深埋隧道穿煤段围岩变形特征研究

Deformation Characteristics of Surrounding Rock of Deep Buried Tunnel through Coal Area

根据某隧道穿煤段(C2煤层)的工程实例,结合围岩位移、围岩内位形、锚杆轴力和钢拱架压力等现场监测,而进行的有关隧道穿过煤段围岩-支护结构的变形特征的分析结果表明:围岩位移变形分为急剧增长、缓慢增长和趋于稳定三个阶段;受高应力与岩体结构的影响,拱顶下沉为水平收敛的3倍,且初期下沉快,下沉时间长;围岩浅部较深部变形快且大,松动圈半径为2.5m～3.0m。该研究结果为深埋隧道穿越煤段设计和施工提供了重要的科学依据。

Based on the engineering practice in the section through coal area（C2 coal bed） of a certain tunnel and combined with the monitoring analysis of surrounding rock displacement, interior displacement of surrounding rock, anchor axial force and steel arch pressure, this paper analyzes the characteristics of deformation of the surrounding rock-support structure of the tunnel through coal area. This analysis gets following results. Firstly, the deformation of surrounding rock displacement can be divided into three phases, which are phase of rapid increase, phase of slow increase and phase of stabilization. Secondly, the deformation is influenced by the great stress and rock mass structure, the speed of the vault settlement with fast speed and long time in previous phase is three times as much as horizontal convergence. Finally, the deformation in low part of surrounding rock is quicker and larger than that in deep part of surrounding rock with relaxation zone at 2.5m-3.0m. This study provides an important scientific basis for optimizing design and construction of deep buried tunnel through the coal area.