宝鸡簸箕山滑坡地震勘探

宝鸡簸箕山滑坡是宝鸡市区的一个大型滑坡,危及许多市民及建筑的安全。为进一步了解滑坡体的细微结构及其滑面形态,中奥双方于1999年和2000年两次对簸箕山滑坡进行了地震勘探。本文详细介绍了地震勘探测线布设、各条测线的勘探及分析、解释结果,为该滑坡的科学治理提供了背景性参考资料。     

古代生物分子在第四纪研究中的应用

从第四纪化石和沉积物中获得的古代生物分子为第四纪研究者提供了丰富和独特的有关古代生物、遗传和古环境信息的定量和高分辨率的数据.过去10多年的研究证实来自第四纪材料中的各种古代生物分子的分离、鉴定和应用的能力在不断增加.文章总结了古代生物分子在第四纪研究中的最新进展,主要包括以下几个方面的内容:1)不同类型的古代生物分子在地质体中的保存和降解;2)古DNA和古蛋白序列中的生物遗传学信息;3)单体分子同位素与第四纪古环境和古气候研究;4)建于古代生物分子水平上的第四纪年代学.作者预见对第四纪地层中的原位和分散保存的古代生物分子的研究将在广度上以多分子综合研究而深度上与单体分子同位素技术相结合,为第四纪科学家们提供大量解决地质学和演化生物学问题的高精度数据.随着地球化学和分子生物学技术的不断改进以及人们对古代生物分子的降解过程和机制的进一步理解,对古代生物分子的研究无疑将进一步促进和推动第四纪科学研究的发展.     

Introduction of structural aseismic research in China in recent four years

Introduction Greeting the coming of the 21st century, Professor HU Yu-xian and other Chinese scholars briefed the trend of earthquake engineering in China and aboard (HU, 1999; HU, ZHOU, 1999). The experiences and lessons learning from the destructive earthquakes in China and abroad in re-cent years, the damage action of the large velocity impulse in ground motion in near field in seis-mic design, numerous earthquake examples show that there are many weaknesses in aspects of earthquake p…     

Scattering of elastic waves by a general anisotropic basin. Part 2: a 3D model

Scattering of plane harmonic waves by a three‐dimensional basin of arbitrary shape embedded within elastic half‐space is investigated by using an indirect boundary integral equation approach. The materials of the basin and the half‐space are assumed to be the most general anisotropic, homogeneous, linearly elastic solids without any material symmetry (i.e. triclinic). The unknown scattered waves are expressed in terms of three‐dimensional triclinic time harmonic full‐space Green's functions. The results have been tested by comparing the surface response of semi spherical isotropic and transversely isotropic basins for which the numerical solutions are available. Surface displacements are presented for a semicircular basin subjected to a vertical incident plane harmonic pseudo‐P‐, SV‐, or SH‐wave. These results are compared with the motion obtained for the corresponding equivalent isotropic models. The results show that presence of the basin may cause significant amplification of ground motion when compared to the free‐field displacements. The peak amplitude of the predominant component of surface motion is smaller for the anisotropic basin than for the corresponding isotropic one. Anisotropic response may be asymmetric even for symmetric geometry and incidence. Anisotropic surface displacement generally includes all three components of motion which may not be the case for the isotropic results. Furthermore, anisotropic response strongly depends upon the nature of the incident wave, degree of material anisotropy and the azimuthal orientation of the observation station. These results clearly demonstrate the importance of anisotropy in amplification of surface ground motion. Copyright © 2003 John Wiley & Sons, Ltd.     

Inelastic dynamic analysis of RC bridges accounting for spatial variability of ground motion,site effects and soil–structure interaction phenomena. Part 1: Methodology and analytical tools

During strong ground motion it is expected that extended structures (such as bridges) are subjected to excitation that varies along their longitudinal axis in terms of arrival time, amplitude and frequency content, a fact primarily attributed to the wave passage effect, the loss of coherency and the role of local site conditions. Furthermore, the foundation interacts with the soil and the superstructure, thus significantly affecting the dynamic response of the bridge. A general methodology is therefore set up and implemented into a computer code for deriving sets of appropriately modified time histories and spring–dashpot coefficients at each support of a bridge with account for spatial variability, local site conditions and soil–foundation–superstructure interaction, for the purposes of inelastic dynamic analysis of RC bridges. In order to validate the methodology and code developed, each stage of the proposed procedure is verified using recorded data, finite‐element analyses, alternative computer programs, previous research studies, and closed‐form solutions wherever available. The results establish an adequate degree of confidence in the use of the proposed methodology and code in further parametric analyses and seismic design. Copyright © 2003 John Wiley & Sons, Ltd.     

Inelastic dynamic analysis of RC bridges accounting for spatial variability of ground motion,site effects and soil–structure interaction phenomena. Part 2: Parametric study

The methodology for dealing with spatial variability of ground motion, site effects and soil–structure interaction phenomena in the context of inelastic dynamic analysis of bridge structures, and the associated analytical tools established and validated in a companion paper are used herein for a detailed parametric analysis, aiming to evaluate the importance of the above effects in seismic design. For a total of 20 bridge structures differing in terms of structural type (fundamental period, symmetry, regularity, abutment conditions, pier‐to‐deck connections), dimensions (span and overall length), and ground motion characteristics (earthquake frequency content and direction of excitation), the dynamic response corresponding to nine levels of increasing analysis complexity was calculated and compared with the ‘standard’ case of a fixed base, uniformly excited, elastic structure for which site effects were totally ignored. It is concluded that the dynamic response of RC bridges is indeed strongly affected by the coupling of the above phenomena that may adversely affect displacements and/or action effects under certain circumstances. Evidence is also presented that some bridge types are relatively more sensitive to the above phenomena, hence a more refined analysis approach should be considered in their case. Copyright @ 2003 John Wiley & Sons, Ltd.     

松辽盆地南部十屋断陷古构造对营城组扇三角洲发育的控制

在恢复古构造的基础之上，对比了松辽盆地南部十屋断陷营城组沉积时期的古构造格局与现令构造格局的异同。古构造对扇三角洲沉积体系的控制作用主要表现在：(1)主要基底断裂控制了扇三角洲的展布方向；(2)倾向与物源方向相反的断层和古地貌阻滞了扇三角洲的展布；(3)沉降中心控制了扇三角洲前缘的纵向叠置和发育。     

大同市区二十年地下水动态研究

本文首先分析了大同市地下水开采与地下水降深之间的对应关系，同时分析了影响地下水动态的其它因素，然后将地下水开采和大气降水量这两个影响地下水动态的主要因素与地下水动态进行复相关计算，求出相关方程，并进行不同开采量的地下水降深预测，最后根据这些地下水动态研究结果提出了解决大同市水问题几项对策建议。本文的研究结果同时表明，地下水动态研究非常必要且现实意义明显。通过动态变化可以了解地下水的补排及储水介质的变化情况，利用动态变化规律可以预测水文地质条件的变化趋势，根据地下水动态变化特点可采取有针对性的、灵活的取水方案。可以说，地下水动态研究成果在水资源的开发、利用、保护中具有极大的可利用价值。     

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.     

招远市金矿区环境遥感调查研究

以遥感图像为基本数据源,以实地调查数据为样点,建立解译标志,利用遥感和地理信息系统新技术对金矿区地质环境条件进行研究,实现航片与卫片校正、地质环境信息的解译、空间数据库的建立.为恢复矿区自然环境提供准确、详实的资料.