Deep Soil Mixing and its application

1
Deep Soil Mixing and its application

• Presenter Prashant Shirodkar
• Class Instructor Dr. Beena Sukumaran
• Subject Earth Retaining Structure

2
Outline

• Retaining structure
• Application of DSM
• Design of DSM
• Construction of DSM
• Case Studies
• Summary

3
Retaining structure in soft soil

• Sheet piling
• Water Seepage
• Diaphragm wall
• Thick cast in place
• R/C wall
• Deep Soil Mixing
• Mechanical mixing
• with insitu soil

4
Application of DSM wall

• Hydraulic cut-off wall (Japan, US)
• Excavation support wall (Japan, china, US)
• Ground treatment (Japan, china, US)
• Liquefaction mitigation (Japan, US)
• Environmental remediation (US, UK)

5
Design of DSM wall

• Site Investigation
• Ground Settlement Sensitivity
• Vibration sensitivity
• High Ground Water Table
• Soft Soil
• Type selection
• Wall, Grid, block
• Performance Criteria selection
• Depend upon Type of soil and structure

6
Design of DSM wall

• Seepage analysis
• Chart or computer analysis
• (2D or 3D)
• External Stability Analysis
• Method of Slice etc.
• Analysis and Design of DSM wall
• Assuming proper repeatable section and end
  condition

Ordinary Method of Slice (Anderson and Richard,
1997)
7
Design of DSM wall

• Vertical bearing capacity
• Summing forces acting on soil
• Deflection and deformation

8
Design of DSM wall
9
Construction of DSM wall
Double Auger
Cutter post
Mixing of soil with Cementatious material
10
Case Study 1

• Stabilized the WT
• Lateral movement was within limit (lt25 mm)

912 m of depress roadway At Lake Parkway Freeway
Section of wall
11
Case Study 2

• Site contaminated with
• metal and organic
• compound
• Different combination
• of grout (7)
• Performance
• Unconfined compressive strength (Increased)
• Permeability (constant)
• TCLP Leachate pH (Decreased)

12
Case Study 3

• Performance
• Lateral Displacement
• Shear Strain

Section of wall
Plan view of the site
13
Case Study 4

• Uniform Deflection of wall
• 8 and 16 mm settlement of adjacent
  structure
• Maximum stress was within limit

14
Summary

• DSM could be successfully use in geoenvironmental
  application.
• DSM could be used successfully for various site
  condition by modifying its geometry.

15
Questions??