Application Of Churning Pile In Strengthening Heavy Haul Railway Subgrade

At present,the development of heavy haul railway in China mainly uses expanding and rebuilding capability of the existing mode.At the beginning of design,the subgrade strength standard of the existing mode was low and the subgrade strength of part section was difficult to satisfy the heavy haul railway.So,in order to adapt to the China’s increasing development of heavy haul railway freight demand and the axle load,it urgent needs an effective method of heavy haul railway subgrade reinforcement to solve the problem of insufficient bearing capacity of foundation,without affecting the normal operation of railway heavy haul railway.In this paper,intensive studied several common subgrade diseases and analyzed formation mechanism.Then carded several common methods of subgrade reinforcement.The main content includes design method,construction preparation,construction process,construction quality control methods and post construction monitoring.The test section was in the Shuohuang Railway Roadbed section K65+490~K65+770.Used the construction technology of high pressure jet grouting pile on the existing railway subgrade reinforcement technology application.The results of the study show that:(1)There is no process of strengthening construction technology of high pressure jet grouting pile in the subgrade in heavy haul railway affects the normal operation of heavy haul railway.Compared with the commonly foundation reinforcement method,high pressure jet grouting pile construction technology application in heavy haul railway roadbed is better in cost reduction,high intensity,construction speed,high reliability;(2)The construction technology of high pressure jet grouting pile can substantially increases the shear strength of Subgrade in heavy haul railway greatly.It stopes the roadbed continues to sink,construction expediently,the upper stability is good.And construction equipment is compact compac,small volume,strong maneuverability,less land occupation,construction machinery and vibration is small,the low noise.It has no effects on the surrounding buildings in vibration and noise.(3)The application results show that the compactness of the subgrade and the soil in the base treatment area has been improved obviously after the reinforcement.The maximum settlement of the subgrade is 7 mm or so,and the settlement after the construction conforms to the state regulations.