中间风井内盾构隧道管片局部拆除方案研究

为解决苏州地铁盾构隧道直接掘进通过围护结构为玻璃纤维筋连续墙、内部充填土体的明挖风井后, 位于地下空间下方的 深埋盾构隧道与区间风井间封堵困难、整环管片拆除风险过大的问题, 创新性地提出规避风险的管片局部拆除方案, 即盾构隧道 上部管片拆除后增加梁板形成倒“Ω”结构。 对该方案施工中涉及的影响因素进行分析研究, 重点探讨管片局部拆除方案及倒“Ω” 结构的可行性, 并提出多方面的控制措施, 最后对倒“Ω”结构进行理论计算分析。 结果表明: 在地铁区间风井内盾构隧道管片全 环拆除施工风险过大的情况下, 可以通过拆除盾构隧道上部管片并增加梁板形成倒“Ω”结构的方案解决风险过大问题。 此外, 结 合现场施工验证该创新方案的可靠性。

Partial Demolition Scheme for Shield Tunnel Segment in Middle Ventilation Shaft

The sealing of deep shield tunnel and ventilation shaft is difficult and the demolition of a whole segment is of great risk after the Suzhou Metro shield tunnel directly passes through underground diaphragm wall with retaining structure of glass fiber and open-cut ventilation shaft filled by soil. Hence, a partial demolition scheme for segment is put forward, which demolishes upper part of segment and sets a horizontal beam to form a reverse-Ω structure. And then the influence factors of the construction is analyzed, the feasibility of the scheme is discussed in detail, some control measures are put forward, and the theoretical calculation and analysis are carried out on reverse-Ω structure. The results show that the scheme mentioned above is feasible and can reduce the construction rick effectively.