EFFECT OF SLAB FLEXIBILITY ON INTERACTION BETWEEN TWO CIRCULAR FOUNDATIONS

The paper is aimed at investigating the effect of foundation rigidity on dynamic stiffness for two circular foundations on a viscoelastic medium. To generate the dynamic stiffness, a substructure technique is employed. For the substructure of a viscoelastic medium, the solution for wave motion reported in Reference 11 is used. For the substructures of two flexible foundations, classical plate theory with the inertial force neglected is employed to find the displacement fields of the foundation plates subjected to the interaction stresses. Then, the continuity condition for all the substructures is imposed implicitly by using the variational principle; then with the help of the reciprocal theorem the dynamic stiffness for the two flexible foundations can be obtained. For the numerical study, the boundary condition at the rims of both foundation plates is assumed to be a hinge connection to superstructures. Some numerical investigations are performed and the effect of foundation rigidity on dynamic stiffness is examined. Some discussions and conclusions are also made.     

PARAMETER AND VARIANCE ESTIMATION IN GEOTECHNICAL BACKANALYSIS USING PRIOR INFORMATION

A probabilistic framework to perform inverse analysis of geotechnical problems is presented. The formulation allows the incorporation of existing prior information on the parameters in a consistent way. The method is based on the maximum likelihood approach that allows a straightforward introduction of the error structure of field measurements and prior information. The difficulty of ascribing definite values to the uncertainties associated with the various types of observations is overcome by including the corresponding variances in the set of parameters to be identified. The inverse analysis results in a minimization problem that is solved by coupling the optimization technique to the finite element method. Two examples are presented to illustrate the performance of the method. The first one corresponds to a synthetic case simulating the excavation of a tunnel. Young's modulus, K₀ value and measurements variances are identified. The second case concerns the excavation of a large underground cavern in which again Young's modulus and K₀ are identified. It is shown that introduction of prior information permits the estimation of parameters more consistent with all available informations that include not only monitored displacements but also results from in situ tests carried out during the site investigation stage.     

GPS技术和遥感影像在编制重点文物地图中的应用——以制作武汉大学校园重点文物图为例

GPS技术具有实时导航、定位准确的特点,遥感影像能提供快速及时的地理信息,它们当前还未广泛应用于地图的制作,本文尝试将这两种技术结合应用来编制地图,进而探讨在制作过程中的数据处理、重点文物图的设计与编制等问题;并以制作武汉大学的重点文物图为例,来说明和分析这种制作方法所具有的显著特点和具体操作的可行性。     

地震雷达

利用绿色、环保的人工震源,主动向地下发射地震波,构建地震雷达,实现大范围的地下探测,是地球科学的一个前沿课题.最早,探测地球内部利用的是天然地震产生的地震波,这是因为天然地震释放的能量大,一次天然地震释放的能量相当于万吨级炸药.几千公里远处仍可以接收到信噪比大于1的地震波信号,但天然地震发生频度低和震源位置定位精度低限制了利用天然地震进行地下探测的精度;后来,利用人工源的地震勘探得到迅速的发展,探测精度明显提高,但受到人工源能量的限制,探测的空间尺度有限;今天,以小当量激发实现大尺度探测是发展地震雷达的一个关键问题,是将地震波理论和现代信息科学相结合的一个新的领域.发展人工震源的编码和接收信号的解码等理论和技术,可以从电磁波雷达在过去半个世纪所经过的道路得到许多借鉴和启发.可以预期,地震雷达的发展将会对观测地震学带来全面的影响.     

河南省科研院所科技产业化融资问题研究

科技产业化是科研院所科技资源转化为经济效益、科研成果转化为现实生产力最直接的方式,而有效的融资是科技产业化的必备条件。河南省的科研院所是河南省科技创新的重要源泉。文章在提出该省科研院所科技产业化必要性的基础上,分析了科技产业化融资存在的问题、科研院所科技产业化所需的融资环境,并提出了解决融资问题的对策措施。     

VPN技术在防震减灾中的应用

简要介绍VPN技术的应用、原理与搭建,并介绍了两个应用实例。显示了VPN技术在防震减灾工作中有广阔的应用前景。     

安装CB3磁变仪磁系的技巧

安装磁系过程中从竹片上取下吊丝和磁系放入仪器盒时很容易弄断吊丝。若在取下吊丝时在吊丝头的边上滴少许酒精,就很容易取下吊丝了。在磁系放入仪器盒时,若用头发丝或细线粘在纸片上,将纸片放入仪器盒内,轻轻拉紧纸片,磁系靠在纸片上慢慢滑入仪器盒,就不容易弄断吊丝。     

TSP203在雪峰山隧道施工地质超前预报中的应用研究

介绍了地质超前预报的研究进展和TSP203的工作原理、数据处理、解译技术及其在雪峰山隧道施工地质超前预报中的应用.通过对比分析验证了预报结果的准确性,展示了TSP203探测系统在隧道施工地质超前预报中的广阔前景.     

高压水射流与潜水员水下作业安全研究

从高压水射流技术在水下工程中应用及高压水射流的作用效应和伤害特征着手,分析影响水下高压水射流作业安全的因素,总结各国制订高压水射流作业的安全标准规程现状,提出制订我国水下高压水射流作业安全规程若干认识和设想。     

应用荧光抗体技术检测牙鲆体内的河流弧菌

用灭活的河流弧菌(Vibrio fluvialis)抗原,注射免疫实验兔,制得凝集价为1∶5 120的抗血清。用试管凝集法检测了抗血清的特异性,再用免疫吸附法去除交叉反应,从而得到高效价、高特异性的抗河流弧菌血清。用所制备的抗血清在实验室中建立起河流弧菌荧光抗体检测技术(FAT),在荧光显微镜下可清楚地看到被标记的病原菌,整个检测过程只需3h。用河流弧菌感染牙鲆(Paralichthys olivaceus),24 h后,用FAT测定牙鲆的血液、肾脏和肝脏中的河流弧菌,在血液中河流弧菌的检出率最高,其次是肾脏,肝脏的检出率最低。以上结果表明:荧光抗体技术可以快速、灵敏、准确地检测出牙鲆体内的河流弧菌。