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891.
892.
893.
昆明机场残积红土既是区域内重要的土地资源,更是各类工程建设的建筑地基,由于机场及临近区域内小江地震活动断裂带和普渡河断裂带地震活动频繁,使研究区处于较不稳定状态。本文采用MIDAS GTS有限元数值分析软件,利用动三轴试验所得出的结果,分别对昆明长水国际机场玄武岩残积红土、砂页岩残积红土地层下典型的地下结构进行了抗震模拟研究。所获得的研究成果,对红土分布区城市及村镇房屋建筑地基和地下空间结构抗震安全稳定性评价具有一定的指导意义和实用价值。 相似文献
894.
从台湾海峡与台湾浅滩的地貌特征、区域构造格局、海峡盆地形成历史、深部构造与断裂构造、震源机制解以及地震活动等方面论述了台湾浅滩7.3级地震的发震构造,认为北东东向澎湖—北港隆起南侧断裂(义竹断裂)是该地震的发震构造。 相似文献
895.
Development of Seismic Risk Scenarios Based on a Hybrid Method of Vulnerability Assessment 总被引:11,自引:5,他引:6
A hybrid methodology of vulnerability analysis is presented, involving elements from both empirical and theoretical methods. A model for correlating analytically calculated structural damage indices to loss (in monetary terms) is also proposed and calibrated against available statistical data. Probability damage matrices derived using this methodology are incorporated into a cost-benefit model tailored to the problem of estimating the feasibility of seismically rehabilitating the existing stock of reinforced concrete buildings in Thessaloniki, Greece. Losses calculated using the suggested procedure are found to be in good agreement with losses incurred during the 1978 Thessaloniki earthquake. The results of the present study also indicate that benefit/cost ratios for reinforced concrete buildings are quite low. Hence, it appears that a pre-earthquake strengthening programme is not economically justifiable. 相似文献
896.
The territory of Croatia and neighboring regions is divided into 17 seismic source zones, considering available seismological
and geological data. On this basis, seismic hazard elements (seismicity rate, maximum magnitude, b-value, probabilities of
exceedance and return periods for a predefined set of magnitudes) are computed using the maximum likelihood method appropriate
for treating data-sets with variable completeness thresholds. The values of long term expected peak horizontal acceleration
obtained by using a combination of the deterministic and the probabilistic procedure are the highest in the Dubrovnik zone,
while the Zagreb zone has the highest earthquake hazard in the continental part of the country.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
897.
898.
A detailed analysis of the 35 yr of seismicity between 1962 and 1997 using a gridding technique shows that the M 7, Spitak earthquake of 1988 December 7 was preceded by a quiescence anomaly that started at approximately 1984±0.5, and lasted about 5±0.5 yr, up to the main shock. This quiescence anomaly had a radius of about 20±3 km, estimated from circular areas with 75 per cent rate decrease, centred at the point of maximum significance of the anomaly. The quiescence was clearly present in the aftershock volume during the 5 yr before the 1988 main shock, but its statistically strongest expression was located 30 km NW of the epicentre. This anomaly fulfills the association rules between precursory quiescence anomalies and main shocks, even for a tight definition, and is therefore proposed as a case of precursory quiescence. The largest value of the standard deviate Z , found by random selection of samples by gridding, was Z =14 for a time window of T w =3 yr, using a sample size of N =300 events. This makes this anomaly the strongest observed so far, and it is the first documented in an environment of continental collision. There are no false alarms exceeding in significance the precursor. The Armenian earthquake catalogue used for this study had 4600 earthquakes with M ≥ M min =2.2 in the area bounded by 39.5° to 42°N/42.5° to 47°E. From the point of view of homogeneous reporting this is the best catalogue we have analysed so far. The limits of the data used and the density of the grid are dictated by the data, and have no influence on the results. The choice of free parameters does not influence the results significantly within the following limits: 100≤ N ≤500, 2≤ T w ≤7, 2.2≤ M min ≤2.8. 相似文献
899.
900.