Location

New York, New York

Date

16 Apr 2004, 8:00am - 9:30am

Abstract

There are numerous abandoned iron mines that dot the landscape within the Highlands of Morris and Passaic Counties in northeastern New Jersey. In recent years, as development has continued to expand in rural communities in New Jersey, these abandoned mines have had an impact on numerous construction projects within the state. The Woodhull Iron Mine was initially developed in the 1860’s, but production was insignificant. All mining activity had ceased by the late 1880’s. The mine workings consisted of a series of northeast-southwest trending magnetite-enriched zones of some 3 to 5 feet in thickness, dipping to the southeast between 55 and 65 degrees. The workings extended northeasterly from the vicinity of the present-day Chester-Gladstone Rd up to and across Rte. 206. Over time, the headwall of the workings partially collapsed, leaving behind obscure, overgrown shallow depressions at the surface. Development at the site of the abandoned Woodhull Mine began in the late 1990’s with construction of an age-restricted community of high-end town houses. Early reconnaissance efforts to locate the mine on site were unsuccessful. It was not until construction and site development was well underway that subsurface voids were encountered during placement of underground utilities. The project was temporarily halted in that part of the site until agreement could be reached between township officials, the Bureau of Mine Safety and the developer as to how best to proceed. A Mine Closure Plan was developed, wherein specific closure criteria were outlined. The mine workings were grouted with a highmobility cementitious grout tremied into the mine voids through angle borings drilled along the dipping plane of the mine. Approximately 1,800 yds3 of grout were placed in the mine, effectively sealing both the voids of the mine and the partially collapsed hanging wall rocks above them. With the approval of both township officials and the NJ Bureau of Mine Safety, project development continued.

Department(s)

Civil, Architectural and Environmental Engineering

Meeting Name

5th Conference of the International Conference on Case Histories in Geotechnical Engineering

Publisher

University of Missouri--Rolla

Document Version

Final Version

Rights

© 2004 University of Missouri--Rolla, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 13th, 12:00 AM Apr 17th, 12:00 AM

Closure of the Woodhull Mine Chester, New Jersey

New York, New York

There are numerous abandoned iron mines that dot the landscape within the Highlands of Morris and Passaic Counties in northeastern New Jersey. In recent years, as development has continued to expand in rural communities in New Jersey, these abandoned mines have had an impact on numerous construction projects within the state. The Woodhull Iron Mine was initially developed in the 1860’s, but production was insignificant. All mining activity had ceased by the late 1880’s. The mine workings consisted of a series of northeast-southwest trending magnetite-enriched zones of some 3 to 5 feet in thickness, dipping to the southeast between 55 and 65 degrees. The workings extended northeasterly from the vicinity of the present-day Chester-Gladstone Rd up to and across Rte. 206. Over time, the headwall of the workings partially collapsed, leaving behind obscure, overgrown shallow depressions at the surface. Development at the site of the abandoned Woodhull Mine began in the late 1990’s with construction of an age-restricted community of high-end town houses. Early reconnaissance efforts to locate the mine on site were unsuccessful. It was not until construction and site development was well underway that subsurface voids were encountered during placement of underground utilities. The project was temporarily halted in that part of the site until agreement could be reached between township officials, the Bureau of Mine Safety and the developer as to how best to proceed. A Mine Closure Plan was developed, wherein specific closure criteria were outlined. The mine workings were grouted with a highmobility cementitious grout tremied into the mine voids through angle borings drilled along the dipping plane of the mine. Approximately 1,800 yds3 of grout were placed in the mine, effectively sealing both the voids of the mine and the partially collapsed hanging wall rocks above them. With the approval of both township officials and the NJ Bureau of Mine Safety, project development continued.