on slope stability improvement is weak,but the effect of fly ash and lime on slope stability improvement is significant.When the slope stability coefficient reaches the peak value,the proportion of fly ash 5% and lime 5%.