Stability Analysis Of Spoil Ground Considering Creep Effect

In recent years,with the vigorous development of China's infrastructure,a large number of spoil ground projects are increasing.Therefore,in order to ensure the safety of the engineering site operation and eliminate hidden safety hazards,the importance of the calculation and evaluation of the stability of the spoil ground is increasingly highlighted.Generally,the analysis of the stability of the spoil field is to treat the soil as an elastoplastic body for stability analysis and evaluation,ignoring the creep characteristics of the rock and soil body,that is,its deformation continues to increase with the development of time under long-term load It even led to the instability of the spoil ground and caused the project to fail.Therefore,the creep effect needs to be taken into account when designing and subsequent treatment of the spoil ground project.The creep effect is closely related to the composition,nature and stress history of the soil.The soil environment in different regions is different,and the creep law is also very different.Choosing the appropriate constitutive model can truly and accurately reflect the soil creep process The changing laws of stress,strain and time can make a better prediction of the actual project.This article takes the spoil field project of the Guangji Line as an example,and uses a combination of creep theory and indoor direct shear creep test to study its creep law.By using the numerical analysis software to process and fit the data obtained from the direct shear creep test,a creep model that can accurately describe its creep law was found.With the help of FLAC3D numerical simulation software,the stability analysis of the Guangji line spoil yard project was carried out,and the influence of creep effect on its safety factor was studied.When the creep effect is not considered,the stability analysis of the slope of the spoil yard in the elastoplastic state is carried out,and the safety factor of the slope of the spoil yard of the Guangji Line is 1.36.The maximum displacement in the X direction is 3.1cm,and its position is at the foot of the slope of the spoil field;considering the effect of creep,after 2 years,3 years,and 5 years of creep development,the X direction of the slope of the spoil field The maximum displacements occurred were 4.21 cm,5.30 cm,and 6.82 cm,respectively.After 7 years of creep,the spoil ground is basically stable,and the maximum displacement in the X direction is about 6.96 cm.Compared with the maximum displacement in the X direction of 3.1 cm in the elastoplastic state,the maximum displacement increased by 124.52%.Moreover,the position of the maximum displacement in the X direction of the slope of the spoil ground under different creep times is all at the foot of the slope.Because the shear stress is concentrated at the foot of the slope,it is most likely to break.When the creep effect is not considered,the safety stability factor of the spoil yard slope under the elastoplastic state is 1.36,and the safety stability factor of the spoil yard under the creep effect is 1.04,and the safety factor without considering creep This is a decrease of 23.5% compared to 1.36.Among them,1.36 can be used as the short-term stability index of the spoil yard.It is recommended to adopt 1.04 as the safety stability factor of the spoil yard in the design of the actual spoil yard and the subsequent engineering treatment design.Except for the spoil yard on the Guangji Line,when conducting stability analysis on other spoil yards and actual slope projects,we have to take creep factors into consideration in order to improve the safety and economy of the project.