Study On Dynamic And Static Characteristics And Settlement Factors Of Subgrade Soil In Zhangjiakou Area

The State Council plans to build national highway network which scale of about400 thousand kilometer from 2013 to 2030,compared with the railway only shuttle in the big city,highway for links in different regions and people's travel and life becomes more and more important,the highway's safety and comfort are also getting more and more attention.Due to the effect of long-term traffic loads and the change of conditions outside subgrade surface is very easy to form uneven settlement,it has brought a great threat to the safety of people and vehicles driving at the same time,while the settlement will increase the vehicle and roadbed dynamic role,thus causing more serious damage.People in the past research mainly focused on determining the settlement of subgrade settlement calculation model,but due to the limitation of test method and the model has great limitations,and cann't on the actual construction and operation of the project put forward constructive suggestions.The successful application of the 2022 Winter Olympics and the acceleration of the integration of Beijing,Tianjin and Hebei,Making the highway construction of Zhangjiakou area has entered a new stage of development.In this paper,Zhang Xuan road to the village section of the alluvial fans in the silty clay as the research object,firstly study the basic physical indexes of soil,provide the basis for the subsequent static and dynamic three triaxial test;through indoor static three triaxial test for the relationship between the soil shear strength index and elastic modulus with soil compactness and other physical indexes,and explore the change trend of slope safety factor with compaction degree is analyzed by finite element software.analyze the change of soil dynamic elastic modulus under the long-term cyclic loading with the dynamic tests,explore the effects of soil physical properties such as compaction degree and experimental conditions such as confining pressure and frequency on cumulative deformation of soil mass,the influence of different factors on subgrade settlement is studied from the experimental point of view and sensitivity analysis is introduced to quantify the influence of different factors.Finally established the subgrade model by finite element software,introduce the selection of parameters and the basis of power application,analysis the change trend of subgrade settlement under different conditions by finite element software,study the effect of different conditions on subgrade settlement by sensitivity analysis method,based on the results of dynamic test and finite element analysis,puts forward some measures to reduce subgrade settlement.