scholarly journals Retesting of Liquefaction/Nonliquefaction Case Histories in the Imperial Valley

2005 ◽  
Vol 21 (1) ◽  
pp. 179-196 ◽  
Author(s):  
Robb E. S. Moss ◽  
Brian D. Collins ◽  
Daniel H. Whang
Keyword(s):  
Case History ◽  
Epistemic Uncertainty ◽  
Back Analysis ◽  
Case Histories ◽  
Cone Penetration ◽  
Imperial Valley ◽  
Ground Shaking ◽  
Data Points ◽  
History Database ◽  
Strong Ground

This paper describes the retesting of liquefaction and nonliquefaction field case histories in the Imperial Valley using the electric cone penetration test (CPT). Subsurface testing of the River Park and Heber Road sites first occurred following the 1979 Imperial Valley earthquake (Bennett et. al. 1981, Youd and Bennett 1983). These two sites are rich in information because they have experienced several earthquakes in recent history, have been subjected to moderate levels of strong ground shaking, the liquefiable layers have appreciable fines content, and the sites contain a number of high-quality nonliquefied data points. The recent liquefaction case history database for probabilistic assessment of liquefaction triggering by Moss et. al. (2003), is based primarily on data acquired using the modern electric cone following ASTM D5778. Case histories previously explored with a cone not adhering to current ASTM standards may introduce significant epistemic uncertainty into the assessment of liquefaction potential and are considered sub-optimal for probabilistic analysis purposes. This paper describes the acquisition and analysis of modern electric cone data at the Heber Road and River Park sites. These important sites can now be incorporated into the probabilistic CPT-based liquefaction case history database and used for back-analysis of liquefaction triggering. Discussed are the effects of ground motion character and frequency content on liquefaction at these two sites and how this influences the results using a simplified liquefaction procedure.

CPT-based liquefaction case histories compiled from three earthquakes in Canterbury, New Zealand

2021 ◽  
pp. 875529302199636
Author(s):  
Mertcan Geyin ◽  
Brett W Maurer ◽  
Brendon A Bradley ◽  
Russell A Green ◽  
Sjoerd van Ballegooy
Keyword(s):  
New Zealand ◽  
Case History ◽  
Prediction Models ◽  
Free Field ◽  
Case Histories ◽  
Cone Penetration ◽  
History Data ◽  
The Past ◽  
Surface Manifestation ◽  
The Many

Earthquakes occurring over the past decade in the Canterbury region of New Zealand have resulted in liquefaction case-history data of unprecedented quantity. This provides the profession with a unique opportunity to advance the prediction of liquefaction occurrence and consequences. Toward that end, this article presents a curated dataset containing ∼15,000 cone-penetration-test-based liquefaction case histories compiled from three earthquakes in Canterbury. The compiled, post-processed data are presented in a dense array structure, allowing researchers to easily access and analyze a wealth of information pertinent to free-field liquefaction response (i.e. triggering and surface manifestation). Research opportunities using these data include, but are not limited to, the training or testing of new and existing liquefaction-prediction models. The many methods used to obtain and process the case-history data are detailed herein, as is the structure of the compiled digital file. Finally, recommendations for analyzing the data are outlined, including nuances and limitations that users should carefully consider.

Liquefaction at Strong Motion Stations and in Urayasu City during the 2011 Tohoku-Oki Earthquake

2013 ◽  
Vol 29 (1_suppl) ◽  
pp. 55-80 ◽  
Author(s):  
Brady R. Cox ◽  
Ross W. Boulanger ◽  
Kohji Tokimatsu ◽  
Clinton M. Wood ◽  
Akio Abe ◽  
...  
Keyword(s):  
Strong Motion ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Case Histories ◽  
Cone Penetration ◽  
Penetration Testing ◽  
Cone Penetration Testing ◽  
Recent Sediments ◽  
Wave Methods ◽  
Strong Ground

The 2011 MW = 9.0 Tohoku-oki earthquake generated a large number of unique soil liquefaction case histories, including cases with strong ground motion recordings on liquefiable or potentially liquefiable soils. We have compiled a list of 22 strong motion stations (SMS) where surface evidence of liquefaction was observed and 16 SMS underlain by geologically recent sediments or fills where surface evidence of liquefaction was not observed. Pre-earthquake standard penetration test data and borehole shear wave velocity ( Vs) profiles are available for some stations, but critical information, such as grain size distribution and fines plasticity, are often lacking. In the heavily damaged city of Urayasu, we performed post-earthquake cone penetration testing at seven SMS and Vs profiles, using surface wave methods at 28 additional locations to supplement existing geotechnical data. We describe the liquefaction effects in Urayasu, the available site characterization data, and our initial data interpretations.

Liquefaction during the 1990 Manjil, Iran, earthquake, I: Case history data

1995 ◽  
Vol 85 (1) ◽  
pp. 66-82
Author(s):  
M. K. Yegian ◽  
V. G. Ghahraman ◽  
M. A. A. Nogole-Sadat ◽  
H. Daraie
Keyword(s):  
Case History ◽  
Case Histories ◽  
Ground Displacement ◽  
Liquefaction Potential ◽  
Related Case ◽  
Ground Shaking ◽  
History Data ◽  
Liquefied Soils ◽  
And Performance ◽  
Ground Liquefaction

Abstract During the 1990 Manjil, Iran, earthquake (MS = 7.7), an estimated 35,000 people lost their lives and more than 300,000 were left homeless. The earthquake ground shaking caused enormous destruction of unreinforced structures. In addition, widespread liquefaction contributed significantly to building damage in towns as far away as 85 km from the ruptured fault. Following the earthquake, the authors surveyed the liquefaction regions, conducted geotechnical field explorations, and documented case histories on liquefaction of level ground, liquefaction-induced building settlement, permanent ground displacement, and performance of piles and piers in liquefied soils. This article presents and discusses the data of the case histories investigated. In addition, based on the evidence from the Manjil earthquake, the importance of geologic input in mapping of liquefaction potential in earthquake-prone regions is demonstrated. In the companion article, the authors present the results of their analyses of liquefaction-related case histories.

Source dynamics of the 1979 Imperial Valley earthquake from near-source observations (of ground acceleration and velocity)

1982 ◽  
Vol 72 (6A) ◽  
pp. 1957-1968
Author(s):  
Mansour Niazi
Keyword(s):  
Particle Acceleration ◽  
Particle Velocity ◽  
High Frequency ◽  
Observation Point ◽  
P Wave ◽  
Imperial Valley ◽  
Ground Acceleration ◽  
Data Set ◽  
Ground Shaking ◽  
Fault Surface

abstract Two sets of observations obtained during the 15 October 1979 Imperial Valley earthquake, MS 6.9, are presented. The data suggest different dynamic characteristics of the source when viewed in different frequency bands. The first data set consists of the observed residuals of the horizontal peak ground accelerations and particle velocity from predicted values within 50 km of the fault surface. The residuals are calculated from a nonlinear regression analysis of the data (Campbell, 1981) to the following empirical relationships, PGA = A 1 ( R + C 1 ) − d 1 , PGV = A 2 ( R + C 2 ) − d 2 in which R is the closest distance to the plane of rupture. The so-calculated residuals are correlated with a positive scalar factor signifying the focusing potential at each observation point. The focusing potential is determined on the basis of the geometrical relation of the station relative to the rupture front on the fault plane. The second data set consists of the acceleration directions derived from the windowed-time histories of the horizontal ground acceleration across the El Centro Differential Array (ECDA). The horizontal peak velocity residuals and the low-pass particle acceleration directions across ECDA require the fault rupture to propagate northwestward. The horizontal peak ground acceleration residuals and the high-frequency particle acceleration directions, however, are either inconclusive or suggest an opposite direction for rupture propagation. The inconsistency can best be explained to have resulted from the incoherence of the high-frequency radiation which contributes most effectively to the registration of PGA. A test for the sensitivity of the correlation procedure to the souce location is conducted by ascribing the observed strong ground shaking to a single asperity located 12 km northwest of the hypocenter. The resulting inconsistency between the peak acceleration and velocity observations in relation to the focusing potential is accentuated. The particle velocity of Delta Station, Mexico, in either case appears abnormally high and disagrees with other observations near the southeastern end of the fault trace. From the observation of a nearly continuous counterclockwise rotation of the plane of P-wave particle motion at ECDA, the average rupture velocity during the first several seconds of source activation is estimated to be 2.0 to 3.0 km/sec. A 3 km upper bound estimate of barrier dimensions is tentatively made on the basis of the observed quasiperiodic variation of the polarization angles.

Nonlinear behavior of soil sediments identified by using borehole records observed at the Ashigra Valley, Japan

1995 ◽  
Vol 85 (6) ◽  
pp. 1821-1834
Author(s):  
Toshimi Satoh ◽  
Toshiaki Sato ◽  
Hiroshi Kawase
Keyword(s):  
Shear Strain ◽  
Main Part ◽  
Nonlinear Behavior ◽  
Strong Motion ◽  
S Wave ◽  
Ground Shaking ◽  
Wave Velocities ◽  
The One ◽  
Soil Sediments ◽  
Strong Ground

Abstract We evaluate the nonlinear behavior of soil sediments during strong ground shaking based on the identification of their S-wave velocities and damping factors for both the weak and strong motions observed on the surface and in a borehole at Kuno in the Ashigara Valley, Japan. First we calculate spectral ratios between the surface station KS2 and the borehole station KD2 at 97.6 m below the surface for the main part of weak and strong motions. The predominant period for the strong motion is apparently longer than those for the weak motions. This fact suggests the nonlinearity of soil during the strong ground shaking. To quantify the nonlinear behavior of soil sediments, we identify their S-wave velocities and damping factors by minimizing the residual between the observed spectral ratio and the theoretical amplification factor calculated from the one-dimensional wave propagation theory. The S-wave velocity and the damping factor h (≈(2Q)−1) of the surface alluvial layer identified from the main part of the strong motion are about 10% smaller and 50% greater, respectively, than those identified from weak motions. The relationships between the effective shear strain (=65% of the maximum shear strain) calculated from the one-dimensional wave propagation theory and the shear modulus reduction ratios or the damping factors estimated by the identification method agree well with the laboratory test results. We also confirm that the soil model identified from a weak motion overestimates the observed strong motion at KS2, while that identified from the strong motion reproduces the observed. Thus, we conclude that the main part of the strong motion, whose maximum acceleration at KS2 is 220 cm/sec2 and whose duration is 3 sec, has the potential of making the surface soil nonlinear at an effective shear strain on the order of 0.1%. The S-wave velocity in the surface alluvial layer identified from the part just after the main part of the strong motion is close to that identified from weak motions. This result suggests that the shear modulus recovers quickly as the shear strain level decreases.

scholarly journals Earthquakes on the surface: earthquake location and area based on more than 14 500 ShakeMaps

2018 ◽  
Vol 18 (6) ◽  
pp. 1665-1679
Author(s):  
Stephanie Lackner
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Earthquake Location ◽  
Primary Concern ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Geographic Context ◽  
The Social ◽  
Strong Ground

Abstract. Earthquake impact is an inherently interdisciplinary topic that receives attention from many disciplines. The natural hazard of strong ground motion is the reason why earthquakes are of interest to more than just seismologists. However, earthquake shaking data often receive too little attention by the general public and impact research in the social sciences. The vocabulary used to discuss earthquakes has mostly evolved within and for the discipline of seismology. Discussions on earthquakes outside of seismology thus often use suboptimal concepts that are not of primary concern. This study provides new theoretic concepts as well as novel quantitative data analysis based on shaking data. A dataset of relevant global earthquake ground shaking from 1960 to 2016 based on USGS ShakeMap data has been constructed and applied to the determination of past ground shaking worldwide. Two new definitions of earthquake location (the shaking center and the shaking centroid) based on ground motion parameters are introduced and compared to the epicenter. These definitions are intended to facilitate a translation of the concept of earthquake location from a seismology context to a geographic context. Furthermore, the first global quantitative analysis on the size of the area that is on average exposed to strong ground motion – measured by peak ground acceleration (PGA) – is provided.

scholarly journals The Role of Seismological Networks in Civil Protection in Low and High Seismic Hazards

2021 ◽  
Author(s):  
Erzsébet Győri ◽  
Arman Bulatovich Kussainov ◽  
Gyöngyvér Szanyi ◽  
Zoltán Gráczer ◽  
Kendebay Zhanabilovich Raimbekov ◽  
...  
Keyword(s):  
Early Warning ◽  
Early Warning Systems ◽  
Economic Losses ◽  
Civil Protection ◽  
Warning Systems ◽  
Ground Shaking ◽  
Research Areas ◽  
Seismic Networks ◽  
Strong Ground

Earthquakes are one of the most devastating natural disasters on Earth, causing sometimes huge economic losses and many human casualties. Since earthquake prediction is not yet possible, the purpose of civil protection is to reduce damage and protect human lives, in which the seismological networks of different countries play a very important role. Special applications of seismic networks are the early warning systems that can be used to protect vulnerable infrastructures using automated shutdown procedures, to stop high velocity trains and to save lives if the general public is notified about imminent strong ground shaking. In this paper, we describe the aims and operation of seismological networks, covering in more detail the early warning systems. Then we delineate the seismotectonic settings and seismicity in Hungary and Kazakhstan, furthermore, describe the operating seismological networks and the related scientific research areas with emphasis on civil protection. Hungary and Kazakhstan differ not only in the size of their territory, but also in their seismicity, therefore, in addition to the similarities, there are also significant differences between the aims and problems of their seismological networks.

The island of Hawaii earthquakes of November 29, 1975: Strong-motion data and damage reconnaissance report

1977 ◽  
Vol 67 (2) ◽  
pp. 493-515
Author(s):  
Christopher Rojahn ◽  
B. J. Morrill
Keyword(s):  
Local Time ◽  
Structural Damage ◽  
Strong Motion ◽  
Maximum Acceleration ◽  
Epicentral Area ◽  
Ground Shaking ◽  
Motion Data ◽  
Large Sector ◽  
Threshold Duration ◽  
Strong Ground

Abstract Two earthquakes occurred on the island of Hawaii on November 29, 1975, a magnitude (Ms) 5.7 event at 0335 (local time) and a magnitude (Ms) 7.2 event at 0447. During the larger event, a maximum acceleration of 0.22 g was recorded in the southern part of Hilo, 43 km north of the epicenter. A 0.05 g threshold duration of 13.7 sec was measured for the same component. Smaller amplitude accelerograph records were obtained at two other locations on the island along with four seismoscope records. During or subsequent to the larger event, a large sector of the southeastern coastline subsided by as much as 3.5 meters. A tsunami generated by the larger event caused at least one death (one person also missing), injury to 28 persons, and significant structural and nonstructural damage. Only scattered evidence of strong ground shaking was observed in the epicentral area, and most of the several dozen nearby structures sustained little or no structural damage from ground shaking. In Hilo, 45 km north of the Ms = 7.2 epicenter, structural and nonstructural damage was slight to moderate but more extensive than elsewhere on the island.

Duration of nuclear explosion ground motion

1978 ◽  
Vol 68 (4) ◽  
pp. 1133-1145
Author(s):  
Walter W. Hays ◽  
Kenneth W. King ◽  
Robert B. Park
Keyword(s):  
Epicentral Distance ◽  
Ground Motions ◽  
Broad Band ◽  
Time History ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Distance Range ◽  
Nuclear Explosions ◽  
Dependent Site ◽  
Strong Ground

abstract This paper evaluates the duration of strong ground shaking that results from nuclear explosions and identifies some of the problems associated with its determination. Knowledge of the duration of horizontal ground shaking is important out to epicentral distances of about 44 km and 135 km, the approximate distances at which the ground shaking level falls to 0.01 g for nuclear explosions having yields of about 100 kt and 1,000 kt, respectively. Evaluation of the strong ground motions recorded from the event STRAIT (ML = 5.6) on a linear array of five, broad-band velocity seismographs deployed in the distance range 3.2 to 19.5 km provides information about the characteristics of the duration of ground shaking. The STRAIT data show that: (1) the definition that is used for defining duration is very important; (2) the duration of ground acceleration, as defined in terms of 90 per cent of the integral of the squared time history (Trifunac and Brady, 1975), increased from about 4 to 26 sec over the approximately 20-km distance range; and (3) the duration of ground velocity and displacement were slightly greater because of the effect of the alluvium layer on the propagating surface waves. Data from other events (e.g., MILROW, CANNIKIN, HANDLEY, PURSE) augment the STRAIT data and show that: (1) duration of shaking is increased by frequency-dependent site effects and (2) duration of shaking, as defined by the integral of the squared time history, does not increase as rapidly with increase in yield as is indicated by other definitions of duration that are stated in terms of an amplitude threshold (e.g., bracketed duration, response envelopes). The available data suggest that the duration of ground acceleration, based on the integral definition, varies from about 4 to 40 sec for a 100-kt range explosion and from about 4 to 105 sec for a megaton range explosion in the epicentral distance range of 0 to 44 km and 0 to 135 km, respectively.

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