Research on Key Construction Technology of Drilling and Blasting in High Altitude Tunnel Near Temple Group
To solve the problems of high vibration risk,insufficient working surface and over-excavation in the construction of the Tongren-Saierlong Expressway Tunnel,the blasting risk identification program is independently developed.Based on the geological background and construction conditions,field tests,numerical simulation,engineering measurement.were adopted to carry out the optimization of technical parameters such as tunnel drilling and blasting hole layout,charge structure and contour line.The field practice shows that the application of the developed vibration risk identification program can greatly improve the ability of vibration risk identification and dynamic control and effectively avoid the risk of disturbance to sensitive people and buildings.According to the effective working surface of the site,the large inclination angle cutting hole was set up,supplemented by the measures such as the expansion holes and the single row of pressure holes on the vault,which fulfils the expectation of improving the work efficiency under the premise of meeting the requirements of hole cutting and rock breaking.By optimizing the charging structure of the surrounding holes and tightening the contour line of the vault,the amount of over-excavation after the risk removal of the tunnel body is effectively reduced.The amount of over-excavation of the initial support sprayed concrete is reduced from 200%to less than 100%.Meanwhile,the dosage is saved by approximately 20kg per cycle,and the economic benefit is remarkable.
tunnelsblastingvibrationweak surrounding rockparameter optimizationdiscrete element analysis
万方数据
维普
