Advances in Microgeophysics for Engineering and Cultural Heritage

A large number of unconventional investigations have been implemented, tested, and validated in the field of microgeophysics, with the aim being to solve specific diagnostic and/or monitoring problems regarding civli engineering and cultural beritage studies. The investigations were carried out using different tomographic 2D and 3D approaches as well as different energy sources, namely sonic, ultrasonic and electromagnetic (radar) waves, electric potential fields, and infrared thermography. Many efforts have been made to modify instruments and procedures in order to improve the resolution of the surveys as well as to greatly reduce the time of the measurements without any loss of information. The main new methodologies here discussed arc the sonic imprint, the global tomographic traveltime, the electrical resistivity tomography, and the control of external films (patinas) grown on stone monuments. The results seem to be very promising and suggest that it is the moment to dedicate time and effort to this new branch of geophysics, so that these methodologies can be used even more to diagnose, monitor, and safeguard not only engineering buildings and large structures but also ancient monuments and cultural artifacts, like pottery, statues, etc..     

Near infrared observations of some of the IRC sources

Using an Infrared photometer with InSb photovoltaic detector at the 182cm Copernicus telescope of the Asiago Observatory, Italy, we have measured theJHKL’ M magnitudes of 12 IRC sources 7 of which are very late type stars with [I_CIT -K] greater than 5 magnitudes. These data have been fitted to blackbody distributions to obtain their effective temperatures. The present data, in combination with other available photometric data at longer wavelengths seems to indicate excess emission at 11 μm from sources 10066, 10510 and 10234, and at 19.8 μm from source 20052. The source 60098 shows extreme infrared colours. Work carried out when the first author was a guest scientist at Max Planck-Institut für Extraterrestrische Physik,Garching FRG.     

地震宽带波阻抗剖面及应用

宽带约束反演是用井中测得的波阻抗作为初始模型和约束条件，应用随机反演理论，与最优化计算技术相结合进行空间外推，从而获得最佳宽带波阻抗剖面。本文展示了实际应用的例子，证明了宽带约束反演是一种精度高、稳定性强、收敛快的反演方法，具有广阔的应用前景。     

地质雷达方法在水坝渗漏检测中的应用

水坝渗漏的成因较为复杂 ,通过物探方法检测可为分析研究坝体渗漏的原因以及采取相应的加固措施提供依据。渗漏部位因介质含水量的变化产生电性异常 ,为地质雷达方法的应用提供了有利条件。渗漏现象使雷达波幅频特性发生变化 ,对雷达图像的分析可以确定渗漏的部位和埋深。实践证明 ,地质雷达方法在水坝渗漏检测中有较好的应用效果     

工程力学研究所地震工程宽带网的建设

计算机技术和网络技术的发展及应用对加快地震工程领域的研究重要意义，我们建立内部网站，发布内部信息。通过网络服务器以宽带接入方式访问Internet，快速查询国际上有关地震工程、工程振动、防震减灾等方面的科研信息，及时公布和交流最新科研成果，为促进地震工程事业的发展提高了工作效率，简化了工作环节。     

博鳌地区沙坝-泻湖沉积及探地雷达的应用

通过钻孔资料和探地雷达（GPR）反射剖面，揭示了海南岛东部博螯地区晚更新世以来沙坝-泻湖体系沉积序列和内部反射结构，探地雷达（GPR）给出了有关沙体厚度，岩性特征，潜水面深度，海水侵入范围以及沙体含水性等重要参数，是海岸带环境调查的有效手段。通过和钻孔资料的对比，在玉带滩海岸沙坝上部层序中识别出两套具有区域意义的反射波组，南岗村沙洲浅滩识别出一套反射波组，综合分析表明，博螯地区沙坝-泻湖体系晚更新世以来随海平面的上升经历了基岩侵蚀→河流，河漫滩相→泻湖→海岸沙坝，半封闭泻湖，河口湾的演化过程。     

NIED seismic moment tensor catalogue for regional earthquakes around Japan: quality test and application

We have examined the quality of the National Research Institute for Earth Science and Disaster Prevention (NIED) seismic moment tensor (MT) catalogue obtained using a regional broadband seismic network (FREESIA). First, we examined using synthetic waveforms the robustness of the solutions with regard to data noise as well as to errors in the velocity structure and focal location. Then, to estimate the reliability, robustness and validity of the catalogue, we compared it with the Harvard centroid moment tensor (CMT) catalogue as well as the Japan Meteorological Agency (JMA) focal mechanism catalogue. We found out that the NIED catalogue is consistent with Harvard and JMA catalogues within the uncertainty of 0.1 in moment magnitude, 10 km in depth, and 15° in direction of the stress axes. The NIED MT catalogue succeeded in reducing to 3.5 the lower limit of moment magnitude above which the moment tensor could be reliably estimated. Finally, we estimated the stress tensors in several different regions by using the NIED MT catalogue. This enables us to elucidate the stress/deformation field in and around the Japanese islands to understand the mode of deformation and applied stress. Moreover, we identified a region of abnormal stress in a swarm area from stress tensor estimates.     

地质雷达方法在城市地下建(构)筑物权属调查中的应用

城市地下空间建筑包括地铁，地下车库，人防工程及其它类型的地下掩埋体，运用地质雷达的方法可以解决其权属边界问题。这是一个值得我们关注的物探发展领域。     

三维介质中探地雷达(GPR)波传播逐段迭代射线追踪方法研究和应用

基于F erm at原理和Sne ll定理对三维任意界面情况下的两点间GPR波传播射线追踪问题进行了研究,采用了一个适用于任意界面情况下计算反(折)射点的一阶近似公式,从任意给定的初始路径出发进行逐段迭代计算,给出了三维逐段迭代射线追踪算法的计算格式,并进行了三维介质下射线追踪计算。结果表明计算速度相当快,且其计算精度可以根据需要达到任意要求。在此基础上,根据雷达波传播规律,考虑每一段的能量损失。根据地质雷达的发射子波,最终获得三维介质中雷达波传播和接收记录。并将结果应用于实际剖面拟合中,提高了解释的精度。