A Modified Capacity Spectrum Method with Direct Calculation of Seismic Intensity of Points on Capacity Curve

A direct methodology for solving the seismic intensity of each point on the capacity curve is proposed. By utilizing the procedure, a continuous curve between the structural response and the seismic intensity, the structural response function, can be easily generated. Unlike previous procedures that search for the performance point of a determined seismic intensity, the proposed methodology easily draws the full curve without iterations. The procedure is applicable to both a smooth design spectrum and an actual response spectrum. Examples indicate the methodology is accurate and fast, and convenient to be combined with existing procedures, such as Modal Pushover Analysis.     

Scalar Structure-Specific Ground Motion Intensity Measures for Assessing the Seismic Performance of Structures: A Review

The assessment of the seismic performance depends on the choice of the earthquake Intensity Measure (IM). During the past years many IMs, which take into account not only earthquake characteristics but also structural information, have been proposed. However, no consensus on which IM is the best predictor of the seismic response exists. Along these lines, the objective of this paper is to present the various developed scalar structure-specific seismic IMs and the problems associated with their use in practice, so that the engineer may become familiar with them and their implications in the context of Performance-Based Earthquake Engineering.     

Comparison of the Spectral Representation Method to Simulate Spatially Variable Ground Motions

The spectral representation method (SRM) is widely used when simulating spatially variable ground motions. It has mainly two formulas, i.e., the random amplitudes and the random phases formulas. There exist three methods for decomposing the cross spectral density matrix: Cholesky decomposition, eigen decomposition, and root decomposition. Therefore, there are six forms with respect to the different combinations of the simulation formulas and the decomposition methods. To provide researchers and engineers with the guidance on choosing simulation method, the six forms are systematically investigated from five aspects: the power intensity, response spectra, and stochastic error of auto/cross spectral density, Fourier spectra, and difference indexes for Fourier amplitudes and phases. Finally, we give the following advice: the characteristics of the ground motions simulated by the random amplitudes formula are independent of the decomposition method, while the characteristics of the ground motions simulated by random phases formula are dependent of the decomposition method. Furthermore, the root decomposition is strongly recommended when utilizing the random phases formula.     

Optimal Spectral Acceleration-based Intensity Measure for Seismic Collapse Assessment of P-Delta Vulnerable Frame Structures

This study proposes an “optimal” spectral acceleration-based intensity measure (IM) to assess the collapse capacity of highly inelastic frame structures vulnerable to the P-delta effect. The IM is derived from the geometric mean of the spectral pseudo-acceleration over a certain period interval. The lower bound period of the averaging interval is related to the mode in which 95% of the effective modal mass is exceeded. The upper bound period is 1.6 times the fundamental period. This IM provides minimum, or close to the minimum, dispersion for frames with different fundamental periods of vibration, or number of stories.     

Development of Damage Patterns and Fragility Curves in Brick-nogging Buildings from the Thabeikkyin Earthquake,Myanmar, 2012

The Thabeikkyin earthquake (moment magnitude scale of 6.8) occurred on November 11, 2012; its epicenter was located 25 km from Thabeikkyin Township, Mandalay Region, Myanmar. Many buildings were damaged severely during the earthquake. In this study, damage patterns of brick-nogging buildings were firstly developed, and damage grades were characterized to allow for easy classification of the damaged buildings. The damaged data of all building types in the surveyed areas were collected by classifying the four damage levels as no damage, slight damage, moderate damage, and heavy damage. To develop the damage patterns of brick-nogging buildings, damage categories were arranged into three damage grades (slight, moderate, and heavy damage). Secondly, a questionnaire survey was conducted to calculate the seismic intensities of the affected areas. Medvedev–Sponheuer–Karnik (MSK) seismic intensities for the surveyed areas were estimated by analyzing the questionnaire survey responses. Finally, fragility curves for brick-nogging buildings were constructed using the estimated seismic intensities from the survey responses combined with the damage levels. These fragility curves may be useful to assess damage to brick-nogging buildings and to predict the number of damaged buildings in future earthquakes.     

Use of Limit State Loss versus Intensity Models for Simplified Estimation of Expected Annual Loss

The expected annual monetary loss (EAL) is a powerful seismic performance indicator for a building as it quantifies repair and replacement costs considering a wide range of possible earthquake scenarios. Existing methods for the estimation of EAL are admirably rigorous but also represent a significant departure from current code assessment methods. By introducing simple loss vs. intensity relationships that are anchored to engineering limit states (set considering both structural and non-structural elements) it is shown that one can predict EAL values quickly, through a closed form expression that could be implemented easily in practice. The validity of the approach is demonstrated by comparing predictions of EAL with those obtained using refined EAL assessments, for a number of case study buildings. The limitations with the accuracy of the approach are discussed and the possibility of developing empirical loss vs. intensity relationships as part of future research is proposed.     

Relationships between Modified Mercalli Intensity and Engineering Ground-Motion of the Earthquakes in Persia

New empirical relationships between modified Mercalli intensity (MMI) and engineering ground acceleration (PGA) of the earthquakes were generated for the Iranian territory. MMI and PGA values were gathered from 16 large earthquakes. We derived two sets of relationships which predict MMI in terms of PGA; each developed using both horizontal and three components of accelerograms. The first set is independent of earthquake magnitude and epicentral distance. Better results were observed when magnitude and epicentral distance conditions were included into equations. They might be used for both rapid assessments of ground shaking and also mapping damage potential in Iran and neighboring area.     

基于区域联系和IPA的节事游客地方认同空间特征——以2011西安世界园艺博览会为例

本研究选取地方理论的地方认同维度,将其与节事研究领域相结合,以西安世界园艺博览会为案例,运用区域综合联系强度、IPA以及Taylor的距离衰减模型,探究参与该节事的游客对举办地西安的地方认同的空间特征。研究发现:世园会游客的地方认同在总体上表现为等级递减和跳跃式增长两种空间特征,且仅在国内各省(市、区)这个较大尺度上体现出明显的距离衰减效应。文章最后通过讨论提出了值得进一步研究的节事游客地方认同空间特征与空间极化、介入机会及空间扩散的关系问题。     

小区域旅游可持续发展战略初探——以荣城市为例

旅游可持续发展战略要求旅游业的发展与资源、环境相协调,旅游与自然、文化和人类生存环境成为一体。本文从旅游资源的分析入手,阐述了荣成市旅游可持续发展战略的指导思想和目标、旅游市场与旅游项目的开发;以荣城市为例提出了小区域旅游可持续发展的措施。     

测量脆弱漆膜强度的夹具的研制及其在漆器修复中的应用

为了评价漆器修复过程中的回软程度,自行研制了一种能够表征面积微小、形态不规则的脆弱漆膜强度的夹具。该夹具与万能材料试验机配合使用,可对漆膜回软前后的强度进行定量测试。实验结果表明,陕西兴平墓葬出土的一明代漆棺残片,经聚乙二醇水溶液回软处理后,膜强度得到了明显提高,回软修复效果良好,该工作对亚浸水类型漆器文物的回软修复、保护具有科学指导意义。