摘要
为解决盾构机在孤石群地层中出洞的难题,本文对花岗岩风化孤石的特点及盾构机在孤石群地层中出洞所面临的地面沉降、涌泥涌砂、姿态跑偏、设备安全的风险进行分析,并从孤石处理、端头地层加固和盾构掘进三方面提出了控制措施。主要得出以下结论:1)采用地下控制爆破技术预处理孤石的关键在于利用岩土之间的介质差异,采用分序爆破的方法制造临空面,从而获得较好的爆破效果; 2)玻璃纤维筋地下连续墙对端头段土体起到整体稳定的作用,在玻璃纤维筋混凝土构件设计时应考虑到其脆性破坏的特征; 3)地面注浆的方法适合于孤石群地层的应用,对端头段土体进行了改良,从而起到了止水和沉降控制的作用; 4)在盾构出洞掘进时,前期准备、掘进控制、辅助注浆等措施都必须细致落实到位,才能确保安全。
In order to solve the problem of the shield machine exiting the hole in the lone rock group, the charac-teristics of the granite weathered lone rock group and the ground subsidence, gush mud and sand, deviation posture of the shield machine, equipment safety when shield machine exiting the hole in the lone rock group are analyzed,and control measures are proposed from three aspects:lone rock treatment, end stratum reinforcement and shield tunnelingexcavation.The main conclusions are as follows:1) The key to pretreatment of lone rock group by under-ground controlled blasting technology is to use the difference of medium between geotechnical and soil, and adopt the method of sequential blasting to produce the vacant surface, so as to obtain better blasting effect;2) The glass fiber reinforced concrete underground continuous wall plays an integral role in the stability of the soil at the head section, and the characteristics of brittle failure should be considered during the design of the glass fiber reinforced concrete component;3) The method of ground grouting is suitable for the application of the lone rock group and the soil in the end section is improved, in this way it playing the role of water stop and settlement control;4) When the shield machine is out of the tunnel, the pre-preparation, tunneling control, auxiliary grouting and other measures must be carefully implemented to ensure safety.
作者
古力
GU Li(Guangzhou Municipal DunJian Underground Construction Engineering Co.,Ltd.,Guangzhou 510030)
出处
《广州建筑》
2018年第6期40-45,共6页
GUANGZHOU ARCHITECTURE
关键词
盾构施工
孤石群
爆破
端头加固
掘进参数
shield construction
lone rock group
blasting
end reinforcement
excavation parameters
