Articles

  1. INFLUENCE OF THE STRATIFICATION IN ROCK MASS ON THE STABILITY OF ROADWAYS IN VIETNAMESE COAL MINES Download Article

    Tran Tuan Minh
    • Article Type: Research Article
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    • Pages (1-6)
    • No of Download = 400

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    When the excavation of roadways in the rock mass for underground mining the state of initial stress in the rock mass will be changed, otherwise established the new stress state in rock mass (the secondary stress state after excavation) around openings, respectively. The secondary stress state in rock mass has influence on the design and stability of roadways. Recently the estimation values of stress and deformation around roadways in underground mines when they are excavated in bedding rocks is limited problem. One of many factors concerns to the values and directions of the earth pressure on the steel supports is ratio between span of roadways and thickness of rock mass layers. This paper introduces the assessment of the stress and deformation around roadways and internal forces in the steel supports to determinate suitable locations of the friction joints of steel ribs in the roadways when consideration to change span ratio of roadways and thickness of rock mass layers in bedding rocks in the Quang Ninh underground mines of Viet Nam.

  2. CU AND ZN CONCENTRATIONS OF NATURAL OYSTERS IN OSAKA BAY, JAPAN Download Article

    Tetsuya Fukano and Hiroyuki Ii
    • Article Type: Research Article
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    • Pages (7-15)
    • No of Download = 320

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    Cu and Zn concentrations found in oysters in Osaka Bay were 0.09 to 7.8 ‰ and 1.7 to 37 ‰. Particularly high Cu concentration was found in oysters at fishing ports as well as a yacht harbor and leisure boat wharf. High Zn concentration oysters were also found at fishing ports, yacht harbor, wharf and near food factories. Anti-fouling paint, found in large quantity at the small fishing port, contained Cu2O as a biocide for biofouling and Zn concentrations of anti-fouling paint were also high. This anti-fouling paint was suspected to be the main Cu and Zn contaminant for oysters. Among all oyster parts for natural and cultivated oysters, Cu and Zn concentrations were highest in the oyster gills. Cu and Zn concentrations in the mantle and hepatic gland were almost the same value while adductor muscle values were low. As Cu and Zn concentrations in cultivated oysters were very low, less than 0.1 and 1.1 ‰, natural oysters are considered as effective for getting Zn and Cu in Osaka Bay.

  3. PROBABILISTIC SEISMIC HAZARD ANALYSIS OF SOUTH-WESTERN NIGERIA Download Article

    John Oluwafemi, Olatokunbo Ofuyatan, Solomon Oyebisi, Tolulope Alayande and Masi Tumba
    • Article Type: Research Article
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    • Pages (16-22)
    • No of Download = 302

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    For about ten decades, the seismic record of Nigeria has shown the occurrence of several magnitudes of earthquakes. This is contrary to the belief of some people in time past that Nigeria is aseismic. In number and in size, most of the witnessed earthquakes in Nigeria are found to occur in her South-Western region. Researchers have also begun to warn recently that some regions of Nigeria should prepare for devastating earthquakes in years to come. Hence this paper aimed at the probabilistic seismic hazard analysis of the South-Western region of Nigeria using the available historical and instrumentally recorded data. The Gutenberg-Richter (G-R) recurrence law was used to assess the seismicity parameters and to generate a model for calculating the mean annual rate of exceedance and to forecast probable future earthquake occurrence in the South-West. The findings of this assessment established that the South-West region of Nigeria is likely to experience earthquake magnitude as high as 7.2 in the year 2028 with a probability of 36.79%. Hence, this work enlightens on the extent of probable future earthquake magnitude in South-Western Nigeria and it is recommended that the government of Nigeria and inclined agencies begin to look into earthquake in this region.

  4. CURRENT STATUS OF CONSTRUCTION AND DEMOLITION WASTE MANAGEMENT IN VIETNAM: CHALLENGES AND OPPORTUNITIES Download Article

    Nguyen Van Tuan, Tong Ton Kien, Dang Thi Thanh Huyen, Tran Thi Viet Nga, Nguyen Hoang Giang, Nguyen Tien Dung, Yugo Isobe, Tomonori Ishigaki, and Ken Kawamoto
    • Article Type: Research Article
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    • Pages (23-29)
    • No of Download = 433

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    With rapid urbanization and economic growth on all fronts, much construction is conducted everywhere in Vietnam, especially in big cities such as Hanoi, Haiphong, and Ho Chi Minh. All these activities, new construction, renovation, and demolition of buildings and structures, generate huge amounts of waste, called construction and demolition waste (CDW). According to the State of the Environment report of 2011 on solid waste management issued by Ministry of Natural Resources and Environment, the total municipal solid waste generation was about 60 thousand tons/day on average, of which the CDW waste accounts for 10–12% of total solid waste. In order to maximize the potential positive impacts but at the same time to minimize the negative effects of modernization and industrialization in Vietnam, it is necessary to take immediate measures to protect the environment. This paper describes the current condition of CDW management in Vietnam and presents the challenges and opportunities of CDW recycling. The end solution intended will be to propose suitable CDW management and recycling strategies that suit these conditions with proven benefits for all stakeholders.

  5. CONCENTRATIONS OF METAL(LOID)S IN OUTDOOR AND INDOOR DUST FROM RUSSIAN CITY Download Article

    Tatyana G. Krupnova, Irina V. Mashkova, Svetlana V. Gavrilkina, Evgeniy D. Scalev and Nikita O. Egorov
    • Article Type: Research Article
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    • Pages (30-37)
    • No of Download = 396

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    The metal(loid)s content in the environment is one of the important issues in the environmental management. The metal(loid)s may be present in the both from naturals like natural components of the Earth's crust and anthropogenic sources as human activity effects. Some metal(loid)s are toxic and dangerous for the environment. Chelyabinsk was chosen for researching as a typical industrial Russian city. Road dust and household dust were collected to investigate the contamination of metal(loid)s (Cr, Ni, Cu, Zn, As and Pb) in outdoor and indoor urban. A total of 32 road dust and 17 household dust samples were collected in the urban area during August 2017. The concentrations of metal(loid)s in the dust samples were determined using Аnalyst 400 (Perkin-Elmer) atomic absorption spectrometer with a flame atomization mode. The study shows that Zn has the highest content in road dust whilst in household dust, both As and Ni have the highest content. Cu, Pb, Zn and Cr contamination were significantly elevated in the outdoor and indoor dust.

  6. EFFECTS OF CULVERT SHAPES ON POTENTIAL RISK OF HYDRAULIC FRACTURING ADJACENT TO CULVERTS IN EMBANKMENT DAMS Download Article

    *Duy Quan Tran, Shinichi Nishimura, Masateru Senge and Tatsuro Nishiyama
    • Article Type: Research Article
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    • Pages (38-44)
    • No of Download = 366

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    Hydraulic fracturing is generally considered as one of the most probable causes of dam failures and concentrated leakage occurring adjacent to the outlet conduits in embankment dams. It is thought that hydraulic fracturing will occur in a fill dam when the stress in the dam is reduced to levels that are lower than the water pressure, causing the subsequent propagation of cracks in the dam body. This phenomenon might be closely related to the arching action which occurs around the culverts due to the effects of the culvert configurations. The aim of this study is to investigate the effects of culvert shapes on the potential for hydraulic fracturing close to culverts in fill dams using the finite element method. Many numerical analyses are taken here to determine the stress distributions around culverts with various shapes. The possibility of hydraulic fracturing is then predicted by comparing the values of normal stress and water pressure. The results reveal that there is a probable risk of hydraulic fracturing occurring adjacent to box-shaped culverts in embankments. In addition, box-shaped culverts with inclining chamfers or arc-chamfers on the culvert top also have a similar potential for hydraulic fracturing because the chamfers have a negligible effect on the stress on the sides of the culverts. However, in culverts with slanted walls, that have a gradient for the slanted walls equal to 0.4 or greater, the risk of hydraulic fracturing might be reduced.

  7. BIOSORPTION OF CU (II) BY SCENEDESMUS OBLIQUUS: OPTIMIZATION IN PHOVASOLI HAEMOTOCOCCUS MEDIUM Download Article

    Astri Rinanti, Melati Ferianita Fachrul, Rositayanti Hadisoebroto, Mawar D.S. Silalahi
    • Article Type: Research Article
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    • Pages (45-52)
    • No of Download = 322

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    Biosorption of copper (Cu2+) in electroplating wastewater by biosorbent using Scenedesmus obliquus green algae has been investigated in the artificial medium of Phovasoli Haemotococcus Medium (PHM). The study aims to find an alternative for the treatment of wastewater containing copper (Cu2+) using S.obliquus as a biosorbent, uses a batch test with various pH 4, 5, 6, 7 and 8 as well as the various contact time of 60, 120, 180, 240 and 300 minutes. Some ratios of wastes versus nutrients (Cu2+ : nutrient) in the treatment were A (1: 3), B (1: 1), C (3: 1) and D (100% of waste) with the initial concentration respectively, A (5.05 mg/L), B (16.54 mg/L), C (21.85 mg/L) and D (30.28 mg/L) at 28°C ± 2. The results of the study show that the biosorption rate and the abilities of the sorbent are influenced by pH and contact time (adsorption rate). The maximum uptake rate for Cu2+ was obtained at pH 6 in 240 minutes. In the ratio of waste: nutrient = 1: 3, the uptake rate was 65.54% ± 8.04 while when 100% waste, the uptake rate was 41.99% ± 1.01. The adsorption of copper (Cu2+) is due to the destruction of the cell wall. Analysis of Fourier Transform Infrared (FTIR) shows the adsorption band of functional groups such as carboxyl, amine, and alkene. It indicates the interaction between S.obliquus and the copper ion (Cu2+). The adsorption process of this study follows the Freundlich isotherm equation.

  8. KASHWANI RISK ASSESSMENT: NEW APPROACH FOR OIL AND CONSTRUCTION INDUSTRIES Download Article

    Ghanim Kashwani, Engui Liu, Waleed Nawaz
    • Article Type: Research Article
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    • Pages (53-61)
    • No of Download = 315

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    The aim of this study is to provide an integrated framework that can optimize the implementation of the safety engineering system through the usage of a risk assessment. Current safety studies in oil & gas and construction exposed the presently weak areas in the risk assessment application thereby aiding the selection of the framework inputs in this research. There are three main sections employed as filters during the hazard identification stage in which each one of them has specific criteria. Such a focus will facilitate avoiding the kind generalizations practiced in most risk assessment sessions to cover all the possible scenarios that can occur with the existing hazards. Each group has three standards that should clarify the identified hazard, its dimension and interaction mechanism with the wanted construction activity. Following this full examination, a regular risk assessment procedure is carried out where risk estimation and evaluation will be conducted. At the same time, risk monitoring will be involved in the all steps to facilitate a healthy communication between the parties, especially the management and end-users.

  9. FLOOD CONTROL STRATEGY IN SAMPANG CITY, EAST JAVA, INDONESIA Download Article

    Kustamar, Fourry Handoko and Aryuanto Soetedjo
    • Article Type: Research Article
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    • Pages (62-67)
    • No of Download = 293

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    Flood always hits Sampang City every year and it causes the transportation disruption in Madura Island. The flood in Sampang City is caused by four main factors: the watershed (DAS) quality, the drainage system, the river capacity, and the tide. The flood control strategies that have been done are: the reduction of flood discharge peak and increasing the river capacity. However, these strategies have not achieved the significant results yet. Thus a new strategy is needed to solve the problem. The result of hydrography analysis shows that the discharge is dominated by the surface runoff, thus it indicates that the quality of DAS is very poor. Further, the land usage in DAS is dominated by the agricultural land such as the farms and the rice fields. Based on these observations, a new flood control strategy by controlling the surface runoff on agricultural land is proposed. The strategy is described as the technical activities in the form of utilization of the farmland partition as the temporary storage facilities. To achieve the maximum result, it should be followed by the following activities: a) increasing the capacity of interception and infiltration by the land conservation; b) increasing the capacity of the water reservoir on the land by raising the embankment design from 30 cm to 50 cm; c) shortening the water puddle time by constructing the absorption wells. The result of the hydrological analysis shows that the new strategy is able to reduce the flood discharge peak of 20% to 67%.

  10. IDENTIFICATION OF RESERVOIR THICKNESS OF IJEN (GEOTHERMAL PROSPECT AREA, INDONESIA) USING RESISTIVITY METHOD WITH SCHLUMBERGER CONFIGURATION Download Article

    Akhmad Afandi, I.G.N.B. Catrawedarma, Sukir Maryanto, Ahmad Nadhir, M. B. Zaman and Nugroho Agung Pambudi
    • Article Type: Research Article
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    • Pages (68-75)
    • No of Download = 276

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    This research has been conducted to study geothermal potential in the Ijen area of Banyuwangi - East Java, Indonesia based on the resistivity method with Schlumberger configuration by using a Nanura resistivity meter device, model NRD 22S, and Garmin GPS. This study aims to understand the distribution and the thickness of the reservoir. The results showed that the lithology found in Ijen are tuff, volcanic breccia, lava, sulfur, and a mix of sand and tuff is found with acidic create water. The reservoir is characterized by a low resistivity value of tuff (10.49 Ωm – 89.78 Ωm). The reservoir of Ijen Geothermal area is encountered at point 1 at a depth of 18.04 - 30.44 m with a thickness of 12.4 m and at a depth 63.38 m – 90 m with a thickness 26.62 m, at point 3 at a depth of 73.93 m - 110 m with a thickness of 36.07 m and at point 5 at a depth of 1.91 m - 24.95 m with thickness of 23.04 m and a depth of 32.56 m - 45 m with thickness of 12.44 m. The 3D modeling is done on the resulting lithology, where reservoir which is the main target of this study has a volume of 20.802.000 m3 which is about 42.7% of the total volume of the 3D model.

  11. EFFECT OF SALT COMPOSITION ON THE SEPARATION PROFILE OF CONTAMINATED GROUNDWATER IONS BY ELECTRODIALYSIS Download Article

    Nasrul Arahman
    • Article Type: Research Article
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    • Pages (76-83)
    • No of Download = 264

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    Chloride, nitrate, sulfate, and fluoride ions are sometimes available in groundwater at an elevated level, which is harmful to humans and the environment. The membrane separation technique has been widely explored for controlling the level of those ions in drinking water, particularly the electrodialysis method. In the present study, divalent (AMX) and monovalent ion selective (ACS) anion exchange membranes were used to remove the high concentrations of chloride and other co-existent ions from groundwater samples. The study focuses on the effect of the composition of the salt in the groundwater on the reducing profile of ions, the number of deionized ions, and the rate of ion removal in the diluting compartment. To achieve these experimental objectives, two series of ion samples composed of sodium and calcium were designed. The compositions of the ions were NaCl, Na2NO3, Na2SO4 for the Na-compound, and CaCl2, Ca(NO3)2.4H2O, CaSO4∙2H2O, and CaF2 for the Ca-compound. The electrodialysis experiment was run at a constant applied voltage (8 volts), using sodium nitrate as the electrode solution. In summary, the ED performance for all the investigated parameters was better in the case of ions composed of sodium. Furthermore, a change in the applied current against the electrodialysis operation time was also observed. The results indicated that the current requirement by ED to separate ions composed of calcium needed to be slightly higher than that for ions composed of sodium.

  12. STUDY OF THE CHARACTERISTICS OF DIFFERENT COMPONENTS OF RECYCLED CONSTRUCTION AGGREGATE (RCA): STATISTICAL STUDY IN SYDNEY Download Article

    Farzaneh Tahmoorian, Bijan Samali and John Yeaman
    • Article Type: Research Article
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    • Pages (84-90)
    • No of Download = 250

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    The rapid economic growth of countries has led to the construction of new structures and infrastructures. Construction projects use up large quantities of natural resources and produce tones of construction and demolition waste (CDW). Because of its growth, these quantities have increased in the last few years and it has now become necessary to create a sustainable method of development in civil construction. Therefore, utilization of recycled materials in construction projects can be the most promising solution to this problem. The utilization of recycled materials including recycled construction aggregates (RCA) in the pavement industry and asphalt production is particularly very promising as 90% of asphalt is made of aggregates. However, the variability in behavior and performance of RCA used in construction projects indicates the variability in their composition. Therefore, in spite of the awareness of the importance of using RCA and much research being conducted, there is still a need for a deeper study of the composition of the RCA. This paper presents the results of the statistical study and experimental work to evaluate the characteristics of RCA as an alternative for virgin aggregate in the asphalt mixture. To this point, a series of characterization tests were conducted RCA samples collected at different dates.

  13. MODELLING ROAD ACCIDENT FATALITIES IN THAILAND AND OTHER ASIAN COUNTRIES Download Article

    Pongrid Klungboonkrong, Natthapoj Faiboun and Jeremy Woolley
    • Article Type: Research Article
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    • Pages (91-98)
    • No of Download = 425

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    Modelling was conducted of road accident fatalities (RAFs) in Thailand and other Asian countries. Based on a cross-sectional analysis in 2013, an Asian model of predicted RAFs (per population) as a function of motorization (registered vehicles per capita) was developed. In addition, an Asian RAFs (per vehicles) prediction model was also developed. Increasing motorization corresponded with lower estimated RAFs per 10,000 vehicles. Also, the Thailand RAFs (per population) prediction model was achieved based on the limited time series analysis utilizing the 3 RAFs database sources. The motorization could potentially be adapted to estimate the RAFs per 100,000 population in Thailand. Based on the Thailand RAFs prediction model and the predicted motorization in 2020, the estimated RAFs per 100,000 population will be 3 times greater than the targeted one. This means that Thailand will not be able to achieve the United Nations Sustainable Development Goal (SDG) for global road safety issues.

  14. MODEL HABITAT QUALITY IN THE FUTURE IN PADANG CITY Download Article

    Yudi Antomi, Dedi Hermon, Erianjoni, Dasman Lanin, Indang Dewata and Abdul Razak
    • Article Type: Research Article
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    • Pages (99-107)
    • No of Download = 226

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    The loss of environmental services to humans results from a continuous change in land use. The purpose of this study is to predict the condition of current and future environmental services through the calculation of habitat quality based on the trend of land use change in Padang City. This research begins with an interpretation of Landsat's temporal image, field surveys, focus group discussions, and an analysis of the impacts of land-use change. To collect land use data is done by image interpretation. A field survey was also conducted to determine the impact of land use change and its solutions. In carrying out this model used the quality and rarity habitat tool released by the Natural Capital Project under the name of the Integrated Valuation Ecosystem Services and Tradeoff (InVEST) parent modeler. The results of this study show the condition of environmental services in the city of Padang at the time of the research conducted in 2017 in the aspect of habitat quality showed significant decline until 2030, the intervention of spatial pattern (RTRW) Padang city able to provide an increase in the area of excellent quality from 51.36% to 52.27%, so the role of RTRW is very significant in maintaining and improving the quality of habitat in Padang City.

  15. THEORETICAL AND EXPERIMENTAL VALIDATION OF SEISMOELECTRICAL METHOD Download Article

    Georgy Ya. Shaidurov, Vadim S. Potylitsyn, Danil S. Kudinov, Ekaterina A. Kokhonkova and P.V. Balandin
    • Article Type: Research Article
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    • Pages (108-113)
    • No of Download = 238

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    The main aim of this study is a theoretical and experimental validation of the method based on a recording of the seismoelectrical effect upon excitation of seismic fields by the special non-explosive striker and without an additional source of the electromagnetic field. Signals of seismic and electrical fields were recorded using earthed electric dipoles and seismic receiver with subsequent processing using seismic acquisition system. The frequencies of recorded fields were in the range of 0.1–20 Hz. The observation results of seismoelectrical effect resulted from excitation of the geological section by seismic shocks (a KEM-4 striker) and recording of secondary electrical and seismic fields on the surface by measurements of their cross-correlation function. The activities were performed during July 23–30, 2017 on Bystryansky gas condensate field (Krasnoyarsk Krai, Minusinsk district). The productive deposit was indicated by the maximum coefficient of cross-correlation by three times higher than normal background. 3D maps of the seismoelectrical section were obtained for the first time.

  16. A STUDY ON CLAY SOIL IMPROVEMENT WITH BACILLUS SUBTILIS BACTERIA AS THE ROAD SUBBASE LAYER Download Article

    Hasriana, Lawalenna Samang, M. Natsir Djide and Tri Harianto
    • Article Type: Research Article
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    • Pages (114-120)
    • No of Download = 275

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    This study aims to investigate the bearing capacity of the high-plasticity clay soil with bacteria stabilization (Bacillus subtilis). The growth of bacteria with the phase of 6 days was used as a stabilizing agent. The assessment of bearing capacity was based on unconfined compressive strength value, California Bearing Ratio (CBR), and modulus of soil reaction as a subbase layer. The test results show that the compressive strength value tends to increase with the addition of 2% to 6% bacteria and decrease with 8% bacteria. This phenomenon corresponds to the increase of CaO value due to Microbial-Induced Calcite Precipitation (MICP) microstructurally. The compressive strength value curve pattern increases proportionally with curing time of 3, 7, 14, and 28 days. According to the California Bearing Ratio (CBR) value range criteria (20% ≤CBR˂40%) for subbase layer, the use of 3.5 to 6% bacteria can technically be functionally justified as a road material with the modulus of stabilized clay soil reaction value of 68 to 110 kN/m2/mm. The results of this study have technical implications for the significance of the use of Bacillus subtilis bacteria as the biotechnology stabilization material to increase the bearing capacity and modulus of soil reaction with high plasticity clay.

  17. OPTIMIZATION MODELS OF PIONEER ROUTES IN PAPUA PROVINCE Download Article

    Yoniman Ronting, Sakti Adji Adisasmita, Sumarni Hamid Aly and Muralia Hustim
    • Article Type: Research Article
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    • Pages (121-128)
    • No of Download = 269

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    The province of Papua has a very varied topography, ranging from swampy lowlands, hills, and plateaus up steep hills. The total area of land is 319,036,05 km², which consists of 28 counties and one city, 524 districts, and 5,225 villages. The population of Papua Province in 2017 was 3,911,726 with an average growth of 1.95% per year. The transportation services are still minimal, especially in the mountainous region, which is isolated and could only be reached by an air transportation mode. The purposes of this study are to determine (1) the characteristics of pioneering air transport infrastructure and services in the current province of Papua, (2) the cost of transportation of basic needs and price disparities in the Central Highlands of Papua, (3) the acceleration of development of connectivity system in the region The Central Highlands of Papua, and (4) the model of the optimization of pioneer aviation routes and routes in the Central Highlands of Papua. The research is non-experimental and qualitative and quantitative descriptive, which is a case study with survey and direct observation in the field that gives an idea of the object being studied and its development in the future. The optimization analysis tools Solver uses in Microsoft Excel and LINGO 17. The results of the research indicate that the high prices that occur in the central mountains of Papua are not only caused by the high cost of transportation but too much profit taken by traders with an average gross profit margin of 130-366%. The results of route optimization analysis using Solver on Microsoft Excel and LINGO 17 can save transportation cost by 15.85%.

  18. THE RESPONSE OF PILES UNDER TENSION LOADS BASED ON ANALYTICAL METHOD AND FINITE ELEMENT ANALYSIS Download Article

    Kelvin Lo, Dominic Ong and Erwin Oh
    • Article Type: Research Article
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    • Pages (129-136)
    • No of Download = 409

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    In the past, there were many research studies carried out on the response of single piles and pile groups under compression loads, but it was comparatively lesser for piles and pile groups under uplift loads. Uplift loads on piles usually occur in pile foundations supporting wind farm structures, tall chimneys, transmission towers and jetty structures. During recent decades, research studies on piles under uplift loads have progressed, and were mainly focused on the capacity, failure modes and load displacement performance of single piles, but no research has been done on the influence zone of a pile and its effects within a group. This paper presents the initial findings of research to investigate the stress distribution and influence zone of a single pile under uplift loads using a hybrid approach combining analytical theory and 2D Finite Element (FE) analysis. Finally, the effect of the estimated influence zone was successfully verified in 3D FE analysis which confirmed that group efficiency reduced when an adjacent pile was within the estimated influence zone and thus piles behave as a group.

  19. ASSESSMENT OF WAVE ENERGY RESOURCES IN THE VICINITY OF NATUNA ISLANDS Download Article

    Krisnaldi Idris and Desmira Anindya Gammaranti
    • Article Type: Research Article
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    • Pages (137-145)
    • No of Download = 275

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    The objective of this work is to study the wave energy resources and selection of conversion technologies options in the vicinity of the Natuna Islands. This study involves analyzing the wave characteristics of the area and the theoretical wave energy resources currently available and estimating the electricity production of three types of wave energy converters (attenuator, terminator, and point absorber). The 59-year wave data were obtained from the SEAMOS-South Fine Grid Hindcast (SEAFINE) and statistical analysis was performed to obtain probability of occurence of the wave height and wave period, which describe the sea states. The seasonal variations of the wave characteristics were identified. The wave statistical analysis and estimation of energy production were analyzed on a monthly basis. The performance characteristics are provided for selected wave energy converter types, where the performance is a function of the sea state conditions. The incorporation of the probability of occurrence of sea states and performance of the wave energy converter show the highest estimation of electricity production occur during North East Monsoon season, and the lowest one during South West Monsoon season.

  20. ON EXPERIMENTAL OBSERVATIONS OF SEISMOELECTRIC EFFECT AT GAS CONDENSATE DEPOSIT IN EARTH'S ELECTROMAGNETIC AND SEISMIC NOISES Download Article

    G. Ya. Shaidurov, V. S. Potylitsyn, D. S. Kudinov and O. A. Maikov
    • Article Type: Research Article
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    • Pages (146-151)
    • No of Download = 375

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    The main aim of this work is physical interpretation and experimental verification of the method based on a recording of seismoelectric effect in natural Earth's seismic and electromagnetic fields. In this case, a deposit is described by a model of the flat condenser in which ion-conducting medium (deposit waters) serve as plates and deposited hydrocarbons serve as a dielectric layer. The considered frequencies of both types of fields are in the range of 0.1–20 Hz. The calculated curve of electric field distribution on Earth's surface generated by deposit seam induced by natural electric and seismic fields of the Earth’s crust is given. Experimental data of observations of seismoelectric effect in passive fields are presented obtained in 2014–2017 at Bystryansky gas condensate field (Krasnoyarsk Krai, Minusinsk district) by the recording of passive electric and seismic fields as well as measurement of their cross-correlation.

  21. VISCOSITY EFFECT ON SOIL SETTLEMENTS AND PILE SKIN FRICTION DISTRIBUTION DURING PRIMARY CONSOLIDATION Download Article

    Salma Al Kodsi, Kazuhiro Oda and Talal Awwad
    • Article Type: Research Article
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    • Pages (152-159)
    • No of Download = 418

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    Skin friction distribution occurs due to a relative movement between pile and adjacent soil. Varied factors affecting this movement get the soil to, occasionally, settle more than that of the pile. In this case, negative skin friction distributes along some part of the pile's shaft. Primary consolidation begins after applying surcharge load on ground surface next to pile’s head - where pressure will be carried by the pore water until the entire excess pore pressure dissipates and shear stress is mobilized. This paper presents a finite element parametric study to investigate the effect of viscosity on soil settlements and skin friction distribution along the pile during primary consolidation. Single pile in clay soil is modelled using FORTRAN in conjunction with two different soil constitutive models. On the one hand, numerical modeling has been carried out using the elasto-plastic soil behavior – as defined by Matsui-Abe soil constitutive model. On the other hand, the effect of viscosity has been modeled using the elasto-viscoplastic soil model as defined by Sekiguchi-Ohta model. A parametric study has been conducted in order to compare the results of the above two soil models to clarify the viscous impact. FORTRAN 2-D analytical model has been validated by comparing numerical results with two field tests measurements. Viscosity is clearly effective when a specific value of surcharge load is applied. Structural viscosity has increased the soil settlements compared to the other settlements that occurred by using elasto-plastic soil model – where part of the pile induced by negative skin friction becomes greater.

  22. THE CORRELATION OF EXPOSURE TIME AND CLAYSTONE PROPERTIES AT THE WARUKIN FORMATION INDONESIA Download Article

    Supandi, Zufialdi Zakaria, Emi Sukiyah and Adjat Sudradjat
    • Article Type: Research Article
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    • Pages (160-167)
    • No of Download = 294

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    The deterioration of claystone material was studied by observing a mine slope after digging. An understanding of the degradation of material properties based on field characteristics was required for a detailed slope stability analysis. Experiments were carried out to investigate the correlation of exposure time and the degradation of the mechanical properties of claystone. The methods used in this research include direct field observation and measurements taken from samples of claystone. Claystone samples with different exposure times were obtained from the mine slope face. The exposure time was calculated from the time the slope was dug (when mining started). Determination of the mechanical properties was conducted using undrained, unconsolidated triaxial testing and uniaxial testing. Statistical analysis was carried out to determine the mineralogical homogeneity of the claystone. An empirical analysis was carried out by plotting the exposure time against the mechanical properties on a scatter diagram. The degree of correlation was one parameter used to determine the relationship between the exposure time and material behavior. Based on the results of the research, it is known that the time span of exposure correlates strongly with material properties due to weathering and degradation. The decline in strength was accelerated after the material is exposed. Strength gradually decreased to moderate after 200 days of exposure. Furthermore, the mechanical properties of claystone material will be stabilizing after 400 days. The results of the analysis were very important in predicting the behavior of claystone with exposure time on a slope.

  23. BLAST RESISTANT DESIGN PARAMETERS AGAINST AN UNCONTROLLED DEMOLITION (IMPLOSION) IN AUSTRALIA Download Article

    Graeme McKenzie, Bijan Samali, Chunwei Zhang and Eric Ancich
    • Article Type: Research Article
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    • Pages (168-176)
    • No of Download = 225

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    Because of the uncertainty that presently exists within the Australian community of a possible improvised explosive device (IED) or vehicle improvised explosive device (VIED) detonating at some time in the not too distant future there is uncertainty as to what would happen if an Australian engineer was approached by a civilian developer to either design a new commercial structure or design a retrofit an existing commercial structure what explosive charge weights are to be designed for and what type of explosives will be used? With no Australian Standard or Design Code yet available the engineer could look for overseas examples for design parameters. Three events were considered in this paper using CONWEP software. A 5kg IED detonated on a top deck of a London bus with zero detonation distance amongst travelers generating a peak pressure of 32.69MPa, a 1020kg VIED was detonated 3m from a club generating a peak pressure of 10.29MPa and a massive 2990kg VIED was detonated 6m from a multi-storey RC building generating a peak pressure of 5.83 MPa. Peak pressures in all three events meant all were well above lethality for people and that destruction of assets they were detonated in or next to was inevitable. As explosive charge weights can’t be controlled the only parameter a designer can dictate is range. So, any design must be such that it forces a terrorist to detonate as far away from the intended target as possible thus reducing blast overpressures that impact people or assets.

  24. HYDROCHLORIC ACID HEAT REACTION METHOD TO MEASURE CEMENT CONTENTS IN CEMENT MIXED SOILS Download Article

    Hiroshi Kubo, Shinya Inazumi and Toshihiko Miura
    • Article Type: Research Article
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    • Pages (177-183)
    • No of Download = 409

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    The mixing cement with soft soil to increase their strength has been used in many construction sites and it is important that soil and cement are well mixed. In order to evaluate the mixing accuracy during construction, it may be required to measure the cement content by sampling the cement mixed soil. While there are several methods for measuring cement content, the hydrochloric acid heat reaction (HAHR) method is easiest and quickest and is relatively high in precision to measure the cement content in fresh concrete. However, to apply HAHR to the fresh soil cement, there were many questions about a test condition. This study investigated conditions to apply the HAHR method to cement mixed soil. At first, cement are mixed to the local soil samples in the ratio of 0 to 10g/100g. Initial temperatures (T0) of the mixed soil and hydrochloric acid are measured. 100 g of mixed soil is put in an insulated container. 100mL of hydrochloric acid is added, and reaction temperature (T1) is measured. Relationship of temperature rise (T1-T0) and cement content is a calibration graph. The relation is proportional. And, the temperature rises are measured about 100g of cement mixed soil of the site. Its cement content is obtained using the calibration curve. It is optimal to use 6M hydrochloric acid for this method. It is necessary to examine it with local soil and local cement to prepare a calibration curve. When the water content ratio of the soil greatly changes, it is necessary for the calibration curve to be updated. HAHR tests are done in 10 to 60 minutes after having mixed soil and cement in the case of samples containing a little water. But, in the case of containing much water, the tests are done under the specified elapsed time. As an example of the result, the cement content of soil can be determined from the rising temperature of the sample soil.

  25. DISCRETE CONFINEMENT BY METAL SHEET STRIPS ON CONCRETE COLUMNS UNDER AXIAL COMPRESSION Download Article

    Apichai Positong, Tanyada Pannachet and Maetee Boonpichetvong
    • Article Type: Research Article
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    • Pages (184-191)
    • No of Download = 375

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    The environmental load factor in the ISO 19902 standards is derived based on conditions in the Gulf of Mexico, which are more extreme than conditions in Indonesia. This study is a preliminary investigation of the environmental load factors appropriate for the Java Sea, as this is a region in Indonesia where many platform structures are already in operation. Evaluation of an environmental load factor for Indonesia is carried out by performing reliability analyses using Monte Carlo simulations, in which the failure performance is determined by the first yield stress condition in the critical member of two fixed platform structures. From the results, an appropriate environmental load factor of 1.16 is proposed for the Java Sea, which is smaller than the value given in the ISO 20002 Standard for the Gulf of Mexico. More comprehensive environmental load factor research for other Indonesian regions should be done to complement this result.

  26. GEOCHEMICAL STUDY OF THE TIGRIS RIVER SEDIMENTS IN THE SURROUNDING AREA OF BAGHDAD MEDICAL CITY Download Article

    Amani Loay Mohammed Salih, Shahad Adil Al-Qaraghul and Rami Mahmood Idan
    • Article Type: Research Article
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    • Pages (192-198)
    • No of Download = 366

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    Heavy metals contamination of water and soil represents a major environmental threat that is to be monitored on a regular schedule in order to avoid its negative consequences. This study is dedicated to evaluating the water and the soil state in the perimeter of Baghdad Medical City`s complex that is located adjacent to the great Tigris River. Water and soil samples were collected from three stations on both sides and middle of the river; upstream, downstream and at the complex`s wastewater discharge point to the river. Chemical and atomic absorption spectrophotometer tests have shown that the concentrations of Cd, Pb, and Ni in water and soil are within the permissible WHO limits for all upstream samples, but they increase significantly beyond the complex`s wastewater discharge location. Also, Chemical indicators have shown a similar trend for all tested samples in a clear announcement for the possible direct threat to the surrounding environment and residents/benefits, with its main spot at the medical complex, in order to initiate sudden remediation acts.

  27. GEOCHEMICAL AND PETROPHYSICAL ASSESSMENT OF TELISA SHALE GAS RESERVOIR: A CASE STUDY FROM SOUTH SUMATRA BASIN, INDONESIA Download Article

    Abdul Haris, Aldo Hutagalung and Agus Riyanto
    • Article Type: Research Article
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    • Pages (199-205)
    • No of Download = 374

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    The geochemical and petrophysical assessment of a shale gas reservoir in Telisa Formation in South Sumatra Basin was carried out to identify the gas potential distribution. The assessment was performed based on geochemical and petrophysical data, which were integrated with and seismic attributes to spatially distribute the organic richness of the shale gas reservoir. The objectives of this paper are to characterize core samples in terms of the total organic carbon (TOC), kerogen type and thermal maturity of shale gas layers that were derived from the well log data. In addition, seismic attribute analysis such as acoustic impedance, which is associated with TOC, was explored to spatially distribute the shale gas potential. The assessment results showed that the organic richness of the Telisa shale gas reservoir is classified into fair quality with TOC in the range of 0.75-1 weight (wt) %. The kerogen type of the Telisa shale gas reservoir is considered as a mixture of type II/III (oil/gas prone) to type III (gas prone). In terms of vitrinite reflectance, the Telisa shale reservoir is categorized as in a mature stage, representing an oil window up to a wet gas window. The prospective reservoir distribution is indicated by a shale lithology characterized by a high acoustic impedance range of 20000-24000 ((m/s). (g/cc)).

  28. RAINFALL TREND BY LINEAR REGRESSION ANALYSIS OVER INDOCHINA PENINSULA DURING 1981-2017 (37 YEARS) Download Article

    Usa Humphries, Pramet Kaewmesri and Pariwate Varnakovida
    • Article Type: Research Article
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    • Pages (206-213)
    • No of Download = 349

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    The objective of this study used data from the Global Rainfall Climatology Project (GPCP) global gridded data observation to statistical analysis rainfall over the Indochina Peninsula (from 1981 to 2017 (37 years)) with a domain of 2.5° by 2.5° grid spacing. The central tendency (mean, range, etc.) and dispersion (S.D, CV, etc.) were used in the statistical analysis. For identifying the trend in the rainfall data, the statistical analysis of linear regression was used in this study. The results in this study were shown the total amount of rainfall changes over three periods that were period I (1981-1990), period II (1991-2000), period III (2001-2010) and period IV (2011-2017). In the basic statistical was analyzed rainfall annual, rainfall monthly, and regression monthly rainfall analysis over ICP. In basic statistical was shown the highest annual mean rainfall was 2017, which recorded an amount of 162.91 mm. The record indicated the standard deviation correlating the highest annual mean rainfall was 51.99 mm. From the results of the linear regression analysis revealed downward trends in the rainfall for the months of April, July, October, and December and an upward trend for other months. In this study was shown the overall trend of the spatial pattern over ICP.

  29. ANALYSIS OF CO EMISSION OF HETEROGENEOUS TRAFFIC USING CALINE 4 AT DAYA PASSENGER TERMINAL IN MAKASSAR INDONESIA Download Article

    Sumarni Hamid Aly
    • Article Type: Research Article
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    • Pages (214-221)
    • No of Download = 260

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    Motor vehicles have been a primary source of CO emissions in many major cities in the world, including in Makassar, Indonesia. The increasing of the motor vehicle under heterogeneous traffic condition on the Daya Passenger Terminal (DPT) leads to the air pollution rise that emitted by the vehicles as consequently. This study aims to predict the quantity and model of CO emissions distribution using the Caline 4 in DPT. In 2016, vehicle volume and CO emission data collection were conducted on 10 receptors in DPT and meteorological data obtained from Indonesia Agency in the Makassar region. The results are the emissions tend to be the same in 2016 and 2017 with the largest amount of CO emissions in receptor 9 and compared to 2018 decrease by 33%. The CO emission distribution model is highly influenced by wind speed and dominant direction and has different models, which are 5, 3, 4 in 2016, 2017, and 2018 respectively. For further research, this study is particularly useful as preliminary information related to air quality mitigation.

  30. FATIGUE AND AGGREGATE FRETTING RESISTANCE OF SURFACE-TEMPERATURE REDUCING PAVEMENT Download Article

    Hiroshi Higashiyama, Hiromu Inoue and Manote Sappakittipakorn
    • Article Type: Research Article
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    • Pages (222-229)
    • No of Download = 415

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    In the field of road engineering, cool pavements are used to decrease the surface temperature and improve the road environment. A surface-temperature reducing pavement was previously developed using a cement-based grouting material containing cement, ceramic waste powder, and natural zeolite. From the temperature measurements, it was revealed that the surface temperature was lower by 15-20°C than the porous asphalt pavement at 60°C. The pavements can undergo rutting under passing traffic loads and aggregate fretting in the hot summer season, lowering serviceability and traffic safety. Fatigue tests under a fixed-point load were conducted to evaluate the fatigue resistance of the surface-temperature reducing pavement at 40°C imitating the hot summer season. In this study, fatigue tests under a fixed-point load at 30°C imitating the spring or autumn season were carried out to evaluate the fatigue resistance against the rutting. Furthermore, the aggregate fretting tests were carried out to evaluate the aggregate fretting resistance at temperatures of 50°C and 30°C. The test results showed that the surface-temperature reducing pavement has higher fatigue and aggregate fretting resistance than the porous asphalt pavement.

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