Unreinforced concrete pipes basically can fail in two modes: beam failure and ring failure. According to the existing test data, the nom· inal stress at beam failure is much less than that at ring failure. Fur· thermore, the nominal stress for either failure mode decreases as the pipe diameter or thickness increases. These size effects can be de· scribed in a unified manner by means of the rece...

The pathways, through which water quality in the distribution network can be compromised, may be classified into five categories: intrusion of contaminants into the distribution system (e.g., through cross connection), regrowth of bacteria in pipes and distribution storage tanks, water treatment breakthrough, leaching of chemicals or corrosion products from system components (pipes, tanks, line...

For older water pipeline materials such as cast iron and asbestos cement, future pipe failure rates can be extrapolated from large volumes of existing historical failure data held by water utilities. However, for newer pipeline materials such as polyvinyl chloride (PVC), only limited failure data exists and confident forecasts of future pipe failures cannot be made from historical data alone. T...

Welding quality control is an important parameter for safe operation of oil and gas pipes, especially for high-strength steel pipes. Size control of welding defect is a bottleneck problem for current pipe construction. As a key part of construction procedure for butt-welding of pipes, pore defects in girth weld is difficult to ignore. A three-dimensional non-linear finite element numerical mode...

Water distribution networks (WDNs) represent a class of critical infrastructure networks. When a disaster occurs, component failures in a WDN may trigger system failures that result in larger-scale reactions. The aim of the paper is to evaluate the evolution of system reliability and failure propagation time for a WDN experiencing cascading failures, and find the critical pipes which may reduce...

This paper considers the problem of internally inspecting underground pipes, such as sewers, in order to identify and locate major structural defects or damage to the pipes, and to identify potential defects which may lead to failure. It considers three aspects of the pipe inspection task; namely, the extraction of geometric primitives from the pipe image sequences, the tracking of these primit...

Vibration fatigue failure is a critical problem of hydraulic pipes under severe working conditions. Strain modal testing of small and light pipes is a good option for dynamic characteristic evaluation, structural health monitoring and damage identification. Unique features such as small size, light weight, and high multiplexing capability enable Fibre Bragg Grating (FBG) sensors to measure stru...

water is the most essential component for sustaining lives of humans and other living creatures. supplying potable water with adequate residual pressure is a fundamental responsibility of city administration, which they do during normal conditions. but sometimes, abnormal conditions are formed resulting pressure deficient conditions during the daily operations of water distribution networks. th...