Alternative Title

Paper No. 5.01

Location

St. Louis, Missouri

Session Start Date

3-8-1998

Session End Date

3-15-1998

Abstract

This paper presents a case history on the failure of an excavation bracing system. The engineering projects involved the construction of the New World Plaza in Changchun, China. The plaza building had a 3-story deep basement which supported an 8-story building together with a 42-story main tower. The excavation area was surrounded by streets on three sides and an on-going 8-m deep excavation along the fourth side. The excavation varied from 15 m to 16 m in depth and was braced with 157 anchored cast-in-place reinforced concrete piles. The bracing system failed as soon as the design depth was reached. Primary causes of the bracing failure included improper installation of the tieback anchors, inadequate stiffness and strength of the wales, and adverse effects of freezing temperatures. It was remedied by reducing the mat foundation area together with the installation of short piles against the load bearing wall.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Fourth Conference

Publisher

University of Missouri--Rolla

Publication Date

3-8-1998

Document Version

Final Version

Rights

© 1998 University of Missouri--Rolla, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Failure of Excavation Bracing System for New World Plaza at Changchun in China

St. Louis, Missouri

This paper presents a case history on the failure of an excavation bracing system. The engineering projects involved the construction of the New World Plaza in Changchun, China. The plaza building had a 3-story deep basement which supported an 8-story building together with a 42-story main tower. The excavation area was surrounded by streets on three sides and an on-going 8-m deep excavation along the fourth side. The excavation varied from 15 m to 16 m in depth and was braced with 157 anchored cast-in-place reinforced concrete piles. The bracing system failed as soon as the design depth was reached. Primary causes of the bracing failure included improper installation of the tieback anchors, inadequate stiffness and strength of the wales, and adverse effects of freezing temperatures. It was remedied by reducing the mat foundation area together with the installation of short piles against the load bearing wall.