The ongoing project of Diantou tunnel was taken as an example in this research to analyze the influence of ve-hicle load on the surrounding rock and the road .The results show that :(1 ) Excavation leads to the subsidence of tunnel vault and waist as well as the uplift of the bottom part .The application of initial support can effectively restrain the defor-mation of surrounding rock of tunnel and reduce the displacement of surrounding rock caused by vehicle load ;(2 ) The excavation of the middle of tunnel results severe surface settlement when using the three step excavation method .The ap-plication of primary support can reduce the surface settlement caused by vehicle loads and excavation .Therefore ,the overall deformation of tunnel is larger under the traffic load without the primary support .Besides ,the pavement cracks may emerge in this condition .%依托在建的甸头隧道,开展隧道开挖是否考虑初期支护下车辆荷载对围岩及大西二级公路的影响研究.结果表明:隧道开挖引起隧道顶部及腰部发生沉降,底部发生隆起,初衬的施加可以有效抑制隧道周边围岩的变形,且可减小车辆荷载对围岩位移的影响;三台阶开挖时,隧道中部开挖引起地表发生剧烈沉降,初衬的施加可以减小地表的沉降,减小车辆荷载对地表沉降的影响.因此,无初支的情况下,当公路有车辆通过时,隧道整体变形较大,路面可能由于差异沉降产生裂缝.
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