Analysis Of Coupling Dynamic Characteristics Of High-speed Railway Foundation-roller

The high-speed railway subgrade is the foundation of the track structure.In order to provide a safe and stable operating environment for high-speed trains,the subgrade must meet the requirements of strength,rigidity,stability and durability.However,traditional research currently lacks scientific and reasonable detection methods for the dynamic response of subgrade fillers in the process of vibratory compaction.By establishing a finite element model of vibratory compaction to simulate actual engineering operations,it can directly reflect the actual compaction process of vibratory rollers to a certain extent.When the vibrating wheel compacts the soil,the internal dynamic response change process of the soil can dynamically reflect the action of the vibrating wheel on the soil during the compaction process.In view of this,this paper takes the dynamic response of the roadbed filler during the vibration compaction process of the roller as the research object,adopts the research method of the combination of theoretical analysis,field test and numerical simulation,and relies on the actual engineering of a high-speed railway foundation compaction to analyze the vibration compaction process.The dynamic response characteristics and evolution laws of subgrade filling materials have been explored to explore the influence of different parameter levels on the dynamic response of the soil.The orthogonal test analysis method is used to analyze the sensitivity of the influencing factors of vibration compaction.The main research work is as follows.(1)Based on the theory of vibration compaction dynamics and fully considering the coupling effect model of the vibrating wheel-soil system,a three-dimensional finite element numerical calculation model of the "machine-soil coupling" effect in the vibration compaction process was established,and the acceleration of the vibrating wheel was studied.The reliability and rationality of the numerical model are verified by the time history curve and the soil acceleration time history curve,combined with the field measured data.(2)Based on the established "machine-soil coupling" numerical analysis model of the vibration compaction process,the vibration compaction process and the static pressure process,the distribution state of the dynamic response of the subgrade filling under the roller of the roller,are analyzed,and the dynamic response of the vibrating wheel is obtained.The time-history curve of the vertical compressive stress and vertical acceleration of the subgrade filling is analyzed.The dynamic response of the subgrade filling during the vibration compaction process is explored along the depth direction and the horizontal direction.Based on this,the dynamic response of the vibration compaction is proposed.Range and dynamic response boundary along the depth direction.(3)Based on the field test and the finite element numerical model,the model vibratory roller is used for the field test,considering its mechanical properties(exciting force frequency,exciting force amplitude,driving speed)and changes in soil elastic modulus to affect the depth And the impact of compaction effect,the parameter analysis is carried out to provide a certain theoretical reference and basis for the concrete roadbed compaction project,and the sensitivity analysis of the influencing factors of vibration compaction is carried out using the orthogonal test analysis method.This paper clarifies the effective technical approach of the finite element numerical calculation method for dynamic response analysis of subgrade filling in the vibration compaction process,and based on the sensitivity analysis results under different working conditions and different parameters,it is committed to increasing the subgrade filling pressure in the process of vibration compaction.The actual quality is used for better service engineering practice.