Abstract:

Advance timbering, an important component of open shield, plays a crucial role in supporting the tunnel, bearing the earth pressure and preventing the collapse. In the paper, the function, configuration, thrust calculation and cylinder selection of the advance timbering of 6.22 m open shield used in No. 6 line of Beijing Metro are presented. Furthermore, a finite element model for the advance timbering is established based on 2 typical working conditions and the stress and deformation contour plots are generated. According to the analysing results, improvement measures are proposed and carried out. The boring of the prototype shield proves that the advance timbering designed is feasible and reliable.

Key words: open shield, advance timbering, design