Response spectra for the deep sediment-filled Rhône Valley in the Swiss Alps

We present numerical modeling of earthquake ground motion for various profiles across the Swiss Rhône Valley and characterize the seismic response in terms of spectral acceleration. First, we evaluate the relative amplification of 2D with respect to 1D response. Then, we show how the selected bedrock spectrum influences the response spectra of the valley sites. Particular attention is paid to how the internal sediment structure and the often weakly constrained Q-factor shape the seismic response. Results obtained for the different profiles are compared with reference spectra (Swiss building code and Eurocode 8) and for one profile with recorded data as well. From this comparison, we infer that the surficial layer strongly influences spectral acceleration values between 0.1 and 1 s. The total thickness of sediments significantly affects the seismic response at longer periods around the fundamental period of the studied valley sections between 1.8 and 3.6 s.     

地震监测仪器综合管理系统的设计与应用

随着地震监测建设力度的增加,地震监测系统主要涵盖了测震、形变、流体、磁电等四大学科的地震观测仪器.分析现有的仪器运维管理工作状况,存在着仪器组成复杂、配套设备繁杂、观测项目众多、维修更新管理落后等问题,结合江苏省地震观测仪器管理运维的实际情况,采用PHP语言开发了基于MySQL关系型数据库的地震监测仪器综合管理系统,初步实现了对地震监测仪器的运维监控和维修管理的网络化和实时化,该综合管理系统已在江苏省地震监测中心服务器上运行2年,取得较好的效果.     

GOCAD的三维可视化建模在铀矿勘查中的应用

文章突破以往常规采用的平面图、剖面图和轴测投影原理等二维平面表述方法,以相山铀矿田中的某产铀区块为实例,利用国际上先进的三维地质建模软件GOCAD,通过地形模型构建、地层模型构建、构造模型构建等步骤,实现了研究区地质数据的三维实体化展示,并针对所建三维模型在找矿靶区圈定、矿山开发设计等方面的应用开展了初步讨论。     

Practical evaluation of sinkage and trim effects on the drag of a common generic freely floating monohull ship

A practical method to account for the influence of sinkage and trim on the drag of a freely floating (free to sink and trim) common monohull ship at a Froude number F ≤ 0.45 is considered. The sinkage and the trim are estimated via two alternative simple methods, considered previously. The drag is also estimated in a simple way, based on the classical Froude decomposition into viscous and wave components. Specifically, well-known semiempirical expressions for the friction drag, the viscous pressure drag and the drag due to hull roughness are used, and the wave drag is evaluated via a practical linear potential flow method. This simple approach can be used for ship models as well as full-scale ships with smooth or rough hull surfaces, and is well suited for early ship design and optimization. The method considered here to determine the sinkage and the trim, and their influence on the drag, yields theoretical predictions of the drag of the Wigley, S60 and DTMB5415 hulls that are much closer to experimental measurements than the corresponding predictions for the hull surfaces of the ships in equilibrium position at rest. These numerical results suggest that sinkage and trim effects, significant at Froude numbers 0.25 < F, on the drag of a typical freely floating monohull ship can be realistically accounted for in a practical manner that only requires simple potential flow computations without iterative computations for a sequence of hull positions.     

Algorithm for generation of stratigraphic profiles using cone penetration test data

Cone Penetration Test (CPT) data are often used directly in the design of shallow and deep foundations and many other applications. To produce more cost-effective designs, it is advantageous to use CPT data to establish stratigraphic profiles as well. Algorithms to generate a stratigraphic profile using data from an individual CPT sounding and a Soil Behavior Type (SBT) chart as inputs are presented. Two SBT charts from the literature were selected and modified to eliminate ambiguity in soil classification. Novel algorithms were developed for handling the occurrence of thin layers within a stratigraphic profile to account for the fact that the standard CPT cone cannot accurately sense layers with thickness below a certain limit and a representative cone resistance cannot be obtained if the layer is too thin. Likewise, the algorithms prevent the creation of a soil profile with adjacent layers of essentially the same soil by consolidating layers appropriately. The algorithms presented generate a design soil profile, produced using a precise classification based on soil type and state and by elimination of artificial layering, that can be more effectively used in design.     

定位统计图表的几何定位与基础图表构建

归纳和总结了定位统计图表表达的理论,给出了定位统计图表的数学模型,并根据统计图表的坐标系维度对其进行了分类。通过统计图表的定位方式抽象出定位图元的几何类型,并相应给出了定位参数的计算方法。最后程序化地实现了直方图、柱状图、扇形图、饼状图、玫瑰图等基础图表的几何定位和自动构建,极大地提高了定位统计地图的设计水平和制作效率。     

Cumulative gain and lift charts for model performance assessment in mineral potential mapping

Model performance assessment is a key procedure for mineral potential mapping, but the corresponding research achievements are seldom reported in literature.Cumulative gain and lift charts are well known in the data mining community specialized in marketing and sales applications and widely used in customer churn prediction for model performance assessment.In this paper, they are introduced into the field of mineral potential mapping for model performance assessment.These two charts can be viewed as a graphic representation of the advantage of using a predictive model to choose mineral targets.A cumulative gain curve can represent how much a predictive model is superior to a random guess in mineral target prediction.A lift chart can express how much more likely the mineral targets predicted by a model are deposit-bearing ones than those by a random selection.As an illustration, the cumulative gain and lift charts are applied to measure the performance of weights of evidence, logistic regression, restricted Boltzmann machine, and multilayer perceptron in mineral potential mapping in the Altay district in northern Xinjiang in China.The results show that the cumulative gain and lift charts can visually reveal that the first three models perform well while the last one performs poorly.Thus, the cumulative gain and lift charts can serve as a graphic tool for model performance assessment in mineral potential mapping.     

Design energy input spectra for moderate-to-high seismicity regions based on Colombian earthquakes

Energy input spectra applicable to the seismic design of structures in moderate-to-high seismicity regions are proposed. Such design inputs are derived from the bilinear envelope of individual spectra obtained for 144 ground motions recorded in Colombia. In the short period region the spectra account for the increase of input energy, due to plastification of the structure, through a new formula derived from extensive nonlinear analyses. The proposed energy input design spectra are compared with the provisions of the Colombian seismic code, and with those proposed for Japan, Spain, Iran and Greece. It is found that the proposed spectra are more demanding than the current Colombian seismic code, and that they agree with those developed recently for six cities in Greece, yet applying a different approach. An empirical equation for estimating the portion of the total seismic input energy that contributes to structural damage is also developed.     

Selection of earthquake ground motion records: A state-of-the-art review from a structural engineering perspective

This paper reviews alternative selection procedures based on established methods for incorporating strong ground motion records within the framework of seismic design of structures. Given the fact that time history signals recorded at a given site constitute a random process which is practically impossible to reproduce, considerable effort has been expended in recent years on processing actual records so as to become ‘representative’ of future input histories to existing as well as planned construction in earthquake-prone regions. Moreover, considerable effort has been expended to ensure that dispersion in the structural response due to usage of different earthquake records is minimized. Along these lines, the aim of this paper is to present the most recent methods developed for selecting an ‘appropriate’ set of records that can be used for dynamic analysis of structural systems in the context of performance-based design. A comparative evaluation of the various alternatives available indicates that the current seismic code framework is rather simplified compared to what has actually been observed, thus highlighting both the uncertainties and challenges related to the selection of earthquake records.     

基于RouterOS技术的12322防震减灾电话呼叫系统双线路设计与实现

根据12322电话呼叫系统的实际工作情况,提出了系统线路备份方案,设计了适合新疆维吾尔自治区地震局现状的12322电话呼叫系统双线路,并给出整体思路、实际配置及调试过程,该方案将会提高12322电话呼叫系统线路的稳定运行,同时也提高了系统的安全运行效率。