Taksiah A. Majid

Experimental Study of Hysteretic Steel Damper for Energy Dissipation Capacity

This study aims to evaluate energy absorption capacity of hysteretic steel damper for earthquake protection of structures. These types of steel dampers are fabricated from mild steel plate with different geometrical shapes on the side part, namely, straight, concave, and convex shapes. The performance of the proposed device was verified experimentally by a series of tests under increasing in-plane cyclic load. The overall test results indicated that the proposed steel dampers have similar hysteretic curves, but the specimen with convex-shaped side not only showed stable hysteretic behavior but also showed excellent energy dissipation capabilities and ductility factor. Furthermore, the load-deformation relation of these steel dampers can be decomposed into three parts, namely, skeleton curve, Bauschinger part, and elastic unloading part. The skeleton curve is commonly used to obtain the main parameters, which describe the behavior of steel damper, namely, yield strength, elastic stiffness, and postyield stiffness ratio. Moreover, the effective stiffness, effective damping ratio, cumulative plastic strain energy, and cumulative ductility factor were also derived from the results. Finally, an approximation trilinear hysteretic model was developed based on skeleton curve obtained from experimental results.

Project Management Success for Post-disaster Reconstruction Projects: International NGOs Perspectives☆

Abstract Natural disaster happened frequently around the world and caused great loss of lives and properties. Since incidents of natural disasters increase, it is crucial that NGOs and other agencies involved in reconstruction to learn as much as possible from previous projects they involved with; its successes and failures. Post-disaster reconstruction (PDR) is a complex and highly demanding process that involves a number of different and well coordinated courses of action. Therefore, it is vital that these complex activities are well planned, subject to thorough consultation. The broad objective of this research is to study the issues and challenges and investigating the success factors to determine which critical success factors are most influential in avoiding particular project failures. The goal of this research is to improve project management practice in PDR project specifically for International NGOs that participate in the phase of Post-Disaster Reconstruction. It can serve as a platform for other researchers to launch into this evolving new field.

Statistical evaluation of pre-selection criteria for industrialized building system (IBS)

AbstractThe Malaysian government has endorsed the use of an industrialized building system (IBS) in domestic projects. These have shifted the focus of the nations construction industry towards mass production and modular products. A proper study on site selection criteria for new IBS precast manufacturing sites has now become essential. The preliminary study in this research determines the IBS precast manufacturing site selection criteria from literature reviews. Questionnaires pertaining to IBS acceptance and preference criteria were send to manufacturers, policymakers, academicians and contractors. The outcome analyses the respondents’ view towards 15 site selection criteria. The result from the ANOVA statistical test indicates that most respondents agreed with the selected criteria except political and regulation criteria, urban requirement criteria, and personal criteria. However, there is a significant difference within the opinions of the contractors and manufacturers sector. Likewise, the mean ran...

The Industrialized Building System (IBS) Survey Report 2008--Educating the Malaysian Construction Industry

The IBS Survey report 2008 continues a practice that began in 2003. The first report was published in 2003 followed by in 2005 and recently in 2008. It records recent trends in selected areas that reflect the Malaysias achievement of IBS usage in the building construction industry. Due to dynamic economic and technological changes, IBS usage reports have been increasingly important. The design of quantitative survey in IBS acceptance questionnaire design is based on the Technology Acceptance Model (TAM) and verified the reliability of questionnaire design by alpha-Cronbach. The result of alpha-Cronbach on IBS acceptance questionnaire is 0.787 which is round out to 0.8. The re-arrangements of items in the questionnaire design and the validity of the questionnaire has been checked and found to be valid. The awareness of using IBS in the construction industry in Malaysia has been successfully measured based on the IBS actual use, perceived ease of IBS use and perceived IBS usefulness with a scoring of alpha-Cronbach 0.861, 0.744 and 0.853 respectively.

Grid Computing for Disaster Mitigation

The infamous 2004 Andaman tsunami has highlighted the need to be prepared and to be resilient to such disasters. Further, recent episodes of infectious disease epidemics worldwide underline the urgency to control and manage infectious diseases. Universiti Sains Malaysia (USM) has recently formed the Disaster Research Nexus (DRN) within the School of Civil Engineering to spearhead research and development in natural disaster mitigation programs to mitigate the adverse effects of natural disasters. This paper presents a brief exposition on the aspirations of DRN towards achieving resilience in communities affected by these natural disasters. A brief review of the simulations of the 2004 Andaman tsunami, with grid application is presented. Finally, the application of grid technology in large scale simulations of disease transmission dynamics is discussed.

Nonstructural Damages of Reinforced Concrete Buildings Due to 2015 Ranau Earthquake

On 15th June 2016 a moderate earthquake with magnitude Mw5.9 was occurred in Sabah, Malaysia. Specifically, the epicentre was located at 16 km northwest of Ranau. Less than two days after the first event, a reconnaissance mission took action to investigate the damages on buildings. Since the reinforced concrete buildings in Ranau were designed based on gravity and wind load only, a lot of minor to severe damages was occurred. This paper presents the damages on the nonstructural elements of reinforced concrete buildings due to Ranau earthquake. The assessment was conducted via in-situ field investigation covering the visual observation, taking photo, and interview with local resident. Based on in-situ field investigation, there was a lot of damages occurred on the nonstructural elements like the brick walls. Such damages cannot be neglected since it can cause injury and fatality to the victims. Therefore, it can be concluded that the installation of nonstructural elements should be reviewed for the sake of safety.

Dispersion of Multi-Walled Carbon Nanotubes in Portland Cement Concrete Using Ultra-Sonication and Polycarboxylic Based Superplasticizer

The potential properties of carbon nanotube-cement based materials strongly depend on the dispersion of carbon nanotubes (CNTs) within the cement matrix and the bonding between CNTs and the hydrated cement. The homogeneous dispersion of CNTs in the cement matrix yet is one of the main challenges due to strong van der Waals forces between nanotubes. In this study, a polycarboxylic ether based superplasticizer and ultra-sonication technique was used for dispersion of multi-walled carbon nanotubes (MWCNTs). Portland cement concrete specimens with different concentrations of MWCNTs (0.04 and 0.1 % by the weight of cement), with and without the presence of superplasticizer were investigated. Compressive strength test results revealed a significant improvement in mechanical properties of sample containing 0.1 % MWCNTs and 0.2 % superplasticizer. Moreover, field emission scanning electron microscopy (FESEM) images of fractured surfaces of hardened specimens showed a good dispersion of MWCNTs within the cement matrix. This method was developed to facilitate the uniform dispersion of MWCNTs in the cementitious concrete for better reinforcement in nanoscale and mechanical properties enhancement by transfer of load between the nanotubes and matrix.

Estimation of Tsunami Force for Onshore Buildings in the Northwest Coast of Peninsular Malaysia

The northwest coast of Peninsular Malaysia had suffered various extents of structural damage and loss of 68 lives in the unprecedented 2004 Indian Ocean tsunami. Since then, the government of Malaysia concerns about the safety of civil engineering structures and human lives in coastal area. An experimental study was embarked on the formulation of tsunami force for onshore buildings in Peninsular Malaysia. Four downscaled rigid building models with various heights were subjected to probable tsunamis with three nominal wave heights and flow velocities. The wave pressures at front and back faces of building model were measured. The findings show that the front face wave pressure measured from the experiment is in good agreement with the wave pressure predicted using the equation proposed by Japanese researchers. The back face wave pressure distribution is found to be slightly higher than the hydrostatic pressure. The pressure distributions at the front and back faces were then proposed for the estimation of tsunami force on buildings in the northwest coast of Peninsular Malaysia.

Effects of Site Classification on Empirical Correlation between Shear Wave Velocity and Standard Penetration Resistance for Soils

In seismic engineering, the dynamic property of the soil is one of the most important aspects in ground response analysis. Dynamic property is significantly affected by local soil deposits. Shear wave velocity (Vs) of soil is one of the main parameters in determining the amplification factor on ground surface. It is not economically feasible to measure Vs for all sites. Therefore, a reliable empirical correlation between Vs and standard penetration resistance (Nspt) will be useful since Nspt data are easily obtainable in construction industry. This study aims to develop an empirical correlation between Vs and Nspt for all soils by considering the effect of site classification according to the Uniform Building Code. New empirical correlations for all soils are presented in this study and well compared with the previous study to evaluate prediction capability. Results show that site classification has a significant impact on the Vs estimation, and that the proposed correlations are the most appropriate for estimating the Vs profile in the studied area compared with existing correlations.

Soft storey effects on plastic hinge propagation of moment resisting reinforced concrete building subjected to Ranau earthquake

On 5th June 2015, a moderate earthquake with Mw 5.9 hit Ranau, resulted in damages of the existing nonseismically designed buildings, such that 61 buildings, including mosques, schools, hospitals and Ranau police headquarters were suffered from different level structural damages. Soft storey irregularity is one of the main reasons of the building damage. This study is to investigate the soft-story effect on the propagation path of plastic hinges RC building under seismic excitation. The plastic hinges formation and seismic performance of five moment resisting RC frames with different infill configurations are studied. The seismic performance of building is evaluated by Incremental Dynamic Analysis (IDA). Open ground soft storey structure shows the lowest seismic resistance, collapses at 0.55g pga. The maximum interstorey drift ratio (IDRmax) in soft storey buildings ranging from 0.53% to 2.96% which are far greater than bare frame ranging from 0.095% to 0.69%. The presence of infill walls creates stiffer upper stories causing moments concentrate at the soft storey, resulting the path of plastic hinge propagation is dominant at the soft storey columns. Hence, the buildings with soft storey are very susceptible under earthquake load.