地震定位研究及应用综述

地震定位是地震学中最经典、最基本的问题之一，提高定位精度也一直是地震学应用研究的重要课题之一。本文就目前各种地震定位方法进行了大体分类并概述了基本原理及其应用，介绍了目前在国内各实时地震观测系统中应用的台网定位方法，同时将部分台网方法应用于黑龙江省绥棱爆破的定位。     

弦支穹顶结构的抗震性能研究

弦支穹顶是一种受力性能优良的结构体系，它综合了单层网壳结构和索穹顶结构的优点，详细分析了影响弦支穹顶结构自振特性的各类参数，指出了边界条件对结构抗震性能的决定性影响。研究表明：当采用径向滑动边界时，即边界节点竖向和法向受到约束而容许径向在水平面滑动时，局部布索的弦支穹顶具有较佳的抗震性能；当边界条件相同时，弦支穹顶在水平地震和竖向地震作用下反应相似，只是程度上不同。     

新型灌浆材料在已建砌体结构抗震加固中的应用

具有悠久历史的石结构是砌体结构的重要组成部分，本文作者经广泛调研和试验分析：(1)提出以石粉为集料对石砌体进行抗震加固，寓环保与防灾于一体；(2)给出新型浆体配比和复合砂浆的强度等级，阐述加固技术和方法，建立灌浆石砌体抗震抗剪强度公式；(3)阐明抗震验算方法，提出基于模糊随机可靠理论的可靠性分析方法。     

考虑土体固液二相性质的地下管线地震反应研究

本文将管线周围的土体视为固-液二相介质，采用考虑地震过程中土体内孔隙水压力的增长和消散的有效应力分析方法，并以非线性的土体本构模型模拟土体动力特性的改变以及在孔隙水压作用下的变形，以求接近土体的真实地震反应。研究表明随着土体软化程度的不同，受到土体约束的管线应力亦发生相应变化。文中详细研究了地震动峰值、管线直径、行波波速和入射角度等对管线应力的影响。     

不同型式暗支撑短肢剪力墙抗震性能试验研究

本文选取短肢剪力墙结构体系中较为薄弱的抗震构件“一”形短肢剪力墙，采用不同的暗支撑型式进行了两个1／2缩尺的带暗支撑短肢剪力墙构件的低周反复荷载试验，比较分析了它们的承载力、刚度、延性、滞回特性、耗能能力及破坏机制，建立了其承载力计算模型与方法。计算结果与实测值符合较好。     

探讨渤海及周边地区海洋平台抗震设防水准

介绍了美国API规范的内容，并将南加利福尼亚和中国渤海海域地震活动特征与地震危险性进行对比. 对比结果表明，无论在地震活动的频度与强度还是地震危险性分析结果上，渤海都比南加州弱. API规范指出，对于南加利福尼亚地区的永久性建筑， 强度设计水准取重现期200 a，变形设计水准取几百至几千年. 我国相关规范规定的海洋平台强度设计和变形设计水准分别取500 a和10 000 a，过于保守. 同时，与其它建构筑物的抗震水平相比较，甲类建筑变形设计水准取设计基准期100 a内超越概率2%~3%，乙、丙类取50 a内2%~3%，考虑海洋平台易于引起严重的次生灾害，变形设计水准取设计基准期30 a内1%（相当于重现期3 000 a）应是安全的. 基于上述对比分析， 同时考虑到经济承受能力以及与现行标准的连贯性， 建议我国海洋石油平台的强度设计水准和变形设计水准分别取200 a和3 000 a.      

A crustal seismic velocity model for the UK, Ireland and surrounding seas

A regional model of the 3-D variation in seismic P -wave velocity structure in the crust of NW Europe has been compiled from wide-angle reflection/refraction profiles. Along each 2-D profile a velocity–depth function has been digitised at 5 km intervals. These 1-D velocity functions were mapped into three dimensions using ordinary kriging with weights determined to minimise the difference between digitised and interpolated values. An analysis of variograms of the digitised data suggested a radial isotropic weighting scheme was most appropriate. Horizontal dimensions of the model cells are optimised at 40 × 40 km and the vertical dimension at 1 km. The resulting model provides a higher resolution image of the 3-D variation in seismic velocity structure of the UK, Ireland and surrounding areas than existing models. The construction of the model through kriging allows the uncertainty in the velocity structure to be assessed. This uncertainty indicates the high density of data required to confidently interpolate the crustal velocity structure, and shows that for this region the velocity is poorly constrained for large areas away from the input data.     

High-resolution structures of the Landers fault zone inferred from aftershock waveform data

High-frequency body waves recorded by a temporary seismic array across the surface rupture trace of the 1992 Landers, California, earthquake were used to determine fault-zone structures down to the seismogenic depth. We first developed a technique to use generalized ray theory to compute synthetic seismograms for arbitrarily oriented tabular low-velocity fault-zone models. We then generated synthetic waveform record sections of a linear array across a vertical fault zone. They show that both arrival times and waveforms of P and S waves vary systematically across the fault due to transmissions and reflections from boundaries of the low-velocity fault zone. The waveform characteristics and arrival-time patterns in the record sections allow us to locate the boundaries of the fault zone and to determine its P - and S -wave velocities independently as well as its depth extent. Therefore, the trade-off between the fault-zone width and velocities can be avoided. Applying the method to the Landers waveform data reveals a low-velocity zone with a width of 270–360 m and a 35–60 per cent reduction in P and S velocities relative to the host rock. The analysis suggests that the low-velocity zone extends to a depth of ∼7 km. The western boundary of the low-velocity zone coincides with the observed main surface rupture trace.     

Urban Seismic Risk Evaluation: A Holistic Approach

Risk has been defined, for management purposes, as the potential economic, social and environmental consequences of hazardous events that may occur in a specified period of time. However, in the past, the concept of risk has been defined in a fragmentary way in many cases, according to each scientific discipline involved in its appraisal. From the perspective of this article, risk requires a multidisciplinary evaluation that takes into account not only the expected physical damage, the number and type of casualties or economic losses, but also the conditions related to social fragility and lack of resilience conditions, which favour the second order effects (indirect effects) when a hazard event strikes an urban centre. The proposed general method of urban risk evaluation is multi hazard and holistic, that is, an integrated and comprehensive approach to guide decision-making. The evaluation of the potential physical damage (hard approach) as the result of the convolution of hazard and physical vulnerability of buildings and infrastructure is the first step of this method. Subsequently, a set of social context conditions that aggravate the physical effects are also considered (soft approach). In the method here proposed, the holistic risk evaluation is based on urban risk indicators. According to this procedure, a physical risk index is obtained, for each unit of analysis, from existing loss scenarios, whereas the total risk index is obtained by factoring the former index by an impact factor or aggravating coefficient, based on variables associated with the socio-economic conditions of each unit of analysis. Finally, the proposed method is applied in its single hazard form to the holistic seismic risk evaluation for the cities of Bogota (Colombia) and Barcelona (Spain).