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Calculation of Damage Range of Tunnel Surrounding Rock and Analysis of Influencing Factors under Single-hole Blasting
(Key Municipal Laboratory of Chongqing Colleges for Geological Disaster Reduction in Highway and Water Transportation in Mountainous Areas, Chongqing Jiaotong University, Chongqing 400074)
Abstract In order to solve the inaccurate calculation problem of damage range from tunnel blasting, a calculation method of tunnel surrounding rock damage range under single-hole blasting is proposed based on the D-P criterion and fracture mechanics principle. Based on the relevant project, the damage range of tunnel surrounding rock is calculated under the action of single-hole blasting. The results show that the calculated radius of the crushing zone is 242 mm, which is within the range of measured values; the radius of Fissure Zone Ⅰ is slightly larger than that of the crushing zone, and the radius of Fissure Zone Ⅱ is 1 473 mm, slightly larger than the range of measured values.The calculated results are close to the results of the finite element simulation; The crushing zone of surrounding rock under the action of single-hole blasting is formed at 130 μs, Fissure Zone Ⅰ formed at 220 μs, and the fissure within the Fissure Zone Ⅰ expands at 220-820 μs, so as to form Fissure Zone Ⅱ at 820 μs; The attenuation rates of the vibration velocity in X and Y directions within Fissure Zone Ⅱ and the crushing zone increase with the growth of the distance to the blasting center, respectively; Under the action of single-hole blasting, the main control factors for the radii of the crushing zone and Fissure Zone Ⅰ and the radius of Fissure Zone Ⅱ are the explosive blasting velocity D and Poisson's ratio μ, respectively.
Abstract：
In order to solve the inaccurate calculation problem of damage range from tunnel blasting, a calculation method of tunnel surrounding rock damage range under single-hole blasting is proposed based on the D-P criterion and fracture mechanics principle. Based on the relevant project, the damage range of tunnel surrounding rock is calculated under the action of single-hole blasting. The results show that the calculated radius of the crushing zone is 242 mm, which is within the range of measured values; the radius of Fissure Zone Ⅰ is slightly larger than that of the crushing zone, and the radius of Fissure Zone Ⅱ is 1 473 mm, slightly larger than the range of measured values.The calculated results are close to the results of the finite element simulation; The crushing zone of surrounding rock under the action of single-hole blasting is formed at 130 μs, Fissure Zone Ⅰ formed at 220 μs, and the fissure within the Fissure Zone Ⅰ expands at 220-820 μs, so as to form Fissure Zone Ⅱ at 820 μs; The attenuation rates of the vibration velocity in X and Y directions within Fissure Zone Ⅱ and the crushing zone increase with the growth of the distance to the blasting center, respectively; Under the action of single-hole blasting, the main control factors for the radii of the crushing zone and Fissure Zone Ⅰ and the radius of Fissure Zone Ⅱ are the explosive blasting velocity D and Poisson's ratio μ, respectively.
LI Tao WANG Linfeng LI Song ZHANG Jixu TANG Ning
.Calculation of Damage Range of Tunnel Surrounding Rock and Analysis of Influencing Factors under Single-hole Blasting[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(4): 23-32
2023, Vol. 60 