Pouyan PressComputational Engineering and Physical Modeling2588-69594120210101Numerical Analysis of Segmental Tunnel Linings employing a Hybrid Modeling Approach11812204110.22115/cepm.2021.247314.1130ENAndreas-NizarGranitzerInstitute of Soil Mechanics, Foundation Engineering and Computational Geotechnics, Graz University of Technology, Austria0000-0002-5839-4300FranzTschuchniggInstitute of Soil Mechanics, Foundation Engineering and Computational Geotechnics, Graz University of Technology, Austria0000-0002-4279-7703Journal Article20200908The structural performance of shield-driven tunnel linings is considerably affected by the existence of segmental joints. Nevertheless, segmental tunnel linings are commonly modelled as isotropic structures in engineering practice, thereby ignoring the joint-induced stiffness reduction in numerical analysis. A more realistic approach is to consider the tunnel structure as continuous ring with adjusted rigidities which is also referred to as indirect-joint model. However, this modeling approach is a complicated task since it requires the definition of anisotropic stiffness parameters. In this context, the present paper introduces a hybrid modeling approach, which combines analytical solutions and numerical studies. Based on extensive numerical studies, anisotropic stiffness parameters are defined to model an existing drainage tunnel (SDT). Finally, a case study is discussed, where the developed indirect-joint model is used to investigate the structural response of the SDT. In this context, particular emphasis is placed on the deformation of the tunnel crown developing throughout the entire construction phase.http://www.jcepm.com/article_122041_76b2c6642e619b5bc5097fb3d2fffbf7.pdfPouyan PressComputational Engineering and Physical Modeling2588-69594120210101Comparative Three-Dimensional Finite Element Analysis of Piled Raft Foundations193611553210.22115/cepm.2020.234834.1111ENAlirezaAbdolrezayiGeotechnical Engineer, Department of Civil Engineering, University of Tehran, Tehran, Iran0000-0002-6325-9808NavidKhayatDepartment of Civil Engineering, Islamic Azad University, Ahvaz branch, Ahvaz, IranJournal Article202006113-dimensional finite element method as a general method to solve complex problems is one of the most powerful numerical methods which can be used for piled raft foundation analysis. These models can consider the complex interaction between soil and structure. Among available 3D FEM software for modelling pield raft foundations, in this paper MIDAS GTS is used due to its various element type and modeling abilities. In this article, different pile modeling techniques in MIDAS GTS software (like pile modeling by solid elements, modeling by beam elements connected to soil elements and modeling by EPM ) are compared with a real pile loading test data. Results showed that all three methods have excellent compatibility with the results of loading test in the linear area of the load-settlement curve, and SEM and EPM kept their conformity further in the non-linear area as well. One of the most critical problems in 3D FEM modeling process of piled raft foundations with SEM was an increase in the number of elements when the number of piles increases and that leads to model's slowness and convergence problem. Piles modeling by EPM needs much lower elements; using this method, skin friction resistance, tip resistance and displacement between pile and soil can be easily calibrated with a pile loading test data which facilitates piled raft analysis with a large number of piles. After comparing different pile modeling techniques through MIDAS GTS software, the ability of the software for modeling piled raft foundations had been verified; Results show acceptable agreement between software output and monitored values and also outputs from other methods and software.http://www.jcepm.com/article_115532_8c7394894fb24b8312b729b38198c234.pdfPouyan PressComputational Engineering and Physical Modeling2588-69594120210101Cost Analysis of a Large Solar Plant with Parabolic Trough Concentrators Using Molten Salt Storage Tank375512204310.22115/cepm.2021.240381.1120ENMohamed H.MohamedMechanical Power Dept., Faculty of Engineering, Mattaria, Helwan University, Cairo, EgyptCollege of Engineering and Islamic Architecture, Umm Al-Qura University, Makkah 5555, Saudi Arabia0000-0002-8609-150XAbd El-Nabi ZaghloulEl-SayedHigh Institute of Engineering, Elshorouk Academy, Cairo, EgyptKhairy F.MegallaMechanical Power Dept., Faculty of Engineering, Mattaria, Helwan University, Cairo, EgyptHassan F.ElattarDepartment of Mechanical Engineering, Benha Faculty of Engineering, Benha University, Benha, EgyptJournal Article20200720Thermal storage tank is a standout amongst the most encouraging methods in solar thermal power stations operation. Accurate selection of appropriate storage system is a significant parameter to ensure the continuous working of thermal solar station during the absence of the sun. This work describes financial analysis of different locations of a 500MW Solar Plant in Egypt and also thermal tank design. The selected three locations which are investigated in this study are Aswan, EL-Arish and Hurghada to build this challenged size solar station. These locations cover the tree levels of the solar intensity in Egypt. This study is achieved by System Advisor Model (SAM) as financial analysis simulation tool. All the solar thermal power plants are working twenty-four hours per day and with sixteen full load hours of thermal energy storage (TES). Parametric design and cost analysis for each location, comparison between these locations are introduced to select the optimum location for 500MW solar power plant. The results of this study is considered a good orientation for feasibility study for CPS (concentrators parabolic system) projects, and it is needed in all over the world in particular, in Egypt for future to produce clean energy.http://www.jcepm.com/article_122043_9807e2a9f33c331126347b668f8e0c77.pdfPouyan PressComputational Engineering and Physical Modeling2588-69594120210101Characteristic Properties of Concrete with Recycled Burnt Bricks as Coarse Aggregates Replacement567212204410.22115/cepm.2021.245270.1126ENSunday UgochukwuAzunnaCivil Works Department, Ringo Star Ventures Ltd, 34 Panama Street Ministers Hill, Maitama, Abuja, Nigeria0000000190374847Joseph O.OgarDepartment of Civil Engineering, Faculty of Engineering, Federal Polytechnic Bauchi, Bauchi, NigeriaJournal Article20200825To counter the depletion of river sand and to reduce the menace caused by disposal of crushed brick wastes, the use of crushed bricks to produce a more environmentally sustainable and economical concrete is explored. This project studied the properties of concrete made using crushed burnt bricks as an aggregate in comparison with concrete made using natural coarse aggregates. Experimental investigation was carried on the concrete in its wet and dry state to determine the durability and mechanical properties of the concrete by testing the workability, water absorption, density and compressive strength test of the concrete. The result of the water absorption test shows that concretes made using crushed burnt bricks as coarse aggregates absorbed more water with value of 7.83% than conventional concrete with value of 2.83% at 28 days curing. The strength test result carried out indicates that conventional concrete at 28 days has strength of 22.96 N/mm2 higher than that of concretes made using crushed burnt bricks at 28 days of curing with value of 15.45 N/mm2, however, the strength of concretes from crushed burnt bricks still lies within the acceptable limit. Other test carried out on the crushed burnt aggregates to ascertain their suitability were, Aggregates Impact Value test (AIV) with value at 15.68% and Aggregates Crushing Value test (ACV) with value at 23.36%. The properties and quality of the crushed burnt bricks aggregates were also determined.http://www.jcepm.com/article_122044_fe8732563e767bd4835ff83806e9c62c.pdfPouyan PressComputational Engineering and Physical Modeling2588-69594120210101The Relation between Deposited Weight and Quality of Coating in EPD Method Derived by Genetic Programming738311553310.22115/cepm.2020.239389.1117ENMohammad SadeghShakeriMaterials and Energy Research Center (MERC), P.O. Box 31779-83634, Karaj, IranJournal Article20200713In this work, the relation between deposited weight and the quality of electrophoretically deposited coating has been derived using genetic programming method. Although, the accumulated mass is thicken by time, its quality varies at different times of coating procedure. Three different suspensions i.e. Mullite, SiC and Mullite/SiC were stabled in ethanol medium and the suspended particles were electrophoretically deposited on C-C composite at several different times. The results of SEM micrographs show that the quality of coating rises by time and after some time it starts to drop for all three suspensions. The results of Zeta potential of suspension after different times of coating that is derived by pH measurement, illustrate the same pattern. There is a maximum for zeta potential after 150 sec of deposition process. Accordingly, the quality of coating rises as a result of enhancement of Zeta potential in suspensions. Last but not least, there is a relation between deposition time and quality of coating which is mathematically modeled using genetic programming method. In this case, the root of multiplication of Z-w and w-t differential equations could show the optimum time of deposition process.http://www.jcepm.com/article_115533_dec670a886f87b244c284efb3dc0efb4.pdfPouyan PressComputational Engineering and Physical Modeling2588-69594120210101Effect of Threshold Twin Volume Fraction in Crystal Plasticity Modeling8410012204210.22115/cepm.2021.245719.1128ENFaYongLiCollege of Materials Science and Engineering, Chongqing University, Chongqing, ChinaAdrienChapuisCollege of Materials Science and Engineering, Chongqing University, Chongqing, ChinaQingLiuCollege of Materials Science and Engineering, Chongqing University, Chongqing, ChinaJournal Article20200828Modeling of metals deforming by twinning requires reorienting the matrix into twin orientation. In twinning models like the Predominant Twin Reorientation scheme (PTR), a threshold volume fraction is defined with an empiric equation to reorient the parent grain into the dominant twin variant. This equation contains two parameters which are first investigated in the present study, showing their effect on simulated flow stress and twin volume fraction evolution. Magnesium, with a tension and a compression twinning modes, is taken as an example to compare the expected experimental behavior and the modeled behavior. Complex deformations such as strain path change and multiple twinning are modeled with the PTR, and simulated stress, twin volume fraction and texture are correlated with the expected behavior. The PTR shows a good agreement with experiments when the twin volume fraction corresponds to the fraction of grains reoriented into twins, but limited predictability when the twinned grains are not reoriented.http://www.jcepm.com/article_122042_0ee7bfd18008990111fe5f2e5890dbe1.pdf