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15.15: Dynamic Analysis of Steel-Concrete Composite Building Floors Subjected to Human Rhythmic Activities

ce/papers 2017年第2-3期1卷

作者： Fernanda Fernandes Campista José Guilherme Santos da Silva Civil Engineering Post-graduate Programme PGECIV State University of Rio de Janeiro UERJ Brazil

This work aims is to investigate the structural dynamic response of steel-concrete composite floors, when subjected to rhythmic human activities, based on experimental tests and numerical modelling, from the point of view of human comfort. The main focus of this paper is to study the effect of the dynamic interaction between the occupants and the floors, representing these people by SDOF biodynamic models (mass-spring-damper systems), in order to better evaluate the dynamic response and the vibration serviceability states. This way, the investigated structural model is related to a steel-concrete composite building which is composed of three floors used for aerobics classes, with dimensions of 20m × 20m, a total area of 1200m 2 (3 × 400m 2 ) and a ceiling height of 4m. The numerical modelling of the structure was performed by ANSYS program and was based on the finite element method (FEM). In order to evaluate the dynamic response of the investigated steel-concrete composite building, accelerations associated with 32 individuals practicing rhythmic activities were experimentally obtained to introduce them into the finite element model. Thus, the dynamic response of the building floors was evaluated in terms of the peak accelerations, RMS and VDV values, according to human comfort criteria and considering situations of the design practice.

关键词： steel-concrete composite floors vibration analysis rhythmic activities human comfort

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Assessing the Performance of Eggshell Ash as a Sustainable Bitumen Modifier

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SSRN 2023年

作者： Syammaun, Tamalkhani Husaini, Husaini Abdullah, Abdullah Isya, Muhammad Rachman, Firmansyah Doctoral Program School of Engineering Post Graduate Program Universitas Syiah Kuala Banda Aceh23111 Indonesia Department of Civil Engineering Universitas Muhammadiyah Aceh Banda Aceh23123 Indonesia Department of Mechanical Engineering Universitas Syiah Kuala Banda Aceh23111 Indonesia Department of Civil Engineering Universitas Syiah Kuala Banda Aceh23111 Indonesia

The disposal of eggshells in landfills presents an ongoing global environmental issue that demands immediate attention. However, a promising solution lies in utilizing eggshells as modifiers in bitumen binders, offering a sustainable approach to alleviating this burden. This study focuses on crushing eggshells to produce eggshell ash, which is then explored as a potential modifier in bitumen binders. The objective is to evaluate the properties of modified bitumen binders incorporating eggshell waste sourced from the food industry and examine their application in bitumen engineering. Employing a 60/70 penetration-grade asphalt binder as the research foundation, the optimal weight percentage of eggshell ash in the bitumen is determined, considering four levels (5%, 7%, 10%, and 12%) and two different heating temperatures (100°C and 200°C). Several tests are conducted to comprehensively evaluate the eggshell ash, including SEM-EDS and FTIR analyses, providing valuable technical insights into its properties. Additionally, dynamic shear rheometer (DSR) measurements are employed to analyze the characteristics of the bitumen incorporating eggshell ash. The primary oxide group present in the eggshell ash is calcium carbonate (CaCO3). Notably, higher concentrations of eggshell ash enhance the resistance of bitumen binders to high temperatures, as indicated by the penetration index results. Furthermore, DSR testing reveals that the addition of eggshell ash significantly increases the rigidity of the bitumen binders, resulting in improved resistance to deformation. © 2023, The Authors. All rights reserved.

关键词： Binders

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15.16: Vibration Analysis and Human Comfort Investigation of a Steel-Concrete Composite Building under Nondeterministic Wind Loadings

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ce/papers 2017年第2-3期1卷

作者： José Guilherme Santos da Silva Rafael Rangel Barboza Civil Engineering Post-graduate Programme PGECIV State University of Rio de Janeiro UERJ Brazil

Based on a favourable economic scenario combined with a significative technological advance in science materials and also construction processes, it must be emphasized that the Brazilian cities have shown substantial growth, regarding the construction of tall and slender buildings. This architectural trend has conducted the design of these buildings to solutions composed by very flexible structural systems, resulting in slender buildings with very low natural frequencies values and therefore more susceptible to problems of excessive vibrations, undesirable crack openings and even discomfort to the occupants. This way, having in mind the slenderness levels presented more recently, these buildings need to have their structural dynamic behaviour investigated, in order to ensure the human comfort. Thus, this research work aims to investigate the dynamic structural behaviour and also evaluates the human comfort of tall buildings, when subjected to the non-deterministic action of the wind. This way, the structural behaviour of a forty eight-storey steel-concrete composite building with 172.8m high subjected to the nondeterministic wind dynamic actions is investigated. The results obtained along the numerical analysis, in terms of the displacements and accelerations values, in time and frequency domain, are compared with the limits proposed by technical guides and design recommendations, aiming to evaluate the human comfort levels of the analysed building, regarding to the situations of the design practice.

关键词： tall buildings dynamic behaviour human comfort nondeterministic wind actions

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12.15: Structural performance of stainless lap bolted joints

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ce/papers 2017年第2-3期1卷

作者： Raphael Freire Pedro Colmar Gonçalves da Silva Vellasco André Tenchini da Silva Luciano Rodrigues Ornelas de Lima PGECIV – Civil Engineering Post-Graduate Program State of Rio de Janeiro – UERJ Structural Engineering Department State University of Rio de Janeiro – UERJ

The stainless steel employed in the structural elements present high corrosion resistance, durability, fire resistance and high aesthetic value compared to those constructed using carbon steel. In contrast, the stainless steel structures design is made following the requirements based on the carbon steel analogies. In fact, the structural performance of stainless steel is complex and dissimilar where some stainless grades presenting nonlinear tension versus strain curves without a defined yield plateau and large strain hardening. These properties influence on structural performance of the lap bolted joints. The Eurocode 3 pt. 1.4, one of the most adopted design codes, recommends two structural design criteria for the stainless steel elements under tension: ultimate resistance of the net cross-section at holes or plastic resistance of the gross cross-section. The present work aimed to investigate the structural response of lap bolted joints made of three stainless steel grades: austenitic, ferritic and duplex. Nonlinear numerical analyses has been carried out using ABAQUS 6.14 program where the response have shown a good agreement in terms of the maximum loads and failure modes when compared to the performed experiments. The results indicated a conservative level of safety from Eurocode 3 pt. 1.4 code provisions in comparison to the experimental results.

关键词： stainless steel lap bolted joint experimental analysis numerical finite element simulations

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Influence of the Corrosion Degree of Hot-Dipped Galvanized Reinforcements on its Bond Strength to Concrete

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SSRN 2024年

作者： da Fonsêca, Márcia Suzanna Dutra Abreu Borges Meira, Gibson Rocha The Civil and Environmental Engineering of Federal University of Paraíba João Pessoa Brazil The Federal Institute of Education Science and Technology of Paraíba João Pessoa Brazil The Civil and Environmental Engineering Post-graduate Program of Federal University of Paraíba João Pessoa Brazil

This work studies the behavior of hot-dipped galvanized steel against chloride corrosion and its effect on its bond strength to concrete. Two steel diameters were adopted and bond strength was assessed using a standardized pull-out test, followed by measuring different degrees of corrosion. The results show that the initial corrosion of hot-dipped galvanized steel, due to the high alkalinity of fresh concrete, does not affect the structural performance of reinforced concrete and that galvanized steel has superior bond strength to concrete than non-galvanized steel for small corrosion rates. However, it decreases as the corrosion degree significantly increases. © 2024, The Authors. All rights reserved.

关键词： Reinforced concrete

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Design alternative on peat soil

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IOP Conference Series: Materials Science and engineering 2020年第1期1007卷

作者： Vicky Muroby Chaidir Anwar Makarim Civil Engineering Post-graduate Program Faculty of Engineering Universitas Tarumanagara

Construction on peat soil has its own difficulty and challenge due to its properties of low shear strength, high compressibility, high water content, and flammable material. Indonesia ranked 4th on peat land area around the world after Canada, Russia, and United States. Based on recent mapping, peat land covers 14,9 million hectare in Indonesia. This paper presents the finding from literature studies regarding peat soil, construction on peat soil, case studies for road infrastructure construction on peat soil at West Borneo, Indonesia, and provide analysis and recommendation for the problems faced. Construction on peat soil requires special attention, especially on the design and execution. In the event where construction must be performed on a peatland which thickness is < 3m, the approach recommended is peat removal and replacement. If the peat thickness is 3-10 m, adopt the preloading, construction with vertical and sand drain, lightweight fills, surface mattress, stone column, etc. If the peat thickness is < 10m, use pile as foundation. Unit price contract is preferable over lumpsum contract due to the high uncertainties of peat soil. Environment impact due to construction on peat soil need to be accounted for, also the risk of peat fires need to be considered if dewatering used.

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On the delay factors of the private construction projects in Medan city

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IOP Conference Series: Earth and Environmental Science 2018年第1期126卷

作者： A. Perwira Mulia Tarigan Subroto Teaching Staff Post Graduate Study Program of Civil Engineering Universitas Sumatera Utara Former Graduate Student Post Graduate Study Program of Civil Engineering Universitas Sumatera Utara

The delay in construction projects undertaken by contractors is impeding the economic growth of a region. Medan city which is one of the big cities in Indonesia is suffering from it. This study aims to identify the dominant factors causing delays in construction projects conducted by private contractors. The interview method with questionnaires is used to involve 20 contractors, 10 consultants, and 10 owner representatives in the study. From the 45 identified factors causing delays, the highest ranking is the change of work demand by the project owners with 71.84% importance index.

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Numerical analysis of the influence of the contact boundary condition and specimen geometry on concrete compressive strength

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Procedia Structural Integrity 2023年 47卷 261-267页

作者： Caroline Bremm Luísa Inda Leandro Ferreira Friedrich Sabrina Vantadori Ignacio Iturrioz Luis Kosteski Engineering Post Graduation Program Federal University of Pampa Av. Tiaraju 810 Alegrete 97546-550 Brazil Civil Engineering Graduate Program Federal University of Pampa Av. Tiaraju 810 Alegrete 97546-550 Brazil Program of Mechanical Pos-Graduation Federal University of Rio Grande do Sul Sarmento Leite 425 Porto Alegre 90040-060 Brazil Department of Engineering & Architecture University of Parma Parco Area delle Scienze 181/A 43124 Parma Italy

In the present paper, the influence of the contact boundary condition and specimen geometry on the concrete compressive strength is numerically investigated by using a version of the Lattice Discrete Element Method (LDEM), implemented on Abaqus/Explicit. More precisely, two types of contact boundary conditions are considered and, for each of them, three different slenderness levels (height/width ratio - h/b) are analyzed (that is, h/b = 0.5, 1.0, and 2.0) by considering a square cross-section. Moreover, for h/b = 2.0, a circular cross-section is also examined. Two models are developed: one by using the LDEM and the other by using a hybrid model, combining Finite Elements and LDEs. The results show that both the boundary conditions and the sample geometry influence the axial compressive strength.

关键词： Abaqus concrete compressive strength Lattice Discrete Element Method (LDEM)

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Flood Susceptibility Mapping using GIS Based on Fuzzy AHP Method in Keureuto River Basin, Aceh

Flood Susceptibility Mapping using GIS Based on Fuzzy AHP Me...

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Science and Information Technology in Smart Administration (ICSINTESA), International Conference of

作者： Maimun Rizalihadi Alfiansyah Yulianur Yuwaldi Away Ella Meilianda Doctoral Program. Post Graduate. Program. Syiah Kuala University Banda Aceh Indonesia Civil Engineering Department Syiah Kuala University Banda Aceh Indonesia Elect. and Compt. Eng. Department Syiah Kuala University Banda Aceh Indonesia

ISBN: (数字)9798350376111

ISBN: (纸本)9798350376128

Flood susceptibility mapping become crucial for describing flood risk zones and development mitigation actions. By means of a multi-criteria decision analysis-Analytical Hierarchy Process (MCDA-AHP), this study examined flood-inundation of Keureuto watershed in North Aceh. The study employed a mixture of AHP and GIS (Geographic Information System) on a fuzzy environment, and tested with the field observation by mean of AUC-ROC method to see its accuracy. Eleven key criteria that can trigger floods were chosen: rainfall, flow accumulation, river density, distance to the river, elevation, slope, TWI, LULC, soil type, NDVI, and curvature. The significance of all of criteria was arranged based on the weights which is determined using Fuzzy-AHP (FAHP) pairwise comparison matrix (PCM). The highest flood-triggering criteria were rainfall (0.199), TWI (0.159), flow accumulation (0.143), distance to rivers (0.094), and slope (0.091). Based on fuzzy overlay, the area of $323.747 \mathrm{~km}^{2}\left(34.635 \%\right.$ of $934.745 \mathbf{k m}^{2}$ of total area) was high to very high flood susceptibility which is mostly concentrated in downstream of river basin, while the area of $610.998 \mathrm{~km}^{2}(65.365 \%$ of the total area) has moderate to very low flood susceptibility. where the model achieved a higher AUC value of $\mathbf{7 7. 8 9 \%}$, indicating better performance. It is proved that the FAHP model is very good for forecasting flood-inundation areas in the Keureuto River basin.

关键词： Phase change materials Rain Accuracy Prevention and mitigation Watersheds Soil Predictive models Rivers Floods Geographic information systems

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Flood handling with priority scale determination in Samarinda Seberang from East Kalimantan Province Indonesia

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IOP Conference Series: Materials Science and engineering 2020年第1期885卷

作者： SSN. Banjarsanti P. Kukuh Theta Margaritifera Civil Engineering Study Program Samarinda State Polytechnic Civil Engineering Post-graduate Program Gunadarma University Depok

Handling of flooding caused by changes in land use often causes changes and problems in the magnitude of runoff coefficient, discharge, water level, and drainage channel dimensions, as happened in Samarinda Seberang. The purpose of this study was to plan a drainage channel according to the priority scale using the Rational Modification Method as a Hydrological Analysis and Manning as a Hydraulics Analysis. Handling method is carried out in the form of structuring and planning the drainage system according to priority scale based on inundation parameters, economic studies, social and transportation disturbances, loss of housing areas, and property rights. The higher the criteria for handling the area is a priority. The results showed that the highest priority scale (610) was obtained on Cipto Mangunkusumo street, and the lowest priority scale (220) was at Bung Tomo street and Hasanuddin street. Cipto Mangunkusumo street as the highest priority scale will be planned for the first priority drainage channel with a design flood discharge in the 10 year return period (Q) 7.79 m3 / sec, the drainage channel dimension consists of the basic width of the channel (b) 0.77 m ∼ 0.80 m, channel peak width (T) 3.30 m, channel depth (h) 1.925 m, watch height (f) 0.6 m, total depth 2.52 m, and slope of channel wall (m) 1: 1).

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