Engineering Assessment of Earthquake Resistant Building Code Based on Seismic Load Responses

In the realm of structural design, Seismic Analysis is crucial. Many structures have collapsed because of earthquakes; as a result of numerous studies, different methods for analysing and determining vibration modes of a structure have been created. Seismic analysis can be done in two ways: static analysis and dynamic analysis. The basic mode of vibration dominates the response in the static technique of seismic analysis, and the mass and stiffness of the structures are evenly distributed, resulting in a regular shape, however this assumption fails for irregular buildings. As a result, dynamic methods are used to solve this issue. Response spectrum is one such dynamic method that is relatively simple to utilize compared to others. The benefit of employing the seismic response spectrum method is that it aids in the prediction of displacement and member forces in structural systems. As a result, this method aids in determining peak structural responses within a linear range, which can then be used to calculate lateral forces created in structures due to earthquakes, allowing for more earthquake-resistant building design. Although this method is approximate, it is a cost-effective and beneficial method for preliminary design research. The response spectrum method is used on STAAD.PRO V8i software to design a G+4 residential structure in our study. The building’s measurements are 16 meters long, 12 meters wide and 15 meters tall. The foundation was built to a depth of 1.5 meters. The structure was built to withstand earthquakes in seismic zone III on medium-density soil. Dead load (IS 875 Part I), Live load (IS 875 Part II), Seismic Load (IS 1893 Part I), and Wind Load are some of the load instances that were presented based on Indian Standard code (IS 875 Part III). To acquire the best response, the response spectrum modal combination Complete Quadratic Combination (CQC) is used. Various parameters like wind intensity, seismic parameters, dynamic weight, modal participation factors, base shear and peak storey shear are calculated. Base shear and peak storey shear are found to maximum in Mode 2 and between 5th and 6th respectively.

Artificial intelligence and its sub-branch, machine learning technologies, have developed rapidly in recent years and their use for various purposes has seemed to be increased in various sectors from automotive to medicine, from law to marketing. Similarly, these technologies have begun to be used in the building sector and in the field of architecture. These technologies are being used in many fields in architecture such as feasibility studies, building design, project control, occupational safety, earthquake resistant building design and applications, energy efficient system design, construction with smart construction equipment, smart building design, and smart facade design. Despite this increasing use in the field, it has been determined by the literature review that the number of studies focusing on the use of machine learning in architecture, especially on building facades, is low. In this sense in the study, it is aimed to examine the relationship between artificial intelligence and machine learning technologies with architecture in the context of building facades. Initially in the study the topics and the historical process related to artificial intelligence and machine learning were explained, subsequently the use of technologies on the building facades was examined through examples. In this way, a guiding resource has been created for those who want to work on this subject in the future.

While the earthquake resistant building design and construction code has been developed in sophisticated national/city level, the implementation at the local level has been more of an exception than the rule. Other than concrete and steel, one such material that can be used in construction in the seismic zone area of the developing countries like India, especially in the northeast states, is bamboo, where bamboo is available in abundant. Bamboo’s light weight and relative flexibility make it a particularly attractive alternative for residential construction in seismic regions. Compared on a mass-per-volume basis to concrete, steel and wood, bamboo is second to concrete for strength, and ranks first for stiffness. As strong as mild steel with the compression strength of concrete, amazingly, one inch of bamboo can hold up to 7 1/2 tons of weight. This present study is an attempt to implement bamboo construction in Manipur which is regarded as one of the most seismically active regions worldwide. In this work, a bamboo housing system and a reinforced concrete frame structural system was modeled using finite element analysis program SAP, considering the model structures to be taken from the types of building that is built in Manipur. A parametric study is conducted to investigate the seismic performance of the structures and El-Centro Earthquake and Kobe Earthquake recorded excitation are used for input in the dynamic analysis on the models. The study has revealed that the bamboo structures are performing better in earthquake than the commonly built RC residential building. The behavior of the bamboo structure modeled in this present study gives an opportunity to accept bamboo as a construction material in seismic zone areas.

Non structural elements in a building are those members which come in to the path of earthquake force affected by it but do not take part in the dissipation of energy produced during an earthquake. Failure of these members during an earthquake causes not only economic losses but human life too. The building will remain safe after an earthquake but may become unserviceable for the purpose for which it has been constructed. For the earthquake resistant design of building study of behavior of these members is necessary. It has been found that seismic design of structure is given much attention but very little attention has been given to protecting non structural member of the buildings 1 . This article has been prepared after studying codes and articles published in various journals. The main objective of this article is to make design people aware of the importance of non structural element in the earthquake resistant design of buildings.

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.

In this study, it is aimed to investigate the effect of different soil classes on the behavior of the structure under earthquake loads. An evaluation was made for five-storey and eight-story reinforced concrete (RC) frame structures considering the three different soil classes (ZC, ZD, ZE) defined in the Turkish Building Earthquake Code 2018 (TBEC 2018) and the current earthquake hazard of Sakarya. In the structural system of the RC frame, the cross-section geometry and reinforcement details of the columns and beams were designed by considering the design criteria in TBEC 2018. While determining the dynamic behavior of the structure, the effective bending rigidity defined for column and beam elements in TBEC 2018 was used. For the RC frame structural model, the base shear force, story displacements and story drifts were investigated comparatively by using the mode superposition method in the SAP2000 finite element analysis program. When the results are compared, it is seen that as the soil stiffness decreases, the force and displacement demands on the structure increase.

Response of a building structure due to sloshing effect in an overhead water tank

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.

Structural control through energy dissipation systems has been increasingly implemented internationally in recent years and has proven to be a most promising strategy for the earthquake safety of structures. In extending the “classical” approach of the capacity design for earthquake structural resistance, the integration of passive damping devices within the structure aims at energy dissipation within specific structural zones. The present paper examines an alternative control system for achieving dynamic structural adaptability, which consists of an energy dissipation device and a cable bracing mechanism with a kinetic closed circuit, working only in tension. The closed bracing mechanism does not practically affect the initial stiffness of the system, i.e. the concept relies on two completely “separate” systems: a primary for the verticaland wind loads and a secondary for the earthquake loads. An additional feature of the bracingdamper mechanism compared to conventionally passively controlled systems is the contribution of all bracing members to the energy dissipation during a loading cycle. Three “dual systems” with different configurations of the closed bracing mechanisms and damping devices are investigated in their dynamic behaviour, in the time-history range under actual earthquakes of the GreekMediterranean region. The study provides significant response comparisons of the dual systems, in respect to the stiffness of the hysteretic dampers, its effect on the base shear force and the maximum relative displacements of the systems and to the energy dissipation behaviour of the bracing-damper mechanism.

The development of architectural design has increased numerous types of irregularities in structures, one of them is a T-shape building. The asymmetrical plan structure can induce a more unstable response due to earthquake loads. Buildings are generally designed using a rigid diaphragm rather than a semi rigid and flexible diaphragm. This study aimed to analyze the effects of diaphragm flexibility on structural response such as natural period, deformation, and base shear forces. The gravity and seismic loads on the buildings were based on SNI 1727:2013 and SNI 1726:2019. The finite element software program was used for modeling and running the analysis of structure. The results reveal that the rigid diaphragm structure has higher stiffness and generates smaller story displacement and base shear force than semi rigid and flexible diaphragm structures. The flexibility on irregular structure also affects the structural mode shape significantly.

Most seismic codes specify empirical formulas to obtain the fundamental period of buildings. The equations specified in present IS codes, are according to the available data on the time period of buildings measured from their recorded accelerograms. Shear-wall dominant reinforced concrete buildings, constructed, using codes specification are commonly built in different countries, facing a substantial seismic risk, in spite of their high resistance against ground motions. Current seismic code provisions including the Uniform Building Code (International Conference of Building Officials, Whittier, CA, 1997) and the Indian Seismic Code (Criteria for earthquake resistant design of buildings, fifth revision, 2002) are considered to evaluate the effect of time period on seismic behavior of building.In this study, time period obtained by code formulas are compared with those obtained by modal analysis in SAP2000. Also the top story displacement (as an adequate parameter of determination the seismic performance of building) correspond to the values of mentioned time period are estimated using uniform building code and software respectively. It is observed that current empirical equation for calculating the time period of RCC buildings is rather inaccurate. Also it is shown that the time period has very effective influence on seismic performance of building.

The inelastic behaviour of eccentric single‐storey building structures subjected to sinusoidal ground excitation is examined. The Kryloff‐Bogoliuboff method is employed to provide approximate solutions in the amplitude‐frequency domain. Structural resisting elements are assumed to exhibit bilinear hysteretic behaviour and coupled response is investigated in terms of both system response as well as individual element ductility requirements. In addition to demonstrating the well‐known softening property inherent in yielding systems, the importance of the principal parameters governing coupled response is evaluated in a consistent parametric fashion. Within the context of earthquake resistant building design, the results indicate the absence of amplified response when torsional and translational frequencies are close, in contrast to the much emphasized observation of internal resonance for linear elastic structures. Equally important, structural elements located on the stiff edge of eccentric buildings are found to be only marginally affected by the magnitude of the eccentricity, thus indicating that seismic building codes which reduce design requirements for these elements underestimate actual behaviour substantially.

Seismic design and inelastic seismic response of lumped mass mdof dual structure

Introducing important concepts in the study of earthquakes related to retrofitting of structures to be made earthquake resistant. The book investigates the pounding effects on base-isolated buildings, the soil-structure-interaction effects on adjacent buildings due to the impact, the seismic protection of adjacent buildings and the mitigation of earthquakeinduced vibrations of two adjacent structures. These concepts call for a new understanding of controlled systems with passive-active dampers and semi-active dampers. The passive control strategy of coupled buildings is investigated for seismic protection in comparison to active and semi-active control strategies.

In this study, a new type of seismic energy-dissipative device in the form of braces based on pre-bent strips has been utilized. In this approach, moment-resistance frame systems have been used for 3, 5, 7, 9, 11 and 12 stories and various models. The height of stories and all span lengths are 3 m. In order to compare the response of models, braced (with damper) and unbraced (without damper) have been modeled. Pre-bent steel strips have been used in braced frames. A bilinear strain-stress model of mild steel has been used in this simulation. The responses of structures with dampers and without dampers under dynamic loading have been compared. The results show that seismic responses, such as base shear, story acceleration and story velocity of 3, 5, 7, 9, 11 and 12 story frames with dampers have been improved (reduced) and these reductions have been decreased from 3 story frames to 12 story frames. This damper reduces the displacement of models on upper stories. A series of time history inelastic dynamic analyses have been conducted and the results show the feasibility and effectiveness of using the utilized devices as seismic dampers to reduce structural responses, such as base shear, acceleration, velocity and displacement of stories. This new kind of dissipative device controls seismic damage and reduces story responses under cyclic loading. Key words: Pre-bent strips, response of structure, damper, energy dissipation.