Abstract:

he effect on existing metro station structures caused by the construction of new risk underground project is studied by the finite element program and the finite difference program. The analysis of displacement caused by the construction of new contact channel No.3 between double-floor windtunnel and southwest entrance structure is expounded on the characteristics of safety evaluation of approaching project construction using different numerical methods. The evaluation conclusions are produced by checking the carrying capacity of existing structures combined with the survey of existing structures status. The displacement control indices are proposed that the settlement and uplift of the ground surface should not exceed 7 mm & 8 mm, respectively; the uplift displacement of the station soleplate and the relative uplift displacement of structures on both sides of settlement joint should be controlled in 7 mm & 2 mm, respectively; the uplift displacements of the tracks and track cross level should not exceed 5.8 mm & ±0.6 mm, respectively. The existing metro structures will be safe after the new-built tunnel is constructed if displacement controls are in the above-mentioned ranges.

Key words: shallow tunnel, existing metro station structures, numerical method, safety evaluation