明挖基坑内地铁矿山法隧道进洞的设计与施工

The Design and Construction of the Entrance to Subway Mined Tunnel from Deep Foundation Pit

研究目的：地铁区间隧道施工中，经常会有从明挖基坑中直接进行矿山法隧道进洞的情况，为保证明挖基坑的稳定和矿山法隧道进洞段施工的安全，需要从设计和施工组织上采取必要的措施，本文以广州地铁三号线五山站～华师站区间工程的成功实施为例，介绍了基坑中矿山法隧道进洞的设计与施工要点，其相关经验可为今后类似工程提供借鉴。研究结论：（1）为保证矿山法隧道进洞施工的安全，需要对隧道洞门段地层进行必要的超前加固，并加强隧道初期支护；（2）在基坑开挖过程中穿插进行矿山法进洞施工的部分工序，合理组织工序衔接，可以减少重复工作，加快隧道进洞，既保证明挖基坑的稳定，又使矿山法隧道安全进洞。

Research purposes： In construction of subway tunnel in section, it is popular that the entrance to the mined tunnel is directly from deep foundation pit. For the stability of open cut deep foundation pit and the safety of mined tunnel entrance, it is necessary to take the measures in design and construction organization. Based on the successful completion of the tunnel in the section between Wushan Park Station and Huashi Station of line 3 of Guangzhou metro, in this paper, the introduction is given to the key points of design and construction of entrance to the mined tunnel from the foundation pit and its experience can be as the reference to the similar works. Research conclusions： （ 1 ） For ensuring the safe construction of the entrance to the tunnel, it is necessary to take measures of reinforcing the bed of entrance to the tunnel in advance and strengthening the primary support to the tunnel. （2） During the excavation of foundation pit, some construction works for the entrance to the mined tunnel can be done through reasonable construction organization for not only reducing the repeated works and speeding up the construction of the entrance to the tunnel, but also for ensuring the stability of open cut foundation and making the tunnel safe entry.