TREATMENT METHOD FOR SIDE ROOF COLLAPSE OF WATER-BEARING BROKEN SOFT ROCK TUNNEL

The present disclosure discloses a treatment method for side roof collapse of a water-bearing broken soft rock tunnel, including the following steps: sealing a water bursting excavation face of crushed surrounding rock with shotcrete and rock bolts; excavating the excavation face on one side with less water inrush until an excavation depth extends beyond a water-bearing crushed collapse region, and mounting an arch frame synchronously; burying a steel pipe in a sidewall close to a region with great water inrush within the main tunnel on the side with less water inrush, and grouting the steel pipe; driving advanced small ducts into the remaining excavation face of the upper bench, and excavating the remaining excavation face. According to the present disclosure, during construction, excavation is performed first on the side with less water inrush; the region with great water inrush in the tunnel is grouted, and meanwhile, the advanced small ducts are driven into the excavation face and grouted, thereby forming a cross-stratified slurry network. Thus, the stability of the grouted region is further enhanced and further collapse of the region with water inrush is avoided. In addition, the excavation face with less water inrush is excavated first without waiting for the completion of the collapse treatment, so that the construction period is shortened. DRAWING - Fig 1