The generalized Hough transformmethod is applied to the measurement of the diameters of buried cylindrical pipes by Ground Penetration Radar (GPR). 600 MHz radar scans across long pipes, buried in one metre or so of soil, show complex reflection patterns consisting of a series of inverted hyperbolic arcs. The time of flight t(y) as the radar probe is scanned along an axis, y, perpendicular to t...

An algorithm for online distance computation based on images taken in a sewer by a robot-inspector is presented. Modern concrete sewers are made of standard cylindrical pipes separated by manhole junction areas. Circular structures typically originate at the pipe ends and entrances as well as at the joints of the pipe sections. These structures provide regular marks on the sewer images and can ...

In water distribution systems containing PVC pipe manufactured in the ‘‘early era’’ ~prior to 1977!, vinyl chloride can leach into drinking water resulting in vinyl chloride concentrations exceeding the 2 mg•L maximum contaminant level. Field testing of dead-end segments of water distribution systems consisting of early-era PVC pipe was conducted to examine their initial intrapipe vinyl chlorid...

Buried pipeline systems are commonly used to transport water, sewage, oil, natural gas and other materials. In the conterminous United States, there are about 77,109 km (47,924 miles) of crude oil pipelines, 85,461 km (53,114 miles) of refined oil pipelines and 67,898 km (42,199 miles) of natural gas pipelines (FEMA, 1991). The total length of water and sewage pipelines is not readily available...

An investigation was carried out to establish the physical, mechanical and chemical characteristics of a non-standard (unprocessed) pulverised fuel ash (PFA) and waste tyres from a former landfill site at the Power Station Hill near Church Village, South Wales, United Kingdom. Investigations are on-going to establish the suitability of the fly ash and/or tyres in road construction (embankment a...

in this paper we investigate the mechanism of internal erosion caused in the right abutment of the shahghasem dam’s spillway. shahghasem dam is an earthen dam located in yasouj, in southwest of iran. a significant hole and pipe have been observed in the corner of the right abutment from upstream view. the foundation is marlstone, which has low cohesion and susceptible for internal erosion and p...