scholarly journals Probabilistic Risk Assessment: Piping Fragility due to Earthquake Fault Mechanisms

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Bu Seog Ju ◽  
WooYoung Jung ◽  
Myung-Hyun Noh
Keyword(s):  
Risk Assessment ◽  
Fire Protection ◽  
Ground Motions ◽  
Normal Fault ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Piping System ◽  
Earthquake Fault ◽  
Piping Systems ◽  
Fault Mechanism

A lifeline system, serving as an energy-supply system, is an essential component of urban infrastructure. In a hospital, for example, the piping system supplies elements essential for hospital operations, such as water and fire-suppression foam. Such nonstructural components, especially piping systems and their subcomponents, must remain operational and functional during earthquake-induced fires. But the behavior of piping systems as subjected to seismic ground motions is very complex, owing particularly to the nonlinearity affected by the existence of many connections such as T-joints and elbows. The present study carried out a probabilistic risk assessment on a hospital fire-protection piping system’s acceleration-sensitive 2-inch T-joint sprinkler components under seismic ground motions. Specifically, the system’s seismic capacity, using an experimental-test-based nonlinear finite element (FE) model, was evaluated for the probability of failure under different earthquake-fault mechanisms including normal fault, reverse fault, strike-slip fault, and near-source ground motions. It was observed that the probabilistic failure of the T-joint of the fire-protection piping system varied significantly according to the fault mechanisms. The normal-fault mechanism led to a higher probability of system failure at locations 1 and 2. The strike-slip fault mechanism, contrastingly, affected the lowest fragility of the piping system at a higher PGA.

scholarly journals Fragility Assessments of Multi-Story Piping Systems within a Seismically Isolated Low-Rise Building

2018 ◽  
Vol 10 (10) ◽  
pp. 3775 ◽  
Author(s):  
Yonghee Ryu ◽  
Shinyoung Kwag ◽  
Bu‐Seog Ju
Keyword(s):  
Seismic Isolation ◽  
Ground Motions ◽  
Seismic Energy ◽  
Analytical Models ◽  
Piping System ◽  
Building Structure ◽  
Strong Ground Motions ◽  
Piping Systems ◽  
Seismically Isolated ◽  
Strong Ground

A successful, advanced safety design method for building and piping structures is related to its functionality and sustainability in beyond-design-basis events such as extremely strong ground motions. This study develops analytical models of seismically isolated building-piping systems in which multi-story piping systems are installed in non-isolated and base-isolated, low-rise buildings. To achieve the sustainable design of a multi-story piping system subjected to strong ground motions, Triple Friction Pendulum (TFP) elements, specifically TFP bearings, were incorporated into the latter building structure. Then, a seismic fragility analysis was performed in consideration of the uncertainty of the seismic ground motions, and the piping fragilities for the seismically non-isolated and the base-isolated building models were quantified. Here, the failure probability of the piping system in the non-isolated building was greater than that in the seismically isolated building. The seismic isolation design of the building improved the sustainability and functionality of the piping system by significantly reducing the seismic energy of extreme ground motions which was input to the building structure itself.

scholarly journals Earthquakes in Switzerland and surrounding regions during 2017 and 2018

2021 ◽  
Vol 114 (1) ◽  
Author(s):  
Tobias Diehl ◽  
John Clinton ◽  
Carlo Cauzzi ◽  
Toni Kraft ◽  
Philipp Kästli ◽  
...  
Keyword(s):  
Ground Motions ◽  
Structural Complexity ◽  
Normal Fault ◽  
Strike Slip ◽  
Crystalline Basement ◽  
Border Region ◽  
Thrust Faulting ◽  
Fold And Thrust Belt ◽  
Aar Massif ◽  
Alpine Foreland

AbstractThis report summarizes the seismicity in Switzerland and surrounding regions in the years 2017 and 2018. In 2017 and 2018, the Swiss Seismological Service detected and located 1227 and 955 earthquakes in the region under consideration, respectively. The strongest event in the analysed period was the ML 4.6 Urnerboden earthquake, which occurred in the border region of cantons Uri, Glarus and Schwyz on March 6, 2017. The event was the strongest earthquake within Switzerland since the ML 5.0 Vaz earthquake of 1991. Associated ground motions indicating intensity IV were reported in a radius up to about 50 km and locally approached intensity VI in the region close to the epicentre. Derived focal mechanisms and relative hypocentre relocations of the immediate aftershocks image a NNW–SSE striking sinistral strike-slip fault. Together with other past events in this region, the Urnerboden earthquake suggests the existence of a system of sub-parallel strike-slip faults, likely within in the uppermost crystalline basement of the eastern Aar Massif. A vigorous earthquake sequence occurred close to Château-d'Oex in the Préalpes-Romandes region in western Switzerland. With a magnitude of ML 4.3, the strongest earthquake of the sequence occurred on July 1, 2017. Focal mechanism and relative relocations of fore- and aftershocks image a NNE dipping normal fault in about 4 km depth. Two similarly oriented shallow normal-fault events occurred between subalpine Molasse and Préalpes units close to Châtel-St-Denis and St. Silvester in 2017/18. Together, these events indicate a domain of NE–SW oriented extensional to transtensional deformation along the Alpine Front between Lake Geneva in the west and the Fribourg Fault in the east. The structural complexity of the Fribourg Fault is revealed by an ML 2.9 earthquake near Tafers in 2018. The event images a NW–SE striking fault segment within the crystalline basement, which might be related to the Fribourg Fault Zone. Finally, the ML 2.8 Grenchen earthquake of 2017 provides a rare example of shallow thrust faulting along the Jura fold-and-thrust belt, indicating contraction in the northwestern Alpine foreland of Switzerland.

Statistics of Ground Motions in a Foam Rubber Model of a Strike‐Slip Fault

2015 ◽  
Vol 105 (3) ◽  
pp. 1456-1467
Author(s):  
Kevin M. McBean ◽  
John G. Anderson ◽  
James N. Brune ◽  
Rasool Anooshehpoor
Keyword(s):  
Ground Motions ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Foam Rubber ◽  
Rubber Model

scholarly journals Analisa Pola Sesar Di Daratan Selatan Sumatera Berdasarkan Event Gempa Tahun 1960-2000

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
A. M Miftahul Huda ◽  
Badrul Munir
Keyword(s):  
Moment Tensor ◽  
Normal Fault ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Reverse Fault

Analisa pola sesar telah dilakukan untuk wilayah sumatera bagian selatan melalui analisis data kegempaan. Data kegempaan yang digunakan adalah data ISC dan dikombinasikan dengan data fokal dari Global CMT dari tahun 1960-2000. Penelitian ini dilakukan dalam tiga tahap, yaitu penentuan persebaran kegempaan, penentuan moment tensor melalui data fokal, dan korelasi data dengan data geologi. Pada posisi geografis 1040-1060 BT terdapat 7 gempa signifikan sepanjang tahun 1960 sampai tahun 2000, diantaranya 3 sesar mendatar (strike slip fault), 1 sesar naik (reverse fault), 1 sesar turun (normal fault) dan 2 sesar oblique. Anomali data terjadi pada seismisitas kegempaan tahun 1960-2000, yaitu teramatinya sesar oblique. Aktifitas kegempaan dipengaruhi oleh aktifitas sesar Sumatera dari Andaman sampai Semangko. Kata kunci: pola sesar, gempa tektonik, fokal, oblique

Reassessing the in-situ stress regimes of Australia's petroleum basins

2012 ◽  
Vol 52 (1) ◽  
pp. 415 ◽  
Author(s):  
Rosalind King ◽  
Simon Holford ◽  
Richard Hillis ◽  
Adrian Tuitt ◽  
Ernest Swierczek ◽  
...  
Keyword(s):  
Late Miocene ◽  
Normal Fault ◽  
In Situ Stress ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Normal Faults ◽  
Reverse Fault ◽  
Stress Regime ◽  
Reverse Faulting

Previous in-situ stress studies across many of Australia’s petroleum basins demonstrate normal fault and strike-slip fault stress regimes, despite the sedimentary successions demonstrating evidence for widespread Miocene-to-Recent reverse faulting. Seismic and outcrop data demonstrate late Miocene-to-Recent reverse or reverse-oblique faulting in the Otway and Gippsland basins. In the Otway Basin, a series of approximately northeast to southwest trending anticlines related to reverse-reactivation of deep syn-rift normal faults, resulting in the deformation of Cenozoic post-rift sediments are observed. Numerous examples of late Miocene-to-Recent reverse faulting in the offshore Gippsland Basin have also been observed, with contractional reactivation of previously normal faults during these times partially responsible for the formation of anticlinal hydrocarbon traps that host the Barracouta, Seahorse and Flying Fish hydrocarbon fields, adjacent to the Rosedale Fault System. A new method for interpreting leak-off test data demonstrates that the in-situ stress data from parts of the Otway and Gippsland basins can be reinterpreted to yield reverse fault stress regimes, consistent with the present-day tectonic setting of the basins. This reinterpretation has significant implications for petroleum exploration and development in the basins. In the Otway and Gippsland basins, wells drilled parallel to the orientation of the maximum horizontal stress (σH) represent the safest drilling directions for both borehole stability and fluid losses. Faults and fractures, striking northeast to southwest, previously believed to be at low risk of reactivation in a normal fault or strike-slip fault stress regime are now considered to be at high risk in the reinterpreted reverse fault stress regime.

Seismic Evaluation Methods for Fire Protection Sprinkler Piping Systems in Buildings

2019 ◽  
Author(s):  
Fan-Ru Lin ◽  
Juin-Fu Chai ◽  
Yung-An Tsai ◽  
Chang-Chen Yeh ◽  
Kuo-Chun Chang
Keyword(s):  
Fire Protection ◽  
Evaluation Method ◽  
Sprinkler System ◽  
Shaking Table ◽  
Fragility Analysis ◽  
Piping System ◽  
Shaking Table Tests ◽  
Seismic Evaluation ◽  
Sprinkler Systems ◽  
Piping Systems

Abstract Based on recent earthquakes experiences in Taiwan, losses do not necessarily result from damages of building structures but non-structural components. For instance, the leakage of the fire protection sprinkler systems in hospitals during small earthquakes could results in shortage of medical function and fire protection, and malfunction and repairs of medical equipment. The break of sprinkler systems caused by strong earthquakes could even harm the life safety. Taking a medium-scale hospital as an example, this research aims to conduct a simplified seismic evaluation method to improve seismic performance of the fire protection sprinkler system in critical buildings. The content of this research is summarized below: 1. Numerical analysis of the sample sprinkler piping system: a detailed numerical model of the fire protection sprinkler system in the sample hospital was established with SAP2000 v.20 software. Proper parameters to simulate the threaded joint of piping and the gap between adjacent partition walls or ceiling systems were proposed and verified by the results of component tests and shaking table tests. Ambient vibration tests in the sample hospital were conducted with velocimeters to clarify the structural characteristics of the building structure and the sprinkler piping system. 2. Fragility analysis of sprinkler piping systems: seismic fragility curves the fire protection sprinkler system in the sample hospital were conducted according to a mount of detailed analysis results and verified by the real damage state under Jiaxian earthquake. The effects of engineering demand parameters and categories of ground motion on fragility results are discussed for three types of failure modes. 3. Simplified seismic evaluation method for sprinkler piping systems: according to the results of shaking table tests and detailed analysis, a reliable simplified evaluation method was established to predict seismic behavior of typical sprinkler piping systems in hospitals by the information obtained from in-situ survey. The conservative level and accuracy of simplified evaluation results were verified by comparing the results of fragility analysis of numerical model and simplified evaluation.

Parametric study of near-field ground motions for oblique-slip and dip-slip dislocation models

1983 ◽  
Vol 73 (1) ◽  
pp. 45-57 ◽  
Author(s):  
John G. Anderson ◽  
J. Enrique Luco
Keyword(s):  
Ground Motions ◽  
Near Field ◽  
Thrust Fault ◽  
Strike Slip ◽  
Strike Slip Fault ◽  
Dislocation Model ◽  
Finite Width ◽  
Rupture Velocity ◽  
Slip Direction ◽  
Dislocation Models

abstract The near-field motion on the surface of a uniform half-space for oblique-slip and dip-slip faults has been studied by the use of a dislocation model. The fault is modeled by an infinitely long buried dislocation of finite width; rupture propagates horizontally along the fault and past the observation points with a constant rupture velocity lower than the Rayleigh wave velocity. In addition to those parameters which control peak amplitudes near a vertical, strike-slip fault (depth of the top of the fault, horizontal rupture velocity), the dip of the fault plays an important role. The slip direction and the angle between the rupture front and the down-dip direction of the fault also become increasingly important in determining amplitudes of peak ground motions as the dip of the fault decreases from vertical to shallow angles. In some regions near a thrust fault, peak amplitudes are significantly greater than the largest values near a vertical, strike-slip fault.

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