Abstract:

Abstract:   Taking the shield launching and arriving at Yuanshen Road intermediate ventilation shaft in No.2 bid section of second phase of No.9 Line of Shanghai Metro as an example, the author presents the technological problems including extradeep cover, confined water, freezing method, curve with small radius, shield parallel moving along curve path in ventilation shaft and shield tunnelling near buildings. After scheme optimization, practical countermeasures including strengthening waterproofing at tunnel portal, adoption of launching along tangent and arriving with compensation and advance reinforcement of nearby building was put forward, which ensures the successful launching and arriving of the shield.

Key words:  shield, complex geologylaunching and arrivingextradeep coverconfined watercurve with small radiusfreezing methodgreasy polyurethane