Volume 10, Issue 4, August 2019

A Study on Free Vibration Under The Effect of Soil-Fluid-Structure Interaction on Concrete Gravity Dam

Iarly Vanderlei da Silveira, Lineu José Pedroso

University of Brasilia

Abstract- The knowledge of the behavior of dams under dynamic actions is a primordial factor in the safety of these structures. The analysis of the coupled dam-reservoir-foundation system is a complex problem due to the interaction between the water in the reservoir, the soil in the foundation and the dam concrete. Some research on this field considered only the fluid-structure interaction as an important factor in the dynamic response; however, recent research also shows the significant impact of the foundation on the dynamic behavior of the dams. This work aims to evidence the influence of the foundation and reservoir on the dynamic behavior of concrete gravity dams as a function of their parameters in terms of natural frequencies and mode of vibration. The dam-reservoir-foundation interaction will be investigated through the modal analysis by the finite element method via the ANSYS APDL software. For this study, the Pine Flat dam, USA, will be modeled in the ANSYS, and for the validation of the problem with literature, simulations on the dam was analyzed for four different cases: (1) Dam with rigid foundation and empty reservoir; (2) Dam with rigid foundation and full reservoir; (3) Dam with flexible foundation and empty reservoir and (4) Dam with flexible foundation and full reservoir. It is analyzed the first three modes for the structure with rigid and flexible foundation decoupled, as well as the reservoir and coupled modes for the rigid and flexible structure with the reservoir. It is possible to observe the influence of the reservoir and the foundation on the natural frequencies and modes of the coupled system, an aspect that highlights the importance of the integrated dam-reservoir-foundation analysis in concrete gravity dam projects...

Keywords- Interaction of Dam-Reservoir-Foundation, Dynamic Analysis, Foundation Flexibility and ANSYS

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Freedom of Expression in the Social Media in Indonesia

Ellectrananda Anugerah Ash-shidiqqi, SH, MH

Researcher of EAA Institute Indonesia

Abstract- This study discussed the regulation of freedom of expression on social media according to Indonesian law after the enactment of Law number 19 of 2016 concerning amendments to Law 11 of 2008 concerning Information and Electronic Transactions. Law number 19 of 2016 concerning amendments to Law 11 of 2008 concerning Information and Electronic Transactions is considered to threaten freedom of expression in Indonesia. Law number 19 of 2016 concerning amendments to Law 11 of 2008 concerning Electronic Information and Transactions limits the space for public opinion by interfering in civil rights which is a basic human right to argue that the function of the law is to provide criteria for an opinion which can be said to contain the element of insulting or defaming someone and include provisions regarding the limits of the implementation of the right to express opinions held by a person as well as obligations or sanctions therein in order to guarantee and provide protection for human rights both individually and in certain communities.

Keywords- Freedom of Expression, Constitution, Right and Social Media

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Behavioral Assessment of Cellular Concrete with Regard to the Process of Reinforcement Corrosion

Carlos Gomes Nascimento, Alexandre Filho, Thaís Marques, Eliana Monteiro, Paulo Helene

Department of Civil Engineering, University of Pernambuco, Madalena, Recife, Brasil
Department of Civil Engineering, University of Catholic of Pernambuco, Boa Vista, Recife, Brasil
Department of Civil Engineering, University of São Paulo, Ouro Preto, São Paulo, Brasil

Abstract- Concrete, a construction material used widely throughout the world, has undergone many advances over time, allowing for the production of special types of concrete to meet the many needs of society. One example is that of light concrete, made either with lightweight aggregates or through the inclusion of air pockets. Light concrete with embedded air, however, raises concerns about its behavior with regard to the corrosion process. Does the air present in the concrete, intentionally incorporated, have the capability of containing the corrosion products from the reinforcement, making the process asymptomatic and potentially more dangerous? The objective of this study was to verify the behavior of concrete of different light densities (L1, L2, and L3), when undergoing corrosion. Characterization tests showed that the compressive strength decreased as the embedded air content increased. Families L2 and L3 (higher air content) were more susceptible to reinforced steel corrosion, showing a greater intensity of corrosion, both visually as well as in the amount of steel mass lost. The behavior of some samples indicated the possibility that the process may be asymptomatic. With regard to cracking, higher levels of steel mass loss may lead to its occurrence even in light concretes.

Keywords- Concrete, Corrosion and Light

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