Spelling suggestions: "subject:"[een] RETROFIT"" "subject:"[enn] RETROFIT""
131 |
Comparison Of Seismic Assessment Procedures In The Current Turkish CodeOkur, Abdullah 01 December 2007 (has links) (PDF)
In Turkey, most of the existing buildings are vulnerable to earthquakes due to their poor material quality and inaccurate design. Besides, so many destructive earthquakes occurred in the past, because Turkey is located on a seismically active region. Therefore, existing buildings should be assessed and necessary precautions should be taken before a probable earthquake. To assess seismic performance of the existing buildings, the 2007 Turkish Earthquake Code offers two methods which are linear and nonlinear. For linear assessment, members are controlled by comparing the force demands and capacities where for nonlinear assessment, strains corresponding to the plastic rotations of the members are compared with the limits given in the code.
In this study, the building, which stands in Bakirkö / y district of istanbul, was assessed according the linear elastic and nonlinear static procedures given in the 2007 Turkish Earthquake Code. In addition, it was retrofitted by adding shear walls to the structural system and same assessment procedures were performed. In the last case study, building is re-designed according to the code and re-assessed. Comparative results and conclusions were summarized in the last chapter.
|
132 |
Seismic Upgrading Of Reinforced Concrete Frames With Structural Steel ElementsOzcelik, Ramazan 01 June 2011 (has links) (PDF)
This thesis examines the seismic internal retrofitting of existing deficient reinforced concrete
(RC) structures by using structural steel members. Both experimental and numerical studies
were performed. The strengthening methods utilized with the scope of this work are chevron
braces, internal steel frames (ISFs), X-braces and column with shear plate. For this purpose,
thirteen strengthened and two as built reference one bay one story portal frame specimens
having 1/3 scales were tested under constant gravity load and increasing cyclic lateral
displacement excursions. In addition, two ½ / scaled three bay-two story frame specimens
strengthened with chevron brace and ISF were tested by employing continuous pseudo
dynamic testing methods. The test results indicated that the cyclic performance of the Xbrace
and column with shear plate assemblage technique were unsatisfactory. On the other
hand, both chevron brace and ISF had acceptable cyclic performance and these two
techniques were found to be candidate solutions for seismic retrofitting of deficient RC
structures. The numerical simulations by conducting nonlinear static and dynamic analysis
were used to estimate performance limits of the RC frame and steel members. Suggested
strengthening approaches, chevron brace and ISF, were also employed to an existing five
story case study RC building to demonstrate the performance efficiency. Finally, design
approaches by using existing strengthening guidelines in Turkish Earthquake Code and
ASCE/SEI 41 (2007) documents were suggested.
|
133 |
Seismic fragility and retrofitting for a reinforced concrete flat-slab structureBai, Jong-Wha 30 September 2004 (has links)
The effectiveness of seismic retrofitting applied to enhance seismic performance was assessed for a five-story reinforced concrete (RC) flat-slab building structure in the central United States. In addition to this, an assessment of seismic fragility that relates the probability of exceeding a performance level to the earthquake intensity was conducted. The response of the structure was predicted using nonlinear static and dynamic analyses with synthetic ground motion records for the central U.S. region. In addition, two analytical approaches for nonlinear response analysis were compared. FEMA 356 (ASCE 2000) criteria were used to evaluate the seismic performance of the case study building. Two approaches of FEMA 356 were used for seismic evaluation: global-level and member-level using three performance levels (Immediate Occupancy, Life Safety and Collapse Prevention). In addition to these limit states, punching shear drift limits were also considered to establish an upper bound drift capacity limit for collapse prevention. Based on the seismic evaluation results, three possible retrofit techniques were applied to improve the seismic performance of the structure, including addition of shear walls, addition of RC column jackets, and confinement of the column plastic hinge zones using externally bonded steel plates. Finally, fragility relationships were developed for the existing and retrofitted structure using several performance levels. Fragility curves for the retrofitted structure were compared with those for the unretrofitted structure. For various performance levels to assess the fragility curves, FEMA global drift limits were compared with the drift limits based on the FEMA member-level criteria. In addition to this, performance levels which were based on additional quantitative limits were also considered and compared with FEMA drift limits.
|
134 |
Agent-based modeling of commercial building stocks for energy policy and demand response analysisZhao, Fei 04 April 2012 (has links)
Managing a sustainable built environment with a large number of buildings rests on the ability to assess and improve the performance of the building stock over time. Building stock models are cornerstones to the assessment of the combined impact of energy-related building interventions across different spatial and temporal scales. However, such models, particularly those accounting for both physical formulation and social behaviors of the underlying buildings, are still in their infancy. This research strives to more thoroughly examine how buildings perform aggregately in energy usage by focusing on how to tackled three major technical challenges: (1) quantifying building energy performance in an objective and scalable manner, (2) mapping building stock model space to real-world data space, and (3) quantifying and evaluating energy intervention behaviors of a building stock. This thesis hypothesizes that a new paradigm of aggregation of large-scale building stocks can lead to (1) an accurate and efficient intervention analysis model and (2) a functionally comprehensive decision support tool for building stock energy intervention analysis. Specifically, this thesis presents three methodologies. To address the first challenge, this thesis develops a normative building physical energy model that can rapidly estimate single building energy performance with respect to its design and operational characteristics. To address the second challenge, the thesis proposes a statistical procedure using regression and Markov chain Monte Carlo (MCMC) sampling techniques that inverse-estimate building parameters based on building stock energy consumption survey data. The outcomes of this statistical procedure validate the approach of using prototypical buildings for two types of intervention analysis: energy retrofit and demand response. These two cases are implemented in an agent-based modeling and simulation (ABMS) framework to tackle the third challenge. This thesis research contributes to the body of knowledge pertaining to building energy modeling beyond the single building scale. The proposed framework can be used by energy policy makers and utilities for the evaluation of energy retrofit incentives and demand-response program economics.
|
135 |
Blast Retrofit of Reinforced Concrete Walls and SlabsJacques, Eric 01 March 2011 (has links)
Mitigation of the blast risk associated with terrorist attacks and accidental explosions threatening critical infrastructure has become a topic of great interest in the civil engineering community, both in Canada and abroad. One method of mitigating blast risk is to retrofit vulnerable structures to resist the impulsive effects of blast loading. A comprehensive re-search program has been undertaken to develop fibre reinforced polymer (FRP) retrofit methodologies for structural and non-structural elements, specifically reinforced concrete slabs and walls, subjected to blast loading. The results of this investigation are equally valid for flexure dominant reinforced concrete beams subject to blast effects. The objective of the research program was to generate a large volume of research data for the development of blast-resistant design guidelines for externally bonded FRP retrofit systems. A combined experimental and analytical investigation was performed to achieve the objectives of the program.
The experimental program involved the construction and simulated blast testing of a total of thirteen reinforced concrete wall and slab specimens divided into five companion sets. These specimens were subjected to a total of sixty simulated explosions generated at the University of Ottawa Shock Tube Testing Facility. Companion sets were designed to study one- and two-way bending, as well as the performance of specimens with simply-supported and fully-fixed boundary conditions. The majority of the specimens were retrofitted with externally bonded carbon fibre reinforced polymer (CFRP) sheets to improve overall load-deformation characteristics. Specimens within each companion set were subjected to progressively increasing pressure-impulse combinations to study component behaviour from elastic response up to inelastic component failure. The blast performance of companion as-built and retrofitted specimens was quantified in terms of measured load-deformation characteristics, and observed member behaviour throughout all stages of response. The results show that externally bonded FRP retrofits are an effective retrofit technique to improve the blast resistance of reinforced concrete structures, provided that debonding of the composite from the concrete substrate is prevented. The test results also indicate that FRP retrofitted reinforced concrete structures may survive initial inbound displacements, only to failure by moment reversals during the negative displacement phase.
The experimental test data was used to verify analytical techniques to model the behaviour of reinforced concrete walls and slabs subjected to blast loading. The force-deformation characteristics of one-way wall strips were established using inelastic sectional and member analyses. The force-deformation characteristics of two-way slab plates were established using commonly accepted design approximations. The response of all specimens was computed by explicit solution of the single degree of freedom dynamic equation of motion. An equivalent static force procedure was used to analyze the response of CFRP retrofitted specimens which remained elastic after testing. The predicted maximum displacements and time-to-maximum displacements were compared against experimental results. The analysis indicates that the modelling procedures accurately describe the response characteristics of both retrofitted and unretrofitted specimens observed during the experiment.
|
136 |
Developing whole-life cost models for retrofit options in office buildingsTokede, Olubukola O. January 2016 (has links)
Office retrofit building projects have become a subject of increased attention among building researchers in the United Kingdom, and in many economically advanced nations. Existing whole-life costing models have however, not proven to be robust enough to deal with these retrofit building scenarios. There is a growing body of evidence that conceptual modifications in the mechanics of whole-life cost modelling, could facilitate improvements in the long-term cost assessment of buildings. Recent research has made a case for the existence of revocability and disruption, in the appraisal of retrofit building investments. Revocability, connotes the potential for variability, in the future cost projections of a building over its estimated life. Disruption relates to the diminished building use, or unusability, over a period of implementing a retrofit initiative. Existing whole-life cost models have however, not recognised the implications of revocability and disruption in their framework. This study conducts an investigation into the whole-life costing of office retrofit building projects, and develops a Fuzzy New-Generation Whole-life Costing approach. Two office retrofit building projects are adopted, to appraise the identified issues in the whole-life costing framework. A number of building configuration permutations (BCPs) constituting different retrofit options, are developed in both projects. The potential implication of revocability and disruption, are evaluated based on probability and fuzzy logic principles respectively. Sensitivity analysis is applied to discount rate assumptions over the estimated lives, of the projects considered. The Spearman's rank correlation coefficient is used in analysing the ranking results of selected projects. This provided an assessment of the relative preference of BCPs in the projects. Results from the case studies show 1) disruption issues account for up to 12% of initial capital costs; 2) revocability accounts for up to 35% of initial capital cost, over a 20-year life; up to 119%, over a 60-year life; 3) up to 2% underestimation in the whole-life cost, over a 20-year life; and up to 45% underestimation, over a 60-year period, in the SPACE project; 4) up to 9% underestimation in the whole-life cost, over a 20-year life; and up to 53% underestimation, over a 60-year life, in the MS project.
|
137 |
Energy Audit of an industrial building in Sweden : Case study of a CNC processed components’ producer companyBueno Rosete, Isabel January 2018 (has links)
The industrial sector accounts for almost 40 % of the Swedish energy use and in order to meet the EU’s 2020 targets, an efficient production of high quality and great finish goods are more and more in demand. Moreover, it is important to develop the activities with the lowest environmental impact possible. The energy audit process is an effective tool to achieve it. Thus, in this document the energy audit of an industrial company, Automat Industrier in Gävle, Sweden, was carried out. The energy balance of the building and the potential energy efficiency measures were analyzed with the IDA ICE simulation. The proposed energy retrofitting was apropos of the building envelope, the lighting system, the ventilation system and the installation of a PV system on the roof of the building. The survey indicated that the potential energy savings of the company accounted for 62.5 % of the current electricity use and 48.8 % of the current DH use if all the proposed ameliorations were performed. The main promoter of the electricity savings is the installation of the PV system, with 85 % of influence. Almost 90 % of the DH savings are due to the measures in the ventilation system. Financially, these savings can reach the amounts of 531 597 SEK/year for electricity and 174 201 SEK/year for DH. Nevertheless, the ameliorations regarding the building envelope have very long payback periods. Thus, it was recommended to not pursue them. Fortunately, the energy efficiency measures providing the greatest savings’ payback periods are between 3.47 years and 10.22 years long. As they are independent from each other, the owner has the freedom to decide whether to apply them or not and when if so.
|
138 |
Retrofit electrochromic glazing : a longitudinal case study of occupant experienceWaskett, Ruth Kelly January 2016 (has links)
Electrochromic (EC) glazing has emerged as an alternative to traditional forms of glazing. It has the potential to enable occupants to control daylight ingress without the use of blinds, giving users more access to daylight with all its inherent benefits. Research efforts to date have been mainly focussed on the potential of EC glazing as an energy saving technology through the reduction of electric lighting and air conditioning energy loads, using scale models, computer simulations and full scale test rooms. Few studies have considered the user experience of the technology, and none of the studies that have included data from human participants have been carried out in a real-world research setting over a long-term period. Thus, there is a general lack of understanding regarding the performance and suitability of EC glazing in real-world working environments. To address this gap in research, a new study of EC glazing was undertaken, looking at the experience of occupants working in an office that had been retrofitted with EC-glazed windows. The retrofit was the first of its kind in the UK, and provided an opportunity to study the user experience of EC glazing in a real-world setting over a longitudinal period. The aims of the study were to gain new insights into the experience of users of EC glazing, and to learn about the practicalities of installing it. A number of research questions were defined, leading to a mixed methods data collection programme, carried out over a period of almost 18 months. The data collection encompassed data from the occupants as well as from the physical environment, and was designed in response to the constraints of the site and occupants, as well as the aims of the research enquiry. The resulting data set includes a valuable record of occupant experiences and behaviour, as well as detailed information about environmental conditions at key times. A number of contextual factors influencing the effectiveness of EC glazing were identified. The outcomes of this research provide a new understanding of the user experience of EC glazing, and thus can inform further technological development and benefit future installations.
|
139 |
La ventilation naturelle dans la réhabilitation de bâtiments de bureaux en milieu urbain dense : défis et potentiel / Natural Ventilation in office building retrofit in dense urban context : challenges and potential / A ventilação natural na reabilitação de edificios de escritoriós : desafios e potencialidadesRamalho fontenelle, Marilia 30 March 2016 (has links)
À présent, la réhabilitation des bâtiments est entendue comme une opportunité d’adapter les immeubles existants aux transformations urbaines. Ces modifications ont un impact sur la performance environnementale du parc immobilier, et la ventilation naturelle est l’un des aspects les plus affectés. La densification du tissu urbain est responsable, dans certains cas, de la réduction de la vitesse de l’air, qui peut rendre difficile la dissipation de la chaleur, du bruit et des polluants. Sous un climat chaud et humide, ces facteurs provoquent fréquemment l’adoption d’une climatisation mécanique, surtout dans les bâtiments de bureaux. Étant donné l’importance du sujet, ce travail a pour objectif de discuter les défis et le potentiel d’adopter la ventilation naturelle dans les projets de réhabilitation des bâtiments de bureaux en milieu urbain dense. On soutient l’hypothèse que le projet de réhabilitation peut promouvoir l'utilisation efficace de la ventilation naturelle dans les bâtiments de bureaux, à travers son adéquation au contexte urbain et environnemental présent. La demarche adoptée est composée de quatre étapes. Tout d’abord, on effectue une revue de la littérature sur la réhabilitation des bâtiments pour comprendre le contexte spécifique sur lequel on travaille le thème de la «ventilation naturelle». Ensuite, on analyse l’état de l'art sur la ventilation naturelle dans le cadre de la réhabilitation dans les contextes nationaux et internationaux afin d'identifier les avancées atteintes. Après, on réalise une revue de la littérature sur les effets de l'urbanisation sur l’écoulement de l’air. Pour clore, on propose une réhabilitation d’un bâtiment de bureaux dans le centre-ville de Rio de Janeiro, qui permettra de vérifier les bénéfices d’une solution de ventilation pour le confort des occupants. Le travail souligne la complexité de trouver des solutions de réhabilitation qui permettent d’augmenter le débit d’air dans les bâtiments tout en conciliant l’intégralité de leur patrimoine architectural, l’adaptation aux nécéssités présentes et la possibilité des transformations futures. Le défi augmente dans les milieux urbains denses, où le bruit, la pollution de l’air et la faible perméabilité du tissu urbain peuvent poser des limitations. Dans le cadre des recherches en Europe, Asie et Amérique du Nord, plusieurs réhabilitations ont été réalisées pour analyser la performance des solutions de ventilation. Les ventilations hybride et nocturne sont les plus indiquées. Au Brésil, les recherches sur ce sujet restent balbutiantes et la climatisation mécanique est la solution 9 prédominante dans les rénovations des espaces corporatifs. L’étude de cas montre, à l’aide des modélisations CFD, que la densification de la région analysée a réduit la vitesse et le débit d’air des étages et, par conséquent, a diminué les heures de confort thermique. Les étages plus bas sont les moins favorisés par le vent et le bruit. Ce diagnostic montre la nécessité d’amplifier le débit d’air du bâtiment pendant son occupation et de rendre possible la ventilation nocturne pour dissiper la chaleur accumulée pendant la journée. Dans ce sens, on propose l’ouverture de la partie fixe supérieure de toutes les fênetres, une intervention qui préserve les caractéristiques originales des façades et ne nuit pas à la sécurité du bâtiment lorsqu’il est inoccupé. Les résultats indiquent que cette intervention a augmenté les heures de confort thermique des occupants entre 0,5 et 35%, selon l’étage et de l’indicateur utilisé dans l’interprétation des résultats. Cela renforce l’hypothèse que la ventilation naturelle, toute seule, n’est pas sufisante pour préserver le confort des occupants pendant toute l’année. Cependant, elle peut être complétée par la ventilation mécanique, a fin de concilier le bien-être des usagers et la réduction de la consommation d’énergie des bâtiments / Nowadays, retrofitting is understood as an opportunity to adapt existing buildings to the urban transformations of its surroundings. The changes in the urban fabric can cause impacts to the building environmental performance and, generally, natural ventilation is one of the most affected aspects. The densification process is responsible, in some cases, for the reduction of wind speed, which can disturb the dissipation of heat, noise and pollutants. In hot and humid climate, these factors cause frequently the adoption of mechanical ventilation, mainly in office buildings. Given the relevance of the subject, this work aims to discuss the challenges and potential of adopting natural ventilation in the retrofit of office buildings located in dense urban areas. Our hypothesis is that the retrofit project can promote the efficient use of natural ventilation in office buildings, through its adaptation to the present urban and environmental conditions. The methodology includes 4 stages. First, we carry out a literature review about building retrofits to understand the specific context with which we are dealing the subject of “natural ventilation”. Next, we analyze the state of the art of natural ventilation in the retrofit context to identify the main findings. Then, we investigate the effects of urbanization on the airflow pattern. Finally, we propose retrofitting an office building in downtown Rio de Janeiro to verify the benefits offered by a ventilation solution to the occupants’ thermal comfort. We highlight the complexity of developing solutions that increase the airflow in buildings while balancing the protection of its past, the response to the present requirements and the possibility of future changes. This challenge increases in dense urban areas, where noise, air pollution and low permeability of the urban fabric can place some limitations. As part of the research carried out by European, Asian and North American countries, several renovations were conducted to analyze the performance of ventilation solutions. Hybrid and night ventilation were indicated as the most appropriate ones. In Brazil, investigations in this subject remain incipient and air conditioning is the predominant solution in office spaces. By means of CFD simulations, the case study shows that the densification of the analyzed region reduced the wind speed and airflow in all floors and, therefore, reduced the thermal comfort hours. The lower floors are the least favored by the wind and the noise. This diagnostic points out the need to increase buildings airflow during its occupancy and allow night ventilation to dissipate the heat gains accumulated during the day. In this way, we propose to open the upper fixed 11 portion of all windows, a solution that protects the original façade features and do not harm the buildings security when it is not occupied. Thermal simulations indicate that this procedure increases the thermal comfort annual hours in 0,5-35%, depending on the floor and the adaptive comfort model used to interpret the results. We conclude that natural ventilation itself is not sufficient to ensure occupants comfort throughout the year, however it can be complemented by mechanical ventilation in order to balance thermal comfort and energy efficiency. / Atualmente, a reabilitação é entendida como uma oportunidade de adaptar os edifícios existentes às transformações urbanas sofridas pelo entorno. Tais modificações geram impactos ao desempenho ambiental do imóvel, e a ventilação natural é um dos aspectos mais afetados. O adensamento do tecido urbano é responsável, em alguns casos, pela redução da velocidade do ar, que pode dificultar a dissipação do calor, ruído e poluentes. Nos climas quentes e úmidos, esses fatores provocam frequentemente a adoção de refrigeração mecânica, especialmente em edifícios de escritórios. Dada a relevância do tema, este trabalho tem por objetivo discutir os desafios e potencialidades de adotar a ventilação natural no projeto de reabilitação de edifícios de escritórios situados em meios urbanos densos. Assume-se como hipótese que o projeto de reabilitação pode promover uma utilização eficiente da ventilação natural nos edifícios de escritórios, por meio de sua adequação ao contexto urbano presente. A metodologia adotada é composta por quatro etapas. Inicialmente, realiza-se uma revisão bibliográfica sobre a reabilitação de edifícios a fim de compreender o contexto específico sobre o qual será trabalhado o tema da ventilação natural. Em seguida, analisa-se o estado-da-arte da ventilação natural no contexto da reabilitação, buscando identificar os principais avanços obtidos no cenário nacional e internacional. Depois, efetua-se uma revisão da literatura sobre os efeitos da urbanização no escoamento do ar. Finalmente, propõe-se uma reabilitação de um edifício de escritórios no centro do Rio de Janeiro, para verificar os benefícios de uma solução de ventilação no conforto dos ocupantes. O trabalho destaca a complexidade de desenvolver soluções reversíveis que possibilitem aumentar a vazão de ar nos edifícios e preservar suas características construtivas. O desafio é ainda maior em meios urbanos densos, onde o ruído, a poluição do ar e a baixa permeabilidade do tecido urbano podem impor limitações. As pesquisas desenvolvidas na Europa, Ásia e América do Norte destacam as ventilações híbrida e noturna como as soluções mais indicadas. No Brasil, os trabalhos sobre o tema ainda são incipientes, e a refrigeração mecânica é a solução predominante nas reabilitações de espaços corporativos. O estudo de caso indica, por meio de simulações fluidodinâmicas e térmicas, que a densificação da área analisada reduziu a velocidade e vazão do ar no edifício, diminuindo as horas de conforto térmico. Os pavimentos7mais baixos são os menos favorecidos pelos ventos e ruído. Este diagnóstico indica a necessidade de aumentar a vazão de ar durante a ocupação e viabilizar a ventilação noturna para dissipar o calor acumulado durante o expediente. Neste sentido, propõe-se a abertura das folhas fixas sobre as janelas existentes, o que não compromete a preservação das características originais das fachadas e a segurança do edifício quando desocupado. Os resultados indicam que esta intervenção aumenta entre 0,5 e 35% as horas de conforto dos ocupantes. Conclui-se que a ventilação natural, por si só, não satisfaz o conforto térmico durante o ano todo, mas pode ser complementada pela ventilação mecânica, de modo a conciliar eficiência energética e bem-estar dos usuários.
|
140 |
Robust Seismic Vulnerability Assessment Procedure for Improvement of Bridge Network PerformanceCorey M Beck (9178259) 28 July 2020 (has links)
<div>Ensuring the resilience of a state’s transportation network is necessary to guarantee an acceptable quality of life for the people the network serves. A lack of resilience in the wake of a seismic event directly impacts the states’ overall safety and economic vitality. With the recent identification of the Wabash Valley Seismic Zone (WBSV), Department of Transportations (DOTs) like Indiana’s have increased awareness for the vulnerability of their bridge network. The Indiana Department of Transportation (INDOT) has been steadily working to reduce the seismic vulnerability of bridges in the state in particular in the southwest Vincennes District. In the corridor formed by I-69 built in the early 2000s the bridge design is required to consider seismic actions. However, with less recent bridges and those outside the Vincennes District being built without consideration for seismic effects, the potential for vulnerability exists. As such, the objective of this thesis is to develop a robust seismic vulnerability assessment methodology which can assess the overall vulnerability of Indiana’s critical bridge network. </div><div><br></div><div>A representative sample of structures in Indiana’s bridge inventory, which prioritized the higher seismic risk areas, covered the entire state geographically, and ensured robust superstructure details, was chosen. The sample was used to carry a deterministic seismic vulnerability assessment, applicable to all superstructure-substructure combinations. Analysis considerations, such as the calculation of critical capacity measures like moment-curvature and a pushover analysis, are leveraged to accurately account for non-linear effects like force redistribution. This effect is a result of non-simultaneous structural softening in multi-span bridges that maintain piers of varying heights and stiffnesses. These analysis components are incorporated into a dynamic analysis to allow for the more precise identification of vulnerable details in Indiana’s bridge inventory.</div><div><br></div><div>The results of this deterministic seismic assessment procedure are also leveraged to identify trends in the structural response of the sample set. These trends are used to identify limit state thresholds for the development of fragility functions. This conditional probabilistic representation of bridge damage is coupled with the probability of earthquake occurrence to predict the performance of the structure for a given return period. This probabilistic approach alongside a Monte Carlo simulation is applied to assess the vulnerability of linked bridges along key-access corridors throughout the state. With this robust seismic vulnerability methodology, DOTs will have the capability of identifying vulnerable corridors throughout the state allowing for the proactive prioritization of retrofits resulting in the improved seismic performance and resiliency of their transportation network.</div>
|
Page generated in 0.0451 seconds