The inversion of anelastic coefficient,source parameters and site respond using genetic algorithm

It gradually becomes a common work using large seismic wave data to obtain source parameters, such as seismic moment, break radius, stress drop, with completingof digital seismic network in China (Hough, et al, 1999; Bindi, et al, 2001). These parameters are useful on earthquake prediction and seismic hazard analysis.Although the computation methods of source parameters are simple in principle and the many research works have been done, it is not easy to obtain the parameters accurately. There are two factors affecting the stability of computation results. The first one is the effect of spread path and site respond on signal. According to the research results, there are different geometrical spreading coefficients on different epicenter distance. The better method is to introduce trilinear geometrical spreading model (Atkinson, Mereu, 1992; Atkinson, Boore, 1995; WONG, et al, 2002). In addition, traditional site respond is estimated by comparing with rock station, such as linear inversion method (Andrews, 1982), but the comparative estimation will introduce some errors when selecting different stations. Some recent research results show that site respond is not flat for rock station (Moya, et al, 2000; ZHANG,. et al, 2001; JIN, et al, 2000; Dutta, et al, 2001). The second factor is to obtain low-frequency level and corner frequency fromdisplacement spectrum. Because the source spectrum model is nonlinear function,these values are obtained by eye. The subjectivity is strong. The small change of corner frequency will affect significantly the result of stress drop.     

全站仪轴系补偿原理及检验方法探讨

全面阐述了全站仪的轴系补偿相关理论和实践，指出了我国检验规程的不足之处，提出了改进方法。     

空间数据质量相关问题探讨

阐述研究空间数据质量问题的必要性和重要性,进而依据GIS数据流程系统分析了产生数据质量问题的各种因素;并重点介绍了空间数据质量问题中基本的误差和不确定性分析方法以及常用的误差控制与校正方法。     

地形图扫描数字化精度分析

本文分析了地形图扫描数字化的误差来源，讨论了误差控制方法及质量控制指标，探讨了成果数据相对于地形原图的位置精度，具有一定实用价值。     

测量误差与测量不确定度表述方法的研究

研究了国家计量技术规范－－《测量不确定度评定与表示》（JJF1059－1999）与测量数据处理的误差理论的区别与联系。讨论了如何依照JJF1059－1999的规定，完整、准确地评价和描述测量结果。     

地图投影的最小二乘二元多项式拟合的误差估计

探讨了在地图投影的最小二乘二元多项式拟合中参考点的分布对拟合误差的影响,提出了一种基于矩阵的秩亏的方法来判断参考点是否在指定次数的二元多项式空间的代数曲线上,并导出在极小范数最小二乘意义下的拟合多项式的误差估计式,公式表明拟合误差和参考点的最小二乘误差无关。     

Simplified vibratory characterization of alluvial basins

For the analysis of seismic wave amplification, modal methods are interesting tools to study the modal properties of geological structures. Modal approaches mainly lead to information on such parameters as fundamental frequencies and eigenmodes of alluvial basins. For a specific alluvial deposit in Nice (France), a simplified modal approach involving the Rayleigh method is considered. This approach assumes a set of admissible shape functions for the eigenmodes and allows a fast estimation of the fundamental frequency of the basin. The agreement with other numerical results (Boundary Element Method) and experimental ones is fully satisfactory. The simplified modal method then appears as an efficient mean for the global vibratory characterization of geological structures towards resonance. To cite this article: J.-F. Semblat et al., C. R. Geoscience 335 (2003).     

饱水黄土隧道变形规律研究

新松树湾隧道位于饱和的砂粘土中,土体的稳定性极差,施工难度较大。为此,在隧道施工期间,通过土工试验、隧道收敛和围岩内部位移的现场监测、隧道变形的三维有限元仿真计算等手段,对该隧道的变形规律进行了系统研究,获得了大量试验数据。研究成果对隧道的施工组织和支护参数的确定起到了重要作用,为此类隧道的施工积累了经验。     

Empirical correlations of soil parameters based on Cone Penetration Tests (CPT) for Greek soils

This study presents the results of Cone Penetration Tests (CPT) and estimated correlations with the results of other in-situ tests (standard penetration test, cross-hole, seismocone) and laboratory tests (classification and undrained shear strength tests). These tests cover nearly all types of penetrable soils in Greece and, together with the formulation of empirical correlations, complement and improve on previous studies due to the significant number of CPT measurements.     

2002年7～8月海河流域面雨量预报的误差分析

对天津市气象台和河北省气象台在2002年7—8月的海河流域面雨量24h、48h预报进行了误差对比分析，列举了几种预报误差，并利用模糊数学中的综合评判法，计算了它们的模糊评分。结果表明：海河流域的面雨量预报有一定的可信度，把其作为水文模式的初值，有较高的利用价值；对于各气象台各自辖区内的预报，范围越小，预报越准确；在对面雨量预报效果的评估上，80％(或80)这一数值是客观、可信的。