Location

New York, New York

Date

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

Abstract

This paper presents three (3) case histories associated with the construction of the Support Of Excavation (SOE) system for parts of the new underground (Phase II) Silver line subway system in downtown Boston. The first case study addresses the design and construction of the cantilevered sheet piles at the Fort Point Channel. The design and construction of a drift tunnel below the Russia Wharf complex is presented as the second case history. Finally, the third case study presents the analysis and design of the support of excavation system for the construction activities at the West Cofferdam. To allow the construction of the perimeter walls for an underground garage using the bentonite slurry technique, a 25 to 30 ft thick flowable fill material was placed at the west shore of the Fort Point Channel. The placed flowable fill was retained using an HZ pile system that was constructed to cantilever 25 to 30 feet. The performance of the HZ piles was within design expectations. The second case history addresses the construction of a drift tunnel located adjacent to the exterior wall of an existing tenant occupied historic building. This was undertaken to allow the permanent underpinning of said exterior wall. The third case history addresses the design and construction of a cofferdam for the construction of a cast-in-place transition between the immersed tube tunnel sections under the Fort Point Channel and the NATM tunnel under the Russia Wharf complex. A Value Engineering Cost Proposal (VECP) was proposed and implemented to eliminate 90 feet of NATM tunnel by extending the cofferdam and to reduce the number of bracing levels from five to three. The underground tunnel and the surrounding structures were analyzed using three dimensional finite element models that utilized nonlinear soil-structure interaction.

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

Design and Construction of a Support of Excavation System for the Silver Line Subway in Boston

New York, New York

This paper presents three (3) case histories associated with the construction of the Support Of Excavation (SOE) system for parts of the new underground (Phase II) Silver line subway system in downtown Boston. The first case study addresses the design and construction of the cantilevered sheet piles at the Fort Point Channel. The design and construction of a drift tunnel below the Russia Wharf complex is presented as the second case history. Finally, the third case study presents the analysis and design of the support of excavation system for the construction activities at the West Cofferdam. To allow the construction of the perimeter walls for an underground garage using the bentonite slurry technique, a 25 to 30 ft thick flowable fill material was placed at the west shore of the Fort Point Channel. The placed flowable fill was retained using an HZ pile system that was constructed to cantilever 25 to 30 feet. The performance of the HZ piles was within design expectations. The second case history addresses the construction of a drift tunnel located adjacent to the exterior wall of an existing tenant occupied historic building. This was undertaken to allow the permanent underpinning of said exterior wall. The third case history addresses the design and construction of a cofferdam for the construction of a cast-in-place transition between the immersed tube tunnel sections under the Fort Point Channel and the NATM tunnel under the Russia Wharf complex. A Value Engineering Cost Proposal (VECP) was proposed and implemented to eliminate 90 feet of NATM tunnel by extending the cofferdam and to reduce the number of bracing levels from five to three. The underground tunnel and the surrounding structures were analyzed using three dimensional finite element models that utilized nonlinear soil-structure interaction.