Research On The Key Technologies Of Huanglong Tunnel Excavation In Shibai Highway

Shibai highway construction of the tunnel is difficult, especially as the tunnel section islarge, unit footage of the excavation and blasting and harm caused by blasting become large. Inthe excavation, not only the safety, efficiency and effectiveness of blasting construction shouldbe considered, but also good long-term safe and secure of tunnel, hence, blasting constructionshould minimize the retention of the surrounding rock and the damage to the surroundingenvironment. Combined with Shibai highway tunnel construction, on the basis of differentgeological conditions and construction phases, the thesis studies the corresponding blastingtechnology. It is of great importance to guiding the construction, ensuring that the blastingexcavation section and tunnel safety.On the basis of the key construction of a tunnel boring starting point, the thesis selected thesmooth blasting the Huanglong tunneling construction microseism blasting technology, poorgeological section construction process three key technologies in-depth study. Thesis work andresearch results are as follows:In the light of the level of surrounding rock mainly concentrating in III, IV, and V levelof surrounding rock, according to the characteristics of the three surrounding rock, andnever coupled charge coefficient, the surrounding eye spacing, optical burst layerthickness, initiation interval surrounding the eye filled with drugs,the structure ofsmooth blasting parameters is determined. and construction notes is described from thefield construction conditions in order to achieve the optimum blasting results.According to the harm of blasting vibration, the microseism blasting program is putforward. Considering the damping factor analysis, the impact shock elements andproposed relevant solutions are analyzed. With the consideration of maximumallowable amount of charge and undercutting the form of a reasonable interval of timedifference, the excavation program of Shibai highway Huanglong tunnel is proposed.Moreover, the vibration of tunnel is monitored.Based on adverse geological section surrounding rock features, The Huanglong tunnelClass V surrounding rock adopts three-step flow process which follows the principle ofshort footage, weak detonation, the construction of multi-cycle principle. Adoptingmicro seismic blasting excavation, minimum disturbance of the surrounding rock isconsidered.