Abstract:

The selection and design of a fullsection tunnel boring machine(TBM) and the driving attitude control are critical factors for tunnels with small turning curves. Presently, no universal theoretical basis or guidance methods are available. Therefore, the minimum turning radius applicable for the traditional TBM is determined based on the existing projects and geometrical models. Thereafter, targeted designs of the propulsion and guidance systems of a doubleshield open TBM are prepared, and the structure and construction conditions of the propulsion system are analyzed. Finally, the theoretical method to calculate the inner and outer stroke differences of the doubleshield open TBM propulsion cylinder during turning and the attitude control method during construction are proposed. The following conclusions are drawn: (1) When the turning radius of the tunnel is less than 200 m, a doubleshield open TBM has better applicability than an openshield TBM. (2) The application of the TBM in the Funing pumped storage power station project demonstrates that the proposed theoretical calculation method and attitude control method of the doubleshield open TBM can control the axis deviation of the tunnel in the turning section within the required range.

Key words: fullsection tunnel boring machine, type selection and design, doubleshield open tunnel boring machine, smallturningradius tunneling, attitude control