Location

San Diego, California

Session Start Date

5-24-2010

Session End Date

5-29-2010

Abstract

A case history of constructing offshore guide dikes on soft clay is presented in this paper. The guide dikes were constructed near the Shanghai Port, China, for deepening of navigation channel along the Yangtze Estuary. The guide dikes were designed as gravity retaining structures using prefabricated, semi-circular shaped concrete caissons. Some sections of the guide dikes were installed on a thick layer of soft soils. During the construction, the caissons in one section failed under a heavy storm. The causes of failure were investigated by running dynamic triaxial tests on undisturbed soil samples taken from the construction site, associated with the FE analysis. It was found that the dike failure was induced by the strength weakening of the soft soil layer below the foundation. The design of the guide dike and the soil improvement works are described in this paper. Surcharge preloading and prefabricated vertical drains was adopted to improve the soft soils below the caisson. The soil improvement measure was proven to be effective in maintaining the stability of the guide dikes against subsequent heavy storms.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Meeting Name

Fifth Conference

Publisher

Missouri University of Science and Technology

Publication Date

5-24-2010

Document Version

Final Version

Rights

© 2010 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

Share

COinS
 
May 24th, 12:00 AM May 29th, 12:00 AM

Wave-Induced Strength Weakening of Soft Clay Below a Prefabricated Caisson Dike

San Diego, California

A case history of constructing offshore guide dikes on soft clay is presented in this paper. The guide dikes were constructed near the Shanghai Port, China, for deepening of navigation channel along the Yangtze Estuary. The guide dikes were designed as gravity retaining structures using prefabricated, semi-circular shaped concrete caissons. Some sections of the guide dikes were installed on a thick layer of soft soils. During the construction, the caissons in one section failed under a heavy storm. The causes of failure were investigated by running dynamic triaxial tests on undisturbed soil samples taken from the construction site, associated with the FE analysis. It was found that the dike failure was induced by the strength weakening of the soft soil layer below the foundation. The design of the guide dike and the soil improvement works are described in this paper. Surcharge preloading and prefabricated vertical drains was adopted to improve the soft soils below the caisson. The soil improvement measure was proven to be effective in maintaining the stability of the guide dikes against subsequent heavy storms.