ABSTRACT
The paper presents two-dimensional (2D) finite element (FE) modelling of an embankment preload supported over a layered soil comprising soft cohesive soil overlain by sandy layers. The present study is based on ground improvement through surcharge preloading and prefabricated vertical drain (PVD) installation for the development of an Ultra Mega Power Project in Krishnapatnam (KUMPP), Andhra Pradesh, India. PLAXIS line drains are utilized for representing the PVDs. The equivalent plane strain permeability of the soft clays undergoing radial drainage is assessed through Hird’s approach. Mohr-Coulomb (MC) material is chosen to represent the constitutive behavior of the underlying subsurface layers as well as the surcharge fill. A comparative assessment is carried out in terms of surface settlement and excess pore pressure in the clayey layer, highlighting the benefits of using PVDs along with preloading. Moreover, the study also points out the effect of smear zone properties around the PVDs on the consolidation settlement of the clay layer supporting the embankment preload.
