On basis of the survey practice in Tian-Hua shield-bored running tunnel on line 3 of Guangzhou Metro,the author presents the survey works in the construction of the Shield-bored Metro tunnels,analyzes on the influence of the traverse survey accuracy on the holing-through accuracy and recommends some countermeasures to improve the holing- through accuracy.

This paper analyzes the breakthrough precision criteria of GPS straight tunnel,and discusses the interior and exterior reliability criteria of GPS point,and gives out the breakthrough precision and reliability criteria for the optimization and design of GPS network.

And the authors also give their own opinion on how to improve the breakthrough precision of tunnel to control underbreak and overbreak of tunnel excavation.

Through modifying the Lajtai’s theory,the failure strength criteria of such rock mass were proposed.

On the basis of model testing results,the deformation and fracture mechanism of brittle rockmass containing coplanar close intermittent joints under direct shear condition are analyzed,and the criteria of fracture initiation strength and failure strength of such rockmass are proposed.

Based on the theory of leveling error, the calculating formulas for the increment of lateral penetrating accuracy by the layout of ground and underground single guide lines added with spinning top rakes are derived strictly.