Predicting the near-field strong ground motion based on uncertainties in asperities: an opportunity to reproduce the characteristics of the 1970 Tonghai earthquake (Ms 7.8)

2021 ◽  
Author(s):  
Zongchao Li ◽  
Jize Sun ◽  
Xueliang Chen ◽  
Guochen Wang ◽  
Qingfeng Ding
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Near Field ◽  
Strong Ground

scholarly journals Near-Field Ground Motion Modal versus Wave Propagation Analysis

2010 ◽  
Vol 17 (4-5) ◽  
pp. 611-617 ◽  
Author(s):  
Artur Cichowicz
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Response Spectrum ◽  
Near Field ◽  
Spectral Characteristics ◽  
Beam Model ◽  
Drift Spectrum ◽  
Localized Deformation ◽  
Dominant Period ◽  
Strong Ground

The response spectrum generally provides a good estimate of the global displacement and acceleration demand of far-field ground motion on a structure. However, it does not provide accurate information on the local shape or internal deformation of the response of the structure. Near-field pulse-like ground motion will propagate through the structure as waves, causing large, localized deformation. Therefore, the response spectrum alone is not a sufficient representation of near-field ground motion features. Results show that the drift-response technique based on a continuous shear-beam model has to be employed here to estimate structure-demand parameters when structure is exposed to the pulse like ground motion. Conduced modeling shows limited applicability of the drift spectrum based on the SDOF approximation. The SDOF drift spectrum approximation can only be applied to structures with smaller natural periods than the dominant period of the ground motion. For periods larger than the dominant period of ground motion the SDOF drift spectra model significantly underestimates maximum deformation. Strong pulse-type motions are observed in the near-source region of large earthquakes; however, there is a lack of waveforms collected from small earthquakes at very close distances that were recorded underground in mines. The results presented in this paper are relevant for structures with a height of a few meters, placed in an underground excavation. The strong ground motion sensors recorded mine-induced earthquakes in a deep gold mine, South Africa. The strongest monitored horizontal ground motion was caused by an event of magnitude 2 at a distance of 90 m with PGA 123 m/s2, causing drifts of 0.25%–0.35%. The weak underground motion has spectral characteristics similar to the strong ground motion observed on the earth's surface; the drift spectrum has a maximum value less than 0.02%.

An Improved Source Model for Simulation Near-Field Strong Ground Motion Acceleration Time History

2013 ◽  
Vol 438-439 ◽  
pp. 1474-1480
Author(s):  
Ju Fang Zhong ◽  
Long Wei Zhang ◽  
Jun Wei Liang
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Response Spectrum ◽  
Near Field ◽  
Time History ◽  
Source Spectrum ◽  
Acceleration Time ◽  
Acceleration Time History ◽  
Spectrum Model ◽  
Strong Ground

The key to near-field strong ground motion simulation based on stochastic finite fault method is to determine the spectrum of ground motion. We present an improved source spectrum model for simulation near-field strong ground motion acceleration time history. We combine Masudas source spectrum model with scaling factor Hij to keep radiation energy conservation and reflect the energy decrease with frequency at low to mid frequencies. We calculate the Fourier amplitude spectrum Fa, accelerate response spectrum Sa, velocity response spectrum Sv and displacement response spectrum Sd of simulation time histories. By comparative analysis of the laws of spectrum values (Fa, Sa, Sv, Sd) with the variation of frequency or period, we discusses the effects of sub-fault dividing scheme, the method of determining scale factor and source spectrum model on spectrum values (Fa, Sa, Sv, Sd). The results show that sub-fault dividing scheme has slightly effect on the model presented in this paper, and the model enable to reflect the sink laws of source spectrum value in mid-to-low frequencies well. We demonstrate that the improved model is superior to other commonly used models.

A method for synthesizing realistic strong ground motion

1971 ◽  
Vol 61 (6) ◽  
pp. 1739-1753 ◽  
Author(s):  
Mihailo D. Trifunac
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Group Velocity Dispersion ◽  
Near Field ◽  
New Method ◽  
Release Mechanism ◽  
Low Velocity ◽  
Local Geology ◽  
Artificial Accelerograms ◽  
Strong Ground

abstract A new method of synthesizing artificial accelerograms, based on knowledge of the temporal and spatial properties of the energy-release mechanism, incorporates the effects of local geology through theoretical group-velocity dispersion data for a given site. It is assumed that most of the near-field strong ground motion caused by shallow or surface faulting or explosions is represented by energy propagating through the low-velocity surface-wave guide. The new method of generating artificial accelerograms realistically models strong ground motion for applied structural analysis and theoretical investigations of the response of hysteretic-type structures, soil-structure interaction, and statistics of failure.

scholarly journals Strong ground motion prediction for southwestern China from small earthquake records

2015 ◽  
Vol 3 (9) ◽  
pp. 5297-5323
Author(s):  
Z. R. Tao ◽  
X. X. Tao ◽  
A. P. Cui
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Near Field ◽  
Seismic Hazard Assessment ◽  
Southwestern China ◽  
Small Earthquake ◽  
Earthquake Records ◽  
Strong Ground Motion Prediction ◽  
Ground Motion Records ◽  
Strong Ground

Abstract. For regions lack of strong ground motion records, a method is developed to predict strong ground motion by small earthquake records from local broadband digital earthquake networks. Sichuan and Yunnan regions, located in southwestern China, are selected as the targets. Five regional source and crustal medium parameters are inversed by micro-Genetic Algorithm. These parameters are adopted to predict strong ground motion for moment magnitude (Mw) 5.0, 6.0 and 7.0. Strong ground motion data are compared with the results, most of the result pass through ideally the data point plexus, except the case of Mw 7.0 in Sichuan region, which shows an obvious slow attenuation. For further application, this result is adopted in probability seismic hazard assessment (PSHA) and near-field strong ground motion synthesis of the Wenchuan Earthquake.

Sensitivity analysis study of the source parameter uncertainty factors for predicting near-field strong ground motion

2018 ◽  
Vol 66 (4) ◽  
pp. 523-540 ◽  
Author(s):  
Zongchao Li ◽  
Mengtan Gao ◽  
Han Jiang ◽  
Xueliang Chen ◽  
Tiefei Li ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Ground Motion ◽  
Parameter Uncertainty ◽  
Strong Ground Motion ◽  
Near Field ◽  
Source Parameter ◽  
Uncertainty Factors ◽  
Analysis Study ◽  
Strong Ground

Identification of Near-Field Pulse-Like Ground Motions Recorded at Bajiao Station during the Mainshock of the Great Wenchuan Earthquake

2011 ◽  
Vol 250-253 ◽  
pp. 2546-2553 ◽  
Author(s):  
Chun Feng Li ◽  
Yong Bo Li
Keyword(s):  
Wenchuan Earthquake ◽  
Ground Motion ◽  
Strong Ground Motion ◽  
Ground Motions ◽  
Near Field ◽  
Velocity Pulse ◽  
Field Pulse ◽  
Near Fault ◽  
Ground Motion Records ◽  
Strong Ground

When earthquake occurs, it is in near-fault that the most serious damage happens and velocity pulse appears. Velocity pulse could have huge potential to destroy the structure in near-fault. The set of records at Bajiao Station is one of the three famous near-field sets of strong ground motion records whose PGAs are the largest in all the sets of records obtained from the mainshock of the Great Wenchuan Earthquake. Our research is to identify the pulse-like characteristics from the set of records at Bajiao Station. It is found that velocity pulses in the records are “hidden pulses”.

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