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Found 6374 publications

Integrating nonlinear pile behavior with standard structural engineering software

No authors available

Publication Name: 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013

Publication Date: 2013-01-01

Volume: 4

Issue:

Page Range: 2869-2872

Description:

It is common in the practice of bridge design to analyze the superstructure, substructure, and foundation components separately. Applying this kind of modeling, soil-structure interaction effects can only be approximated with moderate accuracy. The foundation stiffness can greatly influence the internal forces, stresses, and displacements of superstructure. This is especially true for portal frame and integral bridges. Better modeling of soil-structure interaction can use three-dimensional geotechnical FEM programs, where the true soil-stucture environment can be analyzed. It is possible to use nonlinear constitutive models; capable of modeling soil behavior accurately, however it is difficult, time consuming, and costly in day-to-day practice.

Open Access: No

DOI: DOI not available

Laboratory tests and numerical modeling for embankment foundation on soft chalky silt using deep-mixing

No authors available

Publication Name: 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013

Publication Date: 2013-01-01

Volume: 3

Issue:

Page Range: 2521-2524

Description:

The deep-mixing is nowadays world-wide accepted method as a ground treatment technology to improve the permeability, strength and deformation properties of soils. Binders, such as lime or cement are mixed in-situ with the soil by rotating mixing tools. The method is undergoing rapid development, particularly with regard to its range of applicability, cost effectiveness and environmental advantages. The paper describes the results of laboratory tests on chalky silt samples mixed with cement of different content. The influence of the different mixing parameters on the unconfined compression strength and deformation modulus is shown and evaluated. Typical results of the laboratory tests were used in numerical modeling with PLAXIS 3D as input parameters to study the behavior of a 4 m high embankment constructed on this soil improved by deep mixed columns with different spacing and diameters. The parameters of the soil improvement technique were analyzed to study their influence on the settlement and the stability of the embankment. The trends of the calculation outputs are shown and evaluated.

Open Access: No

DOI: DOI not available

Applying earthquake risk analysis methods to a town in Hungary

No authors available

Publication Name: 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013

Publication Date: 2013-01-01

Volume: 2

Issue:

Page Range: 1519-1522

Description:

Determining the earthquake risk of buildings in a town or settlement has lately become a more prominent issue. The process can provide important data for governments, authorities, disaster management and insurance companies to better understand risks to many buildings and engineering systems rather than a single building. This paper addresses the rapid evaluation of a large number of similar buildings in one area using a forecasting approach. Back-casting mainly considers the effect of previous earthquakes by listing and categorizing the damaged buildings and casualties. Forecasting offers a method to evaluate the possible damages in advance, however many uncertainties need to be taken into consideration. A fast and simple method should be developed to avoid the time and expertise required from research-based approaches. The steps involve determination of the hazard, assessing building stock, and computing vulnerability. The method for determination of vulnerability functions is a non-linear static analysis using a bilinear approximation of the capacity curve, assuming first mode force distribution and mode shape thus linear strength distribution. From the curve of the seismic demand and the shear capacity of the building, the vulnerability function of the building can be obtained. These vulnerability functions should be derived for typical layouts; offering a family of curves allowing the experts to decide the vulnerability category of a specific building on-site based on visual screening. With the given value of possible PGA (peak ground acceleration), expected damages can then be estimated.

Open Access: No

DOI: DOI not available

Analysis and design of piles for dynamic loading

No authors available

Publication Name: 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013

Publication Date: 2013-01-01

Volume: 4

Issue:

Page Range: 2839-2842

Description:

With the acceptance of Eurocode 8 in Hungary a new level of seismic design is now necessary. This paper outlines some of the past history and present implementation of foundation design for seismic loading as practiced in Hungary. It shortly describes the possibilities of modeling foundations (fix support, linear elastic support, non-linear elastic support) during the design of the superstructure, and introduces the Hungarian practice. The influence of the different support's methods for the bearing forces/stresses of a superstructure is analyzed on a typical reinforced concrete office building using SAP2000 finite element software. The results of the calculation are compared through the moment of a column, the deflection and the support reaction.

Open Access: No

DOI: DOI not available

Measuring and modeling the dynamic behavior of Danube Sands

No authors available

Publication Name: 18th International Conference on Soil Mechanics and Geotechnical Engineering: Challenges and Innovations in Geotechnics, ICSMGE 2013

Publication Date: 2013-01-01

Volume: 2

Issue:

Page Range: 1575-1578

Description:

The adaptation of Eurocode 8 and development of high speed rail system in Hungary has created a greater need to define dynamic behavior of local soil groups. Danube sands compose an important segment of these soils and present the geotechnical engineer with several design challenges. The soils are present at river crossings and major development parcels throughout Hungary. Although the engineering behavior of these sands can vary over a wide range, they retain some common characteristics that will help the engineer to make decisions about geotechnical and structural designs. Samples of Danube sands were brought in the laboratory for dynamic testing, which included resonant column and torsional simple shear testing. This paper summarizes the dynamic behavior of this typical local soil group with emphasis on the dynamic properties themselves. Researches will find the methods and approach to evaluating properties helpful in their work while design engineers will understand how these properties are applied.

Open Access: No

DOI: DOI not available

Investigation on the tribological behavior of thermal sprayed coatings applied to cylinder liners - Influence of chromium content on wear resistance of plasma transferred wire arc coatings

No authors available

Publication Name: 5th World Tribology Congress, WTC 2013

Publication Date: 2013-01-01

Volume: 1

Issue:

Page Range: 305-308

Description:

Open Access: No

DOI: DOI not available

Thermal, thermomechanical and structural properties of recycled polyethylene terephthalate (rPET)/waste marble dust composites

Ferenc Ronkay László Lendvai Tej Singh

Publication Name: Heliyon

Publication Date: 2024-02-15

Volume: 10

Issue: 3

Page Range: Unknown

Description:

The main objective of this work is to review the capability of using waste marble dust (MD) particles as reinforcing materials in recycled polymeric composites to achieve environmentally friendly materials. In the present study, polymer composites were fabricated from recycled polyethylene terephthalate (rPET) and MD and then analyzed for their structural and thermal properties. Preparation of rPET-based composites containing 0–20 wt% MD was carried out through extrusion and injection molding. For their characterization Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and dynamic mechanical analysis (DMA) were applied. The DSC analysis revealed a nucleating effect of MD on rPET, which was manifested in a higher crystallization temperature (196.7 °C ⇒ 204.4 °C); however, the marble particles were also found to hamper chain mobility, thereby decreasing the crystallinity ratio (23.7 % ⇒ 19.2 %) of rPET and altering its crystalline structure. According to the TGA measurements, a slight increase occurred in the thermal stability of rPET, its major decomposition temperature increased from 446 °C to 451 °C when 20 wt% MD was incorporated into it. DMA showed an improved stiffness in the entire investigated temperature range for MD-filled composites versus neat rPET. Additionally, several factors were derived from the DMA data, including the effectiveness factor, degree of entanglement, and reinforcing efficiency factor which all suggested a decent interaction between the components indicating a proper reinforcing ability of marble powder. However, above 5 wt% MD content the reinforcing efficiency deteriorated due to the agglomeration of filler particles, which was also supported by scanning electron microscopic images.

Open Access: Yes

DOI: 10.1016/j.heliyon.2024.e25015

The utility of the ‘Arable Weeds and Management in Europe’ database: Challenges and opportunities of combining weed survey data at a European scale

Alicia Cirujeda Michael Glemnitz Jana Bürger Guillaume Fried Jevgenija Ņečajeva Lena Ulber Silvia Fogliatto Michaela Kolářová Eva Hernández Plaza Matthias Schumacher Bärbel Gerowitt G. Pinke Sandrine Petit Christoph Redwitz Helen Metcalfe Denise Fu Dostatny José Luis González-Andújar Francesco Vidotto Jordi Izquierdo

Publication Name: Weed Research

Publication Date: 2023-02-01

Volume: 63

Issue: 1

Page Range: 1-11

Description:

Over the last 30 years, many studies have surveyed weed vegetation on arable land. The ‘Arable Weeds and Management in Europe’ (AWME) database is a collection of 36 of these surveys and the associated management data. Here, we review the challenges associated with combining disparate datasets and explore some of the opportunities for future research that present themselves thanks to the AWME database. We present three case studies repeating previously published national scale analyses with data from a larger spatial extent. The case studies, originally done in France, Germany and the UK, explore various aspects of weed ecology (community composition, management and environmental effects and within-field distributions) and use a range of statistical techniques (canonical correspondence analysis, redundancy analysis and generalised linear mixed models) to demonstrate the utility and versatility of the AWME database. We demonstrate that (i) the standardisation of abundance data to a common measure, before the analysis of the combined dataset, has little impact on the outcome of the analyses, (ii) the increased extent of environmental or management gradients allows for greater confidence in conclusions and (iii) the main conclusions of analyses done at different spatial scales remain consistent. These case studies demonstrate the utility of a Europe-wide weed survey database, for clarifying or extending results obtained from studies at smaller scales. This Europe-wide data collection offers many more opportunities for analysis that could not be addressed in smaller datasets; including questions about the effects of climate change, macro-ecological and biogeographical issues related to weed diversity as well as the dominance or rarity of specific weeds in Europe.

Open Access: Yes

DOI: 10.1111/wre.12562

Testing the speed-up of parallel discrete event simulation in heterogeneous execution environments

No authors available

Publication Name: 11th International Industrial Simulation Conference 2013, ISC 2013

Publication Date: 2013-01-01

Volume:

Issue:

Page Range: 101-107

Description:

This paper deals with the experimental testing and verification of the earlier proposed load balancing and coupling factor criteria for the conservative parallel discrete event simulation in heterogeneous execution environments whether they can ensure a good speed-up. The definition of the relative speed-up is extended to the heterogeneous systems in a natural way. This definition is used to measure the efficiency of the parallel simulation executed by heterogeneous systems. A closed queueing network is used as the simulation model, and it is executed on different heterogeneous test systems. Among several scenarios, it is demonstrated on the example of a heterogeneous system containing 87 CPU cores of 5 different types that a good speed-up can be achieved using the load balancing and coupling factor criteria. It is shown that the extension of the definition of the relative speed-up to the heterogeneous systems made it easy to judge the speed-up of parallel discrete event simulation in heterogeneous execution environments.

Open Access: No

DOI: DOI not available