Proceedings of 20 th International Congress on Acoustics, ICA 2010 23-27 August 2010, Sydney, Australia ICA 2010 1 A Review of Prediction Methods for Ground-Borne Noise due to Construction Activities Dave Davis (1) (1) Parsons Brinckerhoff, Brisbane, Australia PACS: 43.40.RJ RADIATION FROM VIBRATING STRUCTURES INTO FLUID MEDIA ABSTRACT The generation of ground-borne noise inside receiver buildings due to nearby construction works can cause signifi- cant community impact and impose difficult constraints on construction activities. Several methods exist to predict ground vibration from permanent operational sources; however the suitability of some of these methods to predict ground-borne noise from construction activities are not well known and have not yet been thoroughly tested. This pa- per presents an overview of some of the various methods available to estimate ground-borne noise levels from con- struction activities and discusses the advantages and limitations of each. INTRODUCTION The generation of ground-borne noise inside receiver build- ings due to nearby construction works can cause significant community impact and therefore needs to be assessed prior to construction commencing. It would be advantageous to be able to reliably and efficiently predict the ground-borne noise impact resulting from pro- posed construction activities, including the effect of all rele- vant parameters and variables, since it would allow investiga- tion of any opportunities that may exist to implement mitiga- tion treatments. However, the prediction of vibration propagation through soil is a complex task, made difficult by the inhomogeneity of the vibration propagation medium (ie. soil and/or rock). Several methods have evolved to predict ground vibration from vari- ous operational sources; however their suitability for predic- tion of ground-borne noise from construction activities is not well known and has not yet been thoroughly tested. For instance, the generation and propagation of vibration and ground-borne noise has been extensively studied for the par- ticular case of underground rail movements, and many well- established techniques now exist for this task. However the literature is comparatively sparsely populated in regard to discussion of the suitability of those same prediction method- ologies for a slightly different purpose: namely the construc- tion of underground structures. Another important consideration is the relative simplicity, speed and accuracy of the various methods when used for predicting the impact from construction activities. Since con- struction activities are temporary and of relatively short dura- tion, the aims of the modelling exercise will likely have dif- ferent goals and priorities in comparison to an investigation for a permanent vibration source, and hence it may be appro- priate and/or desirable to sacrifice modelling accuracy with ease of constructing, running and modifying models. BASIC THEORY The prediction of ground-borne noise levels from construc- tion activities requires knowledge of the input vibration forces from the vibration source(s) into the cutting face, knowledge of the vibration transmissibility of the surround- ing medium, and knowledge of the receiver building’s vibro- acoustic response. The conversion of this vibration energy into sound pressure within the receiver building depends upon the coupling of the soil & the building’s foundations, the structure’s response including floor-to-floor attenuation and amplification due to resonance, the radiation efficiencies of the internal structural elements, and the room’s acoustical properties. Beginning with a known input vibration spectrum at the cut- ting face, it is possible to predict the resultant ground-borne noise levels within a receiver building using either semi- analytical and/or empirical techniques, or by numerical mod- elling. The inherent variability and inhomogeneity of the soil and rock propagation medium means that site-specific geological information must be accounted for somehow in whatever prediction methodology is to be used. Ground vibration propagates through the soil or rock as waves, so that the amplitude generally decreases with dis- tance from the source. There are several different types of ground vibration waves, which propagate through different mechanisms and consequently exhibit different behaviours. The types of waves that are usually the most important are: x Compressional waves [primary (‘P’)-waves], x Shear waves [secondary (‘S’)-waves], and x Rayleigh waves [‘R’-waves]