Free-Field Seismic Response Analysis

2018 ◽  
Vol 9 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Andrea Angina ◽  
Andrea Steri ◽  
Stefano Stacul ◽  
Diego Lo Presti
Keyword(s):  
Seismic Response ◽  
Free Field ◽  
Ground Level ◽  
Response Spectra ◽  
Site Investigation ◽  
Building Code ◽  
Elastic Response ◽  
Response Analysis ◽  
Elastic Response Spectra ◽  
The Time Domain

This paper shows the results of free-field seismic response analyses (SRA), that were performed for the subsoil conditions of Piazza dei Miracoli in Pisa. The site investigation and in particular the shear wave velocity profile is extended down to 120 m below the ground level. One-dimensional SRA were carried out by using three computer codes, EERA, STRATA and ONDA. The first two codes perform the analyses in the frequency domain considering a linear-equivalent soil model. ONDA analyses the problem in the time domain assuming a true non-linear soil behaviour. In particular, the Ramberg-Osgood constitutive model, coupled with a modified Masing criterion was assumed. The computed elastic response spectra were compared to those prescribed by the Italian Building Code, which represents the Italian implementation of Eurocodes. Some details concerning the response spectra prescribed by Italian Building Code are also given.

Sensitivity analysis of geotechnical site conditions effect on the seismic response of a saturated inhomogeneous poroviscoelastic soil profile

2018 ◽  
Vol 15 (6) ◽  
pp. 661-677 ◽  
Author(s):  
Toufiq Ouzandja ◽  
Mohamed Hadid
Keyword(s):  
Soil Properties ◽  
Seismic Response ◽  
Pore Water ◽  
Soil Profile ◽  
Water Saturation ◽  
Free Field ◽  
Response Spectra ◽  
Response Analysis ◽  
Content Type ◽  
Linear And Nonlinear

Purpose This paper aims to present the investigation of the linear and nonlinear seismic site response of a saturated inhomogeneous poroviscoelastic soil profile for different soil properties, such as pore-water saturation, non-cohesive fines content FC, permeability k, porosity n and coefficient of uniformity Cu. Design/methodology/approach The inhomogeneous soil profile is idealized as a multi-layered saturated poroviscoelastic medium and is characterized by the Biot’s theory, with a shear modulus varying continuously with depth according to the Wichtmann’s model. Seismic response analysis has been evaluated through a computational model, which is based on the exact stiffness matrix method formulated in the frequency domain assuming that the incoming seismic waves consist of inclined P-SV waves. Findings Unlike the horizontal seismic response, the results indicate that the vertical one is strongly affected by the pore water saturation. Moreover, in the case of fully saturated soil profile, the same vertical response spectra are found for the two cases of soil behavior, linear and nonlinear. Originality/value This research is a detailed study of the geotechnical soil properties effect on the bi-directional seismic response of saturated inhomogeneous poroviscoelastic soil profile, which has not been treated before; the results are presented in terms of the peak acceleration ratio, as well as the free-field response spectra and the spectral ratio (V/H).

scholarly journals The seismic microzonation of level 3 of Sant’Agata Fossili (northern Italy) based on a multidisciplinary approach

2014 ◽  
Vol 57 (1) ◽  
Author(s):  
Giuseppe Di Capua ◽  
Massimo Compagnoni ◽  
Giuseppe Di Giulio ◽  
Marco Marchetti ◽  
Giuliano Milana ◽  
...  
Keyword(s):  
Seismic Response ◽  
Multidisciplinary Approach ◽  
Response Spectra ◽  
Northern Italy ◽  
Seismic Microzonation ◽  
Elastic Response ◽  
Local Seismic Response ◽  
Elastic Response Spectra ◽  
Level 3 ◽  
Local Geology

<p>In this paper the results of a detailed seismic microzonation, performed at Sant’Agata Fossili (Piemonte region, northern Italy) are presented. We study the local seismic response of this small village using a level 3, that is the most accurate level following the Italian code of seismic microzonation. The activity steps consist in a gradual widening of knowledge of the different aspects of the amplification phenomena. A multidisciplinary approach has been performed to obtain the local seismic response: including a study of local geology, geophysical and geotechnical characterization of the lithologies, and numerical and experimental analyses. We finally compare the obtained elastic response spectra to the prescribed spectra of the Italian Building Code (in Italian: Norme Tecniche per le Costruzioni). Our results show the geologic and geophysical differences of the subsoil, that produce different local seismic response in terms of amplification factors and acceleration response spectra.</p>

scholarly journals Control Spectra for Quito

2016 ◽  
Author(s):  
Roberto Aguiar ◽  
Alicia Rivas-Medina ◽  
Pablo Caiza ◽  
Diego Quizanga
Keyword(s):  
Urban Areas ◽  
Slip Rate ◽  
Response Spectra ◽  
Elastic Response ◽  
Minimum Size ◽  
Physical Parameters ◽  
North Central ◽  
South Central ◽  
Elastic Response Spectra ◽  
Maximum Minimum

Abstract. The Metropolitan District of Quito is divided into five areas: south, south-central, central, north-central and north. It is located on or very close to segments of reverse blind faults: Puengasí, Ilumbisí-La Bota, Carcelen-El Inca, Bellavista-Catequilla and Tangahuilla as indicated in Alvarado et al. (2014), making it one of the most seismically dangerous cities in the world. For each of the urban areas of Quito, elastic response spectra are presented in this paper, which are found using some of the new models of the PEER's NGA-West2 Program, models developed by: Abrahamson et al. (2013), Campbell and Borzognia (2013), and Chiou and Youngs (2013). These spectra are calculated considering the maximum amount that could be generated by the rupture of each fault segments, and taking into account the soil type that exists in each zone according to the Norma Ecuatoriana de la Construcción 2015 (NEC-15). Subsequently, the recurrence period of earthquakes of high magnitude in each fault segment is determined from the physical parameters of the fault segments (size of the fault plane and slip rate), and considering that the fault can break in earthquakes of magnitude less than the expected maximum (minimum size 5.0 Mw). For this, the pattern of recurrence of type GR earthquakes (Gutenberg and Richter, 1944) with double truncation magnitude (Mmin and Mmax) proposed by Cosentino et al. (1977) is used.

Seismic Analysis of High Pier Three-Span Continuous Bridge

2015 ◽  
Vol 744-746 ◽  
pp. 890-893
Author(s):  
Xun Wu ◽  
Yong Lan Zhang
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Response Spectra ◽  
Elastic Response ◽  
Modeling And Analysis ◽  
Continuous Beam Bridge ◽  
Comparison Results ◽  
Elastic Response Spectra ◽  
Nonlinear Time History

In this paper, SAP2000 and ANSYS software are used to modeling and analysis athree-span continuous beam bridge with high piers case study.By using differentbearing types and combinations to form different options, create two finiteelement models.Analysis dynamic characteristics ,elastic response spectra,linear time history and nonlinear time history .And focus on comparing dynamiccharacteristics of the earthquake response of the two programs .Running outputdata processing and comparison results show that the application of thedifferent parameters of the rational combination of rubber bearing basin bridgearrangement has better seismic performance.

Study on the Characters of Seismic Response Spectra Based on China Financial Information Mansion

2014 ◽  
Vol 580-583 ◽  
pp. 1729-1733
Author(s):  
Ming Li ◽  
Yuan Qing Wang ◽  
Wei Tao ◽  
Bin Wang ◽  
Qing Xian Yu ◽  
...  
Keyword(s):  
Seismic Response ◽  
Response Spectrum ◽  
Response Spectra ◽  
Financial Information ◽  
Amplification Coefficient ◽  
Response Analysis ◽  
Magnification Factor ◽  
Characteristic Period ◽  
Seismic Coefficient ◽  
Dynamic Magnification Factor

Rare study is done on floor response spectrum of super-high rise building, but it is an important condition for the seismic response analysis of floor subsidiary structure. Therefore, based on the early calculation model of China Financial Information Mansion, the floor response spectrum is calculated under different input ground motion. The floor and ground response spectrum is compared with each other from the seismic coefficient, dynamic amplification coefficient, characteristic period and the form of response spectrum. The results shows that: the floor seismic coefficient and the magnification coefficient are greater or smaller than the ground ones, the biggest difference of which is nearly 1 times; all the floor character period are greater than the ground ones, the biggest difference of which is over 60%; there are obvious differences between the floor and ground dynamic magnification factor spectra form under some conditions, of which the second peak of the former one is probably very large, even near to the peak of the first one, while the latter has no such phenomenon. Therefore, during the process of calculating the seismic response of floor subsidiary structure, it is necessary to consider the change of floor seismic coefficient, dynamic magnification factor, characteristic period and spectra form based on the main structure.

Response Modification Factor for Y-Eccentric-Braced Steel Frame Structures Designed Based on Chinese Code

2014 ◽  
Vol 580-583 ◽  
pp. 1449-1457
Author(s):  
Wen Xia Yang ◽  
Qiang Gu ◽  
Ping Zhou Cao ◽  
Rong Jin Shi
Keyword(s):  
Pushover Analysis ◽  
Design Procedure ◽  
Response Spectra ◽  
Elastic Response ◽  
Base Shear ◽  
Response Modification Factor ◽  
Linear Elastic ◽  
Elastic Response Spectra ◽  
Modification Factor ◽  
Steel Frame Structures

In current seismic design procedure, structure base shear is calculated according to the linear elastic response spectra divided by the response modification factor, which accounts for ductility and overstrength of a structural system. In this paper, the response modification factors of Y-eccentric braced steel frames (YECBF) designed based on Chinese Code were evaluated by an improved pushover analysis on 12 examples with various stories and spans lengths. According to the analysis results, the effects of fundamental periods, storey numbers, and spans of frames on the behavior factor were studied. In the end, an appropriate response modification factor was proposed for YECBF designed base on Chinese Code.

NGA Ground Motion Model for the Geometric Mean Horizontal Component of PGA, PGV, PGD and 5% Damped Linear Elastic Response Spectra for Periods Ranging from 0.01 to 10 s

2008 ◽  
Vol 24 (1) ◽  
pp. 139-171 ◽  
Author(s):  
Kenneth W. Campbell ◽  
Yousef Bozorgnia
Keyword(s):  
Standard Deviation ◽  
Ground Motion ◽  
Geometric Mean ◽  
Response Spectra ◽  
Horizontal Component ◽  
Elastic Response ◽  
Motion Model ◽  
Linear Elastic ◽  
Ground Motion Model ◽  
Elastic Response Spectra

We present a new empirical ground motion model for PGA, PGV, PGD and 5% damped linear elastic response spectra for periods ranging from 0.01–10 s. The model was developed as part of the PEER Next Generation Attenuation (NGA) project. We used a subset of the PEER NGA database for which we excluded recordings and earthquakes that were believed to be inappropriate for estimating free-field ground motions from shallow earthquake mainshocks in active tectonic regimes. We developed relations for both the median and standard deviation of the geometric mean horizontal component of ground motion that we consider to be valid for magnitudes ranging from 4.0 up to 7.5–8.5 (depending on fault mechanism) and distances ranging from 0–200 km. The model explicitly includes the effects of magnitude saturation, magnitude-dependent attenuation, style of faulting, rupture depth, hanging-wall geometry, linear and nonlinear site response, 3-D basin response, and inter-event and intra-event variability. Soil nonlinearity causes the intra-event standard deviation to depend on the amplitude of PGA on reference rock rather than on magnitude, which leads to a decrease in aleatory uncertainty at high levels of ground shaking for sites located on soil.

Study on the Ground Response Analysis for Stiff Soil

2014 ◽  
Vol 915-916 ◽  
pp. 122-125
Author(s):  
Xiao Fei Li ◽  
Rui Sun ◽  
Xiao Bo Yu
Keyword(s):  
Seismic Response ◽  
Working Conditions ◽  
Strong Motion ◽  
Response Spectra ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Ground Response Analysis ◽  
Ground Acceleration ◽  
Strong Motion Records ◽  
Stiff Soil

In order to test the applicable of the seismic response analysis procedures SHAKE2000 and LSSRLI-1 for class ІІ site, 17 stations and 35 underground strong motion records of KiK-net are selected from Class ІІ site. 210 working conditions are used to verify the applicability of the two soil seismic response analysis programs at Class ІІ site. These two programs are used to calculate the selected working conditions, giving the peak acceleration of the ground, the shear strain and the ground acceleration response spectra. By analyzing the results of the two programs and the measured results to assess the degree of difference between the two methods and which program is closer to the real situation. Studies have shown that in class ІІ site, in most cases, the results of SHAKE2000 and LSSRLI-1 differ little. While comparing with the actual records, SHAKE2000 is closer to the strong motion records.

scholarly journals A MPM framework for large deformation seismic response analysis

2021 ◽  
Author(s):  
Marc Kohler ◽  
Andreas Stoecklin ◽  
Alexander M. Puzrin
Keyword(s):  
Boundary Conditions ◽  
Seismic Response ◽  
Large Deformation ◽  
Free Field ◽  
Large Mass ◽  
Material Point ◽  
Ground Movement ◽  
Response Analysis ◽  
Seismic Response Analysis ◽  
Seismic Triggering

Landslides are often triggered by earthquakes and can cause immense damage due to large mass movements. To model such large-deformation events, the material point method (MPM) has become increasingly popular in recent years. A limitation of existing MPM implementations is the lack of appropriate boundary conditions to perform seismic response analysis of slopes. In this article, an extension to the basic MPM framework is proposed for simulating the seismic triggering and subsequent collapse of slopes within a single analysis step. Original implementations of a compliant base boundary and free-field boundary conditions in the MPM framework are presented, enabling the application of input ground motions while accounting for the absorption of outgoing waves and the free-ground movement at the lateral boundaries. An example slope is analysed to illustrate the proposed procedure and to benchmark it against the results obtained using an independent simulation technique, based on a three-step FE analysis. The comparison generally shows a good agreement of the results obtained from the two independent procedures and highlights advantages of the presented “all-in-one” MPM approach, in particular for long duration strong motions.

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