Journal of the Civil Engineering Forum
JCEF focuses on advancing the development of sustainable infrastructure and disseminating conceptual ideas and implementing countermeasures, particularly in the tropics, which are vulnerable to disasters. Specifically, we look to publish articles with the potential to make real-world contributions to improving both local communities and countries readiness for and responsiveness to natural and human-made disasters. The particular emphasis of JCEF is given to the civil & environmental engineering researches associated with natural disasters such as geo-disaster (earthquake, landslide, and volcanic eruption), water-related disaster (flood, debris flow, coastal disaster, and tsunami), and human-made disasters such as soil, water, and air pollution and water scarcity. Articles describing the topics of disaster risk reduction techniques, disaster early warning system, climate change adaptation, vulnerability analysis and trends, pre and/or post-disaster reconstruction and rehabilitation planning and management, forensic engineering, the socio-engineering approach for the countermeasures, or water reuse and recycle are particularly encouraged.
Articles
130 Documents
Pore Pressure Responses of Liquefied Numerical Sand Columns
Widjojo Prakoso;
Dheya Mazaya;
Rumaisha A. Kartika
Journal of the Civil Engineering Forum Vol. 8 No. 3 (September 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3395
The Palu 28 September 2021 M 7.5 Earthquake has brought several new challenges to the understanding of liquefaction and its following geotechnical phenomena. In addition, that main shock was followed by a series of aftershocks within a short time frame. The common geotechnical conditions of Palu area include layered soils conditions, and the associated variability of geotechnical conditions exists. This paper reports the dynamic effective stress analysis (ESA) study of four different liquefiable layered sand columns, and the above three conditions (layered soils, variability, aftershocks) are explicitly modeled. The dynamic ESA employs the PM4Sand constitutive model for liquefiable sands, implemented in the OpenSees platform. Three ground motion sets (“main shock only”, “main shock plus aftershock”, “aftershock” only) of variable amplitude, single frequency harmonic motions are used. The models are validated by comparing qualitatively their results against laboratory test results and field measurements. The saturated sand layers in all cases subjected to “main shock only” are liquefied with different detailed excess pore pressure (EPP) responses, highlighting the importance of the system response of liquefying sand columns. The cases subjected to “main shock plus aftershock” show a much a longer higher EPP state, while cases subjected to both “main shock plus aftershock” and “aftershock only” indicate a longer liquefaction state during the aftershock. The implication of the longer duration in the higher EPP state and the longer liquefaction state is that a longer duration of lower shear strength conditions would exist. The different EPP responses resulted from different geotechnical conditions represented by the four sand columns suggest that the variability of geotechnical conditions would have an important influence on the system response.
Evaluating Properties of Blended and High Volume Fly Ash Bottom Ash (FABA) Concrete in Peat Water
Monita Olivia Olivia;
Alfian Kamaldi;
Ismeddiyanto;
Gunawan Wibisono;
Edy Saputra
Journal of the Civil Engineering Forum Vol. 9 No. 1 (January 2023)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3397
FABA is a by-product of coal combustion in power plants comprising fly ash (FA) and bottom ash (BA) in ratios of 80/20. Fly ash has great potential as a mineral ingredient in concrete, while bottom ash compromises its strength and durability. However, both materials are used to improve the strength and durability of structures in sulfate, chloride, and acidic environments. This research evaluated the properties of blended and high-volume FABA concrete, such as the strength, porosity, weight loss, and sorptivity in organic acidic peat water. OPC (Ordinary Portland Cement) was compared to the blended concrete containing 25% FABA and its high-volume containing 50% and 75% FABA with target strengths of 15, 21, and 29 MPa. The compressive strength of blended and high volume FABA increased during the immersion period, while the porosity and sorptivity rates decreased. Furthermore, the strength of the OPC concrete declined at 28 days, with a gradual marginal weight loss of 5% observed in all mixes. This research suggested that blended and high-volume FABA has potential as a construction material in an acidic peatland environment.
Increasing Inventory Rating Factor of Steel Truss Bridge Through Orthotropic Steel Deck Panel Application
Erik Wahyu Pradana;
Andreas Triwiyono;
Ali Awaludin;
Saroj Mandal
Journal of the Civil Engineering Forum Vol. 8 No. 3 (September 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3416
Currently, 18,648 bridges with a total length of 510,366 km have been constructed in Indonesia, but only 86% are in good condition, while the rest are damaged. Steel truss bridge damage generally occurs on the RC decks, and its repair is often implemented through deck replacement or redecking using Orthotropic Steel Deck (OSD) panel. In Indonesia, this method has only been applied limitedly at the Citarum I Bridge in 2009 and the Cisadane Bridge in 2013, while the effect on the existing steel truss bridge is unknown. Therefore, this study aims to evaluate the steel truss bridge performance after OSD panel redecking through numerical modeling. The design process of the OSD panel was carried out by micro-modeling on ABAQUS CAE using shell elements with a mesh size of 50x50 mm and pinned boundary conditions. In this stage, the materials were assumed to be elastic with small deformations. The evaluation of steel truss bridge performance was performed on the A-class steel truss bridge Bina Marga design standard with a 60 m span by comparing the existing bridge inventory rating factor (using RC decks) to OSD panel redecking, which is an indicator of bridge self-weight reduction. Based on the structural macro-model developed using SAP2000, the bridge self-weight reduced the axial tension and compression forces on the steel truss bridge mainframe by 20.6%-24.6% and 20.5%-24.5%, respectively. Consequently, this increased the inventory rating factor by 9.3%-9.5%. In other words, using the OSD panels lighter than the existing RC decks increases the steel truss bridge capacity to resist the live load or vehicle rating throughout its service life.
The Performance of Ca(OH)2 to Reduce the Plasticity Index and Increase the Shear Strength Parameter for Expansive Soil
Mila Kusuma Wardani;
Putu Tantri K. Sari;
Mafrita Refionasari
Journal of the Civil Engineering Forum Vol. 8 No. 3 (September 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3455
The design on expansive soils can easily change in volume due to the influence of water content. This makes it necessary to consider soil improvement methods in the planning process to maintain the variation in the water content. One of these methods includes chemical stabilization, which is carried out by adding materials such as cement or lime. In expansive soils, stabilization efforts aim to reduce the plasticity index and increase the shear strength parameters. Therefore, this study focused on the addition of slaked lime (Ca(OH)2) to expansive soil in Lakarsantri, Surabaya. The stabilizing materials used contain calcium to form pozzolan in the clay and increase the bearing capacity parameter, which is variation in shear strength. The soil was taken at 2 points A and B with a different moisture content of 48.57% and 35.12%, as well as a high plasticity index value > 50% using a percentage (Ca(OH)2) of 6%-24% at a certain curing time. Based on the results, the plasticity index in the soil changed from very high to moderate with an optimum percentage value of 6% at 30 days of curing time. The optimum value of soil shear strength is (Ca(OH)2) 6% at 30 days of age in soil A, the cohesion value is 0.02 kg/cm2, and an internal shear angle of 36°. In soil B, the optimum shear strength obtained (Ca(OH)2) was 6% at the age of 10 days with a cohesion value of 0.14 kg/cm2 and an internal shear angle of 23.80°. Therefore, the results of this study show that the parameter of shear strength of the soil from the cohesion value showed that the cohesion value decreased with the addition of Ca(OH)2, while the internal shear angle increased.
SPT and CPT Correlation of Expansive Clay in Cikarang, Indonesia
Eddy Triyanto Sudjatmiko
Journal of the Civil Engineering Forum Vol. 8 No. 3 (September 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3458
Several CPT-SPT correlations have been reported worldwide to allow for the estimate of soil physical properties from one set of accessible data to another. Although most correlations are for silty and sandy soils, there is insufficient information on whether these correlations correspond to the silty clay soil conditions in Indonesia. Therefore, this study aims is to validate and enhance the generalized CPT-SPT correlation, with emphasis on Indonesian soil conditions to increase its prediction accuracy. The soil under examination is silty clay layers that cover most of Northern parts of West Java – Indonesia. Known with its expansive clay characteristics, these type of soils are sensitive to volume change as a result of seasonal variations in water content. For this study, data is collected from 8 (eight) locations in Cikarang Area. Each location consists of dedicated SPT and CPT pairs tests at 2 (two) m distance between each other. After analyzed with various statistical regression analysis of data relevant to this type of soil, a simple linear empirical CPT-SPT correlation with a fairly high correlation has been established allowing test findings to be translated and predicted for the relevant soils type. The simple CPT and SPT correlation is in form of n = qc/NSPT = 0.225 (Mpa), with data distribution of n ranges from 0.15 (Mpa) to 0.33 (Mpa). This results shows much lower n values compared to various correlation have been published worldwide. With respect to the clay soil formation, the low of n-value also reflect a lower density and cohesion bonding clay properties.
Compressive Strength Characteristics of Trass Stabilized Dredged Soil
Komang Arya Utama;
Tri Harianto;
Achmad Bakri Muhiddin;
Ardy Arsyad
Journal of the Civil Engineering Forum Vol. 8 No. 3 (September 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3463
Landslides from Mount Bawakaraeng caldera in 2004 has caused high dam sedimentation at the lower reaches of the Jeneberang River. The availability of this large sedimentary material makes this material need to be considered as an alternative to new materials in the geotechnical field. However, the results of laboratory tests applied to sedimentary materials show that the mechanical characteristics of these materials are not sufficient for construction materials. Therefore, it is very important to conduct a study on how to improve the quality of dredged soil by adding Trass as stabilizing agent to improve the quality of the mechanical properties of the dredged soil. This study aims to analyze the mechanical characteristics of the dredged soil stabilized with Trass. The research was conducted by adding Trass with composition 3%; 6%; 9% and 12%; respectively to the dry weight of the dredged soil. The curing time was applied for a period of 3, 7 and 14 days to analyze the significant binding of Trass to the stabilized dredged soil. Laboratory tests was conducted to the density test and unconfined compression test. The results showed that there was an increase in the maximum dry density of the dredged soil between 1.41% - 3.56% due to the addition of trass, and a decrease in the optimum water content between 0.8% - 2.7%. In addition, there was an increase in the value of free compressive strength from 47.76% to 388.89% in the trass stabilized dredged soil during the curing period of 3, 7 and 14 days. The use of dredged soil and trass as stabilizing agent can be an alternative option in soil improvement efforts based on the utilization of waste material and local content potential.
The Determination of Downhole Dynamic Compaction Paramaters Based on Finite Element Analysis
Martin Wijaya;
Ahmad Kemal Arsyad;
Aswin Lim;
Paulus Pramono Rahardjo
Journal of the Civil Engineering Forum Vol. 8 No. 3 (September 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3467
Downhole dynamic compaction (DDC) has been commonly used in China to stabilize collapsible soil through the application of construction and demolition waste material (CDW). DDC basically forms a column inside the soil stratum which is similar to a stone column except DDC materials are put in sequence and then compacted by using DDC hammer. Due to its attractive features such as its big diameter, feasibility of using oversized material particles, rapid and simple construction technique, it is used as one of the ground improvement methods for an airport project in Indonesia. Despite of all the advantages provided by DDC, it is difficult to obtain DDC parameters from laboratory tests as it is difficult to replicate the compaction effort induced by the DDC hammer and laboratory tests are not commonly employed for oversized materials. Hence, alternative method is required to evaluate DDC parameters. In this study, static load test is conducted to determine load-deformation curve of the DDC pile. Soil parameters are first determined through soil test data such as standard penetration test (SPT), laboratory test and also pressure meter tests. Correlation between pressure meter tests and SPT test result is also carried in order to interpret the soil parameter at the site. Axisymmetric finite element analysis is then carried by using MIDAS GTS NX in order to back analyses DDC parameters by matching the simulation curve with load settlement curve of the DDC. In this paper, it is shown that back analysis using hardening soil model for DDC material can be used to match simulation curve with the load-deformation curve.
Strength Performance of Concrete Using Rice Husk Ash (RHA) as Supplementary Cementitious Material (SCM)
Dahlia Patah;
Amry Dasar
Journal of the Civil Engineering Forum Vol. 8 No. 3 (September 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3488
Rice husk ash (RHA) is an industrial waste obtained from raw material that is processed into ash through the combustion process. It is a solid waste in fine powder form, which contains a large amount of silica and can promote RHA through combustion under certain conditions. Furthermore, it has a high pozzolanic activity due to a large amount of silica, which is a kind of supplementary cementitious material (SCM). According to ASTM C618, RHA has potential as sustainable material that meets the specification of the chemical configuration of pozzolan compound that can be used in cement products and concrete mixing. The use of RHA as SCMs in concrete construction contributes to sustainability and eco-material. Therefore, this study aims to evaluate the application of RHA as SCM on the strength base performance of concrete. The sample was directly collected from the rice field after the natural combusting process without additional treatment, controlled burning temperature, or time. RHA was used as an admixture for cement substitute and the mechanical characteristics were evaluated using a cylindrical concrete specimen made with 100-mm diameter and 200-mm height. After 24-hours, the concrete specimens were demolded and immediately immersed curing in fresh water with uncontrolled laboratory condition until the day of testing. The results showed that RHA with a replacement ratio of 7.5% obtained an optimum compressive strength of 40.65 MPa and 48.79 MPa at 28 and 91 days, respectively. The split tensile test also gave an optimum replacement ratio of RHA is 10% with 4.57 MPa at 28 days. These results provide good input on using RHA as SCM for concrete strength base performance and future sustainable material.
Comparison of Material Point Method and Finite Element Method for Post-Failure Large Deformation Geotechnical Analysis
Arif Yunando Sunanhadikusuma;
Ezra Yoanes Setiasabda Tjung;
Aswin Lim
Journal of the Civil Engineering Forum Vol. 9 No. 1 (January 2023)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3524
Finite Element Method (FEM) has been the state-of-the-art method in geotechnical analysis since it first formulated in the 40s. It capable to handle Multiphysics simulation, soil-structure and soil-water interaction, and time history analysis. Though powerful, the standard Lagrangian FEM suffers mesh distortion when handling large strain deformation problem. This mesh entanglement problem makes post-failure analysis is considerably challenging to model if not impossible to do using FEM. The Material Point Method (MPM) then later introduced to solve these large strain deformation problems. Adapted from the Particle in Cell (PIC) method, MPM is a hybrid method that combines Eularian and Lagrangian approach by utilizing moving material points which are moving over spatially fixed computational mesh. This approach enables MPM to calculate not only fluid mechanics such in PIC but also solid mechanics and its intermediatory states. To demonstrate the capability of MPM and its consistency with FEM in geotechnical analysis, this article presents a comparison of FEM and MPM analysis on a hypothetical slope using Mohr-Coulomb constitutive model. The simulation shows that both FEM and MPM analyses are consistent to each other especially in small strain scheme. However, in large strain deformation, MPM is still able to get convergent result while FEM is not. The MPM simulation is also able to animate post failure behavior clearly, calculate post-failure strains and stresses distribution, and present final geometry of the model.
The Effect of Diatomaceous Earth Addition on CBR Values of Glee Geunteng Soil in Aceh Besar, Aceh Province, Indonesia
Banta Chairullah;
Munira Sungkar;
Muhammad Ghiffari Ritonga
Journal of the Civil Engineering Forum Vol. 9 No. 1 (January 2023)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada
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DOI: 10.22146/jcef.3529
The soil which is the platform often used for construction activities needs the strength to resist loads. However, its physical and mechanical properties are sometimes naturally limited and this implies there is a need for improvement and stabilization. Therefore, this study uses diatomaceous earth, which is a natural pozzolanic material classified as a type of Supplementary Cementing Materials (SCM), as an additive. The chemical stabilization was conducted by mixing the soil with stabilizing materials such as cement, lime, fly ash or others that have the ability to change the chemical composition and combination of soil. It is important to note that diatomaceous earth has similar properties as other pozzolanic materials such as fly ash and metakaolin powder and this is the reason it is expected to function as a soil stabilizing agent needed to improve soil properties. This study was conducted using the soil from Glee Geunteng in Peukan Bada as well as the diatomaceous earth obtained from Lambeureunut Village, Aceh Besar Regency, Aceh Province, Indonesia. The main purpose was to determine the California Bearing Ratio (CBR) value of the Glee Geunteng soil mixed with diatomaceous earth at 5, 10, 15, and 20% dry weight of the soil. The CBR test consisted of unsoaked CBR, soaked CBR testing at 4 days, and swelling properties of CBR with a variety of diatomaceous earth mixtures. Glee Geunteng soil was classified as A-6 Group Index 3 based on the AASHTO soil classification and as the SC (silty clay) soil according to the USCS classification. The results showed that the unsoaked CBR value reduced from 35.96% for the natural Glee Geunteng soil to 31.65% for the soil mixed with 20% diatomaceous earth material. A similar trend was observed for the soaked CBR value with a reduction from 15.57% to 6.98%. The decrease in CBR value was perceived to be caused by the very small silica content (SiO2 ) in diatomaceous earth material with 42.09% compared to the 86% in the material obtained from another source in the previous research by Hidayati.