Dipanjan Basu

University of Waterloo, Civil and Environmental Engineering, Faculty Member

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My research and teaching interests span soil mechanics, rock mechanics, solid mechanics, numerical and analytical methods, soil structure interaction, and sustainability. Currently, I am working on wind energy foundations, sustainability assessment in geotechnical engineering, compressed air energy storage, thermo-mechanical stress management in rock, enhanced geothermal systems, ground source heat pump, moving load soil structure interaction, and a few more topics.

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Papers by Dipanjan Basu

Geomechanics and geoengineering : an international journal

Resilience — A Requirement of Sustainable Geotechnical Practice

GEOSTRATA Magazine, 2020

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PVD-Aided Consolidation with Spatial Variations in Soil Properties and Initial Excess Pore Pressure

International Journal of Geosynthetics and Ground Engineering, 2022

Dynamic response analysis of Euler–Bernoulli beam on spatially random transversely isotropic viscoelastic soil

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications, 2022

A novel dynamic soil-structure interaction model is developed for analysis for Euler–Bernoulli be... more A novel dynamic soil-structure interaction model is developed for analysis for Euler–Bernoulli beam rests on a spatially random transversely isotropic viscoelastic foundation subjected to moving and oscillating loads. The dynamic equilibrium equation of beam-soil system is established using the extended Hamilton's principle, and the corresponding partial differential equations describing the displacement of beam and soil and boundary conditions are further obtained by the variational principles. These partial differential equations are discretized in spatial and time domains and solved by the finite difference (FD) method. After the differential equations of beam and soil are discretized in the spatial domain, the implicit iterative scheme is used to solve the equations in the time domain. The solving result shows the FD method is effective and convenient for solving the differential equations of beam-soil system. The spring foundation model adopted the modified Vlasov model, wh...

A Quantitative Sustainability Indicator System for Pile Foundations

GeoCongress 2012, 2012

Nonlinear elastic analysis of laterally loaded piles

The objective of this paper is to describe a new continuum-based analysis for predicting the nonl... more The objective of this paper is to describe a new continuum-based analysis for predicting the nonlinear response of pile foundations, subjected to static lateral loads. In the analysis, the pile is modeled as an elastic Euler-Bernoulli beam and the soil as a continuum with nonlinear elastic properties that is described by a modulus degradation relationship. The soil displacements are assumed to be a product of separable functions and the principle of virtual work is applied to obtain the governing differential equations describing the pile and soil displacements, which are solved numerically using the one-dimensional finite difference method, in an iterative scheme. The reliability of the results obtained from the present analysis is verified with the results equivalent 3-D finite element analysis. RÉSUMÉ L’objectif de cet article est de décrire un nouveau continuum basé analyser pour prédire la réponse non linéaire des fondations de pieu, soumis à des charges statiques de difuso. Da...

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Effect of Temperature on Hysteretic Behavior of Water Retention Capacity for Clay–Sand Liners

Indian Geotechnical Journal, 2021

The effect of temperature on the hysteretic behavior of water retention is of significant importa... more The effect of temperature on the hysteretic behavior of water retention is of significant importance for unsaturated clays used as barriers for high-level radioactive waste disposal or as cover layers in waste management facilities. This study aims at investigating the effect of ambient temperature on the hysteretic behavior of water retention curves of sand-expansive clay mixtures that can be used as barriers. Two specimens consisting of mixtures of sand and expansive clay with clay contents of 15% and 30% and a specimen of pure expansive clay are considered in the study. To identify the possible thermal effects, drying–wetting soil–water retention curves for these soils are determined at selected ambient temperatures of 7, 24, and 47 °C. The vapor equilibrium technique is used to cover a wide range of suction. Different saturated salt solutions and concentrations are prepared and calibrated under nominated temperatures. The area of the hysteresis enclosed between the drying and wetting curves is calculated and used as a measure of the degree of hysteresis induced under different temperatures. The study indicates that ambient temperature has a significant impact on the hysteretic behavior of soil–water retention curves. The degree of hysteresis between drying and wetting curves tends to decrease linearly with an increase in the temperature for the investigated range of 7–47 °C.

Erratum for “Settlement Estimation of Piled Rafts for Initial Design” by Priyanka Bhartiya, Tanusree Chakraborty, and Dipanjan Basu

Journal of Geotechnical and Geoenvironmental Engineering, 2020

The following corrections should be made to the original paper: 1. In the section "Unpiled Raft S... more

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Probabilistic analysis of monopile-supported offshore wind turbine in clay

Soil Dynamics and Earthquake Engineering, 2018

The dynamic behaviour of monopile supported offshore wind turbines (OWTs) is considerably influen... more The dynamic behaviour of monopile supported offshore wind turbines (OWTs) is considerably influenced by inherent variabilities of soil properties and loading. This study investigates the effect of uncertainties in soil shear strength properties, and wind and wave loads on the reliability of OWT structures founded in clay. The OWT system is modeled as an Euler-Bernoulli beam and soil-structure interaction is incorporated using the American Petroleum Institute based cyclic p-y relationships. The uncertainties in soil undrained shear strength, in the parameters and equations of the p-y method, and in wind velocity are considered. Random wave loads are estimated from the code specified power spectral density function of the vertical sea surface elevation. Uncertainties in OWT responses are quantified using Monte Carlo simulations. The effects of length and diameter of the monopile, vertical sea surface displacement spectrum, and the probability distribution of wind speed on the dynamic responses of OWT are investigated. The study shows that the various power spectral density functions of wave surface displacement and various probability density functions of wind speed have a marginal effect on the response and fatigue life of OWTs. The mean fundamental frequency of the OWT system is significantly affected by the variability of the undrained shear strength of clayey soil.

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Dynamic analysis of axially loaded end-bearing pile in a homogeneous viscoelastic soil

Soil Dynamics and Earthquake Engineering, 2018

A new approximate analysis technique is developed to obtain the steady-state response of axially ... more A new approximate analysis technique is developed to obtain the steady-state response of axially loaded pile embedded in a homogeneous, isotropic soil, and resting on a rigid base. In the analysis, the soil is modeled as an axisymmetric linear viscoelastic continuum with frequency independent hysteretic material damping and the pile is modeled as an elastic Euler rod with a circular cross-section. The soil displacement in the vertical direction is expressed as a product of separable functions, while the radial displacement is assumed to be zero for mathematical simplicity; although the effect of the radial displacement is indirectly taken into account by modifying the soil modulus. The Extended Hamilton's principle in conjunction with the calculus of variations is used to obtain the differential equations governing pile and soil displacements and the relevant boundary conditions. The pile and soil displacement equations are solved analytically following an iterative algorithm. The accuracy of the analysis is ensured by comparing the pile responses obtained from this analysis with those obtained by other methods available in the literature. A parametric study is performed to investigate the influence of the pile and soil parameters on the axial dynamic pile-head impedances. The plots developed from the parametric study can be used in the design.

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Novel evaluation of bender element transmitter response in transparent soil

Géotechnique, 2019

Bender elements (BEs) are commonly used by geotechnical laboratories worldwide to measure the she... more Bender elements (BEs) are commonly used by geotechnical laboratories worldwide to measure the shear-wave velocity of soils. However, the actual behaviour of BEs inside the soil specimen has never been directly measured. There is experimental, numerical and analytical evidence that the shape and frequency content of the actual transmitter movement are different from the shape and frequency content of the input voltage signal, although this disparity has never been validated for BEs placed inside a soil specimen. In order to systematically investigate the disparity between the input signal and the actual transmitter response and to advance the understanding of the frequency response of the transmitter inside the soil, an experimental programme is designed to measure, for the first time, the responses of BEs placed inside soil specimens. To capture the transmitter response when placed inside the soil, a transparent granular soil is used to allow penetration of a laser beam from a laser...

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An Integrated Approach for Resilience and Sustainability in Geotechnical Engineering

Indian Geotechnical Journal, 2018

Excessive consumption of energy and natural resources and generation of pollutants are the main r... more Excessive consumption of energy and natural resources and generation of pollutants are the main reasons why sustainable practices should be strongly advocated in geotechnical engineering. Resilience, on the other hand, is also important as it improves the ability to cope with uncertain yet extreme events that may occur over the long life cycle of geotechnical infrastructure. There has been increasing recognition that sustainability needs to be incorporated and practiced in geotechnical engineering, but little attention has been paid on incorporating resilience although sustainability and resilience share similar objectives and values. A geotechnical infrastructure may not be truly sustainable if it is not resilient against extreme events and climate change because undesirable consequences caused by the failure of geotechnical infrastructure make the system unsustainable. It is important that the concepts of sustainability and resilience are concurrently considered to ensure that resilience in geotechnical infrastructure is developed while sustainable practices are performed. This paper presents an overview of the key concepts of sustainability and resilience with a particular emphasis on resilience in order to understand the differences and connections between the two. The quantitative and qualitative assessment methods of resilience are also discussed. An integrated assessment framework for the quantification of resilience and sustainability of geotechnical infrastructure is proposed, which is developed based on the driver-pressure-state-impact-response (DPSIR) framework.

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Analysis of Beams on Heterogeneous and Nonlinear Soil

International Journal of Geomechanics, 2016

AbstractA new method for nonlinear analysis of Euler-Bernoulli beams resting on heterogeneous, mu... more AbstractA new method for nonlinear analysis of Euler-Bernoulli beams resting on heterogeneous, multilayered soil is presented. The governing differential equations for beam and soil displacements are obtained using the principle of virtual work, and these equations are solved using one-dimensional finite-element and finite-difference methods. Using the analysis, beam displacements can be obtained as a nonlinear function of applied loads if the beam and soil geometry and properties are known. The distinct feature of the analysis is that beam responses with accuracy comparable with those obtained from equivalent two-dimensional finite-element analysis are obtained within seconds. Examples illustrate how the proposed method can be applied in practice to obtain beam displacements in soil deposits that are characterized with nonlinear stress-strain relationships, have multiple layers, and have a modulus varying spatially within each soil layer. Parametric studies are performed that highlight the effects of soi...

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

Geosynthetics International, 2000

Ground treatment of soft soil deposits by prefabricated vertical drains (PVDs) is a common practi... more 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.

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Response of laterally loaded rigid monopiles and poles in multi-layered elastic soil

Canadian Geotechnical Journal, 2016

A new method of analysis of rigid monopiles and poles based on the principle of virtual work is d... more A new method of analysis of rigid monopiles and poles based on the principle of virtual work is developed. The analysis considers three-dimensional interaction between the rigid pile and surrounding soil, and quickly produces pile response while maintaining accuracy comparable with that obtained from equivalent finite element analysis. Using this method, a systematic parametric study is performed to investigate the response of rigid piles in soil profiles where properties change either continuously or discretely with depth. Equations are developed based on the parametric study, which can be used to calculate pile head displacement and rotation. Numerical examples are provided that illustrate the use of the method.

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Effect of Climate Change on the Reliability of Offshore Wind Turbine Foundations

Geo-Chicago 2016, 2016

Ticks carry several human pathogenic microbes including Borreliae and Flavivirus causing tick-bor... more Ticks carry several human pathogenic microbes including Borreliae and Flavivirus causing tick-born encephalitis. Ticks can also carry DNA of Chlamydia-like organisms (CLOs). The purpose of this study was to investigate the occurrence of CLOs in ticks and skin biopsies taken from individuals with suspected tick bite. DNA from CLOs was detected by pan-Chlamydiales-PCR in 40% of adult ticks from southwestern Finland. The estimated minimal infection rate for nymphs and larvae (studied in pools) was 6% and 2%, respectively. For the first time, we show CLO DNA also in human skin as 68% of all skin biopsies studied contained CLO DNA as determined through pan-Chlamydiales-PCR. Sequence analyses based on the 16S rRNA gene fragment indicated that the sequences detected in ticks were heterogeneous, representing various CLO families; whereas the majority of the sequences from human skin remained "unclassified Chlamydiales" and might represent a new family-level lineage. CLO sequences detected in four skin biopsies were most closely related to "uncultured Chlamydial bacterium clones from Ixodes ricinus ticks" and two of them were very similar to CLO sequences from Finnish ticks. These results suggest that CLO DNA is present in human skin; ticks carry CLOs and could potentially transmit CLOs to humans.

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Response of Beams on Nonlinear Foundation

IFCEE 2015, 2015

The paper presents a new method for nonlinear analysis of Euler-Bernoulli beams on soil. The gove... more The paper presents a new method for nonlinear analysis of Euler-Bernoulli beams on soil. The governing differential equations for beam and soil displacements are derived using the principle of virtual work, and these equations are solved using finite element and finite difference methods, respectively. Using the analysis, beam displacements can be obtained very quickly as a nonlinear function of applied loads if the beam and soil geometry and properties are known. The advantage of the method is that it is based on robust continuum theory yet produces results as fast as those produced by the spring models.

Probabilistic analysis of monopile-supported offshore wind turbine in clay

Soil Dynamics and Earthquake Engineering, 2018

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Rainfall induced slope instability – the role of partial saturation

Influence of the disturbed zone on consolidation aided by prefabricated vertical drains

Dipanjan Basu

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