Nonlinear Finite Element Analysis of Strip
Footing on Reinforced Clay

 

Dilip Kumar Maharaj

Assistant Professor, Civil Engineering Group
Birla Institute of Technology and Science, Pilani, Rajasthan, India
e-mail:dilip_maharaj@yahoo.com, dkm@bits-pilani.ac.in

ABSTRACT

 

In this paper the results based on two dimensional Nonlinear Finite Element Analysis under plane strain condition have been presented for strip footing on reinforced clay.The footing and soil have been discretized by four noded isoparametric finite elements while reinforcement has been modelled by four noded one dimensional finite element.The soil has been idealized as Drucker-Prager elastoplastic medium. The effect of the embedment depth of the first layer of reinforcement, spacing of reinforcement layers, number of reinforcement layers and the size of the reinforcement on the settlement of the footing have been investigated. The four noded one dimensional isoparametric finite element has been found successful in modelling reinforcement in finite element analysis of reinforced clay. In case of single layer of reinforcement below footing an optimum embedment depth of reinforcement is there at which maximum reduction in settlement has been found. Settlement has been found to reduce with increase in reinforcement size both for single layer as well as for multi layers of reinforcement. The effect of increase in stiffness of the reinforcement has been found to reduce the settlement of the footing both for single and multi layers of reinforcement. Also it has been found that increasing stiffness beyond a certain value is not effective in settlement reduction. The settlement has been found to reduce with increase in number of reinforcement layers. The load carrying capacity of footing has been found more on soil in which reinforcements are provided at closer spacing. The load carrying capacity of footing has also been found more on soil in which stiffness of reinforcement considered is more. The result obtained from the 2D formulation considered compare well with the literature.

Keywords: Reinforced earth, analysis, footing, finite element method

 

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