Research On Milling Dig Combining With Drilling And Blasting Method In Soft Surrounding Rock

With the rapid development of urban rail transit and highway construction, tunnels have become an important method of shorten highway mileage, reduce investment and reduce farmland occupation. Most of the tunnel will cross the weak, broken rock section, landslides, large deformation and rheological engineering disaster are easy happening in the construction, Become a troublemaker in tunnel construction and operation process. Therefore, it is necessary to study on the construction methods for weak surrounding rock.In this paper, based on ShuiTang tunnel of BiWei highway, this study analyzed geological conditions and construction problems in ShuiTang tunnel. Conduct research on construction technology in weak rock, and through the market investigation and contrast, put forward the joint milling dig and drill and blast construction technology. Analyzed the characteristics, construction method, construction result of the method, and come to some meaningful conclusions.1. The joint of Milling digging and drilling and blasting construction technology, combined with precise construction and safe construction of the milling digging machine, and rapid construction, low cost characteristics of drilling and blasting method;2. The joint of Milling digging and drilling and blasting construction technology, should also comply with the role of New Austrian Tunneling Method,"short excavation, fast support, keep measurements, tightly closed, and back into the ring", meanwhile, enhancing the quality of supervision and safety oversight measures;3. The construction sequence of Milling digging and drilling and blasting construction technology, using milling digging machine to shape tunneling contour, the excavation order comply with "from bottom to top, from hard to soft" principle, and promptly applied for initial support structure, and then combination of drilling and blasting method to get rid of the core soil.4、After applying the joint of Milling digging and drilling and blasting construction technology in ShuiTang Tunnel, through construction surveys, and force testing for supporting structure proved the engineering methods may be better adapted to the muddy siltstone and coal seam weak surrounding rock strata construction.