On the effects of soil properties on leak noise propagation in plastic water distribution pipes

Abstract

In many countries, leaks are located in water distribution pipes by using the cross-correlation of pipe vibration measured either side of a suspected leak. However, in modern plastic pipes this can be problematic due to strong coupling between the water, the pipe and the soil, affecting the propagation of leak noise within the pipe. This paper concerns an analytical, numerical and experimental investigation into the way in which soil properties influence leak noise propagation in buried plastic water pipes. The analytical model allows a detailed investigation into the physical effects of the soil on leak noise (wave) propagation in the pipe, in particular on the wave speed and wave attenuation. Results highlight that, in addition to the pipe hoop stiffness, the shear stiffness of the soil can have a significant effect on the wave speed in the pipe. Experimental measurements were conducted at two different sites-one in the UK and the other in Brazil. In the UK system, both dilatational and shear waves in the soil propagate away from the pipe, resulting in large wave attenuation in the pipe. However, in the Brazil system, only shear waves propagate resulting in smaller wave attenuation in the pipe.

Importancia de la selección de banda de frecuencia para estimación del retraso de tiempo en la detección de fugas en tuberias plásticas de agua enterradas

“…The wave speed calculated is 497 m/s for data A and 377 m/s for data B. Compared with the theoretical wave speed of 540 m/s given in ref [8]…”

A Comprehensive Review of Acoustic Methods for Locating Underground Pipelines

“…In this section, based on the features of above-listed locating techniques, as well as the analysis and decision tree in [11,150], a flow chart for selecting the preferred pipe localization methods is illustrated in Figure 21. Furthermore, accurate evaluation in-situ acoustic properties of soils, especially wave speed, plays a significant role in the seismic wave method [101,102] and pipe leakage detection [143], as wave speed is directly related to the interpretation of measurement results. Therefore, many studies have been conducted on measurement of soil properties, which can be found in [144][145][146][147][148].…”

Estimation of the bulk and shear moduli of soil surrounding a plastic water pipe using measurements of the predominantly fluid wave in the pipe

“…The effects of the soil properties on wave propagation in a buried pipe, such as that shown in Fig. 2, have been investigated by Muggleton et al [18], Muggleton and Yan [23], Gao et al [24,25] and Brennan et al [26]. Here, the most complete model of the buried water pipe system, which is described in [24], is used in the determination of the soil properties.…”

“…It is known that the soil properties have a profound effect on both the speed of the leak noise propagation along the pipe (wave speed), and the attenuation of this wave [22][23][24][25][26]. The works discussed hitherto did not model the soil effectively, as it was treated as a fluid supporting elastic waves in the soil.…”

“…Leak noise correlators are often used to detect and locate leaks by sensing acoustic pressure in the pipe or pipe vibration [22,26], and the wave speed has a profound effect on the accuracy with which the leak can be located using these devices. Furthemore, the wave attenuation governs the maximum distance from the leak that each of the sensors can be positioned for the correlator to work effectively [23][24][25][26].…”