EFFECTS OF JET GROUTING ON ADJACENT GROUND AND STRUCTURES

In Singapore, for deep excavations in thick layers of soft soils adjacent to sensitive structures--such as Mass Rapid Transit structures and old buildings--the use of diaphragm walls alone is often insufficient to achieve the targeted maximum movement. The basement excavation of the Singapore Post Center involved extensive jet grouting to improve the soft marine clay present within the excavation. The treated soil mass, with much improved strength and deformation characteristics, was intended to act as an internal strut below the bottom of the excavation level, reducing movements caused by the basement excavation. This paper presents the performance of production grouting carried out during the construction of the building's basement. Results of monitoring suggest that the jet grouting caused the retaining diaphragm walls to move between 9.7 mm and 36.4 mm. The soils behind the walls also moved away from the excavation. Movements ranged from 35.3-53.6 mm within 1-2 m from the wall to 13.5-32.8 mm at 4.5-20.5 m away from the wall. The recorded soil heave ranged from 2 mm to 24 mm, with the majority of the measurements being less than 10 mm. The backward movements induced by the production grouting are similar to those induced by preloading a strut of a braced excavation system. Provided the backward movements do not exceed the allowable limits, they would help in minimizing the ultimate positive movements induced by the subsequent basement excavation. The jet grouting also induced some bending moments on the diaphragm walls and caused the adjacent structures to tilt and move away from the jet grout area.

• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/oclc/3519342
• Corporate Authors:

  American Society of Civil Engineers

  1801 Alexander Bell Drive
  Reston, VA  United States  20191-4400
• Authors:
  • Wong, I H
  • Poh, T Y
• Publication Date: 2000-3

Language

• English

Media Info

• Features: Appendices; Figures; References; Tables;
• Pagination: p. 247-256
• Serial:
  • Journal of Geotechnical and Geoenvironmental Engineering
  • Volume: 126
  • Issue Number: 3
  • Publisher: American Society of Civil Engineers
  • ISSN: 1090-0241
  • Serial URL: http://ojps.aip.org/gto

Subject/Index Terms

• TRT Terms: Basements; Bending moments; Construction; Diaphragm walls; Earth pressure; Excavations; Foundation engineering; Foundation soils; Grouting; Marine clays; Monitoring; Piezometers; Rail transit stations; Rapid transit; Retaining walls; Soil mechanics; Soil structure interaction; Structural mechanics; Struts; Viaducts
• Uncontrolled Terms: Heaving; Jet grouting
• Geographic Terms: Singapore
• Subject Areas: Bridges and other structures; Construction; Design; Geotechnology; Highways; Public Transportation; I24: Design of Bridges and Retaining Walls; I42: Soil Mechanics;

Filing Info

• Accession Number: 00788970
• Record Type: Publication
• Contract Numbers: CMS-9309345, 32451-GS-ISP, 32708-AAS
• Files: TRIS
• Created Date: Mar 22 2000 12:00AM