Chaminda S. Bandara

University of Peradeniya | UOP · Department of Civil Engineering

Ballasted tracks are being overstressed as the demand for faster and heavier trains grows, resulting in excessive deterioration, frequent maintenance, and increased life-cycle cost of the track. Therefore, advancements in track constructions, such as elastic inclusions, to improve track performance and minimize maintenance frequency while enhancing...

Mass irregular buildings are more vulnerable to seismic loading depending on their degree of irregularity. Therefore, design codes/standards prescribed different irregularity limits to identify the mass irregular buildings. However, design codes/standards are incapable of quantifying the degree of mass irregularity based on its elevation in the bui...

This study explores the lateral behaviour and performance of hollow steel box piers under simultaneous axial and cyclic lateral loading. First, the motivation of the study and the lateral performance evaluation indices were described briefly. Following that, the experimental and numerical results were compared, and the trustworthiness of the numeri...

Fatigue is a significant parameter in steel structures, especially in bridge structures under heavy repetitive loading. Also, steel bridges are used in various sectors of the construction industry, such as; highway and railway bridges, pipe-supporting bridges, and footbridges. The natural frequency method, mode shape method, modal strain energy met...

External claddings have been identified as a more critical component in buildings than before due to many catastrophic fire incidents that occurred in recent decades. Present-day engineers seek claddings with improved fire performance to satisfy state/government mandates against fire hazards. It is challenging to cater to the increased cladding dem...

To lessen the track deterioration and the life cycle cost of ballasted railway tracks, the application of energy-absorbing rubber pads such as rail pads (RP), under sleeper pads (USP), and under ballast mats (UBM) is becoming popular in many countries. Recent experimental studies explore the ability of these rubber pads to reduce ballast layer stre...

The high-mast lighting towers that are subjected to cyclic wind loadings (due to vortex shedding action) tend to fail due fatigue failure. From past studies, based on the testing and finite element analysis, it was found that geometry of the mast arm and base connection are highly influencing on the fatigue performance of the high-mast lighting tow...

Depth-sensing instrumented indentation test or hardness test is a very easy, quick and inexpensive, semi-destructive technique that can be used to determine the mechanical properties of materials on small scales (on nano or micrometer scales). During the past two decades, inverse analysis methods were developed to determine the true stress–strain b...

A numerical investigation on the effective use of low yield point (LYP) steel as a replaceable energy dissipation mechanism in a thin-walled steel box column is presented in this paper. Three column sections with modified cross-section using four L angles and replaceable LYP steel plates were tested under constant axial and lateral cyclic loading,...

Masonry structures are widespread around the world due to their relative low cost, availability of raw materials and ease of construction. The prediction of structural masonry behaviour is complex, especially under extreme loading conditions such as earthquake excitation. Nowadays, numerical simulations are used in many engineering applications inc...

Purpose The purpose of the study is to mainstream the disaster risk reduction (DRR) and disaster resilience measures into the GreenSL® building rating system in Sri Lanka to demonstrate a more holistic approach in achieving sustainability with resilience. Design/methodology/approach First, a comprehensive literature review was carried out on green...

Currently, there is an increasing demand for rail transport from a growing and urbanizing population worldwide as it is a resource-efficient transport system. Improving the performance of rail tracks to cater faster and heavier trains is inevitable. The conventional rail track system consists of rails, fastening systems, sleepers, ballast, sub-ball...

Construction could be considered an industry that provides a major contribution to the economy, society, and the environment. However, it is often criticised due to its unethical and substandard practices. Thus, effective Corporate Social Responsibility (CSR) practices could be utilised to minimise the adverse effects in the industry and lead to su...

Bamboo has been used as a construction material, since ancient times and has a long tradition of being used as a structural material in the construction industry due to its availability and low cost. However, due to inadequate mechanical properties of bamboo, modern technologies should be identified to improve these properties to enhance the long d...

Recent developments on high-mast arm structures have increased awareness of the fatigue behavior associated with these structures. Mast arm structures that are subjected to cyclic loading conditions tend to fail due to fatigue failure. Size and thickness of base plate, geometry and thickness of mast arm, welding thickness and numbers of anchor bolt...

Disaster risk in Sri Lanka has been increasing mainly due to rapid unplanned commercialization and development of cities, infrastructure with poor quality, and the impacts of climate change which has exposed the built environment severely to natural hazards. Out of all the hazards, floods, landslides, heavy winds and tsunamis have caused the highes...

Rail transport provides assured services to commuters and freights more economically. In conventional rail tracks, rails are rested on sleepers on top of the layered substructure. The ballast layer is the prominent load-bearing layer in the substructure. It facilitates quick drainage through its interconnected larger voids. Ballast is a highly angu...

The aim of this research is to study the fatigue performance of the high-mast lighting towers made up of steel under various thicknesses of the mast-arm wall subjected to along and vortex shedding wind action. For these kinds of wind sensitive structures, it is necessary to predict the total damage induced by the wind action. In order to estimate t...

Purpose - The current National Early Warning System for Sri Lanka (NEWS: SL) was established after the devastations of the Indian Ocean Tsunami in 2004. Although early warning (EW) systems and evacuation procedures are in place, several areas which need improvements have been emphasized in recent studies carried out in the country. Therefore, this...

The behaviour of Reinforced Concrete (RC) beams is highly complex due to different types of failure modes and the non-homogeneity of materials. The focus of this study is to obtain the force-displacement and moment-curvature behaviour of un-cracked and cracked reinforced concrete beams both in the linear and non-linear regions under static loading...

Incorporating recycled plastic waste in concrete manufacturing is one of the most ecologically and economically sustainable solutions for the rapid trends of annual plastic disposal and natural resource depletion worldwide. This paper comprehensively reviews the literature on engineering performance of recycled high-density polyethylene (HDPE) inco...

Earthquake induced steel structural failures are prevalent due to the high lateral forces applied to the structures resulting in excessive sway and more importantly ultra-low cycle fatigue of structural members. Even though lateral load resisting systems such as concentrically braced frames are installed to the moment resisting frames, ultra-low cy...

Currently, there is an increasing demand for rail transport from a growing and urbanizing population worldwide as it is a resource-efficient transport system. Moreover, its popularity among people is due to safety, reliability and economic profit. The rail track system consists of rails, fastening systems, sleepers, ballast, sub-ballast and subgrad...

This paper explores the procedure of selecting the best-fitted hyper-elastic material model to describe the mechanical behavior of filled vulcanized rubber-based products, by using nonlinear 3D numerical simulation. Constitutive relationships of these hyper-elastic material models are represented by the strain-energy density functions with the form...

Global human population continues to boom which consequently necessitates the provision for more buildings. Predominantly in developing countries, these buildings, built to accommodate the influx of more people comply with local and national building laws and regulations which have been outdated and do not resist to natural hazards and rapidly chan...

Regardless of the country, communities are highly vulnerable and exposed to disasters induced by natural hazards. There is a number of disaster risk management mechanisms in place to mitigate and address disasters. A question unanswered regarding the disaster risk management mechanisms is why the damage and destruction due to disasters are not gett...

Railway transportation is becoming popular with the growing demand and the numerous advantages of the presence of high-speed trains in many countries. In spite of its advantages, acceleration of track deterioration due to heavier loads and higher speeds is one of the major technical challenges in its development. Under repetitive train loads, the d...

Understanding causes for damages of existing structures is essential for proper damage assessment, repair and retrofitting of those structures. Further, this helps the preservation and renovation of historic and other buildings for a sustainable world. Numerical modeling using finite element modeling techniques is extensively used to model and anal...

Steel concentrically braced frames (CBF) are commonly used in the current construction industry due to its ability to dissipate input seismic energy effectively during extreme earthquake loadings as a result of global buckling phenomena of braces deliberately designed to buckle in compression. Even though this global buckling is favorable to CBF, l...

Numerical modeling has been extensively used to model and analyze masonry structures. However, correctly predicting the nonlinear behavior of masonry walls is a challenging task. Further, the level of accuracy of a numerical model owns huge computational time and cost, hence, non-feasible for day to day engineering applications. Therefore, studying...

In soil-structure interaction problems, both the superstructure and the subgrade must be analyzed together in order to determine the overall behaviour accurately. In geotechnical engineering problems, software with advanced soil models is often used to represent the complex soil characteristics. However, merging such a model with the superstructure...

Most of the high-rise buildings in the modern era are irregular in shape due to architectural and aesthetic requirements. But the performance of such buildings during an earthquake varies with the degree of irregularity. According to past studies, the degree of irregularity can be quantified using the parameters based on the geometric configuration...

Purpose Even though Sri Lanka has established Early Warning (EW) mechanisms and Evacuation Procedures (EP) for the communities affected by the coastal disasters, there are several gaps, which hinder effective mechanisms in operation of disaster management practices. These gaps affect both the vulnerable communities and relevant authorities involved...

Purpose This study aims to evaluate the coastal disaster resilience and the disaster management framework of Sri Lanka, by conducting a case study in a few coastal areas in the district of Matara which were majorly affected in 2004 by the Indian Ocean Tsunami. Although it has been 15 years since the disaster struck the country, Sri Lanka is still s...

Disaster Management mechanisms are made up with various elements. Governing bodies, Monitoring institutions, Warning disseminations institutions, External organizations, volunteers, affected community are some of the common elements in a disaster management mechanism. The mechanism uses different level of contribution from each of the element in su...

Sri Lanka is a tropical island in the Indian Ocean which has suffered from various disasters in the recent past. Flood events which occurred in the last three consecutive years clearly shows that the country is affected from climate change. During a disaster event, evacuation of vulnerable and affected communities is necessary to reduce the number...

Coastal hazards taken place all over the world have ended up with major devastations such as loss of life, property damage and environmental degradation more often. Sri Lanka, being an island in the Indian ocean is much vulnerable to coastal hazards; the unprecedented human disaster that caused by the Asian Tsunami was one of the worst examples. Pr...

Multi Hazard Early Warning Systems (MHEWS) issue warnings to help communities safely evacuate from hazardous areas. Studies showed that the response of coastal communities to warnings issued by the existing MHEW system in Asian countries including Sri Lanka is insufficient. In this study, the current context and gaps of MHEW system related to the “...

Sri Lanka, Myanmar and Maldives are few Asian countries, vulnerable to many natural hazards such as Tsunami, earthquakes, landslides, floods, cyclones, storm surges and droughts. Sea level rise and coastal erosion are another two major coastal hazards, identified as slow processes which can cause severe vulnerability among coastal communities in lo...

Emergency Response Stage actions activate immediately after the disaster event or when an emergency event is imminent and continue until the beginning of the recovery stage. During this stage, there is a necessity of accessing and sharing of disaster-related information related to affected communities and infrastructure immediately. Therefore, the...

This paper is based on data collected from the 2004 Tsunami disaster event and analyses the availability of Early Warning Systems in Sri Lanka and Myanmar after 15 years. An evaluation framework in the form of questionnaire survey was developed through a thorough literature review and studying the existing frameworks of both countries. Same questio...

This is based on data collected from the 2004 Tsunami disaster event and analyses the availability of Early Warning Systems in Sri Lanka and Myanmar after 15 years. An evaluation framework in the form of questionnaire survey was developed through a thorough literature review and studying the existing frameworks of both countries. Same questionnaire...

Abstract: A measurement of the resistance to localized plastic deformation induced by mechanical indentation is known as hardness. Hardness is mainly dependent on ductility, elastic stiffness, plasticity, residual strain, strength, toughness, and viscosity of the material. The indentation test can be carried out in macro (10^−3), micro (10^−6), and...

As metals are essential engineering materials, a knowledge of mechanical and fatigue properties of metals used in civil engineering structures is important. This Paper presents mechanical and fatigue properties and, the crack propagation and plasticity behaviour of metals such as wrought iron and mild steel used in old civil engineering structures...

A R T I C L E I N F O Keywords: Force based finite element formulation Axial-moment-shear interaction Nonlinear static response Planar reinforced concrete walls and frames A B S T R A C T This paper presents a novel fiber force-based finite element to predict the nonlinear static response of reinforced concrete frame/wall structures incorporating t...

This paper presents a novel fiber force-based finite element to predict the nonlinear static response of reinforced concrete frame/wall structures incorporating the axial force – bending moment – shear force interaction. The proposed formulation is especially suited for short elements with low span to depth ratio, where shear dominant behavior can...

Hardness is a characteristic of a material, not a fundamental physical property. It is defined as the resistance to indentation, and it is determined by measuring the permanent depth of the indentation. The resistance of a material to deformation, indentation, or penetration by means such as abrasion, drilling, impact, scratching, or wear is measur...

Predicting the failure of notched steel elements, which are subjected to low cycle loading is an essential task. The aim of the present study is to review the relationships between crack tip blunting and ductility of steel. The research procedure consists of three approaches: experimental approach, analytical approach and numerical approach. In fra...

This research is carried out to evaluate important community resilience aspects of coastal districts in Sri Lanka and to provide suitable recommendations to strengthen them. After carrying out an indepth literature survey and interviewing key personnel who are involved in the field of Disaster Management and Disaster Risk Reduction, existing status...

In this study, a new method is proposed to predict the residual strain of steel using Brinell Hardness Number (BHN). This method is developed using numerical simulations of the macro-indentation test. The proposed method is simple and efficient compared to present expensive and complicated residual strain detecting techniques. Detecting the residua...

This animation explains how to induces residual strain prior to the indentation simulation.

This data is for the specimen with proper mesh size to do the indentation simulations using ABAQUS software

Detecting the residual strain of materials of damaged civil structures is a key step of the structural damage assessment process. Metals which are existing in civil structures, always have internal strains due to fabrication, treatment processes and different types of loading conditions. Residual strains should be prevented or kept as low as possib...

Steel reinforcement bars are an important part in reinforced concrete structures. Mechanical properties such as yield strength, tensile strength and elongation are the most important parameters of steel reinforcement bars for structural designs. The variation of these parameters causes a variation in the load carrying capacities of them. Therefore,...

Detecting mechanical properties of materials of damaged civil structures is a key item of the structural damage assessment process. At present, we need to conduct series of laboratory tests to obtain a set of material properties of a target material sample. It is difficult to find a single test that can be used to detect the most important material...

Rolling contact fatigue is one of the main reasons for failures of rail girders and due to many unsolved problems this is an important research area. The present research was carried to study a procedure to assess the rolling contact fatigue life of rail girders using numerical methods and stress – life approach. In the present study, a three dime...

Characteristic strength of steel reinforcement is the material parameter most needed for reinforced concrete designs. According to Eurocode 2 (EN 1992–1–1: 2004), the characteristic yield strength of steel reinforcement (fyk) should be within the range from 400 MPa to 600 MPa and the design yield strength (fyd) should be derived based on fyk. Euroc...

Detecting mechanical properties of materials of damaged civil structures is a key item of the structural damage assessment process. At present, we need to conduct series of laboratory tests to obtain a set of material properties of a target material sample. It is difficult to find a single test that can be used to detected the most important materi...

For earthquake disaster estimation of an urban area, three-dimensional (3D) numerical simulation for the seismic response of various structures is an alternative of the current estimation that uses empirical relations of structural damage probability for an estimated ground motion index. We need to focus on developing a more rational damage estimat...

This paper presents development of a consistent mass-spring model (CMSM) of a complexed Nuclear Containment Building (NCB) based on the meta-modeling theory which allocates structural mechanics as mathematical approximation of continuum mechanics. This theory solves the same physical problem using different mathematical approximations to keep consi...

Most of the metal bridges that were built over 100 years ago are still in use in Sri Lanka. To ensure the safety of these bridges as well as their users, condition assessment of these old structures becomes essential. The details of these bridges such as their mechanical and fatigue properties and the types of materials used in these bridges are ve...

It is widely accepted that Climate Change is mainly the result of unsustainable development that cause environmental pollution. Unsustainable development activities are a major contributor to all the environmental problems the world is experiencing. In the construction boom that is happening in Sri Lanka, the dearth of professionals with a sound kn...

Smart initial guess of Conjugate Gradient (CG) method for solid finite element simulation is developed by using the meta-modeling based finite element solution conversion method. The key feature of this solution conversion method is the rigorousness; the meta-modeling ensures that the most appropriate structural or solid element solution is the one...

Physics-based initial guess of Conjugate Gradient (CG) method for solid element analysis is proposed by using the meta-modeling theory which allocates structural mechanics as a mathematical approximation of continuum mechanics. Based on the metamodeling theory, the finite element analysis can be readily classified as the solid element analysis whic...

Metal bridges were introduced to Sri Lanka in the 19th century with the development of the road network and the railways. Most of these metal bridges are still in use. However, the collapse of several old iron and steel road bridges has been reported in the recent past highlighting the need for assessing these old bridges in the country. The usual...

A quality assessment procedure of automatically constructed 3D solid bridge structure models for seismic response analysis is proposed by using a set of consistent low fidelity models. The consistency of low fidelity models is guaranteed according to the meta-modeling theory which allocates structural mechanics as mathematical approximation of cont...

In this study, an improved Consistent Mass-Spring Model (CMSM) is developed based on the meta-modeling theory which rigorously allocates structural mechanics as a mathematical approximation of continuum mechanics. The proposed CMSM can improve the accuracy of current CMSM by incorporating higher dynamic modes of a target structure. The agreement of...

Numerous studies have been carried out throughout the world for understanding fatigue, assessing fatigue damage and determining the fatigue life. The Department of Civil Engineering, Faculty of Engineering of University of Peradeniya (UOP) has conducted research on fatigue since 1990s. Some of the work of UOP is collaborative research with other le...

Rehabilitation of damaged bridges may be more beneficial than building new bridges. However, proper methods are necessary to assess the level of damages and to verify the fitness of such bridges for further use. In the assessment, there are two important criteria to consider. One is the amount of damage due to fatigue caused by usual past vehicle l...

The focus of this book is on damage assessment and fatigue life evaluation of steel structures and components using the S–N approach. The main study areas included in this book are, very high cycle fatigue (VHCF), full range S–N curves, nondestructive methods for developing full range S–N curves, effects of corrosion in full range S–N curves and fa...