土压平衡式盾构施工中“理想状态土体”的探讨

On the "Ideal Soil" in the Earth Pressure Balanced Shield Tunnelling

提出了土压平衡式盾构施工“理想状态土体”的概念:较低的渗透性,相对适中的压缩性,较小的抗剪强度,一定的流动性。使用外加剂最好的效果就是使开挖下来的天然土体经过改良后接近“理想状态土体”。应将盾构掘进中喷涌、结泥饼、开挖面失稳、排土不畅等因为土体性质不良导致的施工故障发生可能性降到最低。还对非理想状态土体引起的常见盾构施工问题进行了概述。通过理论和实践的研究,确立了评价理想状态土体的物理力学指标,并认为只要有效、有针对性地使用外加剂,将土体的物理力学性能调整到分析范围,可将施工难题控制在最小的发生概率之内。

This paper puts forward the concept of the ＂ideal soil＂ in the shidd tunnelling construction, supposing that the best result to use the addition is to make the natural rail from the surface to an ＂ideal soil＂ through improvement, otherwise it will cause many problems in the construction. The author establishes the indexes to evaluate the physical mechanics of the ideal soil through a research in theories and practices. Finally, ＂the constant problems that caused by the natural soil are summarized.