综合管廊天然气舱内爆炸对邻近地铁隧道的影响研究

Effect of Explosion in a Gas Pipeline Compartment of a Utility Tunnel on Neighboring Metro Tunnels

  • 摘要: 针对综合管廊与城市地铁共同建设的方案,文章运用 AUTODYN软件对综合管廊天然气舱内爆炸对邻近地铁隧道的影响进行了数值模拟分析。分析结果表明:在综合管廊天然气舱室天然气浓度达到 10%时,200 m防火分区内 TNT当量为 41.6 kg;爆炸冲击波对圆形地铁隧道的拱顶和拱腰影响较大,需采取必要的防护措施;当周围土体为砂土材料,综合管廊处于圆形地铁隧道正上方且前行方向一致时,管廊与地铁隧道之间的垂直间距越大,爆炸冲击波对地铁隧道的影响越小;当垂直间距为 7.2 m时,最大动拉应力为 1.86 MPa(包括隧道管片静态应力,约为 1 MPa),略小于地铁隧道的抗拉强度设计值 1.89 MPa,最大振动速度与最大位移均符合相关规范以及结构稳定性要求,因此建议管廊与地铁隧道的垂直间距不小于 7.2 m。

     

    Abstract: In this paper the numerical simulation analysis of the effect of explosion in the gas pipeline compartment of a utility tunnel on neighboring metro tunnels was conducted using the software AUTODYN. The results show that the TNT equivalent in a fireproof partition with length of 200 m is 41.6 kg when the gas concentration in the gas pipeline compartment reaches 10%; the blast wave has much effect on the crown and arch waist of the round metro tunnel and it′s necessary to take some protective measures in both areas; when the surrounding soil is sand, the utility tunnel is above the round metro tunnel and their alignments are in the same direction, the greater the vertical spacing between the utility tunnel and the metro tunnel, the smaller the effect of the blast wave on the metro tunnel;when the vertical spacing is 7.2 m, the maximum dynamic tensile stress is 1.86 MPa (including the static stress value of 1 MPa in the tunnel segment) and it is slightly smaller than the designed tensile strength of metro tunnel (about1.89 MPa). The maximum vibration velocity and the maximum displacement meet the structural stability requirements, so it is suggested the vertical spacing between the utility tunnel and metro tunnel shall not be less than 7.2 m.

     

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