A Study of the Implications of Soil-structure Interaction Effects on the Seismic Response of High-rise Reinforced Concrete Buildings [microform] PDF Download

Author: Shamel Hosni
Publisher: National Library of Canada = Bibliothèque nationale du Canada
ISBN:
Category : Reinforced concrete construction
Languages : en
Pages : 187

View

Book Description

Author: Luis Gerardo Buitrago Goyez
Publisher:
ISBN:
Category : Earthquake engineering
Languages : en
Pages : 210

View

Book Description
The importance of soil-structure interaction (SSI) effects on the seismic response of buildings has been long recognized and has been researched for over 40 years. However, SSI analysis has only been applied in a few building projects because the fixed base condition is considered to provide a conservative estimation for the response of buildings under seismic loads. This assumption of a fixed base condition adopted by practitioners is not always conservative or cost-effective, especially for rigid buildings over soft soils. Additionally, for the case of ductile steel frames with eccentric configurations, the influence of SSI on their seismic performance has not been investigated. In this study, the seismic performance of eccentrically braced frames (EBFs) considering SSI effects is investigated using analytical models. Background information and modern guidelines available to consider SSI in the seismic analysis of buildings are presented and discussed. Following, a 3-story building with EBFs on shallow foundations is analyzed with and without SSI. The beam on Winkler foundation approach is used to model the linear and nonlinear soil-foundation interface behavior, considering linear-elastic, elastic-perfectly plastic, and nonlinear springs. Inter-story drifts, residual drifts, link rotations, and axial load column demands were similar for frames with flexible base and fixed base conditions when elastic and elastic-perfectly plastic springs were used. However, when nonlinear springs were used, frames with a flexible base showed a significant reduction in their responses in comparison to those observed for the fixed base condition. As a result, a reduction in frame member sizes was possible and justified through SSI analyses.

Author: Tom Schanz
Publisher: Springer Science & Business Media
ISBN: 9048126975
Category : Science
Languages : en
Pages : 320

View

Book Description
Proceedings of the NATO Advanced Research Workshop on Coupled Site and Soil-Structure Interaction Effects with Application to Seismic Risk Mitigation Borovets, Bulgaria 30 August - 3 September 2008

Author: Jaime A. Mercado
Publisher:
ISBN:
Category :
Languages : en
Pages : 175

View

Book Description
Soil-structure interaction (SSI) effects are relevant for the seismic analysis of tall buildings on shallow foundations since the dynamic behavior of structures is highly affected by the interaction between the superstructure and supporting soils. As part of earthquake-resistant designs of buildings, considering SSI effects in the analysis provides more realistic estimates of its performance during a seismic event, particularly when both the structure and soil undergo large demands that can compromise serviceability. Oversimplifications of structural or soil modeling in the analysis introduces variability and biases in the computed seismic response.

Author: C. Zhang
Publisher: Elsevier
ISBN: 0080530583
Category : Science
Languages : en
Pages : 335

View

Book Description
Dynamic Soil-structure interaction is one of the major topics in earthquake engineering and soil dynamics since it is closely related to the safety evaluation of many important engineering projects, such as nuclear power plants, to resist earthquakes. In dealing with the analysis of dynamic soil-structure interactions, one of the most difficult tasks is the modeling of unbounded media. To solve this problem, many numerical methods and techniques have been developed. This book summarizes the most recent developments and applications in the field of dynamic soil-structure interaction, both in China and Switzerland. An excellent book for scientists and engineers in civil engineering, structural engineering, geotechnical engineering and earthquake engineering.

Author: A.S. Cakmak
Publisher: Elsevier
ISBN: 044460040X
Category : Technology & Engineering
Languages : en
Pages : 382

View

Book Description
Despite advances in the field of geotechnical earthquake engineering, earthquakes continue to cause loss of life and property in one part of the world or another. The Third International Conference on Soil Dynamics and Earthquake Engineering, Princeton University, Princeton, New Jersey, USA, 22nd to 24th June 1987, provided an opportunity for participants from all over the world to share their expertise to enhance the role of mechanics and other disciplines as they relate to earthquake engineering. The edited proceedings of the conference are published in four volumes. This volume covers: Soil Structure Interaction under Dynamic Loads, Vibration of Machine Foundations, and Base Isolation in Earthquake Engineering. With its companion volumes, it is hoped that it will contribute to the further development of techniques, methods and innovative approaches in soil dynamics and earthquake engineering.

Author: Babak Kamranimoghaddam
Publisher:
ISBN: 9781369796209
Category :
Languages : en
Pages :

View

Book Description
This study investigates the seismic response and dynamic cross-interaction effects on two closely located nuclear power plants (NPP) to a range of seismic inputs with varying frequency content. A comprehensive study is undertaken to examine the effects of the location of the seismic source as well as the soil characteristics beneath the NPP on dynamic structure-soil-structure interaction (SSSI) between the adjacent structures. The effect of proximity of the NPP is also studied by varying the distance between the power plants. In the preliminary phase of the study, the significance of using three dimensional seismic waves in response evaluation of nuclear power plant buildings is demonstrated. First, the responses of a single power plant subjected to one-dimensional and three-dimensional waves are compared. This is followed by a similar series of analyses on closely located adjacent power plants. It is shown that using one-dimensional waves can lead to misrepresentation of the seismic response of the NPP and non-conservative estimates of seismic demands. In general, the variation in response between 1D and 3D waves was more significant for the containment building than the auxiliary structure. Findings from the preliminary phase of the study formed the basis for the next set of comprehensive simulations to investigate the dynamic cross-interaction between adjacent nuclear power plant buildings for three earthquake scenarios and three different soil conditions. Each scenario represents a different form of seismic wave caused by a near source earthquake. For each scenario, to evaluate the influence of site conditions, simulations are performed on soft, medium, and hard soil sites. In addition, the free distance between the adjacent buildings is varied to study the influence of the proximity of the structures to the SSSI effects. The primary findings from the study can be summarized as follows: (i) increasing the shear wave velocity of the site which increases the minimum wave length, reduces the dynamic cross interaction between the buildings; (ii) unlike the response of the auxiliary building which is influenced the most on hard soil sites, the response of the containment building is influenced mostly on softer soils; (iii) high frequencies are introduced in the response due to presence of the adjacent building which influences the dynamic SSSI effects; (iv) dynamic cross-interaction effects are different depending on whether the buildings are located upstream or downstream of the propagating seismic waves and response in the downstream building is generally (not necessarily) higher than the upstream one; (v) for deep near-source events, dynamic cross-interaction is observed in all components of the response whereas for shallow earthquakes, the response is mostly influenced in the direction of the wave propagation; and (vi) generally, but not necessarily, increasing the distance between the power plants decreases the dynamic cross interaction.

Author: Michael James Givens
Publisher:
ISBN:
Category :
Languages : en
Pages : 329

View

Book Description
The effects of soil-structure interaction (SSI) are investigated through careful interpretation of available data from instrumented buildings and recently performed forced vibration experiments on instrumented buildings and test structures. Conventional engineering practice typically ignores soil-structure interaction (SSI) during evaluation of the seismic demand on buildings based on the perception that consideration of SSI will reduce demands on structures and ignoring SSI effects will cause seismic demands to be conservatively biased. I show that it is not always conservative to ignore SSI effects. Analysis of field performance data is undertaken to provide deeper insights into SSI phenomena ranging from kinematic effects on foundation ground motions to mobilized foundation stiffness and damping across a wide range of frequencies and loading levels. These data are interpreted to evaluate strengths and limitations of engineering analysis procedures for SSI. Foundation damping incorporates the combined effects of energy loss due to waves propagating away from the vibrating foundation in translational and rotational modes (radiation damping), as well as hysteretic action in the soil (material damping). Previous foundation damping models were developed for rigid circular foundations on homogenous halfspace and were often expressed using confusing or incomplete functions. Starting from first principles, we derive fundamental expressions for foundation damping in which foundation impedance components representing radiation damping and the soil hysteretic damping ratio appear as variables, providing maximum flexibility to the analyst. We utilize these general expressions with impedance solutions for rectangular-footprint foundations to: (1) compare predicted foundation damping levels with those from field case histories and (2) develop new foundation damping relationships for application in the building code (NEHRP Provisions). Ground motions at the foundation levels of structures differ from those in the free-field as a result of inertial and kinematic interaction effects. Inertial interaction effects tend to produce narrow-banded ground motion modification near the fundamental period of the soil-structure system, whereas kinematic effects are relatively broad-banded but most significant at high frequencies. Kinematic interaction effects can be predicted using relatively costly finite element analyses with incoherent input or simplified models. The simplified models are semi-empirical in nature and derived from California data. These simplified models are the basis for seismic design guidelines used in the western United States, such as ASCE-41 and NIST (2012). We compile some available data from building and ground instrumentation arrays in Japan for comparison to these two sets of models. We demonstrate that the model predictions for the sites under consideration are very similar to each other for modest foundation sizes (equivalent radii under about 50 m). However, the data show that both approaches overestimate the transfer function ordinates relative to those from a subset of the Japanese buildings having pile foundations. The misfit occurs at frequencies higher than the first-mode resonant frequency and appears to result from pile effects on kinematic interaction that are not accounted for in current models. A complete model of a soil-foundation-structure system for use in response history analysis requires modification of input motions relative to those in the free-field to account for kinematic interaction effects, foundation springs and dashpots to represent foundation-soil impedance, and a structural model. The recently completed NIST (2012) report developed consistent guidelines for evaluation of kinematic interaction effects and foundation impedance for realistic conditions. We implement those procedures in seismic response history analyses for two instrumented buildings in California, one a 13-story concrete-moment frame building with two levels of basement and the other a 10-story concrete shear wall core building without embedment. We develop three-dimensional baseline models (MB) of the building and foundation systems (including SSI components) that are calibrated to reproduce observed responses from recorded earthquakes. SSI components considered in the MB model include horizontal and vertical springs and dashpots that represent the horizontal translation and rotational impedance, kinematic ground motion variations from embedment and base slab averaging, and ground motion variations over the embedment depth of basements. We then remove selected components of the MB models one at a time to evaluate their impact on engineering demand parameters (EDPs) such as inter-story drifts, story shear distributions, and floor accelerations. We find that a "bathtub" model that retains all features of the MB approach except for depth-variable motions provides for generally good above-ground superstructure responses, but biased demand assessments in subterranean levels. Other common approaches using a fixed-based representation can produce poor results. To expand the data inventory of response histories to evaluate SSI, we performed forced vibration testing of a well-instrumented steel and reinforced concrete structure that has removable bracing. The testing was performed at three sites with varying soil conditions. I describe testing at one of the sites located in Garner Valley, California. During testing at this site an adjacent structure and local concrete slab were also instrumented in addition to the test structure. I describe the testing setup, schemes, instrumentation, and data processing techniques. The data are analyzed to evaluate the stiffness and damping associated with the foundation-soil interaction, revealing linear-elastic behavior at low forcing levels characterized by smaller stiffnesses and both lower and higher damping than is predicted by classical models. Nonlinear behavior at stronger shaking levels includes pronounced reductions of stiffness and changes in damping. Interestingly, kinematic interaction effects observed on an adjacent slab excited principally by surface waves were of a similar character to expectations from analytical models for body wave excitation from earthquakes. If verified, these results could lead to site- and foundation-specific test methods for evaluating kinematic interaction effects.

Author: Polat Gülkan
Publisher: Springer Science & Business Media
ISBN: 9401117551
Category : Science
Languages : en
Pages : 446

View

Book Description
For the last couple of decades it has been recognized that the foundation material on which a structure is constructed may interact dynamically with the structure during its response to dynamic excitation to the extent that the stresses and deflections in the system are modified from the values that would have been developed if it had been on a rigid foundation. This phenomenon is examined in detail in the book. The basic solutions are examined in time and frequency domains and finite element and boundary element solutions compared. Experimental investigations aimed at correlation and verification with theory are described in detail. A wide variety of SSI problems may be formulated and solved approximately using simplified models in lieu of rigorous procedures; the book gives a good overview of these methods. A feature which often lacks in other texts on the subject is the way in which dynamic behavior of soil can be modeled. Two contributors have addressed this problem from the computational and physical characterization viewpoints. The book illustrates practical areas with the analysis of tunnel linings and stiffness and damping of pile groups. Finally, design code provisions and derivation of design input motions complete this thorough overview of SSI in conventional engineering practice. Taken in its entirety the book, authored by fifteen well known experts, gives an in-depth review of soil-structure interaction across a broad spectrum of aspects usually not covered in a single volume. It should be a readily useable reference for the research worker as well as the advance level practitioner. (abstract) This book treats the dynamic soil-structure interaction phenomenon across a broad spectrum of aspects ranging from basic theory, simplified and rigorous solution techniques and their comparisons as well as successes in predicting experimentally recorded measurements. Dynamic soil behavior and practical problems are given thorough coverage. It is intended to serve both as a readily understandable reference work for the researcher and the advanced-level practitioner.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

View

Book Description
The Process, Purification and Stack Buildings are collocated safety related concrete shear wall structures with plan dimensions in excess of 100 feet. An important aspect of their seismic analysis was the determination of structure soil structure interaction (SSSI) effects, if any. The SSSI analysis of the Process Building, with one other building at a time, was performed with the SASSI computer code for up to 50 frequencies. Each combined model had about 1500 interaction nodes. Results of the SSSI analysis were compared with those from soil structure interaction (SSI) analysis of the individual buildings, done with ABAQUS and SASSI codes, for three parameters: peak accelerations, seismic forces and the in-structure floor response spectra (FRS). The results may be of wider interest due to the model size and the potential applicability to other deep soil layered sites. Results obtained from the ABAQUS analysis were consistently higher, as expected, than those from the SSI and SSSI analyses using the SASSI. The SSSI effect between the Process and Purification Buildings was not significant. The Process and Stack Building results demonstrated that under certain conditions a massive structure can have an observable effect on the seismic response of a smaller and less stiff structure.