高级检索

近场爆炸荷载作用下盾构隧道损伤模式研究

Research on Damage Modes of Shield Tunnel under Near-field Explosion Load

  • 摘要: 为了研究近场爆炸荷载作用下盾构隧道的损伤机理,选用23 kg TNT,中心距离300 mm的爆炸工况,采用有限元手段对于拱顶、拱肩、拱腰、拱脚、拱底等五个位置的近场爆炸工况进行分析,总结盾构隧道损伤分布规律。通过LS-DYNA有限元分析发现,在近场爆炸作用下,盾构隧道管片出现显著损伤,其中内侧损伤最为显著,面积最小值达54 dm2,其次是管片截面和背面,损伤面积最小值分别为38 dm2和32 dm2;当爆炸点位于拱肩和拱脚时,损害面积最大,因爆点靠近管片环缝和纵缝连接处,该区域的强度相对较低,冲击波反射现象增加;一字型接缝位置(环缝、纵缝)受到近场爆炸荷载时,损伤呈对称圆形分布;而接缝交点位置受到近场爆炸荷载时,损伤显著增加且分布不均。

     

    Abstract: In order to study the damage mechanism of shield tunnel under near-field explosion load, the explosion condition of 23 kg TNT with the center distance of 300 mm was selected, and the near-field explosion condition of five locations such as vault, spinner, arch, arch foot and arch bottom was analyzed by finite element method, and the damage distribution law of shield tunnel was summarized. Through LS-DYNA finite element analysis, it is found that under the action of near-field explosion, there is significant damage to the shield tunnel segments, among which the inner side damage is the most significant, with the minimum area of 54 dm2, followed by the section and back of the segment with the minimum damage area of 38 dm2 and 32 dm2 respectively. When the explosion point is located at the spandrel and arch foot, the damage area is the largest. Because the explosion point is close to the joint of the ring joint and the longitudinal joint of the segment, the intensity of this area is relatively low, and the reflection of the shock wave increases. When the joints (annular joints and longitudinal joints) are subjected to near-field explosion load, the damage distribution is symmetrical and circular. However, when the joint intersection is subjected to near-field explosion load, the damage increases significantly and is unevenly distributed.

     

/

返回文章
返回