NAVFAC Drydock Emergency Repairs: Fast, Flawless Delivery via Innovative and Fully Integrated Design

Abstract: In January of 2023, the U.S. Navy called KAJV (Kiewit-Alberici Joint Venture) to respond to an emergency request to provide a seismic retrofit for a series of drydocks at their Naval Bases on the Kitsap Peninsula in Washington. The drydocks were vulnerable to collapse under the Level 2 Design Earthquake (2,475 years) event. KAJV was tasked with the mission to complete the work in four months.
KAJV quickly assembled a design team led by KIE (Kiewit Infrastructure Engineering) engineers and within a week, preliminary designs had been completed for two of the drydocks, materials were procured, equipment was mobilized, and in four months construction was completed.
The design concept selected consisted of a pattern of ground anchors drilled through the drydock walls into underlying very dense, glacially overridden soils. The selected anchor solution reduces bending and shear demands on the drydock walls and the connection to the base slabs. The use of ground anchors takes full advantage of the as-built existing structural capacity, while enhancing the global seismic resistance of the drydock, thereby eliminating the need to demolish and reconstruct a drydock to modern seismic detailing requirements. Structural design was completed using streamlined design methods based on first principles and rational assumptions. Structural detailing was tailored to accommodate construction preferred methods and available materials.
Detailed plans were developed, and analyses completed to address earth pressures on the walls (including seismic loading), liquefaction, anchor testing, and corrosion of ground anchor elements. While the design was in progress, the team not only refined and verified the design through testing, it made sure to do no harm to the drydocks in the process. As one can imagine, as drydocks are complex machines meant to support the maintenance of war machines, there are countless obstacles to avoid or deal with; crane rail piles, utilities, artesian wells, sheet piling, piezometers, to name a few. The do no harm mission, was a constant challenge requiring many a summit to bring in experts, write white papers to build consensus and to do advanced structural analysis. From advanced analysis of partially penetrated piling to grout infiltration and how to prevent it, this paper will dive into the details of how the team solved these issues, while still accomplishing the mission in record time. The seismic performance of the retrofitted and un-retrofitted drydocks was assessed using Time-History Soil-Structure interaction analyses for a Level 2 Design Earthquake event. The findings of this seismic performance evaluation were that prior to retrofitting the drydocks, the drydocks showed a very high likelihood of collapse during Level 2 Design Earthquake ground motions. After the seismic retrofits, it was found that the drydocks had substantially increased their resistance to seismic demands and that the retrofitted locations will survive the Level 2 Design Earthquake level ground motions.
Within four months, the KAJV team installed 695 tieback ground anchors ranging from 76ft to 164ft in length, providing substantially improved seismic resilience to three critically important drydocks, accomplishing the mission.

How does this project / topic contribute to the advancement of the industry and profession?: The design work performed on this project is a testament to what a fully integrated owner, engineering and construction team can achieve in an emergency situation. The design/construction processes and steps used in traditional design-build projects were accelerated by implementing rapid decision making, and carefully tailoring design to the available construction means and methods and materials. Additionally, the fully integrated nature of the project team led to rapid and cost effective decisions made in real time as a myriad of challenges were faced during the complex retrofit of a sophisticated machine where do no harm requirements were paramount to success.

Does the project / topic implement new and innovative techniques, materials, technologies, and delivery methods?: Yes, multiple unique challenges were faced which required innovative and novel solutions. At the base level, drilling through more than 12 feet of concrete (the drydock walls), sand, sheet pile coffercells, sand and gravel, then glacial till into artesian conditions required innovation and significant collaboration. Durability was another innovation required due to the emergency nature of the project, field constructed double corrosion protected equivalent anchors were fabricated. Dewatering, grout intrusion, durability, drilling operations and field testing all required novel white papers to be drafted by a team of experts.

What was the most challenging aspect of your project / topic and how did you handle it to ensure success?: To meet the aggressive schedule, we had to quickly understand the essence of the structural problem we were facing. This was achieved by relying largely on first principles of structural engineering. The development of a series of design tools was needed to the address varying site conditions, and provide the input that construction needed to continue to advance their design. Additionally the team faced the challenges of artesian conditions, field constructed double corrosion anchors, extremely difficult drilling,proving out anchor capacity, grout intrusion and anchor head protection. The team solved these problems on an aggressive schedule with advanced modelling and analysis.

Who is the target audience for this paper?: This project cut through so many processes and procedures that tend to bog a project down without adding value. So, anyone, who wants to learn in and ponder novel ideas on how to make a project move effectively from notice to proceed to completion will benefit from listening in. All members of the ports and harbors development industry. This includes engineers and engineering professionals (marine, structural, geotechnical, environmental), terminal operators, owners (government agencies and private industry), consultants, contractors, stakeholders, and students.