高原铁路隧道地段单元式道床板植筋检算

某高原铁路沿线工程与环境条件复杂,正线以铺设少维护且经济性良好的双块式无砟轨道为主.为解决连续式道床板病害多、修补难度大且对基础变形适应性差等问题,拟采用单元式无砟道床结构.然而,道床结构单元化会削弱道床结构的整体稳定性,需采用植筋加强道床与隧道基础间的连接.为确保植筋设置的可靠性与经济性,基于数值分析方法对道床板与隧...

Calculation of Planting Reinforcement for Unit Track Bed Slab in Tunnel Section of A Plateau Railway

Due to the complexed engineering and environmental conditions,twin-block ballastless track which has less maintenance and better economy are adopted for the main line of plateau railway.The unit structure is used for ballastless track bed in order to solve the problems including cracking in continuous track bed,difficulty in repairment and poor adaptability to foundation deformation.Track bed structure will be weakened because of the unit structure,and the connection between the track bed and the tunnel foundation needs to be strengthened by planting reinforcement.In order to ensure the reliability and economy of planting reinforcement,the calculation and analysis of planting reinforcement setting between the bed slab and the tunnel foundation were carried out by numerical analysis method.The results show that,based on the requirements of shear strength of planting reinforcement,local compressive strength of concrete in invert backfill layer and compressive strength of planting reinforcement glue,the number of planting reinforcement in unit track bed slab of plateau railway tunnel section should be at least 12 HRB400 reinforcement bars with diameter of 16 mm.According to the engineering and environmental characteristics of plateau railway and the requirements of cross-section layout of planting reinforcement,16 reinforcement bars were arranged for each track bed slab in general sections,and 20 for the area within 200 m of the tunnel entrances as well as the longitudinal slope of the line greater than or equal to 25‰.