Leakage is undesirable in water distribution networks, as leaky pipes are financially costly both to water utilities and consumers. The ability to detect, locate, and quantify leaks can significantly improve the service delivered. Optical fibre sensors (OFS) have previously demonstrated their capabilities in performing real-time and continuous monitoring of pipe strength leak detection. However, the challenge remains due to the high labour cost and time-consuming process for the installation of optical fibre sensors to existing buried pipelines. The aim of this paper is to evaluate the feasibility of a submersible optical fibre-based pressure sensor that can be deployed without rigid bonding to the pipeline. This paper presents a set of experiments conducted using the proposed sensing strategy for leak detection. The calibrated optical fibre device was used to monitor the internal water pressure in a pipe with simultaneous verification from a pressure gauge. Two different pressure-based leak detection methods were explored. These leak detection methods were based on hydrostatic and pressure transient responses of the optical fibre pressure sensor. Experimental results aided in evaluating the functionality, reliability, and robustness of the submersible optical fibre pressure sensor.

Water pipe infrastructure, especially cast iron and asbestos cement, are close to or past their recommended service life. Rehabilitation of this existing water pipe infrastructure is critical to reduce replacement costs and water loss. Cured-in-place pipe (CIPP) liners are one method of pipe rehabilitation, and long-term properties are integral in the design of CIPP liners for water pipes. Limited studies have focused on testing and reporting of long-term properties, which are essential for the service life design of CIPP products. This paper aims to investigate the long-term properties of a CIPP liner under service conditions (static pressure and pressure transients). Three types of tests, namely, creep, creep rupture, and fatigue tests, were examined. Results indicated that the creep retention factor (0.18–0.27) at 50 years does not correspond to the long-term rupture tensile strength reduction factor (0.7) at 50 years. Long-term creep degradation curves show that, when subjecting the liner to constant stress, the short-term strength of the liner remains close to the initial tensile strength. The long-term strength reduction factor due to fatigue (0.73 at 100 million cycles) suggests this CIPP material is less influenced by pressure fatigue cycles. Therefore, the creep retention factor is not a true estimate of rupture strength or fatigue strength reduction.

It was reported that the leak-before-break (LBB) concept has potential merit for use as a tool for large-diameter pipe failure prevention in the water industry. For this purpose, a detailed understanding of pipe failure mechanisms and the LBB time window between leak initiation and failure is essential. Controlled laboratory experiments can provide valuable information to address this research question. Therefore, this paper presents a new fully automated laboratory test facility that was developed to investigate the time window between leak initiation and final burst (during fatigue crack growth with variable internal loading including pressure transients) in large-diameter cast iron water pipe. The new setup will be used to validate the application of LBB and to quantify the LBB time window for proactive pipe monitoring for failure prevention. A full-scale pipe test conducted using the new test facility is presented to demonstrate the capability of the new test facility.

This study reports the findings from a round robin across 14 geotechnical engineering groups across several Australian and Indian universities, that was carried out to study the reproducibility and variability associated with the measurement of soil shrinkage curve (SSC). A standard operating procedure was developed for determining SSC of soils, that was provided to all the participating groups, along with two clay samples and shrinkage moulds. Variations were observed in the liquid limit and specific gravity of the two samples reported by the participating groups, that were sensitive to the testing method followed. A procedure was devised and applied to correct the SSCs reported by some of the groups, due to deviations from the expected soil behaviour. The suggested correction procedure addressed the uncertainties in the measurement of bulk volume and specific gravity of the samples. The mean and the median shrinkage limit obtained for both the samples, from the corrected SSCs, were close to each other. Barring a couple of exceptions, symmetric frequency distributions were observed for all the SSC fitting parameters (minimum void ratio, shrinkage limit, curvature of SSC) with the spread limited to a maximum of ± 2 times the standard deviation from the respective mean values.