<abstract xmlns="http://www.w3.org/1999/xhtml">

Reliability analysis and stone columns techniques are widely used, with an increasing trend, in different geotechnical engineering problems. Design methods of stone columns is still based on deterministic approach, in spite some degree of uncertainties is associated with soil and stone column parameters. In the present work, reliability analysis of bearing capacity of stone columns is examined; using three methods of reliability analysis, First Order Second Moment FOSM, Point Estimate Method PEM, and Monte Carlo simulations MCs. Parametric analysis using all variables involved in stone columns design has been conducted. Distributions of random variables involved in stone columns design are considered either as normal or lognormal. The random variables correlation effect is examined. The study has allowed to evaluate parameter uncertainty effect on reliability index of stone columns, and has permitted to figure out reduced set of parameters that must be considered as random in reliability analysis of stone columns beside sensitivity analysis.
</abstract>

Department of Civil Engineering, Ecole Nationale Polytechnique

Reliability Analysis of Stone Columns Bearing Capacity

<abstract xmlns="http://www.w3.org/1999/xhtml">

The dynamic analysis of structures under seismic ground motions is a major issue in earthquake engineering. The seismic ground motions observed at the surface are variables in space and time. The main causes of this variability come from seismic waves propagation between the source and the site, and in particular the local geological site conditions. For this purpose, it is essential to consider all these factors of the spatial variability of seismic ground motion when representing seismic loading to be applied to any structure. Given the scarcity of real seismic records, many researchers suggest the use of artificial or synthetic seismic motions. The main objective of this study is the simulation of spatially variable artificial seismic motions by considering all fact of factors of the seismic spatial variability, especially site local conditions. In this sense, a simulation technique of spatially variable seismic motions is developed using the spectral representation method. By adopting the unconditional simulation approach, the target seismic motion in bedrock is defined by the Clough-Penzien spectral model and a specified coherency loss model. Then, the simulated ground motions in the bedrock are projected on the surface by considering amplification site effect. The results showed that the simulated artificial seismic motions are strongly conditioned by the local site conditions.
</abstract>

RISk Assesment & Management Laboratory (RISAM)

PhD, RISk Assesment & Management Laboratory (RISAM)

Lecturer, PhD, RISk Assesment & Management Laboratory (RISAM)

Simulation of Spatially Variable Artificial Earthquake: A Case Study of Different Site Conditions

<abstract xmlns="http://www.w3.org/1999/xhtml">

This paper focuses on the field of mechanical vibrations experimental analysis in hand arm vibrations (HAVs) for people who by the nature of their job are subject to the mechanical vibrations.
</abstract>

PhD.Eng., Technical University of Constructions Bucharest

prof.univ.dr.eng., Technical University of Constructions Bucharest

Partial Experimental Contributions on the Validation of Biomechanical Models of the Human Body Subjected to the Action of Mechanical Vibrations

<abstract xmlns="http://www.w3.org/1999/xhtml">

Nitrate is the most common form of nitrogen in water. The presence of nitrates in drinking water can harm human health, this is why the maximum concentration of nitrates in potable water is imposed by law. The main treatment technologies used for treating this kind of water are reverse osmosis, ion exchangers, electrodialysis and biological denitrification. The goal of this paper is to determine the efficiency of biofilters in reducing the ammonium concentrations in water, depending on the carrier/filtration media used in the biofilters, the C:N:P ratio used and contact time between water and the attached biomass. The paper is based on the result obtained during experimental tests in which the concentration of nitrates in the raw water was 150 mg/l.
</abstract>

Ph.D. Student, Technical University of Civil Engineering Bucharest

Prof.dr.eng., Technical University of Civil Engineering Bucharest

Conf.dr.chem.eng., Technical University of Civil Engineering Bucharest

Biological Denitrification of Water Intended for Human Consumption

<abstract xmlns="http://www.w3.org/1999/xhtml">

In this article, we present a method to obtain equations of non-degenerate conics in an initial Cartesian frame (<italic>xOy</italic>), starting from their canonical expressions in another Cartesian frame (<italic>x</italic>′′<italic>Cy</italic>′′).
</abstract>

General Equations of Non-Degenerate Conics

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Modelling in Civil Environmental Engineering

The roots of the Technical University of Civil Engineering of Bucharest (UTCB) go back in 1818 in the school of engineering concerning surveying and geodesy. In 1864 it became the "School of Bridges and Roads, Mines and Architecture", and from 1867 the "School of Bridges, Roads and Mines" and "the National School for Bridges and Roads" in 1888. In 1921, the "National School of Bridges and Roads" became the "Polytechnic School of Bucharest", where the civil engineers' training was carried out in the Civil Engineering Department which, in 1938, came to be known as the Faculty of Civil Engineering.  In 1948, due to the large development of the construction sector in Romania, an important part of the Polytechnic School was separated as the Civil Engineering Institute, including not only the Faculty of Civil Engineering, but also parts of other specializations related to constructions, as building services engineering, mechanical engineering for constructions, hydrotechnical engineering, roads, bridges, and railways construction or geodesy.  Starting from 1994, the Civil Engineering Institute became the Technical University of Civil Engineering Bucharest (UTCB).  The scientific results were published internally in the university scientific bulletin. Since 2005, the scientific bulletin of UTCB became the Mathematical Modelling in Civil Engineering journal.  The journal serves the Civil and Environmental Engineering community and our societies, aiming to effectively contribute to the development, innovation and progress in the field. Our journal publishes papers that present the state-of the-art results from research and practice.  Starting with 2021, the journal Mathematical Modelling in Civil Engineering expands its research fields and thus becomes: Modelling in Civil and Environmental Engineering, with a new ISSN: 2784-1391.  The journal Modelling in Civil and Environmental Engineering covers a wide range of topics from Civil and Environmental Engineering field and is ready to publish high quality standards, state-of the-art, peer-reviewed papers, coming from the academic and research community, and industry as well. MCEE addresses both theoretical developments and practical applications related to Civil and Structural Engineering, Geotechnics and Environmental Science (Soil, Water and Air Pollution, Wastewater Treatment Engineering), Thermal Sciences and Engineering (Thermodynamics, Transport Phenomena, Building Heat &amp; Mass Transfer, HVAC &amp; R), Hydraulic and Wind Engineering, Mechanical and Electrical Engineering in the Built Environment, Automation in Constructions, Roads, Bridges and Railways Constructions, Surveying and Geodesy and any other topics related to constructions and the built environment.  To be acceptable for publication in the MCEE journal, a manuscript must address valuable and of significant interest scientific issues for the Civil Engineering community, free of evident commercial or private interest.  The authors are requested to make sure that appropriate research ethical standards are strictly followed in their work, when submitted to MCEE.　  The MCEE staff fully supports the authors during the entire evaluation process and is committed to ensure that the ethical standards, related to submittal, review, and publication of manuscripts, will be strictly followed.  Rejection rate   22%   Archiving  Sciendo archives the contents of this journal in Portico - digital long-term preservation service of scholarly books, journals and collections.  Plagiarism Policy  The editorial board is participating in a growing community of Similarity Check System's users in order to ensure that the content published is original and trustworthy. Similarity Check is a medium that allows for comprehensive manuscripts screening, aimed to eliminate plagiarism and provide a high standard and quality peer-review process. 