Abstract:Combined with engineering example, the construction practice of tunneling is introduced for the tunnel whose entrance stands at harmful geologic conditions of shallow-cover and groove with soft soil. In the course of construction, the techniques were adopted interactively, such as the pre-anchor pile, entrance gate joined with anchor pile, steel tube pile, anchor-tube injected with slurry, continuous underground wall of vertical spraying pile super fore-canula injected with slurry, tubular shed arranged closely, timbering with steel annularity arch, hanging meshwork and anchor bolt spraying, with temporary ob-arch, foresetting ob-arch, built by concrete following closely, floor spraying pile in tunnel done in time and so on. It triumphantly resolved the thorny problems about the entrance of tunnel full floating on soft soil to start digging, excavate, support, build with concrete, etc. For heavy rain tempestuous crack of the temporary shoring, the tracking measure and the construction treatment arc introduced. It can be used for reference to design and construct tunnel under harmful geologic conditions.