Tunnel construction method using pre-support and post-support and apparatus suitable for same

A tunneling method using an internal pre-support member and a post-support member, the tunneling method comprising the steps of:

• (a) excavating a pilot tunnel in a main tunnel to be constructed;
• (b) radially forming a drilled hole from an excavation surface of the pilot tunnel to a tip end of the internal pre-support member of the main tunnel at a plurality of locations in the pilot tunnel to install the internal pre-support member;
• (c) inserting the internal pre-support member into the drilled hole,
• (d) grouting and curing to fix the internal pre-support member;
• (e) excavating the main tunnel in stages in a longitudinal direction along an excavation line of the main tunnel and primarily spraying shotcrete to an excavation surface of the main tunnel;
• (f) drilling a hole for receiving the post-support member on the excavation surface of the main tunnel to which the shotcrete is primarily sprayed;
• (g) installing the post-support member at the hole between a plurality of the internal pre-support members on the excavation surface of the main tunnel to which the shotcrete is primarily sprayed;
• (h) fixing the post support member using grout to completely fill a space between the hole and the post support member for bonding the post support member to the hole such that an existing structure of the main tunnel is reinforced;
• and
• (i) connecting the internal pre-support member and the post-support member with a plate type support member,
• wherein a length or a diameter of the pre-support member is larger than a length or a diameter of the post-support member and wherein the post support member comprises at least one of a steel rod, a hollowed rock bolt, a steel pipe, a perforated steel pipe, a glass fiber reinforced plastic (GRP) bolt, or a swell bolt.