Research On Construction Technology Of CFG Pile In Shanghai-kunming High-speed Railway

China has a vast territory and a large population.railway,as the artery of economic communication between the whole country,links the economic development of the east and west regions,and is also the link of the developed areas to promote the development of backward areas.With the rapid development of the national economy,the relationship between the regions is more closely,the uneven economic development in various regions,leading to a large increase in the capacity of railway transport.In order to adapt to the development of the times,our country began to speed up the railway from April 1997 to April 2007.during the ten years,six national railway speed-raising(in 1997,1998,2000,2001,2004 and 2007),from the initial national railway average speed of 48.1 km / h,to 70.18 km / h,the highest speed up to 350 km / h,when China enters the era of high-speed railway development.The development of high-speed railway has reduced the distance between different regions of our country,promoted the emergence of the city effect,promoted the close contact between the regions of politics,economy,culture and so on,and helped to promote the coordinated development between different regions and between urban and rural areas.In order to ensure the high speed railway in operation to achieve high capacity,strong transmission capacity,fast speed,good safety,high punctuality rate,comfort and convenience,low energy consumption,the high speed railway subgrade settlement of a high demand.In order to ensure the advantages of the high-speed railway in the operation of the full play and reflect,the design of high-speed railway for the settlement of the roadbed proposed " zero settlement" high standards and high requirements,so in the high-speed railway subgrade construction process,the control of the roadbed settlement is given the attention of the engineering and technical personnel.There are many geological conditions such as collapsible loess in Jiangxi area,such as collapsible loess,northeast and plateau areas have frozen soil and other malignant geological conditions,for different geological conditions,the high speed railway subgrade treatment put forward more requirements.Based on the concept of soft soil foundation and related papers and works on the research of soft soil foundation at home and abroad,this paper investigates the application scope and advantages and disadvantages of various measures on soft soil foundation,introduces the related damage characteristics of soft soil foundation,and summarizes the reinforcement measures for the soft soil foundation commonly used in the high-speed railway construction.According to the specific treatment measures,construction process,quality control experience and the data of later monitoring of subgrade in Jiangxi province,this paper discusses the applicability of CFG long spiral drilling core pipe mixture filling method to soft soil foundation treatment.The main tasks to be accomplished are as follows:(1)the applicable scope and advantages and disadvantages of the soft soil foundation treatment measures commonly used in the construction of high speed railway are summarized.(2)through the whole process participation in the construction process of a certain section of Shanghai-Kunming high-speed railway,the construction technical parameters and quality control experience of CFG pile in the construction of Shanghai-Kunming high-speed railway are summarized.(3)through the data collection and analysis of the test data of the CFG pile foundation and the settlement observation data of the subgrade in the late section of the Shanghai-Kunming high-speed railway,the adaptability of the reinforcement measures of the CFG pile foundation is analyzed and evaluated.