Optimization Test Research On The Grouting Repair Technology Of Connection Damage For Ballastless Track

The connection damage of track slab and support layer is one of the main failure of the ballastless track structure,which sreiously affect the interlayer force transmission characteristics and service performance of track structure.Presently,the construction parameters of the connection damage grouting repair process of ballastless track is mainly set by experience,lacking effective theoretical guidance.In this paper,the rough interface and smooth interface of indoor scale model of connection damage was designed and fabricated according to the principle of flow similarity.By experiment,the diffusion characteristics of grouting inner connection damage was abtained,and the hypothesis of connection damage critical depth and the judge guidelines of connection damage grouting dense were proposed.Combined with Fluent fluid mechanics simulation software for comparative analysis,the optimization proposal of connection damage repair technology of ballastless track was obtained.The main contents and conclusions are as follows:(1)The indoor scale model of connection damage was poured,to ensure that the width of specimen's connection damage and the operating line's were the same.According to the principle of consistency of viscosity,the grouting was prepared using of giycerol for the experiment.(2)Under different line conditions,the grouting inner connection damage appromiately diffused at semicircle,and the diffusion radius spuare was linear with the grouting time,which were consistent with the calculation results of the fluid dynamics simulation software.The maximum spacing of grouting pipe was about 40cm.When the grouting pipe spacing were 20cm,30cm and 40cm,the diffusion radius of the grouting inner connection damage from the smooth interface specimen were 34cm,36cm and 40cm.the diffusion radius of the grouting inner connection damage from the rough interface specimen was about 5?8cm shorter than the diffusion radius of the grouting inner connection damage from the smooth interface specimen.In a certain range of viscosity,the diffusion radius of the grouting and other grouting indexes had little relationship with the viscosity of the grouting.The pressure trough value of the smaller viscosity grout was negative when grouting,which was disadvantageous to the effect of grouting repairing.Therefore,a slightly larger viscosity of the grouting could be chosen.(3)Based on the semicircular diffusion inference of the grouting inner connection damage,The relationship between the diffusion radius and the critical depth of the connection damage was proposed,so as the relationship between the grouting pipes embeding depth and conenction damage depth.The experimental results were in good agreement with the deduced hypothesis,and the optimization of the construction parameters of the connection damage grouting repair process was put forward.When drilling and layouting grouting pipes,the layout of combination with grouting pipes and exhaust pipes could be used.During the grouting process,the junped grouting method could be used.The rationality of connection damage critical depth under different conditions was proved according to the calculation results of the fluid dynamics simulation software.Simultaneously,it was consistent with the diffusion of the grouting when the grouting pipes were embeded in different depth.It was illustrated that the embeded depth of the grouting pipes based on the connection damage critical depth hypothesis could make the connection damage grout full and achieve the criterion of grouting full.