Equivalent ‘smear’ effect due to non-uniform consolidation surrounding a PVD

This paper investigated the effect of non-uniform consolidation within a prefabricated vertical drain (PVD) unit cell on the average degree of consolidation through laboratory model tests and finite-element analysis. By considering the permeability (k) changing with the void ratio (e), the results of the finite-element analysis showed that the effect of non-uniform consolidation has a considerable effect on the average degree of consolidation of a PVD unit cell. Further laboratory model tests of a PVD unit cell were conducted, and analyses of the model test results confirmed the effect of non-uniform consolidation. Finally, a method of considering the effect of non-uniform consolidation for the analysis of PVD-induced consolidation was established with an equivalent ‘smear’ effect concept.

[1]  V. J. Moseley,et al.  Model study of seepage in smear zones around vertical drains in layered soil , 2000 .

[2]  Buddhima Indraratna,et al.  Conceptual model describing smear zone caused by mandrel action , 2013 .

[3]  Norihiko Miura,et al.  INVESTIGATION OF FACTORS AFFECTING VERTICAL DRAIN BEHAVIOR , 1999 .

[4]  J. Chai,et al.  Geocomposite induced consolidation of clayey soils under stepwise loads , 2013 .

[5]  Madhira R. Madhav,et al.  MODELLING AND STUDY OF SMEAR ZONES AROUND BAND SHAPED DRAINS , 1993 .

[6]  Jitendra Sharma,et al.  Characterization of a smear zone around vertical drains by large-scale laboratory tests , 2000 .

[7]  Jinchun Chai,et al.  Analysis of field performance of embankments on soft clay deposit with and without PVD-improvement , 2005 .

[8]  Jinchun Chai,et al.  Lateral displacement of PVD-improved deposit under embankment loading , 2014 .

[9]  Buddhima Indraratna,et al.  Soil disturbance analysis due to vertical drain installation , 2015 .

[10]  J. Chu,et al.  Improved Vacuum Preloading Method for Consolidation of Dredged Clay-Slurry Fill , 2016 .

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

[12]  Jinchun Chai,et al.  1D deformation induced permeability and microstructural anisotropy of Ariake clays , 2015 .

[13]  Hyeong J Kim,et al.  Stochastic cost optimization of ground improvement with prefabricated vertical drains and surcharge preloading , 2014 .

[14]  One-dimensional consolidation of layered soils , 1996 .

[15]  Jinchun Chai,et al.  Effect of hydraulic radius on long-term drainage capacity of geosynthetics drains , 2004 .

[16]  C. Ng,et al.  An analytical solution for consolidation with vertical drains under multi-ramp loading , 2015 .