scholarly journals The Role of Soil Structure Interaction in the Fragility Assessment of HP/HT Unburied Subsea Pipelines

2022 ◽  
Vol 10 (1) ◽  
pp. 110
Author(s):  
Davide Forcellini ◽  
Daniele Mina ◽  
Hassan Karampour

Subsea high pressure/high temperature (HP/HT) pipelines may be significantly affected by the effects of soil structure interaction (SSI) when subjected to earthquakes. Numerical simulations are herein applied to assess the role of soil deformability on the seismic vulnerability of an unburied pipeline. Overcoming most of the contributions existing in the literature, this paper proposes a comprehensive 3D model of the system (soil + pipeline) by performing OpenSees that allows the representation of non-linear mechanisms of the soil and may realistically assess the induced damage caused by the mutual interaction of buckling and seismic loads. Analytical fragility curves are herein derived to evaluate the role of soil structure interaction in the assessment of the vulnerability of a benchmark HP/HT unburied subsea pipeline. The probability of exceeding selected limit states was based on the definition of credited failure criteria.

2021 ◽  
Author(s):  
Davide Forcellini ◽  
Daniele Mina ◽  
Hassan Karampour

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.


2020 ◽  
Vol 16 (1) ◽  
pp. 39-48
Author(s):  
Parham Bakhtiari ◽  
Khosro Bargi

AbstractThe assessment of the seismic behavior of the high-speed railway bridges is necessary because of the strategic essence of these structures. Evaluating and predicting damages of the bridges that originated by earthquakes with various intensities can provide useful information, which is very helpful in the management of the possible crises. One of the most useful mechanisms for estimating earthquake damages to these bridges is the development of fragility curves for them. Studies on the production of fragility curves on the high-speed railway bridges are limited. In this research, the fragility curve is plotted for two high-speed railway bridges with different pier heights. Due to the differences in the height of these bridges, a comparison of the performance of these structures is also shown. The model of the high-speed railway bridge was created for each model separately in the SeismoStruct software. The soil-structure interaction is also modeled as springs, and its effects are considered. Nonlinear models are also used to model concrete and steel materials. Then, the incremental dynamic analysis was performed under different ground motion records. By using the obtained data from the analysis, appropriate damage states were selected, and finally, the fragility curves were plotted for different performance limit states. The results showed that with increasing pier height, the damage index was raised and for a constant probability of exceedance, the taller pier is demanded a lower spectral acceleration to achieve a performance level.


2021 ◽  
Vol 48 (1) ◽  
pp. 39-51 ◽  
Author(s):  
A.H.M. Muntasir Billah ◽  
M. Shahria Alam

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.


2019 ◽  
Vol 24 (7) ◽  
pp. 05019008 ◽  
Author(s):  
Giulio Zani ◽  
Paolo Martinelli ◽  
Andrea Galli ◽  
Carmelo Gentile ◽  
Marco di Prisco

Geosciences ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 229 ◽  
Author(s):  
Davide Forcellini

The seismic vulnerability of structures is closely related to changes in the degree of soil saturation that may cause significant changes in volume and shear strength, and consequently, bearing capacity. This paper aims to consider this issue during the strong earthquake that struck Southern Italy on 23 November 1980 (Ms = 6.9) and affected the Campania and Basilicata regions. Several 3D numerical finite element models were performed in order to consider the effects of soil–structure interaction (SSI) on a representative benchmark structure. In particular, the role of the water level depth is herein considered as one of the most significant parameters to control the shear deformations inside the soil, and thus the performance of the superstructure. Results show the importance of considering the water level for buildings on shallow foundations in terms of settlements, base shear forces and floor displacements.


Nanophotonics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1591-1605 ◽  
Author(s):  
Stéphane Brûlé ◽  
Stefan Enoch ◽  
Sébastien Guenneau

AbstractThe discovery of photonic crystals 30 years ago in conjunction with research advances in plasmonics and metamaterials, has inspired the concept of decameter scale metasurfaces, coined seismic metamaterials for an enhanced control of surface (Love and Rayleigh) and bulk (shear and pressure) elastodynamic waves. These powerful mathematical tools of coordinate transforms, effective medium and Floquet-Bloch theories which have revolutionized nanophotonics, can be translated in the language of civil engineering and geophysics. Experiments on seismic metamaterials made of buried elements in the soil demonstrate that the fore mentioned tools make a possible novel description of complex phenomena of soil-structure interaction during a seismic disturbance. But the concepts are already moving to more futuristic concepts and the same notions developed for structured soils are now used to examine the effects of buildings viewed as above surface resonators in megastructures such as metacities. But this perspective of future should not make us forget the heritage of the ancient peoples. Indeed, we finally point out the striking similarity between an invisible cloak design and the architecture of some ancient megastructures as the antique Gallo-Roman theaters and amphitheatres.


Sign in / Sign up

Export Citation Format

Share Document