共查询到20条相似文献，搜索用时 125 毫秒
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邱国荣 《地震地磁观测与研究》1992,13(2):61-66
文章根据长周期地震观测的理论和我国763长周期台网的观测实践,分析了长周期观测中的环境干扰。认为长周期观测对环境干扰(主要指温、湿度)敏感,但影响长周期仪器正常工作的关键是潮湿,尤其是记录室的潮湿。文章以763台网优秀台站的观测实践为例,认为只要掌握了环境干扰的规律,在防潮问题上采取有效措施,长周期地震观测是完全可以做到仪器工作稳定,管理得心应手。 相似文献
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李盛祥 《地震地磁观测与研究》1995,16(3):74-76
地磁记录室的防潮问题研究李盛祥（中国四川６３００５６重庆地震台）潮湿问题至今仍困扰着我国的地磁记录（含部份观测）工作。潮湿的来源有几个方面：一是地下水汽或地下水冲破记录室的地下防线，升腾或渗透进入室内；二是施工过程中残留在室内建材及空气中的水份及水汽... 相似文献
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近年，我国建立了大批的数字化地震台站，数字地震观测正逐渐取代模拟观测。而其地震计因采用电子反馈技术及其较宽的频带等，容易受到潮湿、气流扰动、温度变化等因素的影响，使地震记录产生无规则的漂移，尤其是仿真中长周期后更明显。为解决这些问题，本文介绍一种用于FBS-3A型地震计的保温防潮防护罩的设计制作原理，鹤岗地震台实际使用后效果显著。 相似文献
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IAGA(国际地磁学和高空大气学协会 )在《地磁测量与地磁台站工作指南》中指出 ,“对放置新型磁变仪的场所有 3点主要要求 :放探头用的稳定的墩子 ,稳定的温度和无磁性的建筑材料” (周锦屏等 ,1 999)。数字地磁记录仪器的应用在许多国家已有多年历史 ,IAGA的总结对我国地磁台站磁通门记录室的建设或改造具有重要的指导意义。成都地磁台相对记录室曾采用珍珠岩颗粒夹层、加厚薄弱墙等保温措施及氯化钙防潮措施对于地下水位浅、空气湿度大的地面建筑的地磁房收到了良好的保温防潮效果。由于珍珠岩颗粒年久要缩塌 ,对保温的长期效果有一定… 相似文献
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磁变仪保温与防潮 总被引：1，自引：0，他引：1
朱贤长 《地震地磁观测与研究》1991,12(4):63-65,62
我国各地磁台站的相对记录仪器,目前仍然使用磁变仪。而温度和潮湿是影响仪器正常工作的两大因素。怎样尽量减少这些因素对仪器产生的影响,提高观测资料的内在质量?本人通过十多年台站工作实践,有一些想法在此和大家一起讨论,希望能够起抛砖引玉的作用。 相似文献
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目前,地震系统观测使用的仪器,或多或少的受温度或环境干扰。为了避免这一现象,不少地震台站将有关仪器安装在人防坑道或山洞内。这样做的好处是常年恒温并能克服地面干扰,但是,会伴有潮湿问题。仪器由于长期受潮,灵敏度降低,故障率猛增,甚至仪器报废。为了解决这一矛盾,经多年实验,对部分地震仪器进行了局部密封,较好地解决了仪器受潮的问题。 相似文献
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Seismic upgrading of old masonry buildings by seismic isolation and CFRP laminates: a shaking-table study of reduced scale models 总被引：2，自引：2，他引：0
The efficiency of improving the seismic resistance of old masonry buildings by means of seismic isolation and confining the
structure with CFRP laminate strips has been investigated. Five models of a simple two-story brick masonry building with wooden
floors without wall ties have been tested on the shaking table. The control model has been built directly on the foundation
slab. The second model has been separated from it by a damp-proof course in the form of a PVC sheet placed in the bed-joint
between the second and the third course, whereas the third model has been isolated by rubber isolators placed between the
foundation slab and structural walls. Models four and five have been confined with CFRP laminate strips, simulating the wall
ties placed horizontally and vertically at floor levels and corners of the building, respectively. One of the CFRP strengthened
models has been placed on seismic isolators. Tests have shown that a simple PVC sheet damp-proof course cannot be considered
as seismic isolator unless adequately designed. Tests have also shown that the isolators alone did not prevent the separation
of the walls. However, both models confined with CFRP strips exhibited significantly improved seismic behavior. The models
did not collapse even when subjected to significantly stronger shaking table motion than that resisted by the control model
without wall ties. 相似文献
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用Pg波走时重建华北地区结晶基底速度及时间项图像 总被引：3，自引：0，他引：3
应用层析成象以投影方法，对华北地区２８条深地震剖剖面地震测深剖面Ｐｇ波走时进行处理，作出该区结晶基底速度及时间项成像。并作了方法的数值模型合成数据的敏感性分析，证明所采用有效性及成象结果的可靠性。计算中应用ＬＳＱＲ算法求解大型稀疏超定方程。并采用只存储矩阵非零元素技术，使存储量减小到原矩阵百分之一，同时零元素不参数加计算，提高了运算速度。华北地区结昌基底速度为５．９－６．３５ｋｍ／ｓ，时间最大为２ 相似文献
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砌体结构抗震抗剪强度分析 总被引：9，自引：0，他引：9
进行了墙体抗剪强度理论和公式的研究。将主拉强度理论与剪摩强理论相结合,形成了一种新和强度理论,即拉摩强度理论。根据该理论,导出了墙体抗剪强度公式。给出了公式系数的确定方法,并确定了砖墙体的公式系数。将本文建议的砖墙体抗剪强度公式与抗震和砌体规范采用的抗剪强度公式进行了比较,比较结果表明：抗震规范公式值较小;砌体规范公式值较在,本文公式值介于两者中间。 相似文献
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地震作用下储罐与管道连接波纹管的动力响应 总被引：2，自引：2，他引：2
针对储罐与管道连接这个抗震薄弱环节进行研究，考虑了储罐与地基、管道与地基的相互弹性作用及流固耦合作用，使计算模型比较符合工程实际情况。将储罐罐壁看作为刚体，将波纹管部分和管道部分分别用旋转锥壳单元和空间梁单元离散化，通过分析得到波纹管与储罐连接接合面、波纹管与管道连接接合面不同单元之间的位移协调约束方程，并用罚函数法进行处理。根据流体力学速度势理论和有限元法的基本理论，利用哈密尔顿变分原理推导出储罐与管道连接波纹管系统动力分析方程，编制了系统动力分析有限元程序，计算了垂直地震激励不同场地土地基条件下储罐与管道连接波纹管位移响应。 相似文献
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北京时间2013年1月29日,哈萨克斯坦发生MS6.1地震,为了提高对地震震源机制解的认识,并进一步了解震源区的应力场特征,利用CAP方法反演了此次地震序列震源机制解.反演结果表明,MS6.1地震节面Ⅰ的参数：走向241°,倾角80°,滑动角7°;节面Ⅱ的参数：走向150°,倾角84°,滑动角170°;P轴方位为196°,倾角2°,T轴方位为105°,倾角12°;矩震级MW为6.1;矩心深度为13km;震源类型是左旋走滑型.此次地震序列破裂优势方向为NEE—SWW,倾角以30°～60°居多,滑动角以60°～120°、-60°～-120°居多;P轴方位的优势取向为近NE—SW向,接近水平的居优;T轴优势取向为近SEE—NWW向,接近垂直的居优;震源机制类型以倾向滑动型为主.反演结果与断层的分布、余震分布及哈萨克斯坦中天山（伊犁盆地西部）NEE—SWW向应力场有很好的一致性. 相似文献
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等效框架模型采用宏观模型来模拟砌体墙在平面内的抗震性能。砌体墙的墙柱和墙梁采用同时考虑轴向弯曲和剪切变形的基于力法的纤维截面进行模拟,且两者的连接视为刚性区域。轴向压缩及弯曲效应在截面纤维模型中考虑,而剪切效应由V-γ剪切恢复力模型表达,弯曲和剪切在单元层面进行耦合。通过统计和分析,确定骨架曲线的计算方法,并基于Ibarra-Krawinkler模型提出剪切恢复力模型。通过算例得出:该模型在单调加载和循环加载下的数值计算结果与试验结果均吻合较好。 相似文献
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Enrique Gómez-Treviño Francisco Javier Esparza Hernández José Manuel Romo Jones 《Geofísica Internacional》2013,52(2):135-152
The series and parallel impedances of the magnetotelluric tensor are appraised in relation to their relative immunity to galvanic electric distortions. The distorted responses are modeled using the Groom-Bailey decomposition of the tensor in terms of twist, shear, statics and strike direction. These four parameters and the undistorted responses are normally considered as unknowns, and are obtained from field data through the solution of an inverse problem. In the present work we use the decomposition as a forward model to simulate distorted sounding curves. Starting with undistorted 2-d te and tm responses, the tensor is distorted by assuming arbitrary values of twist, shear, static and strike direction. By default, both series and parallel responses are immune to the strike direction because they are invariants under rotation. In addition, series responses are immune to twist and shear and parallel responses only to twist. The dependence of the latter on shear is in the form of a real factor that shifts downwards the amplitude curves. On the other hand, the effect of statics on both series and parallel responses is more complicated than that on the impedance tensor because it cannot be accounted for by a simple shift of the curves. On the whole, there is a positive balance on the part of the series and parallel impedances over the te and tm responses because some of the distortions are filtered out by the invariants. It is shown that invariance is not sufficient to be immune to any of the distortions. The example chosen is Eggers’ eigenvalues, which are immune only to the by-the-fault strike direction. Invariance is not necessary either, as evidenced by the phase tensor, whose elements depend on strike but are immune to all distortions. The derivations are illustrated using soundings from the synthetic coprod2s1 and field-recorded coprod2 and bc87 data sets. 相似文献
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The generalized Rayleigh type surface waves are studied in a multilayered medium consisting of anisotropic poroelastic solid
layered stack beneath a fluid layer and overlying a heterogeneous elastic solid half-space. The heterogeneity, considered,
is of vertical type. The interface between solid layer and half-space is treated as an imperfect interface and suitable boundary
conditions are applied thereat. The technique of transfer matrix is used to obtain the dispersion equation in compact and
convenient form. Numerical results are obtained for particular models. The effects of anisotropy and heterogeneity on the
surface waves speed are discussed. 相似文献