关键词: 富水砂层, 大直径泥水盾构, 接收, 钢套筒

Abstract: The shield section of the Karnaphuli Rivercrossing tunnel project in Bangladesh is a doubletube highway tunnel, and both the tunnels are bored using the same shield. The shieldreceiving section of the left line is located in a highlypermeable siltyfine sand strata in coastal area where in conventional shield receiving technology would easily cause sand and water gushing, leading to the failure of shield receiving. Accordingly, to ensure safe and efficient shield receiving and realize secondary launching, steelsleeve receiving technology is adopted. Furthermore, the major risk points of the construction technology are predicted to determine the corresponding prevention and control and emergency 〖HJ2mm〗measures, thus ensuring smooth implementation of largediameter slurry shield steelsleeve receiving. The largediameter 〖ＨＪ2.3mm〗slurry balance shieldreceiving process has been continuously optimized at the tunnel construction site in Bangladesh, and theoretical analysis, simulation test, and method optimization are conducted regarding the sleeve design, deformation control, shaft end reinforcement, portal cutting, shield tunneling monitoring, construction parameter control, portal sealing, and segment stability control at the receiving section. Eventually, key construction technologies for the steelsleeve receiving of a largediameter slurry balance shield suitable for waterrich siltyfine sand strata in coastal areas are formed.

Key words: waterrich sand stratum, largediameter slurry shield, receiving, steel sleeve