Performance of a Rigid Frame Arch Bridge under Near-Fault Earthquake Ground Motion

2011 ◽  
Vol 250-253 ◽  
pp. 1869-1872 ◽  
Author(s):  
Yong Huang ◽  
Jun Jie Wang ◽  
De Yin Jin
Keyword(s):  
Wenchuan Earthquake ◽  
Ground Motion ◽  
Strong Ground Motion ◽  
Earthquake Ground Motion ◽  
Weak Links ◽  
Response Analysis ◽  
Arch Bridge ◽  
2008 Wenchuan Earthquake ◽  
Rigid Frame ◽  
Strong Ground

During May 12th 2008 Wenchuan earthquake with the magnitude of 8.0, a 4-span rigid frame arch bridge named as Xiaoyudong Bridge which situated close to the epicenter was hit by strong ground motion and was severely damaged. The earthquake response analysis of the bridge was made using FE software MIDAS based on recorded ground motion during the Wenchuan earthquake in this paper. The study showed that the main and minor arch legs on the both ends piers were weak links which may be damaged firstly under strong ground motion. The next damage at the pier with weakest horizontal stiffness is one of the important reasons causing the bridge collapsed. This paper will introduce our work on those respects and some drawn conclusions.

The Loma Prieta earthquake, ground motion, and damage in Oakland, Treasure Island, and San Francisco

1991 ◽  
Vol 81 (5) ◽  
pp. 2019-2047
Author(s):  
Thomas C. Hanks ◽  
A. Gerald Brady
Keyword(s):  
Ground Motion ◽  
San Francisco ◽  
Strong Ground Motion ◽  
Strong Motion ◽  
Earthquake Ground Motion ◽  
Transverse Motion ◽  
Loma Prieta Earthquake ◽  
Loma Prieta ◽  
Treasure Island ◽  
Strong Ground

Abstract The basis of this study is the acceleration, velocity, and displacement wave-forms of the Loma Prieta earthquake (18 October 1989; M = 7.0) at two rock sites in San Francisco, a rock site on Yerba Buena Island, an artificial-fill site on Treasure Island, and three sites in Oakland underlain by thick sections of poorly consolidated Pleistocene sediments. The waveforms at the three rock sites display a strong coherence, as do the three sedimentary sites in Oakland. The duration of strong motion at the rock sites is very brief, suggestive of an unusually short source duration for an earthquake of this size, while the records in Oakland show strong amplification effects due to site geology. The S-wave group at Treasure Island is phase coherent with the Oakland records, but at somewhat diminished amplitudes, until the steps in acceleration at approximately 15 sec, apparently signaling the onset of liquefaction. All seven records clearly show shear-wave first motion opposite to that expected for the mainshock radiation pattern and peak amplitudes greater than expected for sites at these distances (95 ± 3 km) from an earthquake of this magnitude. While the association between these ground motion records and related damage patterns in nearby areas has been easily and eagerly accepted by seismological and engineering observers of them, we have had some difficulty in making such relationships quantitative or even just clear. The three Oakland records, from sites that form a nearly equilateral triangle about the Cypress Street viaduct collapse, are dominated by a long-period resonance (≃ 1 1/2-sec period) far removed from the natural frequency of the structure to transverse motion (2.5 Hz) or from high-frequency amplification bands observed in aftershock studies. A spectral ratio arbiter of this discrepancy confuses it further. The failure of the East Bay crossing of the San Francisco-Oakland Bay Bridge cannot be attributed to relative displacements of the abutments in Oakland and Yerba Buena Island, but the motions of the Bay Bridge causing failure remain unknown. The steps in acceleration at Treasure Island present unusual strong-motion accelerogram processing problems, and modeling suggests that the velocity and displacement waveforms are contaminated by a spurious response of the filtering operations to the acceleration steps. A variety of coincidences suggests that the Treasure island accelerogram is the most likely strong-motion surrogate for the filled areas of the Marina District, for which no mainshock records are available, but the relative contributions of bad ground, poor construction and truly strong ground motion to damage in the Marina District will never by known in any quantitative way. The principal lesson of all of this is that until a concerted effort is mounted to instrument ground and structures that are likely to fail during earthquakes, our understanding of the very complex relationships between strong ground motion and earthquake damage will, in general, remain rudimentary, imprecise, and vague.

scholarly journals Rupture directivity effect on strong ground motion during the 12 May 2008 MW7.9 Wenchuan earthquake

2021 ◽  
Vol 34 (0) ◽  
pp. 1-16
Author(s):  
Zhao An ◽  
◽  
Jun-Ju Xie ◽  
Yong Zhang ◽  
Xiao-Jun Li ◽  
...  
Keyword(s):  
Wenchuan Earthquake ◽  
Ground Motion ◽  
Strong Ground Motion ◽  
Rupture Directivity ◽  
Directivity Effect ◽  
Strong Ground

scholarly journals ESTIMATION OF SUBSURFACE STRUCTURE BASED ON MICROTREMOR, BORE HOLE OBSERVATIONS AND STOCHASTIC STRONG GROUND MOTION SIMULATIONS IN PALU CITY, CENTRAL SULAWESI, INDONESIA: A VALIDATION AND SENSITIVITY STUDY ON THE 23 JANUARY 2005 (PALU) EARTHQUAKE

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Pyi Soe Thein ◽  
Subagyo Pramumijoyo ◽  
Wahyu Wilopo ◽  
Agung Setianto ◽  
Kirbani Sri Brotopuspito ◽  
...  
Keyword(s):  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Strong Ground Motion ◽  
Soil Condition ◽  
Fault System ◽  
Earthquake Ground Motion ◽  
Subsurface Structure ◽  
Ground Acceleration ◽  
Central Sulawesi ◽  
Strong Ground

In this study, we investigated the subsurface structure and strong ground motion parameters for Palu City. One of the major structures in Central Sulawesi is the Palu-Koro Fault system. Several powerful earthquakes have struck along the Palu-Koro Fault during recent years, one of the largest of which was an M 6.3 event that occurred on January 23, 2005 and caused several casualties. Following the event, we conducted a microtremor survey to estimate the shaking intensity distribution during the earthquake. From this survey we produced a map of the peak ground acceleration, velocity and ground shear strain in Palu City. We performed single observations of microtremors at 151 sites in Palu City. The results enabled us to estimate the site-dependent shaking characteristics of earthquake ground motion. We also conducted 8-site microtremor array investigation to gain a representative determination of the soil condition of subsurface structures in Palu. From the dispersion curve of array observations, the central business district of Palu corresponds to relatively soil condition with Vs ≤ 300 m/s, the predominant periods due to horizontal vertical ratios (HVSRs) are in the range of 0.4 to 1.8 s and the resonant frequency are in the range of 0.7 to 3.3 Hz. Three boreholes were throughout the basin especially in Palu area to evaluate the geotechnical properties of subsurface soil layers. The depths are varying from 1 m to 30 m. Strong ground motions of the Palu area were predicted based on the empirical stochastic green’s function method. Peak ground acceleration and peak ground velocity becomes more than 0.04 g and 30 kine in some areas, which causes severe damage for buildings in high probability. Keywords: Palu-Koro fault, microtremor, bore holes, peak ground acceleration and velocity.

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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