Research On Design And Construction Technology Of Bailey Beam Bracket For Turnout Continuous Beam Of High Speed Railway

With the rapid development of China's high-speed railway construction and the widespread use of elevated stations,there are more and more roads laid on the bridge.Continuous box beams are often used for turnout continuous beam.The turnout continuous beam is usually asymmetrical in section,complicated in force,difficult in construction and high in technical content.How to ensure the safety of turnout continuous beam construction has always been a hot spot for engineers and technicians.The turnout beam is generally constructed by bracket cast-in-place method.The cast-in-situ bridge construction is a mature and ancient construction method,which is generally adopted in medium and small span bridges.At present,the form of bridge structure is more and more complicated,such as the interchange of highways,viaducts,railway widening turnout continuous beam bridge,and even long and large and multi-spanspans simply supported beam bridges.Cast-in-place bracket method has been used in the construction of special large and medium bridges.Based on the construction of Zunyi East Turnout Bridge project,combined with engineering geological and hydrogeological characteristics,this paper compares several common bracket design schemes,and determine to use and study the beam-column bracket system scheme which is composed of steel pipe columns and Bailey beams.Firstly,the 32m ballast beam is taken as an example to calculate and analyze the force performance of various span combinations,multi-row and multi-layer combination and the method of quickly estimating the Bailey beam combination.This method can quickly complete the preliminary design of the general beam bracket.Based on this,take(7 X 32)m equal width turnout continuous beam and(4 X 32)m widened turnout continuous beam as an example.Using MIDAS to establish a steel pipe column Bailey beam bracket system model,simulates the mechanical behavior of the stent structure system and carries out detailed analysis and verification of its mechanical properties such as strength and stability.In addition,this paper studies the key technologies such as bracket erection,bracket preloading and bracket removal during the construction of the Bailey beam-column bracket Especially for the bracket removal,the Bailey beam overall disassembly construction technology was creatively proposed.The hydraulic jack type grading control was used to compare the traditional lateral drag method,which effectively solved problems of controllability,safety and stability during the process of Bailey beam bracket removal.The transformation of ground operations into beam surface operations reduces the ground environment constraints of the work site,and at the same time creates good economic and social benefits,and can accumulate valuable experience and broaden vision for the construction of similar long-span bridge projects.Figure[89]table[14]reference[59].