建筑抗震构件中屈曲约束支撑结构研究新进展

详细介绍了近年来中国学者在屈曲约束支撑研究方面取得的研究成果，着重讨论了屈曲约束支撑构件（核心单元、约束机构、无黏结构造层）和整体抗震性能以及设计方法的研究现状。结果表明：屈曲约束支撑以其良好的耗能性能具有很好的发展潜力，屈曲约束支撑的适用范围不断拓展，结构形式更趋多样化，设计方法不断优化。     

昆明机场红土地层地下结构抗震模拟研究

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。     

Intercomparisons of land-surface parameterizations coupled to a limited area forecast model

The goal of the Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) is to improve the understanding of the interactions between the atmosphere and the continental surface in climate and weather forecast models. In PILPS Phase 4(b), selected schemes are coupled to the Limited Area Prediction System (LAPS) developed by the Australian Bureau of Meteorology. To facilitate the comparison of PILPS schemes' behavior within LAPS, a single mode of coupling is selected: explicit coupling. This type of coupling is more flexible and avoids most of the problems raised when interchanging the surface schemes. Exploratory tests are conducted. Initially, experiments are run in which the land-surface schemes use the same parameters as in their original host models. Then, in other runs, the most important surface parameters are set constant in an attempt to reduce the scatter amongst the schemes' results. In order to understand the impact of initialisation of soil moisture on the schemes' results some extreme cases (wet and dry) are performed. The partitioning between surface fluxes is studied as well as the soil moisture budget. Both regional and local results are analysed. Sensitivity between LSS is found in the precipitation field with rainfall over the Australian continent altering by about 20%, but no significant change is found in the net radiation. The scatter in the surface energy fluxes amongst the schemes is large (up to 300 W m⁻² locally, during the daytime peak) but is seldom affected by the choice of surface parameters. The dynamical range of flux partitioning between extremely dry and wet initialisation varies strongly amongst the schemes. Some major shortcoming with the BUCKET approach are seen in the re-evaporation of convective precipitation over dry land, in the very large evaporation from wet surfaces and the diurnal cycle of surface temperature.     

1994年9月16日台湾浅滩7.3级地震发震构造的讨论

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。     

Development of Seismic Risk Scenarios Based on a Hybrid Method of Vulnerability Assessment

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.     

Seismic Zoning of Croatia

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.     

Seismic quiescence before the M 7, 1988, Spitak earthquake, Armenia

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.