Search results for "Civil Engineering"
showing 10 items of 1216 documents
New simplified approach for obtaining a reliable plateau value in fatigue analysis of bituminous materials
2017
The Plateau Value (PV) based on the Ratio of Dissipated Energy Change (RDEC) approach has been proven to provide a unique relationship with the fatigue life, N-f, independent of loading mode, temperature and frequency. In this paper, a new simplified approach is proposed to compute the unique energy parameter PV. The results of this study show that applying the proposed method allows a unique fatigue power law to be produced and eliminates the ambiguity and variability in calculating PV. However, the study also shows that the PV-N-f fatigue curves for bituminous materials are dependent on material type which is contradictory to other studies dealing with PV. The study also highlights the im…
A new and simplified approach to assess the pavement surface micro- and macrotexture
2017
Abstract Road safety depends on pavement skid resistance and surface texture. Skid resistance mainly depends on micro-texture and macrotexture. Skid and texture measurements on samples, in the laboratory, at the preliminary stage of the design, would enhance the design in terms of timing, costs, and reliability. Consequently, this study aims at setting up and validating simple methods for assessing surface texture and skid resistance based on core/sample measurements. Experiments were carried out and predictive relationships were set up to explain and predict results. Under given conditions, miniaturised macro-and microtexture tests (modified EN 13036-1 and modified EN 13036-4, respectively…
Failure by corrosion in PC bridges: A case history of a viaduct in Italy
2016
Purpose The paper illustrates a viaduct collapse due to corrosion phenomena. Moreover, a contribution to the issues related to both the control of existing structures and design methods to be followed for the construction of new buildings is provided. Design/methodology/approach The objectives were achieved by in situ observations and numerical analyses. The effects of corrosion phenomena are investigated, and the progressive collapse analysis is provided to be helpful in this case. Findings The damages induced by corrosion phenomena have caused the collapse of the viaduct taken in to account. The performed numerical analyses were able to reproduce the effects of corrosion in terms of redu…
Reducing the noise pollution level along main roads in Sibiu, Romania by optimizing the traffic flow
2017
Noise pollution is one of the most important negative effects of road traffic, especially in cities. The current paper presents an attempt to reduce the noise level created by the road traffic along some main roads in the city of Sibiu, Romania by suggesting ways to optimize the traffic flow. The number of cars and the resulting noise levels were recorded in a key area of Sibiu. The noise levels were compared to standards and to measurements taken in areas with less traffic. Then, they were fed, together with road geometry data, into a specialized simulation software that allowed the computer-aided reproduction of the traffic flow, but also the modifying of conditions such as the road geome…
Innovative modeling of tuned liquid column damper controlled structures
2016
In this paper a different formulation for the response of structural systems controlled by Tuned Liquid Column Damper (TLCD) devices is developed, based on the mathematical tool of fractional calculus. Although the increasing use of these devices for structural vibration control, it has been demonstrated that existing model may lead to inaccurate prediction of liquid motion, thus reflecting in a possible imprecise description of the structural response. For this reason the recently proposed fractional formulation introduced to model liquid displacements in TLCD devices, is here extended to deal with TLCD controlled structures under base excitations. As demonstrated through an extensive expe…
Incremental dynamic based fragility assessment of reinforced concrete structures: Stationary vs. non-stationary artificial ground motions
2017
Abstract Artificial and natural records are commonly employed by researches and practitioners to perform refined seismic assessments of structures. The techniques for the generation of artificial records and their effectiveness in producing signals which are significantly representative of real earthquakes are still debated as well as results of the consequent seismic assessment to expect from their application. The paper presents an in-depth comparative study highlighting the effect of employing different typologies of artificial ground motion records on seismic assessment results, especially addressing seismic fragility curves. Three sets of 50 stationary, nonstationary evenly modulated a…
Brownfield management opportunities to reduce the back pressure effects on the gas wells
2017
Gas mature fields are associated with challenges to optimize the hydrocarbon flow from reservoir to the sales point in a cost effective manner due to declining well productivity. Laslau Mare field is a mature gas field in Transylvanian basin (Mures County) developed in 1970s and is producing∼99% methane with low water-gas ratio. As any brown field, the state of depleted reservoir will generate several constraints for gas flow from formation to surface facilities and further to delivery point. During the exploitation has been observed that the operation conditions are facing with unstable pressure in the system due to low demand. Therefore, the back pressure effect will affect the wells in t…
Performance of two innovative stress sensors imbedded in mortar joints of new masonry elements
2021
Abstract Many historical cities enjoy the presence of masonry buildings with inestimable historical, artistic and cultural value. Old masonry buildings often suffer structural deficiencies, design faults and materials aging process. In recent years, many researchers focused their attention on the opportunities that structural health monitoring (SHM) can ensure for the health state of existing masonry structures, where damage can be difficult to be promptly predicted, pontentially causing abrupt collapses, with high risks for the community. This paper presents an experimental study on the effectiveness of two types of stress sensor for SHM of new masonry elements. Ceramic piezoelectric senso…
Upwards - Vertical extensions of masonry built heritage for sustainable and antifragile urban densification
2021
Abstract Urban densification represents one of the biggest universal challenges of contemporary cities: the increase of urban population requires new spaces to accommodate the growing demand for housing, working and tertiary activities. However, the land available for new constructions in highly urbanized areas is very limited. In this framework, the vertical extension of existing buildings is the most sustainable strategy and fascinating. Masonry structures , constituting a major part of the built stock in the historical city centres of several European countries, are particularly suitable for vertical addition of extra-floors, since they generally exhibit an adequate overstrength for bear…
An exploratory study for analyzing the energy savings obtainable by reshaping processes of sheet metal based components
2017
Abstract Producing materials causes about 25% of all anthropogenic CO2 emissions. Reshaping could be one of the most efficient strategy to foster material reuse and lower the environmental impact due to material production. Sheet metal forming processes can be applied to reshape sheet metal based component. This research field is still almost unexplored and the actual environmental impact saving potential has not been quantified. The present paper aims at starting to cover this research gap, a modeling effort to quantify the environmental impact saving of reshaping is proposed. Primary energy demand for conventional recycling and reshaping are quantified and compared. Primary energy savings…