bluuebunny/crossref_metadata_2025 huggingface dataset:
Complimentary Sensitivity Function based Novel Cascade Control Structure for Automatic Generation Control
Authors: Kameswari B S Durga , Padhan Dola Gobinda
Published: February 2019

This paper introduces a series cascade control structure for automatic generation control. The control structure consists of two loops such as Primary loop and auxiliary loop (secondary loop). The secondary loop controller is designed using internal model control (IMC) approach. The primary loop controller is a PID controller which is tuned using desired complimentary sensitivity function. The beauty of the control structure is that it effectively nullifies the disturbances entering to the secondary loop as well as primary loop. The efficacy of the proposed controller is shown by comparing the simulation results with the existing methods in the literature.
IoT Based Displacement Detection Using Wireless Sensor System
Authors: Bajarangbali  , Jadhav Vinay Kumar , Druvitha Nagarur , S Pavan Kumar
Published: February 2019

The main objective of this work is to monitor the base position of evenly or unevenly distributed containers by analyzing and establishing a reference point for the object. The displacement of the container is measured with the help of ultrasonic sensors each connected to nodemcu. Using nodemcu, sensor values are sent wirelessly to microcontroller that is specifically designed for IoT applications. Microcontroller will then compare the received sensor values with reference values. If there is any displacement of the container, warning is given to truck driver by buzzer and SMS, E-mail is sent to intended recipient.
Un territoire de la dissuasion nucléaire: le plateau d’Albion
Authors: Monier Frédéric
Published: February 2019

A territory for nuclear deterrence: high plains of Albion. This presentation studies the social silence surrounding recent French history, in the cold war period. The case study concerns social and political perceptions of the former strategic missile base located in Albion, active from 1970 to 1996, and then dismantled. The decision to create the missile base in this French heartland was taken by the Gaullist power in Paris in 1965, without considering local expectations. This arouse strong national and local conflicts, both political and cultural, in the 1960’s, between supporters of the militarization and its opponents. Nuclear missiles were not welcome by all: anxiety and new popular culturesuch as rumours about UFO’stestify for the entering in a new age. Was there a real patriotic consent to cold war? Resignation and fatalistic attitudes seem to have prevailed. Since the late 2000’s, i.e. twenty years after the demilitarization of Albion, some former servicemen still denounce the activities linked to nuclear missiles as responsible for radioactive contamination and persistent diseases. This history, not investigated nor written yet, should highlight the reluctant and ambivalent attitudes of the French society when entering nuclear age.
Contribution to the modeling and the mechanical characterization of the subsoil in the LSBB environment
Authors: Bouare Hamed , Mesgouez Arnaud , Lefeuve-Mesgouez Gaëlle
Published: February 2019

The present research work aims at better characterizing the specific underground environment of the LSBB (Low Noise Inter-Disciplinary Underground Science and Technology, Rustrel, France) using mechanical wave propagation information. The LSBB experimental environment is characterized by a system of cylindrical galleries, some of them presenting a concrete layer. In the global project, three steps are considered : firstly the construction of an efficient forward mechanical wave propagation model to calculate the displacement vector and stress tensor components; secondly a sensitivity analysis to extract the pertinent parameters in the configurations and models under study (viscoelastic or poroviscoelastic media with potential anisotropy); and lastly an inversion strategy to recover some of the pertinent parameters. In this proposal, the first step, under progress, is described. The work carried out is in the continuity of the work presented by Yi et al. (2016) [1] who studied the harmonic response of a cylindrical elastic tunnel, impacted by a plane compressional wave, embedded in an infinite elastic ground. The interface between the rock mass and the linen is an imperfect contact modeled with two spring parameters, Achenbach and Zhu (1989) [2]. We choose a semi-analytical approach to calculate the two-dimensional displacement and stress fields in order to get a fast tool, from the numerical point of view. The main steps of the theoretical approach are : use of the Helmholtz decomposition, solving the wave equation based on the separation method and the expansion in Bessel function series in the harmonic domain. The harmonic results are validated by comparison with Yi et al. (2016) [1] and new ones are presented. Moreover, the transient regime case obtained with the use of a Fourier transform on the time variable, is under progress.
Different Ratios of Electron Beam Welding of Dissimilar Titanium Alloys: Ti-10V-2Fe-3Al and Ti-6Al-4V
Authors: Iman Utama Muhammad , Ageng Nugroho Janu , Aziz Ammar Abdul , Park Nokeun , Ryul Baek Eung
Published: February 2019

A welding of dissimilar alloy gives an optimum combination of high strength of Ti-10V-2Fe3Al (Ti1023) and low cost of Ti-6Al-4V (Ti64). Three different fusion ratios of Ti1023 and Ti64 were resulting in a similar width size of the fusion zone (FZ) and heat affected zones (HAZ) whereas a thicker sample with the same fusion ratio generated a narrower size of FZ and HAZ. It resulted chemical composition in the FZ within a low β phase stability than in Ti1023, which allowed the precipitation of high hardness α” martensitic in the as weld condition. In the HAZ of Ti1023, αs transformed into β phase, which reduced the hardness and strength. Vickers hardness measurements confirmed the HAZ of Ti1023 was the softest area whereas the FZ was the hardest area. Consequently, in the as weld condition, the fracture occurred in the HAZ of TI1023 after the tensile test.
A Feasibility Study Comparing Two Commercial TIG Welding Machines for Deep Penetration
Authors: French Richard , Merin-Reyes Hector , Yeadon Will
Published: February 2019

Developing a deep penetration TIG welding technique to produce welds of equal quality to the industrial standard practise of laser-based welding techniques has the potential to lower production complexity and cost. Higher currents levels are required to increase penetration depth in conventional TIG welding but this results in excessive weld bead width amongst other detrimental effects. However, through K-TIG and A-TIG techniques these detrimental effects can be circumnavigated. Prior experimental work on weld pool dynamics in conventional TIG welding in higher current regions has been sparse as TIG welding enhanced through novel techniques provides the best quality welds. This paper is an early feasibility study for novel deep penetration welding techniques motivated by observations made during research done at The University of Sheffield where unexpected activity in the weld pool was identified during TIG welding with a VBC IE500DHC between 300A – 1000A. This current range is labelled the ‘Red Region’. Understanding the fluid dynamics of the molten metal in the weld pool at the ‘ Red Region' current level will help in the creation of novel techniques for deep penetration TIG welding. Addressing this, this paper compares the quality of welds produced between 100A and 200A on 316 Stainless Steel by two industrially leading welding machines; the Miller Dynasty 350 and the VBCie 500DHC.
Mechanical Properties and Microstructure of Friction Stir Spot Welded 6082-T6 Aluminium Alloy Joint
Authors: Muhayat Nurul , Priatmana Putra Bobby , Triyono
Published: February 2019

Friction stir spot welding (FSSW) can substitute resistance spot welding (RSW) to avoid the problem due to melting materials during welding. In this investigation, a friction stir spot welded 6082 T6 joint was made to study the effect of pin diameter and dwell time on mechanical properties and microstructure with variation of pin diameter and dwell time. In the stir zone, it is observed that the grain structure is fine equiaxed recrystallized grain whereas in the HAZ, it is coarse grain. The increase of pin diameter and dwell time lead to the increase of tensile shear load. The highest tensile-shear load obtained is 4987.1 N at the highest pin diameter of 7 mm and dwell time of 3 seconds, while the lowest one is 788.2 N that obtained at pin diameter pin of 3 mm and dwell time 3 second. The highest micro Vickers hardness obtained at stir zone of 96.2 VHN, while the lowest one is 42.1 VHN.
Some Hints to Develop Particular Line Pipe Specification
Authors: Fandika Ardian
Published: February 2019

When procuring the carbon steel line pipe for pipeline project, frequently the purchaser refers to the international standards/specifications such as API SPEC 5L without any particular requirements. Many users thought these standards/specifications already addressed what are needed in their project; but unfortunately it is not completely true. The specification such as API SPEC 5L clearly mentioned in the special notes section that the users should not rely exclusively on the information contained in the specification and it is users’ responsibilities to define the product characteristics which meet the design criteria and suitable for the construction and the operation of the installation (e.g. pipeline). Through this paper, the author tries to give some ideas on particular specification for line pipe.
Analisys of Welding Crack on The Under Frame of Wagon for Cement Bags Transportation Using Euro Code, Measurement and Finite Element
Authors: Sasmito Agus , Irawadi Yudi , Soebagyo Hary
Published: February 2019

The Underframe of Wagon steel structure have both complex geometry and loading conditions producing complex Underframe structure behaviour which is hard to estimate and analyse using the traditional fatigue calculation methods. The impacts of the loading direction, loading type and detail geometrical shapes, i.e. Underframe components which are working in a group, need to be considered carefully in the stress analysis. Using the assumption of elastic behavior for all the underframe structural systems, in which sources of stress increased that have significant effects on the fatigue strength capacity are several included, can over/lower yield stress values to be analyzed in fatigue design. The application of the advanced stress assessment methods in the welding area using the Euro Code calculation studied in this paper produces more accurate stress results that can explain welding crack during operation in The car body of Wagon Steel. Based on Euro Code stress assesment, FEM analysis and measurement can be known that crack on the welding joint of wagon bottom part due to lack finishing of the welding joint. The IIW recommendations can be use in order to repair welding joint finishing to avoid crack fatigue.
Effect of Long-term Service on Microstructure and Mechanical Properties of NiCrMoV Steel Welded Joint
Authors: Fan Manjie , Wang Peng , Sun Qixing
Published: February 2019

The influences of prolonged service on microstructure evolution and mechanical properties of NiCrMoV steel welded joint in an ex-service welded steam turbine rotor were investigated. The welded rotor had been operated for 22 years since 1991. The specimens for the present study were taken from the location where the temperature was as high as 230°C. The optical microscope (OM) showed that even after long-term service, there were no obvious defects such as creep cavities, cracks found in the microstructure of the whole welded joint after such a long term service. The microstructure was uniform and no obvious grain coarsening was observed. However some black strip-shaped zones were found in base metal and heat affected zone (HAZ). The distribution of hardness across the welded joints showed no anomalies. The results of tensile strength and fracture toughness tests demonstrated that the welded joint still exhibited excellent. Mechanical performance after long-term service, indicating that the welding process of Shanghai Turbine Plant was reliable and stable. With the improvement of forging and welding qualities and improved heat treatment furnaces with more accurately controlled temperature, it is reasonable to assume that the current large low-pressure (LP) welded rotors are definitely safe to operate under similar service conditions for designed life.
Influence of Interpass Temperature on Wire Arc Additive Manufacturing (WAAM) of Aluminium Alloy Components
Authors: Derekar Karan , Lawrence Jonathan , Melton Geoff , Addison Adrian , Zhang Xiang , Xu Lei
Published: February 2019

Wire arc additive manufacturing (WAAM) technique has revealed the potential of replacing existing aerospace industry parts manufactured by traditional manufacturing routes. The reduced mechanical properties compared to wrought products, the porosity formation, and solidification cracking are the prime constraints that are restricting wide-spread applications of WAAM products using aluminium alloys. An interpass temperature is less studied in robotic WAAM and is the vital aspect affecting the properties of a formed product. This paper highlights the effects of change in interpass temperature on porosity content and mechanical properties of WAAM parts prepared using DC pulsed GMAW process, with 5356 aluminium consumable wire. The samples prepared with different interpass temperatures were studied for the distribution of pores with the help of computed tomography radiography (CT radiography) technique. A WAAM sample produced with higher interpass temperature revealed 10.41% less porosity than the sample prepared with lower interpass temperature. The pores with size less than 0.15mm3 were contributing over 95% of the overall porosity content. Additionally, on a volumetric scale, small pores (<0.15mm3) in the higher interpass temperature sample contributed 81.47% of overall volume of pores whereas only 67.92% volume was occupied in lower interpass temperature sample with same sized pores. The different solidification rates believed to have influence on the hydrogen evolution mechanism. Tensile properties of higher interpass temperature sample were comparatively better than lower interpass temperature sample. For the deposition pattern used in this study, horizontal specimens were superior to vertical specimens in tensile properties.
WAAM Application for EPC Company
Authors: Agustinus Ananda Priyantomo
Published: February 2019

WAAM ( Wire + Arc Additive Manufacturing) is a process of adding material layer by layer in order to build a near net shape components. It shows a further promising future for fabricating large expensive metal components with complex geometry. Engineering Procurement and Construction (EPC) company as one of the industrial section which related with engineering design and products, wide range of material type, and shop based or site based manufacturing process have been dealing with conventional manufacturing and procurement process in order to fulfill its requirement for custom parts and items for the project completion purpose. During the conventional process, there is a risk during the transportation of the products from the manufacturing shop to then site project, this risk is even greater when the delivery time take part as one of the essential part which affect the project schedule. Wire Arc Additive Manufacturing process offering an alternative process to shorten the delivery time and process for a selected material and engineered items, with the consideration of essential variables which can affect the final products of WAAM process, such as : heat input, wire feed speed, travel speed, shielding gas, welding process and robotic system applied. In this paper, the possibilities of WAAM application in EPC company will be assessed, an in depth literature review of the various process which possible to applied, include the loss and benefit compared with conventional method will be presented. The main objective is to identify the current challenge and the prospect of WAAM application in EPC company.
Development of Bead Modelling for Distortion Analysis Induced by Wire Arc Additive Manufacturing using FEM and Experiment
Authors: Prajadhiama Keval P , Manurung Yupiter HP , Minggu Zaidi , Pengadau Fetisia HS , Graf Marcel , Haelsig Andre , Adams Tom-Eric , Choo Hui Leng
Published: February 2019

In this research, Wire Arc Additive Manufacturing is modelled and simulated to determine the most suitable bead modelling strategy. This analysis is aimed to predict distortion by means of thermomechanical Finite Element Method (FEM). The product model with wire as feedstock on plate as substrate and process simulation are designed in form of multi-layered beads and single string using MSC Marc/Mentat. This research begins with finding suitable WAAM parameters which takes into account the bead quality. This is done by using robotic welding system with 01.2mm filler wire (AWS A5.28 : ER80SNi1), shielding gas (80% Ar/ 20% CO2) and 6mm-thick low carbon steel as base plate. Further, modelling as well as simulation are to be conducted with regards to bead spreading of each layers. Two different geometrical modelling regarding the weld bead are modelled which are arc and rectangular shape. Equivalent material properties from database and previous researches are implemented into simulation to ensure a realistic resemblance. It is shown that bead modelling with rectangular shape exhibits faster computational time with less error percentage on distortion result compared to arc shape. Moreover, by using the rectangular shape, the element and meshing are much easier to be designed rather than arc shape bead.
Fatigue Life Enhancement of Transverse and Longitudinal T-Joint on Offshore Steel Structure HSLAS460G2+M using Semi-automated GMAW and HFMI/PIT
Authors: Andud Dahia , Mat Muhd Faiz , Manurung Yupiter HP , Saidin Salina , Nordin Noridzwan , Muhammad Norasiah , Laitner Martin
Published: February 2019

This research deals with a method and procedure for enhancing the structural life of the commonly used steel structure in oil and gas industries HSLA S460G2+M with a thickness of 10 mm. The type of joint and welding process is T-joint with transverse and longitudinal attachment welded using semi-automated GMAW. Filler wire ER80S-Ni1 and mixed shielding gas (80% Ar / 20% CO2) is used as material consumables. At first, the best suitable welding parameters are comprehensively investigated, prepared, tested and qualified according to welding procedure specification (WPS) qualification requirements. Further, the weld toe is treated by using HFMI/PIT with a frequency of 90Hz, 2 mm pin radius and air pressure of 6 bars. In accordance with the recommendation of the International Welding Institute (IIW), fatigue test is conducted using constant amplitude loading with the stress ratio of 0.1 and loading stresses from 55% to 75% of the yield strength of the material. Finally, the results of the fatigue experimental are compared with the fatigue recommendation of as-welded and HFMI/PIT of IIW as well as the untreated raw material. As a conclusion, it is observed that the fatigue life is increased up to 300% compared to IIW and 70% to as-welded. It is also obvious that treated transverse T-joint shows significant improvement than the longitudinal attachment.
Microstructure Evolution and Distribution of Mechanical Properties in Shielded Metal Arc Welded Dissimilar DSS 2205 and HY80 Joints
Authors: Mudiantoro Sunoto , Winarto Winarto , Oktadinata Herry
Published: February 2019

Dissimilar welding is a unique and complex process because in each zone in the different welding area have unique structures and characteristics. The modified structure may have a significant effect on weld metal properties. In this research, the primary objective is to investigate the microstructure evolution and hardness distribution mode of a different joint HY80 steel plate and Duplex type 2205 welded by using thick weld or shielded metal arc weld (SMAW). The microstructure of weld metal zones was observed. The test plates were welded in both butt joint and fillet joint by using E309L filler metal. It was found that the 309L electrode provides the equilibrium between austenite and ferrite phase in the different weld metal zones of DSS 2205 and HY80 steel joint. The results show that hardness distribution of different joint of both butt weld and fillet weld presents sinusoidal trend, where hardness in HAZ is highest. The peak value of hardness appeared in HY 80 base metal near the fusion line. The microstructure of base metal DSS 2205 shows fine grains of ferrite and austenite grains with dark and light shades respectively. The microstructure of weld metal shows coarse grains of austenite along with some slag inclusions as dark spots. The Heat Affected Zone of HY80 steel plate shows coarse grains of austenite and ferrite, while the heat affected zone of DSS 2205 shows thin fusion line with coarse grains of ferrite as dark zones and coarse grains of austenite as light zones. There is, a degree of variation in weld metal ferrite content was observed. Keywords: Duplex Stainless Steel, HY80, SMAW, Dissimilar Joint, Hardness, and Impact Toughness.
The Effect of Melting Temperature Aluminum Metal Casting Using Mixed Degasser Based Sodium Fluoride and Sodium Nitrate
Authors: Dhaneswara Donanta , Fajar Fatriansyah Jaka , Ramadhan Raffi , Ashari Ahmad
Published: February 2019

The effect of NaF and NaNO3 based degasser on mechanical properties of Al-Si 12% casting has been investigated. The quality of Al-Si casting, especially in mechanical properties, is important in some applications. However, the existence of gas porosity, which is formed due to the high solubility of H2 at melt temperature in casting process, reduces mechanical propertis of Al-Si 12% casting product. In this research, we used NaF and NaNO3 as degasser as an addition in casting process. The experiments were conducted at pouring temperature of 660°C, 680°C, 700°C and 720°C. The mechanical properties (which are determined by tensile test, hardness test and impact test) with and without degasser were measured and compared. We found that in all pouring temperature, the addition of degasser will improve all of mecahnical properties measured. In addition we found that the increase of tensile strength was optimum at pouring temperature of 720°C at 25,5 % of increase, hardness was optimum at pouring temperature of 720°C at 33,3 % of increase and impact strength was optimum at pouring temperature of 720°C at 25 % of increase. The improvement of mechanical properties is due to the role of NaF and NaNO3 by binding H2 gases which is formed in melting process. This H2 binding was shown in microstructure observation which shows that the porosity of casting product visually decreased.
Initial Study for Cerium and Lanthanum Extraction from Bangka Tin Slag through NaOH and HClO4 Leaching
Authors: Munir Badrul , Permana Sulaksana , Amilia Anggita , Maksum Ahmad , Soedarsono Johny W
Published: February 2019

The global demand for rare earth elements have increased dramatically for the last decade as more and more devices use rare earth elements as key for their advanced properties. The paper explores the possibilty to recover cerium (Ce) and lanthanum (La) in Bangka tin slag (BTS) involving roasting at 900°C, water-quenching, and two leachings, 8M NaOH leaching and HClO4 leaching at concentrations of 0.1M, 0.4M, and 0.8M. HClO4 leaching causes Ce and La contents to decrease to 0.47% for 0.1M, 0.51% for 0.4M, and 0.59% for 0.8M. On the other hand, 8M NaOH optimizes cerium and lanthanum contents up to 4.35% and 1.45%, respectively.
Foundation resistance analysis of Cisomang Bridge
Authors: Tamara Kaisha , Ilyas Tommy
Published: February 2019

Cisomang bridge is one of the bridges connecting Jakarta and Bandung through Cikampek-Padalarang (Cipularang) Highway. The Road and Bridge's Research and Development Centre (PUSJATAN) presents data that on December 23rd, 2016 Pier P2 of Cipularang Highway is shifted for 57,02 cm. This movement is suspected occurred due to decreasing of clayshale's shear strength caused by Cisomang River's seepage. Pier P2 movement is indicating lateral displacement of Cisomang Bridges foundation for 22 m deep which dominates the total displacement when compared to its settlement. Accordingly, we study trough back analysis method for determining the impact of bore pile reinforcement to lateral displacement on clayshale using PLAXIS to simulate the behaviour of soil. This research proposes 35 m and 60 m depth bore pile to be a foundation reinforcement. Aside from its contribution on decreasing lateral displacement of existing foundation up to 33-68%, this reinforcement cuts the slip surface of Cipularang slope and increases its safety factor (SF) for 4,7-16%.
Analysis of embankment slope stability: the comparison of finite element limit analysis with limit equilibrium methods
Authors: Yingchaloenkitkhajorn Kongkit
Published: February 2019

This paper presented the analysis of embankment slope stability by considering the problem of embankment slope stability with special effects that it was filled with sand and was placed on purely cohesive clay. The finite element limit analysis of two-dimensional plane strain was employed to analyze the stability of this problem. The embankment slope height (H), the depth factors (d/H) and the embankment slope angle (β) for the finite element limit analysis of sand was modeled as a volume element with the properties of Mohr-Coulomb material in drained condition. And the clay was modeled as a volume element with the properties of Tresca material in undrained condition where the parameters were soil unit weight (γ), undrained shear strength (su) and friction angle (φ′). Parametric studies consisted of three dimensionless variables including depth factors (d/H), friction angle (φ′) and embankment slope angle (β). Results were summarized in the form of the dimensionless stability number (su/γH(FS)) and the design chart and application were presented. In addition, the comparison of the solution of stability number with the limit equilibrium methods and the failure mechanisms were also proposed in this paper.
Water management system of peatlands for palawija plants on KHG Pulang Pisau, Central of Kalimantan
Authors: Khalifah Ibrahim Fadel , Suryadi Yadi , Soekarno Indratmo , Legowo Sri , Bagus Adityawan Mohammad , Saepul
Published: February 2019

Kesatuan Hidrologis Gambut (KHG) or Peat Hydrological Unit is a land which consist of incomplete soil decomposition of aquatic vegetation that is inundated with anaerobic conditions. Peatlands in Indonesia have common problem, which is adequacy of water availability (water balance) throughout the year and fire risk. This condition makes the holding of studies to ensure this. In this research, study uses secondary data of Peatlands, Pulang Pisau regency, Central of Kalimantan. This research will be modeling groundwater level using unconfined steady aquifer with finite difference method by Qgis Freewat. Then, if possible, the model will be calibrated by direct sampling at some point in the field, so the next will be modeling by comparison results of water level model with water level existing that up to 40 cm in accordance with Government Regulation no. 57 of 2016 on amendment to Government Regulation No. 71 of 2014 on the Protection and Management of Peat Ecosystems. From this research is expected to give some of benefits as follow: 1). Estimating water balance for Palawija Plants in KHG Pulang Pisau, 2). Modeling groundwater level for canal as one of the optimal water management efforts so that peatlands are not too dry and not too wet, so the risk of forest fires can be minimized.
Rainwater management role to solve problem related to hydro- environment engineering
Authors: Cicilia Laurentia Susilawati , Suni Yulius PK , Fredrich Lukas Alfred
Published: February 2019

The problems related to hydro-environmental engineering on small islands are flood and drought, for the less favourable rainfall characteristics. Big rainfall intensity comes and flows immediately as storm runoff to the sea because of short distance, and no chance to infiltrate into the soil as ground-water recharge. Floods and landslides occur during rainy season and drought during the dry season. This research investigates the role of rainwater management in order to overcome these problems. The literature review and field observations of experiences on rainwater management techniques applied on both communal scale and household level. The results show that firstly, rainwater must be managed in ways that small amount of rainwater flows out immediately to the sea. So, it has the chance to infiltrate into the soil as ground-water recharge. This is done by making some water-traps series, harvesting rainwater and storing it into the ponds at the household scale. The water then could be utilized for domestic and agriculture purposes. Secondly, learning from several experiences’ technology implementation as water conservation, it can be found the right way to manage rainwater at communal/household scale. These actions give the rainwater management having contributions to solve problems related to hydro-environments engineering.
Study of the relation between hydraulic jump and the flood water level in the river on the downstream of a spillway
Authors: Anbiya Taruna Dwiva , Bagus Adityawan Mohammad , Nugroho Joko , Farid Mohammad , Kuntoro Arno Adi , Widyaningtias
Published: February 2019

Kuningan Dam which is located in Kuningan District, West Java has 21,8 km2 watershed area. This dam also acts as a flood control facility which functions supported by the reservoir’s topography and its spillway building. The spillway building releases excess water from the dam into the downstream area. In the downstream part of the spillway, usually, hydraulic jump phenomenon occurs which depends on the flood water level of the river. The hydraulic jump used in the designing process of stilling basin length. The stilling basin in the spillway building generally designed using Q100. The spillway in Kuningan Dam is designed as a closed conduit channel. In this study, the Kuningan Dam spillway is re-designed as an open channel using ogee type spillway. Based on the modeling result, the length of hydraulic jump that occurs when modeled with the return period discharge of Q25 is 21.54 m, Q50 is 16.65 m, and Q100 is 0.98 m. It is seen that in Q25 the jump was the furthest, so an elaborate study regarding hydraulic jump phenomenon and design standards of the spillway is required.
The effect of small dams in Rawa Pening catchment area on sedimentation rate of Rawa Pening Lake
Authors: Ari Wulandari Dyah , Kurniani Dwi , Edhisono Sutarto , Ardianto Ferdian , Dahlan Denri
Published: February 2019

Rawa Pening Lake is one of fifteen priority lakes. The problem in Rawa Pening Lake is the rapid sedimentation rate and blooming of water hyacinth which has an impact on the decreasing of storage capacity and water quality. The handling has not shown significant results. Therefore, that it needs to innovate on improvement and maintenance of Rawa Pening Catchment Area that has never done that is in the form of small dam development in Rawa Pening catchment area. The construction of a small dam in the Rawa Pening catchment area can temporarily hold water and prevent the rate of sediment from entering the lake. The purpose of this research is to analyse the influence of small dams in the Rawa Pening catchment area to sedimentation rate in Rawa Pening Lake. Sedimentation is calculated based on soil erosion in the catchment area, using the USLE formula. If There are 40 small-dams in Lake Rawa Pening catchment area, the sedimentation decreased to 78.75%. If there are only 2 small-dams constructed in the Klegung sub-watershed and the Legi sub-watershed, the sedimentation decrease to 67%.
FVCOM model simulation of local scouring around bridge pile
Authors: Herdiansyah Sony , Kardana Natakusumah Dantje , Harlan Dhemi
Published: February 2019

Scouring is one of many damages that water can cause. Scouring can occur as a consequence of bridge pile existence. The problem on local scour around single pier will be studied by using FVCOM numerical model. This study objective is to find out how accurate FVCOM model to predict local scour behavior. FVCOM model is based on the finite volume method to solve Navier Stokes, Meyer Peter Muller, and Exner equations. FVCOM computed numerical result then will be verified with computed and measured data in previous numerical (FSUM model) and experimental study. Results from this study show FVCOM model were successfully simulated typical features of local scour around piers such as downflow and wake vortex, but failed to simulate horseshoe vortex. Both computed numerical (FSUM and FVCOM) results are then compared with measured experimental data for its magnitude and time-series of maximum scour depth. FVCOM result shows value 0.99 r-squared correlation and 5.96 percent average error, and FSUM result shows value 0.98 r-squared correlation and 6.82 percent average error. Therefore, it can be deduced that FVCOM successfully predict local scour depth and its time-series and proven that FVCOM is more accurate than FSUM model.
Computing urban flooding of meandering river using 2D numerical model (case study : Kebon Jati-Kalibata segment, Ciliwung river basin)
Authors: Indrawati Dian , Yakti Bagus , Purwanti Agustin , Hadinagoro Rono
Published: February 2019

This research is an extension from a previous study titled modelling the diversion channel at Kalibata-Kebonjati meandering segment in Ciliwung watershed. Based on http://pusatkrisis.kemkes.go.id data, there are five sub districts that were flooded because of the rainfall in 5 February 2018 i.e : Pasar Minggu, Pancoran, Cilandak, Jagakarsa and Tebet. Their flood levels were achieved 300 cm, and the worst disaster happened in Pancoran, at Kebonjati to Kalibata segment in particular. Thus, this segment needs to manage accurately with appropriate structures. Formerly, the last study using 1D HEC-RAS, but the model has several lackness related to the rates of meandering velocities and discharges at the river edges, whereas, these numbers have significant effects for river scouring. Since several studies which applied 2D and 1D/2D coupling hydraulics modelling have been providing satisfactory results on complex river, this research was redeveloped and compared the meandering segment by using 2D HEC-RAS and Coupling 1D/2D HEC-RAS. Using rainfall data from three stations (Bendung Gadog, FT UI and Gunung Mas), the models indicated better results comparing with 1D model beside relations between velocity and discharge, respectively. Further, a diversion channel and stilling basin will be held in order to manage the flooding and scouring issues.
1D Numerical modelling of dam break using finite element method
Authors: Lely Hardianti Zendrato Nur , Harlan Dhemi , Bagus Adityawan Mohammad , Kardana Natakusumah Dantje
Published: February 2019

In numerical modeling, dam break is one case that has its own challenges, because shock wave is found in the dam break modeling that usually provides a numerical instability. Usually, dam break problem is solved by Saint Venant equation using a finite difference method with artificial dissipation or Total Variation Diminishing (TVD) filter. But in this research, finite element method and the finite difference method are used. To verify the accuracy of the model, a comparison against the Stoker analytical method for dam break case was performed. Numerical modeling of dam break is required to find out the collapse area, thus it is used for determining mitigation that can be done in the area, related to dam safety. In numerical modeling, oscillation or numerical instability often occurs, for which special treatment is required to reduce or eliminate the oscillations. In this research, the treatment for that case is a Hansen filter for both methods. From the simulation result, it is found that Hansen filter is sensitive in reducing oscillation depending on the correction factor value and Δt that used. For dam break case, after filter applied, the value of Pearson Correlation Coefficient of Taylor Galerkin and Mac-Cormack methods are 0.999. The error rate for a Taylor Galerkin method are 0.118% at t = 3s and 0.123% at t = 10s. The error rate for Mac-Cormack method are 0.043% at t = 3s and 5.048% at t = 10s. From the comparison of the model, it can be concluded that Taylor Galerkin finite element method proved to be capable and more accurate in simulating dam break compared to Mac-Cormack finite difference method.
Comparative study on wave hindcasting using wind downscaling data at Bojong Salawe Beach
Authors: Oktariyanto Nugroho Eka , Arie Moniaga Benedictus , Suciaty Fitri , Chrysanti Asrini , Harlan Dhemi , Syahrial Badri Kusuma Muhammad
Published: February 2019

The wind data have a crucial role in shore construction engineering, but the availability data is commonly rare. Some research and recording station provide wind data with four times data record in a day. This research calculated the wave as resulted of the downscaled wind data from four times a day to twenty four times a day recording. The research done by comparing several data obtained from satellite record and land-station record. The results show similarity in wind velocity and dominance direction but have significant differences of wave height and the direction of wave from difference record locations.
Evaluation of the use of prefabricated bridge elements with Design for Manufacture and Assembly (DfMA) criteria
Authors: Purnomo Safaa Yan , Utomo Dwi Hatmoko Jati , Purwanggono Bambang
Published: February 2019

The increasing need for bridge infrastructure in Indonesia requires an efficient and lean construction process. The aim of this research to evaluate the use of precast concrete elements on bridges based on the Design for Manufacture and Assembly (DfMA) criteria. DfMA is a principle design that considers the process of manufacture and assembly components based on the following criteria, i.e., simplificity of design, number of components, standardization on elements or material and ease of handling. Analytical Hierarchy Process (AHP) is used to determine the weights for each criteria. Data were collected through observations on a bridge project, interviews with engineers and questionnaires. A typical girder and slab bridge is used as an object for DfMA-based evaluation. The results of evaluation design of prefabricated components to recommend some that are suitable for use in bridge construction. The last case study was taken to one of the bridge construction projects on the newly completed highway is done to identify the prefabricated components used. Bridge analysis and re-design are carried out with the DfMA concept, including costs incurred, resource scheduling and discussions of project risk. The results of analysis with simulation design giving efficiency 28,83% simplificity of design; 8,74% number of components and standardization on elements or materials; 25% ease of handling; 51,53% assembly time; 23,39% cost of work and 18,87% duration time. Finally, the level of risk of work received such as weather conditions and work safety is reduced. In closing, recommendations were given for further DfMA development.
Automation of visualization process for organizational and technological design solutions
Authors: Sinenko Sergei , Poznakhirko Tatiana , Obodnikov Vyacheslav
Published: February 2019

This article studies modern software packages used in drawing construction master plans and their elements. A special emphasis is placed on increasing the level of design works, improving their quality, and expanding the community of technically unskilled users. The article describes approaches to solving the task of visualization of organizational and technological solutions and gives a comparative analysis thereof. It presents a visualization diagram of an organizational and technological solution for the construction of a building. It also highlights the most promising direction in graphic modeling of a construction process for buildings and structures with visualization seen as the most objective solution to address the assigned task.
Indonesian contractors’ practices towards sustainable procurement principles for green building projects
Authors: Nugroho Sukardi Sapto , Abduh Muhamad
Published: February 2019

Sustainable practices in Indonesia’s construction industry have been considered and implemented in green building projects, even though they are not yet enforced by specific regulations on the practices, especially for procurement processes by the contractors. It is believed that the contractors’ procurement for selecting subcontractors and suppliers could boost the implementation of sustainability in construction industry since most construction companies deliver majority of their works through their supply chains. This paper presents the comparison between the sustainable procurement principles to the Indonesian contractors’ practices in procuring subcontractors and suppliers of their supply chains to support their green building projects. By so doing, the study would measure the compliance of sustainable procurement principles and practices by the Indonesian contractors. For this purpose, the ISO 20400, which is a flexible framework for sustainable procurement were used. The study was conducted using an integrated approach of grounded theory and qualitative data analysis based on a semi-structured interview to 3 large state-owned contractors in Indonesia that have been involved in green building projects. The results show that all contractors have the same level of sustainable procurement practices where the sustainable elements in its procurement process are still in the initiation stage and there are some sustainable procurement resources already existed in the practices that could support further implementation. This study provides the first comprehensive insight into the comparison between the initial sustainable procurement practices by Indonesia’s contractors to the ISO 20400. The contribution of this study could be used by Indonesian contractors to improve their sustainable procurement practices for green building projects or other sustainable projects in the future.
Islamic financing for infrastructure projects and its implementation barriers
Authors: Rarasati Ayomi , Trigunarsyah Bambang , Too Eric , Lamari Fiona , Bahwal Faiq
Published: February 2019

Research on Islamic project financing in infrastructure conducted predominantly in Islamic countries and developed countries showed its many benefits. This particular research focuses on Indonesia. As a developing country with a majority of Muslim population, it is reasonable to expect that Islamic project financing may also be a suitable option for financing alternatives in Indonesian infrastructure development. This paper aims to identify the barriers to implementing Islamic financing for infrastructure project development. A Delphi study was conducted to gather the views and opinions of an expert panel. The study found that the main barriers to implementing Islamic project financing are a lack of understanding of the Islamic project financing concept, a resistance to using Islamic finance, and investors’ behavior and characteristics, such as a profit-oriented mind-set and risk avoidance, which might affect the infrastructure stakeholders’ preference for using a sharia-compliant scheme.
Tracing New Safety Thinking Practices in Safety Investigation Reports
Authors: Karanikas Nektarios , Chionis Dimitrios
Published: February 2019

Modern safety thinking and models focus more on systemic factors rather than simple cause-effect attributions of unfavourable events on the behaviour of individual system actors. This study concludes previous research during which we had traced practices of new safety thinking practices (NSTPs) in aviation investigation reports by using an analysis framework that includes nine relevant approaches and three safety model types mentioned in the literature. In this paper, we present the application of the framework to 277 aviation reports which were published between 1999 and 2016 and were randomly selected from the online repositories of five aviation authorities. The results suggested that all NSTPs were traceable across the sample, thus followed by investigators, but at different extents. We also observed a very low degree of using systemic accident models. Statistical tests revealed differences amongst the five investigation authorities in half of the analysis framework items and no significant variation of frequencies over time apart from the Safety-II aspect. Although the findings of this study cannot be generalised due to the non-representative sample used, it can be assumed that the so-called new safety thinking has been already attempted since decades and that recent efforts to communicate and foster the corresponding aspects through research and educational means have not yet yielded the expected impact. The framework used in this study can be applied to any industry sector by using larger samples as a means to investigate attitudes of investigators towards safety thinking practices and respective reasons regardless of any labelling of the former as “old” and “new”. Although NSTPs are in the direction of enabling fairer and more in-depth analyses, when considering the inevitable constraints of investigations, it is more important to understand the perceived strengths and weaknesses of each approach from the viewpoint of practitioners rather than demonstrating a judgmental approach in favour or not of any investigation practice.
The AVAC-COM Communication Model and Taxonomy: Results from Application to Aviation Safety Events
Authors: Karanikas Nektarios , Passenier David
Published: February 2019

Communication problems are acknowledged as hazardous eventualities affecting operations negatively. However, a few systematic attempts have been made to understand the pattern of communication issues and their contribution to safety events. In this paper, we present the AVAC-COM communication model and taxonomy based on the cybernetics approach and a literature review. The model elements and taxonomy variables regard the actors, signals, coders, interference, direction and timing, predictability, decoders, and channels. To test the applicability and potential value of the AVAC-COM framework, we analysed 103 safety investigation reports from aviation published between 1997 and 2016 by the respective authorities of Canada, the United States, Australia, the United Kingdom and the Netherlands. The overall results of the 256 cases of communication flaws detected in the reports suggested that these regarded more frequently Human-Media and Human-Human interactions, verbal and local communications as well as unfamiliarity of the receivers with the messages transmitted. Further statistical tests revealed associations of the region, time period, event severity and operations type with various variables of the AVAC-COM taxonomy. Although the findings are only indicative, they showed the potential of the AVAC-COM model and taxonomy to be used to identify strong and weak communication elements and relationships in documented data such as investigation and hazard reports.