KCC

Princeton University Dam

Princeton, NJ

Phase I-IV structural repairs to the university's historically significant Carnegie Lake Dam

Background

KCC submitted the winning proposal to Princeton University Facilities Organization for this fixed-price contract to perform the Phase I structural repairs to the historically significant Carnegie Lake Dam.

This included repair work to the west abutment and extended 190 feet along the dam into the Millstone River. The 690-foot long concrete dam was built across the Millstone River in 1906 with a generous donation from Andrew Carnegie. Lake Carnegie was formed by the dam and has become a coveted feature to the local community as well as home to the Princeton University rowing team, which uses the lake for crew racing competitions.

Project Highlights

  • An upstream coffer dam was designed and constructed by KCC using sand-filled super bags along with steel sheet piles to hold back 9 feet of water and create control for dry working conditions
  • All work in the water and on the dam was performed in compliance with NJDEP and NJSHPO permits that were issued for the project
  • Typical section through the concrete dam is approximately 5-foot thick and 12-foot high with 4-foot-thick curved buttresses placed roughly 28 feet on center on the downstream side
  • After assessing repairs in earlier years with a shotcrete layer, the design team required the entire 2-inch to 3-inch shotcrete layer to be removed from the dam in order to expose the underlying conditions after a century of wear
  • There were six different types of repair strategies prepared by the design team and after further removal and exposure of more damage than originally expected, KCC and the design team adapted to such changes and developed new solutions to remedy without work interruption
  • Structural Repairs included repair work to the West & East Abutments and extended 690 feet along the dam and across the Millstone River.
  • To control the water and create dry working conditions, an upstream cofferdam was designed and constructed by KCC with steel sheet piles to hold back 9 feet of water. Sand-filled Superbagswere used for the downstream cofferdam.
  • All work in the water and on the dam had to be performed in compliance with permits issued by the NJDEP and NJSHPO.
  • The typical section through the concrete dam is approximately 5’ thick and 12’ high, with 4’ thick, curved buttresses placed roughly 28 feet on center on the downstream side.
  • The repair work first started with the complete removal of the 2” to 3” thick layer of shotcrete. The design team required the entire shotcrete layer to be removed from the dam in order to expose the underlying conditions.
  • The design team had prepared a menu of six different types of repair strategies that were to be implemented based on assessments made of the underlying conditions. As the shotcrete layer was removed by the construction crew, the design team determined that some areas of the dam were more damaged than originally believed.
  • Some new solutions were developed by the design team for these specific areas. KCC’s experienced construction team was able to adapt to these changing conditions and implement the new remedies without any interruptions to the work.