| With the increase of people’s travel demand,the demand for high-speed railway is increasing day by day.The rapid development of high-speed railway lines not only provides convenience to more people,but also brings many problems.The vibration caused by rail fatigue and wear caused by high-speed trains running for a long time spreads to the earth through the subgrade and has adverse effects on buildings and residents along the railway.The harm caused by vibration has attracted extensive attention of experts and scholars at home and abroad.Under this background,scholars at home and abroad put forward the method of applying vibration reduction and isolation measures to reduce the impact of vibration.Combined with the existing research content,this thesis proposes to apply horizontal pile row in the subgrade as vibration reduction and isolation measure,and analyzes the influence law of different parameters of horizontal pile row on soil vibration.Through the model test and finite element model test,the amplitude of soil surface is analyzed and studied.In the finite element model test,the amplitude of soil mass on the ground surface,1/3 octaf and maximum Z vibration level are analyzed,and the influence law of horizontal pile row on the vibration caused by high-speed train running is analyzed from multiple angles.Under the research conditions of this thesis,the following conclusions are obtained:(1)In the model test,the influence of vibration source frequency,pile depth,pile filling rate,pile diameter and other factors on soil amplitude was analyzed by comparison of control variables.The results show that the pile row has a poor inhibition effect on the soil vibration caused by high frequency waves,but a more obvious inhibition effect on the soil vibration caused by low frequency waves.The smaller the depth of pile row is,the more obvious the inhibition effect on soil vibration is.The more the depth of pile row is,the less the inhibition effect on soil vibration is.The larger the filling rate of pile row layout area,the more obvious the inhibition effect on soil vibration.The larger the pile diameter,the more obvious the inhibition effect on soil vibration.(2)Combining with the spectrum specifications of ballastless track unsmoothness of high-speed railway in our country and existing research results,calculate the track unsmoothness displacement curve,apply it to the model to realize the simulation of train driving unsmoothness.By establishing a finite element model of equal proportions with the model test,the data results of the same measuring points were compared and analyzed to verify the effectiveness of the model and provide support for the subsequent finite element model calculation.(3)A large-size analysis model is established to simulate the vibration of high-speed railway trains during running,and the influence law of the vibration of trains is studied by applying horizontal pile row.In the finite element model,the three factors affecting the buried depth,pile diameter and filling rate of single row pile,whether the double row pile is cross-placed or not,and the distance between the pile rows are analyzed.The results show that with the increase of the buried depth and pile diameter of single row pile,the soil vibration on the surface near the railway can be suppressed,and the 1/3 octave and maximum Z vibration level can be attenuated to a certain extent.With the increase of the filling rate of single row pile,the soil vibration on the surface of subgrade can be significantly inhibited,and the 1/3 octave and maximum Z vibration level can also be significantly attenuated.The double-row piles in the roadbed can inhibit the vibration to a certain extent,and the effect of cross-row piles is better than that of non-cross-row piles,but the overall effect is almost equal to that of single row piles. |
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