Talbert Channel and Huntington Beach Channel Sheet Pile Repair Project

Abstract: The Orange County Flood Control District (OCFCD) had engaged Reyes Construction + GHD Inc. Design-Build team to repair the existing corroded steel sheet pile wall segments of the Huntington Beach Channel and the Talbert Channel (OCFCFD Facilities D01 and D02, respectively). The repair solution had to be designed and constructed in a condensed time frame before the existing FEMA accreditation expired and affected the flood insurance coverage of over 100,000 residents in the region. Design services included geotechnical investigations to determine the global levee stability for segments being repaired. Hydraulic analyses were performed to support the accreditation process.

The repair included installation of 16,955 linear feet of AZ44 / AZ52 steel sheet pile walls directly behind the existing sheet piles, reducing the environmental impacts from construction within the channels. The flood channels are bounded by residential neighborhood on both sides which limited the access for heavy construction equipment needed for such work. The use of Giken machine to install the sheet piles helped minimize the footprint of the construction equipment, reduced the noise and vibration impacts during construction. An existing pedestrian bridge connected the residential neighborhood to the school across the channel had to be moved. Due to limited staging area, the bridge was lifted off the abutment using two cranes in tandem, and stored on temporary supports a short distance downstream and allowed the construction to continue around the bridge.

As the construction phase commenced in January 2022, the COVID-19 crisis posed several challenges for the project. There was a four-month delay in project commencement due to material availability, increase in material cost, and scarcity in transportation caused by the pandemic. The project design team navigated several challenges by extensive planning, coordination, and collaboration with the stakeholders. The project was completed in July 2023.

How does this project / topic contribute to the advancement of the industry and profession?: The project showcases a unique solution to repair and replace existing sheet piles in areas where waterside construction is not possible for several reasons – schedule, environmental impacts, permitting constraints etc. The project has demonstrated that sheet piles can be installed on the backside of existing deteriorating sheets with limited access and impacts to landside area. The solution can be extended to other facilities where suitable and expedite repair and rehabilitation of infrastructure.

Does the project / topic implement new and innovative techniques, materials, technologies, and delivery methods?: The project addresses a widespread issue in the industry to repair and replace bulkhead sheet pile walls while minimizing impact on operations. The solution implemented on the project was unique where new sheets are installed directly behind existing deteriorating sheets within a few inches. The project also used press-in method of installation that prevented noise and vibration related damages to neighboring structures.

What was the most challenging aspect of your project / topic and how did you handle it to ensure success?: Project schedule was the most challenging aspect of the project. Permits for typical repairs on the waterside would have extended the schedule by several months. However, the creative solution to install new sheets on the landside avoided the in-water impacts and allowed for expedited permit review. Another challenge was to install the new sheets under an existing timber pedestrian bridge. The bridge had to be temporarily moved with limited access for a large crane. The bridge was eventually lifted and moved using two small cranes, working in sync.

Who is the target audience for this paper?: Owners, Engineers