Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

Up to 9.9 m deep excavation was executed in 2002 for the LAGO Shopping Center in Constance city near the lake Bodensee (Constance lake) located north of the German alps. The excavation was 100 m long and 50 to 100 m wide and carried out in two parts. Part I of the excavation includes two basement floors and part II one basement floor. The underground condition in city Constance and the surroundings is known of a deep and soft deposit of lacustrine clay. To reduce deformations due to excavation, the part I was again partitioned in three longitudinal strips by means of intermediate sheet pile walls following the orientation of the pile grid system. The sheet pile walls were supported at the top about -4 m below the ground surface by steel struts and at the bottom of excavation by concrete slabs. Since the bottom support was intended to contribute to safety against basal and overall failure at the same time, it was connected to the piles and supposed to overcome tensile stresses. The paper shows the effects of the special construction stages followed at the site on the deformation behaviour of the excavation based on numerical analysis using the Finite Element Method (FEM). Furthermore, the time dependant pore pressure development corresponding to the special construction stages is presented. Finally, the numerical results are compared with the field measurement data.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Sixth Conference

Publisher

Missouri University of Science and Technology

Publication Date

8-11-2008

Document Version

Final Version

Rights

© 2008 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Back Analysis of a Deep Excavation in Soft Lacustrine Clays

Arlington, Virginia

Up to 9.9 m deep excavation was executed in 2002 for the LAGO Shopping Center in Constance city near the lake Bodensee (Constance lake) located north of the German alps. The excavation was 100 m long and 50 to 100 m wide and carried out in two parts. Part I of the excavation includes two basement floors and part II one basement floor. The underground condition in city Constance and the surroundings is known of a deep and soft deposit of lacustrine clay. To reduce deformations due to excavation, the part I was again partitioned in three longitudinal strips by means of intermediate sheet pile walls following the orientation of the pile grid system. The sheet pile walls were supported at the top about -4 m below the ground surface by steel struts and at the bottom of excavation by concrete slabs. Since the bottom support was intended to contribute to safety against basal and overall failure at the same time, it was connected to the piles and supposed to overcome tensile stresses. The paper shows the effects of the special construction stages followed at the site on the deformation behaviour of the excavation based on numerical analysis using the Finite Element Method (FEM). Furthermore, the time dependant pore pressure development corresponding to the special construction stages is presented. Finally, the numerical results are compared with the field measurement data.