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  1. LOCAL SCOURING AROUND PILE AND CURVED CHANNEL Download Article

    Dantje K. Natakusumah, Dhemi Harlan and Sony Herdiansyah
    • Article Type: Research Article
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    • Pages (1-8)
    • No of Download = 428

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    One of the destructive water force is scouring due to obstruction or alteration of its flow. Understanding the process is crucially necessary to be able to predict and anticipate scouring. FVCOM model is used in this study to simulate scouring on the pile and curved channel. FVCOM model calibrated with a previous experimental study on straight channel case, modeled curved channel to reveal its capability to capture secondary flow phenomenon, and modeled flow with a pile on a curved channel to reveal its pattern. This study is intended to reveal the scouring pattern on the pile and curved channel. FVCOM model is based on the finite volume method to solve Navier Stokes hydrodynamics, Meyer Peter Muller sediment transports, and Exner bed updates equations. FVCOM model has successfully captured flow behavior around the pile and curved channels such as downflow on upstream of the pile, wake vortex on downstream of the pile, and secondary flow on the curved channel. Pile and curved channel caused scouring in each case. Together, they make a scouring phenomenon even more. This is well proven in FVCOM simulation as the pile on curved channel scoured deeper compared to those on straight one.

  2. SERVICEABILITY AND DUCTILITY OF PARTIALLY PRESTRESSED CONCRETE BEAMS UNDER LIMITED CYCLES OF REPEATED LOADING Download Article

    Nazar K. Oukaili and Mohammed M. Khattab
    • Article Type: Research Article
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    • Pages (9-15)
    • No of Download = 403

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    This paper involves the results of the study undertaken on the partially prestressed concrete beams with bonded prestressing steel subjected to limited cycles of repeated loading. The flexural behavior of partially prestressed concrete beams has been investigated through an experimental program involving testing six full-scale simply supported beams with a clear span of (3000) mm. The goal of this study was to investigate the effect of limited repeated loading cycles on strength and serviceability (cracking and deformability) of partially prestressed concrete beams. Accordingly, these beams were divided into two identical sets. The first set consisted of three beams, one of tension-controlled, the second of transition-controlled, and the last one is compression-controlled. These beams are tested under static loading and considered as controlled beams. They were subjected to four-point bending by using two symmetrical concentrated static loads up to destruction. The loads were applied at the middle third of the clear span length. The second set consisted of exactly the same three beams as in set one but they were subjected to ten cycles of the repeated load. The range of repeated load was between “0.4 to 0.6” of ultimate load produced from the static test. After the ten cycles, the load was released and then the beams were subjected to monotonic static test until failure. Readings were made for strains in nonprestressed and prestressed steel, midspan deflections, crack widths and crack spacing at different loading increments. Findings show that partially prestressed compression-controlled beams were less sensitive to the repeated loading.

  3. AXIAL BEHAVIOR OF RC COLUMNS RETROFITTED USING BAMBOO REINFORCED CONCRETE JACKET Download Article

    Ari Wibowo, Indradi Wijatmiko and Christin Remayanti Nainggolan
    • Article Type: Research Article
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    • Pages (16-23)
    • No of Download = 400

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    Weak or damaged reinforced concrete columns need to be retrofitted in order to increase the strength capacity and ductility. Concrete jacketing is one of the most common techniques adopted for such purpose due to its relatively simple and low-cost application. However, the dependency on steel reinforcement in its use is still high and with the sustainability issues that are getting more important nowadays, the idea of bamboo as a replacement for steel as reinforcing bars in the concrete jacketing method has been investigated in this experimental study. A group of short reinforced concrete column specimens with axial load failure state were then retrofitted with a variety of longitudinal and transversal bamboo reinforcement configurations of concrete jacketing and subjected to further compression axial load test. The axial load-displacement behavior, axial strength capacity, and collapse mechanisms were recorded and analyzed. The outcomes showed that bamboo reinforced concrete jacket perform satisfactorily by restoring the axial load capacity and increasing ductility of column specimens providing that the bamboo stirrups spacing was set closer than that of the original column.

  4. STUDY OF MODULUS ELASTICITY OF PVC COATED WELDED MESH FIBER CONCRETE Download Article

    Christin Remayanti Nainggolan, Indradi Wijatmiko and Ari Wibowo
    • Article Type: Research Article
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    • Pages (24-30)
    • No of Download = 380

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    Modulus elasticity is an important parameter that shows the ability of concrete to deform elastically. Data analysis to obtain that value of modulus elasticity can be done with several approaches. To compare some of these approaches and to study the effect of fiber to the modulus elasticity of concrete, an experiment on the addition of PVC coated welded wire mesh fiber to the concrete mixture has been conducted. The specimen in this experiment was a cylindrical specimen with a diameter of 150 mm and height 300 mm. There are 3 variations in this experiment : (1) variations in the fraction of percentage of wire fiber; (2) fiber’s length variation and (3) length interlocking variation. Extensometer was installed onto the specimens to measure stress-strain of concrete while the compressive strength was conducted. The data obtained and then analyzed. The result of the analysis showed that the higher the fiber’s fraction added to the concrete mixture, the greater the modulus elasticity resulted. However, PVC coated welded mesh fiber concrete has a less value of modulus elasticity when it compared with normal concrete due to the slip effect between fiber and concrete. Furthermore, there are some approaches with good agreement and some indifferent results.

  5. STRENGTH CHARACTERISTICS OF WASTED SOFT DRINKS CAN AS FIBER REINFORCEMENT IN LIGHTWEIGHT CONCRETE Download Article

    Indradi Wijatmiko, Ari Wibowo and Christin Remayanti Nainggolan
    • Article Type: Research Article
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    • Pages (31-36)
    • No of Download = 370

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    Nowadays the problems of lightweight concrete flexural strength have been approached by adding fiber to the mixture. Meanwhile, waste materials are continuously produced as a result of the modern industry. This paper aims to increase the strength characteristic of both compressive and flexural lightweight concrete by introducing wasted soft-drink cans as fiber reinforced. A comprehensive study has been conducted to investigate the optimal amount of fiber fractions and the effect of fiber shape to the concrete mechanical strength. This study cleared the effect of various fractions (10%, 15% and 20% by volume of concrete), followed by two types of fiber shape (hooked and clipped) to the lightweight concrete compressive and split tensile strength. The experimental results of cylindrical lightweight concrete were compared to the normal lightweight concrete. The result showed that the introduction of 10% of fiber performed in higher tensile strength with an increase of 23%, while the hooked shape of fiber increased the compressive strength by more than 40%. It can be concluded that the introduction of waste recycle tin increased the mechanical properties of normal lightweight concrete, however further study can be performed to effectively increase the strength characteristics.

  6. DAMAGE LEVEL PREDICTION OF MULTI-STORY STEEL STRUCTURE IN SUMATRA USING BACKPROPAGATION NEURAL NETWORK Download Article

    Reni Suryanita, Harnedi Maizir, Ismeddiyanto, Vindi Trisatria and Raihan Arditama
    • Article Type: Research Article
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    • Pages (37-42)
    • No of Download = 350

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    Sumatra is one of the Indonesia islands that is prone to earthquakes both tectonic and volcanic. The research aims to predict the damage level of a multi-story steel structure due to the earthquake in Sumatra Island using the Backpropagation Neural Network (BPNN). The study used the steel structure building that received earthquake loads from ten capital cities of the province on Sumatra Island. The structure analysis used the finite element software while the BPNN method used the MATLAB Programming. The input data were the responses of the structure such as displacement, velocity, and acceleration while the output was damage level of the steel structure model. The model of BPNN has the potential accuracy to predict the damage level of steel structural more than 95%. According to the simulation result, 98,5% data could be predicted correctly by the BPNN method, and the best Mean Squared Error (MSE) is 0.028. These results have shown that BPNN can predict the damage level of multi-story steel structure in all the capital cities of the province on Sumatra Island.

  7. HYDROLOGICAL AND NITRATE LOADING MODELING IN LAM TAKONGWATERSHED, THAILAND Download Article

    Chau Ngoc Tran and Chatpet Yossapol
    • Article Type: Research Article
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    • Pages (43-48)
    • No of Download = 345

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    Water pollution is largely associated with the growth of agriculture, urbanization, and industrialization. By the year 2016, the quality of significant surface water sources in Thailand has been evaluated and categorized as 34% good quality, 46% fair quality and 20% poor quality. According to the Pollution Control Department of Thailand, the lower Lam Takong river, one of the critical watersheds of Thailand, is considered to have a poor water quality. In Lam Takong watershed, non-point sources area approximately covered 89% of the total area, those sources became the significant contributors of water pollutants, particularly nutrients to the Lam Takong watershed. Plus, water quality researches of the watershed were carried out with many different watershed models, but the SWAT model has not been applied to allot the pollutant loading from diffuse sources. Therefore, the main objective of this study is to apply the SWAT model to simulate flow and nitrate from 2007 to 2017, and allocate NO3- loading in upstream is lower than downstream of the Lam Takong watershed. The R2 values are 0.69 in upstream and 0.64 in downstream of Lam Takong. The results of the study can be a useful tool for the management of surface water resources in the Lam Takong watershed.

  8. LIFE CYCLE IMPACT ASSESSMENT OF NEW GROUND MATERIAL AND EMBANKMENT CONSTRUCTION METHODS CONSIDERING RECYCLING Download Article

    Hideyuki Ito, Kento Aimono and Takahiro Fujii
    • Article Type: Research Article
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    • Pages (49-55)
    • No of Download = 340

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    In Japan, the conventional cut-and-fill method is often used in banking construction methods. However, this construction method is pointed out that it causes land subsidence and/or landslide in soft ground. For solving these problems, various new construction methods using the ground materials such as EPS (styrofoam), recycled foamed waste glass and expanded polystyrene beads have been developed as a new lightweight and workable composite geomaterials. These new construction methods are believed to be effective for construction on soft ground and landslide-prone areas. In existing researches of this field, they aimed to identify areas for improvement and the problems associated with the use of these new ground materials. However, there are few types of research that focused on negative impacts on land use, by exhausting air pollution and GHGs (Green House Gases) with recycling from the perspective of the environmental economics field. Thus, in this research, we compared conventional cut-and-fill method and some new ground materials such as the expanded polystyrol construction method using the new EPS geomaterial, the lightweight embankment construction method with EPS beads and the foamed waste glass construction method using embankment material with recycled waste by analyzing the negative impacts to land use considered ecosystem services and life cycle cost (LCC) including external cost by emissions of GHGs and air pollutants such as SOx and NOx using life cycle impact assessment analysis.

  9. SIMULATION SEA SURFACE TEMPERATURE OVER GULF OF THAILAND BY USING ROMS MODEL Download Article

    Usa Humphries and Pramet Kaewmesri
    • Article Type: Research Article
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    • Pages (56-61)
    • No of Download = 321

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    The Gulf of Thailand and neighbor area was studied using the Regional Oceanic Model System (ROMS). The horizontal resolution and vertical levels were 10 km × 10 km and 40 layers respectively. The domain situated between longitudes 95o E to 109o E and latitudes 0o N to 17o N. The initial and boundary conditions was used in this study that includes potential temperature, salinity, u-component of current, v-component of current and sea surface height relative to geoid from NCEP-CFSV2 data. The simulation dates were the end of month of May, June and July. Discussion from the literature review is found that the Sea Surface Temperature (SST) is a very important factor in the ocean and coupled atmosphere-ocean interaction. In this study used Generic Length Scale (GLS) vertical mixing method to simulate SST. The results from the model simulation are compared with spatial pattern with grids global observation data from the Optimum Interpolation Sea Surface Temperature (OISST) observation data. Overall the ROMS model can capture trend of SST pattern similarly OISST observation especially June 30 and July 31, 2018. In future work will simulate monthly mean SST from ROMS model and will compare with OISST monthly observation data in spatial pattern and statistical.

  10. DEVELOPMENT OF DROUGHT RISK ANALYSIS PLATFORM USING MULTIPLE SATELLITE SENSORS Download Article

    Mongkol Raksapatcharawong and Watcharee Veerakachen
    • Article Type: Research Article
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    • Pages (62-69)
    • No of Download = 311

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    Drought, due to climate change, has in recent years become more severe. Capability to monitor drought conditions and to assess drought risk is essential to the development of an effective drought adaptation plan, especially for an agricultural country like Thailand. Current drought monitoring is provided by separate indices such as Standardized Precipitation Index (SPI), Soil Moisture Index (SMI) and Moisture Available Index (MAI), calculated from weather station datasets which are not easily comprehensible to users. This research develops a countrywide integrated satellite-based drought model consisting of three parameters: accumulated estimated rainfall generated from FY-2E satellite data, the difference in Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) generated from MODIS. A simple drought hazard is introduced as a multiple linear regression model (R2=0.795) of these satellite products, calibrated with daily soil moisture measurements in 2015. Consequently, drought conditions are represented by the Drought Hazard Index (DHI) whose assigned integer values are from –3 (extremely dry) to +3 (extremely wet), according to the defined thresholds (presently at 0.05, 0.15, 0.30, 0.70, 0.80, and 0.95) of the cumulative distribution function (CDF) of drought hazard values. The model is validated with 426 countrywide drought situations announced by the Department of Disaster Prevention and Mitigation (DDPM), during the drought season of 2016, yielding a 0.96 probability of detection. Subsequently, the model outputs are processed with relevant GIS data, which are agricultural and irrigation areas to represent drought exposure and vulnerability respectively, to generate a drought risk map for further analysis and planning. This platform can benefit not only policymakers but also the farmers themselves.

  11. ESTIMATION OF SEDIMENTATION RATE AND FRESH-SALINE ENVIRONMENT IN A COASTAL ALLUVIAL PLAIN, USING BORING CORES OF ALLUVIUM IN THE CENTRAL PART AREA OF SETO INLAND SEA, JAPAN Download Article

    Tohru Takeuchi, Shin-ichi Onodera, Kazuhiro Yamaguchi and Koichi Kitaoka
    • Article Type: Research Article
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    • Pages (70-75)
    • No of Download = 301

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    To estimate the sedimentary environment between the last glacial stage and the Holocene epoch of an enclosed sea in the Okayama Plain, which constitutes a portion of the Seto Inland Sea coast, we collected 4 boring cores at depths of 6 to 19 m, performed radiocarbon dating of the organic matter contained in the clay, identified the volcanic glass from the Aira Caldera eruption, and measured the electrical conductivity of the pore water. Based on these dating analyses, it was evident that the Holocene clay layer that is widely distributed throughout the Okayama Plain had already accumulated prior to 10,000 years ago. In addition, the different hardness and the presence of Aira volcanic ash in the clay layer indicated the sedimentation since Pleistocene. Because the sea level at the time was lower than this clay sedimentation level, those facts suggest freshwater lakes existed in the Okayama Plain which was dammed up by the shallower granite basement in the mouth of Kojima Bay. Based on the long clay core and date for the last 30,000 years, the sedimentation rates were estimated to be 0.18 mm/ year before 8,100 years ago and 1.19 mm/year for the last 8,100 years, respectively. In the sea water rising after 7,000 years ago, the sea level exceeded the dam and the bay became a saline condition.

  12. ULTIMATE VERTICAL BEARING CAPACITY OF CLAYEY SQUEEZE BREAKDOWN USING RIGID-PLASTIC FINITE ELEMENT METHOD Download Article

    Kazuhiro Kaneda, Masamichi Aoki, Tomohiro Tanikawa and Satoru Ohtsuka
    • Article Type: Research Article
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    • Pages (76-82)
    • No of Download = 302

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    The relations of ultimate bearing capacity for foundations are specified in the guideline published by the Architectural Institute of Japan for design of building foundations. The rigid-plastic finite element method developed by Tamura and Ohtsuka has been employed to estimate the ultimate bearing capacity of footings. The characteristic of this method is that, in contrast to deformation analysis, it applies limited soil constants; only the strength parameters, such as cohesion and friction angle, are used since the method deals with the limit state directly by disregarding the deformation of the building and ground. In this study, a series of rigid plastic finite element analyses were performed to compare the ultimate bearing capacities of spread foundation for clayey squeeze breakdown obtained by simulations and the formulae of the Architectural Institute of Japan. The change in the failure mode of the ground was discussed considering the geometrical ratio between the width of the footing and the surface clay layer. In addition, inclined load was considered for clayey squeeze breakdown. The applicability of rigid plastic FEM to the assessment of ultimate vertical bearing capacity of clayey squeeze breakdown was demonstrated.

  13. TOPOGRAPHIC CONTROL ON GROUNDWATER FLOW IN CENTRAL OF HARD WATER AREA, WEST PROGO HILLS, INDONESIA Download Article

    T. Listyani R.A., Nana Sulaksana, Boy Yoseph CSSSA and Adjat Sudradjat
    • Article Type: Research Article
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    • Pages (83-89)
    • No of Download = 279

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    West Progo Hills is one of some hard water area in Indonesia. It doesn’t belong to the groundwater basin because it is difficult to get groundwater. Groundwater can be found in some places with a random point. Dug wells are usually found in the narrow area, as well as springs. By hydrogeological as well as hydro isotope approaches, this research wants to know about groundwater potential in West Progo Hills especially at the central part of it. The groundwater mapping has been done at Girimulyo - Kaligesing and surrounding area, to get some geologic data, water table measurement, and geomorphological data. The result of the research shows that the groundwater table usually follows the local topography. Groundwater table ranges 0.9 – 8 m below surface, it means shallow groundwater table. Dug wells are only locally found, as well as springs. Some springs often found at break of slope, it means that they’re controlled by topography. Based on the groundwater table from dug wells data, groundwater is conformable to the topographic condition. The relationship between elevation and groundwater table gives the correlation coefficient (r) as much as 99.99%. It means that relief is followed by the groundwater level. It can be concluded that relief has a strong correlation with shallow groundwater in the research area, although the stable isotopic data doesn’t support the altitude effect of it. Groundwater flows from high to low lands, such as the upper slope of hills to valleys.

  14. DESIGN OF IMPROVED LIME EXPANSIVE SOIL FOR EMBANKMENT OF FLEXIBLE PAVEMENT Download Article

    Yulvi Zaika and Eko Andi Suryo
    • Article Type: Research Article
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    • Pages (90-95)
    • No of Download = 275

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    The problem of the pavement structure on an expansive subgrade has to be found in some area which the reason the road surface will failure. Expansive soil experiences periodic swelling and shrinkage during the alternate wet and dry environments. The lime as the additive substance can reduce the swell potential and increase the bearing capacity of expansive soil was well known. In this study, the expansive natural soil and the improved lime soil have been used as landfill for subgrade of the pavement structure. Numerical modeling of flexible pavement constructed on expansive soil would apply for investigate settlement and strain to estimate failure which is always occurring. Based on FEM analysis using a computer program, the results show that the application for embankment with a height of 5m with the traffic load is considered a static load, resulting in a reduction in the potential damage where compressive strain occurs on the road surface under traffic load. The lime also reduced the total settlement.

  15. FUZZY MULTI-ATTRIBUTE DECISION MAKING FOR THE SELECTION OF A SUITABLE RAILWAY TRACK MAINTENANCE PLAN: A CASE STUDY IN THAILAND Download Article

    Thawatchai Phanyakit and Thaned Satiennam
    • Article Type: Research Article
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    • Pages (96-104)
    • No of Download = 269

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    Degradation of infrastructure has affected service quality; in other words, the rail freight transportation rate has been considerably low at only 2%. As a result, for the purposes of safety and high-reliability levels in infrastructure, several organizations have conducted serious research on the interesting topic of railway track degradation. As the focus of the present study was degradation factors, the Fuzzy Multi-Attribute Decision Making Method (FMADM) was used to analyze railway track defects and degradation and to select a maintenance plan schedule. Related research and literature were reviewed, and a questionnaire was designed to collect opinions from experts working for the State Railway of Thailand (SRT). The experts prioritized risk levels likely to result in the worst breaks or damage, using UIC defect codes. These consisted of transverse break defects without apparent origin (code 200) with the highest level of impact and relative weight of 0.396, followed by star-cracking of fish bolt holes (code 135) with a relative weight of 0.276 and transverse cracking of profile thermite welding (code 421) with a weight of 0.187. The least severe impact was said to come from horizontal cracking at web-head (code 1321) with a relative weight of 0.142. Analysis results based on FMADM indicated that the railway track structure replacement plan, as considered by the experts, was better than the railway track rehabilitation plan, as shown by their importance weights of 0.575 and 0.425, respectively.

  16. QUICK ASSESSMENT PROCEDURES FOR TWO STORIES BUILDING BASED ON NUMERICAL SIMULATION RESULTS Download Article

    Febrin Anas Ismail, Abdul Hakam, M. Maisaquddus Hape and M. Sofian Asmirza
    • Article Type: Research Article
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    • Pages (105-109)
    • No of Download = 257

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    Quick assessment is one of an important step in emergency response following an earthquake. This step is mainly purposed to estimate the financial lost based on the building damage criteria. The result of a quick assessment is also needed to determine whether the damaged building can be repaired and reused or not. There are three damage levels which are classified based on the building conditions after the earthquake. Based on the experience, there is a time constraint in conducting the building assessment. Then a quick-correct method is very important to accomplish the task in the limited time. Base on the series of numerical simulation, the quick assessment procedure is proposed in this study. The structural elements that need to be checked in the quick assessment are including column, beam, plate, and foundation. The numerical result was conducted for some two stories buildings with minimum reinforcement on those structural members. The minimum reinforcement requirements are base on Indonesia code SNI-1736-2012. The critical point of every structural component to be checked, especially columns, is discussed here.

  17. MICROBIAL INDUCED SLOPE SURFACE STABILIZATION USING INDUSTRIAL-GRADE CHEMICALS: A PRELIMINARY LABORATORY STUDY Download Article

    Sivakumar Gowthaman, Shumpei Mitsuyama, Kazunori Nakashima, Masahiro Komatsu and Satoru Kawasaki
    • Article Type: Research Article
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    • Pages (110-116)
    • No of Download = 414

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    One of the promising soil improvement techniques that have recently gained increased attention in Geotechnical and Civil Engineering is microbial induced carbonate precipitation (MICP). The MICP is mediated by ureolytic bacteria through a chain of biochemical reactions which lead to the formation of calcium carbonate cement in soil matrix and persuades the substantial bonds between the soil particles. The study presented herein focuses on surficial stabilization of slope soil (Hokkaido, Japan) by mediating industrial-grade chemicals through two different scales of preliminary laboratory investigations: small-scale columns and bench-scale slopes. Locally isolated Psychrobacillus sp. was cultivated in both industrial-grade media (beer yeast) and laboratory-grade media (NH4-YE: tris-buffer, ammonium sulfate and yeast extract), and the urease activities were compared. The results showed that the cultivation of bacteria in beer yeast resulted in higher urease activity (0.9 U/mL) compared to that in conventional laboratory media (0.4 U/mL). Also, UCS of the specimen treated using industrial-grade chemicals (urea fertilizer, beer yeast and snow melting reagent) was about two times higher than the specimen treated using conventional laboratory-grade chemicals (urea, CaCl2 and nutrient broth). The benchtop-scale test revealed that the highest surface strength (UCS of 1.02 MPa) was achieved while treating the soil by 0.5 M cementation solution at 30ºC. Sets of colorimeter measurements were undertaken on treated slope models to compare precipitation profile at different locations. These findings suggest that industrial-grade chemicals can contribute as potential candidates in MICP applications from the perspective of cost reduction.

  18. EFFECT OF CURING TEMPERATURE ON THE DEVELOPMENT OF HARD STRUCTURE OF ALKALI-ACTIVATED SOIL Download Article

    Lokmane Abdeldjouad, Afshin Asadi, Bujang B.K.Huat, Mohd Saleh Jaafar, Wisam Dheyab and Ahmed Giuma Elkhebu
    • Article Type: Research Article
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    • Pages (117-123)
    • No of Download = 383

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    This study is directed to the feasibility of usage of palm oil fuel ash (POFA) as a precursor of alkaline activation reactions which made by potassium hydroxide in order to stabilize the soil and improve its expediency for the different case of construction. The effect of duration and temperature of curing, for the alkaline activation process, on the Unconfined Compression Strength (UCS) of the soil-POFA mixture is important in enhancing the treated soil properties. Use of 30, 50, and 100°C of heating affected the UCS of the soil mixture. The highest strengths were obtained at 100°C for the alkali activation process. Microstructural analysis using The Brunauer–Emmett–Teller (BET) and Infrared spectrometric analysis (FTIR) shows the benefits of alkaline activation in terms of decreasing the duration of the alkaline process. The pore distribution analysis showed a trend to rise pore size volume with increasing temperature, which affects the mechanical characteristics. This was due to the fastest crystallization processes which account for strength gain after a short period of heating. It has been also presented the opportunity of observing the alkaline activation process by FTIR Spectra. This paper highlights a more environmentally friendly procedure of stabilizing soils compared with the traditional binders such as cement and lime.

  19. SOME INSIGHT INTO DIRECT OBSERVATION OF HYDROLOGICAL PARAMETERS IN PEATLAND AREA OF THE SOUTH SUMATERA Download Article

    Muhammad Irfan, Wijaya Mardiansyah, M. Yusup Nur Khakim, Menik Ariani, Albert Sulaiman and Iskhaq Iskandar
    • Article Type: Research Article
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    • Pages (124-129)
    • No of Download = 361

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    An integrated observation system so-called SEnsory data transmission Service Assisted by Midori Engineering laboratory (SESAME) has been deployed in the peatland area of the South Sumatera Province, Indonesia since June 2017. The system directly measures and records the groundwater level, soil moisture, skin temperature and rainfall in the peatland area. In this study, we used data recorded at four locations, two sensors located at the Peatland Hydrological Unit (PHU) of the Saleh River and the other two are located at the PHU of the Lumpur River. Data for a period of 17 June 2017 to 31 March 2018 were used to evaluate the characteristics of hydrology and climatology of the peatland in the South Sumatera. It was found that a high rainfall is associated with low skin temperature, high soil moisture, and shallow groundwater level. Furthermore, it was found that the observed groundwater level is significantly correlated with the observed rainfall. Interestingly, the adjusted groundwater level from TRMM rainfall shows a significant correlation with the number of hotspots during dry-season (July-October). Therefore, we may use the observed rainfall for peat fire early morning.

  20. RELIABILITY ASSESSMENT OF WOODEN TRUSSES OF A HISTORICAL SCHOOL Download Article

    Alvin G. Quizon and Lessandro Estelito O. Garciano
    • Article Type: Research Article
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    • Pages (130-135)
    • No of Download = 336

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    Records show that the National Structural Code of the Philippines (NSCP) wind load requirement increases over time. Increase wind velocity from stronger typhoon events translates to additional wind pressure. These changes pose a threat to existing historical structures such as Gabaldon schools which were designed and constructed more than a hundred years ago. The Department of Education (DepEd) continues its efforts in its conservation. Reliability assessment of wooden trusses is necessary to check if there is a need to retrofit to maintain its function and preserve its significance in the country’s history. In the analysis of the roof trusses affected directly by wind load, all loads are considered as constant except for the uniformly distributed wind load. These constant loads serve as the initial stresses acting within the truss members. Uniformly distributed wind load produces additional stress on top of the initial stress. Any changes in the amount of wind load constitute proportionally to changes in the stresses of truss members. A commercially available software makes it easier to identify corresponding stresses for several amounts of wind load. Using a spreadsheet, a simple graphical model and equation are generated expressing the relationship between wind velocities against axial force, shear force and bending moment. Mechanical properties of wood establish the limits of its strength in terms of wind velocity using the graphical model and equation obtained. The result reveals the limitation of each truss member in terms of wind velocity that even ordinary people can now easily perceived and understood.

  21. DEVELOPMENT OF ASSESSMENT FOR POTENTIALLY TOXIC ELEMENT CONTAMINATION INDICATOR IN CLOSED LANDFILLS AND PROSPECTIVE GEOSTATISTICAL ANALYSIS Download Article

    Azizi Abu Bakar, Minoru Yoneda, Nguyen Thi Thuong and Noor Zalina Mahmood
    • Article Type: Research Article
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    • Pages (136-143)
    • No of Download = 321

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    Post-closure management of landfill in Malaysia does not include assessment of the contaminant level in abiotic and biotic factors that inhabit the aged topsoil of closed landfills. Considering the bioaccumulation effect in the ecosystem, post-closure classification with the status of contaminant concentration below the permitted level does not promise safe closure to the ecosystem as time passes. Thus, substantial and constant qualitative analysis of contaminant concentration needs to be developed for sustainable management of landfill post-closure. In this work, heavy metals in common constituents (abiotic and biotic factors) of closed landfills were selected; that is, soil, stagnant water, and common communities of plant species in closed landfills in Selangor, both sanitary and non-sanitary, were studied. The results of the analysis demonstrated that the concentration of Cd was not detected in the soil of both landfills but the highest concentration was present in the leaves of Ageratum conyzoides compared to other plant species at both study sites. A parallel situation was discovered for the non-detection of Cd concentration in stagnant water at Ampar Tenang landfill, but the leaves of A. conyzoides contained this element. The sensitivity and affinity of A. conyzoides for accumulating heavy metals in this study were revealed particularly for Cd. Hence, this study suggests the use of A. conyzoides as a promising trace metals contamination indicator for closed urban landfills. Additionally, Guess-Field Kriging is believed to be a useful geostatistical tool to interpolate potential contamination area by utilising the abiotic and biotic factors as assistant variable to the target variable i.e. soil.

  22. ASSESSING THE ULTIMATE BEARING CAPACITY OF FOOTING IN A TWO-LAYERED CLAYEY SOIL SYSTEM USING THE RIGID PLASTIC FINITE ELEMENT METHOD Download Article

    Kazuhiro Kaneda, Masamichi Aoki and Satoru Ohtsuka
    • Article Type: Research Article
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    • Pages (144-150)
    • No of Download = 407

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    Ultimate bearing capacity formulae for foundations are specified in the guideline published by the Architectural Institute of Japan for the design of building foundations. The rigid plastic finite element method was developed by Tamura and Ohtsuka to estimate the ultimate bearing capacity of footing. Unlike deformation analysis, this method employs limited soil constants; it uses only the strength parameters of cohesion c and friction angle φ as it considers the limit state directly and disregards the deformation of the building and ground. A series of rigid plastic finite element analyses were conducted to compare the ultimate vertical and inclined bearing capacities of spread foundations between the simulation results and the theoretical formula for a two-layered clayey soil system. The change in the failure mode of the ground was discussed using the geometrical ratio between the width of the footing and the height of the surface layer. The strength ratio of the surface and second ground layer was clearly shown to affect the formation of failure mode. The applicability of the rigid plastic finite element method for the assessment of the ultimate bearing capacity of a two-layered clayey soil system was successfully demonstrated.

  23. SETTLEMENT BEHAVIOUR OF PARIT NIPAH PEAT UNDER STATIC EMBANKMENT Download Article

    Adnan Zainorabidin, Mohamad Niizar Abdurahman, Azman Kassim, Mohd Firdaus Md Dan Azlan, Siti Nooraiin Razali and Engku Shahrulerizal Engku Ab Rahman
    • Article Type: Research Article
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    • Pages (151-155)
    • No of Download = 210

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    Peat is considered as a very challenging soil when constructing any structure. It’s known with high compressibility, high moisture content, low shear strength and long term settlement when subjected to load. These characteristics always posed constant problem for sustainable construction on peat. This study aims to investigate the settlement behaviour of peat fortified with concrete slab under embankment loading through full scale testing at Parit Nipah, Johor, Malaysia. The peat is categorized as hemic with moisture content greater than 500%. A concrete raft sized 3.6 m x 3.6 m with thickness of 150 mm was built on the site. The 3.6 m x 3.6 m slab was subjected to non-uniform loading. Results indicated that the installation of slab on peat able to reduce the settlement of peat under embankment loading. The study shows potential to mitigate or reduce long term post construction settlement on peaty ground.

  24. CONSTRUCTION OF EARTH FILL STRUCTURE FOR SMALL FARM POND BY USING BHUTANESE TRADITIONAL WALL MAKING METHOD Download Article

    Ueno Kazuhiro, Natsuka Isamu, Sato Shushi, Onjo Norio, Karma Tshethar and Kelzang Tenzin
    • Article Type: Research Article
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    • Pages (156-161)
    • No of Download = 313

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    The Kingdom of Bhutan has mountains as high as 7,000 meters height at the east end of the Himalayas and the semitropical region at an altitude of 100 meters in its south area. Because of its precipitous terrain, stable supply of water for irrigation is difficult without efficient water supply system such as reservoirs, pipelines and so on. Based on the results of preliminary field investigations, existing reservoirs in the Kingdom of Bhutan often have structural problems in its body and foundation. To contribute to an increase in agricultural production in the Kingdom of Bhutan through the development of construction techniques for reservoirs, an earth fill structure for a small farm pond was suggested and constructed in 2015. In this construction, the Rammed earth method, which is well known as a Bhutanese traditional wall making method, was applied as a compaction technique of soil. Authors conducted a follow-up of the earth fill structure in September 2017 to confirm the performance of the wall making method as a construction technique for reservoirs. Based on the results of the portable dynamic cone penetration tests, it is supposed that this rammed earth method couldn’t achieve sufficient compaction energy for construction of earth fill structures for reservoirs because observed N values were comparatively small compared with that obtained from embankments constructed by modern compaction techniques. Therefore, in the construction of earth fill structures for farm pond by utilizing the rammed earth method, improvement in the compaction technique should be considered.

  25. A PREDICTION METHOD FOR LONG-TERM SETTLEMENT OF HIGLY ORGANIC SOFT SOIL Download Article

    Shoji Kamao
    • Article Type: Research Article
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    • Pages (162-169)
    • No of Download = 397

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    One of the prediction method of the long-term settlement of soft clay is to predict it by defining the linear slope of the latter half of the s-log t curve, as the rate of secondary consolidation. This method has some disadvantages, because the slope of the straight line is depending on how to set the origin of elapsed logarithmic time, and how to determine the initial thickness of soil layer, and so on. The author carried out a series of laboratory experiments using oedometer apparatus against some kinds of highly organic soil and one silty clay which were sampled in Japan. From the experimental results, the author proposed a prediction method for long-term settlement of highly organic soil based on the isotache theory using natural strain which can be used conveniently by eliminating previous problems. To confirm the applicability of the proposed prediction method, some field measurement data were used, constructed in Japan. They were good correlations, and the applicability of proposed method was proved in this study.

  26. CORAL REEFS DEGRADATION PATTERN AND ITS EXPOSURE TOWARDS CLIMATE CHANGE IN BUNAKEN NATIONAL PARK Download Article

    Nafil Rabbani Attamimi and Ratna Saraswati
    • Article Type: Research Article
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    • Pages (170-175)
    • No of Download = 266

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    Coral reef is one of many shallow-water ecosystems that are found in Bunaken National park. The coral reefs ecosystem in Bunaken National Park are threatened by the impact of climate change, such as rising seawater temperature, Change in Salinity, and increase extreme meteorological events. This study will address the coral reefs condition and its pattern in Bunaken National Park, how are the water condition in Bunaken National Park changes in the timespan of 2002-2017, and what are the relations between the degradation pattern of the coral reefs and the seawater condition as an exposure towards the ecosystem Climate change in the context of this study is based on oceanographic variables such as sea surface temperature and seawater salinity. The methods that are used in this study is through meta-descriptive analysis to determine the exposure of the coral reefs, spatial-descriptive analysis to relate between climate change and coral reef conditions. The results showed that the degradation conditions of coral reefs from 2002 to 2013 have decreased, but the condition of the degraded coral reefs has increased by 2017. Based on the analysis of the conditions of the exposure and coral reefs show that there is a correlation between the two.

  27. DEVELOPMENT OF THE COMPUTER PROGRAM OF CALCULATION OF CONCRETE BORED PILES IN SOIL GROUND OF ASTANA CITY Download Article

    Talal Awwad, Turlybek Mussabayev, Assel Tulebekova and Atogali Jumabayev
    • Article Type: Research Article
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    • Pages (176-182)
    • No of Download = 238

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    The current calculating theories of massive constructions are based on the simplified models without consideration of factors settlement as nonhomogeneous environments interaction, the interacting environments nonlinearity or considering them separately and conditionally. Therefore, equivalent numerical model designing of bored piles interaction with the soil mass and designing of a nonlinear technique of numerical calculation of similar systems on its basis is a modern and relevant task, which is an effective tool for a number of relevant geotechnical tasks solutions. The calculation of reinforced concrete bored pile with the real diagrams of a pile material deformation and surrounding rock massif has been presented in the article. The computer program allows receiving the strain-stress state of a pile and the surrounded massif as one heterogeneous body. New calculation approaches of the reinforced concrete bored pile can be used in the standards modernization when transferring from the regulatory framework of Kazakhstan to Euro code according to the reform concept.

  28. CHARACTERIZATION ALKALI-ACTIVATED MORTAR MADE FROM FLY ASH AND SANDBLASTING Download Article

    Yuyun Tajunnisa, Ridho Bayuaji, Nur Ahmad Husin, Yosi Noviari Wibowo and Mitsuhiro Shigeishi
    • Article Type: Research Article
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    • Pages (183-189)
    • No of Download = 398

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    This research is to find out the contribution of waste energy utilization in Indonesia as a binding agent of alkali-activated mortar. In a previous study, researchers investigated mortar made from class F fly ash/GGBFS/micro-silica in Japan. The inclusion of GGBFS is to shorten/normalize the setting time and micro-silica is to improve mortar performance. This research is then continued by using abundant waste material in Indonesia, namely class C fly ash, by making cubic mortar specimens. Setting time of class C fly ash paste from Indonesia is very fast, in contrast to that of class F fly ash paste from Japan. Sandblasting as abundant waste material in Indonesia is substituted to class C fly ash to lengthen the setting time of paste and to improve standard deviation of a compressive test of mortar specimens. On the other hand, the addition of sandblasting waste has a negative effect, because it reduces a compressive strength of mortar specimens.

  29. A POLICY MODEL OF ADAPTATION MITIGATION AND SOCIAL RISKS THE VOLCANO ERUPTION DISASTER OF SINABUNG IN KARO REGENCY - INDONESIA Download Article

    Dedi Hermon, Ganefri, Erianjoni, Indang Dewata, Paus Iskarni and Alexander Syam
    • Article Type: Research Article
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    • Pages (190-196)
    • No of Download = 377

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    The purpose of this research was to determine the level of volcano eruption risk and compile a disaster risk mitigation model for the Sinabung volcano eruption. Analysis technique of volcano eruption disaster risk of Sinabung uses scoring techniques for all indicators. The volcano eruption disaster risk of Sinabung refers to eruption hazard level, vulnerability level, and disaster prevention capacity index. The level of volcano eruption hazard and vulnerability of Sinabung volcano was analyzed by GIS approach using ArcGIS 10.1 software, based on units of sub-district administration. The capacity index was analyzed based on the Hyogo Framework for Action-HFA 2005-2015. While the disaster mitigation and policy model of adaptation of volcano eruption Sinabung were analyzed with FGD and AHP. The level of volcano eruption disaster risk of Sinabung is high > 49 (614). As for the mitigation model of the eruption risk of Sinabung volcano and model of adaptation policy based on alternative priorities for disaster risk reduction has 4 main priorities, i.e: 1) Relocation for identify, assess and monitor of disaster risk and implement an early warning system; 2) Utilize of knowledge, innovation and education to build a culture of safety and resilience at all levels; 3) Make of disaster risk reduction a priority of national and region implemented through strong institutions; and 4) the reducing of underlying factors that increase disaster risk.

  30. RELIABILITY OF ALKALI-ACTIVATED AND PORTLAND CEMENT MORTAR UNDER COMPRESSIVE TEST BY ACOUSTIC EMISSION Download Article

    Yuyun Tajunnisa, Mitsuhiro Shigeishi, Ridho Bayuaji and Muhammad Sigit Darmawan
    • Article Type: Research Article
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    • Pages (197-203)
    • No of Download = 224

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    Alkali-activated materials or geopolymer technology is one of the material innovations that can provide several benefits by reducing the use of Portland cement. The source of precursor materials come from industrial by-products. This study investigated the reliability failure of seven-variation of alkali-activated fly ash/slag/micro-silica mortar (AAM) and one-type of Portland Cement (PC) mortar. Compressive strength test accompanied by acoustic emission is used to characterize cylindrical mortar specimens. Examination of fracture distribution according to stress level until final failure was then performed. The compressive strength of four-type of alkali-activated mortar AAM (AAM-IV, V, VI, and VII) at 14 and 28 days shows a slight strength increase, 61.9 to 63.6 MPa, 62.3 to 65.6 MPa, 64.8 to 68.3 MPa and 63.1 to 63.6 MPa, respectively. The slight increase of AAM compressive strength is caused by high early strength achieved due to the replacement of more than 40 % of fly ash with GGBFS. The presence of more CaO in the AAM mixture accelerates the reaction in early age. By contrast, PC mortar shows significantly strength increases from 55.2 MPa to 69.5 MPa during the same period. Amplitude filters greater than (50dB, 60dB, 70dB and 80 dB) is utilized to investigate the reliability of compressive strength of the mortar by acoustic emission. It was found that filter greater than 60dB is the most suitable filter. Alkali-activated mortars which contain raw material of 42.5% fly ash, 42.5% GGBFS, and 15% micro-silica has the lowest reliability of failure than those of other mortars whereas Portland cement mortar shows the highest reliability of failure than other alkali-activated mortars.

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