OPAC CONSULTING ENGINEERS - Key Persons
The arch bases serve as piers to support the steel arch ribs, the steel roadway girder, and the concrete viaducts. They are reinforced and post tensioned concrete slab and beam structures. The curves of the arch base edges are joined by faces that are surfaces of single curvature. Therefore, they can be formed readily using conventional formwork. They are post-tensioned vertically and transversely to facilitate the transfer of arch rib thrust forces to the foundations.
The arch tables are the platforms between the arch ribs within the arch bases. They are designed to serve the following functions:
Provide a transverse tension tie between arch ribs at the deck level.
Collect thrust from the arch ribs and deliver it to the longitudinal arch tie.
Provide an anchorage for the longitudinal deck tie.
Provide an anchorage for the longitudinal approach span tendons.
Provide a 20-meter section of the deck between the main span and approaches.
The arch tables include a 10.5-meter wide transverse box girder integral with a 20-meter long deck segment and 3-meter thick horizontal diaphragms within the concrete arch ribs.
Job Titles:
- Extension - Design and Construction Support
Mr. Drouillard has extensive experience in conceptual and final design, field and office engineering support of construction projects, design-build projects, structural rehabilitation, and engineering management. He has been in engineering practice since 1983.
Francis Drouillard has 28 years of experience in the design, project management, and construction support engineering of long-span light rail and highway bridges. Mr. Drouillard has designed a variety of bridge types that include concrete box girders, steel arches, composite steel girders, cast-in-place segmental balanced-cantilever box girders and cable-supported bridges. He has also provided construction support engineering and field supervision on various complex bridge projects.
Gerald Desmond Bridge Replacement - Independent Check of the Cable-Stayed Bridge
Job Titles:
- Colorado River Bridge - Construction Engineering
Kwong Cheng, current OPAC principal, served as Project Manager and Lead Engineer while at TYLI, and directed a team of engineers to perform the design and to prepare contract documents. He established the segmental erection sequence for the bridge superstructure, including segment-by-segment erection of form travelers, placement of concrete, stressing of tendons, and moving of formwork. Based on this sequence, he developed a time-dependent erection sequence computer model in the SFRAME/S3D computer program, to track each construction stage and time dependent behavior through expected service life. This modeling provided camber charts and tendon stressing specifications for use by the contractor. He also provided training to the owner's site engineer and met with the contractor to resolve construction issues throughout the construction phase.
Mr. Cheng started OPAC in 1992 and led the firm until his retirement in 2021. He provided expertise in bridge design, construction engineering, and engineering management. He has been in engineering practice since 1978 and has been responsible for bridge design or construction engineering of projects on three continents.
Kwong Cheng has 43 years of experience in structural engineering design, management, and constructability analysis of bridges and transit structures. Mr. Cheng served as Project Manager and Lead Engineer for numerous bridge projects in Asia and America, and has in-depth experience in the construction engineering of long span structures.
Lewiston, Idaho and Clarkston, Washington. Design completed 1979
Job Titles:
- Principal
- Professional Services Inquiry
Mr. Etchepare provides technical expertise in the design and management of complex bridge and utility structures. He has been in engineering practice since 2006.
Matthew Etchepare has 16 years of experience in the analysis, design, project management, and construction support engineering of complex bridges and transportation and utility structures.
Mr. Etchepare has designed a variety of bridge types that include concrete box girders, steel arches, composite steel girder and cable-supported bridges. He has also provided erection engineering and construction support on various complex bridge projects.
A 300 m span steel arch bridge across the Yong River. The arch ribs are steel box sections and the deck consists of a steel box girder with an orthotropic deck.
Nanning City, China. Construction completed 2009
Smith River Bridge (George Tryon Bridge) Replacement - Erection Engineering
Ms. Chang leads the firm and provides expertise in bridge design, construction support engineering, and project management of rail transit structures, complex urban freeway interchanges, river crossings, and pedestrian structures. She has been in engineering practice since 1982.
Vivian Chang has 39 years of experience in the design, project management and construction support of highway and transit bridges. Ms. Chang has designed a variety of bridge and transit structures that include prestressed concrete box girders, prestressed segmental concrete box girders, steel arch, and cable supported structures. She has provided project management and construction support engineering on various complex bridge and transit projects.