Search results for: earthquake disaster

Authors: Stefano Sorace, Gloria Terenzi

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The study of a base isolation seismic retrofit solution for a reinforced concrete school building is presented in this paper. The building was assumed as a benchmark structure for a Research Project financed by the Italian Department of Civil Protection, and is representative of several similar public edifices designed with earlier Technical Standards editions, in Italy as well as in other earthquake-prone European countries. The structural characteristics of the building, and a synthesis of the investigation campaigns developed on it, are initially presented. The mechanical parameters, dimensions, locations and installation details of the base isolation system, incorporating double friction pendulum sliding bearings as protective devices, are then illustrated, along with the performance assessment analyses carried out in original and rehabilitated conditions according to a full non-linear dynamic approach. The results of the analyses show a remarkable enhancement of the seismic response capacities of the structure in base-isolated configuration. This allows reaching the high performance levels postulated in the rehabilitation design with notably lower costs and architectural intrusion as compared to traditional retrofit interventions designed for the same objectives.

Keywords: seismic retrofit, seismic assessment, r/c structures, school buildings, base isolation

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Authors: Jamileh Vasheghani Farahani

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The main purpose of this research is to show the current active faults and active tectonic of the area by three seismic networks in Tehran region: 1-Tehran Disaster Mitigation and Management Organization (TDMMO), 2-Broadband Iranian National Seismic Network Center (BIN), 3-Iranian Seismological Center (IRSC). In this study, we analyzed microearthquakes happened in Tehran city and its surroundings using the Tehran networks from 1996 to 2015. We found some active faults and trends in the region. There is a 200-year history of historical earthquakes in Tehran. Historical and instrumental seismicity show that the east of Tehran is more active than the west. The Mosha fault in the North of Tehran is one of the active faults of the central Alborz. Moreover, other major faults in the region are Kahrizak, Eyvanakey, Parchin and North Tehran faults. An important seismicity region is an intersection of the Mosha and North Tehran fault systems (Kalan village in Lavasan). This region shows a cluster of microearthquakes. According to the historical and microseismic events analyzed in this research, there is a seismic gap in SE of Tehran. The empirical relationship is used to assess the Mmax based on the rupture length. There is a probability of occurrence of a strong motion of 7.0 to 7.5 magnitudes in the region (based on the assessed capability of the major faults such as Parchin and Eyvanekey faults and historical earthquakes).

Keywords: Iran, major faults, microseismicity, Tehran

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Authors: Bang-Fuh Chen, Chih-Chun Chu

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The flow induced cylinder vibration or earthquake-induced cylinder motion are moving in an arbitrary direction with time. The phenomenon of flow across cylinder is highly nonlinear and a linear-superposition of flow pattern across separated oscillating direction of cylinder motion is not valid to obtain the flow pattern across a cylinder oscillating in multiple directions. A novel finite difference scheme is developed to simulate the viscous flow across an arbitrary moving circular cylinder and we call this a complete 2D (two-dimensional) flow-cylinder interaction. That is, the cylinder is simultaneously oscillating in x- and y- directions. The time-dependent domain and meshes associated with the moving cylinder are mapped to a fixed computational domain and meshes, which are time independent. The numerical results are validated by several bench mark studies. Several examples are introduced including flow across steam-wise, transverse oscillating cylinder and flow across rotating cylinder and flow across arbitrary moving cylinder. The Morison’s formula can not describe the complex interaction phenomenon between cross flow and oscillating circular cylinder. And the completed 2D computational fluid dynamic analysis should be made to obtain the correct hydrodynamic force acting on the cylinder.

Keywords: 2D cylinder, finite-difference method, flow-cylinder interaction, flow induced vibration

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Authors: S. Mohamadi, T. Boudina, A. Rouabeh, A. Seridi

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Equivalent linear and non-linear ground response analyses are conducted at many representative sites at the mosque of Algeria, to compare the free field acceleration spectra with local code of practice. Spectral Analysis of Surface Waves (SASW) technique was adopted to measure the in-situ shear wave velocity profile at the representative sites. The seismic movement imposed on the rock is the NS component of Keddara station recorded during the earthquake in Boumerdes 21 May 2003. The site-specific elastic design spectra for each site are determined to further obtain site specific non-linear acceleration spectra. As a case study, the results of site-specific evaluations are presented for two building sites (site of minaret and site of the prayer hall) to demonstrate the influence of local geological conditions on ground response at Algerian sites. A comparison of computed response with the standard code of practice being used currently in Algeria for the seismic zone of Algiers indicated that the design spectra is not able to capture site amplification due to local geological conditions.

Keywords: equivalent linear, non-linear, ground response analysis, design response spectrum

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Authors: Hamid Rostami, Ali Fallah Yeznabad, Mohammad H. Baziar

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The energy-based method for evaluating seismic soil liquefaction has two main sections. First is the demand energy, which is dissipated energy of earthquake at a site, and second is the capacity energy as a representation of soil resistance against liquefaction hazard. In this study, using a statistical analysis of recorded data by 14 down-hole array sites in California, an empirical equation was developed to estimate the demand energy at sites. Because determination of capacity energy at a site needs to calculate several site calibration factors, which are obtained by experimental tests, in this study the standard penetration test (SPT) N-value was assumed as an alternative to the capacity energy at a site. Based on this assumption, the empirical equation was employed to calculate the demand energy for 193 liquefied and no-liquefied sites and then these amounts were plotted versus the corresponding SPT numbers for all sites. Subsequently, a discrimination analysis was employed to determine the equations of several boundary curves for various liquefaction likelihoods. Finally, a comparison was made between the probabilistic model and the commonly used stress method. As a conclusion, the results clearly showed that energy-based method can be more reliable than conventional stress-based method in evaluation of liquefaction occurrence.

Keywords: energy demand, liquefaction, probabilistic analysis, SPT number

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Authors: Kunto Wibowo Agung Prodjonoto

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Occasionally, opportunities occur not due to chances but threats. This, however, is often not realized because a greater threat is perceived to be anything that threatens, endangers, or harms, resulting in bad impacts that are also part of the risk and consequence. As a result, more focus tends to direct towards the bad impacts. Risk, in this case, shall be seen rather as something challenging, which can turn to be an opportunity to tackle an obstacle. Therefore, it does not seem exaggerating if later, risk can be considered as a challenge that presents an opportunity. So as in the context of the threat of natural disasters which gives an idea that opportunities exist. Nature referred to in a fashion as 'natural disasters' captured an expression to picture the 'threats' aspect, which instructively implying a chance of opportunity. This is quite logical, as SWOT (strengths, weaknesses, opportunities, threats) analysis can evaluate the situation at hand related to the analysis of various factors in formulating strategies to deal with natural disaster situations. The analytical method created by Albert Humphrey is indeed not an analytical tool to provide solutions, but certainly 'opportunities and challenges' are discussed therein on a vertical line, where opportunities are posited on the positive axis, and threats are posed on the negative axis. Observing this dynamism, the challenges and threats of disasters are having opportunity relevance to moralizing opportunities, that by quality poses universalism populist characteristics, universalism characteristics, and regional characteristics. Here, universalism appears as an opportunity domain underneath the threats and challenges of natural disasters.

Keywords: universality, opportunities, threats, challenges of natural disasters

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Authors: Jitka Molnarova

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Based on De Soto’s idea that a formal land title can provide a secure home and access to credit to poor urban families, a large number of developing countries accepted the formalization of informal settlements as the ultimate solution for their housing crises and struggles with poverty. After two decades of implementation, very little is known about the effects this policy has on the quality of the neighborhoods it produces and on the development of cities in general. Using the capital of Peru -where the solution originated- as a case study, this paper illustrates the negative outcomes this policy has on urban development arguing that land titling encourages 1) expansion of the city often to areas of high physical risk, 2) production of precarious housing on unserviced land, and 3) practices of illegal land trafficking. The evidence is based on interviews with community leaders and officials working at the Cooperation for Formalization of Informal Property (COFOPRI), comparison of satellite images documenting the expansion of Lima in the past twenty years, and a technical evaluation of dozens of houses that have been or are in the process of being granted a land title.

Keywords: COFOPRI, De Soto, housing policies, land titling, land trafficking, Lima, Peru, precarious housing, urban expansion

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Authors: Didier Birimwiragi Namogo

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The Kivu Lake Basin is located in the Western Branch of the East African Rift. In this basin is located a multitude of active faults, on which earthquakes occur regularly. The most recent earthquakes date from 2008, 2015, 2016, 2017 and 2019. The cities of Bukabu and Goma in DR Congo and Giseyi in Rwanda are the most impacted by this intense seismic activity in the region. The magnitude of the strongest earthquakes in the region is 6.1. The 2008 earthquake was particularly destructive, killing several people in DR Congo and Rwanda. This work aims to complete the distribution of seismicity in the region, deduce areas of weakness and establish a hazard map that can assist in seismic risk management. Using the local seismic network of the Goma Volcano Observatory, the earthquakes were relocated, and their focus mechanism was studied. The results show that most of these earthquakes occur on active faults described by Villeneuve in 1938. The alignment of the earthquakes shows a pace that follows directly the directions of the faults described by this author. The study of the focus mechanism of these earthquakes, also shows that these are in particular normal faults whose stresses show an extensive activity. Such study can be used for the establishment of seismic risk management tools.

Keywords: earthquakes, hazard map, faults, focus mechanism

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Authors: Shahrzad Mohammadi, Ghasem Boshrouei Sharq

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All seismic design codes are based on the determination of the design earthquake without taking into account the effects of aftershocks in the design practice. In regions with a high level of seismicity, the occurrence of several aftershocks of various magnitudes and different time lags is very likely. This research aims to estimate the collapse capacity of a 10-story steel bundled tube moment frame subjected to as-recorded seismic sequences. The studied structure is designed according to the seismic regulations of the fourth revision of the Iranian code of practice for the seismic-resistant design of buildings (Code No.2800). A series of incremental dynamic analyses (IDA) is performed up to the collapse level of the intact structure. Then, in order to demonstrate the effects of aftershock events on the collapse vulnerability of the building, aftershock IDA analyzes are carried out. To gain deeper insight, collapse fragility curves are developed and compared for both series. Also, a study on the influence of various ground motion characteristics on collapse capacity is carried out. The results highlight the importance of considering the decisive effects of aftershocks in seismic codes due to their contribution to the occurrence of collapse.

Keywords: IDA, aftershock, bundled tube frame, fragility assessment, GM characteristics, as-recorded seismic sequences

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Authors: Shi-Yu Xu

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The top three risk factors that have contributed to building collapses during past earthquake events in Taiwan are: "irregular floor plans or elevations," "insufficient columns in single-bay buildings," and the "weak-story problem." Fortunately, these unsound structural characteristics can be directly identified from the floor plans. However, due to the vast number of old buildings, conducting manual inspections to identify these compromised structural features in all existing structures would be time-consuming and prone to human errors. This study aims to develop an algorithm that utilizes artificial intelligence techniques to automatically pinpoint the structural components within a building's floor plans. The obtained spatial information will be utilized to construct a digital structural model of the building. This information, particularly regarding the distribution of columns in the floor plan, can then be used to conduct preliminary seismic assessments of the building. The study employs various image processing and pattern recognition techniques to enhance detection efficiency and accuracy. The study enables a large-scale evaluation of structural vulnerability for numerous old buildings, providing ample time to arrange for structural retrofitting in those buildings that are at risk of significant damage or collapse during earthquakes.

Keywords: structural vulnerability detection, object recognition, seismic capacity assessment, old buildings, artificial intelligence

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Authors: Peter Antwi Buah, Yingbin Zhang, Jianxian He, Chenlin Xiang, Delali Atsu Y. Bakah

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Near-fault ground motions with velocity pulses are considered to cause significant damage to structures or slopes compared to ordinary ground motions without velocity pulses. The double pulsed pulse-like ground motion is as well known to be stronger than the single pulse. This study has numerically justified this perspective by studying the dynamic response of a homogeneous rock slope subjected to four pulse-like and two non-pulse-like ground motions using the Fast Lagrangian Analysis of Continua in 3 Dimensions (FLAC3D) software. Two of the pulse-like ground motions just have a single pulse. The results show that near-fault ground motions with velocity pulses can cause a higher dynamic response than regular ground motions. The amplification of the peak ground acceleration (PGA) in horizontal direction increases with the increase of the slope elevation. The seismic response of the slope under double pulse ground motion is stronger than that of the single pulse ground motion. The PGV amplification factor under the effect of the non-pulse-like records is also smaller than those under the pulse-like records. The velocity pulse strengthens the earthquake damage to the slope, which results in producing a more strong dynamic response.

Keywords: velocity pulses, dynamic response, PGV magnification effect, elevation effect, double pulse

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Authors: Chao Jen-Chih, Hsu Kuo-Wei

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Climate change and natural disasters take effect on urban development. It has been discussed urban renewals can prevent natural disasters. Integrating green infrastructure and urban renewals may have great effect on adapting the impact of climate change. To highlight the economic value of green infrastructure development on urban renewals, some strategies need to be carry on to reduce environmental impact. A number of urban renewals studies has been conducted on right transfer, financial risk, urban renewal policy, and public participation. Little research has been devoted on the subject of the economic value of green infrastructure development on urban renewals. The purpose of this study is to investigate the affecting factors on the economic value of green infrastructure development on urban renewals. This study will present the benefits of green infrastructure development and summarize the critical factors of green infrastructure develop on urban renewals for real essence and non-real essence on economic value from literature. Our results indicate that factors of housing price, land value, floor area incentive, and facilitation of the construction industry affect the outcome of real essence economic value. Factors of enhancement of urban disaster prevention, improvement of urban environment and landscape, crime reduction, climate control, pollution reduction, biological diversity, health impacts, and leisure space affects the outcome of non-real essence economic value.

Keywords: economic value, green infrastructure, urban renewals, urban development

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Authors: Marcelo Jesus Kato Avila, Joao Da Costa Pantoja

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Differential settlement of foundations is a serious pathology in buildings that put at risk lives and property. A common reason for the occurrence of this specific pathology in central Brazil is the presence of collapsible clay, a typical soil in the region. In this study, the foundation of a condemned building erected above this soil is analyzed. The aim is to prevent problems in new constructions, to predict which buildings may be subjected to damages, and to make possible a more precise treatment in less advanced differential settlements observed in the buildings of the vicinity, which includes a hospital, a Military School, an indoor sporting arena, the Police Academy, and the Military Police Headquarters. The methodology consists of visual inspection, photographic report of the main pathologies, analysis of the existing foundations, determination of the soil properties, the study of the cracking level and assessment of structural failure risk of the building. The findings show that the presence of water weaken the soil structure on which the foundation rest, being the main cause of the pathologic settlement, indicating that even in a one store building it was necessary to consider deeper digging, other categories of foundations, and more elaborated and detailed foundation plans when the soil presents this behavior.

Keywords: building cracks, collapsible clay, differential settlement, structural failure risk

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Authors: Tayyaba Hussain, Sobia Jangsher, Saqib Ali, Saqib Ejaz

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Unmanned Aerial vehicles (UAV’s) have gained great popularity due to their remoteness, ease of deployment and high maneuverability in different applications like real-time surveillance, image capturing, weather atmospheric studies, disaster site monitoring and mapping. These applications can involve a real-time communication with the ground station. However, altitude and mobility possess a few challenges for the communication. UAV’s at high altitude usually require more transmit power. One possible solution can be with the use of multi hops (UAV’s acting as relays) and exploiting the mobility pattern of the UAV’s. In this paper, we studied a relay (UAV’s acting as relays) selection for a reliable transmission to a destination UAV. We exploit the mobility information of the UAV’s to propose a Mobility-Aware Relay Selection (MARS) algorithm with the objective of giving improved data rates. The results are compared with Non Mobility-Aware relay selection scheme and optimal values. Numerical results show that our proposed MARS algorithm gives 6% better achievable data rates for the mobile UAV’s as compared with Non MobilityAware relay selection scheme. On average a decrease of 20.2% in data rate is achieved with MARS as compared with SDP solver in Yalmip.

Keywords: mobility aware, relay selection, time division multiple acess, unmanned aerial vehicle

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Authors: Hossein Motaghedi, Kaveh Arkani, Siavash Salamatpoor

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Usually the piles are important tools for safety and economical design of high and heavy structures. For this aim the response of single pile under dynamic load is so effective. Also, the agents which have influence on single pile response are properties of pile geometrical, soil and subjected loads. In this study the finite difference numerical method and by using FLAC 3D software is used for evaluation of single pile behavior under peak ground acceleration (PGA) of El Centro earthquake record in California (1940). The results of this models compared by experimental results of other researchers and it will be seen that the results of this models are approximately coincide by experimental data's. For example the maximum moment and displacement in top of the pile is corresponding to the other experimental results of pervious researchers. Furthermore, in this paper is tried to evaluate the effective properties between soil and pile. The results is shown that by increasing the pile diagonal, the pile top displacement will be decreased. As well as, by increasing the length of pile, the top displacement will be increased. Also, by increasing the stiffness ratio of pile to soil, the produced moment in pile body will be increased and the taller piles have more interaction by soils and have high inertia. So, these results can help directly to optimization design of pile dimensions.

Keywords: pile seismic response, interaction between soil and pile, numerical analysis, FLAC 3D

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Authors: Abdulkerim Ilgun, Ahmad Javid Zia

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In developing countries, the urban populations are increasing rapidly and with this increment the residential areas are experiencing major problems. Construction of high-rise buildings in confined spaces is one of the most practical solutions for this problem. However, by living in high-rise buildings and sharing common residential areas, residents will face many problems. Irritating sound problem which is known as noise is one of the major problems mentioned above. The second most important problem is the weight of the high-rise buildings which makes the structure more vulnerable to earthquakes. To decrease earthquake loads it’s very important to decrease the weight of the buildings. To solve the problem of noise and keep the building weight at minimum level, experimentally designed soundproof gypsum partition wall which has optimum thickness has been used in high-rise story building and the results have been compared with ordinary brick partition walls. In this compression the effect of weights of soundproof gypsum walls and ordinary brick walls in accordance to structural engineering have been investigated.

Keywords: cellubor, gypsum board, gypsum partition walls, light partition walls, noise, sound

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Authors: Atefeh Pourshafie, Homayoun Bakhtiari

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The main task of power distribution companies is to supply the power required by customers in an acceptable level of quality and reliability. Some key performance indicators for electric power distribution companies are those evaluating the continuity of supply within the network. More than other problems, power outages (due to lightning, flood, fire, earthquake, etc.) challenge economy and business. In addition, end users expect a reliable power supply. Reliability indices are evaluated on an annual basis by the specialized holding company of Tavanir (Power Produce, Transmission& distribution company of Iran) . Evaluation of reliability indices is essential for distribution companies, and with regard to the privatization of distribution companies, it will be of particular importance to evaluate these indices and to plan for their improvement in a not too distant future. According to IEEE-1366 standard, there are too many indices; however, the most common reliability indices include SAIFI, SAIDI and CAIDI. These indices describe the period and frequency of blackouts in the reporting period (annual or any desired timeframe). This paper calculates reliability indices for three sample feeders in Lorestan Electric Power Distribution Company and defines the threshold values in a ten-month period. At the end, strategies are introduced to reach the threshold values in order to increase customers' satisfaction.

Keywords: power, distribution network, reliability, outage

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Authors: Bayu Rizky Pratama, Hardiansyah Nur Sahaya

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Riau Province is the worst emitter for forest burning which causes the huge scale of externality such as declining of forest habitat, health disease, and climate change impact. Indonesia forum of budget transparency for Riau Province (FITRA) reported the length of forest burning reached about 186.069 hectares which is 7,13% of total national forest burning disaster, consisted of 107.000 hectares of peatland and the rest 79.069 hectares of mineral land. Anti-fire group, a voluntary group next to the forest, to help in protecting the forest burning and heavily smoke residual has been established but unfortunately the implementation still far from expectation. This research will emphasize on (1) how the anti-fire group contribute to fire hazard tackling; (2) the identification of SWOT analysis to enhance the group benefit; and (3) government policy implication to maximize the role of Anti-fire group and reduce the case of forest burning as well as heavily smoke which can raise climate change impact. As the observation found some weakness from SWOT identification such as (1) lack of education and training; (2) facility in extinguishing the fire damage; (3) law for economic incentive; (4) communication and field experience; (5) also the reporting the fire case.

Keywords: anti-fire group, forest burning impact, SWOT, climate change mitigation

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Authors: Manpreet Singh, V. P. Agrawal, Gurmanjot Singh Bhatti

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From the last decades, there is a significant technological advancement in the field of robotics, and a number of modular self-reconfigurable robots were introduced that can help in space exploration, bucket to stuff, search, and rescue operation during earthquake, etc. As there are numbers of self-reconfigurable robots, choosing the optimum one is always a concern for robot user since there is an increase in available features, facilities, complexity, etc. The objective of this research work is to present a multiple attribute decision making based methodology for coding, evaluation, comparison ranking and selection of modular self-reconfigurable robots using a technique for order preferences by similarity to ideal solution approach. However, 86 attributes that affect the structure and performance are identified. A database for modular self-reconfigurable robot on the basis of different pertinent attribute is generated. This database is very useful for the user, for selecting a robot that suits their operational needs. Two visual methods namely linear graph and spider chart are proposed for ranking of modular self-reconfigurable robots. Using five robots (Atron, Smores, Polybot, M-Tran 3, Superbot), an example is illustrated, and raking of the robots is successfully done, which shows that Smores is the best robot for the operational need illustrated, and this methodology is found to be very effective and simple to use.

Keywords: self-reconfigurable robots, MADM, TOPSIS, morphogenesis, scalability

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Authors: H. K. Ramaraju

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World is in deep trouble and deeper denial. Worse, the denial is now entirely on the side of action. It is well accepted that climate change is a reality. Scientists say we need to cap temperature increases at 2°C to avoid catastrophe, which means capping emissions at 450 ppm .We know global average temperatures have already increased by 0.8°C and there is enough green house gas in the atmosphere to lead to another 0.8°C increase. There is still a window of opportunity, a tiny one, to tackle the crisis. But where is the action? In the 1990’s, when the world did even not understand, let alone accept, the crises, it was more willing to move to tackle climate change. Today we are in reverse in gear. The rich world has realized it is easy to talk big, but tough to take steps to actually reduce emissions. The agreement was that these countries would reduce so that the developing World could increase. Instead, between 1990 and 2006, their carbon dioxide emissions increased by a whopping 14.5 percent, even green countries of Europe are unable to match words with action. Stop deforestation and take a 20 percent advantage in our carbon balance sheet, with out doing anything at home called REDD (reducing emissions from deforestation and forest degradation) and push for carbon capture and storage (CCS) technologies. There are warning signs elsewhere and they need to be read correctly and acted up on , if not the cases like flood –act of nature or manmade disaster. The full length paper orient in proper understanding of the issues and identifying the most appropriate course of action.

Keywords: catastrophe, deforestation, emissions, waste water

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Authors: H. Abbasi, K. Sennah

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A Structural Insulated Panel (SIP) is a structural element contains of foam insulation core sandwiched between two oriented-strand boards (OSB), plywood boards, steel sheets or fibre cement boards. Superior insulation, exceptional strength and fast insulation are the specifications of a SIP-based structure. There are also many other benefits such as less total construction costs, speed of construction, less expensive HVAC equipment required, favourable energy-efficient mortgages comparing to wood-framed houses. This paper presents the experimental analysis on selected foam-timber SIPs to study their structural behaviour when used as walls in residential construction under lateral loading. The experimental program has also taken several stud panels in order to compare the performance of SIP with conventional wood-frame system. The results of lateral tests performed in this study established a database that can be used further to develop design tables of SIP wall subjected to lateral loading caused by wind or earthquake. A design table for walls subjected to lateral loading was developed. Experimental results proved that the tested SIPs are ‘as good as’ the conventional wood-frame system.

Keywords: structural insulated panel, experimental study, lateral load, design tables

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Authors: M. Al-Farttoosi, M. Y. Rafiq, J. Summerscales, C. Williams

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Structures can be subjected to impact loading from various sources like earthquake, tsunami, missiles and explosions. The impact loading can cause different degrees of damage to concrete structures. The demand for strengthening and rehabilitation of damaged structures is increasing. In recent years, Car0bon Fibre Reinforced Polymer (CFRP) matrix composites has gain more attention for strengthening and repairing these structures. To study the impact behaviour of the reinforced concrete (RC) beams strengthened or repaired using CFRP, a heavy impact test machine was designed and manufactured .The machine included a newly designed support system for beams together with various instrumentation. This paper describes the support design configuration of the impact test machine, instrumentation and dynamic analysis of the concrete beams. To evaluate the efficiency of the new impact test machine, experimental impact tests were conducted on simple supported reinforced concrete beam. Different methods were used to determine the impact force and impact response of the RC beams in terms of inertia force, maximum deflection, reaction force and fracture energy. The manufactured impact test machine was successfully used in testing RC beams under impact loading and used successfully to test the reinforced concrete beams strengthened or repaired using CFRP under impact loading.

Keywords: beam, concrete, impact, machine

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Authors: Jayantha Withanaarachchi, Sujeeva Setunge, Sara Moridpour

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Gaps in strategic thinking and planning lead to critical transport infrastructure resilience. These gaps in strategic transport and land use development planning have an impact on communities and cities. Natural and man-induced disasters can be catastrophic to communities. After a disaster, many types of critical infrastructure, including transport infrastructure gets un-usable or gets damaged. This paper examines strategic thinking behind the resilience and protection of Critical Transport Infrastructure (CI) within transport networks by investigating the impact of disasters such as bushfires, hurricanes and earthquakes. A detailed analysis of three case studies have been conducted to identify the gaps in strategic transport planning and strategic decision making processes required to mitigate the impacts of disasters. Case studies will be analysed to identify existing gaps in road design, transport planning and decision making. This paper examines the effect of road designing, transport corridors and decision making during transport planning stages and how it impacts transport infrastructure as well as community resilience. A set of recommendations to overcome the shortcomings of existing strategic planning and designing process are presented. This research paper reviews transport infrastructure planning issues and presents the common approach suitable for future strategic thinking and planning which could be adopted in practices.

Keywords: community resilience, decision making , infrastructure resilience, strategic transport planning, transport infrastructure

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Authors: Rouaz Idriss, Bourahla Nour-Eddine, Kahlouche Farah, Rafa Sid Ali

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The stability of structures made of light-gauge steel depends highly on the contribution of Shear Wall Panel (SWP) systems under horizontal forces due to wind or earthquake loads. Steel plate sheathing is often used with these panels made of cold formed steel (CFS) to improve its shear strength. In order to predict the shear strength resistance, two methods are presented in this paper. In the first method, the steel plate sheathing is modeled with plats strip taking into account only the tension and compression force due to the horizontal load, where both track and stud are modeled according to the geometrical and mechanical characteristics of the specimen used in the experiments. The theoretical background and empirical formulations of this method are presented in this paper. However, the second method is based on a micro modeling of the cold formed steel Shear Wall Panel “CFS-SWP” using Abaqus software. A nonlinear analysis was carried out with an in-plan monotonic load. Finally, the comparison between these two methods shows that the micro modeling with Abaqus gives better prediction of shear resistance of SWP than strips method. However, the latter is easier and less time consuming than the micro modeling method.

Keywords: cold formed steel 'CFS', shear wall panel, strip method, finite elements

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Authors: Shaik Ayesha Fathima, Shaik Noor Jahan, Duvvada Rajeswara Rao

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Earth's environment and its evolution can be seen through satellite images in near real-time. Through satellite imagery, remote sensing data provide crucial information that can be used for a variety of applications, including image fusion, change detection, land cover classification, agriculture, mining, disaster mitigation, and monitoring climate change. The objective of this project is to propose a method for classifying satellite images according to multiple predefined land cover classes. The proposed approach involves collecting data in image format. The data is then pre-processed using data pre-processing techniques. The processed data is fed into the proposed algorithm and the obtained result is analyzed. Some of the algorithms used in satellite imagery classification are U-Net, Random Forest, Deep Labv3, CNN, ANN, Resnet etc. In this project, we are using the DeepLabv3 (Atrous convolution) algorithm for land cover classification. The dataset used is the deep globe land cover classification dataset. DeepLabv3 is a semantic segmentation system that uses atrous convolution to capture multi-scale context by adopting multiple atrous rates in cascade or in parallel to determine the scale of segments.

Keywords: area calculation, atrous convolution, deep globe land cover classification, deepLabv3, land cover classification, resnet 50

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Authors: Yunus Dere

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Minarets are tower like structures where the call to prayer of Muslims is performed. They have a symbolic meaning and sacred place among Muslims. Being tall and slender, they are prone to damage under earthquakes and strong winds. Kursuncular stone minaret was built around thirty years ago in Konya/TURKEY. Its core and helical stairs are made of reinforced concrete. Its stone spire was damaged during a light earthquake. Its spire is later replaced with a light material covered with lead sheets. In this study, the natural frequencies and mode shapes of Kursuncular minaret is obtained experimentally and analytically. First an ambient vibration test is carried out using a data acquisition system with accelerometers located at four locations along the height of the minaret. The collected vibration data is evaluated by operational modal analysis techniques. For the analytical part of the study, the dimensions of the minaret are accurately measured and a detailed 3D solid finite element model of the minaret is generated. The moduli of elasticity of the stone and concrete are approximated using the compressive strengths obtained by Windsor Pin tests. Finite element modal analysis of the minaret is carried out to get the modal parameters. Experimental and analytical results are then compared and found in good agreement.

Keywords: experimental modal analysis, stone minaret, finite element modal analysis, minarets

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Authors: Nicolò Vaiana, Giorgio Serino

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The nonlinear time history analysis of seismically base-isolated structures can require a significant computational effort when the behavior of each seismic isolator is predicted by adopting the widely used differential equation Bouc-Wen model. In this paper, a nonlinear exponential model, able to simulate the response of seismic isolation bearings within a relatively large displacements range, is described and adopted in order to reduce the numerical computations and speed up the nonlinear dynamic analysis. Compared to the Bouc-Wen model, the proposed one does not require the numerical solution of a nonlinear differential equation for each time step of the analysis. The seismic response of a 3d base-isolated structure with a lead rubber bearing system subjected to harmonic earthquake excitation is simulated by modeling each isolator using the proposed analytical model. The comparison of the numerical results and computational time with those obtained by modeling the lead rubber bearings using the Bouc-Wen model demonstrates the good accuracy of the proposed model and its capability to reduce significantly the computational effort of the analysis.

Keywords: base isolation, computational efficiency, nonlinear exponential model, nonlinear time history analysis

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Authors: Allaeddine Athmani, Abdelhacine Gouasmia, Tiago Ferreira, Romeu Vicente

Abstract:

The seismic risk mitigation from the perspective of the old buildings stock is truly essential in Algerian urban areas, particularly those located in seismic prone regions, such as Annaba city, and which the old buildings present high levels of degradation associated with no seismic strengthening and/or rehabilitation concerns. In this sense, the present paper approaches the issue of the seismic vulnerability assessment of old masonry building stocks through the adaptation of a simplified methodology developed for a European context area similar to that of Annaba city, Algeria. Therefore, this method is used for the first level of seismic vulnerability assessment of the masonry buildings stock of the old city center of Annaba. This methodology is based on a vulnerability index that is suitable for the evaluation of damage and for the creation of large-scale loss scenarios. Over 380 buildings were evaluated in accordance with the referred methodology and the results obtained were then integrated into a Geographical Information System (GIS) tool. Such results can be used by the Annaba city council for supporting management decisions, based on a global view of the site under analysis, which led to more accurate and faster decisions for the risk mitigation strategies and rehabilitation plans.

Keywords: Damage scenarios, masonry buildings, old city center, seismic vulnerability, vulnerability index

Procedia PDF Downloads 428

Authors: M. H. Mehrabi, S. S. Ghodsi, Zainah Ibrahim, Meldi Suhatril

Abstract:

Standard routes for upgrading existing buildings to improve their seismic response can be expensive in terms of both time and cost due to the modifications required to the foundations. As a result, interest has grown in the installation of viscoelastic dampers (VEDs) in mid and high-rise buildings. Details of a low-cost viscoelastic passive control device, the rotary rubber braced damper (RRBD), are presented in this paper. This design has the added benefits of being lightweight and simple to install. Experimental methods and finite element modeling were used to assess the performance of the proposed VED design and its effect on building response during earthquakes. The analyses took into account the behaviors of non-linear materials and large deformations. The results indicate that the proposed RRBD provides high levels of energy absorption, ensuring the stable cyclical response of buildings in all scenarios considered. In addition, time history analysis was employed in this study to evaluate the RRBD’s ability to control the displacements and accelerations experienced by steel frame structures. It was demonstrated that the device responds well even at low displacements, highlighting its suitability for use in seismic events of varying severity.

Keywords: dynamic response, passive control, performance test, seismic protection

Procedia PDF Downloads 154

Authors: Oyenike Eludoyin

Abstract:

Extreme climate conditions are deviation from the norms and are capable of causing upsets in many important environmental parameter including disruption of water balance and air temperature balance. Studies have shown that extreme climate conditions can foretell disaster in regions with inadequate early warning systems. In this paper, we combined geographical information systems, statistics and social surveys to evaluate the physiologic indices [(Dewpoint Temperature (Td), Effective Temperature Index (ETI) and Relative Strain Index (RSI)] and extreme climate conditions in different parts of southwest Nigeria. This was with the view to assessing the nature and the impact of the conditions on the people and their coping strategies. The results indicate that minimum, mean and maximum temperatures were higher in 1960-1990 than 1991-2013 periods at most areas, and more than 80% of the people adapt to thermal stress by changing wear type or cloth, installing air conditioner and fan at home and/or work place and sleeping outside at certain period of the night and day. With respect to livelihoods, about 52% of the interviewed farmers indicated that too early rainfall, late rainfall, prolonged dryness after an initial rainfall, excessive rainfall and windstorms caused low crop yields. Main (76%) coping strategies were changing of planting dates, diversification of crops, and practices of mulching and intercropping. Government or institutional support was less than 20%.

Keywords: coping strategies, extreme climate, livelihoods, physiologic comfort

Procedia PDF Downloads 258