Maintenance generally enhances bridge performance. However, the collapse of the I-35 W Highway Bridge over the Mississippi river in 2007 highlighted that maintenance work could generate adverse traffic load effects (LEs), resulting in a higher probability of structural failure. This study investigated the impact of maintenance work on the lifetime traffic loading and structural safety of long-span bridges. Maintenance works are classified according to their potential for causing lane closures and the presence of construction trucks on the bridge deck, wherein five loading scenarios are identified. Site-specific weigh-in-motion (WIM) data are used for traffic microsimulation over a long-span girder bridge carrying four-lane unidirectional traffic. Modified low-, medium-, and high-traffic volumes based on WIM data are considered. The traffic LEs were analyzed under the five scenarios and three traffic volumes, and the bridge safety was probabilistically evaluated with and without considering the impact of maintenance work. We showed that low and medium traffic flows with lane closures remain in free-flow states, considering that maintenance work poses no impact on lifetime LEs. However, under high traffic volume, lane closures cause congestion, and LEs under the one-lane closure scenario are even more adverse than those under slow-moving homogeneous congested traffic (the governing form in conventional design standards for long-span bridges). Furthermore, without considering the impact of maintenance work under high traffic volume, lifetime LEs may be underestimated by over 13% and the reliability index may be significantly overestimated. Consequently, maintenance works should be planned and executed so as to avoid undesirable loading situations.

维护通常可以增强网桥的性能。但是，2007年密西西比河上的I-35 W公路桥梁的倒塌突出表明，维护工作可能会产生不利的交通负荷影响（LE），从而导致结构故障的可能性更高。这项研究调查了维护工作对大跨度桥梁的终生交通负荷和结构安全性的影响。维护工作根据其可能造成车道关闭的可能性以及桥面平台上施工卡车的存在进行分类，其中确定了五种装载方案。特定于站点的运动中重量（WIM）数据用于承载四车道单向交通量的大跨度梁桥上的交通量微仿真。考虑基于WIM数据修改的低，中和高流量。在五个场景和三个交通量下对交通LE进行了分析，并在不考虑维护工作影响的情况下，概率性地评估了桥梁安全性。考虑到维护工作不会影响生命周期的LE，我们证明了封闭车道的中低流量仍保持自由流动状态。但是，在高流量下，封闭车道会造成拥堵，而在单车道封闭情况下的LE甚至比缓慢移动的同类拥堵交通（大跨度桥梁的传统设计标准中的控制形式）下的LE更为不利。此外，在不考虑高流量下维护工作的影响的情况下，寿命LE可能会被低估13％以上，可靠性指标可能会被大大高估。最后，