Study on Damage Law of Circumference Rock Mass for Blasting Vibration in the Drivage Daiyuling2nd Small Gabarit Tunnel
|School||Liaoning Technical University|
|Course||Bridge and Tunnel Engineering|
|Keywords||blasting vibration Rock mass damage Acoustic testing Flac3D|
By the means of the theoretical analysis and test research the method of combiningthe blasting vibration of surrounding rock stability, tunnel rock mass cumulative damageattenuation rule peak characteristics were studied. Combining with the Daiyuling2ndtunnel blasting have a large number of blasting vibration measurement, the blastingvibration intensity forecast and the stability of the surrounding rock control problem inthe research.In order to achieve the effect of blasting vibration monitoring and assessment, andthrough the tunnel after excavation in hole initial the first tunneling blasting impactassessment, the establishment of a small clear distance tunnel excavation blastingvibration on the column by disturbance degree relations, in order to achieve the purposeof improving precision. The ultrasonic testing technology, Due to the field experimentfor the determination of many times before and after blasting of rock mass velocity ofsound change, calculated the damage degree of rock mass coefficient, analysis of theblasting of rock mass damage rules, through the blasting vibration and ultrasonic testingexperimental analysis to guide daiyuling2nd tunnel blasting design, to better grasp ofsmall clear distance tunnel excavation design size and construction progress andtechnology provides the scientific reference.Finally using three-dimensional numerical simulation software Flac3D, accordingto wear valley ridge2tunnel excavation of the actual situation, level of surroundingrock, the hole body size, select reasonable design parameters and size standards,3-dnumerical simulation, obtained the wear valley ridge2tunnel column and circumferencebetween rock mass under blasting load and external force under the action of X, Y, Zdirection displacement and stress strain diagram, find the main column and outside themain stress of surrounding rock damage point and the point of pressure value, thus toverify the correctness of the experiment, instruct on-site construction blastingparameters design, master wear valley ridge small clear distance tunnel rock massstrength with blasting driving changes, for wear valley ridge2tunnel excavation andprovides the reliable basis.