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INDONESIA
Journal of the Civil Engineering Forum
Published by Universitas Gadjah Mada
ISSN : 25811037     EISSN : 25495925     DOI : -
Core Subject : Social, Engineering,
Civil Engineering, Building, Construction & Architecture Environmental Science
Journal of the Civil Engineering Forum (JCEF) is a four-monthly journal on Civil Engineering and Environmental related sciences. The journal was established in 1992 as Forum Teknik Sipil, a six-monthly journal published in Bahasa Indonesia, where the first publication was issued as Volume I/1 - January 1992 under the name of Forum Teknik Sipil.
Arjuna Subject : -
Articles 225 Documents
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The Utilization of Soybean as a Catalyst Material in Enzyme-Mediated Calcite Precipitation (EMCP) for Crack Healing Concrete Regina Aprilia Zulfikar; Heriansyah Putra; Hideaki Yasuhara
Journal of the Civil Engineering Forum Vol. 7 No. 1 (January 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.57889

Abstract

The effect of using soybean as a catalyst in the Enzyme-Mediated Calcite Precipitation (EMCP) method of crack healing concrete is discussed in this research. The existence of cracks in concrete reduces its quality, therefore, there is the need for repair efforts and one of these is through injection using the EMCP method. This technique employs the plant-derived urease enzyme to catalyze the reaction between calcium chloride (CaCl2) and urea (CH4N2O) towards precipitating calcium carbonate (CaCO3). Its effectiveness was, however, evaluated using a test tube experiment, and the optimum combination of urease, urea, and calcium chloride was selected and used as the preliminary data for the soybean added as a catalyst. Meanwhile, the concrete samples were prepared in the form of 5 cm x 10 cm cylindrical concrete and the crack was made through Universal Testing Machine (UTM) with a controlled area observed to be in the range of ± 0.2-0.3 mm. The injection solution was added to the concrete using the percolation method up to the period the height of the solution was 5 mm above the concrete surface and this was conducted several times with the effect on the concrete cracks evaluated through permeability tests which were used as one of the concrete quality parameters. Moreover, the permeability coefficient value was found to be inversely proportional to the quality and this means a smaller value of the coefficient produced better concrete quality and vice versa. The results showed the total calcite formed in the sample after the 4th injection was 18.3% of the total surface area of the concrete crack and was able to reduce the concrete permeability value by 95.43%. This, therefore, means the use of soybean in the EMCP method is considered feasible to repair concrete cracks.
The Application of Combined Phytoremediation Greywater Treatment in A Single House Ni Nyoman Nepi Marleni; Ristie Ermawati; Nurul Alvia Istiqomah
Journal of the Civil Engineering Forum Vol. 7 No. 1 (January 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.58218

Abstract

A report showed 22% of households in Indonesia did not have a proper sanitation facility in 2018 and this caused the potential discharge of their wastewater directly to the surface water, thereby, polluting the water and its surrounding environment. The quality of water resources is also declining nationwide due to pollution and this affects the cost of water treatment, therefore, it is necessary to determine the most effective treatment method to reduce this pollution. However, one of the breakthroughs observed to have met the criteria of low cost, simple operation and maintenance, and energy-saving is greywater treatment using plants (phytotechnology) combined with solar ultraviolet (UV) system. This research was, therefore, conducted to evaluate the performance of the coupled greywater treatment and investigate the possibility of its implementation in the actual condition of a selected single house. Moreover, the physical treatment and phytoremediation were combined with solar disinfection treatment, and the units selected include a collection and sedimentation chamber, filter, phytoremediation, and solar disinfection chamber. The flowrate was measured based on the difference in water level over time while the influent and effluent quality was evaluated at the inlet of the sedimentation chamber and outlet of the disinfection chamber. The results showed the organic efficiency removal was up to 92% while the solids content was found to be high at 49% and the system was able to effectively remove the ammonia at 57% and reduce the pathogenic bacteria by 88%. Moreover, the treated water quality known as the effluent met all the requirements of the Provincial Regulation of Central Java No. 5 of 2012 and Class 3 standard (water for cultivation of plants and fisheries) of Indonesian Government Regulation No. 82 of 2001. However, it did not meet the standard for toilet flushing water according to the standard from U.K, U.S.A, and Australia. This means the treatment system was unable to produce an effluent with the ability to replace the water use indoor. Therefore, it is recommended that an advanced treatment system for greywater such as Submerged Membrane Bioreactor be applied to maximize the intake of treated greywater for indoor and outdoor uses.
The Effect of Slope on the Infiltration Capacity and Erosion of Mount Merapi Slope Materials Adam Pamudji Rahardjo; Anselma Diksita Prajna Duhita; Ani Hairani
Journal of the Civil Engineering Forum Vol. 7 No. 1 (January 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.58350

Abstract

The infiltration on slopes has a specific behavior capable of being parameterized and one of the reasons is due to the ability of the slope to generate less ponding on the sloping soil surface. This, therefore, affects infiltration rate and surface runoff proportion of water from any kind of rainfall distribution and the tendency of the surface runoff to be higher usually leads to a higher erosion rate on the slope. Moreover, slope steepness is the most important parameter of a slope, and its effect at 36%, 47%, and 58% was tested on the infiltration capacity and erosion rate of Mt. Merapi bare slope material in a laboratory using a rainfall simulator. The rainfall intensity was set constant at a rate of 116.31 mm/hour while the infiltration rate was measured by the volumetric balance principle and the erosion rates by collecting the eroded grains at the downstream end flume. Furthermore, the infiltration capacity was evaluated using the Horton method by fitting the equation to the recorded infiltration rate data while the average erosion was through the eroded grain data for each test. The results obtained represent the relationship between slope steepness, the affected infiltration capacity, and erosion for each test, and the infiltration capacity was found to be decreasing in lower slope < 47% and increasing in a higher slope while the erosion rate was increasing between 7% and 15% for each 1% increase in the slope steepness. In addition, polynomial and linear equations were developed to express the relationship between these three indicates at the Mt. Merapi bare slope material.
Determination of Optimal Rain Gauge on The Coastal Region Use Coefficient Variation: Case Study in Makassar Giarno Arno; Muflihah Muflihah; Mujahidin Mujahidin
Journal of the Civil Engineering Forum Vol. 7 No. 2 (May 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.58378

Abstract

The quality of rainfall data is highly significant in disaster analysis, ecology, and water resource management. However, the accuracy and quantity of rain gauges are often inadequate, especially for analyzing extreme events, including the Makassar City flood, in 2019. This inadequacy is due to several reasons, including rain gauges’ inadequacy and insufficient distribution. This study, therefore, aims to analyze the requirements of optimal rain gauges, using coefficients of variation in various error levels, based on the latest rainfall data in several locations within Makassar City. Monthly and yearly rainfall observation data from 2010 to 2019 obtained at 5 locations were used to calculating the optimal rain gauge number. According to the results, the existing station has a 10% and 15% monthly and annual error, respectively. This region has 3 groups causing highly optimal rain gauges, and these are the first group comprising Paotere, Panaikang, as well as Biring Romang, while the second and third groups comprise Sudiang and Barombong. The northwest wind blows towards the coast and crosses these three places in a line, thus, causing rainfall intensity with a slight disparity, between the first group. Furthermore, the combination of these places resulted in low optimal rain gauge. However, the combination of the first group with the second and third lead to an increase in the optimal rain gauge number. The low elevation, proximity, and location of the first group’s three locations in line with the rain-causing wind results in low optimal rain gauge. In the combination of the first, second, and third groups, additional gauges are required to obtain a 5% or 10% error. The rainfall intensity and position greatly influence the rain catchment in Makassar, and consequently, the optimal rain gauge number. In addition, the distance, topographical aspects, and the combined land-sea and monsoonal winds’ factors must also be analyzed, in deploying equipment.
Evaluation of Reservoir Capacity and Reliability for Urban Water Utilization in Dili, Timor Leste Aderita Mariana Takeleb; Joko Sujono; Rachmad Jayadi
Journal of the Civil Engineering Forum Vol. 7 No. 2 (May 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.58538

Abstract

The ability to store and distribute water resources is very significant to human activities. Therefore, high importance is placed on the sector to address any adverse impact in the event of major shortfall, particularly in Dili, Timor Leste. A study on the development of effective water resource management mechanisms has been conducted to support government visions. As a consequence, priority strategy was initiated to design the necessary infrastructure, in order to match urban demands. One action plan of this effort is by building reservoirs. The purpose of this study was to evaluate the construction of a minor or large reservoir to meet water consumption rate in Dili. Also, the strategy implementation proposal of the reservoir development in Beemos and Becora rivers was prepared by analyzing the reliability and capacity, using a model known as water release standard operating rules. However, water balance simulation results showed the reliability of clean water services from these two small storage units is unable to approach 100%, due to limited volume. The capacity optimization outcomes of large Beemos reservoir indicated the inflow potential at 90% utilization, and therefore is able to balance the urban water demand up to 2030. Despite impressive simulation results, the government is expected to consistently conduct a detailed feasibility study in the upstream area, prior to implementation. Furthermore, large reservoir construction is highly recommended for effective water resource expansion, in an attempt to match the high consumption rate in Dili. This effort possibly supports Timor Leste's targets and sustainable development goals concerning clean water and sanitation.
The Influence of High Plasticity and Expansive Clay Stabilization with Limestone on Unconfined Compression Strength Soewignjo Agus Nugroho; Gunawan Wibisono; Andarsin Ongko; Avrilly Zesthree Mauliza
Journal of the Civil Engineering Forum Vol. 7 No. 2 (May 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.59438

Abstract

Clay is a cohesive material that becomes very soft when high content of water is added. This condition makes construction activities difficult on this type of soil. There is, therefore, a need for stabilization when dealing with high plasticity clay through several methods such as the application of limestone. However, this method mostly does not meet the standards due to the reaction between limestone and groundwater which normally alters soil properties, thereby, leading to a reduction in stickiness and softness of the soil. Meanwhile, limestone generally has the ability to compact and stabilize the soil due to its fine powder which consists of metals and non-organic mineral compositions. Therefore, this study was conducted to identify the influence of using limestone additives for stabilization at different mixture compositions on clay. The properties of the soil were tested before the Unconfined Compression Strength Test and the results showed limestone was effective in stabilizing high plasticity and expansive clay. This was proven by the 10% increase in the Unconfined Compression with lime content in curing conditions for 28 days as well as the 319% magnitude of the non-soaked, 6% reduction in the liquid limit value, and 46% increment in the plastic limit value.
Physical Modelling of Earthquake-induced Liquefaction on Uniform Soil Deposit and Earth Structures Settlement Avantio Pramaditya; Teuku Faisal Fathani
Journal of the Civil Engineering Forum Vol. 7 No. 1 (January 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.59467

Abstract

Earthquake-induced liquefaction has been a complex and challenging topic in the field of geotechnical engineering due to its ability to cause catastrophic damage to the surrounding area. The manifestation of earthquake-induced liquefaction as observed from the effect of its past occurrence is damages on the ground and structures such as buildings, earth structures, and important lifelines structures. Liquefaction is caused by the loss of strength and stiffness of the cohesionless saturated soils due to the rapid dynamic loads from the earthquake. However, its complexity and uncertainty make the problems as one of the challenging problems in geotechnical engineering. One of the method to analyse the phenomena is through Physical modelling. Model subjected to the geotechnical centrifuge is required to analyse and observed the earthquake-induced liquefaction phenomena and this study aimed to understand the liquefaction phenomena, mechanism, and consequences through physical modelling by centrifuge and laboratory tests. This involved the physical modelling of the embankment which lies on a liquefiable foundation ground and subjection to earthquake motion of the 2011 Tohoku Earthquake retrieved from K-Net Mito stations. Moreover, geotechnical centrifuge test with 50 g of centrifugal acceleration was conducted to create the conditions of the actual field and the behaviour of the model related to acceleration, pore pressure, and displacement was observed using sensors. The liquefaction manifestation was observed in the model with the occurrence of lateral spreading, remnants of the sand boils, and deformation of the embankment. Furthermore, excess pore water pressure was rapidly developed and the pore pressure ratio (ru) higher than 1 was found to have indicated the occurrence of liquefaction while the embankment settle was estimated at 0.43 m.
The Utilization of Bacillus Subtilis Bacteria to Improve the Mechanical Properties of Concrete Sudipto Nath Priyom; Md. Moinul Islam; Wahhida Shumi
Journal of the Civil Engineering Forum Vol. 7 No. 1 (January 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.60216

Abstract

The utilization of concrete as a building material is well-known worldwide and increasing continuously due to its sustainability, low maintenance cost, durability, performance, etc. The ingredients of concrete, its constructional methodology, and exposure conditions have been observed to be moderating and improving daily but the focus of this research is on the laboratory investigation of Bacterial Concrete which is the technology established on the application of the mineral producing microbes like Bacillus subtilis which have the properties of bio-calcification and the ability to precipitate CaCO3 effectively inside concrete structures. This CaCO3 precipitation is able to fill the pores and cracks internally and this subsequently makes the structure to become more compact. Nutrient Broth (NB) media was employed for the growth and spore formation of Bacillus subtilis bacteria in this experimental study and four different bacterial culture densities including 0.107, 0.2, 0.637, and 1.221 were estimated at OD600 and directly added to the concrete matrix using the previously fixed water to culture ratio of 0.5:0.5. Moreover, 100 mm cubical concrete specimens were cast, subjected to compressive and tensile strength tests for different curing ages, and finally compared with Conventional Concrete with OD600=0. A significant increase was observed in the mechanical strengths due to the addition of Bacillus subtilis bacteria in concretes with a culture density of 0.637. Furthermore, cylindrical concrete specimens with 100 mm diameter and 200 mm height were prepared for Ultrasonic Pulse Velocity (UPV) analysis and the results showed specimens prepared with culture density of 0.637 have higher pulse velocity than other microbial groups. A UPV vs. compressive strength relationship curve was, however, later proposed for different strengths of concrete.
Regional Frequency Analysis of Rainfall, using L-Moment Method, as A Design Rainfall Prediction Devita Mayasari; Pratiwi Setyaning Putri
Journal of the Civil Engineering Forum Vol. 7 No. 2 (May 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.60498

Abstract

Frequency analysis is a method for predicting the probability of future hydrological events, based on historical data. Generally, frequency analysis of rainfall data and discharge data is performed using the moment method, but this method has a large bias, variant, and slope, thus there is a possibility of producing inaccurate hydrological design magnitudes. Meanwhile, the L-moment method is a linear combination of Probability Weighted Moment, with the ability to process data concisely and linearly. This study was therefore conducted to discover the L-moment method’s capacity to obtain a regional probability distribution and design rainfall, used as a basis for calculating hydrological planning, in anticipation of disasters. The study location, Mount Merapi, was selected to enable a more accurate prediction of maximum rainfall with the capacity to cause cold lava in the area, and consequently, reduce the risk of loss for people living within close proximity. According to the results, the L-moment regional ratio results were τ2R = 0.203, τ3R = 0.166, and τ4R = 0.169. The homogeneity and heterogeneity tests show all rainfall stations are uniform or homogeneous, and no data were released from the discordance test results. Also, the growth factor value increases in each return period design rainfall prediction. In this study, the suitable regional probability distribution for the research area is the Generalized Logistic distribution with formulated design rainfall equation. Regional design rainfall is able to predict possible rainfall within the area. The Test model showed the minimum RBias = 0.45%, maximum RBias = 41.583%, minimum RRSME = 0.45%, and maximum RRSME = 71.01%. Meanwhile, the L-moment method’s stability was shown by the model test minimum error = 1.64% and maximum error = 16.60%. The higher error value in the higher return period shows L-moment is able to reduce bias data, however, this has limitations in the higher return period.
Acceptance Analysis of PDAM Sleman’s Water Tariff, Based on Revenue and Willingness to Pay Projection Made Widiadnyana Wardiha; Istiarto Istiarto; Fatchan Nurrochmad
Journal of the Civil Engineering Forum Vol. 7 No. 2 (May 2021)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, UGM

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.60536

Abstract

In Sleman, the Regional Water Company (PDAM) provides clean water to the community and charges a tariff for each cubic meter of water sold to customers. According to the Minister of Home Affairs Regulation No. 71 of 2016 states, PDAM tariffs requiring an annual review in November. The most recent tariff was set by PDAM Sleman in 2016, therefore, a recalculation is required. In addition, there is a need to analyze the tariff acceptance from the service provider, and service recipient’s point of view. In this study, the calculation tariff method utilized a formula based on the Minister of Home Affairs Regulation No. 71 of 2016. Meanwhile, the acceptance analysis from profit point of view conducted by calculating the projection of water sales revenue, profit to earning assets ratio, and customer willingness to pay (WTP). Furthermore, revenue projections were obtained by multiplying tariffs with the water sold volume, while the WTP projection is obtained using the inflation method, based on the PDAM Sleman customers’ wTP, from the 2007’s research. PDAM Sleman tariffs based on calculations resulted in low tariffs of IDR3727.48, basic tariffs of IDR4659.36, and full rate of IDR9460.17. Based on the WTP analysis, the tariffs are feasible from the service recipient’s (PDAM customers) point of view, because this is affordable by customers, for the average water consumption. However, from the service provider’s (PDAM Sleman) point of view, the tariffs are not feasible a 0.31% profit ratio is much lower, compared to the 10% profit ratio. Therefore, tariff adjustments are required to increase profits. These strategies include determining tariffs based on consumption blocks alone, without breaking down based on customer group categories and adjusting the second and third consumption blocks’ rate.

Page 21 of 23 | Total Record : 225

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