Articles
-
ASSESSMENT OF OUT-OF-PLANE FAILURE OF NONENGINEERED MASONRY WALL DUE TO STORM SURGES
- Article Type: Research Article
- View Abstract
- Pages (1-7)
- No of Download = 520
Abstract
Typhoon Haiyan, in 2013, caused massive destruction in the central Visayan region in the Philippines. Failure due to the collapse of non-engineered masonry walls was the most common failure experienced by residential structures in the area. This exposed the high vulnerability of non-engineered masonry walls of residential structures in rural areas against extreme events. Existing building codes for reinforced concrete structures ensure it to perform well against extreme event within Code’s anticipated magnitude. However, masonry walls of low-rise structures along coastal areas did not fare well and exhibited high vulnerability to out-of-plane failures due to poor construction methodology and improper design practice. In this study, on-site survey along coastal barangays of Tacloban City was conducted to determine the method of construction and design consideration for masonry walls. The structural investigation of masonry walls utilized finite element modeling (elastic) and yield line method (plastic). The estimated maximum pressure capacity using yield line method for the non-engineered masonry walls and its compliance to National Structural Code of the Philippines (NSCP 2015)/ACI 530-02 was found to be inadequate. Hence, the improved design was proposed and then assessed against similar loads. Improvements in the design include modification in spacing and size of steel reinforcements, an increase in concrete hollow block thickness, and modifications on masonry wall dimensions. Based on analytical results, the maximum pressure capacity of the improved design increased by 2 to 3 times compared to the current non-engineered masonry wall design.
-
VERTICAL PERMEABILITY OF DREDGED SOIL STABILIZED WITH FLY-ASH BASED GEOPOLYMER FOR ROAD EMBANKMENT
- Article Type: Research Article
- View Abstract
- Pages (8-14)
- No of Download = 484
Abstract
This study presents the vertical permeability and strong relationship of dredged soil stabilized with fly-ash based geopolymer which is to be used for constructing road embankments. The fly-ash used for this study was a low-calcium (Class F) fly-ash. The varying effects on both properties due to the different partial replacements of geopolymer were studied. 10%, 20%, and 30% of the soil sample’s mass were used as a partial replacement. The samples were prepared using the dry-mix method and subjected to 28 days of air-dried curing. Tests like the unconfined compressive strength test and the falling head permeability test were conducted. The morphological features of the samples were investigated using the scanning electron microscopy (SEM). The test results showed that as the percentage replacement of geopolymer increases, the samples become less permeable. SEM analyses confirmed the results, showing that the geopolymer tends to cover up the pore spaces of the soil, causing the water to have fewer passageways.
-
IMPLEMENTATION OF CONNECTION SYSTEM OF WOODEN PLATE AND WOODEN CLAMP ON JOINT MODEL OF BAMBOO TRUSS STRUCTURES
- Article Type: Research Article
- View Abstract
- Pages (15-20)
- No of Download = 467
Abstract
The study of wooden plate bamboo connection system with the addition of wooden clamp was carried out taking into account the variety the angle of the stems at the joint. The loading was preceded through the application of compressive force at the joint’s member understudied up to reaching the maximum load and the connection was collapsed. It is known that the strength of bamboo not parallel to the direction of the fiber is lower than those parallel to fiber. Therefore, the strength of connection must be determined considering the strength of bamboo not parallel to the fiber direction. The experiment was carried out under static loading on the bamboo truss connections model with the various angle of connection stems of 0o, 30o and 45o toward bamboo fiber direction. From the test result, it was found that there is a decrease in the connection strength at stem angle of 30o and 45o for about 16,80% and 12,21%, respectively, compared to the strength of the stem angle of 0o. The test results also resulted the value of average elastic stiffness (Se) of the connection also indicates a decrease in the of elastic stiffness value (Se) of the connection for the stem’s angle 30o and 45o for about 42,62% and 82,95%, respectively, compared to stem angle of 0o. It can be concluded that there is a decrease in the strength and stiffness of the joints along with the increase in stem’s angle of the bamboo truss connection system using wooden plate and clamp.
-
THE ADSORPTION OF HEAVY METALS FROM INDUSTRIAL WASTEWATER USING SARGASSUM CRASSIFOLIUM
- Article Type: Research Article
- View Abstract
- Pages (21-27)
- No of Download = 570
Abstract
Sargassum crassifolium is the origin strains of macroalgae from Indonesia which was the most effectively adsorb heavy metals from liquid solution and it was investigated the adsorptive capability of heavy metals in industrial wastewater. The macroalgae were collected at Kotok Besar Island, Seribu Island, North Jakarta, Indonesia and were treated with the variety of pH 2, 3, 4, 5 and 9 for 60 minutes oscillation, in duplicate assessment. The macroalgae were selectively effective for removal of Cd, Hg, and Pb compared with other heavy metals, achieving 75-99.05% adsorption efficiency, mostly in acidic condition for 60 minutes oscillation, except Hg. The selectivity order for other metal ion uptake by S. crassifolium was Cu>Fe>Co>Ni>Cr with percentage removal below 56%. Due to the low cost, availability and significantly high adsorption capability, the brown macroalgae S. crassifolium is able to be used for selective removal of heavy metals from industrial wastewater effectively in acidic pH range.
-
EFFECTS OF WATERSHED TOPOGRAPHY AND LAND USE ON BASEFLOW HYDROLOGY IN UPSTREAM KOMERING SOUTH SUMATERA, INDONESIA
- Article Type: Research Article
- View Abstract
- Pages (28-33)
- No of Download = 493
Abstract
The characteristic hydrology of a watershed is playing a major role in ensuring water resource availability. Rainfall and runoff responses in catchment area are part of the hydrology cycles. There are several factors to determine the characteristic of hydrology at the watershed, i.e. geological, region, soil and land cover. The existence of water resources is very substantial for surroundings. The rapid development in various sectors leads to water demands increase. Optimum utilization of water resources is needed in the sustainability of water resources or the need for integrated water resources management. The consequence of development is land use change, resulting in changes inflow characteristics, flood during the wet season and drought or discharge decrease in the dry season. Many studies associate higher watershed land cover with lower baseflows, attributed to high evapotranspiration rates, while other studies indicate increased baseflow with higher watershed land cover due to higher infiltration and recharge of subsurface storage. Adaptation and mitigation efforts are required to anticipate changes in the flow characteristics. The factors are key controls on base flow through their influence on infiltration, catchment and subsurface storage properties. This review underscores the need for more research that multiple aspects of the watershed system in explaining base flow. The result of average base flow and total flow ratio during 40 years (1971-2010) is 0.296 and the class of the hydrologic function as a BF / TF ratio value which indicated very poorly hydrology function of upstream Komering, although in certain hydrologic function was still in the good category.
-
DATABASE STRUCTURE OF LAND ALLOCATION MANAGEMENT INFORMATION SYSTEM FOR ESTIMATING RUN-OFF IN WATERSHEDS
- Article Type: Research Article
- View Abstract
- Pages (34-42)
- No of Download = 492
Abstract
Changes in land use are so fast, has changed the pattern of surface drainage (run-off) in the river sub-system area in urban areas. The problem of stormwater is influenced by several factors, such as occupational problems of riverbanks, improper swamps, river tidal influences, which affect the capacity of river sub-systems in the region[1]. This study will discuss the spatial issues in surface water flow systems in urban spatial planning by emphasizing the integration of run-off and land allocation management. The method used in this study is to conduct spatial analysis using all Run-off parameters in the database structure by utilizing the Land Allocation Management Information System (SIMAL) interface built to test the magnitude of flood peaks using the Nakayasu HSS method, with a case study of the Jakabaring river sub-system in the city of Palembang. The results obtained were able to see the conversion of swampland, which was utilized for the Palembang Sports City Region in the face of the 2018 Asian Games in Palembang City, has caused flooding in the Kedukan river region, part of the Jakabaring watershed, Seberang Ulu area, Palembang City, Indonesia. Based on the analysis using the Nakayasu unit hydrograph model, the occurrence of peak flooding will occur when rainfall reaches more than 120 mm / hour which causes the low river discharge to reach up to 400m3/sec. Making artificial lakes as a retention pool and at the same time as a sports venue has not been able to reduce the height of the inundation that occurs around 0.6 - 1.2 m above sea level.
-
IMPROVEMENT OF PUBLIC TRANSPORT TO MINIMIZE AIR POLLUTION IN URBAN SPRAWL
- Article Type: Research Article
- View Abstract
- Pages (43-50)
- No of Download = 465
Abstract
The phenomenon of urban sprawl has been a big issue in big cities of Indonesia since the beginning of the 20th century which has effects on increasing traffic congestion, demand for mobility and air pollution. Air pollution from transportation emission especially in urban areas produces most of the air pollutants and reduces air quality on road corridor. The present study examines the effects due to the improvement of public transport, monorail system in order to minimize air pollution concentration and cost. Air pollution is exhausted from an increase in traffic volume with rising mobility from suburban. Current research is insufficient to reveal the effects of urban sprawl on the cost build-up of air pollution parameters. This study examines to what extent an improvement of the monorail system is able to increase accessibility, reduce air pollution as well as air pollution cost due to housing development in the suburbs of Surabaya City, Indonesia. Comparative analysis was conducted to assess the influences of the design of the monorail system and existing public transport on differences in air pollution cost. The results show that the design of the monorail system has a significant effect on the reduction of air pollution concentration and cost compared to the existing condition. Another result revealed the change of air quality on different road corridor. The reduction of light vehicles due to the design of monorail shows better accessibility and air quality of residents in the western regions of Surabaya City as a case study area in the morning peak hour.
-
PERFORMANCE OF A CIRCULATION TYPE PURIFICATION SYSTEM DURING THE TREATMENT OF SLUDGE FROM MANILA BAY AND TWO PORTS IN JAPAN
- Article Type: Research Article
- View Abstract
- Pages (51-56)
- No of Download = 411
Abstract
Ocean sludge seriously exerts significant environmental load to local sea areas and has a negative effect on the marine ecosystem. In this study, the use of fine-bubble technology for the purification of sludge is being investigated. The principle behind this technology is that the bacteria that can degrade sludge are activated by the aerobic conditions induced by the fine-bubbles. Fortunately, one of the authors successfully developed a fine-bubble decomposition system (circulation type) for ocean sludge. Hence, to verify and check the system’s performance it was used and tested in the treatment of sludge that was obtained from Manila Bay and from Funabashi and Hidaka ports, in Japan. Interestingly, the results of the study showed that the system performed very well in treating the sludge. It is noteworthy to mention that through this study, potentially beneficial bacteria isolated from the sludge sample was successfully identified using 16S rRNA gene sequence analysis.
-
SETTLEMENT BEHAVIOR OF ROAD SURFACES CAUSED BY DISSOLUTION OF SALT LAYERS
- Article Type: Research Article
- View Abstract
- Pages (57-61)
- No of Download = 489
Abstract
This research was aimed at studying the settlement behavior of road surfaces caused by the dissolution of salt layers that in turn create cavities. The dissolution can happen naturally or occur from salt mining. The proposed project’s site was Highway 2229 from km066 +4 to km 275 +4, Kud Ruakham Subdistrict, Ban Muang District, Sakonnakhon Province. The 2015 soil layer drilling survey revealed layers of hard clay and compact soil or shale with low plasticity. Cavities were found at the depth of 42 meters over sand stone layers. The analysis of road surface settlement was based on the Empirical Method and theories of Peck (1969), O’Reilly and New (1982), and Rankin (1969)to determine the i and Vs parameters based on Smsx from the surveys of road surface settlement from 2013 to 2018. Using the survey results, the analysis by the theory of O’Reilly and New (1982) showed i at21 m and Vs ranging from83.24%to85.14%of Vs. The analysis based on the survey data and Rankin’s theory (1969) showed i equal to 19.16m and Vs between 91.23% %and 93.32% of Vs. The analysis of the surveyed data showed the end of surface settlement in 2016, which was consistent with the drilling survey in 2017 from which no cavities were found on the sand stone layers.
-
INFLUENCE OF DENSITY AND THICKNESS ON POLYSTYRENE INSULATED CONCRETE BLOCK WALLS
- Article Type: Research Article
- View Abstract
- Pages (62-67)
- No of Download = 406
Abstract
Expanded polystyrene is known of its useful thermal properties and is widely used as an insulation material. Optimum performance depends on the design and selection of a product. Density and thickness of polystyrene boards were investigated using two chambers built of concrete blocks. The chambers were in the form of four block walls 20 cm in thickness, 1m by 1m size and 1m in height. Wood boards were used in roofs. The two chambers were identical except for insulation arrangements of the blocks. One chamber was built using bricks without insulation while the other chamber involved polystyrene insulated block walls. .In order to assess the influence of density; two types of materials were considered; Wall-mate polystyrene of an average density 26 to 28 Kg/m3 and Roof-mate polystyrene of an average density of 32 to 35 Kg/m3. Boxes of 60 cm x 60 cm x 60 cm made of polystyrene sheets were fabricated with thicknesses of 4, 5, 8 and 10 cm. Ambient temperature and temperature inside each chamber or polystyrene box were recorded using 5TE sensors and a data logger. Hourly records through specified periods of time were logged for the insulation systems used. Temperature changes within the chambers were studied and the influence of the board thickness and material density were reported. It was found that low-density polystyrene provides better insulation. Improvement due to a thickness of polystyrene boards was noted. The results provide a helpful guide for the specification and design works using polystyrene material.
-
ENVIRONMENTAL PARAMETERS CONTROLLING THE HABITAT OF THE BRACKISHWATER CLAM CORBICULA JAPONICA IDENTIFIED BY PREDICTIVE MODELLING
- Article Type: Research Article
- View Abstract
- Pages (68-73)
- No of Download = 358
Abstract
The C. japonica is an ecologically important species in estuaries and brackish waters, as well as a very important fishery resource. However, the relationship between its habitation conditions and environmental factors remains unclear. We therefore made a habitat prediction model using GLM to define the environment of the C. japonica habitat of Lake Shinji, incorporating data acquired from 1982 through 1983 which measured population density, location, silt/clay content, ignition of physical environmental data, pH, dissolved O2 density, chloride ion concentration, and COD of the quality of the water. Our analysis showed that the standardization parameter ignition loss, measuring organic matter and carbonate content in the sediment, was the main effect in the predictive model (estimate -2.22) and had the greatest absolute value. Thus the C. japonica's distribution is dependent on ignition loss, in the predictive model. As for interaction terms modifying distribution, the dissolved O2 and silt/clay content ratio had the largest absolute value at -2.12. In addition, it was revealed that the environmental factors which limit population levels of the C. japonica every season are different. These results, while derived from C. japonica, also suggest that our GLM model is effective to more fully understand the habitation area of immobile benthoses in general.
-
STUDY ON STRENGTH ESTIMATION OF SOIL CEMENT USED IN THE EMBEDDED PILE METHOD BY ELECTRICAL RESISTIVITY MEASUREMENT
- Article Type: Research Article
- View Abstract
- Pages (74-81)
- No of Download = 348
Abstract
Problems caused by poor quality control and quality assurance of the pre-boring embedded pile construction, such as on domestic apartment house are still occurring nowadays. Adequate consideration for invisible risks inside or below the ground is important in pile foundation construction, therefore, the demand for advanced and reliable quality assurance is an increase in the future. In this research, to understand the quality of the construction at an early stage, the compressive strength of cement-soil mixture of pile construction after 28 days is estimated using electrical resistivity value of the mixture. More accurate measurement for electrical resistivity value is conducted by inserting the electrodes without using a potassium chloride solution as a catalyst. The result showed that there is a certain tendency in the electric resistivity value at an early age regarding the type of soil (sand, clay) mixed in. The most accurate estimation was achieved from the electric resistivity value on the first day and several days onwards, and from the compressive strength after 3 days.
-
EFFECTS OF ALKALI-ACTIVATED WASTE BINDER IN SOIL STABILIZATION
- Article Type: Research Article
- View Abstract
- Pages (82-89)
- No of Download = 573
Abstract
Generally, alkali-activated binders have received much attention in recent years due to their energy efficiency, environmentally friendly process, and excellent engineering properties. With respect to this fact, this study aims to investigate the effects of alkaline activation reactions on residual soil by using different percentages of fly ash as a precursor. Precisely, fly ash was incorporated with potassium hydroxide (10M) in order to stabilize the soil and enhance its expediency for various forms of construction. In particular, this experimental study was focused on determining the mechanical performance of stabilized soil. Evidently, the results showed that the different percentages of fly ash (40%, 50%, 60% and 70% by weight) used to stabilize the residual soil affected the unconfined compressive strength of the soil matrix. Also, it was observed that the compressive strength of soil increased progressively with the addition of fly ash. However, the longer the curing period of the stabilized soils, the higher the unconfined compressive strength of the soil. In fact, the microstructural analysis which employed scanning electron microscopy (SEM) revealed the material modifications that can be related to the strength behavior.
-
EVALUATION OF DRAINAGE PROCESS IN POROUS MEDIA BY INVADED PERCOLATION PROBABILITY
- Article Type: Research Article
- View Abstract
- Pages (90-97)
- No of Download = 438
Abstract
Invasion processes, such as the imbibition and drainage processes, through porous media could be modeled using the invasion percolation model in a pore-network that is extracted from actual or virtual packed grains. It is well known that water retention properties depend on pore structures such as pore shape, pore-size distribution, and pore-connectivity. However, in our previous work, it is confirmed that there is a spatial structure even in a porous medium packed with single-size grains, and that if the spatial structure of the pores is not disturbed, different water retention curves obtained from different pore-size distributions for the imbibition process can be unified into a single curve using the invaded percolation probability (IPP). This is the proposed evaluation method based on the percolation probability (PP). In this study, the drainage process is evaluated using water retention curves and the IPP through numerical experiments. The results show that the different water retention curves were unified into a certain curve based on the PP when the IPP based on pore body and pore throat was employed. Using this evaluation method, we can obtain additional information regarding the proportion of potentially invadable and actually invaded pores and the degree of their spread in the porous media. Hence, it is concluded that this method could be a very useful tool to grasp the state of porous media.
-
DAMAGE DETECTION AND LOCALIZATION IN MASONRY STRUCTURE USING FASTER REGION CONVOLUTIONAL NETWORKS
- Article Type: Research Article
- View Abstract
- Pages (98-105)
- No of Download = 499
Abstract
With current modern technology, manual on-site inspection can be assisted by automatic inspection, which is cost-effective, efficient and not subjective. In previous work, various image-based techniques have been applied to detect damages in heritage structures based on hand-designed feature extraction and classifiers. A heritage structure is composed of masonry walls, which are the components that are typically subjected to severe damages. This paper proposed a damage detection algorithm for a masonry structure based on Faster Region Convolutional Neural Networks (FRCNN). A labeled dataset for training the damage detection system in heritage masonry structure is created in this study, which is our first contribution as, currently, there is no public dataset available for masonry structures. The second contribution is the creation of a state of the art object detection system based on FRCNN for the detection and localization of damage in masonry structures. The results show that the proposed system performs well and can be used to detect damage in masonry structures with promising computational speed.
-
STRUCTURAL EVALUATION OF NURUL HAQ SHELTER BUILDING CONSTRUCTED ON LIQUEFACTION PRONE AREA IN PADANG CITY - INDONESIA
- Article Type: Research Article
- View Abstract
- Pages (106-114)
- No of Download = 489
Abstract
West Sumatra Province, especially Padang City, is an area prone to the earthquake that is not only can trigger a tsunami but also liquefaction disaster. In order to face the disaster, the Padang city government planned to build as many as shelters as a vertical evacuation building. One of them is Nurul Haq shelter located in a coastal area that has high liquefaction potential. A structural evaluation of the shelter was conducted to check the capacity of the existing shelter structure in resisting the working loads. From the result of the soil evaluation, it was found that the soil in the shelter location has high liquefaction potential. Therefore, the shelter structure is analyzed using specific response spectrum of the earthquake loads considering soil liquefaction, which is 1.5 higher than those on the non-soil liquefaction. The tsunami loads were calculated used based on FEMA P-646. The analysis result shows that the shelter building is not capable of resisting the working loading, in which the elements of the beams and foundations don’t have enough capacity to resist the working loads, especially earthquake and tsunami loads. Furthermore, the shelter building should be retrofitted before being used as a vertical evacuation building.
-
TESTING OF FOAM CONCRETE FOR DEFINITION OF LAYER INTERACTING WITH SUBSOIL IN GEOTECHNICAL APPLICATIONS
- Article Type: Research Article
- View Abstract
- Pages (115-120)
- No of Download = 481
Abstract
Today’s production of foam concrete (FC) has become more suitable for various types of applications due to the usage of new additives and improved technology. One typical application of foam concrete in Europe is the creation of a sub-base layer of the floor of multi-storey buildings, where thermal and noise insulation functions are required. The main advantage of foam concrete production is its unlimited variety of desired properties, which must be properly balanced for a specific application and its interacting structure. Produced FC can have unit weight from 300 to 900 kg.m-3, compression strength from 0.4 to 12 MPa, elasticity modulus from 1200 to 2500 MPa and coefficient of thermal conductivity from 0.15 to 0.30 W.m-1K-1. Thanks to these properties, FC can be used for the construction of foundation slabs of passive houses, as a sub-base layer of industrial floors and as a filling material of narrow excavated shafts. As for concrete, reinforcement can improve tensile properties, but due to corrosion, iron bars or nets must be replaced by special material bars, nets, geogrids or geotextiles. For the mentioned type of structures and loading of FC layers, the importance of laboratory and in-situ testing is crucial. This article presents laboratory tests of one of the selected parameters, which is flexural strength of FC in various unit weights, and demonstrates a significant improvement of strength when non-woven geotextile and mesh type reinforcement was used. Use of geotextile at the bottom part of samples increased flexural strength from 30 to 60%, mesh reinforcement can have doubled basic flexural strength. Crack propagation with respect to time was also observed during tests in order to compare the results of reinforced FC with no reinforced layer.
-
DEVELOPMENT OF GREEN INFRASTRUCTURE IN URBAN CATCHMENT AREA (CASE STUDY: TANJUNG BARAT SUB-DISTRICT, SOUTH JAKARTA)
- Article Type: Research Article
- View Abstract
- Pages (121-126)
- No of Download = 422
Abstract
The rapid urbanization of the city of Jakarta has resulted in the decreasing of the hydrological function of the city due to the increase of impervious land cover and the reduced water catchment area. Water conservation efforts are needed by increasing water infiltration and reducing surface water runoff with the Low Impact Development approach with green infrastructure (GI) implementation in the urban catchment area. This research takes a case study in Tanjung Barat Sub-district, South Jakarta, which acts as one of the water catchment area of Jakarta. The aims of this study are to determine the placement of GI in accordance with the criteria of land suitability and analyze the effectiveness of its application. The method used in this research is the modeling of GI placement by using BMP Siting Tools module on the SUSTAIN program and ArcGIS. And its effectiveness analysis with the calculation of flow coefficient and flow of runoff. The study result showed some of GI types that suitable to be implemented are bioretention and rain barrel. Based on the calculation of flow coefficient and runoff flow, it is known that GI application is effective in lowering the flow coefficient and reducing runoff discharge by 26.25%.
-
CONSTRUCTION OF EARTH FILL STRUCTURE FOR SMALL FARM POND BY USING BHUTANESE TRADITIONAL WALL MAKING METHOD
- Article Type: Research Article
- View Abstract
- Pages (127-132)
- No of Download = 390
Abstract
The Kingdom of Bhutan has mountains as high as 7,000 meters height at the east end of the Himalayas and the semitropical region at an altitude of 100 meters in its south area. Because of its precipitous terrain, stable supply of water for irrigation is difficult without efficient water supply system such as reservoirs, pipelines and so on. Based on the results of preliminary field investigations, existing reservoirs in the Kingdom of Bhutan often have structural problems in its body and foundation. To contribute to an increase in agricultural production in the Kingdom of Bhutan through the development of construction techniques for reservoirs, an earth fill structure for small farm pond was suggested and constructed in 2015. In this construction, Rammed earth method, which is well known as Bhutanese traditional wall making method, was applied as a compaction technique of soil. Authors conducted a follow-up of the earth fill structure in September 2017 to confirm the performance of the wall making method as a construction technique for reservoirs. Based on the results of the portable dynamic cone penetration tests, it is supposed that this rammed earth method couldn’t achieve sufficient compaction energy for construction of earth fill structures for reservoirs because observed N values were comparatively small compared with that obtained from embankments constructed by modern compaction techniques. Therefore, in the construction of earth fill structures for farm pond by utilizing the rammed earth method, improvement in compaction technique should be considered.
-
RESISTIVITY AND CHARGEABILITY SIGNATURES OF TSUNAMI DEPOSITS AT ACEH BESAR AND BANDA ACEH COASTAL AREA, INDONESIA
- Article Type: Research Article
- View Abstract
- Pages (133-143)
- No of Download = 509
Abstract
The study was conducted at the coastal area of Aceh Besar and Banda Aceh using 2-D resistivity and IP methods to investigate the changes/response of resistivity and chargeability toward sediment. The study is aimed to identify the post-, pre- and tsunami sediment deposits. The results are validated with hand auger performed on the study line. Generally, the study identified that the coastal sediments of Aceh Besar and Banda Aceh consist of clay/silty clay/sand/silty sand. Based on the results, the sediments are categorized into three layers; the top layer (post-tsunami sediment), tsunami sediments and pre-tsunami sediments. The tsunami sediment consists of a mix of sand or clay or silty clay or silty sand. Each layer was represented by different resistivity and chargeability values depending on the sediment types.
-
SEA-LEVEL RELATED ENGINEERING GEOLOGY AND INTRINSIC COMPRESSION BEHAVIOUR OF BANGKOK CLAYS
- Article Type: Research Article
- View Abstract
- Pages (144-153)
- No of Download = 366
Abstract
All the important infrastructures in Bangkok city are founded in soft, stiff to hard clay layers up to 80 m deep. The engineering properties of these clays depend a lot on their microstructure, which in turns is a result of geological conditions governing the deposition and subsequent geological processes of loading, unloading and weathering. Thus, a study of soil microstructure would help understand better the soil engineering properties to be used in geotechnical analyses. In this paper, a detailed review of sea level-related engineering geology of the depositional environment of Bangkok clays was made. Geotechnical boreholes were drilled at six testing sites as part of a groundwater recovery study project, from which samples of Bangkok clays were collected up to 80 m deep and tested. Based on the results of an integrated geological-geotechnical analysis the microstructure of Bangkok clays was indirectly investigated via their intrinsic compression behavior and in-situ state. It was found that the Soft Bangkok clay at depth 4-11m (SOCL) is a bonding-dominated or cemented clay with a meta-stable structure, whereas stiff clay at depth 12-24m (STCL), the first hard clay at depth 30-50 m (HCL01) and the second hard clay at 50-80 m (HCL02) are fabric dominated with a stable structure. On the plots of void index versus depth the in-situ state the Bangkok soft clay lie in the sedimentation compression range, the stiff clay and the first hard clay lie both in sedimentation compression and overconsolidated clay ranges, while the second deeper hard clay (HCL02) lies only in the overconsolidated clay range.
-
APPLICATION OF DIGITAL ELEVATION METHOD ( DEM ) FOR FLOOD ESTIMATION ON UPSTREAM CILIWUNG RIVER, WEST JAVA, INDONESIA
- Article Type: Research Article
- View Abstract
- Pages (154-165)
- No of Download = 311
Abstract
Flood generally caused by the high speed of urban growth that is not balanced by efforts to avoid it. The decrease of vegetation closing and the disappearing of the natural reservoir can cause the lack of field ability to restrain rainfall and disturb surface stream flow that influences the balance of hydrology along the river basin. Hydrology models tended to be spatially distributed. By computer support with higher memory capability and faster speed, the increase of development and usage of spatially distributed models substitute lump parametric models or aggregate to spatially simple. Furthermore, there are many efforts of integration forms, either database or hydrology models with Geographic Information System (GIS). The approach of the integration of spatially distributed hydrology model and GIS is used to simulate the hydrology process interactively with the basis of spatiotemporal, with a variety of land use, rainfall, and detention reservoir volume changes (embuing/ small dam). The DEM which emerges land surface morphology information is used to represent hydrology process of surface runoff. Topography structure extraction algorithm will be the slope and the current direction is an important factor in describing drainage network. The elevation numbers and its descendants are depicted in grid cells in 50 m x 50 m measurement. The result shows such as in flood hydrograph which is varied base on land use, design rainfall and detention reservoir (embung/ small dam).
-
INFLUENCE OF CLAY CONTENTS ON DRAINED SHEAR STRENGTH PARAMETERS OF RESIDUAL SOIL FOR SLOPE STABILITY EVALUATION
- Article Type: Research Article
- View Abstract
- Pages (166-172)
- No of Download = 318
Abstract
Consolidated drained triaxial compression tests (CD) were conducted to determine the compression properties of remolded samples collected from hillslope in residual soil. The test results showed that the effective drained shear strength of residual soil was primarily affected by the degree of weathering according to depth, parent rock material, and clay contents and also influenced by initial moisture content. These samples were classified as silt soils of high to low plasticity. CD tests were performed on samples prepared under 100 and 200 kPa remolding pressure with three different confining pressures of about 50, 100 and 150 kPa. Predicted results showed that the soil strength increased with increasing samples’ density for those who prepared with a higher remolding pressure. According to the soil composition, a clear decrease in soil cohesion was observed for samples collected at a deeper depth, while a further increase in the effective internal friction angle was observed for samples collected with a lower depth. However, this explains the significant influence of clay contents that can be represented as a relevant relation. Therefore, the results indicated that the studied residual soils have physical and geotechnical properties that are highly dependent on the clay and initial water contents. Then, the concept of long-term stability analysis of hillslope of Balai Cerap area (in UTM/ Malaysia) was presented in the form of factors of safety as discussed later in this study by employing Geo-Studio program (SLOPE/W application) with Limit Equilibrium Method.
-
THE COMBINED EFFECTS OF NANO-MONTMORILLONITE AND HALLOYSITE NANOCLAY TO THE WORKABILITY AND COMPRESSIVE STRENGTH OF CONCRETE
- Article Type: Research Article
- View Abstract
- Pages (173-180)
- No of Download = 283
Abstract
In consideration of higher specifications for concrete, particularly in strength, the proportion of ingredients is usually modified to satisfy the mix design requirements. However, its practicality is not always appropriate in construction because of the expense and availability of the materials. Hence, additives and supplementary materials are adopted in the mix design with present studies directed to the application of nanoclay constituents to concrete technology. Consequently, the study is concerned with the utilization of nano-montmorillonite and halloysite nanoclay as partial substitutes to cement in which the workability and compressive strength of concrete are investigated at combined replacements of these nanoclays. The results show that the workability of fresh concrete generally decreased at the addition of nanoclay in the mix wherein a maximum loss of 50.000 % in the slump is observed for 5% replacement of the nanoclay combination. In addition, a 28th-day compressive strength of 44.541 MPa is achieved as the highest among the concrete samples at 3% replacement which demonstrates an increase by 27.430 % compared to a control specimen with a strength of 34.954 MPa. It is also recognized that there is a parabolic trend of compressive strength with respect to the amount of nanoclay replacement which indicates that the strength of concrete continues to increase until the optimal value of nanoclay replacement is attained. It is established that the optimal replacement of nanoclay combination for a curing period of 28 days is 2.562 % corresponding to a theoretical peak value of 46.060 MPa.
-
VALIDATING THE CURVE OF DISPLACEMENT FACTOR DUE TO FULL SCALE OF ONE PILE ROW NAILED-SLAB PAVEMENT SYSTEM
- Article Type: Research Article
- View Abstract
- Pages (181-188)
- No of Download = 258
Abstract
A proposed alternative solution for rigid pavement problem on soft soil is the pavement of Nailed-slab System. It is a kind of developing the rigid pavement. Equivalent modulus of subgrade reaction (k’) can be used to analyze Nailed-slab System. This modulus consists of the modulus of subgrade reaction from plate load test (k) and additional modulus of subgrade reaction due to pile installing (Δk). The Δk can also be determined by using the curve of the displacement factor. This research is aimed to validate the theory of additional modulus of subgrade reaction by using the curve of displacement factor due to the results of a prototype test of Nailed-slab with 1 pile row. The prototypes were constructed on soft clay and the connection between pile and slab was perfect monolithically. These systems were loaded by monotonic loads. Calculated deflections based on the method of the additional modulus of subgrade reaction were compared to the observed deflection and the results from the Finite Element Method. The result shows in good agreement with the observation. The proposed method of analysis was practical in use and timeless consuming. Designing the Nailed-slab by considering a single pile row which used k’ will result in design in the safety zone.
-
EVALUATION OF PHYSICAL DEVELOPMENT OF THE COASTAL TOURISM REGIONS ON TSUNAMI POTENTIALLY ZONES IN PARIAMAN CITY- INDONESIA
- Article Type: Research Article
- View Abstract
- Pages (189-196)
- No of Download = 328
Abstract
The purpose of this research is to determine the location of evacuation lines, TES or assembly points and shelters, and knowing the extent of the distribution of coastal tourism regions, as well as the distance of evacuation routes to TES or assembly points and shelters when tsunami occurs through the creation of a zoning model of coastal tourism-based disaster mitigation regions in Pariaman City. Methods in this research, i.e determining the location of TES or assembly points and shelters, and determine the capacity of TES or assembly points and shelters. Data processing and analysis for determining location, the capacity of TES or assembly points and shelters through the GIS approach. The results showed the tourism region of Gandoriah beach (7.8 Ha) an average tourist visit in 1 month in 2017 as many as 89.188 people/month with the number of TES or assembly points 2 and shelters 2, the tourism regions of Anas Malik and Cermin beach (16.11 Ha) an average tourist visit in 1 month in 2017 as many as 55.743 people/month with the number of shelter 1, the tourism region of Kata beach (19.68 Ha) an average tourist visit in 1 month in 2017 as many as 44.594 people/month the number of TES or assembly points 3 and does not have a shelter; and the tourism region of Naras beach (7.54 Ha) an average tourist visit in 1 month in 2017 as many as 33.445 people/month with the number of TES or assembly point 1 and shelter 1.
-
REVIEW COLLAPSE MECHANISMS CAUSING DAMAGE FROM CONTROLLED AND UNCONTROLLED DEMOLITIONS
- Article Type: Review Article
- View Abstract
- Pages (197-203)
- No of Download = 257
Abstract
To design for blast, ballistic or seismic loadings an engineer needs to know the collapse mechanisms of all forms of typical building systems whether residential or commercial in order to have the technical capacity to design against such loadings. Once the engineer becomes aware of the collapse mechanisms that are likely to cause damage through blast loadings that will be applied to a structure by a controlled demolition or an uncontrolled demolition (terrorist attack), a position is reached whereby the design process can commence to not only accommodate the overpressures but also, through design, inhibit or delay collapse so those caught within the building can escape to safety before total collapse occurs. In most such cases death or injury occurs primarily because of the collapse of structures and not because of blast, ballistic or seismic loadings applied to it. In most building systems there are structural entities that are present for specific structural reasons but nevertheless are problematic in that they can inhibit progressive collapse. These problematic structural entities need to be understood in detail and addressed both in controlled and uncontrolled demolitions to be able to achieve a progressive collapse. 3rd world countries see most buildings damaged by the blast, ballistic and seismic loadings as design standards either don’t exist or are not policed by local government instrumentalities thus leading to excessive damage, death or injury.
-
DELINEATION OF SUBSURFACE STRUCTURES OF SEMANGGOL FORMATION, NORTH PERAK USING MAGNETIC DATA
- Article Type: Research Article
- View Abstract
- Pages (204-209)
- No of Download = 457
Abstract
The Semanggol Formation has been studied widely and published by many, but only focus on areas of northern and southeast Kedah. Limited data have been studied and published on Perak area, especially Gunung Semanggol. The research is aimed to augment the presently limited knowledge on the hill, particularly the subsurface structure. In addition, new lithology such as a breccia formation with tens of meters width of what appears to be a breccia granitic matrix was identified in an abandoned quarry. Therefore, a study on the application of geophysical methods covering the Semanggol Formation located at Semanggol area has been carried out. The main aimof this study was to conduct a magnetic survey to study the subsurface and possibility of granitic bodies in Gunung Semanggol. The total magnetic field data were obtained by using a proton free-precision magnetometer, recording the total ground magnetic field along the transverse. There was a total of 184 magnetic stations established during the survey with a 500 m to 1 km spacing. Data reduction was processed using Oasis Montaj software to produce Total Magnetic Intensity (TMI), Reduction to Pole (RTE), Regional Anomaly and Residual Anomaly maps for qualitative interpretation. The interpreted field data gave the results of total component measurements of magnetic anomaly varying between minimum negative value around 180 nanoTesla (nT) and maximum around 510 nanoTesla (nT) as shown in TMI map. Besides, the regional magnetic map shows a gradual decrement of magnetic intensity towards east and southeast. And residual magnetic map reveals that the dominant orientation for magnetic lineaments in the NE-SW direction. However, geochemical tests have to be conducted to study the possibility of granitic bodies.
-
THE FLUCTUATION OF DOMESTIC WASTEWATER DISCHARGED FROM OFFICE BUILDING
- Article Type: Research Article
- View Abstract
- Pages (210-215)
- No of Download = 559
Abstract
The domestic wastewater from office building has been recognized to be different to other sources of wastewater discharge. The objectives of this research were to know the fluctuation of quantity, fluctuation of quality, and the peaking factor of wastewater discharge. The samples were taken from hourly sampling and daily sampling from 7 am to 5 pm and from Monday to Friday during the working time. The results showed that wastewater discharge varied over time and the quantity of Blackwater, greywater and mixed wastewater were ranging from 20.4 to 22.6, 18.7 to 23.3 and 39.61 to 49.93 liter/person/day, respectively. The quality of mixed wastewater varied over time such as for COD, TN, and TP was 252.45±88.96, 85.42±24.08 and 3.01±1.92 mg/L (mean± standard deviation), respectively. The low concentrations were in the morning and peak concentrations were in the afternoon after lunch time. The peaking factor of Blackwater, greywater and mixed wastewater discharge were 1.67, 1.6 and 1.83 at the beginning of working time and the praying time of Muslim Indonesian culture, respectively. It is proposed that domestic wastewater from office building has specific characteristics and the findings of this research can be served as useful information for designing of domestic wastewater treatment system for office buildings.
-
THE DEVELOPMENT OF JOB COMPETENCY FOR SKILLED TECHNICAL WORKER TOWARDS GREEN TECHNOLOGY
- Article Type: Research Article
- View Abstract
- Pages (216-221)
- No of Download = 484
Abstract
Promoting green technology to protect the environment is a major challenge in the current world. Human activity that affects the environment must be designed with a proper manner to ensure that the effort to maintain good practices is achieved. Referring to the above matter, an individual that entering the industry must be equipped with adequate skill and knowledge related to green skills. However, the scenario shows those individuals that enter the labor market without a relevant qualification is common in Malaysia. In the labor market, these individuals are considered to be low-skilled workers because they had no training prior to employment. Therefore, specific training needs to be prepared for them to increase their skills. Therefore, this research is conducted to develop a job competency for these groups of workers pertinent to its aim towards sustainable development. This research provided an opportunity to examine an enterprise-based approach to skill formation for workers with basic academic qualifications. Curriculum Development Based on Ability Structure (CUDBAS) methodology is used for this research where a structured curriculum development of human resources learning needs will be designed according to the job profile of the typical individual and group work. It will provide a clearer perspective on knowledge, competence and skill levels of employee behavior in performing tasks. The biggest impact on this study is to produce high skill employees concerning customer satisfaction and increased organizational productivity towards high-income nations.