双护盾TBM开挖膨胀岩洞段施工应用技术研究  

Tunnel Excavations in Expansive Shale Rock Mass Using TBM

作　　者：王彦峡[1] 辛风茂[1] 章跃林[1] 

机构地区：[1]中水北方勘测设计研究有限责任公司,天津300222

出　　处：《土工基础》2012年第4期36-39,共4页Soil Engineering and Foundation

摘　　要：某膨胀岩洞段,围岩强度低,抗风化能力弱,水理性质不良,易发生吸水膨胀失水收缩现象。基岩洞段褶皱、褶曲发育,地层产状变化大,围岩呈层状～碎裂结构。双护盾TBM开挖后,隧洞发生不同程度的坍塌与塌方。现采取"三低一连续"(低推力、低转速、低贯入度;快速连续掘进)快速封闭围岩,严格控制施工用水;使用化学材料灌浆固结围岩等施工应用技术,成功通过了泥质软岩类隧洞长地段,为今后双护盾掘进机施工提供了宝贵经验,社会和经济效益巨大。Expansive shale rock masses have low strength, high weathering, and low resistance to the water and moisture. When the tunnel is excavated in this rock mass using a Tunnel Boring Machine （TBM）, large deformations will occur in the tunnel cross sections. In addition, if the humidity in the excavation changes rapidly, expansion and contraction will occur in the expansive shale. Along the proposed tunnel excavation alignment, the rock mass is severely folded due to rapid change of dip directions. The broken zones along the daylighting joint direction are very well developed. The jointed rock mass is usually dis- continuous. When a tunnel is excavated using TBM, various collapses might occur at the working surface due to stress relief and re--distribution. In order to reduce this disturbance to the rock mass, the excavation technique should be： ＂Three Lows and One Continuous＂： Low Thrust Force, Low Drill Bit Rotation; Low Penetration and Quick Continuous Forward. The side blade of the TBM should be adjusted so that a larger tunnel cross section can be created. The exposed rock mass needs to be quickly sealed off and the water consumption during the penetration should be strictly controlled. During construction, the TBM excavation guidance documents were improved and modified, i. e. , longitudinal and radial pilot grouting holes were crea- ted at the proposed shielded zones so that the rock mass stability could be improved by chemical grouting. These techniques were successfully utilized in argillaceous soft rock masses with a total linear excavated length of 13,532 meters. This length consists of 67%of the total tunnel excavated in the project.

关 键 词：TBM 膨胀岩 变形效应 层间错动 碎裂结构 结构面组合 应力重分布 纵环向导洞 化学材料 灌浆固结 

分 类 号：TU457[建筑科学—岩土工程]