Seismic fragility curves of steel structures including soil-structure interaction and variation of soil parameters

2021 ◽  
Vol 143 ◽  
pp. 106609
Author(s):  
M.R. Akhoondi ◽  
F. Behnamfar
Keyword(s):  
Soil Structure ◽  
Fragility Curves ◽  
Steel Structures ◽  
Soil Structure Interaction ◽  
Seismic Fragility ◽  
Soil Parameters ◽  
Structure Interaction

Seismic fragility assessment of multi-span concrete highway bridges in British Columbia considering soil–structure interaction

2021 ◽  
Vol 48 (1) ◽  
pp. 39-51 ◽  
Author(s):  
A.H.M. Muntasir Billah ◽  
M. Shahria Alam
Keyword(s):  
British Columbia ◽  
Soil Structure ◽  
Seismic Vulnerability ◽  
Structural Characteristics ◽  
Fragility Curves ◽  
Highway Bridges ◽  
System Level ◽  
Soil Structure Interaction ◽  
Seismic Fragility ◽  
Structure Interaction

Fragility curve is an effective tool for identifying the potential seismic risk and consequences during and after an earthquake. Recent seismic events have shown that bridges are highly sensitive and vulnerable during earthquakes. There has been limited research to evaluate the seismic vulnerability of the existing bridges in British Columbia (BC), which could help in the decision-making process for seismic upgrade. This study focuses on developing seismic fragility curves for typical multi-span continuous concrete girder bridges in BC. Ground motions compatible with the seismic hazard were used as input excitations for vulnerability assessment. Uncertainties in material and geometric properties were considered to represent the bridges with similar structural characteristics and construction period. The fragility of the bridge is largely attributable to the fragilities of the columns, and to a lesser extent, the abutment and bearing components. The results of this study show that, although not very significant, the soil–structure interaction has some effect on the component fragility where this effect is not very significant at the bridge system level.

scholarly journals Seismic Fragility Analysis of Buildings Based on Double-Parameter Damage Models considering Soil-Structure Interaction

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Panpan Zhai ◽  
Peng Zhao ◽  
Yang Lu ◽  
Chenying Ye ◽  
Feng Xiong
Keyword(s):  
Soil Structure ◽  
Fragility Curves ◽  
Damage Index ◽  
Fragility Analysis ◽  
Soil Structure Interaction ◽  
Seismic Fragility ◽  
Rc Buildings ◽  
Structure Interaction ◽  
Damage Models ◽  
Fixed Model

Most conventional seismic fragility analyses of RC buildings usually ignore or greatly simplify the soil-structure interaction (SSI), and the maximum interstory drift ratio (MIDR) is often adopted to establish seismic fragility curves. In this work, an eight-story RC building was designed to study the influence of the SSI on the seismic fragility of RC buildings. Three double-parameter damage models (DPDMs) were considered for the fragility assessment: the Park–Ang model, the Niu model, and the Lu–Wang model. Results show that considering SSI induces a higher fragility than that of the fixed model and that employing the DPDMs for the fragility analysis provides more reasonable results than those evaluated using the MIDR damage index.

Effect of Soil-Structure Interaction on the Seismic Fragility of a Nuclear Reactor Building

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Samer El-Bahey ◽  
Yasser Alzeni ◽  
Konstantinos Oikonomou
Keyword(s):  
Soil Structure ◽  
Power Plants ◽  
Fragility Curves ◽  
Free Field ◽  
Nuclear Industry ◽  
Soil Structure Interaction ◽  
Seismic Fragility ◽  
Lumped Mass ◽  
Structure Interaction ◽  
Reactor Building

Recently, the nuclear industry has made a tremendous effort to assess the safety of nuclear power plants (NPP), as advances in seismology have led to the perception that the potential earthquake hazard in the U.S. may be higher than originally assumed. Due to the conservatism in the NPP design, structures and safety-related items are capable of withstanding earthquakes larger than the safe shutdown earthquake (SSE). One major aspect of conservatism in the design is ignoring the effect of soil-structure interaction (SSI), which results in conservative estimates of seismic demands for plant equipment. In this paper, a typical reactor building (RB) is chosen for a case study to investigate the potential benefit of accounting for SSI effects. A lumped mass stick model is first developed and analyzed with a fixed base configuration, using the free-field ground motion as input at the foundation level, as well as with a SSI configuration. Fragility analyses are then performed for the RB and one of its components to quantify the effects of the SSI on the overall seismic risk. In each case, a family of seismic fragility curves is developed. It is found that consideration of SSI effects in the analysis can improve the component fragilities, and potentially enhance the core damage frequency (CDF) of the plant.

scholarly journals Response of Steel Moment and Braced Frames Subjected to Near-Source Pulse-Like Ground Motions by Including Soil-Structure Interaction Effects

2017 ◽  
Vol 3 (1) ◽  
pp. 15-34 ◽  
Author(s):  
Pooriya Ayough ◽  
Sara Mohamadi ◽  
Seyed Ali Haj Seiyed Taghia
Keyword(s):  
Seismic Response ◽  
High Frequency ◽  
Soil Structure ◽  
Steel Structures ◽  
Soil Structure Interaction ◽  
Ductility Demand ◽  
Structure Interaction ◽  
Near Fault ◽  
Frequency Components ◽  
Pulse Type

Most seismic regulations are usually associated with fixed-base structures, assuming that elimination of this phenomenon leads to conservative results and engineers are not obliged to use near-fault earthquakes. This study investigates the effect of soil–structure interaction on the inelastic response of MDOF steel structures by using well known Cone method. In order to achieve this, three dimensional multi-storey steel structures with moment and braced frame are analysed using non-linear time history method under the action of 40 near-fault records. Seismic response parameters, such as base shear, performance of structures, ductility demand and displacement demand ratios of structures subjected to different frequency-contents of near-fault records including pulse type and high-frequency components are investigated. The results elucidate that the flexibility of soil strongly affects the seismic response of steel frames. Soil–structure interaction can increase seismic demands of structures. Also, soil has approximately increasing and mitigating effects on structural responses subjected to the pulse type and high frequency components. A threshold period exists below which can highly change the ductility demand for short period structures subjected to near-fault records.

Seismic behavior of structures considering uplift and soil–structure interaction

2017 ◽  
Vol 20 (11) ◽  
pp. 1712-1726
Author(s):  
Farhad Behnamfar ◽  
Seyyed Mohammad Mirhosseini ◽  
Hossein Alibabaei
Keyword(s):  
Seismic Behavior ◽  
Soil Structure ◽  
Nonlinear Dynamic Analysis ◽  
Steel Structures ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Nonlinear Seismic Response ◽  
Tensile Forces ◽  
Fixed Base ◽  
Flexible Base

A common assumption when analyzing a structure for earthquake forces is that the building is positively attached to a rigid ground so that it can sustain possible tensile forces without being detached, or uplifted, from its bearing points. Considering the facts that almost no tension can be transferred between a surface foundation and soil and soft soils interact with the supported structure during earthquakes, in this research, the effects of uplift and soil–structure interaction on nonlinear seismic response of structures are evaluated. Several reinforced concrete and steel structures under different suits of consistent ground motions are considered. The base of the buildings is modeled with vertical no-tension springs being nonlinear in compression. The total soil–structure interaction system is modeled within OpenSees, and the seismic behavior is evaluated using a nonlinear dynamic analysis. The nonlinear responses of buildings are determined and compared between three cases: fixed base, flexible base without uplift, and flexible base with uplift. The cases for which uplift in conjunction with soil–structure interaction should be considered are identified.

Soil Structure Interaction Effects on Stability of HP/HT Unburied Subsea Pipelines Using a Probabilistic-Based Approach

2021 ◽  
Author(s):  
Davide Forcellini ◽  
Daniele Mina ◽  
Hassan Karampour
Keyword(s):  
Soil Structure ◽  
Seismic Vulnerability ◽  
Fragility Curves ◽  
Failure Criteria ◽  
Soil Structure Interaction ◽  
Pipeline System ◽  
Earthquake Scenario ◽  
Structure Interaction ◽  
Subsea Pipelines ◽  
Soil Behaviour

Abstract Soil structure interaction (SSI) may considerably affect the seismic vulnerability of subsea high pressure/high temperature (HP/HT) pipelines. Numerical simulations are herein proposed to study the effects of soil deformability on failure of an unburied pipeline with D/t = 20, laid on the seabed and resting on a sleeper. OpenSees is used to assess an earthquake scenario imposed on a laterally buckled pipeline by considering the effects of non-linear soil behaviour on the mechanisms that induce damage on the soil-pipeline system. Uncertainties in the case study were considered by applying a probabilistic-based approach and by developing analytical fragility curves that allow estimation of the probability of exceedance of the selected failure criteria.

Sign in / Sign up

Export Citation Format

Share Document