为确保盾构始发与到达的顺利进行,避免施工过程中出现端头土体失稳现象,从而引发地表沉陷、塌方等工程事故,作者在分析了现有端头加固理论模型的优缺点后,基于端头加固土体的力学和数学模型,提出了基于强度理论的荷载等效模型和基于稳定性理论的砂性土端头滑动模型,给出了端头土体纵向加固范围计算公式。同时,根据盾构设备的几何构造特征及端头土体的渗透性要求,提出了盾构始发与到达端头土体纵向加固范围＂几何准则＂。该研究方法综合考虑了端头土体的强度、稳定性、渗透性及盾构设备的几何尺寸对盾构始发与到达的影响,研究结果对指导施工及反馈盾构隧道设计具有重要理论与实际意义,也可为类似研究提供参考。%In order to keep the safety during TBM＇s launching and break through and avoid larger ground settlement or collapses happening at the joint areas of TBM＇s launching and break through, the relevant mechanical and mathematical models are established in this paper after making an detail analysis of advantages and disadvantages of current theoretical models for strata improvement at the jnints areas. And the theoretical equations of tunnel longitudinal reinforeement scacles based on strength and stability theories are deduced. At the same time, according to geometrical characteristics of TBM and permeability requirement of improved strata, geometric principles along funnel longitudinal improvemenl scales are also proposed. The methods adopted in this paper consider the influence induced by strength, stability, permeability of improved strata and the geometrical characteristics of EPB TBM, all these results are of not only theoretical and constructional importance for tunnel projects by EPB TBM, but also improving our tunnel design ideas and being referred for other similar studies.
展开▼
