云南地区房屋建筑的震害矩阵

自1992年4月23日云南孟连西中缅交界6.7、6.9级地震始,地震部门对云南地区的破坏性地震进行了现场灾害调查和经济损失评估。1992~2003年,云南地区共发生50次破坏性地震,积累了丰富的震害资料。本文根据云南地区的主要建筑结构,统计分析了50次地震不同烈度区的破坏比、损失比和震害指数,给出了房屋建筑的震害矩阵。     

Historical seismicity, palaeoseismicity and seismic risk in Western Macedonia, Northern Greece

Western Macedonia, Northern Greece, was a seismically quiescent region for one or more centuries, and was regarded as a nearly aseismic, rigid block inside a broad zone of distributed continental deformation and faulting, and a region of minimum seismic risk. Consequently, the May 13, 1995 destructive earthquake (M = 6.6) which hit this assumed aseismic zone was a surprise for scientists, government and population.However, historical and archaeoseismic evidence, as well as coastal change data indicate that the assumed aseismic region of Western Macedonia has been affected in the last 2,000 years by at least seven, and possibly nine destructive earthquakes. One of these earthquakes occurred in circa 1700, and probably had the same epicentre with, but higher magnitude than the 1995 shock.The earthquake in circa 1700 is deduced from historical data and is modelled on the base of a swarm of church repairs which is explained as post-seismic recovery of the broader Kozani area: except for certain well known cases of towns or areas in which religious privileges were granted, large scale repairs or reconstruction of churches during the Ottoman period were possible only after Sultan's permissions, usually following earthquakes and other calamities.It can hence be concluded that some, at least, of the apparently aseismic regions inside broad zones of distributed seismicity are hit by stronger shocks, but with longer (200 years or more) recurrence intervals than their adjacent zones. Consequently, the seismic risk of the apparently aseismic regions is certainly not low, especially since relatively long periods of seismic quiescence lead to constructions vulnerable to earthquakes.     

场地地震运动特征及其对工程设施的影响

本文试图指出地震工程中尚未得到重视和研究的一个重要方面——场地波动特性对工程设施震害的决定性作用,而这种波动特性又取决于地震区场地的地质地形条件。 文中列举了一些地面震害的特性类型,它们表明场地在地震中以特定的形式作整体波动,因而地面上的工程设施也就屈从于同样的形式而产生破坏。这种运动形式和特点并不能用现有的地面(质点)运动反应分析方法进行解释和概括。因此,文章从波动场的概念和有关理论对列举的一些场地运动特征进行了初步分析和研究,并对相应的抗震问题提出了新的见解。      

山西破坏性地震的人员伤亡和地面破坏特征

山西是一个多地震的地区，有史料记载以来共发生81次破坏性地震，这些地震除了在地震区引起人员伤亡和建筑物破坏以外，还引起喷沙冒水、地裂地陷、滑坡和崩塌等地面破坏。根据山西地震造成的人员伤亡和地面破坏的资料，讨论分析了人员伤亡和地面破坏的分布特点以及与震级的关系，这些结果对地震灾害的预测预防很有意义。     

随机方法在地震烈度速报中的应用

我国地震监测台网间距大,很难实现大震发生时地震烈度分布图的快速编制.基于随机方法,利用历史小震数据反演地震动估计模型的参数,参考地震发生时获取的少量强震动数据,选取合适的震源参数,正演地震动场的分布.根据地震烈度与地震动参数的经验关系,实现地震烈度速报.本方法可以模拟大震的近断层地震动特征,对高烈度区的判断较目前常用的烈度速报方法更为合理.研究成果既可以用于首张烈度分布图的发布,还能够用于地震烈度的动态修正.     

华安汰内井水氡对闽台地震的映震特征差异性分析

通过华安汰内井水氡对1987年以来福建地区M_L4.5以上地震、 台湾地区M_S7.0以上地震的映震特征分析, 认为该井水氡对福建和台湾地区地震的映震特征具有一定的差异性, 其差异性表现为对福建地区的地震, 其异常特征一般表现为突跳及振荡, 且异常多发生在震前20天左右, 同时异常持续的时间也较短; 对台湾地区的地震, 其异常特征表现为高值异常且异常持续时间长, 异常多发生在震前11个月左右。 据此可以在华安汰内井水氡发生异常时对未来的发震地点做出较为准确的判断。     

The seismotectonic and macroseismic features of the Wenchuan (Sichuan) earthquake (<Emphasis Type="Italic">M</Emphasis><Subscript><Emphasis Type="Italic">S</Emphasis></Subscript> = 8.0) of May 12, 2008

A disastrous earthquake with a magnitude M _S = 8.0 (M _W = 7.9), in China called “the 5.12 Wenchuan earthquake,” occurred on May 12, 2008, in Sichuan province on the border between the Sino-Tibetan Mountains and the Sichuan depression. The instrumental epicenter was registered in the southeastern part of Wenchuan county, and the hypocenter depth was 14 km. As the strongest and most destructive earthquake within mainland China, it caused numerous human losses and destruction of buildings and infrastructure. The seismic effect from the main shock and aftershocks was felt in many counties, towns, and villages, though Sichuan province suffered the most. The maximum intensity of the shocks was estimated at 11 degrees, according to the Chinese macroseismic scale. In the process of source opening, from the southern part of Wenchuan county to the vicinities of Quingchuan, a seismic fault system with a total length up to 240 km out-cropped on the earth’s surface, confined to the Longmenshan fault belt. The seismic fault system disturbed the original ground, resulting in the collapse or damage to various constructions, such as buildings, homes, bridges, roads, etc. Fault offsets had a dextral strike-slip and thrust kinematic combination. The earthquake generated several tens of thousands of landslides, rockfalls, and debris flows. Many dammed ponds appeared in the epicentral zone due to the activation of landslides. Thus, the geological effects turned out to be the most destructive factor in this case. At the same time, the seismic intensity of surface shaking was abnormally low even in direct proximity to the seismic fault system. Usually it was no more than 7–8 degrees. This macroseismic phenomenon may turn out to be rather typical for many major earthquakes.     

Ancient destructive earthquakes in Chersonesus Taurica and their importance for a long-term seismic hazard assessment of the Southwestern Crimea region

Continuing the author’s earlier works, the signs of ancient destructive earthquakes in the southwest Crimea have been collected and analyzed. These signs are considered using archeoseismological method based on the data of multiannual archeological excavations at Chersonesus Taurica and agricultural hinterland around it (chora) separately on each period of total destruction, reconstruction and new construction, and on structures of different purposes and degrees of earthquake-resistance (defensive structures, large civil buildings, dwellings, fortified estates, necropolises, and burials). Indirect signs are also involved. Both direct and indirect signs unambiguously contribute to form the general scenarios of considerable destruction in the polis and its chora, with the disturbance of entire socioeconomic life, which occurred in 340(±20) and 105(±5) BC as a result of strong earthquakes with I = VIII–IX (on MSK-64 scale). Based on the results of earlier works on destructive earthquakes of a later historical period in mind, the seismic potential of the Sevastopol source zone has been estimated.     

震源机制类型对近场峰值加速度(PGA)分布的影响——以唐山和汶川震区为例

利用首都圈强震台网比较密集的数字地震记录,研究2003年4月发生在唐山震区的2次4级地震。利用布设在四川、甘肃、陕西的强震台网和临时强震台网的资料,研究2008年7月和8月发生在四川汶川的2次6级地震。得到正断层和走向滑动断层、逆冲断层和走向滑动断层的地震近场PGA分布的差异。结果表明,这种差异是显著的。不仅大震的PGA近场分布复杂,中小地震也是如此。经频谱分析发现,这种影响出现差异的地震波频率较低,城市化的建筑向高层大型发展,其自振周期相应较长。近直立走向滑动地震的PGA高值区沿断层对称分布,而正断层和逆断层则集中在断层上盘,这对于破坏性地震应急救援中力量、物资的投入有借鉴意义。     

重庆地震台地倾斜观测资料分析

分析了重庆地震台地倾斜观测资料,结合重庆辖区内10多年来的地震活动,提取地倾斜观测异常,为地震预测提供前兆参考。资料分析认为:对于发生在震中距为80~120km的5.0级以下地震,地倾斜观测地震异常少;5.0级以上的地震,地倾斜观测有异常记录,地震中期异常往往表现为震前几个月倾斜量的较大幅度变化,短期异常多数表现为震前差分值的低值变化(在均值附近变化,幅值较小,持续时间20d左右),部分表现为差分值震前突跳,临震异常主要是震前几天短周期波动变化。     

Response spectral attenuation relationships for Sumatran-subduction earthquakes and the seismic hazard implications to Singapore and Kuala Lumpur

Singapore and Kuala Lumpur, the capital of Malaysia, may well represent the classic examples of area with low seismic hazard but with high consequence. Both cities are located in a low-seismicity region of Southeast Asia, where active seismic sources are located more than 300 km away. Seismic designs have not been implemented in this seemingly low-hazard region though distant earthquakes in Sumatra had frequently shaken high-rise structures in the two cities. Several studies have been conducted to systematically assess the seismic hazards of Singapore and the Malay Peninsula. The present research particularly addresses issues in deriving a new set of attenuation relationships of peak ground acceleration (PGA), peak ground velocity (PGV) and response spectral acceleration (RSA) for the Sumatran-subduction earthquakes. To be relevant for the seismic hazard assessment of the remote metropolises, the derived attenuation relationships cover a long distance range from 150 to 1500 km. The attenuation relationships are derived using synthetic seismograms that account for source and path effects. The uncertainties in rupture parameters, such as stress drop, strike, dip and rake angles, have been defined according to the regional geological and tectonic settings as well as the ruptures of previous earthquakes. The seismic potential of the Sumatran subduction zone are high in the region from 2°N to 5°S as there has been no recurrence of great thrust events since 1861. A large event with M_w greater than 7.8 in this particular subduction zone may be capable of generating destructive ground motions in Singapore and Kuala Lumpur, even at a distance of 700 km.     

Expulsion of geopressured hydrothermal system along active faults and its relation to the occurrence of earthquakes in the Shinanogawa seismic belt,Japan

The 1995 Northern Niigata Earthquake (M 6.0) occurred at a shallow depth in the Niigata seismic gap. The anomaly areas in temperature, electrical conductivity and Cl- concentration of groundwater trend northeast as linear distribution in the epicentral area and are approximately coincident with the area of the seismic intensity 6 (JMA scale). The distributions of seismic intensity 6 and groundwater anomalies convincingly imaged the presence of a buried active fault beneath the epicentral area. The occurrence of this earthquake and the anomalies of groundwater were related to the expulsion of geopressured hydrothermal system (GHS). All epicenters of the destructive earthquakes along the Shinanogawa seismic belt are actually located in the buried active fault zones characterized by the areas of temperature and geochemical anomalies of groundwater. These earthquakes might have been triggered by the activity of GHS. The expulsion of GHS along an active fault in combination with the thermal softening of fault     

辽宁地区1509年4月21日和1552年10月27日地震考证

辽宁是历史地震资料比较缺乏的地区,深入研究历史疑难地震,尤其是确认一些破坏性地震,对补充已有的地震目录和开展地震预测及工程场地地震安全性评价有重要作用。在历史地震研究中认真考查,论证已有的地震史料是最主要的手段和方法。但是若能在此基础上,利用现代地震资料,按"地震重复"发生理论反推一些历史上可能存在的破坏性地震,也可以认为是对历史地震研究方法的一种补充。按照这一思路,本文在进一步分析地震史料的基础上,通过与现代地震活动图像和大地震震害现象的对比,确认辽宁地区1509年4月21日的地震是一次破坏性地震,并对1552年10月27日的地震做了讨论。     

Seismic Hazard Matrix of Buildings in Yunnan

Seismologists have begun to investigate the earthquake damage and assess the economic losses on the spot in the Yunnan area since the earthquakes with Ms6.7 and Ms6.9 that occurred on the boundary between China and Myanmar west of Menglian county, Yunnan Province, on April 23, 1992. From 1992 to 2003, 50 destructive earthquakes occurred in Yunnan, and large amounts of data on seismic hazard have been accumulated. With focus on the major building structures, the paper makes statistical analysis on the earthquake damage ratio, loss ratio and seismic hazard index in the areas with different seismic intensity of the 50 events, and presents the seismic hazard matrix of buildings for the Yunnan area.     

地震动参数与地震烈度的多元回归研究

建立合理的地震烈度与地震动参数之间的对应关系,在工程抗震及烈度速报中有着十分重要的作用,文中以美国加州3次破坏性地震和我国今年来6次地震中所获得的强震记录作为数据源,应用最小二乘法进行线性回归,得到了不同地震动参数与烈度间的相关性.经统计发现,在地面加速度峰值、标准累计绝对速度等12种描述地震动强度的参数中,各种参数在...     

An investigation on the ground motion parameters and seismic response of underground structures

Peak ground acceleration (PGA), frequency content and time duration are three fundamental parameters of seismic loading. This study focuses on the seismic load frequency and its effect on the underground structures. Eight accelerograms regarding different occurred earthquakes that are scaled to an identical PGA and variation of ground motion parameters with ratio of peak ground velocity (PGV) to PGA, as a parameter related to the load frequency, are considered. Then, concrete lining response of a circular tunnel under various seismic conditions is evaluated analytically. In the next, seismic response of underground structure is assessed numerically using two different time histories. Finally, effects of incident load frequency and frequency ratio on the dynamic damping of geotechnical materials are discussed. Result of analyses show that specific energy of seismic loading with identical PGA is related to the seismic load frequency. Furthermore, incident load frequency and natural frequency of a system have influence on the wave attenuation and dynamic damping of the system.     

井水位长周期事件记录及其机理的讨论

选择了几口具有代表性的观测井, 并对这些井孔在强震前记录到长周期波现象的特征进行了分析。从理论上对地震前的长周期事件给出了较为合理的解释, 认为地震前一些敏感井水位长周期事件可能反映了断层蠕动、静地震与慢地震、断裂的预扩展和地震成核等。井— 含水层系统像一个长周期地震仪, 它为记录到有价值的前兆低频波提供了最佳的频率响应范围。     

关于1861年金州6级地震震中位置讨论

本文通过清代历史文献资料考证和现场人物访问、地貌及震害地质调查,将原定于金州镇的1861年金州6级地震震中迁至新金县普兰店以东的惠屯附近,两地相距约42公里     

华东地区具有短期预测意义的特殊显著性地震事件识别

依据华东地区中强地震前的地震活动特点,初步提出“特殊显著性地震事件”SPE的概念及其可能的识别方法.具有前兆指示意义的SPE可划分为三类,三类SPE分别表达了主震前中小地震与主震之间的时空位置关系.I类SPE距主震时、空距离均较近,在一定程度上与“直接前震”具有相似之处;II类SPE距主震时间较近、而空间距离可能较远,但与主震之间有一定的构造联系,具有时间上的“信号地震”的意义.Ⅲ类必须首先通过地震活动性方法对可能的SPE进行筛选,之后通过比较其与之前在同一位置发生的一系列中小地震的地震波参数之间的差异,在一定程度上进一步确认其短期预测意义.华东6次中强地震震例的研究结果表明,当可能的SPE的单台波速比小于此前该区域长时期的均值、归一化尾波持续时间大于此前该区域长时期的均值以及振幅衰减系数与此前该区域长时期均值之差大于长时期均值的30％时,可进一步认定其短期前兆意义.