Abstract:

The shallow tunnel section on Wusi Square StationFushansuo Station on Line No. 2 of Qingdao Metro, closely crossing underneath existing underground commercial street (rectangular frame structure), is constructed by mining method. The tunnel is located in complex geological conditions of upper waterrich and sandy strata and lower hard rock. The rational support parameters and technologies are the key to closely crossing. A series of technologies, i.e. deephole grouting reinforcement, superlong pipe roof support, vibration reduction blasting, realtime monitoring and numerical calculation and simulation, are adopted, so as to control the settlement of commercial street and surrounding rocks, guarantee the operation of commercial street and reduce the construction risk of tunnel. Finally, good effects have been achieved.

Key words: Qingdao Metro, shallow mining method, closely underneath crossing, complex strata, deephole grouting, superlong piperoof support, vibration reduction blasting, automatic monitoring