Laboratory Studies on Property Changes in Surrounding Clays Due to Installation of Deep Mixing Columns

This paper has identified six major factors causing property changes in surrounding soils during and after installation of deep mixing columns: soil thixotropy, soil fracturing, cement penetration and diffusion, cementation, consolidation, and heating. Laboratory tests were performed to investigate the effects of soil thixotropy, soil fracturing, and cementation in a soft marine clay, Ariake clay. Laboratory tests were conducted to evaluate property changes in surrounding clays due to installation of deep mixing columns. Test results showed that an influential zone of property changes existed in surrounding clay ranging from the edge of the columns to the distance of about twice the radius of the columns. Within this influential zone, water content decreased as samples neared the columns, while pH values and electric conductivity increased. Test results also showed that undrained shear strengths of the surrounding clays decreased during mixing but regained after a 7-day curing period and continued increasing during 28 days in this study.

[1]  N. Miura,et al.  Mechanisms Controlling the Undrained Strength Behavior of Remolded Ariake Marine Clays , 2002 .

[2]  Shui-Long Shen,et al.  Soil Fracturing of the Surrounding Clay during Deep Mixing Column Installation. , 1999 .

[3]  Ronald E. Smith.  Introduction of Michael W. O'Neill, Thirty-Fourth Terzaghi Lecturer, 1998, Boston, Massachusetts , 2001 .

[4]  S. Shen,et al.  Evaluation of Property Changes in Surrounding Clays due to Installation of Deep Mixing Columns , 2003 .

[5]  Norihiko Miura,et al.  EXPERIMENTAL STUDY ON SKIN RESISTANCE OF PILE IN SOFT CLAY , 1995 .

[6]  W. Busscher.  Fundamentals of Soil Behavior , 1994 .

[7]  Masami Ohtsubo,et al.  Ariake bay quick clays: a comparison with the general model. , 1995 .

[8]  Shui-Long Shen,et al.  STRENGTH CHANGE OF CLAY IN THE VICINITY OF SOIL-CEMENT COLUMN , 1998 .

[9]  S. Shen,et al.  Interaction mechanism between deep mixing column and surrounding clay during installation , 2003 .

[10]  C. P. Wroth,et al.  An analytical solution for the consolidation around a driven pile , 1979 .

[11]  Michael W. O'Neill,et al.  Side resistance in piles and drilled shafts , 2001 .

[12]  M. Ohtsubo,et al.  Depositional and post-depositional geochemistry, and its correlation with the geotechnical properties of marine clays in Ariake Bay, Japan , 1995 .

[13]  J Biarez,et al.  BEARING CAPACITY AND SETTLEMENT OF PILE FOUNDATIONS , 1977 .

[14]  G. Rajasekaran,et al.  Lime Stabilization Technique for the Improvement of Marine Clay. , 1997 .

[15]  S. N. Rao,et al.  EFFECT OF LIME ON CATION EXCHANGE CAPACITY OF MARINE CLAY. TECHNICAL NOTE , 1997 .

[16]  Mark Randolph,et al.  DRIVEN PILES IN CLAY - THE EFFECTS OF INSTALLATION AND SUBSEQUENT CONSOLIDATION , 1979 .

[17]  Dennes T. Bergado,et al.  Soft Ground Improvement in Lowland and Other Environments , 1996 .

[18]  G G Mayerhof,et al.  Bearing Capacity and Settlement of Pile Foundations , 1976 .

[19]  L. Murdoch,et al.  Hydraulic fracturing of soil during laboratory experiments Part 1. Methods and observations , 1993 .