A simulation-based nonlinear site amplification model for ground-motion prediction equations in Japan

In this manuscript we present a nonlinear site amplification model for ground-motion prediction equations(GMPEs)in Japan,using a site period-based site class and a site impedance ratio as site parameters.We used a large number of shear-wave velocity profiles from the Kiban-Kyoshin network(KiK-net)and the Kyoshin network(K-NET)to construct the one-dimensional(1D)numerical models.The strong-motion records from rock-sites in Japan with different earthquake categories and taken from the Pacific Earthquake Engineering Research Center dataset were used in this study.We fit a set of 1D site amplification models using the spectral amplification ratios derived from 1D equivalent linear analyses.Parameters of site impedance ratios for both linear and nonlinear site response were included in the 1D model.The 1D model could be implemented into GMPEs using a new proposed adjustment method.The adjusted site amplification ratios retain the nonlinear characteristics of the 1D model for strong motions and match the linear amplification ratio in GMPE for weak motions.The nonlinearity of the present site model is reasonably similar to that of the historical models,and the present site model could satisfactorily capture the nonlinear site response in empirical data.

Effect of Recycled Aggregate and Slag as Substitutes for Natural Aggregate and Cement on the Properties of Concrete:A Review

Using recycled aggregate(RA)and slag instead of natural aggregate(NA)and cement can reduce greenhouse gas emissions(GHGE)and achieve effective waste recovery.In recent years,RA has been widely used to replace NA in concrete.Every year,several researchers conduct investigations on the mechanical performance and durability of recycled aggregate concrete(RAC).Due to the loose and porous material properties of RA,the mechanical properties and durability of RAC,such as strength,carbonation resistance,permeability resistance and chloride ion penetration resistance,are greatly reduced compared with natural aggregate concrete.In contrast,concrete containing slag instead of NA and cement generally improved the strength of concrete and reduced the internal porosity of materials.Herein,we discuss the effects of RA and slag on the workability,compressive strength,splitting tensile strength,ultrasonic pulse velocity(UPV)value,and elastic modulus of concrete.The relationships between the compressive strength and the splitting tensile strength,UPV value,and elastic modulus are discussed,and the optimal substitution method is proposed.In addition,various equations for calculating the compressive strength of concrete based on performance factors related to the compressive strength are summarized.

Rapid assessment of the September 5,2022 M_(S)6.8 Luding earthquake in Sichuan,China

At 12:52,September 5,2022,an M_(S)6.8 earthquake occurred in Luding,Sichuan.The earthquake caused serious casualties and property loss,and was determined to have an epicenter intensity of Ⅸ degree.In this study,we used three earthquake intensity rapid assessment methods(i.e.WFM,BPM and ASM) to evaluate the intensity of this earthquake.Then,we comparatively analyzed the three methods based on strong ground motion observation data and actual intensity maps.The results show that:(1) The earthquake is associated with a southeast-oriented single-sided rupture.The WFM method can only evaluate earthquakes with two-sided ruptures,which has some limitations;(2) The intensity of BPM and ASM was overestimated on the southwest and north sides of the epicenter,but other high-intensity zones were similar to the intensities measured by actual surveys;(3) The residuals of the three intensity assessment methods were all between-0.5 and 1.Although a small number of stations were underestimated,the overall residuals were good,and the residuals gradually approached 0 with the increase of distance;(4) The number of towns and villages evaluated by the three methods in the earthquake area was almost all lower than the field survey results.One exception is the area of Ⅷ degree,where the BPM and ASM were higher than the survey results;(5) The area of the earthquake area evaluated by the three methods was low in Ⅵ and Ⅶ degree,moderate in Ⅷ degree,and low in Ⅸ degree(the area from ASM is similar to the area measured by actual survey).Overall,ASM is applicable to this earthquake intensity assessment.

An investigation of the influence of near-fault ground motion parameters on the pile's response in liquefiable soil

The performance of a soil-pile system can be significantly influenced by ground motion parameters. However, few research efforts have been performed to provide a complete description of the influence of key ground motion parameters on the pile’s behavior in liquefiable soil. In this study, a three-dimensional finite element（FE） model, incorporating a multisurface plasticity solid-fluid fully coupled formulation soil constitutive model, is developed and calibrated based on centrifuge test data. Seventy-two near-fault non-pulse-like（NF-NP） and seventy-two near-fault pulse-like（NF-P） ground motion records are studied with the calibrated FE model to distinguish the effects of several common ground motion parameters soon afterwards. Base on the parametric study results, a simple index, RPGV/PGA（i.e., the ratio of peak ground velocity（PGV） to peak ground acceleration（PGA））, shows its capability on characterizing the pile behavior under both NF-NP and NF-P ground motions. Furthermore, two equations are developed to characterize the relationships between the RPGV/PGA as well as the maximum pile’s moments and displacements. In general, this study can be helpful to gain new insights on the influence of typical index parameters for near-field ground motions on the response of the pile foundation in liquefiable soil.

Basal Energy Expenditure of Chinese Healthy Adults:Comparison of Measured and Predicted Values

Objective This study aimed to measure the basal energy expenditure(BEE)of Chinese healthy adults and establish an accurate predictive equation for this population.Methods In total,470 Chinese healthy adults had their BEE measured using the Cosmed K4b2 portable metabolic system.Multiple linear regression analysis was applied to develop new optimal equations for predicting BEE.The bias,accuracy rate,concordance correlation coefficient(CCC),and root mean square error(RMSE)were used to evaluate the accuracy of the predictive equations.Results There was a significant difference in BEE between males and females,with 5,954 kJ/d and 5,089 kJ/d,respectively.People living in rural areas expended significantly higher BEE(5,885 kJ/d)than those in urban areas(5,279 kJ/d).Previous equations developed by Henry,Schofield,Harris-Benedict(HB),and Liu overestimated the BEE of Chinese healthy adults.The new equations derived from the present study displayed the smallest average bias and RMSE from the measured basal energy expenditure(mBEE).The CCC of the new equations was higher than other predictive equations,but it was lower than 0.8.There was no significant difference in the accuracy rate among all predictive equations.Conclusions Sex and regional differences in BEE were observed in Chinese healthy adults.Neither the widely used previous predictive equations nor the one derived in the present study were accurate enough for estimating the BEE of Chinese healthy adults.Further study is required to develop more accurate equations for predicting the BEE of Chinese healthy adults aged between 20–45 years.

Comparison of dominant frequency attenuation of blasting vibration for different charge structures

Dominant frequency attenuation is a significant concern for frequency-based criteria of blasting vibration control.It is necessary to develop a concise and practical prediction equation describing dominant frequency attenuation.In this paper,a prediction equation of dominant frequency that accounts for primary parameters influencing the dominant frequency was proposed based on theoretical and dimensional analyses.Three blasting experiments were carried out in the Chiwan parking lot for collecting blasting vibration data used to conduct regression analysis of the proposed prediction equation.The fitting equations were further adopted to compare the reliability of three different types of dominant frequencies in the proposed equation and to explore the effects of different charge structures on the dominant frequency attenuation.The apparent frequency proved to be more reliable to express the attenuation law of the dominant frequency.The reliability and superiority of the proposed equation employing the apparent frequency were verified by comparison with the other five prediction equations.The smaller blasthole diameter or decoupling ratio leads to the higher initial value and corresponding faster attenuation of the dominant frequency.The blasthole diameter has a greater influence on the dominant frequency attenuation than the decoupling ratio does.Among the charge structures applied in the experiments,the charge structure with decoupling ratio of 1.5 and blasthole diameter of 48 mm results in the greatest initial value and corresponding fastest attenuation of the dominant frequency.

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.

Predicting corn digestible and metabolizable energy content from its chemical composition in growing pigs

Background： The nutrient composition of corn is variable. To prevent unforeseen reductions in growth performance, grading and analytical methods are used to minimize nutrient variability between calculated and analyzed values. This experiment was carried out to define the sources of variation in the energy content of corn and to develop a practical method to accurately estimate the digestible energy （DE） and metabolisable energy （ME） content of individual corn samples for growing pigs. Twenty samples were taken from each of five provinces in China （Jilin, Hebei, Shandong, Liaoning, and Henan） to obtain a range of quality. Results： The DE and ME contents of the 100 corn samples were measured in 3.5.3 ±1.92 kg growing pigs （six pigs per corn sample）. Sixty corn samples were used to build the prediction model; the remaining forty samples were used to test the suitability of these models. The chemical composition of each corn sample was determined, and the results were used to establish prediction equations for DE or ME content from chemical characteristics. The mean DE and ME content of the 100 samples were 4,053 and 3,923 kcal/kg （dry matter basis）, respectively. The physical characteristics were determined, as well, and the results indicated that the bulk weight and 1,000-kernel weight were not associated with energy content. The DE and ME values could be accurately predicted from chemical characteristics. The best fit equations were as follows： DE, kcal/kg of DM = 1062.68 ＋ （49.72 ×EE） ＋ （0.54 × GE） ＋ （9.1 ] x starch）, with R^2 = 0.62, residual standard deviation （RSD） = 48 kcal/kg, and P 〈 0.01; ME, kcal/kg of dry matter basis （DM） = 671.54 ＋ （0.89 ×DE） - （5.57 × NDF） - （191.39 ×ash）, with R^2 = 0.87, RSD = 18 kcal/kg, and P〈 0.01. Conclusion： This experiment confirms the large variation in the energy content of corn, describes the factors that influence this variation, and presents equations based on chemical measurements that may be used to predict the DE and ME content of individual corn samples.

Quantification and prediction of enteric methane emissions from Chinese lactating Holstein dairy cows fed diets with different dietary neutral detergent fiber/non-fibrous carbohydrate(NDF/NFC)ratios

Methane(CH_(4))emissions from ruminant production are a significant source of anthropogenic greenhouse gas production,but few studies have examined the enteric CH_(4)emissions of lactating dairy cows under different feeding regimes in China.This study aimed to investigate the influence of different dietary neutral detergent fiber/non-fibrous carbohydrate(NDF/NFC)ratios on production performance,nutrient digestibility,and CH_(4)emissions for Holstein dairy cows at various stages of lactation.It evaluated the performance of CH_(4)prediction equations developed using local dietary and milk production variables compared to previously published prediction equations developed in other production regimes.For this purpose,36 lactating cows were assigned to one of three treatments with differing dietary NDF/NFC ratios:low(NDF/NFC=1.19),medium(NDF/NFC=1.54),and high(NDF/NFC=1.68).A modified acid-insoluble ash method was used to determine nutrient digestibility,while the sulfur hexafluoride technique was used to measure enteric CH4 emissions.The results showed that the dry matter(DM)intake of cows at the early,middle,and late stages of lactation decreased significantly(P<0.01)from 20.9 to 15.4 kg d^(–1),15.3 to 11.6 kg d^(–1),and 16.4 to 15.0 kg d^(–1),respectively,as dietary NDF/NFC ratios increased.Across all three treatments,DM and gross energy(GE)digestibility values were the highest(P<0.05)for cows at the middle and late lactation stages.Daily CH_(4)emissions increased linearly(P<0.05),from 325.2 to 391.9 kg d^(–1),261.0 to 399.8 kg d^(–1),and 241.8 to 390.6 kg d^(–1),respectively,as dietary NDF/NFC ratios increased during the early,middle,and late stages of lactation.CH_(4)emissions expressed per unit of metabolic body weight,DM intake,NDF intake,or fat-corrected milk yield increased with increasing dietary NDF/NFC ratios.In addition,CH_(4)emissions expressed per unit of GE intake increased significantly(P<0.05),from 4.87 to 8.12%,5.16 to 9.25%,and 5.06 to 8.17%respectively,as dietary NDF/NFC ratios increased during the early,middle,and late lactation stages.The modelling results showed that the equation using DM intake as the single variable yielded a greater R^(2)than equations using other dietary or milk production variables.When data obtained from each lactation stage were combined,DM intake remained a better predictor of CH_(4)emissions(R^(2)=0.786,P=0.026)than any other variables tested.Compared to the prediction equations developed herein,previously published equations had a greater root mean square prediction error,reflecting their inability to predict CH_(4)emissions for Chinese Holstein dairy cows accurately.The quantification of CH_(4)production by lactating dairy cows under Chinese production systems and the development of associated prediction equations will help establish regional or national CH_(4)inventories and improve mitigation approaches to dairy production.

The correlationship between the metabolizable energy content,chemical composition and color score in different sources of corn DDGS

Background： This study was conducted to evaluate the apparent metabolizable energy （AME） and true metabolizable energy （TME） contents in 30 sources of corn distillers dried grains with solubles （DDGS） in adult roosters, and establish the prediction equations to estimate the AME and TME value based on its chemical composition and color score. Methods： Twenty-eight sources of corn DDGS made from several processing plants in 11 provinces of China and others imported from the United States. DDGS were analyzed for their metabolizable energy （ME） contents, measured for color score and chemical composition （crude protein, crude fat, ash, neutral detergent fiber, acid detergent fiber）, to predict the equation of ME in DDGS. A precision-fed rooster assay was used, each DDGS sample was tube fed （50 g） to adult roosters. The experiment was conducted as a randomized incomplete block design with 3 periods. Ninety-five adult roosters were used in each period, with 90 being fed the DDGS samples and 5 being fasted to estimate basal endogenous energy losses. Results： Results showed that the AME ranged from 5.93 to 12.19 MJ/kg, TME ranged from 7.28 to 13.54 MJ/kg. Correlations were found between ME and ash content （-0.64, P 〈 0.0]） and between ME and yellowness score （0.39, P 〈 0.05） of the DDGS samples. Furthermore, the best-fit regression equation for AME content of DDGS based on chemical composition and color score was AME = 6.57111 ＋ 0.5]475 GE - 0.10003 NDF ＋ 0.1 3380 ADF ＋ 0.07057 fat - 0.57029 ash - 0.02437 L （R^2 = 0.70）. The best-fit regression equation for TME content of DDGS was TME = 7.92283 ＋ 0.51475 GE - 0.10003 NDF ＋ 0.13380 ADF ＋ 0.07057 fat - 0.57029 ash - 0.02437 L （R2 = 0.70）. Conclusions： This experiment suggested that measuring the chemical composition and color score of a corn DDGS sample may provide a quality parameter for identifying corn DDGS sources energy digestibility and metabolizable energy content.

Characteristics of horizontal ground motion measures along principal directions

Ground motion records are often used to develop ground motion prediction equations （GMPEs） for a randomly oriented horizontal component, and to assess the principal directions of ground motions based on the Arias intensity tensor or the orientation of the major response axis. The former is needed for seismic hazard assessment, whereas the latter can be important for assessing structural responses under multi-directional excitations. However, a comprehensive investigation of the pseudo-spectral acceleration （PSA） and of GMPEs conditioned on different axes is currently lacking. This study investigates the principal directions of strong ground motions and their relation to the orientation of the major response axis, statistics of the PSA along the principal directions on the horizontal plane, and correlation of the PSA along the principal directions on the horizontal plane. For these, three sets of strong ground motion records, including intraplate California earthquakes, inslab Mexican earthquakes, and interface Mexican earthquakes, are used. The results indicate that one of the principal directions could be considered as quasi-vertical. By focusing on seismic excitations on the horizontal plane, the statistics of the angles between the major response axis and the major principal axis are obtained; GMPEs along the principal axes are provided and compared with those obtained for a randomly oriented horizontal component; and statistical analysis of residuals associated with GMPEs along the principal directions is carried out.

Hysteretic energy prediction method for mainshock-aftershock sequences

Structures located in seismically active regions may be subjected to mainshock-aftershock（MSAS）sequences.present study selected two kinds of MSAS sequences,with one aftershock and two aftershocks,respectively.The aftershocksThe MSAS sequence with one aftershock exhibited a 10%to 30%hysteretic energy increase,whereas the MSAS sequence with two aftershocks presented a 20%to 40%hysteretic energy increase.Finally,a hysteretic energy prediction equation is proposed as a function of the vibration period,ductility value,and damping ratio to estimate hysteretic energy for mainshockaftershock sequences.

Comparison of strong-motion records and damage implications between the 2014 Yunnan M_S6.5 Ludian earthquake and M_S6.6 Jinggu earthquake

Serial destructive earthquakes have caused heavy casualties and economic losses to the city in southwestern of China. The Ludian Ms 6.5 earthquake and the Jinggu Ms 6.6 earthquake occurred in Yunnan province in 2014. There is a question of why the two events with almost the same level of magnitude caused differences in earthquake damage. To understand the uniqueness of the phenomenon, this paper focuses on the characteristics of the ground motions and post-earthquake field investigation for the two events. Firstly, we present an overview of the residuals between the Ludian earthquake and the Jinggu earthquake based on the YW06 Ground Motion Prediction Equation （GMPE）, and explain the unusual destructiveness of the strong ground motion. Then we analyze the ground motion recordings at selected typical station, based on the strong motion parameters： equivalent predominant frequency and Arias intensity. The result exhibits a good agreement with the Chinese seismic intensity scale. This study would be helpful to gain a better knowledge of the characteristics and variability of ground motions for Ms6 class earthquakes in China and to understand the implications to future earthquakes with similar focal mechanism and local condition.

Improved Quality Prediction Model for Multistage Machining Process Based on Geometric Constraint Equation

Product variation reduction is critical to improve process efficiency and product quality, especially for multistage machining process（MMP）. However, due to the variation accumulation and propagation, it becomes quite difficult to predict and reduce product variation for MMP. While the method of statistical process control can be used to control product quality, it is used mainly to monitor the process change rather than to analyze the cause of product variation. In this paper, based on a differential description of the contact kinematics of locators and part surfaces, and the geometric constraints equation defined by the locating scheme, an improved analytical variation propagation model for MMP is presented. In which the influence of both locator position and machining error on part quality is considered while, in traditional model, it usually focuses on datum error and fixture error. Coordinate transformation theory is used to reflect the generation and transmission laws of error in the establishment of the model. The concept of deviation matrix is heavily applied to establish an explicit mapping between the geometric deviation of part and the process error sources. In each machining stage, the part deviation is formulized as three separated components corresponding to three different kinds of error sources, which can be further applied to fault identification and design optimization for complicated machining process. An example part for MMP is given out to validate the effectiveness of the methodology. The experiment results show that the model prediction and the actual measurement match well. This paper provides a method to predict part deviation under the influence of fixture error, datum error and machining error, and it enriches the way of quality prediction for MMP.

Bi-variable damage model for fatigue life prediction of metal components

Based on the theory of continuum damage mechanics,a bi-variable damage mechanics model is developed,which,according to thermodynamics,is accessible to derivation of damage driving force,damage evolution equation and damage evolution criteria. Furthermore,damage evolution equations of time rate are established by the generalized Drucker＇s postulate. The damage evolution equation of cycle rate is obtained by integrating the time damage evolution equations,and the fatigue life prediction method for smooth specimens under repeated loading with constant strain amplitude is constructed. Likewise,for notched specimens under the repeated loading with constant strain amplitude,the fatigue life prediction method is obtained on the ground of the theory of conservative integral in damage mechanics. Thus,the material parameters in the damage evolution equation can be obtained by reference to the fatigue test results of standard specimens with stress concentration factor equal to 1,2 and 3.

Engineering Analysis of Strong Motion Data from Recent Earthquakes in Sichuan, China

Recent earthquakes in the Sichuan Province have contributed to significantly expand the existing ground-motion database for China with new,high-quality ground-motion records.This study investigated the compatibility of ground-motion prediction equations(GMPEs)established by the NGA-West2 project in the US and local GMPEs for China,with respect to magnitude scaling,distance scaling,and site scaling implied by recent Chinese strong-motion data.The NGA-West2 GMPEs for shallow crustal earthquakes in tectonically active regions are considerably more sophisticated than widely used previous models,particularly in China.Using a mixed-effects procedure,the study evaluated event terms(inter-event residuals)and intra-event residuals of Chinese data relative to the NGA-West2 GMPEs.Distance scaling was investigated by examining trends of intra-event residuals with source-to-site distance.Scaling with respect to site conditions was investigated by examining trends of intra-event residuals with soil type.The study also investigated other engineering characteristics of Chinese strong ground motions.In particular,the records were analyzed for evidence of pulse-like forward-directivity effects.The elastic median response spectra of the selected stations were compared to code-mandated design spectra for various mean return periods.Results showed that international and local GMPEs can be applied for seismic hazard analysis in Sichuan with minor modification of the regression coefficients related to the source-to-site distance and soil scaling.Specifically,the Chinese data attenuated faster than implied by the considered GMPEs and the differences were statistically significant in some cases.Near-source,pulse-like ground motions were identified at two recording stations for the 2008 Wenchuan earthquake,possibly implying rupture directivity.The median recorded spectra were consistent with the code-based spectra in terms of amplitude and shape.The new ground-motion data can be used to develop advanced ground-motion models for China and worldwide and,ultimately,for advancing probabilistic seismic hazard assessment(PSHA).

The dependence of response spectrum on the tectonic ambient shear stress field

It has been analyzed the influence of the tectonic ambient shear stress value on response spectrum based on the previous theory. Based on the prediction equation BJF94 presented by the famous American researchers, CLB20, a new prediction formula is proposed by us, where it is introduced the influence of tectonic ambient shear stress value on response spectrum. BJF94 is the prediction equation, which mainly depends on strong ground motion data from western USA, while the prediction equation SEA99 is based on the strong ground motion data from exten-sional region all over the world. Comparing these two prediction equations in detail, it is found that after BJF94′s prediction value lg(Y) minus 0.16 logarithmic units, the value is very close to SEA99′s one. This case demonstrates that lg(Y) in extensional region is smaller; the differences of prediction equation are mainly owe to the differences of tectonic ambient shear stress value. If the factor of tectonic ambient shear stress value is included into the pre-diction equation, and the magnitude is used seismic moment magnitude to express, which is universal used around the world, and the distance is used the distance of fault project, which commonly used by many people, then re-gional differences of prediction equation will become much less, even vanish, and it can be constructed the uni-versal prediction equation proper to all over the world. The error in the earthquake-resistant design in China will be small if we directly use the results of response spectrum of USA (e.g. BJF94 or SEA99).

Macroseismic intensity attenuation in Iran

Macroseismic intensity data plays an important role in the process of seismic hazard analysis as well in developing of reliable earthquake loss models. This paper presents a physical-based model to predict macroseismic intensity attenuation based on 560 intensity data obtained in Iran in the time period 1975-2013. The geometric spreading and energy absorption of seismic waves have been considered in the proposed model. The proposed easy to implement relation describes the intensity simply as a function of moment magnitude, source to site distance and focal depth. The prediction capability of the proposed model is assessed by means of residuals analysis. Prediction results have been compared with those of other intensity prediction models for Italy, Turkey, Iran and central Asia. The results indicate the higher attenuation rate for the study area in distances less than 70 km.

Estimating Seismic Intensity Maps of the 2021 Mw 7.3 Madoi,Qinghai and Mw 6.1 Yangbi,Yunnan,China Earthquakes

This study focuses on rapidly determining seismic intensity maps of earthquakes because it offers fundamental information for effective emergency rescue and subsequent scientific research,and remains challenging to accurately determine seismic intensity map in regions with sparse instrumental observations.Here we applied a novel method that consisted of array technology(backprojection),ground-motion prediction equations,and site corrections,to estimate the seismic intensity maps of the 2021 Mw 7.3 Madoi,Qinghai and the Mw 6.1 Yangbi,Yunnan,China earthquakes.We used seismic data recorded at European stations to back-project the source processes of the 2021 Mw7.3 Madoi,Qinghai and the Mw 6.1 Yangbi,Yunnan,China earthquakes.The back-projected energy radiations were then used as subevents or used to define the fault geometry.Summing the contributions of each subevent or estimating the shortest distances from each site to the rupture fault,we obtained the ground motion(PGA and PGV)for each site under rock site conditions.The estimated ground motions were corrected at each site for local site amplification according to the Vs30 database.Our estimated seismic intensity maps and field reports showed high similarity,which further validated the effectiveness of the novel approach,and pushed the limit of earthquake size down to~M 6.Such efforts would substantially help in the fast and accurate evaluation of earthquake damage,and precise rescue efforts.

A prediction of the acoustic field of a vibrating box by FEM-BEM

A method based on Holmholtz equation is presented to predict thc acoustic radiation of a vibrating box by combining the finite clement method (FEM) with boundary element method (BEM). The prediction formulation is valid for all frequencies if an extra equation is added. The acoustic field of a vibrating box has been calculated and measured. The effectiveness of the method has been proved by test results.