The Studies On Construction Technology Of Passenger Special Railway Line Loess Subgrade

Based on reviewing the developments and achievements of high-speed railway subgrade internal and external, this paper in general introduces the engineering characters of collapsible loess in Zheng-xi passenger special railway line, starting up from the concept, basic characters and engineering mechanics characters, this paper summarizes the treatment methods of collapsible loess in Zheng-xi passenger special railway line, it includes the reinforcing principle, construction craft and quality controlling methods of CFG piles, cement soil impacting piles, punching enlarged piles through column hammer, dynamic compaction and cushion mixing geocomposite etc.This paper summarizes and analyzes the filling technology of soil reaction bottom, subgrade under the bottom and the improving soil subgrade of collapsible loess, mainly analyzes the key construction controlling points of the request of subgrade filling-materials, construction craft and technology request, quality controlling and checking.Combining with the design document, this paper studies the monitoring scheme, arranging method and monitoring system design during the subgrade construction. Through the subgrade evaluating, it can ensure the completing of transporting and erecting the beam, ensure the requesting of settlement after construction, determine whether the whole quality of subgrade demanding the request before putting railway.Combining with the construction practice of transition segment in Zheng-xi passenger special railway line, this paper summarizes the construction principles of transition segment, analyzes the construction methods, construction crafts, construction points between subgrade and abutment, between subgrade or cut and cross structures, between subgrade and cut, half-cut and half-filling subgrade, between cut and tunnels. Through the studying and summarizing of the foundation treatment, filling compacting technology, construction monitoring and transition segment of collapsible loess in Zheng-xi passenger special railway line, we get and accumulate the first-hand construction data, exploring the construction technology of collapsible loess subgrade of passenger special railway line, deepen the understanding to high-speed railway subgrade, make some technology storage for the railway subgrade construction methods of our passenger special railway line. At the same time, it can offer a set of complete construction reference data for the technician and special research person who are engaged in the design, construction and maintaining of railway subgrade in passenger special railway line.