Effect of Prefabricated Vertical Drain Clogging on the Rate of Consolidation: A Numerical Study

Abstract

Ground treatment of soft soil deposits by prefabricated vertical drains (PVDs) is a common practice in geotechnical engineering. The PVDs accelerate the consolidation process and help to rapidly increase the strength and stiffness of soil. Certain operational problems, such as clogging, are inherent to PVDs. The fine particles in the soil may become entrapped within the fibers of the filter, i.e. the geotextile, surrounding the PVD. If the pores of the filter sleeve are clogged, the discharge capacity of the PVD reduces and, consequently, the consolidation process is impeded. In this paper, a numerical study is carried out to investigate the effect of PVD geotextile filter clogging on the rate of soil consolidation. The rate of consolidation decreases with increasing clogging and is a function of the location of the clogged area in the PVD. In the parametric study, the PVD was sequentially clogged and its effect studied. The effect of smear was also included in the analysis.