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Key technologies of earthquake early warning system for China’s high-speed railway
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作者 Geming Zhang Lin Yang Wenxiang Jiang 《Railway Sciences》 2024年第2期239-262,共24页
Purpose–The purpose of this study is to introduce the top-level design ideas and the overall architecture of earthquake early-warning system for high speed railways in China,which is based on P-wave earthquake early-... Purpose–The purpose of this study is to introduce the top-level design ideas and the overall architecture of earthquake early-warning system for high speed railways in China,which is based on P-wave earthquake early-warning and multiple ways of rapid treatment.Design/methodology/approach–The paper describes the key technologies that are involved in the development of the system,such as P-wave identification and earthquake early-warning,multi-source seismic information fusion and earthquake emergency treatment technologies.The paper also presents the test results of the system,which show that it has complete functions and its major performance indicators meet the design requirements.Findings–The study demonstrates that the high speed railways earthquake early-warning system serves as an important technical tool for high speed railways to cope with the threat of earthquake to the operation safety.The key technical indicators of the system have excellent performance:The first report time of the P-wave is less than three seconds.From the first arrival of P-wave to the beginning of train braking,the total delay of onboard emergency treatment is 3.63 seconds under 95%probability.The average total delay for power failures triggered by substations is 3.3 seconds.Originality/value–The paper provides a valuable reference for the research and development of earthquake early-warning system for high speed railways in other countries and regions.It also contributes to the earthquake prevention and disaster reduction efforts. 展开更多
关键词 earthquake early-warning high speed railway China earthquake networks center(CENC) earthquake emergency treatment
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The Application of China's High Speed Railway Earthquake Early Warning System in Jakarta-Bandung HSR
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作者 YANG Lin ZHU Jinjing +1 位作者 ZHANG Xiuguang ZHANG Yiran(Translated) 《Chinese Railways》 2024年第1期62-70,共9页
Earthquake has a significant impact on operation safety of the high speed railway,and for Jakarta-Bandung High Speed Railway(HSR)in Indonesia where it is earthquake-prone,it is necessary to establish an earthquake ear... Earthquake has a significant impact on operation safety of the high speed railway,and for Jakarta-Bandung High Speed Railway(HSR)in Indonesia where it is earthquake-prone,it is necessary to establish an earthquake early warning system to strengthen its earthquake resistance.Based on the principle and technical characteristics of China's high speed railway earthquake early warning system and combining the actual situations of Jakarta-Bandung HSR in Indonesia,this paper describes how to implement China's high speed railway earthquake early warning system in Jakarta-Bandung HSR.It focuses on optimizations in environmental adaptation design and seismic network interface design,earthquake attenuation model parameter adjustment and terminal software interface adjustment,so as to make the system better suit the local situations,and meet operation requirements and guarantee safe operation of Jakarta-Bandung HSR. 展开更多
关键词 Jakarta-Bandung HSR China's high speed railway earthquake early warning system attenuation model Indonesia localized application
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Internal structures and high-velocity frictional properties of a bedding-parallel carbonate fault at Xiaojiaqiao outcrop activated by the 2008 Wenchuan earthquake 被引量:6
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作者 Toshihiko Shimamoto 《Earthquake Science》 CSCD 2012年第3期197-217,共21页
This paper reports internal structures of a bedding-parallel fault in Permian limestone at Xiaoji-aqiao outcrop that was moved by about 0.5 m during the 2008 MW7.9 Wenchuan earthquake. The fault is located about 3 km ... This paper reports internal structures of a bedding-parallel fault in Permian limestone at Xiaoji-aqiao outcrop that was moved by about 0.5 m during the 2008 MW7.9 Wenchuan earthquake. The fault is located about 3 km to the south from the middle part of Yingxiu-Beichuan fault, a major fault in the Longmenshan fault system that was moved during the earthquake. The outcrop is also located at Anxian transfer zone between the northern and central segments of Yingxiu-Beichuan fault where fault system is complex. Thus the fault is an example of subsidiary faults activated by Wenchuan earthquake. The fault has a strike of 243°or N63°E and a dip of 38°NW and is nearly optimally oriented for thrust motion, in contrast to high-angle coseismic faults at most places. Surface outcrop and two shallow drilling studies reveal that the fault zone is several centimeters wide at most and that the coseismic slip zone during Wenchuan earthquake is about 1 mm thick. Fault zone contains foliated cataclasite, fault breccia, black gouge and yellowish gouge. Many clasts of foliated cataclasite and black gouge contained in fault breccia indicate multiple slip events along this fault. But fossils on both sides of fault do not indicate clear age difference and overall displacement along this fault should not be large. We also report results from high-velocity friction experiments conducted on yellowish gouge from the fault zone using a rotary shear low to high-velocity frictional testing apparatus. Dry experiments at normal stresses of 0.4 to 1.8 MPa and at slip rates of 0.08 to 1.35 m/s reveal dramatic slip weakening from the peak friction coeffcient of around 0.6 to very low steady-state friction coeffcient of 0.1–0.2. Slip weakening parameters of this carbonate fault zone are similar to those of clayey fault gouge from Yingxiu-Beichuan fault at Hongkou outcrop and from Pingxi fault zone. Our experimental result will provide a condition for triggering movement of subsidiary faults or off-fault damage during a large earthquake. 展开更多
关键词 Wenchuan earthquake Longmenshan fault system carbonate fault rock high velocity friction dynamic weakening of fault
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High-velocity frictional behavior of Longmenshan fault gouge from Hongkou outcrop and its implications for dynamic weakening of fault during the 2008 Wenchuan earthquake 被引量:14
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作者 Tetsuhiro Togo Toshihiko Shimamoto +1 位作者 Shengli Ma Takehiro Hirose 《Earthquake Science》 CSCD 2011年第3期267-281,共15页
High-velocity friction experiments were conducted on clayey fault gouge collected from Hongkou outcrop of Beichuan fault, located at the southwestern part of Longmenshan fault system that caused the disastrous 2008 We... High-velocity friction experiments were conducted on clayey fault gouge collected from Hongkou outcrop of Beichuan fault, located at the southwestern part of Longmenshan fault system that caused the disastrous 2008 Wenchuan earthquake. The ultimate purpose of this study is to reproduce this earthquake by modeling based on measured frictional properties. Dry gouge of about 1 mm in thickness was deformed dry at slip rates of 0.01 to 1.3 m/s and at normal stresses of 0.61 to 3.04 MPa, using a rotary-shear high-velocity frictional testing machine. The gouge displays slip weakening behavior as initial peak friction decays towards steady-state values after a given displacement. Both peak friction and steady-state friction remain high at slow slip rates are exam- ined and gouge only exhibits dramatic weakening at high slip rates, with steady-state friction coefficient values of about 0.1 to 0.2. Specific fracture energy ranges from 1 to 4 MN/m in our results and this is of the same order as seismically determined values. Low friction coefficients measured on experimental faults are in broad agree- ment with lack of thermal anomaly observed from temperature measurements in WFSD-1 drill hole (Wenchuan Earthquake Fault Scientific Drilling Project), which can be explained by even smaller friction coefficient for the Wenchuan earthquake fault. High-velocity friction experiments with pore water needs to be done to see if even smaller friction is attained or not. Shiny slickenside surfaces form at high slip rates, but not at slow slip rates. Slip zone with slickenside surface changes its color to dark brown and forms duplex-like microstructures, which are similar to those microstructures found in the fault gouges from the Hongkou outcrop. Detailed comparisons between experimentally deformed gouge samples and WFSD drill cores in the future will reveal how much we could reproduce the dynamic weakening processes in operation in fault zones during Wenchuan earthquake at present. 展开更多
关键词 Wenchuan earthquake high-velocity friction fault mechanics Longmenshan fault system Beichuan fault
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Several Typical Geomechanical Models of Deformation Fracture of Mountain in High Earthquake Intensity Area
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作者 Xiangning Xu,Lansheng Wang 1.Chengdu University of Technology,Chengdu,610059,China. 2.Chengdu Center of Hydrogeology and Engineering Geology of Sichuan Provincial GMR Bureau,Chengdu,610081,China 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期72-72,共1页
The deformation fracture and stability of mountain under the earthquake action is an important issue that arouses concern of researchers in the field of engineering geology.The authors,from 2000 to 2006, selected the ... The deformation fracture and stability of mountain under the earthquake action is an important issue that arouses concern of researchers in the field of engineering geology.The authors,from 2000 to 2006, selected the 1933 earthquake in Diexi zone as a typical study site to carry out the genetic mechanism research of mountain deformation-fracture caused by earthquake; in order to have comparability,the breadth 展开更多
关键词 high earthquake intensity area DEFORMATION FRACTURE mechanism Geo-mechanical MODEL bedded LANDSLIDE MODEL COLLAPSING MODEL LANDSLIDE MODEL
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Internal structures and high-velocity frictional properties of Longmenshan fault zone at Shenxigou activated during the 2008 Wenchuan earthquake 被引量:3
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作者 Yu Wang Shengli Ma +7 位作者 Toshihiko Shimamoto Lu Yao Jianye Chen Xiaosong Yang Honglin He Jiaxiang Dang Linfeng Hou Tetsuhiro Togo 《Earthquake Science》 2014年第5期499-528,共30页
This paper reports internal structures of a wide fault zone at Shenxigou,Dujiangyan,Sichuan province,China,and high-velocity frictional properties of the fault gouge collected near the coseismic slip zone during the 2... This paper reports internal structures of a wide fault zone at Shenxigou,Dujiangyan,Sichuan province,China,and high-velocity frictional properties of the fault gouge collected near the coseismic slip zone during the 2008 Wenchuan earthquake.Vertical offset and horizontal displacement at the trench site were 2.8 m(NW side up)and 4.8 m(right-lateral),respectively.The fault zone formed in Triassic sandstone,siltstone,and shale about 500 m away from the Yingxiu-Beichuan fault,a major fault in the Longmenshan fault system.A trench survey across the coseismic fault,and observations of outcrops and drill cores down to a depth of 57 m revealed that the fault zone consists of fault gouge and fault breccia of about0.5 and 250-300 m in widths,respectively,and that the fault strikes N62°E and dips 68° to NW.Quaternary conglomerates were recovered beneath the fault in the drilling,so that the fault moved at least 55 m along the coseismic slip zone,experiencing about 18 events of similar sizes.The fault core is composed of grayish gouge(GG) and blackish gouge(BG) with very complex slip-zone structures.BG contains low-crystalline graphite of about 30 %.High-velocity friction experiments were conducted at normal stresses of 0.6-2.1 MPa and slip rates of 0.1-2.1 m/s.Both GG and BG exhibit dramatic slip weakening at constant high slip rates that can be described as an exponential decay from peak friction coefficient lpto steadystate friction coefficient lssover a slip-weakening distance Dc.Deformation of GG and BG is characterized by overlapped slip-zone structures and development of sharp slickenside surfaces,respectively.Comparison of our data with those reported for other outcrops indicates that the high-velocity frictional properties of the Longmenshan fault zones are quite uniform and the high-velocity weakening must have promoted dynamic rupture propagation during the Wenchuan earthquake. 展开更多
关键词 Wenchuan earthquake - Longmenshan faultsystem - Shenxigou fault zone Fault zone structures high-velocity friction
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Fine upper crustal structure of Jiashi strong earthquake swarm region in Xinjiang in-ferred from high resolution seismic refraction profile data
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作者 徐朝繁 张先康 +3 位作者 段永红 杨卓欣 鄷少英 胡修奇 《Acta Seismologica Sinica(English Edition)》 EI CSCD 2006年第1期62-71,共10页
The data obtained from a high resolution seismic refraction profile, which was carded out in Jiashi, Xinjiang, strong earthquake swarm area, were processed with both finite difference inversion and Hagedoorn refractor... The data obtained from a high resolution seismic refraction profile, which was carded out in Jiashi, Xinjiang, strong earthquake swarm area, were processed with both finite difference inversion and Hagedoorn refractor wavefront imaging technique and the fine upper crustal structure was determined. The results show that the upper crustal structure is relatively well-distributed in laterally and obviously by layers vertically.From surface to 11.0 km depth, there are about four layers. The P wave velocity of top two layers range from 1.65 to 4.5 km/s and their bottom boundaries, the buried depths of which are 0.4, 2.96-3.0 km respectively, are almost horizontal; The third layer is comparatively complicated and its P wave velocity presents inhomogeneous in both laterally and vertically. The bottom boundary of third layer is crystalline basement and shows a little uplift, which seemly suggest that the upper crust had been resisted while the hard Tarim block inserting into Tianshan Mountain; The forth layer is relatively even and its P wave velocity is about 6.3 km/s. There are a lateral velocity variation at the depth of about 4.0 km, and suggest that it has something to do with the hidden Meigaiti fault and Meigaiti-Xiasuhong fault but there are no the structure features about these faults stretching to the surface and passing through the crystalline basement. The seismogenic tectonic of Jiashi strong earthquake swarm at least lies in middle or lower crust beneath 11.0 km depth. 展开更多
关键词 Jiashi strong earthquake swarm region high resolution refraction finite different inversion Hagedoorn principle refractor wavefront imaging
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Synthetic sensitivity analysis of high frequency radiation of 2011Tohoku-Oki(MW9.0) earthquake
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作者 Haoran Meng Yongshun John Chen 《Earthquake Science》 2014年第4期355-364,共10页
Frequency-dependent rupture behavior of sub- duction zone interplate megathrust faults has been observed by back-projection method in different frequency bands (from 0.05 to 5 Hz). It has been suggested that the dow... Frequency-dependent rupture behavior of sub- duction zone interplate megathrust faults has been observed by back-projection method in different frequency bands (from 0.05 to 5 Hz). It has been suggested that the down-dip region of the Tohoku megathrust radiated strongly at high frequencies (〉10 Hz) compared with that of the up-dip region. By assuming the same source tirne function of each fault patch, we perform a synthetic sensitivity analysis to compare the energy received from the shallower parts (and further way from the receiver sites) with that frona the deeper parts (and closer to the receiver sites) of the rupture. Our results indicate that regional onshore recordings are probably not adequate to constrain the presence of far-off shore high frequency radiations because of the strong attenuation of this region. 展开更多
关键词 Tohoku-Oki earthquake - high frequencyradiation Frequency-dependent rupture behavior
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Preliminary analysis for the roles of crustal low-velocity and high-conductivity body in process of strong earthquake preparation 被引量:3
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作者 李炳乾 牛志仁 段锋 《Acta Seismologica Sinica(English Edition)》 CSCD 2000年第2期151-158,共8页
In this paper, the roles of low velocity and high conductivity body inside the crust in the process of strong earth quake preparation are approached by using theoretical analysis method based on the comprehensive rese... In this paper, the roles of low velocity and high conductivity body inside the crust in the process of strong earth quake preparation are approached by using theoretical analysis method based on the comprehensive researches on the fine structure of strong seismic source in the North China. The following results are obtained. The low-velocity and high-conductivity body plays the promoting role for the action of deep-seated structure in the medium stage of earthquake preparation, except that its existence is advantageous to the stress concentrating in the overlying brittle layer during the process of earthquake preparation. And it plays the triggering role for the occurrence of strong earthquake in the later stage of earthquake preparation. 展开更多
关键词 low-velocity and high-conductivity body strong earthquake preparation promoting function triggering function
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Measuring ground deformations caused by 2015 Mw7.8 Nepal earthquake using high-rate GPS data 被引量:1
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作者 Yong Huang Shaomin Yang +3 位作者 Xuejun Qiao Mu Lin Bin Zhao Kai Tan 《Geodesy and Geodynamics》 2017年第4期285-291,共7页
The April 25, 2015 Mw7.8 Nepal earthquake was successfully recorded by Crustal Movement Observation Network of China (CMONOC) and Nepal Geodetic Array (NGA). We processed the high-rate GPS data (1 Hz and 5 Hz) b... The April 25, 2015 Mw7.8 Nepal earthquake was successfully recorded by Crustal Movement Observation Network of China (CMONOC) and Nepal Geodetic Array (NGA). We processed the high-rate GPS data (1 Hz and 5 Hz) by using relative kinematic positioning and derived dynamic ground motions caused by this large earthquake. The dynamic displacements time series clearly indicated the displacement amplitude of each station was related to the rupture directivity. The stations which located in the di- rection of rupture propagation had larger displacement amplitudes than others. Also dynamic ground displacement exceeding 5 cm was detected by the GPS station that was 2000 km away from the epicenter. Permanent coseismic displacements were resolved from the near-field high-rate GPS stations with wavelet decomposition-reconstruction method and P-wave arrivals were also detected with S transform method. The results of this study can be used for earthquake rupture process and Earthquake Early Warning studies. 展开更多
关键词 high-rate GPS Mw7.8 Nepal earthquake Dynamic ground motion Permanent coseismic displacements P-wave arrival detection
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The Surface Rupture Zone and Coseismic Deformation Produced by the Yutian Ms7.3 Earthquake of 21 March 2008,Xinjiang 被引量:2
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作者 SHAN Xinjian QU Chunyan +5 位作者 WANG Chisheng ZHANG Guifang ZHANG Guohong SONG Xiaogang GUO Liming LIU Yunhua 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2012年第1期256-265,共10页
On 21 March 2008, a Ms7.3 earthquake occurred at Quickbird, Yutian County, Xinjiang. We attempt to reveal the features of the causative fault of this shock and its coseismic deformation field. Our work is based on ana... On 21 March 2008, a Ms7.3 earthquake occurred at Quickbird, Yutian County, Xinjiang. We attempt to reveal the features of the causative fault of this shock and its coseismic deformation field. Our work is based on analysis and interpretation to high-resolution satellite images as well as differential interferometric synthetic aperture radar (D-InSAR) data from the satellite Envisat SAR, coupled with seismicity, focal mechanism solutions and active tectonics in this region. The result shows that the 40 km-long, nearly NS trending surface rupture zone by this event lies on a range-front alluvial platform in Qira County. It is characterized by distinct linear traces and simple structure with 1-3-m-wide individual seams and maximum 6.5 m width of a collapse fracture. Along the rupture zone many secondary fractures and fault-bounded blocks are seen, exhibiting remarkable extension. The eoseismic deformation affected a large area 100~100 km2. D-InSAR analysis indicates that the interferometric deformation field is dominated by extensional faulting with a small strike-slip component. Along the causative fault, the western wall fell down and the eastern wall, that is the active unit, rose up, both with westerly vergence. Because of the big deformation gradients near the seismogenic fault, no interference fringes are seen on images, and what can be determined is a vertical displacement 70 cm or more between the two fault walls. According to the epicenter and differential occurrence times from the National Earthquake Information Center, China Earthquake Network Center, Harvard and USGS, it is suggested that the seismic fault ruptured from north to south. 展开更多
关键词 Yuntian earthquake high resolution image D-INSAR surface rupture zone coseismic deformation field
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Stress rise precursor to earthquakes in the Tibetan Plateau 被引量:2
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作者 Zhenhan Wu Qunce Chen +2 位作者 Patrick J. Barosh Hua Peng Daogong Hu 《Natural Science》 2013年第8期46-55,共10页
Earthquake prediction thus far has proven to be a very difficult task, but changes in situ stress appear to offer a viable approach for forecasting large earthquakes in Tibet and perhaps other continental regions. Hig... Earthquake prediction thus far has proven to be a very difficult task, but changes in situ stress appear to offer a viable approach for forecasting large earthquakes in Tibet and perhaps other continental regions. High stress anomalies formed along active faults before large earthquakes and disappeared soon after the earthquakes occurred in the Tibetan Plateau. Principle stress increased up to ~2 -?5 times higher than background stress to form high stress anomalies along causative faults before the Ms 8.1 West Kunlun Pass earthquake in November 2001, Ms 8.0 Wenchuan earthquake in May 2008, Ms 6.6 Nimu earthquake in October 2009, Ms 7.1 Yushu earthquake in April 2010 and the Ms 7.0 Lushan earthquake in April 2013. Stress near the epicenters rapidly increased 0.10 - 0.12 MPa over 45 days, ~8 months before the Ms 6.6 Nimu earthquake occurred. The high principle stress anomalies decreased quickly to the normal stress state in ~8 -?12 months after the Ms 8.1 West Kunlun Pass and the Ms 8.0 Wenchuan earthquakes. These high stress anomalies and their demise appear directly related to the immediate stress rise along a fault prior to the earthquakes and the release during the event. Thus, the stress rise appears to be a viable precursor in prediction of large continental earthquakes as in the Tibetan Plateau. 展开更多
关键词 earthquake Prediction high STRESS ANOMALIES In-Situ STRESS Measurement Large earthquakeS Seismic Fault TIBETAN PLATEAU
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Useful predictions ahead of large earthquakes and lessons learned for future progress 被引量:1
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作者 Ragnar Stefansson 《Geodesy and Geodynamics》 2020年第1期1-17,共17页
A significant basis for this article is the outcome of 4 multinational research projects which were carried out in South-West Iceland from 1988-2006,focusing on crustal processes that preceded two magnitude-6.6 earthq... A significant basis for this article is the outcome of 4 multinational research projects which were carried out in South-West Iceland from 1988-2006,focusing on crustal processes that preceded two magnitude-6.6 earthquakes in June 2000.The seismic activity that preceded a magnitude 6.3 double-earthquake in the same seismic zone in 2008 is also significant,as well as other research work which helps to understand how observable crustal processes lead to earthquakes.A significant outcome is that it cannot be assumed that any two earthquakes have the same precursory processes.Therefore,statistical analysis of precursors of past earthquakes is of limited value for predicting future earthquakes.On the other hand,with highly sensitive seismic monitoring it is possible to observe the nucleation process for each specific large earthquake for long enough time for earth-realistic modeling of it and extrapolating towards the earthquake in time and space.In the Iceland crust,with its fluid-rock interactions,pre-earthquake activity on a scale of years is expected.This allows a long-term approach to prediction.We apply historical information and sensor-based data to find probable sources of earthquake nucleation.We monitor the nucleation process for a possibly impending earthquake at these sources,and then model the process to find its governing factors and extrapolate those in time and space,aiming towards finding hypocenter,fault-size,impact,and time of the impending earthquake.We refine our models by predicting frequent medium-sized earthquakes and compare the predictions with measurements.We predict how the possibly impending large earthquake would trigger earthquakes at other locations.Given the complexity of the crust,we must take all observed changes into account when developing models of pre-earthquake processes.The development of a continuously operating geo-watching system is discussed to link scientific evaluations to warnings that can be used by emergency authorities. 展开更多
关键词 earthquake prediction UP-FLOW of high pressure FLUIDS Fluid-strain model Geo-watching system for WARNINGS
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Ascent schedules,acute altitude illness,and altitude acclimatization:Observations on the Yushu Earthquake 被引量:5
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作者 Wu Tianyi Hou Shike +2 位作者 Li Shuzhi Li Wenxiang Gen Deng 《Engineering Sciences》 EI 2013年第2期17-28,共12页
During the Yushu Earthquake on April 14,2010,a large number of rescuers from sea level or lowlands ascended to the quake areas very rapidly or rapidly less than 24 h. However,Yushu Earthquake is the highest quake in t... During the Yushu Earthquake on April 14,2010,a large number of rescuers from sea level or lowlands ascended to the quake areas very rapidly or rapidly less than 24 h. However,Yushu Earthquake is the highest quake in the world at altitudes between 3 750 m and 4 878 m where is a serious hypoxic environment. A high incidence of acute altitude illness was found in the unacclimatized rescuers;the mountain rescue operation changed as "rescue the rescuers". Lesson from the Yushu Earthquake is that the occurrence of acute altitude illness may be closely related to the ascent schedules. This prompted us to study the relationship between ascent rate and the incidence and severity of acute altitude illness;five different groups were compared. The first group was 42 sea level male young soldiers who ascended to quake area very rapidly within 8 h at 4 000 m;the second group was 48 sea level male young soldiers who ascended to 4 000 m rapidly less than 18 h;the third group was 66 acclimatized medical workers from 2 261 m who ascended to 4 000 m rapidly within 12 h;the fourth group was 56 Tibetan medical workers from 2 800 m who ascended to 4 000 m rapidly within 8 h;the fifth group was 50 male sea level workers who ascended to 4 000 m gradually over a period of 4 d. The results showed that the sea level rescuers ascended to 4 000 m very rapidly or rapidly had the highest incidence of acute mountain sickness (AMS) with the greatest AMS scores and the lowest arterial oxygen saturation (SaO2);the sea level workers ascended to 4 000 m gradually had moderate incidence of AMS with moderate AMS scores and SaO2 values;whereas the acclimatized and adapted rescuers had the lowest incidence of AMS,lowest AMS scores and higher SaO2;especially none AMS occurred in Tibetan rescuers. AMS score is inversely related to the ascent rate (r=-0.24,p< 0.001). Additionally,acute altitude illness is significantly influenced by altitude acclimatization. The ascent rate is inversely re- lated to the period of altitude acclimatization whereas the time of perfect recovered from AMS is positively correlated to the time taken to acclimatize. Generally,the best means of preventing acute altitude illness is slow and gradual ascent to high altitude,as this allows time for establishing altitude acclimatization and tolerance to the hypoxic environment. However,during an emergency circumstance,such as mountain rescue operation,the rescuers must rapidly ascend to high altitude,so a series of preventive strategies including pre-acclimatization,using some prophylactic drugs and oxygen supplementary are sorely necessary. 展开更多
关键词 Yushu earthquake ascent rate acute altitude illness high altitude acclimatization preventive strategies
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Variation of gravity before the Alxa Zuoqi M5.8 earthquake 被引量:1
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作者 Jianlin Feng Jin Wei +3 位作者 Yujuan Tan Jianzeng Qin Bangwu Huang Ruyi Xie 《Geodesy and Geodynamics》 2016年第4期295-301,共7页
In this study, a classic survey adjustment computation method was used for data obtained in the Inner Mongolia and Ningxia gravimetric networks between September 2013 and April 2015 so as to investigate the variation ... In this study, a classic survey adjustment computation method was used for data obtained in the Inner Mongolia and Ningxia gravimetric networks between September 2013 and April 2015 so as to investigate the variation of gravity before the Alxa Zuoqi M5.8 earthquake. The relationship between gravity variation and the Alxa Zuoqi M5.8 earthquake was analyzed. The results showed that: (1) the severe variation in gravity field at the test sites before the Alxa Zuoqi M5.8 earthquake, as well as the subsequent accelerated rising, might be an earthquake precursor; (2) the Alxa Zuoqi M5.8 earthquake occurred at the turning point where the high-gravity gradient zone changed from the NE direction to NW. 展开更多
关键词 Repeated gravimetry Gravity variations Alxa Zuoqi M5.8 earthquake high gravity gradient belt
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Site amplification effects as an explanation for the intensity anomaly in the Hanyuan Town during the Wenchuan Mw 7.9 earthquake 被引量:5
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作者 Liu Hongshuai Bo Jingshan +2 位作者 Li Ping QiWenhao Zhang Yudong 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2016年第3期435-444,共10页
The Hanyuan Town is located approximately 200 km from the macro-epicenter of the great Wenchuan earthquake. However, it is within the only Intensity VIII zone, surrounded by a region of Intensity VI. The objective of ... The Hanyuan Town is located approximately 200 km from the macro-epicenter of the great Wenchuan earthquake. However, it is within the only Intensity VIII zone, surrounded by a region of Intensity VI. The objective of this study was to investigate this high-intensity anomaly with respect to the site amplifications in the Hanyuan Town. The base inputs were derived from the records at a nearby strong-motion station because no records were available from the town. The characteristics of the subsurface formations and their dynamic properties at a typical site in the town were obtained by drilling, field tests and laboratory tests. Seismic response and parametric sensitivity analyses of the site were conducted using Shake 91, and the results were compared with the provisions for rare earthquakes from the Chinese Code for Seismic Design of Buildings (GBJ11-89). The results showed that the average peak acceleration at the site during the Wenchuan earthquake is similar to the code-specified value under rare earthquakes, that the corresponding spectral accelerations for periods betwcen approximately 0.35 and 0.75 s are significantly stronger than those specified by the code and that the average amplification factor at the site is significantly higher than the mean value of the site class. These findings indicate that the high-intensity anomaly in the town was primarily caused by site amplification effects from the unique structure of the soil strata. 展开更多
关键词 Wenchuan earthquake Hanyuan Town high-intensity anomaly site amplification rare earthquake
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Quantitative Tectonic Markers of Large Coastal Earthquakes in Fujian, Guangdong, Taiwan and Hainan——with a Discussion of Qualitative Indicators
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作者 Bi Fuzhi Yuan Youshen Institute of Crustal Dynamics, State Seismological Bureau, Beijing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1997年第4期395-406,508-510,共15页
This paper expounds the quantitative tectonic indicators and some qualitative indicators of large earthquakes in the coast areas of Fujian, Guangdong, Taiwan and Hainan. The main quantitative indicators include uplift... This paper expounds the quantitative tectonic indicators and some qualitative indicators of large earthquakes in the coast areas of Fujian, Guangdong, Taiwan and Hainan. The main quantitative indicators include uplift amplitude of the Moho, Quaternary and Late Holocene coasts. The paper also gives a brief account of the research method on quantitative indicators of surface uplifted zones. Taiwan is a famous neotectonic zone and an area of large earthquakes in the world. There is only one large-earthquake area in each of Fujian, Guangdong and Hainan Provinces. Along the coast large earthquake areas there are certainly many remains of crustal activity. Among these remains, coast activity, taking the sea level as the accurate marker horizon, can determine not only the amplitude of coastal elevation and subsidence in a certain period, but also the cycle and rate of positive or negative movements. 展开更多
关键词 quantitative tectonic indicator of large earthquake uplift amplitude of the oho uplift amplitude of the Quaternary high beachrock cycle of coastal large earthquakes
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PROBABILITY MODEL AND SOLUTION ON EARTHQUAKE EFFECTS COMBINATION IN ALONG WIND RESISTANT DESIGN OF TALL-FLEXIBLE BUILDINGS 被引量:1
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作者 洪小健 顾明 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第5期627-636,共10页
A model on the earthquake effects combination in wind resistant design of high-rise flexible structures is proposed in accordance with the probability method. Based on the Turkstra criteria, the stochastic characters ... A model on the earthquake effects combination in wind resistant design of high-rise flexible structures is proposed in accordance with the probability method. Based on the Turkstra criteria, the stochastic characters of wind velocity, earthquake ground acceleration and excitations occurrence probability are taken into account and then the combination of the earthquake effects in structure wind resistant design is analyzed with the convolution approach. The results indicate that as for the tall flexible buildings whose lateral force is governed by wind loading, the maximum lateral loads verification with respect to the wind resistant design combined with earthquake effects may be more unfavorable compared with that in terms of the earthquake resistant design involving wind effects. 展开更多
关键词 high-rise structure wind loading earthquake effects COMBINATION Turkstra criteria
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Earthquake-induced collapse mechanism of two types of dangerous rock masses 被引量:3
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作者 Wang Wei Yuan Wei +1 位作者 Wang Qizhi Xue Kang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2016年第2期379-386,共8页
As the economy of China develops, an increasing number of key traffic projects have been undertaken in the west of China, where there are high, steep rock slopes. The collapse of dangerous rock masses, especially foll... As the economy of China develops, an increasing number of key traffic projects have been undertaken in the west of China, where there are high, steep rock slopes. The collapse of dangerous rock masses, especially following a strong earthquake, is one of common geological disasters known in rock slope engineering. Therefore, it is important to study the collapse mechanism of dangerous rock masses induced by an earthquake and the analysis approach of its stability. This study provides a simple and convenient method to determine the collapse mechanisms of two types of dangerous rock masses (i.e. cantilever and upright) associated with the definition and calculation of the safety factor, which is based on the flexure theory of a constant-section beam by combining with the maximum tensile-stress criterion to depict the process of crack propagation caused by seismic waves. The calculation results show that there are critical crack depths in each form of the dangerous rock masses. Once the accumulated depth of the crack growth during an earthquake exceeds the critical depth, the collapse will occur. It is also demonstrated that the crack extension amount of each step is not a constant value, and is closely associated with the current accumulated crack depth. The greater the cumulative crack depth, the more easily the crack propagates. Finally, the validity and applicability of the proposed method are verified through two actual engineering examples. 展开更多
关键词 dangerous rock mass earthquake-induced collapse cantilever beam theory safety factor high-steep rock slope
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Analysis of the Impact of Nepal's Giant Earthquake on China's Climate in 2015
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作者 Chen Zhaohui Xie Jiemin 《Meteorological and Environmental Research》 CAS 2016年第1期36-40,共5页
The situation of a great earthquake in Nepal from April to May in 2015 was described, and the abnormal atmospheric circulation and cli- mate when the great earthquake occurred were analyzed. Because of the great influ... The situation of a great earthquake in Nepal from April to May in 2015 was described, and the abnormal atmospheric circulation and cli- mate when the great earthquake occurred were analyzed. Because of the great influence of the great earthquake on the atmosphere, the atmos- pheric circulation and climate in the late stage of Nepal will be affected. The great earthquake had transient effects on China's climate. Firstly, tem- perature from the ground to high altitudes increased abnormally; secondly, after the occurrence of the great earthquake, extremely low pressure generated in the earthquake region, and cold and warm airflow converged, so that heavy rainfall occurred to the southwest of the plateau. Thirdly, it cut off southwesterly airflow transporting water vapor to regions south of the Yangtze River, so that hot and dry weather appeared in the regions in late April. Moreover, the great earthquake affected China's climate in a short term. Nepal's giant earthquake increased zonal circulation cell at lat- itudes, and the circulation cell could make subtropical high over Western Pacific strengthen and extend westward to control regions south of the Yan- gtze River, so that hot and dry weather appeared in regions south of the Yangtze River in summer. In the next year after the great earthquake oc- curred, the earthquake is conducive to the strengthening and maintaining of Meiyu zone in the Yangtze River basin, and large floods will appear easily in the Yangtze River basin. 展开更多
关键词 Giant earthquake Low pressure South Asia high Southwest monsoon China
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