Negotiating and Executing High-Risk, Contractor-Proposed 30-Inch Horizontal Direction Drill along Colonial-Era, Historical Structure in Urban, Downtown Corridor

摘要

During force main construction in Downtown Norfolk, Virginia, the general contractor wanted to avoid an especially challenging segment of open-cut installation adjacent to a high-end shopping mall. After considering and excluding several ideas, a 1,000-LF 30-in horizontal directional drill (HDD) was proposed at no cost to the project. Although this project was a typical design-bid-build, the proposal to perform a HDD in the middle of construction initiated a pseudo design-build effort. The complicated nature of Downtown Norfolk's subsurface required historical reviews of land reclamation and advanced geotechnical considerations to address potential risks. Primarily was the proposed HDD path location alongside the oldest structure in Norfolk: St. Paul's colonial-era historic church constructed in the 1730s. This paper explains the vetting strategies of the expeditious design and proactive observation measures implemented to reduce risk. It also details how the contractor, engineer, and owner collaboratively negotiated this major change in work and garnered buy-in from City officials and local stakeholders. In addition, the financial and contractual terms of the change order are presented to show how all parties came together for the mutual benefit of the project and implemented this change at no cost to the project.