bluuebunny/crossref_metadata_2025 huggingface dataset:
An Approach to Delineate Groundwater Bodies at Risk: Seawater Intrusion in Liepāja (Latvia)
Authors: Bikše J. , Retike I.
Published: September 2018

Groundwater quality in coastal areas is frequently affected by seawater intrusion as a consequence of intensive water consumption. To achieve “good chemical status” of a groundwater body according to Water Framework Directive the effects of saline or other intrusions should not be observed. Groundwater pumping in former decades has caused a significant seawater intrusion into confined aquifer in Liepāja and has led to deterioration of relatively wide coastal area of the third largest city in Latvia. However, the area affected by seawater intrusion is a small part of groundwater body F1 which overall chemical status is good. Thus, no specific management measures have been applied to explore and control seawater intrusion. A political decision was made to delineate the area affected by seawater intrusion as new groundwater body at risk- F5. This study demonstrates simple approach for delineation of groundwater bodies at risk in coastal areas. Delineation process was based on chloride concentration gradient along the well profile and gradient based buffers. Finally, the worst-case scenario was selected for delineation of boundaries.
On the use of COMSOL Multiphysics for seawater intrusion in fractured coastal aquifers
Authors: Mozafari B. , Fahs M. , Ataie-Ashtiani B. , Simmons C. T. , Younes Rafic
Published: September 2018

COMSOL Multiphysics is a comprehensive simulation software environment for a wide range of applications. COMSOL has an interactive interface that facilitates the modeling procedure and allows an easy coupling of different physical processes. The Subsurface Flow module extends the COMSOL modeling environment to applications related to fluid flow in saturated and variably saturated porous media. COMSOL is increasingly used in the investigation of geophysical, hydrogeological and environmental phenomena. The main goal of this work is to explore the ability of COMSOL for simulating seawater intrusion (SWI) in fractured coastal aquifers. Numerical modeling of such a problem is of high interest as fractured/karstic coastal aquifers are widespread and processes of SWI in the presence of fractures remains poorly understood. We set up a COSMOL model for the popular Henry problem. The accuracy of COMSOL is highlighted by comparison against the semianalytical solutions for simple homogeneous aquifers. For fractured aquifers, the performance of COSMOL is evaluated by comparison against an in-house finite element model based on the discrete fracture model and against the results of existing works. Given its versatility and flexibility, COMSOL shows promise as a tool for SWI in coastal aquifers.
Can bomb-peak tritium persist in the transition zone? A case study from the German island of Langeoog
Authors: Post V.E.A. , Houben G.J.
Published: September 2018

Tritium has been used as a tracer in hydrogeological studies to date young groundwater. It was released in massive amounts to the atmosphere by nuclear bomb testing in the 1950’s and early 1960’s. Its activity in the atmosphere peaked around 1963-1964 and has been steadily falling since then due to its half-life of 12.32 years. On the northern hemisphere, where the atmospheric tritium concentration reached much higher levels than on the southern hemisphere, elevated tritium activities in groundwater persist, and thus can still be used to identify groundwater that has recharged during the post-bomb era.
Assessing groundwater vulnerability to sea water intrusion in the coastline of the inner Puck Bay using GALDIT method
Authors: Potrykus Dawid , Gumuła-Kawęcka Anna , Jaworska-Szulc Beata , Pruszkowska-Caceres Małgorzata , Szymkiewicz Adam , Dzierzbicka-Głowacka L.
Published: September 2018

In this research, GALDIT method was used to assess seawater intrusion in the coastal aquifer of the inner Puck Bay (Southern Baltic Sea). The impact of potential sea-level rise on groundwater vulnerability for years 2081-2100 was also considered. The study area was categorized into three classes of vulnerability: low, moderate and high. The most vulnerable area is the Hel Peninsula with northern part of the Kashubian Coastland. Increased class of aquifer vulnerability is also adopted to glacial valleys. The results of this research revealed that about 18.9% of the analyzed area is highly vulnerable to seawater intrusion, 25.3% is moderately vulnerable and 55.8% is potentially at low risk. The simulated scenario of predicted sea level rise shows enlargement of high vulnerability areas.
Characterization of a regional coastal zone aquifer using an interdisciplinary approach – an example from Weser-Elbe region, Lower Saxony, Germany
Authors: Rahman Mohammad Azizur , González Eva , Wiederhold Helga , Deus Nico , Elbracht Jörg , Siemon Bernhard
Published: September 2018

In this study, interdisciplinary approaches are considered to characterize the coastal zone aquifer of the Elbe-Weser region in the North of Lower Saxony, Germany. Geological, hydrogeological, geochemical and geophysical information have been considered to analyze the current status of the aquifers. All the information collectively states that the salinity distribution in the subsurface is heterogeneous both horizontally and vertically. Early age flooding also contributed to this heterogeneity. No general classification of groundwater quality (according to some piper diagrams) could be identified. Helicopter-borne electro-magnetic data clearly show the presence of freshwater reserves below the sea near the west coast. Groundwater recharge largely happens in the moraine ridges (west side of the area) where both the surface elevation and the groundwater level are high. Consequently, submarine groundwater discharge occurs from the same place. All these information will facilitate to develop the planned density driven groundwater flow and transport model for the study area.
Modeling saltwater intrusion scenarios for a coastal aquifer at the German North Sea
Authors: Schneider A. , Zhao H. , Wolf J. , Logashenko D. , Reiter S. , Howahr M. , Eley M. , Gelleszun M. , Wiederhold H.
Published: September 2018

A 3d regional density-driven flow model of a heterogeneous aquifer system at the German North Sea Coast is set up within the joint project NAWAK (“Development of sustainable adaption strategies for the water supply and distribution infrastructure on condition of climatic and demographic change”). The development of the freshwater-saltwater interface is simulated for three climate and demographic scenarios.

Groundwater flow simulations are performed with the finite volume code d3f++ (distributed density driven flow) that has been developed with a view to the modelling of large, complex, strongly density-influenced aquifer systems over long time periods.
Laboratory Scale Investigation of Dispersion Effects on Saltwater Movement due to Cutoff Wall Installation
Authors: Takahashi Masahiro , Momii Kazuro , Luyun Roger
Published: September 2018

In the numerical investigation of saltwater transport in coastal aquifers, we need to correctly evaluate the hydrodynamic dispersion in the flow field. In this study, we focused on the role of dispersivity in the removal process of residual saltwater in a laboratory scale cutoff wall experiment. From a pulse-type fluorescent tracer injection experiment in a saturated porous media of glass beads with a mean diameter of 0.088 cm, the estimated longitudinal and transverse dispersivities were found to be 0.07 cm and 0.0025 cm, respectively. Numerical analysis of the saltwater intrusion and subsequent removal after cutoff wall installation using SEAWAT and the generated dispersivity ratio (αL/αT) of 28 reproduces well the measured salt concentration changes with time. Whereas, if a dispersivity ratio of 10 is used in the numerical simulation, transverse dispersion in the saltwater and freshwater mixing zone becomes large and the residual saltwater is removed faster than the laboratory experiment. Inversely, if 100 was used, the residual saltwater removal time took longer. The transverse dispersion is a key parameter in the mechanical dispersion of saltwater in the mixing zone after cutoff wall installation.
Neutron reflectivity for soft matter
Authors: Cousin Fabrice , Chennevière Alexis
Published: September 2018

Specular neutron reflectivity is a technique enabling the measurement of coherent neutron scattering length density profile perpendicular to the plane of a surface or interface, and thereby the profile of chemical composition. The characteristic sizes that are probed range from around 5Å up 5000 Å. It is a scattering technique that averages information over the entire surface and it is therefore not possible to obtain information on correlations in the plane of the interface. The specific properties of neutrons (possibility of tuning the contrast by isotopic substitution, negligible absorption, low energy of the incident neutrons) makes it particularly interesting in the fields of soft matter and biophysics. This course is composed of three parts describing respectively its principle, the experimental aspects (diffractometers, samples), and some scientific examples of neutron reflectometry focusing on the use of contrast variation to probe polymeric systems.
The Virtual Element Method with curved edges
Authors: Beirão da Veiga L. , Russo A. , Vacca G.
Published: September 2018

In this paper we initiate the investigation of Virtual Elements with curved faces. We consider the case of a fixed curved boundary in two dimensions, as it happens in the approximation of problems posed on a curved domain or with a curved interface. While an approximation of the domain with polygons leads, for degree of accuracy k≥2, to a sub-optimal rate of convergence, we show (both theoretically and numerically) that the proposed curved VEM lead to an optimal rate of convergence.
Investigation and Analysis of the Catastrophic Failure of an Offshore Water Injector Well
Authors: Ramasamy Ramesh
Published: September 2018

The catastrophic failure of an offshore water injector well is presented in this paper. The failure mode was determined from the final collapsed state of the conductor pipe which resulted in the surface Xmas tree and wellhead to drop vertically down onto the platform deck. Various inspections and assessments are carried out to determine the integrity of the well structure and compared against the original drilling records. Stability evaluations of the casing is also carried out to account for the loss of annular cement which resulted in loss of centralisation. The analyses conclude that various sequence of events have contributed towards the failure of this well. The lack of intermediate inspections and monitoring have resulted in uninhibited corrosion and pitting on the conductor pipe. Some considerations on the necessity of an effective inspections strategy and rationalisations of a robust integrity screening are also drawn.
Physical Modeling of Landward Scour Due to Tsunami Bore Overtopping Seawall
Authors: Maqtan Raidan , Yusuf Badronnisa , Hamzah Saiful Bahri
Published: September 2018

many of the post tsunami field surveys which conducted by researchers revealed that, the failure due to scour at the landward toe of the seawall due to overtopping of tsunami wave forms one of the important types of coastal defence structures failure and constitutes one of the biggest threats to their structural performance. This study was intended to investigates the scour profile induced by tsunami bores at the landward toe of the vertical seawall and to discuss the effects of the parameters; tide level, incident bore Froude number Fb, incident bore height Hb, overtopping flow Froude number Fo, and overtopping flow depth Ho on the maximum scour depth induced at the landward toe of the seawall. A set of laboratory experiments were conducted at National Hydraulic Research Institute of Malaysia (NAHRIM) with the tichnique of dam break to generate the bore like tsunami. The experiments showed that the initial water level upstream of the seawall has a significant effect on the scour profile and there is a strong negative relationship exists with Froude number of the incident bore and a strong positive relationship exists with Froude number of the overtopping flow depth above the crest of the seawall.
A Short Review of Submerged Breakwaters
Authors: 'Izzat Na'im Ibrahim , Shahrizal Ab Razak Mohd , Safari Mat Desa
Published: September 2018

Breakwaters are used around the globe as a mean of protection against beach erosion by reducing the height of incoming waves into smaller transmitted waves. In addition, breakwaters can efficiently be used to preserve tranquillity inside the harbour basin, to decrease the deposition of sediments that can lead to water pollution at the harbour entrances, and to be a sanctuary for marine habitats. The purpose of this study is to discuss the application of the innovative submerged breakwater globally and in Malaysia. In addition, the comparison between submerged and emerged breakwater are briefly explained to understand the distinction between these two structures. The future experiment of the newly developed breakwater in Malaysia known as WABCORE is also included in this paper where the experimental setup and expected results are discussed.
Simulation Model Pattern Distribution Sediment at Ambon Bay, Indonesia
Authors: Hatta Mukhsan Putra , Thaha Muhammad Arsyad , Lakatua Marthen P
Published: September 2018

The sedimentation occurring in the outer Ambon bay as a result of the effluent from Way Ruhu river causes the reduction the mouth of the outer Ambon Bay, so that it influences the current movement pattern and sediment distribution. This research aimed at analyzing the current movement pattern and sediment distribution pattern in the outer Ambon bay using two scenarios: with the reclamation and without reclamation. The research used the numerical model of MIKE 21DHI with modules of the hydrodynamic and mud transport. The research result indicates that the simulation current velocity with the absence of reclamation ranged from 0.0-0.4 m/s, while with the presence of the reclamation, the current velocity is slightly higher that is between 0.0 - 0.6 m/s the various velocity patterns. The sediment distribution pattern in the outer Ambon bay as the result of the effluent from the way Ruhu river follows the current movement. If the conditions leading to the tide and the highest tide, the sediment going out from way Ruhu river is pushed into the bay and vice versa, when the condition leading to the recede and lowest recede, the sediment concentration is pulled out from the bay. The suspended sediment concentration is between 0.002 kg/m3 - 0.030 kg/m3 with the various patterns. The suspended sediment concentration to the condition without reclamation is more collecting if compared with the suspended sediment concentration by the presence of the distributing reclamation because of current velocity effect.
Reliability Analysis of Vertical Well Casing: Comparison of API 5C3 and ISO 10400
Authors: Halim Amirah Husna Abdul , Mustaffa Zahiraniza , Kim Do Kyun
Published: September 2018

Well casings are designed against burst strength pressure. The same formula is used in determining the remaining burst strength pressure of casing that suffered from wear. API 5C3 and ISO 10400 burst strength models are widely used to determine the burst strength pressure and the remaining strength of casing. This paper focus on the comparison of both burst strength models for its reliability assessment for vertical well casing. The limit state design method was used and adapted into this study to calculate the probability of failure for both burst strength models. The reliability analysis for both models is conducted using Monte Carlo simulation. The results show that ISO 10400 burst strength model can predict the probability of failure for vertical well casing when subjected to higher operating pressure compared to API 5C3 burst strength model. ISO 10400 burst strength model can predict probability of failure for higher operating pressure due to adaption of ultimate tensile strength as the strength parameter in the equation whereas API 5C3 has adopt yield strength as the strength parameter in the equation.
Near Fault Effect on the Response of Single Hinged Compliant Offshore Tower
Authors: Javed Syed Yusuf
Published: September 2018

The response of compliant offshore structure under simultaneous action of random waves and earthquake loading has been analyzed. Since earthquake forces play a significant role in affecting the response of these offshore structures, comparative studies have been carried out considering near fault and far fault seismic excitations in the presence of moderate random sea waves. The offshore tower is modeled as an inverted pendulum with a cylindrical shaft connected by an articulated joint at the base. Seismic forces are evaluated by dividing the tower shaft into finite elements with masses lumped at the nodes. The nonlinearities associated with the system owing to variable submergence, drag force, variable buoyancy along with the geometry are considered in the analysis. The nonlinear dynamic equation of motion is formulated considering Lagrangian approach, which is solved in time domain by the Newmark-beta integration scheme. The sea state conditions, more precisely the water particle kinematics are evaluated using Airy’s wave theory along with the stretching modifications, as suggested by Chakrabarti. To minimize the dynamic responses, emphasis has to be given to the variations in height and position of the buoyancy chamber in extreme wave condition. The results are expressed in the form of time histories of deck displacement, hinge rotation, hinge shear and the bending moment. Parameters like maximum, minimum, mean and standard deviation are also determined by statistical analysis of response time histories of the dynamic responses at articulated joint.
Comparison of Extreme Surface Elevation for Linear and Nonlinear Random Wave Theory for Offshore Structures
Authors: Mukhlas Nurul 'Azizah , Zaki Noor Irza Mohd , Husain Mohd Khairi Abu , Najafian Gholamhossein
Published: September 2018

For offshore structural design, the load due to wind-generated random waves is usually the most important source of loading. While these structures can be designed by exposing them to extreme regular waves (100-year design wave), it is much more satisfactory to use a probabilistic approach to account for the inherent randomness of the wave loading. This method allows the statistical properties of the loads and structural responses to be determined, which is essential for the risk-based assessment of these structures. It has been recognized that the simplest wave generation is by using linear random wave theory. However, there is some limitation on its application as some of the nonlinearities cannot be explained when higher order terms are excluded and lead to underestimating of 100-year wave height. In this paper, the contribution of nonlinearities based on the second order wave theory was considered and being tested at a variety of sea state condition from low, moderate to high. Hence, it was proven that the contribution of nonlinearities gives significant impact the prediction of 100-year wave's design as it provides a higher prediction compared to linear wave theory.
Effect of Water Depths on the Hydrodynamic Responses of an FPSO Platform
Authors: Guan Matthew , Ali Montasir Osman Ahmed , Ng Cheng Yee
Published: September 2018

Ship-shaped Floating Production Storage Offloading platforms (FPSO) are commonly used in the production of oil and gas in offshore deepwater regions. The vessel is held in place by mooring lines anchored to the seabed during operation, either in spread or turret mooring arrangement. When designing such systems, water depth is a main factor that needs to be considered. At greater depths, the hydrodynamic properties of mooring lines become important and may not be accurately predicted through traditional experiments or numerical quasi-static models. Numerical simulation using coupled dynamic analysis is thus recommended, as the hull-mooring behaviour is analysed simultaneously, and the damping and added mass properties of the entire mooring line system is taken into account. This paper investigates the motions and mooring line tensions of a turret-moored FPSO at various water depths ranging from 1000 m to 2000 m. The analysis focuses on numerical simulations in the fully coupled dynamic time domain. The study utilizes the commercial software AQWA, with the FPSO model subjected to a unidirectional random wave condition. The hull hydrodynamics is first solved using the 3D radiation/diffraction panel method, and the hull response equation is then coupled with the mooring line equation. The dynamic motions and mooring line tensions results are presented in terms of statistical parameters as well as response spectrum. The results highlight the significance of greater water depths on low frequency responses in surge motions and mooring line tensions, and provides insight on the increasing and decreasing trend of these responses.
Numerical Analysis of Crack Failure of Reinforced Thermoplastic Pipe (RTP)
Authors: Edmund Jonathan Emmanuel , Mustaffa Zahiraniza binti
Published: September 2018

Composite pipeline can drastically reduce losses caused by corrosion that occurs in carbon steel pipes in the industry. Multiple numerical testing has been conducted to determine maximum stress and strain a Reinforced Thermoplastic Pipe (RTP) can withstand before hitting failure. Not many studies were done to find the maximum stress intensity a defected RTP can resist before failing. Objectives are to validate the numerical model for Reinforced Thermoplastic Pipeline (RTP) to industry standard and to analyze the maximum stress intensity of Reinforced Thermoplastic Pipes (RTP) can withstand with various size of defects under constant pressure and incremental internal pressure with constant crack defect. Results were, under constant internal pressure of 6 MPa, the pipe will fail with a defect length of 2.05mm and at constant design pressure of 10 MPa, the pipe will fail with a defect length of 0.3mm. At constant crack depth and width, crack tip propagation (failure) is more dependent on internal pressure rather than crack length. However, when comparing the severity of crack depth to internal pressure, crack depth is the major cause of failure.
Holistic Design of HTHP Pipeline: PETRONAS’ Experience
Authors: Hayati Hayati , Jaafar Azam Syah , Latif Nur Atika Abdul , Aziz Mohd Faisal
Published: September 2018

When the oil and gas price was declining rapidly in 2016, it is prudent for global oil operator to identify opportunity to reduce the development cost. This is where all form of cost optimisation and holistic design approach have to be conducted, especially when dealing with High Pressure and High Temperature (HPHT) pipeline which normally requires higher CAPEX. Referring to a field case example from one of PETRONAS’s HPHT pipeline project in Malaysia waters, initial analysis had identified that a 24-inch subsea FWS HPHT pipeline with 40mm concrete coating thickness (for its on-bottom stability requirement), requires three numbers of ‘buckle trigger’s in order to manage the pipeline lateral buckling issues. Hence, a holistic design approach had been conducted to re-evaluate such requirement, commenced with detail assessment to look for all possible opportunities to reduce the pipeline temperature, one of it is to have a greater heat transfer from the pipeline. This exercise had landed into detail assessment on the pipeline on-bottom stability requirement which resulted in indication that the 24-inch FWS pipeline, that have a thicker wall thickness at the upstream portion, would be self-stabled - no requirement for concrete weight coating. Thus, benefitting from the results, further detail analysis had been conducted to assess the overall heat transfer from the pipeline as well as the impact towards the pipeline lateral buckling design, which lead to elimination of lateral buckling mitigation requirement. Unfortunately, further analysis had shown that in the absent of concrete weight coating, the pipeline un-concrete weight coated section i.e. hot end area and the field joints, would have rapid condensation and exposed to the intolerable top of line corrosion risk. Also, based on past experience with local installation contractor, there will be possibility of installation issue for the un-concrete coated pipeline with the tapered bracelet anode. Following that, thorough analysis had been performed and successfully mitigated the issue by applying field joint coating material with U-Value of 52 W/m2K to the 3LPP-Coated linepipe. As for the subsea flange connection, it is covered with thermal insulation, whereas the anode at the un-concrete coated section utilized anode sled mechanism. This holistic design approach had successfully reduced the project cost in line with PETRONAS’ aspiration i.e. low cost development project; and most importantly the ‘body of knowledge’ i.e. experiences, lessons learnt and good practices are captured in PETRONAS Technical Standard for future replication
Development of BIM-Based Safety Management Model Focusing on Safety Rule Violations
Authors: Othman Idris , Harahap Mohamad Irwan P. , Mohamad Hisham , Shafiq Nasir , Napiah Madzlan
Published: September 2018

Necessity of construction automation through BIM framework could no longer be set aside if we were to remain relevant and con-current in the ever-changing, technology-driven construction practices. The functions of construction safety management, i.e., hazard identification, assessment and control for construction works could certainly benefit from this technology through safety work automation which enhances the effectiveness and efficiency of the required safety processes. This paper aims to outline a research project for developing both information and technical requirements for BIM-based system via literature review, questionnaire survey, focus group, and prototype realization. The project results, to be validated by real projects, will act as solid platform for developing working model that can be employed at various project settings and safety circumstances. It will support the decision-making process with respect to safety enhancement and accident mitigation at the construction site.
Early Warning Signs of Project Failure
Authors: Othman Idris , Ghani Siti Norfarahhanim , Mohamad Hisham , Alalou Wesam , Shafiq Nasir
Published: September 2018

Despite the improvement in utilization of project management tools and techniques over the years, there are still many projects failed to meet their objectives. Early warning signs becomes one of the concepts used to detect the potential cause of failure in a project. Early warning is defined by signals, which can be seen variously as an expression, indication, a proof, or a sign of existence of some future negative issues. In recent years, several researches regarding early warning signs have been proposed by many authors, varying from project assessment stage in detecting the signs, methodology in conduction early warning sign research and the type of the projects tested. This article presents a review of related work on early warning signs of project failure to give conceptual insights on what early warning is.
Industry Revolution IR 4.0: Future Opportunities and Challenges in Construction Industry
Authors: Alaloul Wesam S , Liew Mohd Shahir , Zawawi Noor Amila Wan Abdullah , Mohammed Bashar S
Published: September 2018

The future of construction industry development is the approach of the component-industrialization, the construction-breakdown, design-identical, construction-assembled, operation-data technique to maximize the life cycle value. This paper presents a general idea of Industrial Revolution (IR) 4.0 with the introduction descriptions of important aspects in Construction Industry (CI) development. The aim is to define and show possible research areas connected with the IR 4.0 into the CI. For this purpose, an analysis was made, based on the most recent literature, to point out actual needs in the CI in terms of its evolution into IR 4.0 level. It is shown that multidiscipline approaches are not investigated to create special rules, procedures and methods and know-how designed for introducing the principles of IR 4.0 in the CI. A popular from stakeholders in the CI understand how digitization is affecting each part of their trade, however, its practical applications are still in infancy stage. IR 4.0 concepts should be combined with construction production, novel expertise must be applied to the intellectual engineering of modern construction, enhance the level of incorporation, to achieve the sustainable development.
Can Induced Magnetic Field Enhance Bioprocesses? - Review
Authors: Affam Augustine Chioma , Chung Wong Chee , Swee Wong Chee
Published: September 2018

This review presents a compilation of works with particular interest in the application of static magnetic field (SMF) to biological systems, wastewater treatment and few available reports on microbial granulation technology. It also highlights the effects of SMF on biological systems and wastewater treatment process. With an increasing need for environmentally conscious solutions to water purification and disinfection, wastewater treatment, bioremediation and other cheap alternative means, the application of SMF in biological water and wastewater treatment without increase in chemicals required may become an attractive option. Application of SMF has been reported to be successful in a number of fields including treatment of wastewater. However, there are sparse reports on SMF application in the formation and development of microbial granule and production of extracellular polymeric substances (EPS). Achieving a short start-up time in a bioreactor towards the development of microbial granule is of paramount importance in granulation technology. Ascertaining how effective varying strength of SMF and other input variables may enhance the microbial granule with respect to its physical, chemical and biological characteristics requires further research.
Preliminary View of a Smart Technique for Materials Testing in the Laboratory using FBG Sensor
Authors: Balarabe Isah W. , Hisham Mohamad , Niraku Ahmad R. , Harahap Indra S.H.
Published: September 2018

Simple experiments for calibrating Fibre Bragg Grating (FBG) in order to measure strain and temperature have been successfully demonstrated in this study. This will allow convenient use of FBG sensor in the laboratory for measuring quantities. Linear curve fittings were employed for both the strain and temperature, and R2 values are determined respectively. The result showed a perfect correlation between FBG, strain and temperature. The approach can be employed with ease, simplicity in an inexpensive manner, in order harness the advantages offered by FBG sensors such as accuracy, precision, speed and high resolution.
A Case Study on Offshore Platform Deformation Monitoring by using InSAR
Authors: Ab Latip Amir Sharifuddin , Matori Abd Nasir , Aobpaet Anuphao
Published: September 2018

The Interferometric Synthetic Aperture Radar (InSAR) technique is well established technique for onshore applications such as landslide, mining, volcano, urban and dam deformation monitoring. However, the ability of the InSAR technique for the offshore application particularly on the oil platform deformation monitoring is still a pending question. Therefore, a study needs to be conducted in order to assess the feasibility of the InSAR technique for monitoring the deformation of offshore platform. In this study, an advanced InSAR technique called Stanford Method of Persistent Scatterer (StaMPS) was utilized to process a stack of TerraSAR-X data. A mask has been developed as an additional module in the StaMPS to remove the noise on the ocean and relax the assigned condition imposed on the processing parameters. The results show that the number of persistent scatterer (PS) points on the offshore platform increased from 15 to 22 points and a smoother pattern of the velocity estimation could be seen when masking was applied to identify the deformation. Furthermore, some limitations and possible solutions of the PSI technique on the offshore platform application are summarized in this paper to guide future users on this application.
Effect of Pavement Surface Aging on Tire-Pavement Noise: A Case Study in the State of Qatar
Authors: Sirin Okan , Ohiduzzaman Md , Kassem Emad
Published: September 2018

The acoustical performance of asphalt pavements changes with time due to combined effects of environmental conditions and various distresses induced by repeated and heavy traffic. This study examined the changes in the acoustical performance of dense graded asphalt (DGA) pavements over time in the State of Qatar. Tire-pavement noise was measured using on board sound intensity (OBSI) method. The OBSI noise measurements were conducted on DGA pavements with different age and the results were analyzed to evaluate the effect of aging on tire-pavement noise. The results demonstrated that the tire-pavement noise increased with pavement age. The frequency analysis of three road segments showed that at early stage of pavement service life, the noise level is more affected at higher frequency due to the densification and increased air pumping mechanism. At later stage of pavement service life, the noise level is more affected at lower frequency due to the change in pavement surface conditions (e.g., cracking and raveling).
Car Ownership of Households in Sub-Urban Area in Makassar City
Authors: Pasra Mubassirang , Ramli Muhammad Isran , Dharmowijoyo Dimas Endrayana
Published: September 2018

The present study aims to grasp the car ownership characteristics of households in the sub-urban area in Makassar City, Indonesia. The study considers some exogenous characteristics of the households, such house types, family size, income, motorcycle ownership, trip number, and worker number. To construct the relationship between those characteristics and the car ownership, we applied the multinomial logit model approach. This study surveyed seven residential areas in the sub-urban area of the city. The survey conducted an interviewing method using a questionnaire sheet. The survey respondents as representative of the households, which selected randomly from the residential areas. The results show that the goodness of fit of the car ownership model is acceptable enough. Further, all of the exogenous variables significantly influence the households in car ownership. We expected that the results provide a basis for further studies such time valuation of car riders, mode choice model of the households, etc.
The Role of Airborne LiDAR Survey Technology in Digital Transformation
Authors: Ganendra Trudy R , Mobarakeh Ebrahim Taherzadeh
Published: September 2018

Civil engineering includes a wide range of applications that require three-dimensional (3D) information. With the advent of LiDAR (Light Detection And Ranging) technology, obtaining 3D terrain information accurately in a cost and time effective manner became more popular. In this paper, three case studies demonstrate the roles and applications of airborne LiDAR data including highway, transmission line and hydropower dam development projects. In first case study, the highway alignment was considerably changed after the initial design stage. LiDAR data was able to do the re-alignment survey quickly, allowing for prompt changes in design. In the next case study, a comparison is made between conventional transmission route alignment design and the design using PLS-CADD with LiDAR data. Utilizing the LiDAR data in PLSCADD allows transmission line engineers to model the construction costs of several alignments options effectively and efficiently compared to the conventional method. The last case study uses LiDAR for obtaining the necessary information for proposed dam. Using LiDAR data maximizes topological accuracy and volume measurements while minimizing survey time and costs. Furthermore, utilizing the multi-temporal LiDAR data can reveal valuable information such as topography changes. LiDAR survey technology has proven that it is the best method to capture accurate data from the earth surface which provides maximum density of topographical & digital imagery information for various applications.
Preliminary Investigation of Carbonation Problem Progress in Concrete buildings of North Cyprus
Authors: Malami Salim Idris , Akpinar Pinar , Lawan Mustapha Muhammad
Published: September 2018

Carbonation process is regarded as one of the most critical durability problem in concrete. As a result of carbonation process, the pH level in concrete is reduced and corrosion of reinforcements initiates, yielding significant damage both in reinforcements and concrete. This study, aimed to investigate experimentally on evaluation performance of existing reinforced-concrete structures prone to carbonation in North Cyprus. Five inland and five coastal concrete structures of ages varying between 10 and 41 years were selected as the focus of this study. The compressive strength was determined by testing concrete core samples extracted from the selected structures. Same core samples used for determination of carbonation depth, carbonation in the samples was measured by using phenolphthalein indicator test. A contribution to the related literature on carbonation resistance performance of concrete structures under varying exposure conditions of North Cyprus was made for the very first time with the results obtained from this study. Results shows that inland structures have more carbonation depths when compared with structures located in coastal areas. The result also shows that the final carbonation depths observed in the structures are highly depended on the age, initial quality of the concrete as well as the exact local exposure conditions.
Thermal and Mechanical Response of Partially Protected Steel I-Beam under Fire
Authors: Imran Muhammad , Liew Mohd Shahir , Nasif Mohammad Shakir , Gracia Enrique Munoz , Danyaro Kamaluddeen Usman , Niazi Muhammad Usama
Published: September 2018

Offshore and onshore structures continuously experience hydrocarbon fire accidents almost every year. To secured structure against extreme fire conditions, passive fire protection (PFP) is applied. However, PFP is a costly material which is applied only on critical structural members. Any unprotected surface can cause major structural damages during fire incidence if the behaviour of an unprotected surface is unknown. Usually, PFP applied easily around the column, but for beams, the application varies with the beam locations. In this paper the behaviours of steel beam compared with three different common scenarios such as fully protected, unprotected and partially protected under hydrocarbon fire. Fully protected beam has tremendous fire resisting capability compared to partially protected beams or unprotected beams. The study revealed that temperature of the top flange in partially protected beam exceeds more 600°C in less than 10 minutes which caused rapid failure in less than 30 minutes. Under extreme fire conditions the strength and stiffness of a beam affected which cause instability of structure during fire accident.
Structural Behavior of Steel-Concrete Composite Beam using Bolted Shear Connectors: A Review
Authors: Loqman Nadiah , Safiee Nor Azizi , Bakar Nabilah Abu , Nasir Noor Azline Mohd
Published: September 2018

Conventional steel-concrete composite beams have been recognized to exhibit stronger structural characteristics, in terms of strength and stiffness, when compared to pure steel or reinforced concrete beams. However, currently most steel beam is fully attached to the concrete slab; this means that the shear connectors are welded through the steel decking on to the steel beam and cast into concrete slab to fulfill the necessary shear connection. Recently, the deconstruction and reuse of the components almost impossible. In order to achieve a sustainable structural system, precast concrete slabs are attached to a steel beam using bolted shear connectors in prefabricated holes have been introduced as an alternative to the conventional connectors in steel – concrete composite beam system. This paper reviews the structural behavior of composite beam system such as the strength, stiffness, slip behavior, failure mode and sustainability obtained by experiment and numerical studies in order to address the applicability and efficiency of the composite beams having precast concrete slabs and bolted shear connectors.
Effect of NaOH Molarity on the Strength and Microstructure of Natural Pozzolan-Based AAC
Authors: Ibrahim Mohammed , Johari Megat Azmi , Rahman Mohammad Kalimur , Maslehuddin Mohammed , Dafalla Mohamed Hatim
Published: September 2018

Alarming levels of greenhouse gas emissions has triggered change in the mode of direction of building material research. In this pursuit, alkali activated binders (AAB), synthesized by activation of industrial by products and natural materials in the presence of highly alkaline solutions, have offered viable alternative to OPC. However, there are quite a number of variables which controls the properties of these binders. Among these parameters, SS/SH ratio and molarity of sodium hydroxide solution plays a very important role in the development of these binders. Therefore, this research investigates the effect of SS/SH ratio, subsequently, molarity of SH solution on the properties of natural pozzolan based AAB. The NP was activated with sodium silicate to sodium hydroxide ratio (SS/SH) between 2.0 to 2.75. Subsequently, the molarity of SH solution was varied between 8 to 14. The development in strength was monitored on the specimens cured at 60 °C. SEM and EDS techniques were used to determine the nature of the binder formed during alkali activation. The results have shown that SS/SH ratio of 2.5 and 14 molar SH solution resulted in higher strength and finer microstructure as compared to others. Also, it was understood that there exists a suitable silica modulus of combined activator which results in higher polymerization.
Properties of Self-curing High Strength Concrete by using Baby Polymer Diapers
Authors: Beddu Salmia , Mohamad Daud , Nazri Fadzli Mohamed , Sadon Siti Nabihah , Elshawesh Mohamed Galal
Published: September 2018

This study investigates the self-curing concrete using baby polymer diapers as substitute method of curing process in order to improve mechanical and physical properties of concrete. Three different proportion of baby polymer diapers which are 1%, 3% and 5% were mix with concrete. Slump, compressive strength and drying shrinkage test were performed in order to study the workability, strength and durability of the concrete. All concrete were tested for 1, 3, 7, 14, and 28 days for drying shrinkage test. Meanwhile, all concrete were test at 3, 7 and 28 days for compressive strength test. Compressive strength of concrete containing 5% baby polymer diapers show the highest strength at 28 days compared to others percentage. Thus, it indicates that application of baby polymer diaper as self-cure agent can improve the concrete performances.
Bending Behaviour of Post-tensioned Interlocking Block Masonry Wall
Authors: Muda Zakaria Che , Naganthan Sivakumar , Balasingam Vicki Balaiah , Beddu Salmia , Sadon Siti Nabihah
Published: September 2018

Interlocking soil blocks are on of modern techniques of house construction due to its durability. The use of these blocks fits suitably within the production cost and environmental quality as an alternative to fired bricks. This paper reports the result investigation done on walls made using interlocking soil blocks. Three types of walls with different combination of reinforcements were tested. The performance is assessed in terms of cracking patterns, failure modes and load-deflection characteristic. Results show that the ductility of all walls are good and wall with post-tensioned bars performed the best. The post tensioned walls are able to deflect up to 42% without any failure compare to non pre stressed wall. The walls with combination of reinforcement and post –tensioned systems are more ductile compare to walls with reinforcement only. It is concluded, post-tensioned wall developed using interlocking soil blocks can be used in reinforced and post-tensioned masonry application instead of conventional brick masonry.
Investigation of Water Losses in Water Supply System: Muscat as a Case Study
Authors: Al-Bulushi Manal M. , Al Sulti Maha M. , Abushammala Mohammed F.M.
Published: September 2018

One of the problems affecting water supply systems in Oman is the problem of water loss and Non-Revenue Water (NRW). The aim of this research is to carry out water auditing for Al Seeb water distribution network as a case study to estimate the water losses, NRW, water balance, and the resulting financial and operational impacts. Annual data on water supplies, water consumption, system data, and cost data for the years from 2010 to 2014 was collected from the Public Authority for Electricity and Water (PAEW) and the analysis was done using the American Water Works Association (AWWA) audit software to determine water losses including real and apparent losses, NRW, water balance, and the cost. The results indicated that the average of apparent loss, real loss, and NRW from 2010 to 2014 was approximately 19.5%, 21%, and 40 % respectively. It was estimated that the average annual cost of NRW between the years 2010 and 2014 was approximately 9.4 million USD, which was approximately 33% of the total revenue budget. In conclusion, there is a need for the development of water management systems to provide the best management practice system to further minimize NRW problems in Oman.
Advances and Challenging Issues in Subsurface Drainage Module Technology and BIOECODS: A Review
Authors: Abdurrasheed Abdurrasheed Sa'id , Yusof Khamaruzaman Wan , Takaijudin Husna Bt , Ghani Aminuddin Ab. , Muhammad Muhammad Mujahid , Sholagberu Abdulkadir Taofeeq
Published: September 2018

Subsurface drainage modules are important components of the Bio-ecological Drainage System (BIOECODS) which is a system designed to manage stormwater quantity and quality using constructed grass swales, subsurface modules, dry and wet ponds. BIOECODS is gradually gaining attention as one of the most ecologically sustainable solutions to the frequent flash floods in Malaysia and the rest of the world with a focus on the impact of the subsurface modules to the effectiveness of the system. Nearly two decades of post-construction research in the BIOECODS technology, there is need to review findings and areas of improvement in the system. Thus, this study highlighted the key advances and challenges in these subsurface drainage modules through an extensive review of related literature. From the study, more work is required on the hydraulic characteristics, flow attenuation and direct validation methods between field, laboratory, and numerical data. Also, there is concern over the loss of efficiency during the design life especially the infiltration capacity of the module, the state of the geotextile and hydronet over time. It is recommended for the sake of higher performance, that there should be an onsite methodology to assess the permeability, rate of clogging and condition of the geotextile as well as the hydronet over time.