大断面隧道机械化施工支护结构设计方法——以郑万高铁湖北段隧道为例

Design Method for Support Structure of Large Cross-section Tunnels in Hubei on Zhengzhou-Wanzhou Railway Constructed by Mechanized Means

为了建立适用于大断面隧道机械化施工技术的支护结构设计方法,基于极限平衡法推导了考虑3种超前支护措施(超前管棚、掌子面锚杆和掌子面预注浆)的三维掌子面稳定系数计算公式;基于大量的深埋隧道形变压力现场实测数据,通过多元非线性回归分析方法,拟合推导了基于BQ系统的整体形变压力计算公式及局部形变压力计算公式,并建立了对应的洞身支护结构设计模型。根据提出的支护结构设计方法,给出了郑万高铁隧道掌子面超前支护参数及初期支护参数,通过工程应用,证明了该参数的合理性及本文设计方法的实用性。

In order to establish a support structure design method suitable for mechanized construction of large crosssection tunnels,the calculation equation of the stability coefficient of the tunnel face considering three kinds of advance support measures(advance pipe roofing,face bolting and pre-grouting)is deduced based on the limit equilibrium method.Then,the calculation equations of the overall displacement pressure and the local displacement pressure are derived based on the multiple nonlinear regression analysis method,the BQ system and a large number of field test data of displacement pressure of deep-covered tunnels.Later,according to the support structure design method established,the advance support and primary support parameters of tunnels on Zhengzhou-Wanzhou high-speed railway are presented,and the rationality of the parameters and the practicability of the proposed method are proved by practical application.