Articles

  1. SEISMIC RISK EVALUATION OF IRRIGATION TANKS: A CASE STUDY IN IBIGAWA-CHO, GIFU PREFECTURE, JAPAN Download Article

    Chen Fang, Hideyoshi Shimizu, Shin-Ichi Nishimura, Ken Hiramatsu and Takeo Onishi
    • Article Type: Research Article
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    • Pages (1-6)
    • No of Download = 285

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    Landslides are one of earth’s most serious types of natural disasters and they are often induced by earthquakes. Predicting the approximate landslide displacements caused by earthquakes is helpful for assessing earthquake hazards and for designing slopes to withstand future seismic shaking. In this research, the authors firstly focus on obtaining the residual strength parameters and the peak strength parameters by multistage procedure with the Bromhead ring shear apparatus, which are used in the slope stability analysis. The maximum vertical settlement (MVS) of a slope is determined by the Newmark method using representative data from three earthquakes, i.e., Great Hanshin Earthquake, Chuetsu Earthquake and Iwate-Miyagi Nairiku Earthquake. It is experimentally demonstrated that the MVS is very large in both Tanigumi Pond and Sugo Pond. Once a great earthquake occurs, the progressive failure phenomenon appears and people living in the area will be in danger. The results presented in this paper can be applied to future landslide hazard assessments and used to promote reconstruction efforts by the government in the affected areas and for future disaster prevention and mitigation.

  2. ENHANCEMENT OF MICROBIALLY INDUCED CARBONATE PRECIPITATION USING ORGANIC BIOPOLYMER Download Article

    Thiloththama Hiranya Kumari Nawarathna, Kazunori Nakashima and Satoru Kawasaki
    • Article Type: Research Article
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    • Pages (7-12)
    • No of Download = 227

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    Microbially induced carbonate precipitation (MICP) by using ureolytic bacteria is a novel and environmentally friendly way to treat the un-cemented sand. It was implemented successfully in number of geotechnical applications. Use of organic additives to improve the MICP process is a novel and interesting approach. In this research, effect of the cationic biopolymer poly-l-lysine on the MICP process was investigated by using ureolytic bacteria Pararhodobacter sp. Urea hydrolysis by the bacteria in the presence of CaCl2 was conducted with the addition of the polymer under different conditions. Morphology of the precipitate of CaCO3 after oven dried was analyzed by using the scanning electron microscope. Bell-shaped curve was obtained for the variation between the amount of the precipitate with the increase of the amount of the poly-l-lysine. Poly-L-lysine gives higher amount of precipitate than conventional MICP process and morphology of the crystals changed drastically from well-developed rhombohedral crystals to ellipsoidal shaped aggregates.

  3. FUEL TANK FOUNDATION IMPROVEMENT SYSTEM ON SOFT SOIL LAYER BASED ON 3D NUMERICAL SIMULATION Download Article

    Adhitya Yoga Purnama, Ahmad Rifa’i and Hary Christady Hardiyatmo
    • Article Type: Research Article
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    • Pages (13-18)
    • No of Download = 262

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    Differential settlement on the fuel tank storage foundation in Banjarmasin fuel depot, Indonesia, cause the tilting of fuel tank storage. Due to this condition, the volume measurement of fuel in the tank becomes inaccurate and difficult to be predicted. This problem affects the fuel distribution in Banjarmasin area if not immediately solved. The structure of tank foundation was built on the soft soil without another support structure. This research carried out the study on improvement of foundation structure system with concrete slab supported by piles on the outside around and “Sistem Cakar Ayam” that spread evenly in the area of the foundation. The numerical study of the proposed improvement of structure model was conducted using SAP2000 and ABAQUS. The vertical and horizontal spring elements were chosen as the support system on the foundation model in SAP2000. In ABAQUS, the model defined as a three-dimensional model. The soils idealized by elasto-plastic Mohr-Coulomb model. The slab, piles, and “Sistem Cakar Ayam” defined as elastic material. Based on the numerical analysis results, the analysis using SAP2000 are used to determine the optimum configuration of the pile and there is no excessive differential settlement. A three-dimensional numerical analysis using ABAQUS can represent actual field conditions because the boundary conditions in two-dimensional analysis can be reduced. Reduction of deformations using the proposed system is 70.79%. The proposed foundation system using slab supported by piles and “Sistem Cakar Ayam” are quite effective in reducing the differential settlement due to fuel tank load.

  4. STABILITY CHARTS FOR UNSUPPORTED PLANE STRAIN TUNNEL HEADINGS IN HOMOGENEOUS UNDRAINED CLAY Download Article

    Jim Shiau, Mathew Sams, Fadhil Al-Asadi and Mohammad Mirza Hassan
    • Article Type: Review Article
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    • Pages (19-26)
    • No of Download = 251

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    This paper investigates the stability of plane strain tunnel headings in undrained soils. Using the factor of safety approach via the strength reduction technique, the idealised tunnel heading models are studied using the finite difference program FLAC. This problem is also similar to underground long wall excavations in plane strain condition. The finite difference results are presented alongside upper and lower bound limit solutions for validation. A thorough comparison between these two methods finds a very good agreement. Design charts are presented for a wide range of practical scenarios using dimensionless ratios, similar to Taylor’s design charts used for slope stability. Typical examples are presented to illustrate the usefulness for practising engineers.

  5. JACK-ASSISTED LEVELING PROCESS OF AN ACTUAL 17-STORY BUILDING Download Article

    Juan F. Correal, Juan C. Reyes, Juan S. Echeverry, Andres C. Riaño, Armando Palomino, Álvaro Peláez and Gustavo Gastelbondo
    • Article Type: Research Article
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    • Pages (27-34)
    • No of Download = 253

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    Foundation problems during building construction may cause important structural and nonstructural damage, and compromise the building serviceability. This paper presents a case study of a jack-assisted leveling process implemented on a 17-story reinforced concrete building that suffered important differential settlements during its construction. It is the first time a leveling solution for just a group of piles is implemented, since previous studies considered intervening all foundation piles. The procedure consists on cutting a small slice of the piles in the unsettled side of the building, equivalent to the necessary descent for leveling the settlements in the opposite end, and lowering the unsettled part by a controlled maneuver with hydraulic jacks. Prior to its execution, a numerical model was developed for predicting the effectiveness of the descent maneuver indicating that the leveling process would correct the tilt of the building. The solution was successfully implemented and the building is now in service.

  6. STATE OF THE ART, RECONSTRUCTION OF DAMAGED ZONES: TRANSITORY STRESSES EFFECT AND FACTORS CONTROLLING ROCK MASS STABILITY Download Article

    A. K. Alzo’ubi
    • Article Type: Research Article
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    • Pages (35-43)
    • No of Download = 256

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    For the last three decades, many countries in the Middle East have been bombarded by wars. In these damaged zones, removing of destruction debris and the effect of the direct impact of blasts might trigger rock mass instabilities. This paper discusses the influence of explosives on factors controlling stability of rock masses and shows the available methods to back-analyze, investigate, and/or design near-surface rocks. Explosion waves and the resulted debris may jeopardize the geomaterial stability through different factors such as; introducing new fractures inside rocks and/or soils, temporary increasing water pressure, and dynamic loading-unloading cycles. Upon unloading as a result of removing destruction debris, the stress changes and consequently destabilize soil/rock masses. These effects become of great concern in many civil engineering projects such as, road cuts, foundations, and retaining walls. Rock slopes susceptible to instability could be divided into two categories; the structurally controlled slopes, and the complex rock slopes. One mechanism, to form a continuous rupture surface in complex slopes, is by introducing new fractures through explosions and/or high rate of loading and/or unloading as transitory stresses. The modes of instabilities that have been documented are summarized to introduce the factors affecting the geomaterial slope movement in damaged zones. Hybrid modeling approaches might be the best choice to examine a rock mass vulnerability to movement by simulating the explosive stresses. Modeling the entire reconstruction process and the effect of explosions would help to reduce or to eliminate risks in the construction of new structures in after war region.

  7. PROPERTIES OF COATED AND UNCOATED BIOMASS AGGREGATES AND THEIR EFFECTS ON THE STRENGTH AND WATER PERMEABILITY OF PERVIOUS GEOPOLYMER CONCRETE Download Article

    S.A. Arafa, A.Z.B. Mohd Ali, A.S.M. Abdul Awal, Shamrul-Mar Shamsuddin and M. Zakaria Hossain
    • Article Type: Research Article
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    • Pages (44-51)
    • No of Download = 272

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    Biomass aggregate (BA) is a by-product of biomass industries which is less dense and more porous than natural aggregate. In this two-part study, BA was mixed with fly ash and alkaline liquid, and heated in an oven at 80 °C for 24 h to produce coated biomass aggregate (CBA). The first part of this study was focused on the density, specific gravity, Los Angeles test, water absorption, aggregate impact value, and aggregate crushing value of BA, CBA, and normal aggregates (NA). The second part was focused on compressive strength and water permeability of pervious geopolymer concrete (PGC) that was produced with BA and CBA. Pervious concrete is a non-slip porous pavement concrete that allows water to slip through. In this study PGC was prepared from alkaline solution: fly ash ratio of 0:5, fly ash/coarse aggregate ratio of 1:7, Na2SiO3/NaOH ratio of 2:5, and NaOH concentration of 10 molarity. PGC was cured at 80°C for 24 h. PGC made with CBA had higher compressive strength without much effect on water permeability. It has been found that PGC made with BA and CBA had lower density than PGC made with NA. Results indicated that both BA and CBA are viable alternative aggregates for producing PGC.

  8. IMPLICATIONS OF LAND SUBSIDENCE DUE TO GROUNDWATER OVER-PUMPING: MONITORING METHODOLOGY USING GRACE DATA Download Article

    Mohamed Saber, Mohammed Abdel-Fattah, Sameh A. Kantoush and Tetsuya Sumi
    • Article Type: Research Article
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    • Pages (52-59)
    • No of Download = 305

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    Groundwater over-pumping is a chief contributor to groundwater quality degradation and land subsidence. Expecting land subsidence is quite difficult, thus using satellite data to monitor such disaster is highly promising. This paper presents the use of Gravity Recovery and Climate Experiment data along with Global Land Data Assimilation System data to monitor and investigate land subsidence resulting from the impact of groundwater depletion in different regions throughout the world. The trend rates of groundwater depletion were spatiotemporally estimated to map and detect the occurring and prone regions of land subsidence. The groundwater storage changes exhibit a declining linear trend during the testing period (2002-2015) with a rate of 3.4 km3/year at Missouri State in US. Based on the estimated linear tend of groundwater depletions, the method is validated at Missouri State by some exiting land subsidence such as sinkholes. Then, the approach is applied for the global and continental scales as example of US. The results also exhibit that the southern and some in the northern of US are the most prone regions for land subsidence. During the period 2009-2013, there was a great depletions and the results exhibit that mostly the abstractions from the North to the south of US and especially in the middle. Global estimates of groundwater storage changes also were conducted which can be used to estimate the groundwater depletion trends at any region throughout the world. These analyses could be helpful for monitoring and assessment of land subsidence in regions where subsidence impacts are great.

  9. THE EFFECT OF GRAVITY MEASUREMENT DISTRIBUTION POINTS ON INTERPRETATION OF GRAVITY DATA IN THE GUNUNG ENDUT GEOTHERMAL PROSPECT AREA, INDONESIA Download Article

    Supriyanto, Rokhmatuloh, Robi Sobirin and Edi Suhanto
    • Article Type: Research Article
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    • Pages (60-67)
    • No of Download = 467

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    The geothermal prospect located at Gunung Endut was investigated in 1980s based on reconnaissance surveys, primarily on geological and geochemical aspects. Then in 2006 a gravity measurement with 247 stations was carried out. However, due to the distribution of the gravity station was less than optimal, interpretation of gravity data was not suitable with the geological situation that support geothermal system. To ensure this, we have carried out a new gravity survey with 134 random stations distribution but remained concentrated on hot spring locations. Data from both measurements were processed by the same treatment starting from pre-processing with some standar corrections to obtain complete Bouguer anomaly, then continue by filtering process to separate regional and residual gravity anomaly using Butterworth filter in a wavenumber domain. Residual gravity anomaly map obtained by random position of stations is more resemble to the geological features developed in the prospect area. The contrast boundaries of the residual gravity anomaly value coincide with the fault-line structures recorded in the surface geological data. This result is better when compared with previous measurements. This study shows that there is a significant influence of the distribution pattern of the gravity stations which affects the conformity with the geological data. Based on the new interpretation result, the structural features in the prospect area are characterized by the complex fault structures that intersected each other mainly close to the surface manifestations. This intersection area is expected to be an enhanced permeability zone so that the hydrothermal fluid can flow to the surface. The interpretation of new gravity data combined with the results of geochemical analysis can be used for more understanding of the geothermal system beneath Gunung Endut prospect area.

  10. ENHANCEMENT OF RECYCLED AGGREGATE CONCRETE PROPERTIES BY A NEW TREATMENT METHOD Download Article

    Ngoc Kien Bui, Tomoaki Satomi and Hiroshi Takahashi
    • Article Type: Research Article
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    • Pages (68-76)
    • No of Download = 350

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    Recently, decreasing natural sources of aggregate accompanied by increasing large quantities of construction and demolition waste (CDW) cause challenges for environment and construction industry. A significant solution for this is to recycle CDW as a new aggregate source for concrete. However, using recycled concrete aggregate (RCA) in concrete involves various obstacles and controversial issues in controlling the quality of recycled aggregate concrete (RAC). This study is an effort to improve the quality of RAC containing 100% coarse RCA by using pozzolanic and sodium silicate solution as new treatment solutions. This study examined performance abilities of RAC after being treated with new treatment solutions and a new mixing procedure. The mechanical properties of RAC were evaluated based on testing of concrete under various conditions. The significant results indicated that sodium silicate combined with pozzolanic materials can improve mechanical properties of RAC containing 100% coarse RCA. At 20% concentration of sodium silicate and silica fume, the compressive strength of RAC could improve up to 36%. Achievements of this approach demonstrated its effectiveness in enhancing the strength of RAC, which is potentially applied to treating RCA for concrete in the future.

  11. UNIAXIAL COMPRESSIVE STRESS-STRAIN BEHAVIOR OF SELF-COMPACTING CONCRETE WITH HIGH-VOLUME FLY ASH Download Article

    Stefanus A Kristiawan, Agus Setiya Budi and Andreas Nur Hadi
    • Article Type: Research Article
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    • Pages (77-85)
    • No of Download = 336

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    Complete stress-strain behavior is a fundamental characteristic of concrete from which principle parameters in the analysis and design of structural concrete elements are developed. It is recognized that the stress-strain behavior of concrete under uniaxial compressive loading is influenced by the concrete constituents. A special type of concrete, i.e. self-compacting concrete (SCC) incorporating high-volume fly ash, has different constituents to that of conventional concrete. For this reason, characterization of the complete stress-strain behavior of this type of concrete is necessary for reliable analysis, design, and utilization of this concrete as a structural element. This research aims to investigate the complete stress-strain behavior of SCC, incorporating a variety of high-volume fly ash (50–70% by weight of total binder) under uniaxial compressive loading. The compression tests were carried out on cylinder specimens of 75×150 mm, where the deformation was controlled at a rate of 1.5mm/min. The results show that at a stress below 60% of peak value, there is a linear relationship of stress and strain. In this state, both global and local longitudinal deformation is quite similar. However, above this stress level, a nonlinearity of the stress and strain relationship exists and local deformation at the fracture zone is higher than global deformation. Various stress-strain models have been used to capture the complete stress-strain diagram of the investigated concrete, using key parameters of the diagram as inputs. Most of the models give a better prediction in the ascending part compared to that of the descending branch. In general, Samani and Attard’s model gives the lowest coefficient of variation of error than other models.

  12. RESEARCH ON CAUSE OF DAM FAILURE FROM VIEWPOINT OF HYDRAULIC FRACTURING – CASE STUDY OF A DAM FAILURE IN VIETNAM Download Article

    Duy Quan Tran, Shinichi Nishimura, Masateru Senge and Tatsuro Nishiyama
    • Article Type: Research Article
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    • Pages (86-94)
    • No of Download = 355

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    It is widely believed 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, a condition which allows for crack propagation in the dam body. The risk of hydraulic fracturing may increase when arching action occurs in the dam body. The aim of this study is to explain the cause of a dam failure using the finite element method. A case study, KE 2/20 REC dam, investigates a dam in Vietnam that failed a little under one year after it was put into operation at positions adjacent to the culvert. A build-up model is taken to simulate the stress-strain state in the dam body. Research reveals that the normal stress around the culvert was reduced to levels much lower than the water pressure. This reduction was due to the arching action associated with the effects of the culvert shape and the foundation. The findings suggest that the cause of the dam failure was related to the hydraulic fracturing phenomenon. Based on this conclusion, two countermeasures are proposed. These countermeasures are combinations created by changing the culvert shape and either shifting the position of the excavation slope 5.0 meters away from the former position or replacing the fill soil between the culvert and the excavation slope with a concrete block. The countermeasures are then verified by numerical models. The results show the effectiveness of the countermeasures for reducing the risk of hydraulic fracturing.

  13. LITTERING BEHAVIOR ANALYSIS BASED ON SURVEY AND QUESTIONNAIRE ABOUT LITTERING IN THE NAGASE RIVER Download Article

    Haruki Shimazu
    • Article Type: Research Article
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    • Pages (95-101)
    • No of Download = 319

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    The present study aims at understanding the quantities and types of litter in and along the Nagase River, and analyzes littering behavior using a questionnaire. Plastic bags, including shopping bags and confectionery wrappers, were the most frequently observed items in the Nagase River. Cigarette-related litter (e.g. cigarette butts and packaging) and drink bottles (e.g. PET bottles, beverage cans) were the most frequently observed types of litter on the streets along the Nagase River. The questionnaires completed by passers-by and students in the schools and a university near the Nagase River were analyzed (N=731). The rate of those who actually littered in the Nagase River and the streets along the river was 14%, and the main kinds of litters were confectionary wrappers, cigarette-related, PET and glass bottles, cans, and plastic bags. The questionnaire results were subjected to covariance structure analysis to determine factors contributing to littering behavior. The results show that, social norms are the most important factor influencing the act of littering, and awareness of the anti-social nature of littering in daily life is strongly related.

  14. ANALYSIS OF THE UNDRAINED SHEAR STRENGTH THROUGH THE STANDARD PENETRATION TEST WITH TORQUE (SPT-T) Download Article

    J.C. Ruge, C.C. Mendoza, J.E. Colmenares, R.P. Cunha and I.F. Otalvaro
    • Article Type: Research Article
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    • Pages (102-110)
    • No of Download = 322

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    Although in situ tests are very useful for obtaining data on the strength and deformation of a geomaterial, some of these tests have been criticized because of their limitations for identifying certain parameters. This paper presents research into a hitherto little used test here in Colombia, the SPT-T (Standard Penetration Test + Torque). This test combines the advantages of the Standard Penetration Test (SPT) and the Vane Shear Test (VST) to obtain a soil’s lateral friction and to correlate its classification and structure by means of the relationship between the NSPT and the torque applied. This study reaffirms the dependent relation between T/NSPT and soil structure found elsewhere in the world and investigates whether parameters governing the undrained condition of soil may be correlated with T/NSPT. Conceptually, a relationship between undrained soil conditions and the way the test is conducted is evidenced. For this reason, this research is an initial approach which open the door to continuing phases of research that may be able to develop appropriate correlations between undrained strengths of soft soils and the T/NSPT parameter used in analyses of this test.

  15. FAULT ANALYSIS IN POHGAJIH VILLAGE, BLITAR, INDONESIA USING RESISTIVITY METHOD FOR HAZARD RISK REDUCTION Download Article

    Adi Susilo, Sunaryo, Fina Fitriah and Sarjiyana
    • Article Type: Research Article
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    • Pages (111-118)
    • No of Download = 211

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    A fault estimation has been done in Pohgajih village, Selorejo subdistrict, Blitar district, Indonesia using geoelectric resistivity, dipole-dipole configuration. The study was conducted using Resistivity meter OYO MacOHm. This study aims to analyze the existing fault track at the study site. The analysis of the fault is expected to provide information on the impact of the settlement of villagers in Pohgajih Village. The data acquisition is performed on five measurement tracks with a track length of 150 meters. Visual surveys show that in Pohgajih Village, there are points where people's homes are fractured and severely damaged, and a slanted electric pole as the ground continues to move every year. Based on the interpretation of the resistivity data and the correlation with the visual survey results, the cracked and severely damaged house points were in the low resistivity range. The resistivity varies from 3.4 to 9.8 Ω.m and interpreted as clay. If traced based on the interpretation of resistivity data and visual surveys then it can be assumed that there is an additional fault, in addition to one track already contained on the geological map. The first fault corresponds to geological information based on the Blitar Sheet Geology Map. However, with the presence of severe damage dwellings at other locations, it is suspected that a second fault is located in the northern part of the first fault. Both faults lead from Northwest to Southeast and are suspected as strike slip fault.

  16. GROUNDWATER FLOW MODELING IN THE WATES COASTAL AQUIFER, KULON PROGO DISTRICT, YOGYAKARTA SPECIAL PROVINCE, INDONESIA Download Article

    Wahyu Wilopo, Doni Prakasa Eka Putra and Dimas Aryo Wibowo
    • Article Type: Research Article
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    • Pages (119-125)
    • No of Download = 306

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    Due to overcapacity, the current airport of Yogyakarta is going to be replaced with a new one, which is located in Wates coastal area, Kulon Progo District, Yogyakarta Special Province, Indonesia. One of the consequences of the development of the new airport is groundwater abstraction due to the airport’s needs and related supporting activities. An excessive withdrawal of groundwater in the new airport will potentially change the system and the pattern of groundwater flow. Therefore, groundwater modeling should be done to predict the impact of groundwater abstraction in this area. MODFLOW code is used to simulate the groundwater flow and the impact of groundwater pumping in the Wates coastal aquifer. The model is calibrated using water level data from 40 wells in the research area. The results show that the calculated values are fit to the measured data, which indicates that the model is reliable. The effects of groundwater pumping on water table and seawater intrusion are investigated using a calibrated model. The results show that the pumping scenario from the airport area causes the groundwater level to drop 0.75 m and seawater intrusion inland to increase around 100 m.

  17. MECHANICAL AND CHEMICAL CHARACTERISATION OF POZZOLAN OF MIDDELE ATLAS IN MOROCCO Download Article

    Azzeddine Bouyahayaoui, Moha Cherkaoui, Larbi Abidi and Toufik Cherradi
    • Article Type: Research Article
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    • Pages (126-134)
    • No of Download = 330

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    This paper presents an experimental study in order to determine the mechanicals properties of the concrete and mortar with pozzolan material. Crushed pozzolan was used as lightweight aggregate and natural sand was used in all mixes to produce a lightweight aggregate concrete. These pozzolanic materials are abundant volcanic area but its use is very limited. The characterizations studies of this material can be useful to product lightweights aggregates concretes, thermal isolated material for energy efficiency in building, environment impact and Sustainable development issues. The properties of hardened and fresh concrete produced from the pozzolan including workability, density, compressive strength, flexural strengths resistance were tested. The chemical, mineralogical analysis, geophysical properties (appearance and shape, natural water content, porosity, density and water absorption) are studied. The properties of the concrete studied were also compared with those of the standard concrete. In order to obtain more knowledge on the mechanicals and chemicals properties of pozzolan concrete, six mixtures were tested: one specimen with Portland cement (control) and tree mixtures with, 25%, 40%, and 100% of pozzolan. Fresh concrete mixtures were tested for workability and density. While for the hardened concrete specimens, compressive strength and flexural strength were determined after 3, 7, 14 and 28 days. X-ray fluorescence, X-ray diffraction and the scanning electron microscope was used to determine the microstructure and to determine the chemical and mineralogical composition of the material. The results of this study show that the replacement of 30% river sand by sand of pozzolan, increase the strength of the mixtures.

  18. EFFECTS OF CHLORIDE CONTENT ON THERMAL PROPERTIES OF CONCRETE Download Article

    David Im, Pakawat Sancharoen, Parnthep Julnipitawong and Somnuk Tangtermsirikul
    • Article Type: Research Article
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    • Pages (135-142)
    • No of Download = 303

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    The thermal properties of cement-based materials have gained more attention not only for the thermal analysis but also for the application of Non-Destructive Tests for building, bridge and other structures. Presence of chloride ions in pore structure was also found to affect thermal properties of concrete. This paper aims to study effects of chloride content on thermal properties of concrete. Specimens were submerged in sodium chloride solution for different period of time. Then, they were subjected to the heating test. It was found out that temperature of specimens with presence of chloride ions in pore solution increased faster compared to specimens without chloride contaminations. As the amount of chloride content in pore structure increased, concrete temperature also rose faster. The results obtained from this study can be used to accurately estimate thermal properties of concrete so that thermal analysis and application of Non-Destructive Tests such as Infrared Thermography can be effectively implemented.

  19. THE EFFECTS OF MAGNESIUM HYDROXIDE FOR THE MICROBIAL COMMUNITY IN THE SEDIMENTS OF A EUTROPHIC CLOSED BAY Download Article

    Dong Xia, Kunihiro Okano, Yukiko Miura, Katsumi Okada, Kunio Watanabe, Rameshprabu Ramaraj andTomoaki Itayama
    • Article Type: Research Article
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    • Pages (143-150)
    • No of Download = 278

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    Bench scale laboratory experiments were carried out to evaluate the effects of magnesium hydroxide (Mg(OH)2) on the sediment quality and on the bacterial communities composition of the sediments collected from a eutrophic inner bay. The pH of sediments in Mg(OH)2 addition treatment group has risen up from the initial value of 7.19 to 8.68 after the 10-day incubation, meanwhile the pH of the control group has stayed around 7.16. The acid volatile sulfides (AVS) content of the treatment group was reduced from initial value of 1.28 mg dry-g-1 to 1.11 mg dry-g-1, though in the control group it raised to 1.34 mg dry-g-1. The dissolved organic carbon (DOC) content increased from 125.3 mg L-1 to 136.5 mg L-1 and 183.9 mg L-1 in control group and treatment group sediments, respectively. Using a next-generation sequencing (NGS) method, it was revealed that the bacterial communities in sediments of the Mg(OH)2 addition treatment group were different from those of the control group sediments. The number of sulfate-reducing bacteria (SRB) such as genus Desulfobulbus in the treatment group sediments has significantly lessened whereas it is elevated in the control group sediments. Redundancy analysis showed that the decrease of AVS in the treatment group was correlated to the reduction of SRB, and the pH increase accelerated the growth of alkaliphilic bacteria (Fusibacter and Alkaliphilus). Moreover, it was speculated that the increase of DOC in the treatment group was due to the up rise of alkaliphilic bacteria and a decline of SRB.

  20. THE IMPACT OF EARTHQUAKES OF TUNNEL LININGS: A CASE STUDY FROM THE HANOI METRO SYSTEM Download Article

    Gospodarikov Alexandr and Thanh Nguyen Chi
    • Article Type: Research Article
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    • Pages (151-158)
    • No of Download = 228

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    At present, systems of infrastructure are built and developed very strongly in Hanoi. The metro tunnels system is also being designed and built in Hanoi to meet the requirements of economic and social development. The paper uses the Wang's method, Penzien & Wu's method, HRM method and a two –dimensional numerical analysis method by Abaqus software to evaluate the impact of the strongest earthquake that could occur in Hanoi to the tunnel lining of Hanoi metro system, this impact could be the internal forces and state stress on the tunnel lining. Based on results obtained from assessing the impact of earthquakes to the tunnel lining in the Hanoi metro system, this paper has compared and commented to these results for the purpose of finding the most accurate results about the impact of earthquakes on the tunnel lining in the Hanoi metro system. These results and comments will be used in the design and construction tunnel in the Hanoi metro system under the impact of the strongest earthquake that could occur in Hanoi.

  21. USING PERMEABLE PAVEMENTS TO REDUCE THE ENVIRONMENTAL IMPACTS OF URBANISATION Download Article

    Oriana Sanicola, Terry Lucke and Jo Devine
    • Article Type: Research Article
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    • Pages (159-166)
    • No of Download = 238

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    Permeable interlocking concrete pavements (PICPs) are being increasingly utilised in urban developments globally to promote stormwater infiltration, reduce catchment runoff volumes and to improve the quality of downstream receiving waters. Increased interest in permeable pavements from planners, designers and stormwater managers has led to an increase in permeable pavement research to try to address some of the common misconceptions and to investigate new research areas. This paper summarises the results of an international literature review that was undertaken to identify and examine the current state of permeable pavement research worldwide. The study found that the stormwater management and environmental benefits of permeable pavements are irrefutable and they clearly reflect the principals of low impact development. However, there are also misconceptions and barriers to their more widespread implementation which need to be addressed to ensure their future as an effective LID solution. More targeted research is required to address some of the outstanding issues with permeable pavements.

  22. ON-SITE VERIFICATION OF REAL-TIME CHECKING SYSTEM FOR IMPROVED RANGE BY HIGH-PRESSURE INJECTING GROUND IMPROVEMENT Download Article

    Hiroyuki Hashida, Shinya Inazumi, Tadashi Chuman and Ikuya Okamoto
    • Article Type: Research Article
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    • Pages (167-172)
    • No of Download = 249

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    In contrast to the mechanical stirring method in which the ground soil and the modifying material are mixed and stirred by stirring blades and the improved body is formed in the ground, the high pressure injection stirring method is a method in which the improved diameter is changed due to soil condition and so on. There is a possibility that it can be changed with, and a method for easily confirming the shape, particularly the improved diameter, is highly desired. In this research, the authors propose and propose a method that can make "visualization" of this improvement situation and confirm the improved diameter in real time. Confirmation was made by measuring water quality in multiple items. From the results, it was confirmed that pH and the values of the other 5 items changed at the same time. And the change was due to the arrival of the cement slurry. Therefore, it can be said that real-time measurement is possible by visualization of improved diameter by water quality measurement conducted this time.

  23. IMPACT OF LAND LEVELING ON THE WATER BALANCE FOR AGRICULTURE IN EASTERN AFGHANISTAN Download Article

    Shakerullah Hashimi, Najumuddin Anjum, Pervaiz Ahmad Naseri and Takamitsu Kajisa
    • Article Type: Research Article
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    • Pages (173-180)
    • No of Download = 240

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    The aim of this study was to investigate the effect of laser land leveling (LL-leveling) on infiltration. Therefore, herein, both the water balance at the land surface and the impact of LL-leveling on infiltration was investigated. The field experiments were comprised of two parts: Farm-A underwent LL-leveling, and Farm-B was used as the control farm with all other practices maintained the same. Also, this research attempts to evaluate the relation of infiltration to field size, water depth (WD), irrigation interval and cultivation age. The findings indicated a fairly negative correlation between field size and irrigation interval; But, a positive association depicted between WD and infiltration. Infiltration has become reduced by increasing field size and irrigation interval. While it decreased by increasing WD. However, cultivation age was not significantly correlated to WD. In addition, the results were summarized on farms basis, in Farm-A, infiltration was shown smaller than that of Farm-B. Moreover, the findings from Farm-A illustrate that, from a water balance perspective, water infiltration was reduced due to larger field size, smaller water input, or prolonged irrigation interval. Hence, in Farm-A, the infiltration was decreased by an average 77%, 25%, and 18 % in the field of corn, eggplant and wheat, respectively. In brief, infiltration is significantly correlated to field size, WD and irrigation interval. Further, LL-leveling has merits to reduce water input, increase the areal size of the field and extend irrigation interval length.

  24. AN INNOVATIVE SANITARY LANDFILL SYSTEM WITH DREDGED MARINE SOILS (DMS) AS LINER MATERIAL: GEO-ENVIRONMENTAL STUDIES Download Article

    Nurasiah Mira Anuar, Chee-Ming Chan and Siti Farhanah S.M. Johan3
    • Article Type: Research Article
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    • Pages (181-185)
    • No of Download = 202

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    The dredging process in Malaysia commonly ends with the dredged material being disposed offshore in designated dumpsite. Nowadays the disposal of dredged marine soils (DMS) into the sea is gradually being discontinued in developing countries due to concerns for the marine environment. Hence, such large volumes of DMS have created a greater challenge for sustainable disposal practice. Recently, a number of studies have reported the potential of DMS as a raw material for transformation into useful products of economical value. Since marine soils such as them are considered harmless, the construction of landfill barriers can be potentially carried out by using this material. This paper aims to determine the ability of DMS to be used as a liner material as geosorbent to remove pathogenic bacteria in landfill leachate. The DMS are subject to a variety of physical and chemical tests. Findings from this study showed that hydraulic conductivity of DMS was within the range stated in the standards for liner material. Based on the result, it is found that the bacteria were able to survive in such extreme salinity at neutral pH condition. Taken together, these results suggest that the use of DMS as liner material in landfill site will help to remove the bacteria in landfill leachate.

  25. EVALUATING THE STATIC AND DYNAMIC MODULUS OF ELASTICITY OF ROLLER COMPACTED RUBBERCRETE USING RESPONSE SURFACE METHODOLOGY Download Article

    Bashar S Mohammed, Musa Adamu and Mohd Shahir Liew
    • Article Type: Research Article
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    • Pages (186-192)
    • No of Download = 201

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    In this study, response surface methodology (RSM) was used to evaluate the effect of partial replacement of fine aggregate with crumb rubber (CR), and the addition of nano silica (NS) by weight of cement in roller compacted concrete (RCC) pavement. Roller compacted rubbercrete (RCR) is used as the terminology for RCC where fine aggregate is partially replaced with crumb rubber. The experiments were designed and analysis executed using the historical data model type. After executing the experimental works, regression analysis was used to develop models for predicting the static and dynamic modulus of elasticity (MOE) of RCR. The RSM regression analysis showed that both static and dynamic MOE decreases with increase in CR replacement level, and increases with increment in addition of NS up to 2%. Therefore CR increases the flexibility of RCR while NS increases its stiffness. The analysis of variance for the developed models showed that the static MOE of RCR can be predicted using cubic model type while the dynamic MOE can be predicted using quadratic model type, with all the models having high degree of correlation and was in agreement with the experimental data.

  26. SUITABILITY EVALUATION OF SPACE UTILIZATION BASED ON ENVIROMENTAL SUSTAINABILITY AT THE COASTAL AREA OF BUNGUS BAY IN PADANG CITY, INDONESIA Download Article

    Dedi Hermon and Aprizon Putraand Olivia Oktorie
    • Article Type: Research Article
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    • Pages (193-202)
    • No of Download = 257

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    This study aimed to evaluate the suitability of space utilization conducted in the coastal area of Bungusbay. The research was conducted through field survey with a spatial approach using Geographic Information System (GIS) in order to know the suitability of area allocations which were served as a protected zone, utilization zone, and special zone. The results showed that zone II covers an area of 232,9 ha with a score of 48,4 and zone II covers an area of 136,2 ha with a score of 23 was not-suitable served as utilization zone, and zone III covers an area of 539,9 ha with a score of 61 was suitable served as utilization zone. Management alternative for not-suitable category in the protected zone at location 8 can be managed by the establishing of coast protection, establishing of stilt house, and the improvement of roads connected to the main road; On the utilization zone of location 11, location 12, location 18, and location 23 can be managed by relocating the settlement as far as >100 m from the coast, establishing of coast protection, establishing of stilt house, and improving roads connected to the main road; On the special zone of location 1 can be managed by relocating the distance limit of ship track and activity, making of settling ponds for waste discharging, and establishing stilt house; and on the special zone of location 25 can be managed by relocating the distance limit of ship track and activity, making of settling ponds for waste discharging, and dust suppression (wetting) during coal loading, and unloading.