基于性能的地震工程研究的新进展及对结构非线性分析的要求

结合国际地震工程界提出的新一代基于性能的地震工程的框架方法,重点阐述了性能评估中涉及的主要问题。对性能评估使用的静力非线性分析、动力非线性分析方法进行了总结,在此基础上详细阐述了在基于概率的性能评估中有应用前景的增量动力分析方法的概念、相关问题及其应用,并简要介绍了基于增量动力分析思想提出的一些简化方法。最后提出了今后研究的建议,特别是结构非线性分析方面的研究重点。     

基于轨迹偏移算法的居民就医时空特征与空间格局分析

居民就医时空特征与空间格局反映了医疗设施的服务能力与布局合理性.本文以厦门岛为例,采用出租车轨迹数据,探讨了居民就医的时空特征和空间格局.论文提出了基于道路中心线的研究单元划分方法;提出OD轨迹偏移算法,更精细地提取出三级医院的就医OD数据,改善传统的缓冲区分析法中精确度较低的问题;对居民就医行为进行时空特征分析;基于...     

Application of FY-2C Cloud Drift Winds in a Mesoscale Numerical Model

Statistical tests and error analysis of cloud drift winds(CDWs) from the FY-2C satellite were made by using radiosonde observations.According to the error characteristics of the CDW,a bias correction using the thermal wind theory was applied in the data quality control.The CDW data were then assimilated into the GRAPES-meso model via the GRAPES-3DVar.A torrential rain event that occurred in northwestern China during 1-2 July 2005 was simulated.The results indicate that the CDW data were mainly distribute...     

Satellite-tracked drifting buoy observations in the south equatorial current in the Indian Ocean

Three satellite-tracked drifting buoys released in the south equatorial current in the Indian Ocean followed the path of the current moving westward approximately zonally in the vicinity of 10 S latitude. On nearing the east coast of Africa two buoys moved north and the third moved south. Over the open sea regime the buoys moved with a speed of approximately 30 cm/s at an angle of about 35° to the left of the wind. The overall tendencies seen in the buoy drift are similar to those observed elsewhere in the world oceans.     

校正大地电磁测深中静态效应的首枝重合法

着重论述如何用首枝重合法校正静态效应。提出用等权正交多项式拟合视电阻率曲线真实位置；指出了选择参考频率的原则；以及如何自动识别是否有静态效应的影响，产生了何种形式的静位移。分析静校正处理后的资料可知，静态效应影响几乎无所不在，但在盆地沉积中心有可能无静位移情形；静位移的形式是多样的，但主体形式是ρ＿（ＴＥ）曲线向上，ρ＿（ＴＭ）曲线向下位移，且ρ＿（ＴＥ）曲线在ρ＿（ＴＭ）曲线之上；ρ＿（ＴＥ）曲线与ρ＿（ＴＭ）曲线基本上一样容易产生静位移。     

Reciprocity theorem to compute the static deformation due to a point dislocation buried in a spherically symmetric earth

Intriguing reciprocity relations exist between the static deformation excited by a point dislocation in a SNREI earth and those generated by external forces, such as tidal force, surface loading and surface shear forces. Coseismic deformations can be rewritten as follows: (1) potential change in terms of the tide deformation field, (2) radial displacement in terms of the load and tidal deformation fields, and (3) tangential displacement in terms of shear and torsional deformation fields. The relations greatly reduce the effort to compute the coseismic crustal deformation in a spherically symmetric earth.     

Static deformation of two welded half-spaces due to very long strike-slip dislocations

Closed form analytic expressions for displacement and stresses at any point of either of the two homogeneous, isotropic, perfectly elastic half-spaces in welded contact due to very long strike-slip dislocations are obtained. Both cases of vertical and horizontal strike-slip dislocations are discussed in detail. Variation of the displacement with horizontal distance from the fault and with vertical distance from the interface for a vertical strike-slip fault is studied numerically.     

Time-dependent behaviour of the rock mass

Summary The strength of intact rock and the rock mass is time-dependent. For intact rock experimental verification is available, for the rock mass the scale of time-dependence is a matter of judgement. Rock mass classifications do however emphasize the effect of time on tunnel stability. This paper examines the source of time-dependence in rocks and the rock mass and suggests a technique for estimating the long term strength. The long term strength of the rock mass is controlled by the time-dependent weakening of intact rock. Frictional resistance, a major source of rock mass strength, increases rather than decreases with time. Lifetime estimation for rocks can be accomplished phenomenologically or mechanistically. The first is a statistical process of wide applicability, the second is more restrictive in usage as its applies only to materials that suffer time-dependent strain (creep). Although the mechanistic route is more appealing, it has a major drawback as it concentrates on steady state creep. There is no strong evidence for steady state creep in rocks. The technique for long term prediction is developed through the analysis of the failure rate under constant load. The failure rate for a given load and environment is established from the frequency distribution of time-to-failure data as measured in static fatigue tests. As expected, the failure rate is strongly affected by both the loading and the environmental condition. The influence, however, is systematic and predictable.     

岩石在动载作用下的破坏与强度

研究岩石的动载性能,在凿岩爆破上有重要意义。分段式霍布金生杆已应用于研究岩石对波动载荷的效应。作者使用改型的霍布金生杆法对岩石试件在动载下的破坏强度作了试验研究。冲击试验台配合微处理机作高速数据显示与处理,借助应力波在弹性杆中的一维理论对数据进行解释。测定了多种岩石静载与动载的强度,并对岩石试件尺寸及加载速率的影响也作了试验。     

加油站的雷电防护设计

通过对加油站所处环境特点、系统特点中雷电灾害各因素的分析，对加油棚、油罐及附属建筑的直击雷防护和接地，加油站电源、信号系统的雷电系统防护和静电防护等，依据GB50057、IEC61312、GB50156—2002标准对雷电防护的要求，提出了系统的解决方案。