Download or read book Three dimensional Seismic Analysis of Reinforced Concrete Wall Buildings at Near fault Sites written by Yuan Jie Lu and published by . This book was released on 2014 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation approaches the subject of three-dimensional (3D) seismic analysis of reinforced concrete (RC) wall buildings at near-fault sites by first studying two main problems separately: (1) the characterization of base excitation for buildings located at near-fault sites, and (2) modeling the behavior of RC buildings accurately including inelastic behavior and the failure mode. The dissertation culminates with the 3D response history analysis of two 20-story RC core wall buildings models, including the slabs and columns, subject to a strong near-fault ground motion record. First, the presence and characteristics of multiple pulses [with dominant period TP between 0.5 and 12 s] in historical near-fault ground motion records is studied. An iterative method for extracting multiple strong pulses imbedded in a ground motion is presented. The method is used to extract multiple strong velocity pulses from the fault-normal horizontal component of 40 pulse-like ground motion records from 17 historical earthquakes, with magnitudes ranging from MW6.3 to MW7.9, recorded at a distance less than 10 km from the fault rupture with a peak ground velocity greater than 0.6 m / s. The relationships between the dominant period of the extracted pulses, associated amplitudes, and earthquake magnitude are presented, indicating that the amplitude of the strongest pulses with 1.5 s ≤ TP ≤ 5 s, does not depend significantly on the earthquake magnitude. Next, the effect of soil-foundation-structure interaction (SFSI) for a 20-story core wall building with a caisson foundation subject to single pulse motions is investigated using two-dimensional (2D) nonlinear finite-elements and fiber beam-column elements; nonlinear site effects on the free-field motion and structural response is discussed. The nonlinear site effects for free-field motions result in a de-amplification of peak surface acceleration due to soil yielding, and a maximum of 64% amplification of peak acceleration and velocity of at specific pulse periods for deep soils. SFSI, after removing the nonlinear site effect, has a negligible effect on the maximum value of peak roof acceleration and peak roof drift ratio over the pulse periods considered; however, the effect of the increased flexibility due to SFSI is observed in the peak drift ratio and peak base shear response. A couple of chapters of this dissertation are dedicated to the development and verification of a three-dimensional nonlinear cyclic modelling method for non-planar reinforced concrete walls and slabs. This modeling approached - called the beam-truss model (BTM) - consists of (i) nonlinear Euler-Bernoulli fiber-section beam elements representing the steel and concrete in the vertical and horizontal direction, and (ii) nonlinear trusses representing the concrete in the diagonal directions. The model represents the effects of flexure-shear interaction (FSI) by computing the stress and strains in the horizontal and vertical directions and by considering biaxial effects on the behavior of concrete diagonals. In addition, the BTM explicitly models diagonal compression and tension failures (shear failures) under cyclic or dynamic loading. The BTM is first validated by comparing the experimentally measured and numerically computed response of eight RC walls subjected to static cyclic loading, including two non-planar RC walls under biaxial cyclic loading. Then, the BTM is extended to modeling slabs and validated with a two-bay slab-column specimen. Finally, the BTM is validated by comparing the experimentally measured and numerically computed response and failure mode of a 5-story coupled wall RC building under seismic base excitation. The final chapter presents the 3D response history analysis of two 20-story RC core wall buildings subject to a strong near-fault ground motion record. The 20-story building model includes the RC core wall, post-tensioned slabs, and columns; the core wall and slabs are modeled using the developed BTM while the columns are modeled with fiber-section beam-column elements. The two 20-story RC core wall buildings considered have similar geometry: one is conventionally designed to develop plastic hinging at the base of the core-wall, and the second is designed with a damage resistant structural system that combines two seismic isolation planes. Analysis is conducted using the two horizontal components of the historical TCU52 ground motion recorded 0.7 km from the fault plane of the MW7.6 1999 Chi-chi, Taiwan earthquake. The seismic response and damage of the two buildings is discussed.

Download or read book Earthquake Resilient Tall Reinforced Concrete Buildings at Near Fault Sites Using Base Isolation and Rocking Core Walls written by Vladimir Calugaru and published by . This book was released on 2013 with total page 113 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation pursues three main objectives: (1) to investigate the seismic response of tall reinforced concrete core wall buildings, designed following current building codes, subjected to pulse type near-fault ground motion, with special focus on the relation between the characteristics of the ground motion and the higher-modes of response; (2) to determine the characteristics of a base isolation system that results in nominally elastic response of the superstructure of a tall reinforced concrete core wall building at the maximum considered earthquake level of shaking; and (3) to demonstrate that the seismic performance, cost, and constructability of a base-isolated tall reinforced concrete core wall building can be significantly improved by incorporating a rocking core-wall in the design. First, this dissertation investigates the seismic response of tall cantilever wall buildings subjected to pulse type ground motion, with special focus on the relation between the characteristics of ground motion and the higher-modes of response. Buildings 10, 20, and 40 stories high were designed such that inelastic deformation was concentrated at a single flexural plastic hinge at their base. Using nonlinear response history analysis, the buildings were subjected to near-fault seismic ground motions as well as simple close-form pulses, which represented distinct pulses within the ground motions. Euler-Bernoulli beam models with lumped mass and lumped plasticity were used to model the buildings. The response of the buildings to the close-form pulses fairly matched that of the near-fault records. Subsequently, a parametric study was conducted for the buildings subjected to three types of close-form pulses with a broad range of periods and amplitudes. The results of the parametric study demonstrate the importance of the ratio of the fundamental period of the structure to the period of the pulse to the excitation of higher modes. The study shows that if the modal response spectrum analysis approach is used--considering the first four modes with a uniform yield reduction factor for all modes and with the square root of sum of squares modal combination rule--it significantly underestimates bending moment and shear force responses. A response spectrum analysis method that uses different yield reduction factors for the first and the higher modes is presented. Next, this dissertation investigates numerically the seismic response of six seismically base-isolated (BI) 20-story reinforced concrete buildings and compares their response to that of a fixed-base (FB) building with a similar structural system above ground. Located in Berkeley, California, 2 km from the Hayward fault, the buildings are designed with a core wall that provides most of the lateral force resistance above ground. For the BI buildings, the following are investigated: two isolation systems (both implemented below a three-story basement), isolation periods equal to 4, 5, and 6 s, and two levels of flexural strength of the wall. The first isolation system combines tension-resistant friction pendulum bearings and nonlinear fluid viscous dampers (NFVDs); the second combines low-friction tension-resistant cross-linear bearings, lead-rubber bearings, and NFVDs. The designs of all buildings satisfy ASCE 7-10 requirements, except that one component of horizontal excitation is used in the two-dimensional nonlinear response history analysis. Analysis is performed for a set of ground motions scaled to the design earthquake (DE) and to the maximum considered earthquake (MCE). At both the DE and the MCE, the FB building develops large inelastic deformations and shear forces in the wall and large floor accelerations. At the MCE, four of the BI buildings experience nominally elastic response of the wall, with floor accelerations and shear forces being 0.25 to 0.55 times those experienced by the FB building. The response of the FB and four of the BI buildings to four unscaled historical pulse-like near-fault ground motions is also studied. Finally, this dissertation investigates the seismic response of four 20-story buildings hypothetically located in the San Francisco Bay Area, 0.5 km from the San Andreas fault. One of the four studied buildings is fixed-base (FB), two are base-isolated (BI), and one uses a combination of base isolation and a rocking core wall (BIRW). Above the ground level, a reinforced concrete core wall provides the majority of the lateral force resistance in all four buildings. The FB and BI buildings satisfy requirements of ASCE 7-10. The BI and BIRW buildings use the same isolation system, which combines tension-resistant friction pendulum bearings and nonlinear fluid viscous dampers. The rocking core-wall includes post-tensioning steel, buckling-restrained devices, and at its base is encased in a steel shell to maximize confinement of the concrete core. The total amount of longitudinal steel in the wall of the BIRW building is 0.71 to 0.87 times that used in the BI buildings. Response history two-dimensional analysis is performed, including the vertical components of excitation, for a set of ground motions scaled to the design earthquake and to the maximum considered earthquake (MCE). While the FB building at MCE level of shaking develops inelastic deformations and shear stresses in the wall that may correspond to irreparable damage, the BI and the BIRW buildings experience nominally elastic response of the wall, with floor accelerations and shear forces which are 0.36 to 0.55 times those experienced by the FB building. The response of the four buildings to two historical and two simulated near-fault ground motions is also studied, demonstrating that the BIRW building has the largest deformation capacity at the onset of structural damage.

Download or read book Inelastic Three dimensional Response Analysis of Reinforced Concrete Building Structures IDARC 3D written by Sashi K. Kunnath and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonlinear Seismic Analysis and Design of Reinforced Concrete Buildings written by P. Fajfar and published by CRC Press. This book was released on 1992-03-20 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forty scientists working in 13 different countries detail in this work the most recent advances in seismic design and performance assessment of reinforced concrete buildings. It is a valuable contribution in the mitigation of natural disasters.

Download or read book Seismic Performance of Concrete Buildings written by Liviu Crainic and published by CRC Press. This book was released on 2012-12-10 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines and presents essential aspects of the behavior, analysis, design and detailing of reinforced concrete buildings subjected to strong seismic activity. Seismic design is an extremely complex problem that has seen spectacular development in the last decades. The present volume tries to show how the principles and methods of earthquake engineering can be applied to seismic analysis and design of reinforced concrete buildings. The book starts with an up-to-date presentation of fundamental aspects of reinforced concrete behavior quantified through constitutive laws for monotonic and hysteretic loading. Basic concepts of post-elastic analysis like plastic hinge, plastic length, fiber models, and stable and unstable hysteretic behaviour are, accordingly, defined and commented upon. For a deeper understanding of seismic design philosophy and of static and dynamic post-elastic analysis, seismic behavior of different types of reinforced concrete structures (frames, walls) is examined in detail. Next, up-to-date methods for analysis and design are presented. The powerful concept of structural system is defined and systematically used to explain the response to seismic activity, as well as the procedures for analysis and detailing of common building structures. Several case studies are presented. The book is not code-oriented. The structural design codes are subject to constant reevaluation and updating. Rather than presenting code provisions, this book offers a coherent system of notions, concepts and methods, which facilitate understanding and application of any design code. The content of this book is based mainly on the authors’ personal experience which is a combination of their teaching and research activity as well as their work in the private sector as structural designers. The work will serve to help students and researchers, as well as structural designers to better understand the fundamental aspects of behavior and analysis of reinforced concrete structures and accordingly to gain knowledge that will ensure a sound design of buildings.

Download or read book Seismic Performance and Modeling of Reinforced Concrete and Post Tensioned Precast Concrete Shear Walls written by Ahmet Can Tanyeri and published by . This book was released on 2014 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Past earthquakes have shown examples of unsatisfactory performance of buildings using reinforced concrete structural walls as the primary lateral-force-resisting system. In the 1994 Northridge earthquake, examples can be found where walls possessed too much overstrength, leading to unintended failure of collectors and floor systems, including precast and post-tensioned construction. In the 2010 Maule Chile earthquake, many structural wall buildings sustained severe damage. Although Chilean design standards result in different reinforcement detailing than is common in U.S. walls, the failure patterns raise concerns about how well conventionally reinforced structural walls in U.S. buildings will perform during the next earthquake. Alternative wall design philosophies that offer more predictable response, with better damage control, should be investigated. After the Mw 8.8 Chile earthquake, the 15-story Alto Rio building in Concepción sustained failures near the base, overturned, and came to rest on its side. The collapse of the Alto Rio building was significant because it was designed using the Chilean Building Code NCh433. Of96, which requires the use of ACI 318-95 for design of reinforced concrete structural elements intended to resist design seismic forces. The failure of the Alto Rio building is significant for many reasons. It is the first modern shear wall building of its type to collapse by overturning during an earthquake. The building is studied using forensic data and structural models of the framing system subjected to earthquake shaking. The study identifies the likely failure mechanism and suggests areas for which design and detailing practices could be improved. The capabilities and shortcomings of the analyses to identify details of the failure mechanism are themselves important outcomes of the study. A second study explores the behavior of structural wall buildings using unbonded post-tensioned structural walls. Such walls offer the opportunity to better control yielding mechanisms and promote self-centering behavior. The study focuses on the measured responses of a full-scale, four-story building model tested on the E-Defense shaking table in Japan. The seismic force-resisting system of the test building comprised two post-tensioned (PT) precast frames in one direction and two unbonded PT precast walls in the other direction. The building was designed using the latest code requirements and design recommendations available both in Japan and the U.S., including the ACI ITG-5.2-09. The test building was subjected to several earthquake ground motions, ranging from serviceability level to near collapse. Analytical studies were carried out to test the capability of the structural models to replicate behaviors important to structural engineers, and to assess whether available analysis tools are sufficient to model dynamic behavior that results when a full-scale building is subjected to realistic earthquake ground shaking. Measured response data from such an outstanding test provides an opportunity to fully understand the response characteristics of PT walls and assess the ability of nonlinear analytical models to reproduce important global and local responses, including three-dimensional system interactions, both prior to and after loss of significant lateral strength. Moreover, this study to assess behavior and system interaction of PT walls leads to improvements of the current design ideas and performance expectations. The present study examines both the collapse of the Alto Rio building in Chile and the shaking table tests of the unbonded post-tensioned wall building in Japan. The collapse study suggests areas of improvement in current design and detailing practice. The shaking table study suggests an alternative approach to design of shear walls in buildings. Both studies demonstrate the use of modern structural analysis tools to interpret building responses to earthquake shaking. Taken together, the studies provide added confidence in earthquake simulation capabilities and demonstrate alternatives for designing earthquake-resistant buildings that use structural walls.

Download or read book Seismic Design for Buildings written by United States. Department of Defense. Tri-Service Seismic Design Committee and published by . This book was released on 1973 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Design Aids for Nonlinear Analysis of Reinforced Concrete Structures written by Srinivasan Chandrasekaran and published by CRC Press. This book was released on 2016-04-19 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tools to Safeguard New Buildings and Assess Existing OnesNonlinear analysis methods such as static pushover are globally considered a reliable tool for seismic and structural assessment. But the accuracy of seismic capacity estimates-which can prevent catastrophic loss of life and astronomical damage repair costs-depends on the use of the correct b

Download or read book Static and Earthquake Analysis of Three dimensional Frame and Shear Wall Buildings written by Edward L. Wilson and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Analysis and Evaluation of a Building Retrofitted with New RC Walls written by Seda Mursel and published by . This book was released on 2021 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents a study on the seismic performance of a retrofitted concrete building in Mexico City. The original lateral force resisting system consisted of reinforced concrete (RC) columns supporting waffle slabs along with RC walls located in the elevator core. After having suffered damages during an earthquake in 2017, the building was retrofitted by adding new RC shear walls. The structural response of the retrofitted building was evaluated using nonlinear analytical models. The response and performance of the newly-added RC wall components were studied employing nonlinear truss models and strain-based acceptance criteria. The results of the wall evaluations were compared with those obtained using the ASCE/SEI 41-17 methodology, which involves backbone moment-rotation relations and rotation limits for the plastic hinges of flexure-dominated walls. The results of the truss models were used to adjust the calibration of hinge models for each of the wall components. A three-dimensional nonlinear model of the entire building was developed employing nonlinear frame elements with plastic hinges for the walls. Two different calibrations of the hinge models were considered: the ASCE/SEI 41-17 moment-rotation curves and the adjusted curves derived from nonlinear truss models. The performance of the retrofitted building was, thereafter, evaluated using nonlinear static analysis, and the results obtained with the two hinge calibrations were compared

Download or read book Inelastic Three dimensional Response Analysis of Reinforced Concrete Building Structures IDARC 3D written by Sashi K. Kunnath and published by . This book was released on 1989 with total page 135 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic design of reinforced concrete structures for controlled inelastic response design concepts written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 1997-03-01 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Seismic Design Testing and Analysis of Reinforced Concrete Wall Buildings written by Marios Panagiotou and published by . This book was released on 2008 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large investments have recently been made for the construction of new medium- and high-rise buildings in California. In many cases performance-based designs have been the preferred method for these buildings. A main consideration in performance-based seismic design is the estimation of the likely development of structural and nonstructural damage limit-states given a hazard level. For this type of buildings efficient modeling techniques are required able to compute the response at different performance states. A research work was conducted at University of California San Diego (UCSD) on the i) seismic design, ii) experimental response and iii) computational modeling of medium- and high-rise reinforced concrete wall buildings. In the first part of this work a displacement-based seismic design method for use within performance-based is developed. Capacity design is used to control the mechanism of inelastic deformation. Based on principles of plastic analysis and structural dynamics the new formulation allows the computation of the effects of system overstrength and of the higher modes of response. Equal emphasis is given to displacement, force and acceleration demand parameters. The ground motion destructiveness potential is also determined. Application of the method to reinforced concrete wall buildings is discussed. The method is validated with the experimental response of a full-scale 7 story building. In addition a dual plastic hinge design concept for improving the performance and optimizing the construction of high-rise buildings is presented. The second part presents the experimental research program, with extensive shake table tests, of a full-scale 7-story reinforced concrete wall building slice, that was conducted at UCSD. The base shear coefficient obtained by the proposed method, of the first part of the research work, described above was 50% of that required by the equivalent static method prescribed by the ASCE-7 code. In spite of the reduced amount of longitudinal reinforcing steel, all performance objectives were met. The response of the building was significantly influenced, as expected, by the interaction of the main lateral force resisting wall with other structural elements (kinematic overstrength) and by the higher modes of response. Finally the third part presents a dynamic nonlinear strut-and-tie modeling approach developed for the analysis and evaluation of damage limit-states in reinforced concrete walls. The modeling approach is verified with the response of the UCSD 7-story building test.

Download or read book A study on seismic response of reinforced structures retrofitted with fluid viscous dampers in shear walls written by Sachin Kuckian and published by GRIN Verlag. This book was released on 2019-08-05 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: Master's Thesis from the year 2015 in the subject Engineering - Geotechnology, grade: 9.44, , course: Masters (Structural Engineering), language: English, abstract: The present study investigates the seismic behavior of multi-story building using damping devices strategically located within the lateral load resisting elements. It concentrates on a retrofitting strategy with passive energy dissipation device known as Fluid Viscous Damper (FVD) which will be applicable to new design as well as retrofitting existing buildings to ensure seismic safety by fitting damping devices which can transform a wall panel into a damping element. The first study involves analysis of a nine-story model having cut-outs and the use of the dampers of different configuration in these structures. The second study involves the use the diagonal brace configuration dampers provided in the cutout sections of 2D 9, 18, 27 storey structures and 3D 27 storey with core wall structure at three consecutive story levels each. For the second study, the cut out locations is varied depending on their relative positions. The relative position is the ratio of the total height of the structure to the upper edge of the topmost cut-out. These structures were initially modeled and time history analysis was performed on the structure without FVD and the structure retrofitted with FVD. Three different ground motions were used for the analysis. Results of the un- retrofitted structures are then compared with a retrofitted structure in terms of peak story displacements, roof accelerations, and pseudo-spectral accelerations. Study shows that there has been a significant reduction in seismic demands for a structure retrofitted with FVD in terms of peak storey displacements, pseudo-spectral accelerations and roof accelerations when the dampers are placed at lower three cut outs i.e. with high relative position. It is also observed that damping coefficient value obtained is least for upper toggle-brace configuration out of the four different damper configurations and with maximum reduction compared to other configurations. For modeling and analysis purpose the software SAP2000® is used. Through the study it could be concluded that FVD significantly reduces the seismic demands of the structure in terms of peak storey displacements, pseudo-spectral accelerations and roof accelerations. This suggests that FVDs can be efficiently used in retrofitting. Also damping coefficient value obtained is least for upper toggle-brace configuration out of the four different damper configurations suggesting this is the most efficient configuration for retrofitting.

Download or read book Seismic Analysis of Concrete Structures written by Shivaji Eknath Jagtap and published by . This book was released on 2009 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: A full scale seven-story reinforced concrete building, was tested on a shake table, at the National Earthquake Engineering Society's (NEES) facility at the University of California, San Diego during the period October 2005 through January 2006 using scaled acceleration time histories of the 1994 Northridge Earthquake, one of the strongest recorded motions. Numerically calculated parameters using a three dimensional finite element model of this structure by using commercially available software SAP2000 are compared with available experimental data from tests with the goal to propose a type of analyses which can accurately estimate all the necessary parameters for structural engineering industry. The methods studies include equivalent lateral force method, modal response spectrum analysis and nonlinear time history analysis consisting of fast non linear analysis and direct integration analysis.

Download or read book Advances in Computer Methods and Geomechanics written by Amit Prashant and published by Springer Nature. This book was released on 2020-01-14 with total page 735 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume presents selected papers from IACMAG Symposium,The major themes covered in this conference are Earthquake Engineering, Ground Improvement and Constitutive Modelling. This volume will be of interest to researchers and practitioners in geotechnical and geomechanical engineering.

Download or read book Seismic Analysis of a Three story Reinforced Concrete Building written by T. K. Lew and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: