scholarly journals Nonlinear Seismic Response Characteristics of CAP1400 Nuclear Island Structure on Soft Rock Sites

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Furong Li ◽  
Guoxing Chen
Keyword(s):  
Seismic Response ◽  
Shear Wave ◽  
Ground Motion ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Nuclear Power ◽  
Response Spectrum ◽  
Soft Rock ◽  
Relative Displacement ◽  
Island Structure

CAP1400 nuclear island structure is an advanced and novel nuclear power plant structure. In order to explore the seismic response characteristics of CAP1400 nuclear island structure on soft rock sites, a three-dimensional refined nonlinear seismic response analysis model was established for a soft rock foundation-nuclear island structure system using ABAQUS software. The influences of the input ground motion intensity and the frequency spectrum characteristics on the acceleration, relative displacement, and floor response spectrum, as well as the critical shear wave velocity of nonbedrock sites for CAP1400 nuclear island structure, were proposed. The results suggested that the increasing amplitude of the peak acceleration and relative displacement of nuclear island structure decreased as the soft rock site entered a nonlinear state, and the high-frequency components of the input ground motion became more abundant. Specifically, the earthquake response was the largest at the cooling water tank on the top of the shield building, which was the focus of the seismic research on nuclear island structure. Due to the influence of the ground motion frequency spectrum characteristics and the nonbedrock site effect, the peak acceleration, peak relative displacement, and acceleration response spectrum of the nuclear island structure showed different changing trends for the near-field and far-field ground motions. Based on the influence of the site shear wave velocity on the seismic response of nuclear island structure, it was recommended that the critical shear wave velocity of nonbedrock sites for CAP1400 nuclear island structure should be 1250 m/s, and the nuclear island structure-foundation dynamic interaction could be ignored at this time. The research conclusions could provide some technical support and theoretical basis for the construction and seismic performance research of CAP1400 and other nuclear power plants.

Shear-Wave Velocity and Seismic Response of Near-Surface Sediments in Charleston, South Carolina

2006 ◽  
Vol 96 (5) ◽  
pp. 1897-1914 ◽  
Author(s):  
R. D. Andrus ◽  
C. D. Fairbanks ◽  
J. Zhang ◽  
W. M. Camp ◽  
T. J. Casey ◽  
...  
Keyword(s):  
South Carolina ◽  
Seismic Response ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Surface Sediments ◽  
Near Surface

Ground motion prediction equation for Taiwan subduction zone earthquakes

2020 ◽  
Vol 36 (3) ◽  
pp. 1331-1358 ◽  
Author(s):  
Van-Bang Phung ◽  
Chin Hsiung Loh ◽  
Shu Hsien Chao ◽  
Norman A Abrahamson
Keyword(s):  
Shear Wave ◽  
Ground Motion ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Prediction Equation ◽  
Motion Prediction ◽  
Ground Motion Prediction Equation ◽  
Ground Motion Prediction ◽  
Magnitude Scaling ◽  
Site Term

A ground motion prediction equation (GMPE) is presented for computing the median and standard deviation of peak ground acceleration (PGA) and 5% damped pseudo-spectral acceleration (PSA) for periods between 0.01 s and 5.0 s for probabilistic seismic hazard analysis (PSHA) and engineering applications in Taiwan. An integrated strong motion dataset consisting of two subduction earthquake regions was selected from 3314 recordings from Taiwan with M4.5 to M7.1 and 3376 recordings from Japan with M6.5 to M9.1. This dataset was then used to validate, and refit where necessary, the function form provided by Abrahamson et al. for application to Taiwan subduction earthquakes. The proposed model accounts for the extrapolation behaviors associated with the large-magnitude scaling and the near-source scaling terms, both of which were developed empirically by using the combined Taiwan–Japan dataset. The distance attenuation and site term were developed specifically for the Taiwan region. The site term is based on two parameters; the time-averaged shear wave velocity of the top 30 m depth ( VS30) and the depth-to-the-shear wave velocity horizon of 1.0 km/s ( Z1.0).

Analysis on the Bias of Seismic Ground Motion Prediction in a Shallow Stiff-Soil Site by LSSRL-1 Program

2014 ◽  
Vol 915-916 ◽  
pp. 18-21
Author(s):  
Zhuo Shi Chen ◽  
Xiao Ming Yuan ◽  
Shang Jiu Meng
Keyword(s):  
Shear Wave ◽  
Ground Motion ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Dynamic Parameters ◽  
Ground Motion Prediction ◽  
Blind Prediction ◽  
Soil Site ◽  
Parkfield Earthquake ◽  
Stiff Soil

The main causes of the ground motion blind prediction bias are the variability of the adopted program, the shear-wave velocity of the site, and the soil nonlinear dynamic parameters. By considering the variability of shear-wave velocity and the dynamic parameters, this essay used LSSRLI-1 Codes and Mw6.0 seismic record of Parkfield earthquake to calculate ground responses of 9 different conditions at Turkey Flat site. The authors believe that the variability of shear-wave velocity caused the dominant impact to the blind prediction of this shallow stiff-soil site. That impact is much greater than that of the dynamic parameters. LSSRLI-1 program may either underestimate the ground response of the shallow stiff-soil site or may overestimate it, so we should combine the specific site conditions and a large amounts of data to do the further analysis.

scholarly journals An Investigation of Local Site Effects Using Linear and Nonlinear analysis and Comparison Between Them

2016 ◽  
Vol 2 (4) ◽  
pp. 113-122 ◽  
Author(s):  
Ali Komak Panah ◽  
Aylin Nouri
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Earthquake Engineering ◽  
Shear Wave Velocity ◽  
Response Spectrum ◽  
Response Analysis ◽  
Site Classification ◽  
Ground Response Analysis ◽  
Soil Response ◽  
Design Response Spectrum

Recent code provisions for building and other structures (1994 and 1997 NEHRP provisions, 1997 UBC) have adopted new site classification. The new site classification system is based on average shear wave velocity to a depth of 30 m. when the shear wave velocity is not available; other soil properties such as undrained shear strength can be used. The study of propagation damages in various earthquakes illustrates the importance of the site effect on the ground seismic characteristics. From the point of the earthquake engineering view, the most important characteristics of the strong ground motion are amplitude, frequency content and duration. All of these properties have a significant effect on earthquake damage. The behavior of soils under cyclic loading is basically nonlinear and hysteretic. Ground response analysis is used to predict the movements of the ground and develop a design response spectrum in order to determine the dynamic stresses and strains and earthquake forces. The profile was studied by using various methods of soil response analysis and finally, the results were examined. In this paper, soil responses were examined by NERA, EERA software and the results compared with each other. Eventually, we concluded that the values obtained from the EERA are more than the value obtained from the NEERA software.

scholarly journals Seismic hazard assessment and local site effect evaluation in Hanoi, Vietnam

2017 ◽  
Vol 17 (4B) ◽  
pp. 82-95
Author(s):  
Nguyen Anh Duong ◽  
Pham Dinh Nguyen ◽  
Vu Minh Tuan ◽  
Bui Van Duan ◽  
Nguyen Thuy Linh
Keyword(s):  
Seismic Hazard ◽  
Shear Wave ◽  
Ground Motion ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Peak Ground Acceleration ◽  
Site Effect ◽  
Local Site Effect ◽  
Ground Acceleration ◽  
Local Site

In this study, we have carried out the probabilistic seismic hazard analysis in Hanoi based on the latest seismotectonic data. The seismic hazard map shows peak ground acceleration values on rock corresponding to the 10% probability of exceedance in a 50-year time period (approximately return periods of 500 years). The calculated results reveal that the maximum ground acceleration can occur on rock in Hanoi is about 0.13 g corresponding to the shaking intensity level of VIII on the MSK-64 scale. The ground motion values calculated on rock vary according to the local site conditions. We have evaluated and corrected the local site effects on ground motion in Ha Dong district, Hanoi by using microtremor and borehole data. The Nakamura’s H/V spectral ratio method has been applied to establish a map of ground dominant periods in Ha Dong with a TS range of 0.6 - 1.2 seconds. The relatively high values of periods indicate that Ha Dong has soft soil and thick Quaternary sediments. The sediment thickness in Ha Dong is calculated to vary between 30 - 75 m based on ground dominant periods and shear wave velocity VS30 = 171 - 254 m/s. The results of local site effect on ground motion show that the 500-year return period peak ground acceleration in Ha Dong ranges from 0.13 g to 0.17 g. It is once again asserted that the seismic hazard in Hanoi is a matter of great concern, due not only to the relatively high ground acceleration, but also to the seismic characteristics of soil (low shear wave velocity, ground dominant period of approximately 1 second).

scholarly journals Risks of Solely Relying on VS30 in Ground Motion Response Studies

2018 ◽  
Vol 4 (12) ◽  
pp. 2937
Author(s):  
Amin Ghanbari ◽  
Younes Daghigh ◽  
Forough Hassanvand
Keyword(s):  
Shear Wave ◽  
Ground Motion ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Ground Surface ◽  
Earthquake Excitation ◽  
Site Class ◽  
Velocity Models ◽  
Average Shear ◽  
Classification Tool

The average shear wave velocity of the uppermost 30 m of earth (Vs30) is widely used in seismic geotechnical engineering and soil-structure interaction studies. In this regard, any given subsurface profile is assigned to a specific site class according to its average shear wave velocity. However, in a real-world scenario, entirely different velocity models could be considered in the same class type due to their identical average velocities. The objective of the present study is to underline some of the risks associated with solely using Vs30 as a classification tool. To do so, three imaginary soil profiles that are quite different in nature, but all with the same average Vs were considered and were subjected to the same earthquake excitation. Seismic records acquired at the ground surface demonstrated that the three sites have different ground motion amplifications. Then, the different ground responses were used to excite a five-story structure. Results confirmed that even sites from the same class can indeed exhibit different responses under identical seismic excitations. Our results demonstrated that caution should be practiced when large-contrast velocity models are involved as such profiles are prone to pronounced ground motion amplification. This study, which serves as link between soil dynamics and structural dynamics, warns practitioners about the risks associated with oversimplifying the subsurface profile. Such oversimplifications can potentially undermine the safety of existing or future structures.

scholarly journals Struktur Kecepatan Gelombang Geser (Vs) di Daerah Rawan Gerakan Tanah (Longsor) Jalan Lintas Kabupaten Bengkulu Tengah-Kepahiang

2021 ◽  
Vol 11 (2) ◽  
pp. 134
Author(s):  
Nanang Sugianto ◽  
Refrizon Refrizon
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Velocity Structure ◽  
Soft Rock ◽  
Rock Properties ◽  
Subsurface Structure ◽  
Class D ◽  
Class B ◽  
Hard Structures

Shear wave velocity <em>(V<sub>s</sub>)</em> structure at along of Central Bengkulu-Kepahiang crossline has been mapped. This research aims to identify the subsurface structure and to estimate the constituent material type of rock in landslide-prone areas (Central Bengkulu-Kepahiang crossline). Shear wave velocity structure on each site is obtained by the HVSR-inversion of 146 microtremor data (ambient noise recording of seismometer). <em>V<sub>s</sub></em> structure at the line mapped from the surface until to 30 meters of the depth. Groups of Vs are identified in class E (<em>V<sub>s</sub></em> &lt;180), Class D (180≤<em> V<sub>s</sub></em> &lt;360), Class C (360≤<em> V<sub>s</sub></em> &lt;760), and Class B (760≤<em> V<sub>s</sub></em> &lt;1500). The subsurface structure at the depth of 0 to 10 meters are dominated by stiff soil, very dense soil, and soft rock which has highly fractured and weathered rock properties. At the depth of 15 meters to 30 meters, the subsurface structure is dominated by hard rock but it is high potential or easy to fracturing and weathering like the properties of the rocks in areas that have landslides in the past. Based on <em>V<sub>s</sub></em> value, rock constituent materials are deposition of sand, clay, gravel and alluvium ranging from soft to relatively hard structures at the depth.

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