台湾海峡及其西边地区正常地震动态及危险性特征

本文从地震的时，空分布特征，区域应力场动态，能量释放方式，ｂ值及震群特征６个方面研究了台湾海峡及其西边地区地震活动的正常动态及异常特征。结果表明，具有前兆意义的变化模式表现为区域地震活动在时间，空间及功能方面的有序性变化，即：（ａ）地震空间分布由分散转为集中，形成条带或空区；（ｂ）断裂活动由多组转为单一，应力场趋向一致；（display status     

Risk Assessment for Tuzla Naval Base Breakwater

1 .IntroductionTurkeywasstruckbytwomajorearthquakeeventsonAugust 1 7thandNovember 1 2th ,1 999,namedIzmit (Mw=7.4 )andD櫣ｚｃｅ (Mw=7.2 )earthquakes,respectively .ThestationsoperatedbytheGeneralDirectorateofDisasterAffairs,theKandilliObservatoryandEarthquakeResearchInstituteofIstanbulTechnicalUniversitymeasuredatleast 2 7stronggroundmotionsfortheIzmitearthquakewithin 2 0 0kmofthefault.AsignificantsegmentofthefaultrupturedintheareabetweenthewestofGolcukandtheeastofLakeSapanca .Inthesou…     

Study on Key Technology of Using Shell Sand as Backfill for Sea Reclamation

1 .IntroductionEpicontinental sea or land could formfromcontinental shelf because of the decreasing sea levelduring Quaternary.There is a large-area shell sand deposit more than ten meters thick in the neriticzone of China .To use the abundant marine shell sandresource as engineering material for ocean engi-neering and port engineeringis veryimportant .Sand (Gred and Bjorn,1999) ,fine sand (Zhangetal .,2002) , mediumand coarse sand (Qiuet al .,1995) ,highly weathered stone ballast (Zhanetal…     

"5.12"汶川大地震震中区映秀镇地震灾情及次生地质灾害遥感初步调查

"5.12"四川汶川8级大地震发生后,中国国土资源航空物探遥感中心立即采用"赛斯纳"高空遥感飞机,携带高清晰彩色数码相机及先进的POS系统,迅速获取了重灾区的航摄图像数据。本文以震中附近的映秀镇地区为例,简要介绍了以该高质量航摄数据为基础,采用数字滑坡技术,快速进行震后重灾区灾情及次生地质灾害遥感调查的成果。     

高地震区公路隧道地震动力响应分析

基于土一结构相互作用理论,对高地震区一实际重大工程的公路隧道洞口段结构进行了抗震计算,得到了衬砌结构各控制点的位移、加速度及内力响应规律。结果表明：在人工合成地震波条件下,衬砌墙脚、拱腰为抗震薄弱位置;结构的加速度波形与输入波形相似;这些结果为抗震设计提供了一些依据。     

研究“源兆”的若干问题及途径分析

从位场理论的观点讨论了场和源的概念,建议将“场兆”改称为构造前兆,将“源兆”称为震源前兆。文中还分析了震源体与各种前兆观测方法探测的深度,并根据地磁与重力观测方法不同的物理基础和地质基础,指出震磁效应对于研究震源前兆的特殊意义,文中还介绍了１９７６唐山地震观测到震源前兆的部分实际地磁资料。     

The Epi－continental arc of Southeast China and relevant earthquakes

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Blind prediction of the site effects at Ashigara Valley,Japan, and its comparison with reality

Weak and strong ground motions were numerically predicted for three stations of the Ashigara Valley test site. The prediction was based on the records from a rock-outcrop station, one weak-motion record from a surface-sediments station, and the standard geotechnical model. The data were provided by the Japanese Working Group on the Effects of Surface Geology as a part of an international experiment. The finite-difference method for SH waves in a 2-D linear viscoelastic medium (a causalQ model) was employed.Comparison with the real records shows that at two stations the predictions fit better than at the third one. Strangely, the two better predictions were for stations situated at larger distances from the reference rock station (one station was on the surface, the other in a borehole). The strong ground motion (the peak acceleration of about 200 cm s^–2) was not predicted qualitatively worse than the weak motion (8 cm s^–2). A less sophisticated second prediction (not submitted during the experiment), in which we did not attempt to fit the available weak-motion record at the sedimentary station, agrees with the reality significantly better.     

Automatic equipment to monitor groundwater radon

Prototype instrumentation, able to automatically measure groundwater radon content variations, is presented. The equipment is made of stainless steel and has spherical valves with automatic and pneumatic control. The deemanation of the gases from the water is obtained by evacuating a suitable expansion chamber. The instrumentation can make discrete sampling ranging from 1 per hour to 1 per 99 hours. The equipment was tested in the laboratory: the efficiency was measured by means of a²⁶⁶Ra solution. A mean value of (0.65±0.07) count/s/Bq was obtained. A calibration test was carried out by comparing countings from the automatic equipment with those obtained by the standard laboratory cell. Results of an operational check over a period of approximately one year indicate that variations in radon at the calibration site are attributable more to meteorological than to tectonic causes.     

1983年菏泽5.9级地震前后沂水泉氡的变化

沂水泉位于山东省沂水一汤头断裂带上。多年来的观测分析表明,影响沂水泉氡值变化的最大干扰是降雨。由于这种干扰存在着“记忆”滞后影响,所以用一般的相关分析难以将这种影响排除干净。本文对最小二乘法为建立模型的判据,用动态灰箱分析法拟合并推估观测系统的变化。在分析中用了四个状态变量：长趋势成分Ｌ（ｔ）、年周期变化成分Ｐ（ｔ）、降雨影响部分Ｒ（ｔ）和随机变化部分Ｓ（ｔ）。经过分析表明,沂水泉氡的长趋势部分１