Zs Szilvágyi

57035473800

Publications - 5

Verification of the Ramberg-Osgood material model in midas GTS NX with the modeling of torsional simple shear tests

Zs Szilvágyi R. P. Ray

Publication Name: Periodica Polytechnica Civil Engineering

Publication Date: 2018-05-22

Volume: 62

Issue: 3

Page Range: Unknown

Description:

This study focuses on the back analysis of a geotechnical laboratory test with nonlinear finite element modeling using the Ramberg-Osgood material model. This model has been used by several authors recently for nonlinear ground response analysis and it has been implemented by Midas into their commercial finite element code Midas GTS NX 2014. The verification of the model for 1D nonlinear site response analysis can be found in the documentation of the software package. In this study, Torsional Simple Shear tests were modeled and a comprehensive study was performed to provide verification of the material model for static torsional loading and axisymmetric conditions.

Open Access: Yes

DOI: 10.3311/PPci.11191

Effects of local ground conditions on site response analysis results in Hungary

O. Kegyes-Brassai Zs Szilvágyi None Wolf R. P. Ray

Publication Name: Icsmge 2017 19th International Conference on Soil Mechanics and Geotechnical Engineering

Publication Date: 2017-01-01

Volume: 2017-September

Issue: Unknown

Page Range: 2003-2006

Description:

Ground conditions play an important role for both seismic hazard assessment and structural design for seismic actions. Generally, 1D site response analysis is the first step toward evaluating local conditions. Often the process is simplified by applying a single reference peak ground acceleration general response spectrum based on soil category. Seismic waves are amplified selectively by near-surface soil deposits that possess strain dependent stiffness and damping parameters that vary with each layer as well as with depth. In order to take these local ground conditions into account, field investigations were carried out for this study. Seismic CPT and MASW measurements were used for determining in situ small strain stiffness profiles at different locations in Hungary. Results of the investigations were used as input data for ground response analyses. Results are presented to show benefits of the detailed investigations as compared to simplified analysis methods based on estimated soil parameters and to EC-8 design spectra.

Open Access: Yes

DOI: DOI not available

Soil shear modulus from resonant column, torsional shear and bender element tests

P. Hudacsek Zs Szilvágyi R. P. Ray

Publication Name: International Journal of Geomate

Publication Date: 2016-01-01

Volume: 10

Issue: 2

Page Range: 1822-1827

Description:

This study compares results from three different testing methods: Resonant Column, Torsional Simple Shear, and Bender Element tests to determine shear modulus. The resonant column and torsional shear tests were performed on the same hollow cylinder specimen. The bender element test was performed on a triaxial specimen with the same void ratio and confining stress as well as others. Several effects were studied, among them confining stress, shear strain amplitude and for the bender element, anisotropic confinement. Testing methods and data analysis are discussed in the paper because data interpretation is very important in these tests. Results showed that the shear modulus values were almost identical between the resonant column and torsional shear but varied somewhat with the bender element results. Further research will focus on influence of stress anisotropy preparation methods.

Open Access: Yes

DOI: 10.21660/2016.20.39871

Seismic performance evaluation of an irregular RC frame building

Zs Szilvágyi R. P. Ray

Publication Name: Geotechnical Engineering for Infrastructure and Development Proceedings of the Xvi European Conference on Soil Mechanics and Geotechnical Engineering Ecsmge 2015

Publication Date: 2015-01-01

Volume: 7

Issue: Unknown

Page Range: 4185-4190

Description:

This paper focuses on overcoming difficulties associated with the assessment of a multi-story reinforced concrete frame building constructed in several phases over time, with an irregular layout. Trying to develop a coherent, safe and sensible design in such a case is indeed a challenge for structural and geotechnical engineers. The retrofitting problem is made worse by incomplete data, a building with shallow and deep foundations, and architectural "re-purposing" of the entire structural assembly. A state-of-the art seismic performance evaluation according to Eurocode 8-3 is presented as a case study, with special emphasis on the topics of numerical modeling and foundation modeling. Potential modeling simplifications are considered as well.

Open Access: Yes

DOI: DOI not available

Measuring and modeling the dynamic behavior of Danube Sands

Zs Szilvágyi R. P. Ray

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: Unknown

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: Yes

DOI: DOI not available