The construction of new buildings very close to existing tracks, with heavy commuting traffic, requires careful design. Such projects must be accompanied with noise and vibration reduction measures. The practical case here considered has been analysed by first assessing the existing situation prior to construction (type of soil and traffic). In a second stage, we have proposed and quantified solutions to reduce vibration and ground-borne noise levels inside the buildings. A 2.5D FEM/BEM commercial software (Mefissto), developed by CSTB, has been employed in what is a very challenging numerical context: multi-layered ground, large multi-levels buildings, large frequency range (10–250 Hz). In every situation, the use of an original 2.75D approach leads to the low frequency noise levels inside the buildings. As the trackwork cannot, in this case, be modified the solutions tested consist in inserting different types of barriers in the ground or in inserting either spring of resilient bearings (decoupling) in the lower part of the structure. Results are compared to target values in terms of vibration and ground-borne noise levels selected in order to limit dwellings occupants’ annoyance. Satisfactory results can only be achieved with the use of the decoupling solution.

新建筑的建造非常接近现有轨道，上下班交通繁忙，需要仔细设计。此类项目必须伴有降噪和减振措施。通过在施工前首先评估现有状况（土壤类型和交通状况）来分析此处考虑的实际案例。在第二阶段，我们提出并量化了解决方案，以减少建筑物内的振动和地面传播的噪声水平。由CSTB开发的2.5D FEM / BEM商业软件（Mefissto）已在具有挑战性的数值环境中使用：多层地面，大型多层建筑，大频率范围（10–250 Hz）。在每种情况下，使用原始的2.75D方法都会导致建筑物内的低频噪声水平。由于在这种情况下跟踪工作无法进行，要进行修改，要测试的解决方案包括在地面上插入不同类型的屏障，或者在结构的下部插入弹性轴承的弹簧（去耦）。将结果与选定的振动和地面传播噪声水平的目标值进行比较，以限制居住者的烦恼。只有使用去耦解决方案才能获得令人满意的结果。