Deformation of a soft estuarine deposit under a geotextile reinforced embankment

This paper presents a case history of a geotextile reinforced highway embankment constructed on a soft estuarine deposit installed with prefabricated vertical drains. The case history documents the geotechnical site characterization, embankment construction, and monitoring program. The loading response of the soft estuarine soil was monitored during construction using hydrostatic profile gauges, settlement plates, pneumatic piezometers, and slope inclinometers. Settlements of up to 1.3 m were measured under the 4 m high embankment. The deformation behaviour was interpreted qualitatively from the monitoring data using the general framework of elastic-plastic soil models. The effectiveness of the monitoring program is also briefly discussed. The paper provides performance details that make this case history useful to researchers studying the loading response of soft soils under a geotextile reinforced embankment.Key words: case history, embankment, soft clay, vertical drainage, reinforcement.

[1]  Jian-Hua Yin,et al.  A new elastic viscoplastic model for time-dependent behaviour of normally and overconsolidated clays: theory and verification , 2002 .

[2]  David Hughes,et al.  An improved elastic–viscoplastic soil model , 2008 .

[3]  C. Taechakumthorn,et al.  Combined effect of PVDs and reinforcement on embankments over rate-sensitive soils , 2008 .

[4]  Jian-Hua Yin,et al.  Equivalent times and one-dimensional elastic viscoplastic modelling of time-dependent stress-strain behaviour of clays , 1994 .

[5]  J. Graham,et al.  Time effects on the stress-strain behaviour of natural soft clays , 1983 .

[6]  L. Bjerrum.  ENGINEERING GEOLOGY OF NORWEGIAN NORMALLY-CONSOLIDATED MARINE CLAYS AS RELATED TO SETTLEMENTS OF BUILDINGS , 1967 .

[7]  C. Crawford,et al.  The Influence of Rate of Strain on Effective Stresses in Sensitive Clay , 1960 .

[8]  Willy Lacerda,et al.  Embankment Failure on Clay near Rio de Janeiro , 1983 .

[9]  B Indraratna,et al.  PERFORMANCE OF EMBANKMENT STABILIZED WITH VERTICAL DRAINS ON SOFT CLAY. DISCUSSION AND CLOSURE , 1994 .

[10]  Arun J. Valsangkar,et al.  Performance of a test embankment constructed on an organic clayey silt deposit , 2001 .

[11]  J. H. A. Crooks,et al.  Effective stress paths and yielding in soft clays below embankments , 1985 .

[12]  James Graham,et al.  Viscous–elastic–plastic modelling of one-dimensional time-dependent behaviour of clays: Reply , 1989 .

[13]  Bruce L. Kutter,et al.  ELASTIC-VISCOPLASTIC MODELLING OF THE RATE-DEPENDENT BEHAVIOUR OF CLAYS , 1992 .

[14]  Robert D. Holtz,et al.  Prefabricated vertical drains (PVDs) in soft Bangkok clay: a case study of the new Bangkok International Airport project , 2002 .

[15]  Sean D. Hinchberger,et al.  Modelling the rate-sensitive characteristics of the Gloucester foundation soil , 1998 .

[16]  Guy Lefebvre,et al.  Rate effects and cyclic loading of sensitive clays , 1987 .

[17]  S. Hansbo,et al.  CONSOLIDATION BY VERTICAL DRAINS , 1981 .

[18]  C C Hird,et al.  THE THEORY OF REINFORCED EMBANKMENTS . REINFORCED EMBANKMENTS. THEORY AND PRACTICE. PROCEEDINGS OF THE CONFERENCE REINFORCED EMBANKMENTS, THEORY AND PRACTICE IN THE BRITISH ISLES, ORGANISED BY MMG CIVIL ENGINEERING SYSTEMS, HELD AT CAMBRIDGE UNIVERSITY, SEPTEMBER 27 1989 , 1990 .

[19]  R. A. Jewell,et al.  Soil reinforcement with geotextiles , 1996 .

[20]  I. C. Pyrah,et al.  Modelling the effect of vertical drains in two-dimensional finite element analyses of embankments on soft ground , 1995 .

[21]  D. Wood.  Soil Behaviour and Critical State Soil Mechanics , 1991 .

[22]  Edward Kavazanjian,et al.  A constitutive model for the stress–strain–time behaviour of ‘wet’ clays , 1985 .

[23]  Serge Leroueil,et al.  Stress–strain–strain rate relation for the compressibility of sensitive natural clays , 1985 .

[24]  A. Casacrande,et al.  Effect of Rate of Loading on the Strength of Clays and Shales at Constant Water Content , 1951 .

[25]  Charles C. Ladd,et al.  New design procedure for stability of soft clays , 1974 .

[26]  Helen Åhnberg,et al.  On the evaluation of undrained shear strength and preconsolidation pressure from common field tests in clay , 2005 .

[27]  S. Leroueil,et al.  Embankments Over Soft Soil and Peat , 2001 .