CITY OF ST. LOUIS WATER DIVISION, CONDUIT REHABILITATION
Jason Consultants worked as a specialist consultant with Sverdrup Civil Inc. The project consisted of the rehabilitation of approximately 16.5 miles of 60” diameter steel water conduit between Howard Bend Water Treatment Works and the city limits.
Jason Consultants’ role was to provide specialist rehabilitation expertise to the lead consultant. The first stage of the project was the inspection and condition assessment of the existing conduit and to establish the evaluation criteria. The second stage was to evaluate the rehabilitation methods available and to prepare designs and specifications for the most appropriate methods in order to provide the client with a solution that combines technical integrity with cost-effectiveness.
Client: Sverdrup Civil Inc.
BASSA PUMPING MAIN, TEL AVIV, ISRAEL
Jason Consultants was appointed by the client to investigate failure of a 1250mm diameter asbestos cement force main in an urban area of Tel Aviv. Following the investigation we developed rehabilitation options for 7000 metres of mains, wrote Specifications and contract documents, evaluated bids and assisted the client and Contractor in implementing the chosen solution to meet the strict Specification requirements.
Client: Dan Region Association of Towns
BALTIMORE INSPECTION PROGRAM FOR WATER MAINS
In May, 2005 the City of Baltimore awarded a contract to the joint venture PHRA/Jason Consultants to develop an inventory of Baltimore’s 210 miles of water transmission mains, 36-inch diameter and larger. In addition, the joint venture is to establish a priority rating system for identifying those reaches that require inspection and/or monitoring, and to develop and carryout a pilot inspection and assessment program for those reaches at the highest risk.
The majority of the large diameter water transmission mains are made of prestressed concrete cylinder pipe (PCCP). The City had previously experienced three failures in one line, the 54” Southwest Transmission Main, so this line was targeted early for inspection. However, it was not possible to completely isolate the entire 16,600 feet of 54” pipe so only approximately 15,000 feet has been inspected. In addition, a 22,000 ft branch of 36-inch diameter PCCP line serving Howard County was also inspected and assessed during the outage. The slope exceeded 47 degrees in some parts of this 36-inch main making it very challenging to internally transverse.
Pure Technologies carried out a remote field eddy current (RFEC) survey identifying possible wire breaks in both lines. In addition, the joint venture arranged for Openaka to carry out an internal inspection and sounding (54” only) of both lines.
A 3,000 foot section of the 54” Southwest Transmission Main was found to be in an advanced state of extreme distress. Nearly 46% of the pipes in this section had either internal longitudinal cracks, many with hollow sounding areas, and/or a significant number of wire breaks. It was decided that this main could not be returned to service and summer water restrictions have gone into effect. Emergency plans are being drawn up to replace approximately 4,300 feet of the main. In addition, there were 13 other pipes outside the severely distressed area, but still in the 16,600 ft line, which also showed a high level of distress. These pipes, with limited external access, will be structural restored using an internal lamination of uni-directional carbon fiber fabric and epoxy resin. The composite materials are listed against NSF No. 61 for use in potable water.
Client: City of Baltimore
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