Seismic Hazard Analysis Using Discrete Faults in Northwestern Pakistan: Part I – Methodology and Evaluation

This article is the first of two companion articles that evaluate the seismic hazard in northwestern Pakistan. The area, located at the western edge of the Himalayas, has numerous active faults including the Main Boundary Thrust (MBT) and Main Mantle Thrust (MMT). This article describes the methodology used to perform regional deterministic and probabilistic seismic hazard analyses. Here, seismic sources were defined from 32 identified faults while prior studies have been based on diffuse seismicity and areal source zones. Fault parameters were selected using available data and empirical correlations for faults elsewhere. Recurrence relations were constructed for all discrete faults based on both historical and instrumented seismicity in addition to geologic evidence. Due to lack of region specific attenuation relationships, four plate boundary attenuation relations from the Next Generation Attenuation of Ground Motions Project [Abrahamson et al., 2008 Abrahamson, N., Atkinson, G., Boore, D., Bozorgnia, Y., Campbell, K., Chiou, B., Idriss, I. M., Silva, W. and Youngs, R. 2008. Comparisons of the NGA ground-motion relations. Earthquake Spectra, 24(1): 45–66. [Crossref], [Web of Science ®] , [Google Scholar]] were employed to predict ground motions. Predicted ground motion parameters are compared to measurements from the recent 2005 Kashmir earthquake. In the companion article, the methodology developed and evaluated here is used to conduct deterministic and probabilistic seismic hazard analyses for the entire study region.     

Multi-Component Seismic Response Analysis – A Critical Review

Issues related to multi-components seismic response analysis are critically reviewed and their implications with respect to the current codified approaches are studied. The issues specifically addressed are: (1) the directions of earthquake forces to excite a structure when the direction of the potential epicenter is known; (2) different commonly used combination rules to obtain the critical response when responses are available in different directions; and (3) the applicability of the combination rules for elastic and inelastic analyses. Based on an extensive parametric study consisting of three-dimensional 1-, 3-, 8-, and 15- story buildings made of moment-resisting steel frames and 20 recorded earthquakes, it is observed that the principal components produce larger responses than the normal components. The 30% and SSRS rules generally underestimate the axial loads in columns. The 30% combination rule is slightly better than the SSRS rule. For both rules, the uncertainty in the estimation of the axial loads in terms of COV is very large (about 25%). The statistics obtained for axial loads and total base shear indicate that the combination rules are applicable for both elastic and inelastic cases. The critical response could be obtained for an orientation different from that of the principal components. The differences are found to be slightly greater for the scaled earthquakes producing a considerable inelastic behavior. Considering the enormous amount of efforts needed to address the directionality effect, it is believed that the responses obtained by the principal components will be acceptable in most cases; however, for critical structures the components should be rotated to obtain the critical responses.     

Seismic Performance Assessment of Steel Frames with Shape Memory Alloy Connections. Part I — Analysis and Seismic Demands

This article is the first of two companion articles that evaluate the seismic performance of steel moment-resisting frames with innovative beam-to-column connections that incorporate shape memory alloys (SMAs) to dissipate energy and provide recentering effectively during large earthquakes. Two types of SMA elements are considered: (1) superelastic SMA elements with recentering capability and (2) martensitic SMA elements with high energy dissipation capacity. This article describes the fundamental engineering characteristics of these SMA connections, their modeling in connections for nonlinear dynamic finite element analysis of building frames, and the validation of these connection models using data from full-scale experimental tests that were performed in previous research at Georgia Institute of Technology. Using three- and nine-story partially restrained (PR) moment frames selected as case studies from the SAC Phase II Project, nonlinear time history analyses of frames with and without SMA connections were conducted using suites of ground acceleration records. The beneficial effects of SMA connections on peak and residual deformation demands are quantified and discussed.     

Seismic Performance Assessment of Steel Frames with Shape Memory Alloy Connections,Part II – Probabilistic Seismic Demand Assessment

This article is the second of two companion articles that evaluate the seismic performance of steel moment-resisting frames with innovative beam-to-column connections that incorporate shape memory alloy (SMA) elements to enhance the energy dissipation characteristics of such frames. Building upon the finite element models of the three- and nine-story frames that were developed in the first article, the seismic demands on partially restrained frames with and without SMA elements are evaluated within a probabilistic framework. The results of this evaluation, expressed in the form of demand hazard curves, depict the effectiveness of the SMA connections in enhancing building performance over a range of demand levels. Martensitic SMA connections are most effective in controlling deformation demands on the frame from high levels of seismic intensity. In contrast, the recentering capability of superelastic SMA connections make them most suitable for reducing residual deformations in the structure, a reduction that is achieved at the expense of increased deformation demands during strong excitation. However, neither connection is uniformly beneficial at all hazard levels, suggesting that SMA systems must be tailored to the specific performance objectives for the building structural system.     

Theoretical and Numerical Seismic Analysis of Masonry Building Aggregates: Case Studies in San Pio Delle Camere (L’Aquila,Italy)

Masonry building aggregates are large parts of the Italian building heritage often designed without respecting seismic criteria. The current seismic Italian code does not foresee a clear calculation method to predict their static nonlinear behavior. For this reason, in this article a simple methodology to forecast the masonry aggregate seismic response has been set up. The implemented procedure has been calibrated on the results of two FEM structural analysis programs used to investigate three masonry building compounds. As a result, a design chart used to correctly predict the base shear of aggregate masonry units starting from code provisions has been set up.     

The Use of a Large-Scale Seismic Vulnerability Assessment Approach for Masonry Façade Walls as an Effective Tool for Evaluating,Managing and Mitigating Seismic Risk in Historical Centers

ABSTRACT

The vulnerability assessment of the building stock in a given territorial area, such as a city or an entire country, is a key prerequisite for evaluating risk, not only because of the potential physical consequences resulting from the occurrence of an event, but also because it is one of the few aspects in which engineering research can intervene. In fact, the rigorous vulnerability assessment of existing buildings followed by the implementation of appropriate retrofitting solutions can help to substantially reduce the levels of physical damage and economic impact of future events. Particularly regarding the seismic vulnerability assessment of historical centers, the amount of knowledge that has been accumulated over the past decades, together with the broad damage data obtained from post-earthquake damage surveys, provides a singular opportunity to develop and calibrate innovative large-scale seismic vulnerability assessment approaches, which can be used to outline and support risk mitigation and management strategies. This article addresses this issue by discussing the use of a large-scale seismic vulnerability assessment methodology for masonry façade walls as a tool for evaluating the potential benefit resulting from the application of different seismic retrofitting strategies, both considering their contribution to reduce post-event urban losses and accessibility.     

Seismic History of the Church of San Pietro Di Coppito in L’Aquila

After the terrible 18th-century earthquakes—in L’Aquila in 1703, Lisbon in 1755, and Reggio Calabria in 1783—specific anti-seismic precepts were introduced in the rules of the art of masonry construction. Scrupulously adhered to in the first years after the earthquake, those precepts gradually ceased to be used until they were almost completely forgotten, centuries later, by which time the earthquake had become a distant memory. The church of San Pietro di Coppito, one of the most important churches of L’Aquila, is emblematic of this singular process. Deeply transformed in accordance with new anti-seismic construction techniques after it was particularly badly damaged in the terrible 1703 earthquake, the church was subjected, in the 1970s, to drastic alterations by the Commissioner Mario Moretti, who demolished all the baroque additions and redesigned it in the “medieval Abruzzo” style, eliminating in the process the intelligent anti-seismic provisions introduced in the 18th century. In addition to documentary purposes, this work aims to underline the effectiveness of this early 18th-century example of anti-seismic engineering in the belief that the constructive solutions it employed could still form a valid architectural and structural model in view of the massive restoration task for which, unfortunately, L’Aquila is still waiting today.     

Assessing Seismic Social Vulnerability in Urban Centers — the Case-Study of Nablus,Palestine

ABSTRACT

Seismic risk depends on three factors: seismic hazard, exposure of assets and communities, and vulnerability—physical and social. Whereas hazard and exposure are harder to act upon, vulnerability can be significantly reduced, if properly characterized for each asset, population, or society in general. This article assesses the social vulnerability and resilience level of the city of Nablus, an important urban center in Palestine. The region, considerably exposed to seismic hazard, features, from the in-built view point, very recent or very old historical buildings, without seismic design provisions. On the socio-economic side, the well-known political conflicts and societal challenges are key vulnerability factors. The method employed was based on Social Vulnerability Indicators (SoVI) extracted from census data, integrated with the more recent SCORECARD approach, which was applied to the urban community of Nablus. The goal was both to obtain an overall vulnerability score for the city and to characterize internal differences among its main areas, connected to its historical urban expansion and patterns. The results show that both physical and social vulnerability can be related and that the city development patterns can mirror the relative social vulnerability.     

Supply-Side Urbanization? A Pooled Time Series Analysis

Tests of Tolley's supply-driven urban growth model for expanding sets of countries for time periods varying from 1831–1980 to 1951–1980 lead to its rejection in most contexts. The exception is for higher-income market economies, where supply-driven and demand-driven determinants of urban growth are shown to alternate with long-wave periodicity: During epochs of structural transformation following stagflation crises, supply-driven determinants dominate; during periods of technological diffusion following deflationary depressions, demand factors come to the fore. But for middle- and low-income nations, whatever the cross-section and timespan, Tolley's hypothesis is not supported: Coefficients have the wrong sign, suggesting that urban growth is greatest when there are the greatest relative gains in rural productivity, but are statistically insignificant. The need is demonstrated for an urban growth theory that is substantially broader than normally has been modeled, with dynamics that are firmly grounded in an understanding of the periodic structure of economic macrohistory.     

The Analysis of Lin Yutang’s Humor

Lin Yutang is called the master humorist in China.He advocates humor and spiritual literature in his magazine Lun Yu(Analects)which attracts essays and readership.His informal but polished style in both Chinese and English makes him one of the most influential writers of his generation,and his compilations and translations of classic Chinese texts into English are bestsellers in the West.Humor is a distinctive feature in his works.In his book,he uses humor as he sees appropriate,and through humor he criticizes social realities,depicts characters and introduces original expressions,etc.His humor can be related to some aspects in his life.In this paper,I will briefly analysis Lin’s sense of humor and how Lin’applies humor in his works.     

Seismic behavior of two Portuguese adobe buildings: part II —numerical modeling and fragility assessment

Considering the likely unfavorable behavior under seismic action of adobe construction, this article aims at providing a seismic fragility characterization of two adobe Portuguese traditional buildings, using numerical models calibrated over experimental results. The study of such two case-study buildings in the region of Aveiro contributes to the understanding of the seismic fragility of adobe construction in the region in general. The buildings were numerically modeled to estimate their structural behavior under seismic loading using adobe material properties that were calibrated based on the experimental results of a cyclic in-plane test of a full-scale double-Tshaped adobe wall. The method chosen to characterize adobe masonry and model its nonlinear behavior followed a total strain crack-based macro-modeling (TSCM) approach, whereas pushover analysis was carried out to reproduce the pseudo-static experimental test in order to enable a refined calibration of adobe masonry mechanical properties. Fragility functions were then derived, based on the above-mentioned numerical models, using nonlinear static analysis, bringing further insight on the seismic fragility of traditional Portuguese adobe construction.     

A Brief Analysis of Heathcliff in Wuthering Heights

Heathcliff is the protagonist in the great nov-el Wuthering Heights by Emily Bronte.The goal of this paper isto analyze the background,characteristic,and inner world ofHeathcliff.Through the specific and profound analysis,it ex-plains the inevitability of Heathcliff’s tragic love and life.     

An Applied Method for General Regional Seismic Loss Assessment—With A Case Study in Los Angeles County

We describe the formulation and application of an integrated general regional seismic loss assessment (RSLA) method for buildings in seismic regions. An efficient method for RSLA is valuable for engineers involved in city planning, risk management, and insurance dealings. In contrast to previously reported methods, the framework presented herein is hazard-based and utilizes a regional rapid seismic hazard deaggregation tool that allows regional assessment to be conducted more efficiently. The proposed technique is implemented as an example to assess general regional seismic loss in Los Angeles County for a ground motion hazard with 10% probability of exceedance in 50 years.     

Why Do Firms Relocate? Lessons from a Regional Analysis

In recent years, the qualitative evolution of relocations (from low-cost offshoring to more technologically intensive relocations) has become a new concern in political debate. Focusing on these new trends, the aim of this paper is to better understand relocations from the firms’ point of view. The concept of relocation is reformulated by adopting a broad definition considering it as a specific dimension of firms’ mobility options. We consider three analytical dimensions: relocation as a productive problem (“relational space” for coordination), relocation in a territorial dimension (“geographical space”) and relocation as a complex decision-making process (“political space”). On this basis, we combine two strands of literature (economics of proximity and institutional approaches of the firm) for a better understanding of the decision-making process and the resulting diversity of situations. The framework is finally applied to the specific case of the Aquitaine region of southwest France in order to identify the conditions of anchoring and mobility of firms in spatial terms. Our aim is to show that the decision-making process of relocations cannot be reduced to a simple cost calculation, leaving room for local public policies.     

A Content Analysis of Imago Mundi, 1935–2010

ABSTRACT

The 592 research articles in the first 62 volumes of Imago Mundi, from 1935 to 2010, are analysed to discern trends in the scholarly approaches, biases and interests of historians of cartography. Particular attention is paid to map historians’ preferred historical periods and topical subjects of study, to their nationalistic tendencies and to the shifting importance of traditional, internal and socio-cultural approaches to map history.     

The Interpersonal Meaning Analysis of Clinton’s Farewell Speech

From the point of view of the interpersonal function in the theories of Halliday’s systemic functional grammar,this paper uses Clinton’s farewell speech as an example to explain how interpersonal meanings are generally realized in a political speech.Through a brief analysis of linguistic elements on different levels,the lexical,the sentential,we can find that modal auxiliaries and mood are the elements usually used in political speeches to achieve different interpersonal meanings.     

Seismic Assessment of a Historical Masonry Building in Switzerland: The “Ancien Hôpital De Sion”

This article presents the results of the evaluation of the seismic safety of the Ancien Hôpital de Sion, an important Swiss architectural heritage building, situated in the Canton of Valais, the region with the highest seismic hazard in Switzerland. Three-dimensional Applied Element (AEM) modeling of the whole structure has been performed and validated. The adopted modeling strategy, together with nonlinear dynamic analysis, was able to represent the actual behavior and failure mechanisms typical of complex masonry structures, in addition to a good computational efficiency compared to other available numerical approaches. The local collapse mechanisms have been also studied through a kinematic limit analysis based on rigid block rotation. Both linear and nonlinear approaches have been followed together with the capacity spectrum method. The results provided by the different methodologies have been compared with the aim to provide possible insights concerning a general procedure for the assessment of the safety of such type of structures.