Earthquake Resistant Buildings Research Articles

Uganda at Glance of 5.7 Magnitude Earthquake: Lessons for Earthquake Risk Reduction.

Introduction: Uganda remains seismically vulnerable to earthquakes, which constitute one of the most deadly naturally triggered disasters in the world. This is not surprising given the country’s location in the East African Rift Valley System.Method: This paper draws mainly on the authors’ live event experience and some media reports to narratively outline the nature of a sizable earthquake, which measured a magnitude of 5.7 on the Richter scale that struck Uganda and other countries within the Lake Victoria Basin region on 10th September 2016 in the afternoon.Results: Rakai - a district in central region was the worst affected in Uganda. It witnessed the death of four people; 20 people were admitted to the hospital with injuries; a total of 590 people were affected; and serious structural damages mainly in buildings were reported, leaving many either razed to the ground or left with cracks.Discussions: Although this earthquake was less devastating in terms of injuries and fatalities compared to two previous earthquakes in Uganda, based on the Modified Mercalli Intensity Scale it was still considered to be severe. Therefore, this paper identified some proactive lessons as far as earthquake risk reduction in Uganda is concerned, which among others include: encouraging earthquake-resistant buildings; the safety of essential infrastructure; earthquake early warning systems supported by free global technologies; and the safety of rescue workers along with prioritizing the psychosocial needs of rescue teams. With all this in mind, the September 2016 earthquake should serve as a timely reminder that there is a real need for the proactive ex-ante earthquake preparedness rather than risking an expensive post-ante approach to responding to any future devastating earthquakes in Uganda.Keywords: Earthquake, Uganda, disaster risk reduction, ex-ante approach, post-ante approach

Optimum Earthquake Design Coefficients Based on Probabilistic Seismic Hazard Analyses: Theory and Applications

It is common practice to define the seismic design coefficients for earthquake-resistant building codes by choosing a fixed return period, leaving aside considerations about structural vulnerability and acceptable risk levels. This paper reviews the theory of the optimum design, introduced from almost the beginning of the formal probabilistic seismic hazard analysis framework and presents the results of its application in Mexico and Colombia using national seismic hazard models for the two countries. The obtained optimum design coefficients are compared with the ones obtained with the fixed return period approach. Results are presented with the aim of starting to discuss alternative approaches to select, in a more sensible way, the seismic design values included in the building codes.

Development of Nationwide Vs30 Map and Calibrated Conversion Table for Indonesia using Automated Topographical Classification

A nationwide Vs30 map for Indonesia was developed based on automated topographic classification from 90-m grid digital elevation data and their correlation with Vs30. Automated topographic classification has been proposed by Iwahashi and Pike (2007) and a procedure to convert topographic class into Vs30 maps has been developed by Imamura and Furuta (2015) based on Vs data from J-SHIS (Japan Seismic Hazard Information System). In order to be suitable for Indonesia, calibration work according to Imamura and Furuta's procedure should be conducted since the geotechnical conditions in Japan may not be the same as in Indonesia. This paper presents adjustment of the Vs30 correlation by Imamura and Furuta to convert topographic class into Vs30 and construct a Vs30 map of Indonesia. This correlation was calibrated by using Vs data from BMKG (Indonesian Agency for Meteorological, Climatological, and Geophysics) as well as standard penetration test logs that were collected by the authors. Utilization of local field measurement data will certainly enhance the reliability of the Vs30 map. The developed nationwide Vs30 map will be very useful for disaster mitigation programs and for preliminary design of earthquake resistant buildings and infrastructure in Indonesia.

Real-Time Swing-up and Stabilization Control of a Cart-Pendulum System with Constrained Cart Movement

Abstract The cart-pendulum system is a typical benchmark problem in the control field. It is a fully underactuated system having one control input for two degrees-of-freedom (DOFs) system. It has highly nonlinear structure, which can be used to validate different nonlinear and linear controllers and has wide range of real-time (realistic) applications like rockets propeller, tank missile launcher, self-balancing robot, stabilization of ships, design of earthquake resistant buildings, etc. In this work, modeling, simulation and real-time control of a cart-pendulum system is performed. The mathematical model of the system is developed using Euler-Lagrange approach. In order to achieve a more realistic model, the actuator dynamics is considered in the mathematical model. The main aim of this work is to investigate the performance of two different control strategies- first to swing-up the pendulum to near unstable equilibrium region and second to stabilize the pendulum at unstable equilibrium point. The swing-up problem is addressed by using energy controller in which cart is accelerated by providing a force to the cart with a AC servo motor with the help of timing pulley arrangement. The initial velocity of the cart is taken into account to confirm swing-up in the restricted track length. The cart displacement in the restricted track length is verified by simulation and experimental test-run. The regulation problem of stabilization of pendulum is addressed by developing the controller using Pole Placement Controller (PPC) and LQR Controller (LQRC). Both the control strategies are performed analytically and experimentally using the Googoltech Linear Inverted Pendulum (GLIP) setup. The analytical results, simulated in MATLAB and SIMULINK environment, are found in close agreement with the experimental results. In order to demonstrate the effect of both the stabilizing controllers on the performance of the system, comparison of the experimental results is reported in this work. It is demonstrated experimentally that LQR controller outperforms the Pole Placement controller, in terms of reduction in the oscillations of the inverted pendulum (56 %), as well as the magnitude of maximum control input (66.7 %). Further, robustness of the closed-loop system is investigated by providing external disturbances.

Creativity of Junior High School’s Students in Designing Earthquake Resistant Buildings

This research was stimulated by the present the territory of Indonesia is largely an area prone to earthquakes and the issue that human resources and disaster response planning process is still less competent and not optimal. In addition, the construction of houses and public facilities has not been in accordance with earthquake-resistant building standards. This study aims to develop students’ creativity through earthquake resistant building model’s projects. The research method used is descriptive qualitative method. The sample is one of the 7th grades consisting of 32 students in one of the junior high schools, Indonesia. Data was collected using an observation sheets and student worksheet. Results showed that students’ creativity in designing earthquake resistant building models varies greatly and yields new solutions to solve problems.

Communicating Earthquake Preparedness: The Influence of Induced Mood, Perceived Risk, and Gain or Loss Frames on Homeowners' Attitudes Toward General Precautionary Measures for Earthquakes.

Despite global efforts to reduce seismic risk, actual preparedness levels remain universally low. Although earthquake-resistant building design is the most efficient way to decrease potential losses, its application is not a legal requirement across all earthquake-prone countries and even if, often not strictly enforced. Risk communication encouraging homeowners to take precautionary measures is therefore an important means to enhance a country's earthquake resilience. Our study illustrates that specific interactions of mood, perceived risk, and frame type significantly affect homeowners' attitudes toward general precautionary measures for earthquakes. The interdependencies of the variables mood, risk information, and frame type were tested in an experimental 2 × 2 × 2 design (N = 156). Only in combination and not on their own, these variables effectively influence attitudes toward general precautionary measures for earthquakes. The control variables gender, "trait anxiety" index, and alteration of perceived risk adjust the effect. Overall, the group with the strongest attitudes toward general precautionary actions for earthquakes are homeowners with induced negative mood who process high-risk information and gain-framed messages. However, the conditions comprising induced negative mood, low-risk information and loss-frame and induced positive mood, low-risk information and gain-framed messages both also significantly influence homeowners' attitudes toward general precautionary measures for earthquakes. These results mostly confirm previous findings in the field of health communication. For practitioners, our study emphasizes that carefully compiled communication measures are a powerful means to encourage precautionary attitudes among homeowners, especially for those with an elevated perceived risk.

Fundamental period of infilled RC frame structures with vertical irregularity

The determination of the fundamental period of vibration of a structure is essential to earthquake design. Current codes provide formulas for the approximate estimation of the fundamental period of earthquake-resistant building systems. These formulas are dependent only on the height of the structure or number of storeys without taking into account the presence of infill walls into the structure, despite the fact that infill walls increase the stiffness and mass of the structure leading to significant changes in the fundamental period. Furthermore, such a formulation is overly conservative and unable to account for structures with geometric irregularities. In this study, which comprises the companion paper of previous published research by the authors, the effect of the vertical geometric irregularities on the fundamental periods of masonry infilled structures has been investigated, through a large set of infilled frame structure cases. Based on these results, an attempt to quantify the reduction of the fundamental period due to the vertical geometric irregularities has been made through a proposal of properly reduction factor.

Lightweight concrete design using gene expression programing

The use of lightweight concrete (LWC) in earthquake resistant buildings is beneficial because of the weight and mass reduction of the structures. LWC has been used in the construction industry for many years and while attempts have been made to develop a practical and reliable code for lightweight concrete design worldwide a satisfactory, practical standard for mix design is required. There are a few standards which present methods for designing the mix of LWC such as ACI 211.2. However, in these standards the proposed compressive strength and density determinations cannot be used for all types of lightweight aggregates. The aim of this study is to provide references for three types of lightweight concretes containing clay and natural (mineral) pumice aggregates with the maximum nominal sizes of 12.7mm (½in.) and 19.2mm (¾in.) respectively. With this intent, hundred specimens of lightweight concrete were made and then tested in the laboratory using these aggregates. After presenting a standard for propositioning and adjusting propositions of the concrete mix three equations were derived using Gene Expression Programing (GEP) to obtain the compressive strength of a specific mixture. Comparison between the actual properties and their predicted counterparts indicated that the proposed derivations are a useful and reliable practical method for use by practicing engineers when designing lightweight concrete mixes.

The behaviour of reinforced concrete structure due to earthquake load using Time History analysis Method

Earthquakes are one of the most dangerous, destructive and unpredictable natural hazards, which can leave everything up to a few hundred kilometres in complete destruction in seconds. Indonesia has a unique position as an earthquake prone country. It is the place of the interaction for three tectonic plates, namely the Indo-Australian, Eurasian and Pacific plates. Banda Aceh is one of the cities that located in earthquake-prone areas. Due to the vulnerable conditions of Banda Aceh some efforts have been exerted to reduce these unfavourable conditions. Many aspects have been addressed, starting from community awareness up to engineering solutions. One of them is all buildings that build in the city should be designed as an earthquake resistant building. The objectives of this research are to observe the response of a reinforced concrete structure due to several types of earthquake load, and to see the performance of the structure after earthquake loads applied. After Tsunami in 2004 many building has been build, one of them is a hotel building located at simpang lima. The hotel is made of reinforced concrete with a height of 34.95 meters with a total area of 8872.5 m2 building. So far this building was the tallest building in Banda Aceh.

Buildings Stability Revaluation in Seismically Active Regions

In 2015 the maps of seismic zoning on the territory of Russia were detailed according to new general standards (ОSR-2015). Compared to the previous data, the number of seismically dangerous areas has the tendency to increase. Most buildings in those areas of the country were designed and constructed as less earthquake resistant. The physical and mechanical characteristics of the soil in the buildings foundation are being changed under the influence of different ecological, engineering, geological, and man-made factors. The latest research discovers the high level of soil influence on seismic resistance of buildings. Further detailed examination of earthquake resistance of buildings in the northern territories of Russia has been planned according to the changes and influences mentioned above in order to lower the earthquake risks.

PROSPECTS OF ESTABLISHING EARTHQUAKE RESISTANT BUILDINGS FROM TUBE CONCRETE CONSTRUCTIONS

Abstract. Objectives The aim of the research is to find optimal design solutions for the erection of buildings that will ensure their reliability and durability, compliance with environmental requirements, fire resistance and earthquake resistance. In this regard, the task is to determine the advantages and prospects of erecting earthquake resistant buildings from concrete constructions, since they are distinct in constructive, technological and economic efficiency when are used as vertical load-bearing struts of high-rise buildings. Method The technique for calculating the strength of normal sections of eccentrically-compressed concrete elements uses a nonlinear deformation model, taking into account the joint operation of the steel shell and the concrete core under the conditions of triaxial compression. Results In the article the review of the newest world experience of using concrete as vertical load-bearing structures for public facilities from the standpoint of earthquake resistant construction is given. The international practices of public facility construction ranging in height from 100 to 600 m with the use of concrete technology, including regions with dangerous natural and man-made conditions, have been studied. The structural, operational and technological advantages and disadvantages of concrete technology are analysed. Methods for calculating the strength of concrete elements in the case of central compression are considered: according to the so-called deformation theory, the state of total destruction of both concrete and fluidity attained at maximum pressure are indicated by the beginning of tube flow on the longitudinal axis. The advantages and disadvantages of both methods are shown. Factors constraining the introduction and wider application of concrete constructions in Russia are considered. Conclusion While the advantages of concrete constructions in their extensive implementation in earthquake-resistant construction are obvious, further in-depth studies of the behaviour of concrete elements operating under both static and dynamic stresses repeatedly, statically indeterminate load-carrying building frames are needed.

Evaluation of the seismic performance of special moment frames using incremental nonlinear dynamic analysis

In this paper, the incremental nonlinear dynamic analysis is used to evaluate the seismic performance of steel moment frame structures. To this purpose, three special moment frame structure with 5, 10 and 15 stories are designed according to the Iran\'s national building code for steel structures and the provisions for design of earthquake resistant buildings (2800 code). Incremental Nonlinear Analysis (IDA) is performed for 15 different ground motions, and responses of the structures are evaluated. For the immediate occupancy and the collapse prevention performance levels, the probability that seismic demand exceeds the seismic capacity of the structures is computed based on FEMA350. Also, fragility curves are plotted for three high-code damage levels using HASUS provisions. Based on the obtained results, it is evident that increase in the height of the frame structures reduces the reliability level. In addition, it is concluded that for the design earthquake the probability of exceeding average collapse prevention level is considerably larger than high and full collapse prevention levels.9.

Critical Review on Base Isolation: An Earthquake-Resistant Technique

Every structure is subjected to some sort of dynamic loading during its entire life span. Dynamic loading in structure systems may result from a wide variety of sources such as wind, waterways, earthquake, blasts and others. Earthquake forces are the most devastating one among dynamic loadings. A disruptive disturbance that causes collision of tectonic plates in Earth's crust and results in shaking of the earth surface is known as earthquake. These forces last only for a fraction of a minute but will often cause great loss of life and property. Therefore, it is time requirement to make earthquake-resistant buildings for providing safety to buildings. Consequently, attempts have been made to make earthquake-resistant structures all over the world. Base isolation is an effective method for improving the seismic performance of structures and to counteract the detrimental component of seismic forces. This method consists of secerning of building from horizontal ground motion by placing horizontally discrete isolators at the base level of structure. In this paper, the different types of base isolation systems and bearings used for base isolation technique are discussed.

Plastic design of eccentrically braced frames with shear panels

This paper introduces a new earthquake-resistant building design featuring eccentrically braced frames with steel wall shear panels. It also proposes closed-form expressions for analysis and extension of the existing failure mode control design method for the new structural system. Closed-form equations for internal forces were obtained, and probable failure mechanisms and corresponding lateral load multipliers for secondary effects were identified. Selection of member profiles was completed by the mechanism equilibrium curve concept. Pushover modelling was then performed with plastic hinge distribution corresponding to failure mechanisms. Only small differences were found between the analytical and modelled values of lateral force multipliers, meaning that the closed-form equations are a valid alternative approach for plastic analysis and design of eccentrically braced frames with shear panels.

Retrofitting in the Middle of Project Execution: Case Study of a Public Hospital Building

Since the publication of the Conseil International du Bâtiment or CIB's Agenda 21, local government has become an agent of change to achieve sustainability in development policy-making, including implementation of building standards. The Indonesian Earthquake-Resistant Building Standard was recently revised after considering sustainability and earthquake damage reduction methods by drawing on lessons learnt from past earthquakes. However, the willingness of building practitioners and local authorities to deal with those changes, particularly on the budget implications of project execution and appropriate procurement mechanisms, has raised a number of issues. Several of these stem from the lack of awareness and consistency in educating practitioners and officials. As a consequence, the implementation of the new standard has been slow and problematic. This paper presents a case study the impact of implementing and retrofitting a new earthquake resistance standard in a public hospital building in the middle of project execution. The research undertook structural simulation and field observation on an eight-storey public hospital building in Indonesia. The research found that the capabilities of contractors and awareness of local authorities of dynamical changes of policy implementation affected the project success. The analysis suggests that empirical guidance by the local authority is required for practical adjustments in governing retrofitting procedures in public building management.

Advancing integrated STEM learning through engineering design: Sixth-grade students’ design and construction of earthquake resistant buildings

ABSTRACTAs part of a 3-year longitudinal study, 136 sixth-grade students completed an engineering-based problem on earthquakes involving integrated STEM learning. Students employed engineering design processes and STEM disciplinary knowledge to plan, sketch, then construct a building designed to withstand earthquake damage, taking into account a number of constraints. On testing, students redesigned to build an improved structure. Using a framework of design processes, we report on the students' capabilities in planning, creating annotated sketches, and transforming these into 3D models. An understanding of core STEM concepts was apparent in their responses, including shape properties, stability, rigidity, balance, strength, and engineering techniques. Group problem solving involved moving iteratively between design phases, frequently revisiting problem scoping, being cognizant of the problem goal, boundaries and constraints, and appreciating design sketches as guiding constructions. Students were also observed to consider a number of problem components simultaneously, indicating their capabilities in handling the complexity of the task.

Prediction of lightweight aggregate concrete compressive strength using ultrasonic pulse velocity test through gene expression programming

The use of lightweight structural concreteto reduce the weight of earthquake resistant buildings is very useful, and utilizing non-destructive tests for determining the concrete strength of these structures is essential.Ultrasonic pulse velocity test is one of the main methods of non-destructive testing in the assessment of compressive strength of concrete in the service area. The aim of this study is estimation of the compressive strength of lightweight aggregate concreteby offering suitable mathematical formulations.For this purpose, many samples of three different types of lightweight aggregate concrete are made and tested by concrete breaking machine and Ultrasonic pulse velocity instrument.Then some relationships for prediction of the compressive strength of the concrete by using ultrasonic test results are presented. Two different methods of fitting exponential function and Gene Expression Programming (GEP) are utilized to find the proper relationships. The results show that the exponential function has high accuracy in estimating the compressive strength of lightweight aggregate concrete made ​​with natural pumices. But it doesn’t have good results for concrete made of expanded clay. However the GEP has high accuracy for all the materials and the experimental results are perfectly compatible with the test results.

On the Filtering Properties of Foundations of Earthquake-Resistant Buildings

The results of full-scale experiment (M. D. Trifunak, S. S. Ivanovich, M. I. Todorovska, E. I. Novikova, and A. A. Gladkov, Soil Dynamics and Earthquake Engineering, 18, No. 3, 169–187 (1999)) are discussed. The actual wave pattern in foundation bed of a sevenstory building that shows the nonuniformity of the soil properties and the displacement of the center of stiffness of the foundation, resulting in appreciable torsional oscillations, was obtained in the course of the experiment. Analysis of the experimental results will be helpful in the calculation of the earthquake-resistance of the foundations and foundation beds and monitoring their state after strong earthquakes.

Free Vibration Analysis of Multi-Storeyed Buildings resting on different Soil / Rock Media at Hyderabad, Telangana State, India

Earthquake is a spasm of ground shaking caused due to sudden release of energy in the earth’s crust and bulk of destruction takes place within a short duration of time. Past history records reveal that rate of occurrence of earthquakes is an increasing phenomena. Bitter experiences on failure/collapse of structures, particularly in urban regions, warn the people on importance of constructing earthquake resistant buildings. Local soil conditions and interaction between soil /rock media and the structure indeed affect the response of the structure during an earthquake. In the present investigation, the western region of Hyderabad, part of the capital of Telangana, is chosen as the study area which consists of different soil/rock profiles at different locations. Free vibration analysis of a multi-storeyed building is carried out when the foundation of similar structure rests on different soil/rock media. Frequencies and time periods are worked out for comparison when the same structure is assumed to be fixed at the base. From the results, it is observed that the variation in time period of the structure increases with decrease of soil stiffness. It is also noticed that soil-structure interaction effect on time period of the structure, particularly in loose soils, is of more significant compared to the variation in structure stiffness.

Investigated Solution of Urban Problems in Turkey Example of Fikirtepe Urban Transformation Project

This study shows a sample of shanty houses from Turkey and gives details about most famous squatting area. This study also provides insight about Fikirtepe, about its total area, most important problems as a squatting area, and actions on target and solution alternatives to be offered. The Main objective of this article is to browse the existing problems of Fikirtepe to understand the basic problems of slums in Turkey. All informations were gathered from authorized and reliable persons at state institutions. Fikirtepe area was visited and all projects were observed closely to evaluate gathered information. Squatting fact was started at very early years as other big cities of Turkey and stepped up after industrial revolution. Due to location of Fikirtepe, it has been one of the best places to settle for many migrants and this caused high increase of population. As a result, all insufficient services became useless. On the other hand, all illegal shanty houses, which were built without any plan, were threaten for local people. Especially the fault line that takes place under the area increases the level of threat significantly. Based on these facts, transforming Fikirtepe to a modern neighborhood with earthquake resistant buildings was carried into effect by authorized corporations. Major problem at neighborhood is wrong usage of land. Subject problem created domestic migration movement. Most probably, the wrong usage of land is the main reason for illegal settlement of migrants to area by ignoring range basic services. It causes lack of services