Comparison of the cumulative absolute velocity and acceleration peak value based on Wenchuan earthquake data

This paper discusses and presents the cumulative absolute velocity （CAV） parameters of the Wenchuan earthquake. Additionally, the CAV calculated from recorded data for the earthquake is compared to the peak ground acceleration（PGA）, based on a brief analysis of background information. Accordingly, the paper studied the relationship between the CAV and PGA, and 3 CAV/PGA ratio charts were obtained in three different sub-directions. Linear and polynomial fitting operations were then used to analyze the potential discipline and characteristics in these directions. Finally, in the study, we investigated the applicability of using the CAV parameter for earthquake observation systems, and the CAV parameter was paired with the currently used PGA to provide earthquake observers and emergency responders with a theoretical basis.

Estimation of peak relative velocity and peak absolute acceleration of linear SDOF systems

We have found some mistakes in the article by Jianwei Song et al. （2007）. The revisions are given below：

A new empirical equation of shear wave velocity to predict the different peak surface accelerations for Jakarta city

Site condition and bedrock depth play important roles in the determination of peak surface acceleration(PSA)values by earthquake motions.The soil parameters of shear wave velocity(Vs)and standard penetration test-number(N)value for Jakarta city are available up to 100 m below the Earth’s surface even though the typical depths to bedrock are in excess of 100 m.This study referred to the base motion peak ground acceleration(PGA)values of 0.100 g,0.218 g and 0.378 g to predict the PSA values using the Nonlinear Earthquake site Response Analysis(NERA)to analyse a simulated dataset for the bedrock depths of 100 m,200 m,300 m,400 m and 500 m with conditioned by clayey and sandy soils.A new empirical equation of Vs=102.48 N0.297(m/s)was proposed to calculate the values of Vsused as an input parameter in the NERA programme for the prediction of seismic wave propagation.The results showed that the PSA values are dependent on the amplitude of seismic waves,depths of bedrock and the local site conditions.Changes in the PSA values from 41.0%to 51.5%and from 46.1%to 79.8%for the bedrocks overlain by sand,from 20.0%to 42.1%and from 45.9%to 58.8%for the bedrocks overlain by clay with increasing of bedrock depths from 200 m to 300 m and from 400 m to 500 m,respectively,were predicted for a 2500-year return period earthquake.Decreases in the PSA values by 41.0%,51.5%,46.1%,79.8%for the bedrocks overlain by sand and by 20.0%,42.1%,45.9%,58.8%for the bedrocks overlain by clay were predicted for a 2500-year return period earthquake due to the bedrock depth changes of 200 m,300 m,400 m,500 m.Large-magnitude earthquake of Jakarta city has a significant effect on an increase or a decrease of the PSA value with depth of bedrock and may cause the vibration damage to buildings and other constructions on the ground.The analysis of the PSA value and PSA ratio influenced by the PGA value,bedrock depth and local soil conditions will make a contribution to the design of earthquake-safe building for Jakarta city in the future.

Attenuation of peak ground accelerations from the great Wenchuan earthquake

Over 800 accelerograms recorded by 272 ground-level stations during the Wenchuan earthquake are used to analyze the influence of rupture distance, local site conditions and azimuth on peak ground accelerations （PGAs）. To achieve a better understanding of the characteristics of ground motions, the spatial distributions of the EW, NS and UD components of PGAs are obtained. Comparisons between the EW and NS components, the fault-normal and fault-parallel components, and the vertical and horizontal components of PGAs are performed, and the regression formula of the vertical-to-horizontal ratio of PGAs is developed. The attenuation relationship of peak horizontal accelerations （PHAs） is compared with several contemporary attenuation relationships. In addition, an analysis of residuals is conducted to identify the potential effects of rupture distance, azimuth and site conditions on the observed values of PHAs. The analysis focuses on medium-hard soil site conditions, as they provided most of the data used in this study.

Probabilistic seismic hazard assessment of Kazakhstan and Almaty city in peak ground accelerations

As for many post-soviet countries, Kazakhstan’s building code for seismic design was based on a deterministic approach. Recently, Kazakhstan seismologists are engaged to adapt the PSHA(probabilistic hazard assessment) procedure to the large amount of available geological, geophysical and tectonic Kazakh data and to meet standard requirements for the Eurocode 8. The new procedure has been used within National projects to develop the Probabilistic GSZ(General Seismic Zoning) maps of the Kazakhstan territory and the SMZ(Probabilistic Seismic Microzoning) maps of Almaty city. They agree with the seismic design principles of Eurocode 8 and are expressed in terms of not only seismic intensity,but also engineering parameters(peak ground acceleration PGA). The whole packet of maps has been developed by the Institute of Seismology, together with other Kazakhstan Institutions. Our group was responsible for making analysis in PGA. The GSZ maps and hazard assessment maps for SMZ in terms of PGA for return periods 475 and 2475 years are considered in the article.

Artificial ground motion compatible with specified peak velocity and target spectrum

In this paper, a method, which synthesizes the artificial ground motion compatible with the specified peak velocity as well as the target acceleration response spectrum, was proposed. In this method, firstly, an initial acceleration time history α8^（0） （t）, which satisfies the prescribed peak ground acceleration, the target spectral acceleration ST（ω, ζ）,and the specified intensity envelope, is generated by the traditional method that generates the requency domain; secondly,α8^（0） （t）is further modulated by superimposing narrow-band time histories upon it in the time domain to make its peak velocity, approach the target peak ground velocity, and at the same time to improve its fitting precision to the target spectrum. Numerical examples show that this algorithm boasts high calculation precisions.

Prediction of peak ground acceleration of Iran's tectonic regions using a hybrid soft computing technique

A new model is derived to predict the peak ground acceleration（PGA） utilizing a hybrid method coupling artificial neural network（ANN） and simulated annealing（SA）, called SA-ANN. The proposed model relates PGA to earthquake source to site distance, earthquake magnitude, average shear-wave velocity,faulting mechanisms, and focal depth. A database of strong ground-motion recordings of 36 earthquakes,which happened in Iran’s tectonic regions, is used to establish the model. For more validity verification,the SA-ANN model is employed to predict the PGA of a part of the database beyond the training data domain. The proposed SA-ANN model is compared with the simple ANN in addition to 10 well-known models proposed in the literature. The proposed model performance is superior to the single ANN and other existing attenuation models. The SA-ANN model is highly correlated to the actual records（R=0.835 and r =0.0908） and it is subsequently converted into a tractable design equation.

Relationship between Modified Mercalli Intensity and peak ground acceleration in Myanmar

In this study, the previously reported isoseismal maps are compiled and used to carefully investigate the macroseismic intensity in terms of the Modified Mercalli Intensity (MMI) scale, based on the engineering ground-motion parameter, as the peak ground acceleration (PGA), inferred from the ground-motion attenuation characteristic of Myanmar. The preliminary relationship between the MMI and PGA is reported to be a function of log10(PGA) = 0.2526MMI – 3.1006. The strongly correlated MMI-PGA relationship obtained in this study, if confirmed, will be particularly useful in real-time applications for damage prediction or engineering parameter determination when an earthquake occurs in or nearby to Myanmar. Compared with the previously proposed MMI-PGA relationships for other regions, the standard of building construction in Myanmar is not high enough to withstand the hazards from earthquakes, particularly at higher levels of ground motion. Therefore, the standard building code for Myanmar should be modified in order to reduce future hazards arising from earthquakes.

Amplification Effect of Peak Ground Motion Acceleration in ClassⅡ and Ⅲ Sites over Shandong Province

In this paper, the amplification factor （ks ） of peek ground motion with different exceedance probability in class Ⅱ and Ⅲ sites over Shandong Province was estimated by analyzing the seismic response data of soil layers collected from 358 boreholes of class Ⅱ sites and 140 boreholes of class Ⅲ site. From the results, one can conclude that： （1） The scatter plot of ks generally obeys a normal distribution ; （2） ks decreases with the increase of the strength of input ground motion, which is more apparent in Class Ⅲ site than in class lI site; （3） for class Ⅱ site, with the increase of depth of the bedrock interface where ground motion inputs, ks increases gradually until to a stable value when the depth reaches up to approximately 20 meters or larger. Yet, for class Ⅲ site, ks is insensitive to the depth; （4） the average of ks for class Ⅱ site is 1.47, slightly larger than that used in the Seismic Ground Motion Parameters Zonation Map of China （ GB 18306-2001 ）. Also, ks in class Ⅱ and Ⅲ sites at different levels of peak ground acceleration over Shandong Province is preliminarily discussed in the paper.

Trans-Thoracic Echocardiographic Aortic Blood Flow Peak Velocity Variation, Distance Minute, Aortic Velocity Time Integral and Postoperative Outcome in Pediatric Surgical Patients—An Observational Pilot Study Protocol

Background: A Randomized Controlled Trial (RCT) has been elaborated where goal directed fluid and hemodynamic therapy (GDFHT) will be realized with trans-thoracic echocardiographic aortic blood flow peak velocity variation (ΔVpeak) and distance minute (DM) to guide fluid therapy and hemodynamics in high risk pediatric surgical patients. This RCT will clarify the impact of GDFHT with ΔVpeak and DM on postoperative outcome in terms of morbidity, length of stay in the intensive care unit (LOSICU), length of mechanical ventilation (LMV) and length of hospital stay (LOS) in children. To determine values of ΔVpeak, DM and VTI predictive of these postoperative outcomes, an observational pilot study will be realized. This pilot study is described here. The primary objective of this study is to determine values of ΔVpeak, DM and ITV predictive of postoperative outcome in children in terms of morbidity. The secondary objectives are to determine values of ΔVpeak, DM and ITV predictive of LOSICU, LMV, LOS, intraoperative, postoperative fluid administration and vasoactive-inotropic therapy. Methods: 500 - 1000 children aged less than 18 years will be included prospectively. Statistic analysis will be realized with XLSTAT 2019.4.2 software or plus. Results and Conclusions: This trial protocol will determine values of ΔVpeak, DM and ITV with echocardiography predictive of postoperative outcome in children.

Estimation of seismic stress drop from the peak velocity of ground motion

According to the source dislocation model suggested by Brune(1970), the authors have calculated the displacement spectra of S wave and source parameters of the Heqing M S 5 3 earthquake sequence, using the digital data of this sequence obtained in the Western Yunnan Earthquake Prediction Experimental Field (WYEPEF). Based on this calculation we have studied the dependence of the peak velocity ( rv ) of ground motion on the seismic stress drop Δ σ . From the seismic scaling law we obtained ( rv )∝Δ σ 2/3 , thus the three formulae of calculating seismic stress drop Δ σ using the peak velocity parameters can be derived: lg( rv)=d 1+13lg M 0+23lgΔ σ ; lg( rv) =d 2+13 M L+23lgΔ σ ; lgΔ σ =-1 0+1 5lg( rv ) Assuming that the average stress drop Δ σ =3.0×10 6 Pa for great and small earthquakes, then the constants d 1=-3 88 and d 2=-0 38 are determined by the observational data of the Heqing M S5 3 sequence. Results of the source parameters for this sequence show that the seismic moment M 0 is between 10 11 N·m and 10 15 N·m, the rupture radius a of the source is between 200 m and 600 m, the stress drop Δ σ is between 0 1 MPa and 10 MPa and the average stress drop Δ σ =3 7 MPa calculated from the peak velocity parameter of the ground motion. Δσ values measured from these scaling relations are basically in agreement with the results given by Brune′s method( 1970). Results of this study show that the dependence of the ground motion peak velocity parameter (rv) on the stress drop Δσ is even stronger than that on the seismic moment M 0 .

The Attenuation Law of Horizontal Peak Acceleration on the Rock Site in Yunnan Area

In this paper,we select 131 accelerograms observed in the Yunnan area and cite 114 accelerograms from western America.By statistical regression analysis,we get two separate acceleration attenuation formulations based on the data of Yunnan and those of both Yunnan and western America.By analyzing and comparing the above results with the result deprived from intensity-earthquake ground motion,this paper proposes the formula below,which may show the acceleration attenuation feature of the Yunnan area:Ap=1291.07e0.5275Ms(R+15)-t.

A Bayesian Approach to Seismic Hazard Estmation: Maximum Values of Magnitudes and Peak Ground Accelerations

A rather simple straightforward procedure of estimating maximum values of the considered parameter (earthquake magnitude in a given region or seismic peak ground acceleration at the considered site) and quantiles of its probabilistic distribution in a future time interval of a given length is presented. To assess the peak ground acceleration using this method, the input information is the earthquake catalog and the regressive relation where the peak seismic acceleration at a given point bears the magnitude and epicentral distance of the site considered (seismic attenuation law). The method is based on the Bayesian approach, in which the influence of uncertainties of magnitudes and seismic acceleration values can be taken into account. The main assumptions for the method are the Poissonian character of the seismic event flow, a frequency-magnitude law of Gutenberg-Richter’s type with a cutoff maximum value for the estimated parameter, and an earthquake catalog that has a rather large number of events. The method has been applied to seismic hazard estimation in California, the Balkans, and Japan.

Feasibility of the 2-point method to determine the load-velocity relationship variables during the countermovement jump exercise

Purpose:This study aimed to examine the reliability and validity of load-velocity(L-V)relationship variables obtained through the 2-point method using different load combinations and velocity variables.Methods:Twenty men performed 2 identical sessions consisting of 2 countermovement jumps against 4 external loads(20 kg,40 kg,60 kg,and80 kg)and a heavy squat against a load linked to a mean velocity(MV)of 0.55 m/s(load_(0.55)).The L-V relationship variables(load-axis intercept(L_(0)),velocity-axis intercept(v_(0)),and area under the L-V relationship line(A_(line)))were obtained using 3 velocity variables(MV,mean propulsive velocity(MPV),and peak velocity)by the multiple-point method including(20-40-60-80-load_(0.55))and excluding(20-40-60-80)the heavy squat,as well as from their respective 2-point methods(20-load_(0.55)and 20-80).Results:The L-V relationship variables were obtained with an acceptable reliability(coefncient of variation(CV)≤7.30%;intra-class correlation coefficient>0.63).The reliability of L_(0)and v_(0)was comparable for both methods(CV_(ratio)(calculated as higher value/lower value):1.11-1.12),but the multiple-point method provided Al_(ine)with a greater reliability(CV_(ratio)=1.26).The use of a heavy squat provided the L-V relationship variables with a comparable or higher reliability than the use of a heavy countermovement jump load(CV_(ratio):1.06-1.19).The peak velocity provided the load-velocity relationship variables with the greatest reliability(CV_(ratio):1.15-1.86)followed by the MV(CV_(ratio):1.07-1.18),and finally the MPV.The 2-point methods only revealed an acceptable validity for the MV and MPV(effect size≤0.19;Pearson s product-moment correlation coefficient≥0.96;Lin's concordance correlation coefficient≥0.94).Conclusion:The 2-point method obtained from a heavy squat load and MV or MPV is a quick,safe,and reliable procedure to evaluate the lower-body maximal neuromuscular capacities through the L-V relationship.

Proton acceleration from picosecond-laser interaction with a hydrocarbon target

As an intense picosecond laser pulse irradiates a hydrocarbon target,the protons therein can be accelerated by the radiation pressure as well as the sheath field behind the target.We investigate the effect of the laser and hydrocarbon target parameters on proton acceleration with two/threedimensional particle-in-cell simulations.It is found that the resulting two-ion species plasma can generate a multiple peaked charge-separation field that accelerates the protons.In particular,a smaller carbon-to-hydrogen ratio,as well as the thinner and/or lower density of the target,leads to a larger sheath field and thus proton beams with a larger cutoff energy and smoother energy spectrum.These results may be useful in achieving high-flux quasi-monoenergetic proton beams by properly designing the hydrocarbon target.

Peak Particle Velocity Predicting Equation Associated with the Propagation of Vibrations Induced by Blasting in a Mine and Impacts on the Physical Degradation of Houses: The Case of the Yaramoko Mine, Bagassi, Burkina Faso

This study utilizes empirical equations to describe the propagation of vibrations induced by blasting, with the goal of predicting the attenuation of Peak Particle Velocity (PPV) at the Yaramoko mine in Bagassi, Burkina Faso, a site characterized by granitoid rock. Four empirical PPV prediction equations were employed, so-called Duvall & Fogelson (or the United States Bureau of Mines “USBM”), Langefors and Kihlstrom, Ambressys-Hendron, and the Bureau of Indian Standard. The constant parameters for each of these equations, referred to as site constants, were derived from linear regression curves. The results show that the site constants k, a, and b of 4762, 0.869, and 1.737, respectively, derived from the general prediction equation by Davies, PPV = kQaD−b, based on Duvall & Fogelson, are in good agreement with values of 4690, 0.9, and 1.69, respectively, for similar rock types in Spain. Regarding the impacts of blasting on houses, the findings indicate that houses built from laterite-block bricks in the village of Bagassi are the most vulnerable to vibration waves, followed by those constructed with cinder-block bricks. In contrast, houses made of banco bricks are the most resilient. Additionally, it was determined that during blasting operations, adjusting the blasting parameters to ensure the PPV does not exceed 2 mm/s at the level of nearby dwellings can minimize the appearance of cracks in houses.

Direct use of peak ground motion parameters for the estimation of inelastic displacement ratio of SDOF systems subjected to repeated far fault ground motions

This study is aimed at developing statistical equations to estimate the inelastic displacement ratio of singledegree-of-freedom systems subjected to far fault repeated earthquakes. In the study, peak ground motion parameters are used to define the scatter of the original data. The ratio of peak ground acceleration to peak ground velocity, and peak ground velocity of the ground motion records and structural parameters such as period of vibration and lateral strength ratio are used in the proposed equations. For the development of the equations, nonlinear time history analyses of single-degree-offreedom systems are conducted. Then, the results are used in a multivariate regression procedure. The equations are verified by comparing the estimated results with the calculated results. The average error and coefficient of variation of the proposed equations are presented. The analyses results revealed that the direct use of peak ground motion parameters for the estimation of inelastic displacement ratio significantly reduced the scatter in the original data and yielded accurate results. From the comparative results it is also observed that results obtained using equations specific to peak ground velocity or peak ground acceleration to peak ground velocity ratio are similar.

Influence of millisecond time,charge length and detonation velocity on blasting vibration

The law of blasting vibration caused by blasting in rock is very complex.Traditional numerical methods cannot well characterize all the influencing factors in the blasting process.The effects of millisecond time,charge length and detonation velocity on the blasting vibration are discussed by analyzing the characteristics of vibration wave generated by finite length cylindrical charge.It is found that in multi-hole millisecond blasting,blasting vibration superimpositions will occur several times within a certain distance from the explosion source due to the propagation velocity difference of P-wave and S-wave generated by a short column charge.These superimpositions will locally enlarge the peak velocity of blasting vibration particle.The magnitude and scope of the enlargement are closely related to the millisecond time.Meanwhile,the particle vibration displacement characteristics of rock under long cylindrical charge is analyzed.The results show that blasting vibration effect would no longer increase when the charge length increases to a certain extent.This indicates that the traditional simple calculation method using the maximum charge weight per delay interval to predict the effect of blasting vibration is unreasonable.Besides,the effect of detonation velocity on blasting vibration is only limited in a certain velocity range.When detonation velocity is greater than a certain value,the detonation velocity almost makes no impact on blasting vibration.

Artificial ground motion compatible with specified ground shaking peaks and target response spectrum

This article describes a hybrid simulation method to generate artificial ground motion time histories that are compatible with specified peak seismic acceleration, velocity and displacement as well as the target response spectrum of absolute acceleration. First, based on traditional methods that match the target spectrum in the frequency domain, an initial acceleration time history was synthesized to satisfy the specified peak acceleration, target spectral acceleration and intensity envelope. Second, by using the inversion formula of the seismic input to a linear single-degree-of-freedom system and by superimposing a series of narrow-band time histories in the time domain, the initial time history is further modified to allow its peak velocity and displacement to approach the targets and improve its matching precision with the target spectrum. Numerical examples are provided to demonstrate that the proposed method achieves good agreement with the target values.

Time derivative of earthquake acceleration

Unlike acceleration, velocity, and displacement, the time derivative ofacceleration (TDoA) of ground motion has not been extensively studied. In this paper, the basiccharacteristics of TDoA are evaluated based on records from the 1999 Chi-Chi, earthquake (Mw 7.6)and one of its aftershocks (Mw 6.2). It is found that the maximum TDoA at a free-field station wasover 31,200 cm/s3 (31.8 g/s); and the duration of 'strong' TDoA, between the first and the last timepoints exceeding 2,000 cm/s3 (2 g/s), was almost one minute near the epicenter area. Since groundTDoA sensors are not commonly available, the time series are calculated by direct numericaldifferentiation of acceleration time series. Relative error analysis shows that the error isnon-transitive and total error is within 4%. The density function of TDoA amplitude, frequencycontent and spatial distribution of peak ground jerk (PGJ) are evaluated. The study also includesexamination of some TDoA responses from a seven-story building and comparison of ground TDoA withthe limit TDoA used in the transportation industry for ride comfort. Some potential impacts of TDoAon humans have also been reviewed.