Projects

TSI performed engineering and construction services for this flood emergency project for the State of California. Chowchilla Canal Bypass structure is located in Madera County, California. This canal structure is comprised of four (4) bays; each bay 20 feet wide, having a radial gate (20 feet wide and 17’-2” feet high) with radius of 18 feet, operated by electric motor. The canal structure was built in 1965. Existing gate is fabricated by strut arms (W8x35) with bracing systems (W8x20), and ¼” skin plates on WT4x6.5 radial vertical rib web.

Cause of Modification: Radial gate starts vibrating at water column three (3) feet and above due to hydraulic pressures on upstream sides, which can fail during flood season.

Modifications Implemented: To stabilize existing structure, retrofitting was proposed by adding braces of HSS 2x2 x¼ on each radial gate. To achieve this target, TSI prepared preconstruction submittals including shop drawings, test existing paint by a qualified personnel , remove existing paint and epoxy coatings over spotted area of gates to weld braces. This was followed by welding of braces, channel (MC 7x22.7), banding bars, and installing caps to structurally enhance the strength of existing gates. The modified gates were treated with high solid epoxy coatings (three coats to achieve a total of 20.0-24.0 mils thickness), and were further applied with semi-gloss aliphatic polyurethane topcoat. Finally the stop logs and sandbags used to form water barriers were removed by deploying an overhead crane.

Apart from other government construction projects in hand, TSI completed this project before time to meet the deadline to release emergency flood water. Following were the main challenges which TSI engineers and construction team met successfully and to the entire satisfaction of the client:-

• Completed the project two weeks early to meet the requirement of early release of emergency floodwater in the river.
• A functional riparian habitat for three endangered species that had been inadvertently over-cleared, TSI designed a restoration and enhancement program to restore the habitat.
• Design and provided temporary stop logs to eliminate sandbags dikes to deal with the emergency situation. This provision was more efficient and substantially cost effective.
• Design and built temporary platforms above expected level of water flow in each bay to generate reasonable work areas for the free movement of workforce to ensure quality performance.
• Used heaters and other drying devices specially at nights to dry epoxy coatings in humid environment to achieve the target completion date.
• Checked the functions of hydraulic gates for trouble- free operation.