Analysis of ground-borne noise and vibration levels generated by buses

Abstract

In a dense urban environment, vibrations and ground-borne noise generated by buses is an increasing problem in the same way as that generated by urban mass transit. Furthermore, it is very hard to mitigate vibration levels using a wave impedance barrier or trenches due to the short distances between roads and buildings and network congestion. Modifying building foundations in order to place spring boxes or resilient plots is generally very difficult. In most cases, significant reductions in vibrations and ground-borne noise are mainly achieved by to maintenance operations performed on the road’s surface instead of replacing rolling stock or a decreased speed limit. In the Paris region, particularly high levels appear in so-called “Haussmannian” buildings with beam iron structures and lightweight floors. Few data are available in the literature, unlike the rail sector where the infrastructure manager and the operator are usually easily able to find mitigation solutions. With road complaints, inhabitants call operators, which do not directly control the impact of their rolling stock on the building, its floors and their intrinsic characteristics. Therefore, RATP built a database fed with measurements taken in the Ile-de-France region despite very different experimental conditions. One of the purposes of this database is to identify similar behavior and reproducible gains through, for example, the renewal of the road surface. In this paper, a specific case of the Haussmannian building is detailed. The behaviors of time histories and frequencies are compared based on different descriptors. Three floors of the building are instrumented; the soil and building are characterized using an artificial source (impact hammer). At least 19 runs of different indicators are analyzed and a statistical evaluation of these parameters is performed.