Papers by Dr. CEng. A. B. M. Saiful Islam
Advanced Science Letters, 2012
In recent decades, oil and gas exploration technology has moved towards the offshore deep-water d... more In recent decades, oil and gas exploration technology has moved towards the offshore deep-water deposits. Conventional fixed jacket type platforms and bottom supported compliant platforms are found to be inefficient for exploring these resources. Floating Spar platform is suitable alternative in deep water regions. The present study performs coupled analysis of integrated Spar platform with full hull cylinder. This mathematical model incorporates almost all the major nonlinearities. Time domain analysis is done adopting an automatic Newmark-β time integration technique. Airy's wave theory is used for calculating for wave kinematics. Wave induced spar hull motion in surge, heave and pitch directions along with maximum tension in mooring line has been assessed for extreme wave height condition in 1018 m water depth.
Structures are subjected to time varying-forces due to earthquakes which in turn produce timedepe... more Structures are subjected to time varying-forces due to earthquakes which in turn produce timedependent displacements and stresses within the structures. From a design stance, only the maximum values of displacement and stress are of interest. For survival, the structure must withstand the peak value whenever that may occur. Therefore, knowing the peak values is of utmost important and this information is made available in the form of response spectra. In this study, effort has been made to generate response spectra which may be directly used in the dynamic analysis of structures in Dhaka. As there is a deficiency in apposite earthquake data at Bangladesh especially for Dhaka region, time history of Dhaka Earthquake was at first generated from recently occurred nearby earthquake. Consequently following detailed procedure response spectrum is developed. As response spectrum for a given earthquake is quite irregular and has a number of peaks and valleys, statistical approach has been adopted to construct a smoothed response spectrum to make it suitable for design. The engendered response spectrum has been evaluated with the well-known code specified response spectrum and introduces as acceptable. Therefore, the research reveals a design 'response spectrum' for Dhaka earthquake for the detail dynamic analysis ensuring as competent data for seismic design of structures.
This paper presents an intensive structural survey work on an industrial heritage structure. This... more This paper presents an intensive structural survey work on an industrial heritage structure. This study identified the decay mechanism and material characteristics of the historic structure, including material homogeneity, material strength, structural failures with crack pattern, and deteriorated surface. The damages in the building include decay in timber and stones, dampness problem and incompatible structural assemblage. The lack of a long-term maintenance is one of the potential causes which aggravate the decay mechanism. The findings permitted to appraise the structural safety and to depict some recommendations for better treatment of the structural cracks to restore this industrial heritage structure. These proposals would be useful in the conservation management plan of the city.
Nature, Sep 1, 1989
Britons and 45 per cent of Americans ... were able to state correctly both that the Earth goes ro... more Britons and 45 per cent of Americans ... were able to state correctly both that the Earth goes round the Sun and that it takes a year to do so". They clearly implied that the 30 per cent of Britons who responded that the Sun goes round the Earth are mistaken, and they actually stated that "most of the public appear not to have caught up with Nicholas Copernicus and Galileo Galilei". But look what Albert Einstein and Leopold Infeld wrote in their book The Evolution of Physics (Cambridge University Press, 1938, p. 224): Can we formulate physical laws so that they are valid for all coordinate systems (cs), not only those moving uniformly, but also those moving quite arbitrarily , relative to each other? If this can be done, our difficulties will be over. We shall then be able to apply the Jaws of nature to any cs. The struggle, so violent in the early days of science, between the views of Ptolemy and Copernicus would then be quite meaning-Jess. Either cs could be used with equal justification. The two sentences, "the sun is at rest and the earth moves", or "the sun moves and the earth is at rest" , would simply mean two different conventions concerning two different cs. Could we build a real relativistic physics valid in all cs; a physics in which there would be no place for absolute, but only for relative motion? This is indeed possible! This important lengthy passage is quoted in full lest the incredulous reader might not trust this writer's word. Most of the public may not have caught up with Copernicus and Galilei, but it appears that most of the professors have not caught up with Einstein. Should not the public expect professors of the public understanding of science to be acquainted with the most basic facts of science before they complain that most of the public are ignorant of scientific matters?
Buildings
The seismic hazard of vulnerable regions warrants the investigation of new technologies, such as ... more The seismic hazard of vulnerable regions warrants the investigation of new technologies, such as base level isolation by lead rubber bearing (LRB) devices, that can help to mitigate structural damage on seismic prone buildings. The behavior adopting such technologies can be dynamically observed in simulated environments and thus serves as a valuable metric for their feasibility. LRB base isolators were incorporated into the design of 16 model buildings to better understand how they affected a building’s seismic response while also providing information on the structural parameters. A total of 12 different types of bearing systems were tested in base isolated (BI) buildings against conventional fixed-base (FB) isolated buildings. The system of each model high-rise building was represented by the finite element package. Static as well as dynamic analysis were conducted using response spectrum analysis (RSA) based on the seismic excitation to determine the influence of the model type i...
Structural Engineering and Mechanics, 2015
Upgrading or strengthening of existing reinforced concrete (RC) infrastructure is an emerging dem... more Upgrading or strengthening of existing reinforced concrete (RC) infrastructure is an emerging demand nowadays. Near Surface Mounted (NSM) technique is very promising approach for flexural strengthening of RC members. However, premature failure such as concrete cover separation failure have been a main concern in utilizing this technique. In this study, U-wrap end anchorage with carbon fiber reinforced polymer (CFRP) fabrics is proposed to eliminate the concrete cover separation failure. Experimental programs were conducted to the consequence of U-wrap end anchorage on the flexurally strengthened RC beams with NSM-steel. A total of eight RC rectangular beam specimens were tested. One specimen was kept unstrengthened as a reference; three specimens were strengthened with NSM-steel bars and the remaining four specimens were strengthened with NSM-steel bars and U-wrap end anchorage using CFRP fabrics. A 3D non-linear finite element model (FEM) was developed to simulate the flexural response of the tested specimens. It is revealed that NSM-steel (with and without end-anchors) significantly improved the flexural strength; moreover decreased deflection and strains compared with reference specimen. Furthermore, NSM-steel with end anchorage strengthened specimens revealed the greater flexural strength and improve failure modes (premature to flexure) compared with the NSM-steel without end anchorage specimens. The results also ensured that the U-wrap end anchorage completely eliminate the concrete cover separation failure.
Science of Advanced Materials, 2016
Polymers, 2016
Existing structural components require strengthening after a certain period of time due to increa... more Existing structural components require strengthening after a certain period of time due to increases in service loads, errors in design, mechanical damage, and the need to extend the service period. Externally-bonded reinforcement (EBR) and near-surface mounted (NSM) reinforcement are two preferred strengthening approach. This paper presents a NSM technique incorporating NSM composites, namely steel and carbon fiber-reinforced polymer (CFRP) bars, as reinforcement. Experimental and analytical studies carried out to explore the performance of reinforced concrete (RC) members strengthened with the NSM composites. Analytical models were developed in predicting the maximum crack spacing and width, concrete cover separation failure loads, and deflection. A four-point bending test was applied on beams strengthened with different types and ratios of NSM reinforcement. The failure characteristics, yield, and ultimate capacities, deflection, strain, and cracking behavior of the beams were evaluated based on the experimental output. The test results indicate an increase in the cracking load of 69% and an increase in the ultimate load of 92% compared with the control beam. The predicted result from the analytical model shows good agreement with the experimental result, which ensures the competent implementation of the present NSM-steel and CFRP technique.
Seismic isolation in buildings to be a practical reality: Behavior of structure and installation ... more Seismic isolation in buildings to be a practical reality: Behavior of structure and installation technique
Journal of Civil Engineering and Management, 2014
Parallel computing briskly diminishes computation time through simultaneous use of multiple compu... more Parallel computing briskly diminishes computation time through simultaneous use of multiple computing resources. In this research, parallel computing techniques have been developed to parallelize a program for obtaining a response of single degree of freedom (SDOF) structure under earthquake loading. The study uses Distributed Memory Processors (DMP) hardware architecture and Message Passing Interface (MPI) compilers directives to parallelize the program. The program is made parallel by domain decomposition. Concurrency in the program is created by dividing the program into two parts to run on different computers, calculating forced response and free response of the first half and the second half. Parallel framework successfully creates concurrency and finds structural responses in significant lesser time than sequential programs.
The present study investigates the relationship between the transmission of COVID-19 infections a... more The present study investigates the relationship between the transmission of COVID-19 infections and climate indicators in Dhaka City, Bangladesh, using coronavirus infections data available from the Institute of Epidemiology, Disease Control and Research (IEDCR), Bangladesh. The Spearman-ranked correlation test was carried out to study the association of seven climate indicators, including humidity, air quality, minimum temperature, precipitation, maximum temperature, mean temperature and wind speed with the COVID-19 outbreak in Dhaka City, Bangladesh. The study found that, among the seven indicators, only three indicators (air quality, minimum temperature and average temperature) have a significant relationship with new COVID-19 cases. The results of this paper will give health regulators and policymakers valuable information to lessen the COVID-19 infection in Dhaka and other countries around the world.
IIUM Engineering Journal
Adopting suitable seismic protection techniques is presently a foremost concern worldwide and has... more Adopting suitable seismic protection techniques is presently a foremost concern worldwide and has become a governing principle in the growing construction industry globally. Thus, a rapid upsurge in infrastructure development in seismic-prone areas requires proper treatment for building structures. Therefore, the aim of the study is to incorporate a rubber bearing isolation device in a building base in order to diminish the seismic effect on the superstructure. The changes of structural parameters and responses of fixed-based buildings for applying High Damping Rubber Bearing (HDRB) are investigated under site-specific ground excitation. Twenty representative buildings have been used to examine the responses employing four types of HDRB systems. The study reveals that the HDRB makes the structure more flexible, offering reduced structural responses. The introduction of HDRB may help to decrease floor moment by 31~55%, which can allow the structures to withstand comparatively high se...
Revista de la construcción
Significantly growing construction in the earthquake vulnerable regions needs appropriate handlin... more Significantly growing construction in the earthquake vulnerable regions needs appropriate handling of seismic prone buildings. Insertion of high damping rubber bearing (HDRB) at the building base might be an attractive option for structural safety and economy. This study deals with incorporation of HDRB device in building base and focus on the change of structural behavior for its different categories. Structural responses of base isolated (BI) buildings under site-specific seismic excitation are analyzed. The superstructure of multistoried buildings is represented by a finite element (FE) model comprising multi-degree of freedom. The structural analyses involve the BI as well as fixed base (FB) buildings. The commercial finite element packages SAP 2000 has been used to determine the variation in structural responses performing static and dynamic analyses. Twenty prototype building frames are modelled considering four HDRB categories. The HDRB is found to make the buildings more flexible reducing the seismic responses. The increased natural period leads more importance of building flexibility effects and so the horizontal shift of superstructure increases. The story shear reduces significantly and eventually the reduced overturning moment indicates that the forces are highly overestimated if the bearing is not employed. The acceleration profile presents good agreement with the isolation strategy. Without bearing, story accelerations will be largely glorified. To lessen corresponding story shears and story accelerations HDRB can be chosen as per the specifications and necessities. Such HDRB isolated buildings can withstand rather high seismic tremors in a safe and efficient manner due to radical reduction of story responses and good structural flexibility.
IIUM Engineering Journal
The performance of high strength structural lightweight concrete (LWC) using the palm wastes, oil... more The performance of high strength structural lightweight concrete (LWC) using the palm wastes, oil palm shell (OPS) as well as palm oil clinker (POC) has been reported. Existing literatures used either OPS or POC individually for production of LWC. Each concept has their own advantages-disadvantages. In this study, both OPS and POC have been put together as coarse aggregate on the way to see the improvement of mechanical properties of waste based LWC. To achieve this purpose, regular coarse aggregate has been fully replaced by OPS and POC in the concrete. This structural grade lightweight concrete is named as palm shell and clinker concrete (PSCC). Attempts have been made with the series of OPS and POC mixture aimed at identifying for better performance. The quantity of OPS and POC mix has been varied as 30%, 40%, 50%, 60% and 70%. Mechanical properties of PSCC like density, workability, compressive strength at different ages, flexural strength, splitting tensile strength as well as ...
Revista de la construcción, 2016
Due to environmental issues, the use of waste materials in concrete is gaining popularity. Waste ... more Due to environmental issues, the use of waste materials in concrete is gaining popularity. Waste materials, such as oil palm shell (OPS) and palm oil clinker (POC) from the Malaysian palm oil industry are being used in various researches to produce lightweight concrete. Concrete containing only OPS shows more ductility and low compressive strength, while POC concrete shows less ductility but high compressive strength. The combination of OPS and POC may show improved compressive strength and ductility behavior. In this experimental study, the normal coarse aggregate is replaced by a mixture of OPS and POC aggregates in the lightweight concrete. The proportion of OPS and POC in the concrete mix varies from 40% to 70%. The results indicate that if a mixture of OPS and POC aggregate in producing lightweight concrete, better performance regarding compressive strength and ductility can be achieved. Furthermore, through the utilization of waste materials, the proposed lightweight concrete will help to mitigate the negative impact on the environment.
Earthquakes and Structures, 2015
Revista de la construcción, 2016
This paper presents the experimental behavior of reinforcement concrete beams strengthened with n... more This paper presents the experimental behavior of reinforcement concrete beams strengthened with near surface mounted (NSM) steel bar. Several researchers have used NSM fiber reinforced polymer (FPR) bar or strip for strengthening reinforced concrete beams. Though FRP has a number advantages like high strength, light weight and corrosion resistance it doesn't show any ductile behavior, still highly expensive and not easily available in market. On the other hand, steel bar is less expensive, readily available in the market and shows good ductility. In order to get rapid and economic strengthening solution, strengthening with near surface mounted steel bar may become a potential alternative to retrofit reinforced concrete members. Therefore, the main purpose of this paper to investigate the experimental behavior of reinforced concrete beam strengthened with near surface mounted steel bar. Seven full-size beams (one control beams and six strengthened beams) were tested. Steel bars were used for strengthening. The failure load, mode of failure, deflection, and strain behavior are discussed. The study reveals that the near surface mounted technique with steel bars and cement mortar is the most economical strengthening solution to increase the flexural performance of RC beams.
Journal of Engineering and Technology Research, Apr 30, 2011
Although a great deal of research has been carried out regarding seismic isolation, there is a la... more Although a great deal of research has been carried out regarding seismic isolation, there is a lack of proper research on its behavior and implementing technique in low to medium seismic region. The basic intention of seismic protection systems is to decouple the building structure from the damaging components of the earthquake input motion, that is, to prevent the superstructure of the building from absorbing the earthquake energy. This paper reviews a number of articles on base isolation incorporation in building structure. Lead rubber bearing (LRB), high damping rubber bearing (HDRB), friction pendulum system (FPS) have been critically explored. This study also addressed the detail cram on isolation system, properties, characteristics of various device categories, recognition along with its effect on building structures. Meticulous schoolwork has also been accomplished about installation technique for various site stipulations. The entire superstructure is supported on discrete isolators whose dynamic characteristics are chosen to uncouple the ground motion. Displacement and yielding are concentrated at the level of the isolation devices, and the superstructure behaves very much like a rigid body. Rigorous reckoning illustrated the isolation system as very innovative and suitable in buildings to withstand the seismic lateral forces and also contributed to safety ensuring flexibility of structures.
Science of Advanced Materials, 2016
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Papers by Dr. CEng. A. B. M. Saiful Islam