H. A. D. Samith Buddika

• Doctor of Philosophy
• Senior Lecturer at University of Peradeniya

A method to accurately calculate seismic shear forces in post-tensioned hybrid (PH) precast concrete walls under risk-targeted maximum considered earthquake (MCER) level ground motions is essential, to avoid unexpected damage or possibly failure. Although extensive research on seismic performance evaluation of PH precast concrete walls has been car...

Recently, machine learning-based prediction models have gained considerable popularity in predicting the compressive strength of concrete using results from Non-Destructive Testing (NDT) methods. This research considers NDT results from Rebound Hammer (RH) and Ultrasonic Pulse Velocity (UPV) tests for concrete samples with different concrete grades...

In Sri Lanka, a considerable portion of the rural population has limited access to paved roads, with many roads in poor condition or unpaved, particularly impacting rural populations during rainy seasons, which is believed to constrain rural economic growth opportunities. There is a recent trend that rural roads are paved using concrete (i.e. rigid...

Surface crack detection is an integral part of infrastructure health surveys. This work presents a transformative shift towards rapid and reliable data collection capabilities, dramatically reducing the time spent on inspecting infrastructures. Two unmanned aerial vehicles (UAVs) were deployed, enabling the capturing of images simultaneously for ef...

Biochar is a well-known sustainable and effective additive used in mortar/ concrete to improve its mechanical properties. However, its potential to improve the impact resistance of concrete is still unexplored. This paper investigates biochar's effectiveness in improving the strength and impact performance of alkali-activated slag concrete (AASC)....

Biochar is a well‐known sustainable and effective additive used in mortar/concrete to improve its mechanical properties. However, its potential to improve the impact resistance of concrete is still unexplored. This paper investigates biochar's effectiveness in improving the strength and impact performance of alkali‐activated slag concrete (AASC). F...

The integrity of steel structures is significantly impacted by corrosion, necessitating precise assessment methods. This study introduces an innovative approach using Multi-Spectral Imaging (MSI) and Spectral Unmixing (SU) to analyze the relative composition of corrosion phases such as Lepidocrocite, Magnetite, Goethite, and Hematite on steel sampl...

This study gives a detailed comparative investigation of bamboo's mechanical properties, analyzing the relationship between information acquired from the literature and experimental data. Bamboo, known for its ecological sustainability and mechanical adaptability, has acquired widespread acceptance in a variety of technical applications. The goal o...

Different types of fibers are used in building construction to enhance strength and to reduce cracks in structural and non-structural concrete components. Among the fiber cement (FC)composites, FC thin sheets are extensively used as a building material, mainly in ceilings, siding, and flooring. FC thin sheets are lightweight and demonstrate a high...

Abstract Surface crack detection is an integral part of infrastructure health surveys. This work presents a transformative shift towards rapid and reliable data collection capabilities dramati-cally reducing the time spent in inspecting infrastructures. Two Unmanned Aerial Vehicles (UAVs) in a coordinated swarm setting were deployed enabling the ca...

Stupa structures in Sri Lanka are regarded as world heritage sites with rich archaeological and artistic value, some nearing a lifetime of almost 2 millennia. Conservation and management efforts are currently hindered due to the lack of practice of modern Building Information Modelling (BIM) techniques. Recently, Digital Twins (DT) as a tool for Hi...

Bamboo is a natural biodegradable material used as a strength-bearing material that operates for system works, formwork supporting stands, structural members in low-rise houses, props, framing, bridges, laminated flooring, facades, walls, roofs, and trusses. Over recent years, there has been an increased demand for bamboo, considering sustainable c...

In the past, asbestos siding, roofing, and ceiling sheets became more popular than conventional materials due to their high strength-to-weight ratio, durability, and low cost. However, it was later identified that most types of asbestos are carcinogenic and are responsible for major lethal diseases. In terms of developing a substitute for asbestos,...

This research aimed at assessing the feasibility of activating biochar and ground granulated blast furnace slag(GGBS) combination using a blend of sodium carbonate and sodium hydroxide as the alkaline activator as apotential sustainable construction material. Taguchi Orthogonal experimental design was used to optimise themix proportions considering...

During past decades, Asbestos roofing and ceiling sheets became more popular than traditional roofing materials due to their light weight, strength, and low cost. However, later it was identified that most types of asbestos are carcinogenic and are responsible for four major lethal diseases. The World Health Organization reports that as consequence...

This research aimed at assessing the feasibility of activating biochar and ground granulated blast furnace slag (GGBS) combination using a blend of sodium carbonate and sodium hydroxide as the alkaline activator as a potential sustainable construction material. Taguchi Orthogonal experimental design was used to optimise the mix proportions consider...

Stupa structures in Sri Lanka are regarded as world heritage sites with rich ar-chaeological and artistic value some nearing a lifetime of almost 2 millennia. Conservation and, management efforts currently hindered due to the lack of practice of modern building information modelling techniques. Digital Twins as tool for Historic Building Informatio...

Minarets are one of the most important architectural and cultural inheritances for Muslims and Christians in the world. They are slender tower-type structures constructed generally as adjacent to the main body of the mosques at the corner side or built individually. A large number of traditional cylindrical reinforced concrete minarets collapsed or...

Reinforced concrete bridges are the most commonly found bridges in Sri Lanka. Although Sri Lanka has been a less seismic vulnerable country in the past, recent development of a new plate boundary towards the South Eastern coast of Sri Lanka has made Sri Lanka a moderate earthquake prone country. Many researches have been conducted for the seismic p...

The structural behavior of bridges can be significantly affected by moving vehicle loads associated with roadway traffic. This response is evaluated in the bridges mid and edge lanes. This entire analytical procedure is based on finite element analysis. The beam element was used to create a finite element model for analyzing the simply supported in...

Code-based methods can only be used to determine the wind loading on single-plate billboards in the normal wind direction. No simplified methods are available to estimate the drag force coefficient for single-plate and two-plate billboards for various aspect ratios, clearance ratios and wind attack angles. Using the experimental types of research o...

Tsunami bore is a steep, turbulent, rapidly moving Tsunami wave front that empowers objects such as shipping containers, boats, and shipwrecks that propagate ashore with a tremendous power. Once such an object collides with a near shore structure, a massive impact force is triggered due to the energy transfer. Literature reveals previous attempts o...

When considering post-earthquake serviceability, self-centering bridge structures are prominent. Instead of using post-tension technology, the use of reinforced concrete columns with low bond high strength reinforcement (LBHSR) as longitudinal reinforcement came into the discussion as to their low cost and simplicity. Here, Numerical models have be...

The wind factor becomes a major concern in designing high-rise buildings in Sri Lanka due to its vibration effect. To design a tall building in the habitability region, it is essential to calculate dynamic parameters such as the damping ratio and natural frequency of the building. However, there is no specific method to identify the damping ratio a...

Wind factor becomes a major concern in designing high-rise buildings in Sri Lanka due to its vibration effect. To design a tall building in the habitability region, it is essential to calculate dynamic parameters such as the damping ratio and natural frequency of the building. However, there is not a specific method to identify the damping ratio an...

Wind factor becomes a major concern in designing high-rise buildings in Sri Lanka due to its vibration effect. To design a tall building in the habitability region, it is essential to calculate dynamic parameters such as the damping ratio and natural frequency of the building. However, there is no specific method to identify the damping ratio and n...

Minarets are one of the most important architectural cultural inheritances. They are slender tower-type structures constructed generally as adjacent to the main body of the mosques at the corner side or built individually. A large number of traditional cylindrical reinforced concrete minarets collapsed or were heavily damaged during past earthquake...

In Sri Lanka, the demand for tall building design and construction is drastically increasing in recent years. During the wind design, the dynamic response under the habitability region and safety region is of major consideration. The natural frequency and damping of the building have a significant influence on the dynamic response and structural de...

This work is as part of India-SriLanka Joint research funded by Department of Science and Technology, Government of India and MSRT SriLanka.

In Sri Lanka, the demand for tall building design and construction is drastically increasing in recent years. Apart from small buildings, ambient forces are quite significant in the response of tall buildings. During the wind design, the dynamic response under habitability region and safety region is of major consideration. The natural frequency an...

Wireless sensor network (WSN) based SHM systems have shown significant improvement as compared to traditional wired-SHM systems in terms of cost, accuracy, and reliability of the monitoring. However, due to the resource-constrained nature of the sensor nodes, it is a challenge to process a large amount of sensed vibration data in real-time. Existin...

This paper attempts to document the root cause of the development of spalling cracks and bursting cracks at the end block anchorage zone of post-tensioned precast bridge girders in Sri Lanka. These problems are not limited to those of post-tensioned precast bridge girders, but may occur in other type of structures with similar conditions and detail...

Conventional code-based design approach can only be used for preliminary design of regular single-plate billboards for normal wind direction. Therefore, High Frequency Force Balance (HFFB) technique and Computational Fluid Dynamics (CFD) have now emerged as alternative techniques for comprehensive designs. With the many experimental researches done...

Beam-Column joint is vital in reinforced concrete structures under seismic loadings. Cyclic loading produces a progress deterioration of bond. If sufficient length of anchorage is not provided, bond-slip can be occurred. So, beam-column joint is vulnerable in the case of earthquakes. In this study, a finite element model has been implemented in com...

The communication industries have seen a tremendous increase in last few years which have resulted in installation of large number of towers to increase the coverage area and network consistency. In wireless communication network, these towers play a significant role hence failure of such structure is a major concern. Many researches have determine...

Floor vibrations induced by human walking were investigated in the study. The management of an industrial building encountered complaints of severe headache, vomiting, from its occupants in the newly built mezzanine floor. Especially some occupants complained regarding annoying or distracting vibrations in the floor. Floor vibration measurements we...

The communication industries have seen a tremendous increase in last few years which have resulted in installation of large number of towers to increase the coverage area and network consistency. In wireless communication network, these towers play a significant role hence failure of such structure is a major concern. Many researches have determine...

Concrete is the most widely using construction materials in the world as it has many advantages compared to other construction materials such as wood and steel. One of the major comparative advantage of concrete is the high thermal resistivity of concrete. Although concrete has a high thermal resistivity, the chemical and physical properties of the...

Post-tensioned rocking hybrid (PH) precast concrete walls have been developed as an alternative to cast-in-place reinforced concrete (RC) shear walls for lateral-force resisting systems in buildings located in earthquake prone regions. In PH precast concrete walls, damage at the wall base is minimized by allowing gap opening/closing at the wall-fou...

Post-tensioned rocking (PR) precast concrete walls have been developed as an alternative to cast-in-place reinforced concrete (RC) shear walls for lateral-force resisting systems in buildings located in earthquake prone regions. In PR precast concrete walls, damage at the wall base is minimized by allowing gap opening/closing at the wall-foundation...

Code-based methods and even most advanced tools such as the High-frequency Base Balanced (HFBB) data analysis have not been able to deliver accurate results in determining the effect of wind loads on high rise buildings. Moreover, the previously mentioned methods are able to deliver only limited information regarding the overall building behaviour...

Seismic performance of post-tensioned hybrid precast concrete wall-frame (PWF) buildings has been mainly studied in the past by considering the effects of far-fault (FF) ground motions. In the present study, the multi-level seismic response of PWF buildings is investigated for near-fault (NF)pulse-like ground motions. For that purpose, rigorous non...

The equivalent flag-shaped single-degree-of-freedom system used to calculate DE-level and MCER-level roof drifts of PH precast concrete walls is first described, and then validated with the results obtained using the 2D macromodel of a PH precast concrete wall. The maximum wall displacement of a PH precast concrete wall is assumed to be dominated b...

A method to accurately calculate seismic shear forces in post-tensioned hybrid (PH) precast concrete walls under risk-targeted maximum considered earthquake (MCER) level ground motions is essential to avoid unexpected damage or possibly failure. Although extensive research on seismic performance evaluation of PH precast concrete walls has been carr...

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...

Cultural heritage structures are an integral facet of the irreplaceable cultural heritage of a nation and have been constructed several hundreds and even thousands of years ago. In this paper, based on a field reconnaissance of the highly damaged areas of Kathmandu Valley and Sindhupalchowk district, damage to cultural heritage structures due to th...

Seismic performance of posttensioned hybrid precast wall systems has been mainly studied in the past without considering the interaction of the wall system with the rest of the structure. In the present study, the multilevel seismic response of posttensioned hybrid precast wall-frame (PWF) buildings is evaluated using nonlinear response history ana...

The development of new structural systems which suffer no or minor damage following a severe event was a key interest of researchers during the past few decades. Self-centering walls with alternative dissipation mechanisms were among the next generation candidates for a damage avoidance design of structures while being cost effective. However, the...