Anagnostopoulos K.,Democritus University of Thrace |
Vavatsikos A.,Civil Engineer
Journal of Water Resources Planning and Management | Year: 2012
When decentralized strategies are considered for managing wastewater, natural systems for wastewater treatment (NSWT) (constructed wetlands) seem to be strongly preferred in comparison with the conventional activated sludge wastewater treatment systems. However, because of their high land requirements, land-use suitability analysis should be conducted to specify adequate areas for their accommodation. Multicriteria spatial decision support systems have emerged as the technology that takes into account both decision criteria and constraints in complex land-use planning problems. This study presents a multiattribute decision analysis approach called the spatial fuzzy Analytic Hierarchy Process (SFAHP) to support raster-based land-use suitability studies for the implementation of NSWT. The SFAHP enables decision makers to circumvent vagueness when they perform evaluations using linguistic variables. Its application in a region of Northeastern Greece using a two-level criteria hierarchical model demonstrates its potential use for suitability analyses. © 2012 American Society of Civil Engineers.
Porsani J.L.,University of Sao Paulo |
Ruy Y.B.,University of Sao Paulo |
Ramos F.P.,Civil Engineer |
Journal of Applied Geophysics | Year: 2012
The rapid industrial development and disorganized population growth in huge cities bring about various urban problems due to intense use of physical space on and below the surface. Subsurface problems in metropolitan areas are caused by subway line construction, which often follows the routes of utility networks, such as electric and telephone cables, water and gas pipes, storm sewers, etc. Usually, the main problems are related to damage or destruction of preexisting utilities, often putting human lives at risk. With the purpose of minimizing risks, GPR-profiling with 200. MHz antennae was done at two sites, both located in downtown São Paulo, Brazil. The objectives of this work were to map utilities or existing infrastructure in the subsurface in order to orient the construction of the Line 4 (yellow) subway tunnel in São Paulo. GPR profiles can detect water pipes, utility networks in the subsurface, and concrete foundation columns or pilings in subsoil up to 2. m depth. In addition, the GPR profiles also provided details of the target shapes in the subsurface. GPR interpretations combined with lithological information from boreholes and trenches opened in the study areas were extremely important in mapping of the correct spatial distribution of buried utilities at these two sites in São Paulo. This information improves and updates maps of utility placement, serves as a basis for planning of the geotechnical excavation of the Line 4 (yellow) subway tunnel in São Paulo, helps minimize problems related to destruction of preexisting utilities in the subsoil, and avoids risk of dangerous accidents. © 2012 Elsevier B.V..
Ersubasi F.,Civil Engineer |
Korkmaz H.H.,Selcuk University
Natural Hazards and Earth System Science | Year: 2010
Turkey and neighborhood countries like Greece and Iran are situated on an active earthquake region. Masonry type structures are very common on these countries, especially on the rural areas. During the last earthquakes, several masonry type houses were collapsed, causing loss of life and property. Strengthening methods of masonry houses were discussed in this study. The paper summarizes the results of a experimental programme carried out on models, scaled 1/10, of one-storey masonry buildings. First specimen tested was the reference specimen and used for comparison purposes. Other specimens contained several strengthening strategies. A total of 9 specimens were tested. The results allow to assess the efficiency of the various strengthening techniques employed. © Author(s) 2010.
Kloukinas P.,University of Patras |
Langousis M.,Civil Engineer |
Mylonakis G.,University of Patras
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2012
Design of retaining walls for earthquake action is traditionally performed by limit analysis procedures-notably the classical solution of Mononobe-Okabe and its variants. Fundamental assumptions of these methods are (1) the static nature of seismic excitation, (2) the compliance in sliding and/or rocking of the base of the wall, (3) the shear failure of the backfill and the soil-wall interface, and (4) the prespecified point of application of soil thrust. Given the restrictive nature of these assumptions, alternative solutions based on wave-propagation theory have been developed that do not require failure of the backfill and thereby are applicable to nonyielding walls. Because of the complex mathematics involved, the use of these solutions in practice appears to be limited. A special integration technique inspired from the seminal work of Vlasov and Leontiev is presented, which simplifies the analysis by providing closed-form solutions suitable for practical use. © 2012 American Society of Civil Engineers.
Foti D.,University of Bari |
Ivorra Chorro S.,University of Alicante |
Sabba M.F.,Civil Engineer
Open Construction and Building Technology Journal | Year: 2012
This paper shows the results of an experimental analysis on the bell tower of "Chiesa della Maddalena" (Mola di Bari, Italy), to better understand the structural behavior of slender masonry structures. The research aims to calibrate a numerical model by means of the Operational Modal Analysis (OMA) method. In this way realistic conclusions about the dynamic behavior of the structure are obtained. The choice of using an OMA derives from the necessity to know the modal parameters of a structure with a non-destructive testing, especially in case of cultural-historical value structures. Therefore by means of an easy and accurate process, it is possible to acquire in-situ environmental vibrations. The data collected are very important to estimate the mode shapes, the natural frequencies and the damping ratios of the structure. To analyze the data obtained from the monitoring, the Peak Picking method has been applied to the Fast Fourier Transforms (FFT) of the signals in order to identify the values of the effective natural frequencies and damping factors of the structure. The main frequencies and the damping ratios have been determined from measurements at some relevant locations. The responses have been then extrapolated and extended to the entire tower through a 3-D Finite Element Model. In this way, knowing the modes of vibration, it has been possible to understand the overall dynamic behavior of the structure. © Foti et al.; Licensee Bentham Open.