Physical Model Test on the Deformation Behavior of an Underground Tunnel Under Blasting Disturbance
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ORIGINAL PAPER
Physical Model Test on the Deformation Behavior of an Underground Tunnel Under Blasting Disturbance Jiadong Qiu1,2 · Xibing Li1 · Diyuan Li1 · Yuzhe Zhao1 · Chuwei Hu1 · Lisha Liang1 Received: 25 December 2018 / Accepted: 9 September 2020 © Springer-Verlag GmbH Austria, part of Springer Nature 2020
Abstract A physical model test is carried out to simulate the blasting disturbance on the underground tunnel. The test including four blasting events with different blasting locations, where two blasting angles ( |𝛼| ) and two blasting distances (D) are designed. The surface deformation characteristics of the physical model are observed by a DIC system. The deformation responses of four strain components during blasting are obtained. The influences of the blasting location on the surface deformation and failure characteristics are analyzed. The distributions of strain components εx, εy, εxy, and ε1 are obtained for different blasting locations. The different occurrences of failure are compared for cases where the blasthole is at varying locations from the tunnel. The results show that when the blasthole is far from the tunnel, the failure mainly occurs in the vicinity of the blasthole and the failure pattern of the physical model is conical. When the blasthole is close enough to the tunnel and is near the vertical wall, the surrounding rock fail in a V-shape. According to the failure patterns, the anti-disturbance ability of the arch is obviously stronger than that of the vertical wall. Keywords Underground tunnel · Blasting disturbance · Physical model test · DIC · Dynamic response List of Symbols DIC Digital image correlation technique O The tunnel center D Blasting distance α Blasting angle KL The similarity constant of geometry Kρ The similarity constant of density Kσs The similarity constant of static stress Kσd The similarity constant of dynamic stress Kµ The similarity constant of Poisson’s ratio Kε The similarity constant of stain KEs The similarity constant of static Young’s modulus Kσc The similarity constant of strength Kc The similarity constant of P-wave velocity Kv The similarity constant of velocity σs Static stress * Xibing Li [email protected] 1
School of Resources and Safety Engineering, Central South University, Changsha 410083, China
Shenzhen Key Laboratory of Deep Underground Engineering Sciences and Green Energy, Shenzhen University, Shenzhen 518060, China
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σd Dynamic stress σx Horizontal stress σy Vertical stress σhmax Maximum horizontal principal stress σhmin Minimum horizontal principal stress σv Vertical principal stress εx Horizontal strain component εy Vertical strain component εxy Shear strain component ε1 Maximum principal strain UCS strength Uniaxial compressive strength SZ Strain growth zone RZ Red strain concentration zone LVW Left vertical wall
1 Introduction With the gradual exhaustion of resources close to the surface, the depths of underground excavation projects have become deeper (Li et al. 2017; Wang et al. 2019, 2020b
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