This paper presents critical assessment of codal provisions to determine lateral stability of a well foundation. A two-dimensional finite element model of soil–well foundation system is developed for this study. The well foundation is modeled as a linear elastic body, whereas the soil as a nonlinear elasto-plastic material which is defined using multi-yield surface plasticity model. Interface between the well foundation and the adjoining soil is defined using constitutive relationships describing relative sliding and separation at the interface. Assumptions considered in the existing codal provisions to determine lateral stability of a well foundation are evaluated in light of the results obtained from the present study. The present study shows that the mechanism of deformation of laterally loaded soil–well foundation system obtained in this study differs from that considered in the existing codal provisions. It is observed that the existing codal provisions overestimate the lateral load capacity of a well foundation. © 2020, Indian Geotechnical Society.

Gyan Vikash

Civil Engineering

(SoE) School of Engineering

Rachamandugu R.

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Shiv Nadar University

Indian Geotechnical Journal

Bulletin of Earthquake Engineering

Earthquake safety in India: achievements, challenges and opportunities

Earthquake Spectra

Significance of Interface Nonlinearity on the Seismic Response of a Well-Pier System in Cohesionless Soil

The authors refer to the laboratory testing carried out on model caisson embedded in marine clay collected from the Chennai coast in India. The response of lateral load-ground level deflection of caissons under static and cyclic lateral loading is presented and discussed for the varied parameters such as caisson embedment depth ratio (L/D), load eccentricity ratio (e/D), and undrained strength (s u) of clay. The results showed that as the caisson L/D increases, the lateral load required to cause a specified ground level deflection increases. At a given lateral load, the deflection levels are increased as the load eccentricity ratio increases from 0.5 to 2.0. As L/D increases from 2 to 3, the increase in the ultimate lateral capacity is found to be 1.8 to 2.0 times. Similarly, for the change in L/D from 3 to 4, this increase in capacity is found to be 1.6 to 1.8 times at all the undrained strength values and e/D values tested. From the cyclic load test results, it was noticed that the deflections mobilized at the cyclic load ratio (CLR = 0.6) were so small and these are hardly 1% to 2% of the diameter of the caisson. A marked increase in the ground level deflection up to about 900 cycles was observed and thereafter the deflection almost remained the same. © 2012 Copyright Taylor and Francis Group, LLC.

Marine Georesources and Geotechnology

Lateral Load: Deflection Response of an Embedded Caisson in Marine Clay

Soil Dynamics and Earthquake Engineering

Simplified seismic analysis of soil–well–pier system for bridges

A simplified model for lateral response of large diameter caisson foundations—Linear elastic formulation

An Assessment of Codal Provisions for Analysis of Laterally Loaded Well foundations