地震台实用数据库软件的建立及应用

该软件主要用于地震台站的大量数据处理及行政管理，全部用关系式数据库ＤＢＡＳＥⅢ编写，在主菜单的控制下，根据各个工作性质及需要选择适合自己的子菜单。它主要包括两大部分：（１）台站行政管理系统，（２）观测资料管理系统，以及每部分下相应的分支。     

变刚度钢管混凝土短柱隔震装置的性能研究

本文对变刚度钢管混土短柱震的滞回收性进行了理论分析和试验验证。对装置的隔震作用以及耗能特性进行了讨论通过低周反复荷载试验,证了分析的正确性。同时,试验还证明,变刚度钢管混凝土短柱震装置能很好的地耗散能量,从而减小地震反应,作者认为,该是一种价格性能比较优越的隔震装置,在工程实践中将有广阔的应用与推广前景。     

Accounting for sparsely observed rainfall space—time variability in a rainfall—runoff model of a semiarid Tunisian basin/Prise en compte d'observations peu denses de la variabilité spatiotemporelle de la pluie dans une modélisation pluie—débit d'un bassin semi-aride Tunisien

Abstract

The management of water excesses and deficits is a major task in semiarid Mediterranean regions, where the variability of rainfall inputs is high at different time and space scales. Thus intense hydrometeorological events, which generate both potential resource and hazards, are of major interest. A simple method is proposed, with the example of the Skhira basin (192 km²) in central Tunisia, to account for the event space–time variability of rainfall in a rainfall–runoff model, in order to check its influence on the shape, magnitude and timing of resulting hydrographs. The transfer function used is a geomorphology-based unit hydrograph with an explicit territorial significance. Simulations made for highly variable events show the relevance of this method, seen as the first step of a downward approach, and its robustness with respect to the quality and the density of rainfall data.     

A revised approach to the UKIH method for the calculation of baseflow / Une approche améliorée de la méthode de l'UKIH pour le calcul de l'écoulement de base

Abstract

A revised approach to the calculation of baseflow using the method originally proposed by the United Kingdom Institute of Hydrology is presented. The revisions resolve two aspects of the method that lead to less than optimal results; that is, the calculation of values of baseflow that exceed the corresponding values of streamflow and the dependence of the calculated values on the origin of the five-day segmentation of the input streamflow data. The approach is illustrated using streamflow monitoring information that is typical for areas of southern Ontario, Canada, where baseflow is primarily the result of groundwater discharge.     

Shake table testing of un‐reinforced brick masonry building test model isolated by U‐FREI

This paper presents a detailed study on feasibility of un‐bonded fiber reinforced elastomeric isolator (U‐FREI) as an alternative to steel reinforced elastomeric isolator (SREI) for seismic isolation of un‐reinforced masonry buildings. Un‐reinforced masonry buildings are inherently vulnerable under seismic excitation, and U‐FREIs are used for seismic isolation of such buildings in the present study. Shake table testing of a base isolated two storey un‐reinforced masonry building model subjected to four prescribed input excitations is carried out to ascertain its effectiveness in controlling seismic response. To compare the performance of U‐FREI, same building is placed directly on the shake table without isolator, and fixed base (FB) condition is simulated by restraining the base of the building with the shake table. Dynamic response characteristic of base isolated (BI) masonry building subjected to different intensities of input earthquakes is compared with the response of the same building without base isolation system. Acceleration response amplification and peak response values of test model with and without base isolation system are compared for different intensities of table acceleration. Distribution of shear forces and moment along the height of the structure and response time histories indicates significant reduction of dynamic responses of the structure with U‐FREI system. This study clearly demonstrates the improved seismic performance of un‐reinforced masonry building model supported on U‐FREIs under the action of considered ground motions. Copyright © 2015 John Wiley & Sons, Ltd.     

Shaking table test and analysis method on ultimate behavior of slender base‐isolated structure supported by laminated rubber bearings

This paper describes the results of shaking table tests to ascertain the ultimate behavior of slender base‐isolated buildings and proposes a time history response analysis method, which can predict the ultimate behavior of base‐isolated buildings caused by buckling fracture in laminated rubber bearings. In the tests, a base‐isolated structure model weighing 192 kN supported by four lead rubber bearings is used. The experimental parameters are the aspect ratio of height‐to‐distance between the bearings and the shape of and the axial stress on the bearings. The test results indicate that the motion types of the superstructure at large input levels can be classified into three types: the sinking type; the uplift type; and the mixed type. These behaviors depend on the relationship between the static ultimate lateral uplifting force on the superstructure and the lateral restoring characteristics of the base‐isolated story. In the analysis method, bearing characteristics are represented by a macroscopic mechanical model that is expanded by adding an axial spring to an existing model. Nonlinear spring characteristics are used for its rotational, shear, and axial spring. The central difference method is applied to solve the equation of motion. To verify the validity of the method, simulation analysis of the shaking table tests are carried out. The results of the analysis agree well with the test results. The proposed model can express the buckling behavior of bearings in the large deformation range. Copyright © 2010 John Wiley & Sons, Ltd.     

Dynamic analysis on structures base-isolated by a ball system with restoring property

A computational model with its analysis method for base-isolated structures by a ball system with restoring property under seismic force is proposed in this paper, and the programs using numerical integration method and incremental harmonic balance method are developed. The analysis method is verified by shaking table test results of a three-storey masonry model. With these programs, the effect of some factors on the aseismic behaviour of base isolation system are analysed, and the comparison of seismic response between structures with and without base isolation is made. Results of both theory and test show that the above-mentioned base isolation system has apparent advantages over the traditional aseismic structures. © 1998 John Wiley & Sons, Ltd.     

Real-time on-line test for MDOF systems

This paper presents a test system for conducting on-line tests in a real time and a series of real-time on-line tests conducted to verify the effectiveness of the system. The proposed system is characterized by (1) use of a Digital Signal Processor (DSP) now readily available, (2) adoption of the C language to ensure easy programming, and (3) separation of response analysis and displacement signal generation to apply the system for tests with complex structures. To create displacement signals successively without being interrupted by the computation of equations of motion, extrapolation and interpolation procedures using present and past target displacements are developed. Base-isolated building models were chosen for the real-time on-line test. The effectiveness of the extrapolation and interpolation procedures was demonstrated through a series of real-time on-line tests applied to the models treated as SDOF structures. A five-storey base-isolated building model (treated as a six DOF structure) was tested for various ground motions, and it was verified that the system is able to simulate earthquake responses involving large displacements and large velocities. The number of DOFs that can be handled in the proposed system was investigated, and it was found that the system is capable of performing the test with reasonable accuracy for up to 10 DOF structures with a range of response frequency not greater than 3·0 Hz, or 12 DOF structures with a range of response frequency not greater than 2·0 Hz. Copyright © 1999 John Wiley & Sons, Ltd.     

变刚度隔震保护装置试验研究

通过在距离隔震层一定位移处设置由弹簧和与其串联的限位挡板组成的变刚度保护装置作为第二道防线,成功地进行了五层框架的变刚度隔震保护模拟地震振动台试验。理论分析和试验结果表明,变刚度隔震保护装置能有效改变结构动力特性,减小隔震层的变形,使之限制在允许的范围内。     

地震前兆资料的快速应用

陕西省地震局研制的一套软件解决了地震前兆数字化和大华北资料共享后的大量数据在分析预报中的快速应用问题。内容有“九五”、“十五”、模拟和大华北资料的下载、处理、保存、计算、统计和制图等功能。采取了简化操作、成批处理、自动成图等方法,有效地提高了分析速度,与Mapsis互相兼容,取长补短,能在20分钟内完成地震趋势会商前的准备工作,在震情分析中发挥了良好的作用。