The longitudinal milling and dredging machine is analyzed in detail

At present, the main construction methods for excavation of soft broken surrounding rock are divided into traditional new Austrian method and mechanical roadheader method. The new Austrian tunneling method has the disadvantages of large disturbance, not suitable for accurate construction and easy to cause cave collapse. However, the construction of expensive TBM and shield tunneling machine has high construction cost and large one-time investment, which has certain limitations for small and medium-sized projects. Therefore, this paper combines the construction technology of hydraulic milling and excavating machine, which has gradually developed in recent years, with the construction technology of traditional drilling and blasting method, and carries on the applicability research. The following conclusions are reached:

1. The combined construction technology of milling and digging with drilling and blasting excavation has the characteristics of strong adaptability, fast construction speed, simple and convenient operation, safe construction and low cost, which can be applied to the construction of most weak surrounding rock sections.

2. The combined construction technology of milling and digging with drilling and blasting excavation also follows the new Austrian construction principles of "short excavation, fast support, workage measurement, tight sealing and early ring formation", and also emphasizes flexible application of this technology in tunnel tunneling according to local conditions. The excavation height and blasting equivalent of steps are determined according to specific geological conditions of surrounding rocks and groundwater conditions.

3. The joint construction technology of milling and digging with drilling and blasting excavation of hydraulic milling and digging machine under mine should not only emphasize the reasonable selection of construction machinery and equipment and the reasonable determination of step size, but also pay attention to the training and management of technical personnel, strict quality assurance measures, strict safety measures and strict construction discipline.

3. The combined construction technology of milling and digging with drilling and blasting excavation has been applied to the coal measure strata construction of reservoir tunnel, and has obtained good results. It has the characteristics of small disturbance to surrounding rock, and has great advantages in the excavation contour round and controlling overexcavation and underexcavation.

4. In this paper, deformation monitoring and internal force monitoring are carried out respectively for two typical sections of reservoir tunnel with different construction techniques. It is proved that the combined construction technology of mining hydraulic milling and excavating machine and drilling and blasting excavation in the same weak broken surrounding rock stratum can cause less disturbance of surrounding rock and make the construction safer.

5, the construction process is fast, low labor intensity, easy to construction management, improve efficiency, energy saving and consumption reduction; The construction site is clean, the civilized construction level is improved, and the social benefits are remarkable; At the same time, the project quality, construction progress, technical breakthroughs and civilized construction were highly evaluated by the community, and won good social benefits. It is worth promoting and using.