应用地震层析成象技术研究深部速度结构

罗马尼亚Ｖａｎｃｅａ地震区是大陆上发生与板块磁撞和削减有关的中深部地震活动的地区之一。本文介绍了应用地震层析成象方法研究该地区深部速度结构成果。在研究中使用了地方和区域地震所记录的４３３个浅源和中部地震的到时资料反演求解深至２００ｋｍ的三维速度结构,在走时和射线路径的计算中利用了有效的三维射线跟踪技术,在反演中采用ＬＳＱＲ算法,高分辨率的地震层析图象揭示了速度结构的广泛不均匀性,结果表明,地震层析     

渭河断陷及邻近地区地壳S波速度图象

选取１０４～１１２°Ｅ,３２．５～３８°Ｎ区域内陕西、山西、河南、湖北、甘肃、宁夏等省区的区域地震台网１９８４～１９９３年的１９４６个天然地震的Ｓ波观测资料,用地震层析成像方法反演了渭河断陷及其邻近地区的地壳Ｓ波速度图象,其结果表明地壳深部Ｓ波速度结构的不均匀性与该区大地构造单元、断裂构造及地震活动密切相关     

香河-北京-涿鹿及其相邻地区壳幔构造与速度结构特征

通过对北西向的宁河—北京—涿鹿宽角反射／折射剖面西段测深资料的二维处理、计算以及综合解释研究,获得了该段壳幔速度结构和深部构造的基本特征。结果表明：不同区域的壳幔速度结构在纵向和横向上均具有明显的非均匀性,壳幔深部构造呈现明显的层状结构和东浅西深的倾斜状态,地壳厚度由香河以东的３２～３３ｋｍ向西至北京西部的西山山区、怀来南部以及涿鹿迅速加深至３９～４０ｋｍ,其中北京为３６．５ｋｍ左右,并且在香河的西侧存在着延伸至Ｍ界面的深断裂     

用折射波Sn走时反演渭河断陷及邻近地区的莫霍面速度

根据陕西及邻近省区地震台网的地震记录,利用莫霍面折射波Sn的走时资 料,重建了渭河断陷及邻近地区莫霍间断面的速度图像,并对方法的稳定性及结果的 可靠性进行了探讨。     

腾格里沙漠东南缘沙丘迎风坡风速变化的初步研究

对腾格里沙漠东南缘格状沙丘表面气流的观测结果表明,迎风坡风速的增加程度因坡成形态和原始气流的方向,强度而不同。迎风坡风速放大率介于１．０６～１．９１之间,且在格状沙丘主梁,主要与坡形系数和高度有关;在副梁随原始风入射角,坡形系数而变化,风速放大率对沙丘形态的影响主一要增加丘顶区域的输沙率和活动性,且因区域气流的方向和强度而不同,在横向气流条件下,其迎风坡随区域气流强度和增加而变缓,变长,在双向（斜     

A numerical study on response modification,overstrength, and displacement amplification factors for steel plate shear wall systems

Design recommendations for steel plate shear wall (SPSW) systems have recently been introduced into seismic provisions for steel buildings. Response modification (R), overstrength (Ω_o), and displacement amplification (C_d) factors for SPSW systems presented in design codes were based on professional experience and judgment. A numerical study has been undertaken to evaluate these factors for SPSW systems. Forty‐four unstiffened SPSW possessing different geometrical characteristics were designed based on the recommendations given in the AISC Seismic Provisions. Bay width, number of stories, story mass, and steel plate thickness were considered as the prime variables that influence the response. Twenty records were selected to include the variability in ground motion characteristics. In order to provide a detailed analysis of the post‐buckling response, three‐dimensional finite element analyses were conducted for the 44 structures subjected to the selected suite of earthquake records. For each structure and earthquake record, two analyses were conducted in which the first includes geometrical nonlinearities and the other includes both geometrical and material nonlinearities, resulting in a total of 1760 time history analyses. In this paper, the details of the design and analysis methodology are given. Based on the analysis results, response modification (R), overstrength (Ω_o), and displacement amplification (C_d) factors for SPSW systems are evaluated. Copyright © 2008 John Wiley & Sons, Ltd.     

大规模数值计算的层分布物理参数研究

随着计算机技术的飞速发展和地震台网的建设对大城市的地震动数值模拟变成可能。应用地质．地貌以及地球物理勘探等资料建立的三维层结构是保证地震动计算准确性的基础。提出并论证了关于三维层分布模型的建模思路和相关数据处理方法。据此所建立的三维模型符合研究目标区的实际情况,同时,所提供的方法还便于模型的修改和升级。     

利用区域数字化地震台网速度记录仿真加速度时程的研究与应用

研究了利用区域数字地震台网CTS1-EDASC24速度型甚宽频带地震仪和FBS3-EDASC24速度型宽频带地震仪的速度记录仿真加速度时程的有关技术与应用问题,其中包括：仿真方法的选取,仪器性能和仿真参数的分析,仿真加速度时程与SLJ100-GDQJⅡ加速度型强震仪记录结果的比较,福建及邻近地区所选用地震的仿真加速度时程（1998-07-2008-07）,仿真结果在合成场地设计地震波中的应用等方面,并提供了具体的应用算例。     

豫鲁冀交界区应力场动态演化特征与中强震孕育关系研究

对豫鲁冀交界区域小震震源机制解进行了研究,分析应力场动态演化过程,进而探讨应力场异常与其他反映孕震规律的物理量（中等地震演化、波速比异常）的关系,在此基础上对本区域中强震的孕育情况进行综合判定。     

Key elements of regional seismic velocity models for long period ground motion simulations

Regional 3-D seismic velocity models used for broadband strong motion simulations must include compressional-wave velocity (Vp), shear-wave velocity (Vs), intrinsic attenuation (Qp, Qs), and density. Vs and Qs are the most important of these parameters because the strongest ground motions are generated chiefly by shear- and surface-wave arrivals. Because Vp data are more common than Vs data, many researchers first develop a Vp model and convert it to a Vs model. I describe recent empirical relations between Vs, Vp, Qs, Qp, and density that allow velocity models to be rapidly and accurately calculated. The U. S. government reserves the right to retain a non-exclusive, royalty free license in and to any copyright.