Stability Analysis Of Surrounding Rock Of Soft Rock Highway Tunnel And Its Supporting Technology

The stability of surrounding rock tunnel construction of analysis is one of the key topics in soft rock highway tunnel, The stability of surrounding rock of evaluation and its supporting technology research has important engineering application value.Taking Shitian highway Mingyazi Specialty tunnel, through the theoretical analysis and field test, FLAC numerical simulation and the method of combining site monitoring, The soft rock highway surrounding rock's stability evaluation and its supporting technology research are completed. Major work and conclusions are as follows:(1) The main factors which affect rock classification are confirmed. They are groundwater, structure surface initial geostress state in shape, the strength and integrity of surrounding rock. Other surrounding rock type field grading methods are gotten.(2) The point load and acoustic testing experiment on the surrounding site classification result of soft rock tunnel are completed. The primary support parameter and working methods are given.(3) Considering two step method, three steps method, the three conditions such as core thickly, the reasonable excavation method FLAC optimization research are completed by establishing FLAC calculation model of soft rock tunnle. FLAC calculation results show that the three steps method when excavating wallrock deformation quantity was good, is small. It is suggested that grade V three steps should be taken in the Mingyazi Specialty tunnle construction of surrounding rock to ensure construction safety.(4) The soft rock tunnel construction reasons deformation monitoring scheme design and site monitoring research work are completed. Results show that the change trend of the deformation of the surrounding rock and FLAC calculation prediction are almost the same change trend, FLAC calculation results are faithful and soft rock tunnel surrounding rock supporting scheme design is reasonable.