【摘要】 为研究冲击荷载对直墙拱隧道的影响，制备大尺寸钢纤维混凝土隧道试样，使用自研双向受压摆锤动力冲击系统开展冲击破坏试验，并采用超动态信息采集系统记录冲击波和应变，并结合数字图像相关技术(DIC)表征表面应变和位移场。竖向施加0.6 MPa预应力，2 000 kg摆锤提升高度至150 mm冲击试样，结果表明：摆锤施加波幅振荡衰减的低频冲击波；直墙拱试样拱肩和拱脚4个位置出现裂缝，两拱肩处裂缝沿着直墙拱向冲击波方向延伸，并在洞室内部拱顶形成一条环向裂缝；峰值、塑性应变均以拉应变为主，峰值应变环向较大，径向与轴向较小，试样内部塑性应变左拱肩最大；拱顶变形位置附近应变计的塑性应变和峰值应变比值较大；DIC应变云图显示，在小于200μs时间内试样拱肩、拱脚4条裂缝萌生、贯通，竖向应变变化最大，竖向应变集中区与裂缝形态相吻合，水平应变集中区主要出现在拱肩位置，剪切应变集中分布区主要分布在各裂缝的拐折处。更多还原

【Abstract】 In order to study the effect of impact load on straight-wall arch cavern and surrounding rock, large-scale steel fiber reinforced concrete specimens were prepared, and a self-developed pendulum impacting system with biaxial stresses was used to carry out impact tests. A super-dynamic information acquisition system was used to record the impact force and internal strain, and digital image correlation technology was used to characterize the surface strain field. 0.6 MPa stress was applied vertically, and the height of 2 000 kg pendulum was raised to 150 mm. The results show that: The shock wave with amplitude attenuation was a typical low-frequency shock wave. Four cracks appeared in the spandrel and foot of the straight wall arch specimen, and the cracks at the spandrel were connected by a circumferential crack on the vault of the cavern. The internal peak strain and plastic strain are mainly tensile strain, compressive strain distributed near the left foot of the tunnel. The peak strain was larger in the circumferential direction, smaller in the radial and axial direction. And the plastic strain in the left spandrel was the largest. And the vault was prone to plastic deformation which can not be recovered through peak or plastic strain, but the ratios of plastic strain to peak strain in the vault were all larger. DIC strain cloud map showed that within less than 200 μs, the four cracks of spinner and foot of the sample were formed and connected, and the vertical strain changed the most, the vertical strain concentration area was consistent with the fracture morphology, the horizontal strain concentration area mainly appeared at the spinner position, and the shear strain concentration area was mainly distributed at the bend of each crack.更多还原