Location

Arlington, Virginia

Session Start Date

8-11-2008

Session End Date

8-16-2008

Abstract

The trench remixing and deep wall method (TRD) is a one-phase process for excavation and in situ mixing of a vertical barrier. While the TRD method was developed and has been widely employed in Japan for more than a decade, it has only recently been used in the United States. Since the TRD method mixes the entire depth of the vertical profile, this method can be used to construct a more homogeneous wall than other in situ methods. Using a large revolving chain and cutter bar, the TRD equipment simultaneously excavates and mixes in situ soils and added slurry resulting in a continuous soil mixed wall. The blend of slag, Portland cement and clay-water slurry is added as the excavation moves along the alignment of the barrier and produces continuous vertical mixing of in situ soils with the added blend. This paper presents a case study of the first TRD project in the United States involved the construction of closed cells to allow full evaluation of the method. This installation was part of a larger evaluation of the use of a vertical passive barrier to prevent the intrusion of salt water into fresh ground water aquifers in Southern California. The paper describes the site characterization, an extensive laboratory study conducted to investigate the appropriate mix design, field construction and post-construction testing. The case study shows the methodology used to develop design mixtures and presents information showing the successful completion of a barrier wall by the TRD method.

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

Share

 
COinS
 
Aug 11th, 12:00 AM Aug 16th, 12:00 AM

Alamitos Gap: A Case Study Using the Trench Remixing and Deep Wall Method

Arlington, Virginia

The trench remixing and deep wall method (TRD) is a one-phase process for excavation and in situ mixing of a vertical barrier. While the TRD method was developed and has been widely employed in Japan for more than a decade, it has only recently been used in the United States. Since the TRD method mixes the entire depth of the vertical profile, this method can be used to construct a more homogeneous wall than other in situ methods. Using a large revolving chain and cutter bar, the TRD equipment simultaneously excavates and mixes in situ soils and added slurry resulting in a continuous soil mixed wall. The blend of slag, Portland cement and clay-water slurry is added as the excavation moves along the alignment of the barrier and produces continuous vertical mixing of in situ soils with the added blend. This paper presents a case study of the first TRD project in the United States involved the construction of closed cells to allow full evaluation of the method. This installation was part of a larger evaluation of the use of a vertical passive barrier to prevent the intrusion of salt water into fresh ground water aquifers in Southern California. The paper describes the site characterization, an extensive laboratory study conducted to investigate the appropriate mix design, field construction and post-construction testing. The case study shows the methodology used to develop design mixtures and presents information showing the successful completion of a barrier wall by the TRD method.