Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted t...Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted to develop conversion models between the acceleration response spectrum(SA)and the pseudo-acceleration response spectrum(PSA).Our previous studies found that the relationship between SA and PSA is affected by magnitude,distance,and site class.Subsequently,we developed an SA/PSA model incorporating these effects.However,this model is suitable for cases with small and moderate magnitudes and its accuracy is not good enough for cases with large magnitudes.This paper aims to develop an efficient SA/PSA model by considering influences of magnitude,distance,and site class,which can be applied to cases not only with small or moderate magnitudes but also with large ones.For this purpose,regression analyses were conducted using 16,660 horizontal seismic records with a wider range of magnitude.The magnitude of these seismic records varies from 4 to 9 and the distances vary from 10 to 200 km.These ground motions were recorded at 338 stations covering four site classes.By comparing them with existing models,it was found that the proposed model shows better accuracy for cases with any magnitudes,distances,and site classes considered in this study.展开更多
On November 26,2019 a strong earthquake of magnitude M6.4 occurred close to the City of Durrës,Albania(15.6 km WSW(west southwest)of Mamurras and 22 km SSW(south southwest)of Durrës),causing fatalities and c...On November 26,2019 a strong earthquake of magnitude M6.4 occurred close to the City of Durrës,Albania(15.6 km WSW(west southwest)of Mamurras and 22 km SSW(south southwest)of Durrës),causing fatalities and considerable damages in many buildings.In this article we present and analyze,by means of observational data and numerical simulation,the behavior under this earthquake of an 8-floor RC(reinforcement concrete)building,by using design spectra referring to KTP-N.2-89 and Eurocode 8.The main purpose of the authors is to better understand and evaluate the seismic performance of high-rise buildings under the design spectra with a period of soil oscillation close to the fundamental period of the structure.展开更多
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 lar...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.展开更多
The study of the relationship of local ground conditions with the parameters </span><span style="font-family:Verdana;">of seismic vibrations carried out by the section of engineering seismology&l...The study of the relationship of local ground conditions with the parameters </span><span style="font-family:Verdana;">of seismic vibrations carried out by the section of engineering seismology</span><span style="font-family:Verdana;"> called seismic microzonation. In</span><i> </i><span style="font-family:Verdana;">this branch of applied science radical changes have taken place at the end of the last century. The Commission on Seismic Safety of the National Institute of Building Sciences of the United States has developed new recommendations, which are significantly different from all that used in the world practice of anti-seismic construction. The main provisions of this NEHRP (National Earthquake Hazards Reduction Program) classifica</span><span style="font-family:Verdana;">tion adopted in many national building codes, including Eurocode 8. At the same time, a number of papers appeared in subsequent years criticizing the </span><span style="font-family:Verdana;">use of the NEHRP soil classification. This article examines in detail and, </span><span style="font-family:Verdana;">most</span><span style="font-family:Verdana;"> importantly, comprehensively the shortcomings of the NEHRP classification.展开更多
The site index table, site class table and quantizing model ofdahurian larch forests were formed based on 418 temporary plots and 179 dominant stem analysis trees. By testing raw data which were not used to form the s...The site index table, site class table and quantizing model ofdahurian larch forests were formed based on 418 temporary plots and 179 dominant stem analysis trees. By testing raw data which were not used to form the site index table, the site index table of plantations was validated. The site index table or site class table can be used in timber stands according to the intensive degrees of forest management. The quantizing model can be used in cutover, deforested and nonforested areas.展开更多
Site quality of larch(Larix gmelinii Rupr.)in Da Xingan Mountain in InnerMongolia was studied systematically with about 1000 temporary plots and computersoftware.The nature of site class and site index curve was discu...Site quality of larch(Larix gmelinii Rupr.)in Da Xingan Mountain in InnerMongolia was studied systematically with about 1000 temporary plots and computersoftware.The nature of site class and site index curve was discussed in view of generalmathematical model of height growth.The height growth of dominant tree of four divisionsof forest stands were studied and site index tables were constructed respectively.In orderto unify the comparing standard and convenience for management in this region,site indextable was constucted too.Based on discussing the action and accuracy of forest type,aseries of site quality evaluation(forest type-site index class-site index)was suggested.展开更多
Background: Surgical site infections (SSIs) are considered as result of the healthcare quality in hospitals. Objective: to study SSI at Saint Jean de Dieu Hospital Tanguieta (SJDHT), prior to the implementation of a p...Background: Surgical site infections (SSIs) are considered as result of the healthcare quality in hospitals. Objective: to study SSI at Saint Jean de Dieu Hospital Tanguieta (SJDHT), prior to the implementation of a permanent monitoring system. Method: transversal, and descriptive study with prospective data collection was performed from 1 July to 31 janvier 2017 in the department of general surgery of SJDHT. The hospital lacks in a microbiology unit. All patients who underwent surgery during this period were included and the monitoring lasted one month. SSIs diagnostic was carried out according to WHO criteria as described in the Practical Guide for the Prevention of Nosocomial Infections published in 2002. Statistical tests (χ-square and Student’s t-test) were applied and p 0.05 were statistically significant. Results: Of 343 patients recorded, 105 (30.6%) had SSI. Their age averaged 40.3 years and the sex-ratio (men/women) was 2.8. The emergency surgery resulted in a 50.0% rate of SSI (p = 0.00). The SSI rate for clean and clean-contaminated surgery was 6.3% against 94.6% for infected surgery (p = 0.00). The SSI rates were 100% and 66.7% for NNISS = 2 and NNISS = 1 (p = 0.00), respectively. Superficial SSI rate was 13.3%, while deep SSI and organ/space SSI were 46.7% and 40%, respectively. The hospital stay of patients with SSI was three times longer than the length of patients without SSI (p = 0.00). Conclusion: SSIs are real burden at SJDHT. Appropriate measures must be adopted to reduce its prevalence.展开更多
基金National Natural Science Foundation of China under Grant No.52278135。
文摘Both acceleration and pseudo-acceleration response spectra play important roles in structural seismic design.However,only one of them is generally provided in most seismic codes.Therefore,many studies have attempted to develop conversion models between the acceleration response spectrum(SA)and the pseudo-acceleration response spectrum(PSA).Our previous studies found that the relationship between SA and PSA is affected by magnitude,distance,and site class.Subsequently,we developed an SA/PSA model incorporating these effects.However,this model is suitable for cases with small and moderate magnitudes and its accuracy is not good enough for cases with large magnitudes.This paper aims to develop an efficient SA/PSA model by considering influences of magnitude,distance,and site class,which can be applied to cases not only with small or moderate magnitudes but also with large ones.For this purpose,regression analyses were conducted using 16,660 horizontal seismic records with a wider range of magnitude.The magnitude of these seismic records varies from 4 to 9 and the distances vary from 10 to 200 km.These ground motions were recorded at 338 stations covering four site classes.By comparing them with existing models,it was found that the proposed model shows better accuracy for cases with any magnitudes,distances,and site classes considered in this study.
文摘On November 26,2019 a strong earthquake of magnitude M6.4 occurred close to the City of Durrës,Albania(15.6 km WSW(west southwest)of Mamurras and 22 km SSW(south southwest)of Durrës),causing fatalities and considerable damages in many buildings.In this article we present and analyze,by means of observational data and numerical simulation,the behavior under this earthquake of an 8-floor RC(reinforcement concrete)building,by using design spectra referring to KTP-N.2-89 and Eurocode 8.The main purpose of the authors is to better understand and evaluate the seismic performance of high-rise buildings under the design spectra with a period of soil oscillation close to the fundamental period of the structure.
基金National Science Foundation of China under Grant No.51578470。
文摘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.
文摘The study of the relationship of local ground conditions with the parameters </span><span style="font-family:Verdana;">of seismic vibrations carried out by the section of engineering seismology</span><span style="font-family:Verdana;"> called seismic microzonation. In</span><i> </i><span style="font-family:Verdana;">this branch of applied science radical changes have taken place at the end of the last century. The Commission on Seismic Safety of the National Institute of Building Sciences of the United States has developed new recommendations, which are significantly different from all that used in the world practice of anti-seismic construction. The main provisions of this NEHRP (National Earthquake Hazards Reduction Program) classifica</span><span style="font-family:Verdana;">tion adopted in many national building codes, including Eurocode 8. At the same time, a number of papers appeared in subsequent years criticizing the </span><span style="font-family:Verdana;">use of the NEHRP soil classification. This article examines in detail and, </span><span style="font-family:Verdana;">most</span><span style="font-family:Verdana;"> importantly, comprehensively the shortcomings of the NEHRP classification.
文摘The site index table, site class table and quantizing model ofdahurian larch forests were formed based on 418 temporary plots and 179 dominant stem analysis trees. By testing raw data which were not used to form the site index table, the site index table of plantations was validated. The site index table or site class table can be used in timber stands according to the intensive degrees of forest management. The quantizing model can be used in cutover, deforested and nonforested areas.
基金This subject of study is supported by the National Natural Scientific Fund(No.39270549)
文摘Site quality of larch(Larix gmelinii Rupr.)in Da Xingan Mountain in InnerMongolia was studied systematically with about 1000 temporary plots and computersoftware.The nature of site class and site index curve was discussed in view of generalmathematical model of height growth.The height growth of dominant tree of four divisionsof forest stands were studied and site index tables were constructed respectively.In orderto unify the comparing standard and convenience for management in this region,site indextable was constucted too.Based on discussing the action and accuracy of forest type,aseries of site quality evaluation(forest type-site index class-site index)was suggested.
文摘Background: Surgical site infections (SSIs) are considered as result of the healthcare quality in hospitals. Objective: to study SSI at Saint Jean de Dieu Hospital Tanguieta (SJDHT), prior to the implementation of a permanent monitoring system. Method: transversal, and descriptive study with prospective data collection was performed from 1 July to 31 janvier 2017 in the department of general surgery of SJDHT. The hospital lacks in a microbiology unit. All patients who underwent surgery during this period were included and the monitoring lasted one month. SSIs diagnostic was carried out according to WHO criteria as described in the Practical Guide for the Prevention of Nosocomial Infections published in 2002. Statistical tests (χ-square and Student’s t-test) were applied and p 0.05 were statistically significant. Results: Of 343 patients recorded, 105 (30.6%) had SSI. Their age averaged 40.3 years and the sex-ratio (men/women) was 2.8. The emergency surgery resulted in a 50.0% rate of SSI (p = 0.00). The SSI rate for clean and clean-contaminated surgery was 6.3% against 94.6% for infected surgery (p = 0.00). The SSI rates were 100% and 66.7% for NNISS = 2 and NNISS = 1 (p = 0.00), respectively. Superficial SSI rate was 13.3%, while deep SSI and organ/space SSI were 46.7% and 40%, respectively. The hospital stay of patients with SSI was three times longer than the length of patients without SSI (p = 0.00). Conclusion: SSIs are real burden at SJDHT. Appropriate measures must be adopted to reduce its prevalence.
