Fully Prefabricated Assembling Technology of Tsinghuayuan  Tunnel in Beijing Zhangjiakou High speed Railway（京张高铁清华园隧道轨下结构预制拼装技术）

Tsinghuayuan Tunnel of Beijing Zhangjiakou High speed Railway is the first fully prefabricated high speed railway tunnel in China. The supporting structure, subrail structure, and subsidiary structure of Tsinghuayuan Tunnel are all prefabricated in the factory. The strength, deformation and stability of subrail structure are analyzed by numerical simulation method; a kind of three block type of subrail prefabricated structure is put forward according to prefabricated assembling technology; and the subrail space is used to ventilate and rescue under the stability condition. The connection between subrail structure and shield segment is the key to fully prefabricated assembling technology. By introducing the grouting technology and construction keys of subrail structure, the stress on subrail structure and shield segment can be balanced. The results can provide reference for similar projects in the future.