Research On Strengthening Effect Of Oblique Jet Grouting Pile Used In Bridge-subgrade Transition Section In Heavy Haul Railway

Heavy haul railway is an effective way to enhance the efficiency of railway transportation, and it has significant effect in solving problems existing in long-distance, bulk cargo transports. But the axle load, high-density traffic put forward higher requirements on railway alignment. Since the engineering properties of subgrade and bridges are quite different, serious unevenness is prone to occur in the linking of subgrade and bridges, which has great effects on the safety and economical of heavy haul railway. So it's necessary to the transition of subgrade and bridges to be strengthened reasonably.The growing demand for transport capacity and the rapid development of heavy technology in our country speed up the pace of the expansion reconstruction of the existing railways. How to strengthen the bridge-subgrade transition without affecting the normal operation become the key factor in heavy haul expansion reconstruction of existing railways. Compared to the existing transition strengthen measures, oblique jet piles not only has the advantage of having no interruption on railway operation in the process of construction, but also has a certain role on preventing embankment diseases, and it is a comprehensive treatment on the transition section strengthen.Combined with the Shuo Huang Railway expansion conversion research topics, the effect of applying diagonal high Pressure jet grouting technology on subgrade in the transition of subgrade and bridges is researched. Based on the measured data of the Shuo Huang Railway test section, finite element analysis model is established by finite element analysis software ABAQUS. Based on the comprehensive consideration of wheel-rail contact, pile-soil contact, group effect and the boundary conditions and other factors, the transition subgrade settlement, static deformation and dynamic behavior are calculated, the relationships between the layout parameters including the point of jet pile, density, enhance layout parameters and the effect of strengthen are summed up.1. When the horizontal angle is 5-15°effective, the oblique rotating pile is more effective, and can further inhibit the transition section deformation of 10% to 20%;2.1.5m-2m pile density is appropriate, the deformation suppression of upgrading will be very limited when continue to increase pile density, but as the increase of the distance after abutment, it is conducive to reflex a ladder and two step deformation by adjusting the pile density.3. The strengthen in range 20m-25m is better and the ladder stability characteristics of subgrade settlement after abutment is apparently stable.The results show that:the application of Oblique rotating pile on subgrade strengthen in transition section will not only enhance the ability of Inhibition of settlement deformation and Improve the dynamic action of the train but also release roadbed disease to enhance its overall performance, and is a comprehensive treatment to the transition section. Reference is proposed to the capacity expansion of existing railway with no interrupt to the operation of lines.