【摘要】 为研究车辆动荷载作用下深基坑变形规律及稳定性，以洛阳市周山大道下穿开元大道隧道深基坑工程为依托，基于正弦波荷载函数，运用Midas-GTS/NX有限元软件并结合现场实测数据，对车辆动荷载不同作用位置、不同载重以及不同车速作用下深基坑的内撑轴力、灌注桩桩体位移、坑边地表沉降变化等进行了分析。结果表明：车辆动荷载有效影响范围在基坑周边6 m内，若要完全控制基坑变形及保证其稳定性，保通路段围挡布设距坑边不得低于2 m;当车辆载重由2 t增至25 t时，第一道内撑轴力增大了285.37 kN,当三种标准车型的车速由20 km/h增至80 km/h时，第一道内撑轴力分别增大了60.91 kN、62.55 kN、87.45 kN,仅为前一种情况下内撑轴力增加量的21.34%～30.64%;车辆载重为基坑支挡结构受力变形的决定性因素，车速影响次之，且动载最大值出现在车速[20,80]区间中后区域；基坑抗隆起稳定性验算安全系数达4.94,较好满足规范要求。更多还原

【Abstract】 In order to study the deformation law and stability of deep foundation pit under the action of vehicle dynamic load, it used Midas GTS/NX finite element software and combined with on-site measured data to analyse the axial force of internal bracing, displacement of cast-in-place pile and ground settlement change at the pit edge of deep foundation pit under different action positions, different loads and different vehicle speeds of vehicle dynamic loa, based on the deep foundation pit project of Kaiyuan Avenue Tunnel under Zhoushan Avenue in Luoyang. The results show that the effective influence range of vehicle dynamic load is within 6 m around the foundation pit. If the deformation and stability of the foundation pit are to be fully controlled, the distance of fence arrangement in the road section should not be less than 2 m; when the vehicle load increases from 2 t to 25 t, the axle force of the first inner brace increases by 285.37 kN. When the speed of the three standard vehicles increases from 20 km/h to 80 km/h, the axle force of the first inner brace increases by 60.91 kN, 62.55 kN and 87.45 kN respectively, which is only 21.34%～30.64% of the increase of the axle force of the first inner brace in the former case. Therefore, The vehicle load is the decisive factor for the stress and deformation of the retaining structure of the foundation pit, followed by the influence of the vehicle speed, and the maximum dynamic load appears in the middle and rear areas of the speed [20,80] interval; the safety coefficient of anti-uplift stability of the foundation pit is 4.94, which better meets the specification requirements.更多还原