| Located in the Huangfan District of Yudong,Kaifeng is located in the middle and lower reaches of the Yellow River.It is rich in silt reserves and is closed to Zhengzhou.It is an important city in the Central Plains.With the accelerated development of Zheng kai integration,the rapid development of engineering construction in Kaifeng has been promoted.The soil of silty sand is the product obtained by weathering the rock.The particles are uniform,the lithology is loose,the permeability is good,the clay content is relatively small,and it is easy to be destroyed under the load of earthquake and traffic.It has great scientific significance and practical value to research the dynamic characteristics of silty sand in Kaifeng area.In this paper,the dynamic characteristics of unsaturated silt soil in Kaifeng area under small strain conditions(10-5-10-3)are studied by GDS resonance column system,and some conclusions were obtained.?1?By reviewing the relevant literatures,the research status of the dynamic characteristics of silty sand under small load was summarized.The soil samples taken were subjected to screening test and compaction test to determine the type of soil,With silty sand.the optimum moisture content and maximum dry density of silty sand were obtained.?2?Through a large number of resonance column tests,the effects of confining pressure,fine particle content and dry density on dynamic shear modulus and damping ratio of silty sand were studied.The curves of dynamic shear modulus and damping ratio and dynamic shear strain under different influencing factors were obtained.The influence mechanism of different influencing factors on dynamic shear modulus and damping ratio was analyzed.The test results show that with small strain,with the increase of confining pressure and dry density,the dynamic shear modulus of the sample increases gradually,and the damping ratio decreases.With the increase of fine particle content,dynamic shearing The modulus of cut does not exhibit a linear change,but decreases first and then increases.When the fine particle content is 25%,the dynamic shear modulus reached a minimum value,and the damping ratio first increases and then decreases.When the particle content is 25%,the damping ratio is the largest.?3?The experimental data were processed and analyzed,and the curves of dynamic shear modulus ratio and dynamic shear strain under different dry density,confining pressure and fine particle content were obtained.?4?The Hardin-Drnevich constitutive model was used to fit the 1/G–?curve and G/G0-?curve of the silty soil in Kaifeng area;the?-?curve and G/G0 of the silty soil in Kaifeng area were calculated by Davidenkov constitutive model.Comparative analysis of the fitting results.The fitting parameters suitable for the soil studied in this paper were obtained. |
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