杨家山隧道为单线双洞隧道,全长5826m。围岩的基本情况为:V级围岩地段全长263m。IV级围岩地段长990m。
按照地质条件及地形因素综合分析,将隧道入口处的洞门设计成偏压式洞门,出口设计成翼墙式洞门:隧道纵断面坡道采用单坡面;采用新奥法施工,衬砌采用复合式衬砌;隧道开挖:III、IV、V级围岩使用短台阶开挖法,微震控制光面爆破法开挖;隧道的辅助施工方法有超前小导管注浆和超前锚杆;隧道通风方式为自然通风。
严格按照设计要求,利用工程类比法和容许应力法结合土压力理论对东门结构进行了设计和检算,同时,在这个过程中对计算模型进行了合理的简化处理,优化了计算结果;在衬砌结构的检算中还应用了杆系结构有限元分析的理论及方法,通过FORTRAN90的计算程序进行了实现,提高了计算精度和效率。经过检算,得知洞门和衬砌结构的安全稳定性满足设计要求。在施工组织设计方面以保证施工安全为主线,施工中注重环保,做到绿色施工;为了确保工期,各分项工程的施工工期和顺序、各施工工序设置以及施工人员的分配和管理都做到了科学合理。
关键词:隧道;新奥法;复合式衬砌;施工组织设计;检算
Abstract
Yang jiashan tunnel is single and double-track railway tunnel, 5826m,full-length. The rock's basic-case: V grade rock section long 263m. IV grade rock section long 990m.
According to geological conditions and comprehensive analysis of terrain factors, the tunnel entrance portal designed to bais-portal and the exit of tunnel portal designed to wing of the tunnel wall portal; the vertical section of tunnel ramp employs one side slope; the tunnel using the construction of New Austrian Tunneling Method (NATM), lining with composite lining;tunnel excavation: V, IV, IIIgrade rock excavation using short step method, blasting micro seismic control excavation; tunnel construction method of assisted with advance Canal grouting and futuristic bolt; tunnel ventilation to their natural ventilation.
In strict accordance with design requirements use of the engineeting analogy and allowable stress method combined with earth pressure theory on the Portal structure design and check calculations, while in the process of the calculation, the model were reasonably simplified to optimize the calculation results; Also, in the process of checking the lining structure is applied on finite element analysis theory and method, the calculation of FORTRAN 90 program was implemented to improve the computational accuracy and efficiency.After checking calculation,that Portal and the lining of the security and stability are to meet the design requirements. The aspects of construction management plan to ensure construction safety as the main line,construction of environmentally conscious, so that the green construction; To ensure that the construction duration, each sub-project of the construction period and order, the construction process and construction workers to set the allocation and management are done reasonable.
Key words: tunnel; New Austrian Tunneling Method; composite lining; construction management plan; check calculations