A series solution for surface motion ampli-fication due to underground group cavities: Incident P waves

Introduction In recent years some big cities in China commonly build subways in central urban areas to improve crowded surface transportation, and the subways usually are large-scale group cavities composed by two parallel cavities. Construction of large-scale group cavities will certainly affect the design ground motion near the cavities, and further affect seismic safety of the existing build-ings nearby. So it is of significance to estimate this effect on seismic design of the buildings. H…     

Study on rupture zone of the M =8.1 Kunlun Mountain earthquake using fault-zone trapped waves

The observation of the fault-zone trapped waves was conducted using a seismic line with dense receivers across surface rupture zone of the M=8.1 Kunlun Mountain earthquake. The fault zone trapped waves were separated from seismograms by numerical filtering and spectral analyzing. The results show that: a) Both explosion and earthquake sources can excite fault-zone trapped waves, as long as they locate in or near the fault zone; b) Most energy of the fault-zone trapped waves concentrates in the fault zone and the amplitudes strongly decay with the distance from observation point to the fault zone; c) Dominant frequencies of the fault-zone trapped waves are related to the width of the fault zone and the velocity of the media in it. The wider the fault zone or the lower the velocity is, the lower the dominant frequencies are; d) For fault zone trapped waves, there exist dispersions; e) Based on the fault zone trapped waves observed in Kunlun Mountain Pass region, the width of the rupture plane is deduced to be about 300 m and is greater than that on the surface. Foundation item: Joint Earthquake Science Foundation of China (201001). Contribution No. RCEG200305, Research Center of Exploration Geophysics, China Earthquake Administration.     

现代温馨舒适--浙医一院门诊楼的环境设计

良好的医院环境,不光是合理的平面和适度的空间就能形成的,还要由色彩、合适的装饰材料、绿化、水、智能设备、家具、标识、艺术品,甚至音乐等多种因素综合而成,它是技术和艺术创造的最终结果。浙医一院门诊楼运用各种手段,为病人创造了一个温馨、舒适的就医环境。     

水文变异的滑动F识别与检验方法

针对传统F检验法只能用于已知变异点的检验,而无法用于变异点的识别问题,本文提出了滑动F识别与检验法。该法首先利用传统F检验法对序列逐点进行检验,找出满足F计算值大于临界值的所有可能变异点,然后选择F计算值达到最大值的那一点作为最可能变异点。利用该法对潮白河水资源分区45年年径流量序列进行了分析,并从物理成因角度对该检验结果进行了确认。结果表明滑动F 识别与检验法具有较好的检验效果,检验结果可信度较高。     

Small-scale spatial variation of the stress field in the back-arc Aegean area: Results from the seismotectonic study of the broader area of Mygdonia basin (N. Greece)

In the present work a detailed seismotectonic study of the broader area of the Mygdonia basin (N. Greece) is performed. Digital data for earthquakes which occurred in the broader Mygdonia basin and were recorded by the permanent telemetric network of the Geophysical Laboratory of the Aristotle University of Thessaloniki during the period 1989–1999 were collected and fault plane solutions for 50 earthquakes which occurred in the study area were calculated with a modified first motions approach which incorporates amplitude and radiation pattern information. Fault plane solutions for the 3 main shocks of Volvi (23/05/78, M_W = 5.8 and 20/06/78, M_W = 6.5) and Arnaia (04/05/95, M_W = 5.8) events and the 1978 aftershock sequence were additionally used. Moreover, data from two local networks established in the Mygdonia basin were also incorporated in the final dataset.Determination of the stress field was realized by the use of the method of Gephart and Forsyth [Gephart, J.W., Forsyth, D.W., 1984. An improved method for determining the regional stress tensor using earthquake focal mechanism data: application to the San Fernando earthquake sequence: Jour. Geophys. Res., v.89, no. B11, p. 9305–9320] for the stress tensor inversion and the results were compared with independent estimates based on the calculation of the average moment tensor [Papazachos, C.B.,Kiratzi, A.A., 1992. A formulation for reliable estimation of active crustal deformation and its application to central Greece. Geophys. J. Int. 111, 424–432]. The obtained stress results show a relatively good agreement between the two approaches, with differences in the azimuth of the dominant extension axis of the order of 10°. Furthermore, comparison with independent information for the mean stress axes provided by the study of kinematics on neotectonic faults [Mountrakis, D., Kilias, A., Tranos, M., Thomaidou, E., Papazachos, C., Karakaisis, G., Scordilis, E., Chatzidimitriou, P., Papadimitriou, E., Vargemezis, G., Aidona, E., Karagianni, E., Vamvakaris, D. Skarlatoudis, A. 2003. Determination of the settings and the seismotectonic behavior of the main seismic-active faults of Northern Greece area using neotectonic and seismological data. Earthquake Planning and Protection Organisation (OASP) (in Greek)] shows a similar agreement with typical misfit of the order 10°. The stress inversion method was modified in order to select one or both nodal planes of the focal mechanism which corresponds to the “true” fault plane of the occurred earthquakes and was able to select a single fault plane in the majority of examined cases. Using this approach, the obtained fault plane rose diagrams are in agreement with results from various neotectonic studies. Moreover, several secondary active fault branches were identified, which are still not clearly observed in the field.     

关于地裂缝地质灾害的优势面分析

地裂缝的成因可以分为天然构造地裂、人为诱发地裂和复合成因地裂、地震断裂,抽水不均匀地面沉降伴生地裂和渗透变形地裂是最主要的地裂缝类型。地裂缝以构造地裂和构造地裂基础上由人为活动诱发现象为主,用优势面观点和方法分析和研究是可行的。根据优势面的原理,提出防灾和减灾的思路,指出地裂灾害预测和预警系统研究对分析、评估和减灾是最有效的手段。防治地裂缝的原则是针对性治理和顺应自然取代对抗,对策是注重避让与选址、引调地表水、做好结构设计和地基处理、制定相应的防灾区域管理法规。     

精密导线网平面位移监测应用与分析

本文综述了某个大型工程平面变形监测的情况,用严密导线网成功地测定了平面位移,监测精度优于±3mm。     

抚顺老虎台煤矿矿震震源机制的研究

利用１９８８－１９９５年６月间抚顺考虑台煤矿１００个矿震记录的５３４个Ｐ波初动方向数据和抚顺及周围地区１２０个天然地震记录的５２６个Ｐ波初动方向数据,用格点深度法分别计算出它们的综合断层面解的Ｐ、Ｂ、Ｔ轴并对其进行了对比分析。     

利用GIS实现区化扫面采样点地质代码自动识别

本文主要介绍利用ＧＩＳ对地质图进行数字化采集和编辑,填写每个区的地质属性信息,将区化扫面中涉及的采样点与区进行拓扑分析,从而完成采样点地质代码的自动填写。并介绍了处理过程中的技术难点,为今后化探扫面中地质代码的填写提供了新的方法。