Seismic Code Decisions under Risk: The Wasatch Front Illustration

1992 ◽  
Vol 8 (1) ◽  
pp. 35-55
Author(s):  
Craig E. Taylor ◽  
Lawrence D. Reaveley ◽  
Craig W. Tillman ◽  
Allan R. Porush

Regions of low-to-moderate seismicity but high catastrophic earthquake loss potential pose special issues with respect to seismic design codes as well as other significant policy decisions. These seismic design code decisions hinge on the amount of initial costs and on the size and certainty of benefits from increased design requirements. Since these decisions are made by government officials, these costs and benefits are distributed among various stakeholders in the community. This paper explains this perspective and clarifies earthquake risk methods needed to address these seismic design force level decisions in the Wasatch Front, Utah and, as a point of comparison, to the City of Los Angeles. These applications strengthen the case for a seismic zone 4 designation along the Wasatch Front but also raise issues about the roles of life-safety protection and certainty of benefits in seismic code decisions.

2018 ◽  
Author(s):  
Wooil Choi ◽  
Jae-Woo Park ◽  
Jinhwan Kim

Abstract. After the 2016 Gyeongju earthquake and the 2017 Pohang earthquake struck the Korean peninsula, securing financial stability for earthquake risk has become an important issue in Korea. Many domestic researchers are currently studying potential earthquake risk. However, empirical analysis and statistical approach are ambiguous in the case of Korea because no major earthquake has ever occurred on the Korean peninsula since Korean Meteorological Agency started monitoring earthquakes in 1978. This study focuses on evaluating possible losses due to earthquake risk in Seoul, the capital of Korea, by using catastrophe model methodology integrated with GIS (Geographic Information System). The building information such as structure and location is taken from the building registration database and the replacement cost for building is obtained from insurance information. As the seismic design code in KBC (Korea Building Code) is similar to the seismic design code of UBC (Uniform Building Code), the damage functions provided by HAZUS-MH are used to assess the damage state of each building in event of an earthquake. 12 earthquake scenarios are evaluated considering the distribution and characteristics of active fault zones in the Korean peninsula, and damages with loss amounts are calculated for each of the scenarios.


2019 ◽  
Vol 19 (5) ◽  
pp. 985-997
Author(s):  
Wooil Choi ◽  
Jae-Woo Park ◽  
Jinhwan Kim

Abstract. After the 2016 Gyeongju earthquake and the 2017 Pohang earthquake struck the Korean peninsula, securing financial stability regarding earthquake risks has become an important issue in South Korea. Many domestic researchers are currently studying potential earthquake risk. However, empirical analyses and statistical approaches are ambiguous in the case of South Korea because no major earthquake has ever occurred on the Korean peninsula since the Korean Meteorological Agency started monitoring earthquakes in 1978. This study focuses on evaluating possible losses due to earthquake risk in Seoul, the capital of South Korea, by using a catastrophe model methodology integrated with GIS (Geographic Information Systems). Building information, such as structure and location, is taken from the building registration database and the replacement cost for buildings is obtained from insurance information. As the seismic design code in the KBC (Korea Building Code) is similar to the seismic design code of the UBC (Uniform Building Code), the damage functions provided by HAZUS-Multi-hazard (HAZUS-MH) are used to assess the damage state of each building in event of an earthquake. A total of 12 earthquake scenarios are evaluated by considering the distribution and characteristics of active fault zones on the Korean peninsula and damages, with total loss amounts are calculated for each of the scenarios. The results of this study show that loss amounts due to potential earthquakes are significantly lower than those of previous studies. The challenge of this study is to implement an earthquake response spectrum and to reflect the actual asset value of buildings in Seoul.


2016 ◽  
Vol 32 (4) ◽  
pp. 2271-2289
Author(s):  
Sang Whan Han ◽  
Yu Jin Park ◽  
Sung Jin Ha

Steel intermediate moment frames (IMF) have been widely used as a seismic force resisting system in regions of low and moderate seismicity. In this study, the seismic collapse performance of the steel IMFs designed according to current seismic code was evaluated. For this purpose, 25 steel IMFs were designed according to seismic design codes (ASCE 7-10, AISC 341-10, and AISC 360-10), and the probability of collapse for these frames was estimated. The probability of collapse of steel IMFs became larger with an increase in the height of the frames. Based on the results, this study investigated the validity of height limits for steel IMFs specified in ASCE 7-10 and proposed limits to guarantee satisfactory seismic collapse performance.


2021 ◽  
Vol 4 (4) ◽  
pp. 89
Author(s):  
Ercan Işık ◽  
Ehsan Harirchian ◽  
Aydın Büyüksaraç ◽  
Yunus Levent Ekinci

Seismic hazard analysis of the earthquake-prone Eastern Anatolian Region (Turkey) has become more important due to its growing strategic importance as a global energy corridor. Most of the cities in that region have experienced the loss of life and property due to significant earthquakes. Thus, in this study, we attempted to estimate the seismic hazard in that region. Seismic moment variations were obtained using different types of earthquake magnitudes such as Mw, Ms, and Mb. The earthquake parameters were also determined for all provincial centers using the earthquake ground motion levels with some probabilities of exceedance. The spectral acceleration coefficients were compared based on the current and previous seismic design codes of the country. Additionally, structural analyses were performed using different earthquake ground motion levels for the Bingöl province, which has the highest peak ground acceleration values for a sample reinforced concrete building. The highest seismic moment variations were found between the Van and Hakkari provinces. The findings also showed that the peak ground acceleration values varied between 0.2–0.7 g for earthquakes, with a repetition period of 475 years. A comparison of the probabilistic seismic hazard curves of the Bingöl province with the well-known attenuation relationships showed that the current seismic design code indicates a higher earthquake risk than most of the others.


2006 ◽  
Vol 1 (3) ◽  
pp. 341-356 ◽  
Author(s):  
Hiroshi Kuramoto ◽  

Two revised seismic design codes in the Building Standard Law of Japan, which were revised in 1981 and 2000, are simply reviewed with the transition of Japanese seismic design code in this paper. The central feature of the seismic code revised in 1981 was the introduction of a two-phase earthquake design. Allowable stress design was employed for first-phase earthquake design targeting the safety and serviceability of buildings during medium-level earthquake activity. Second-phase earthquake design, which is ultimate strength design, was added to provide safety against severe earthquake motion. On the other hand, the seismic code revised in 2000 precisely defines performance requirements and verification based on accurate earthquake response and limit states of a building. The capacity spectrummethod is used for evaluating the earthquake response. The code is applicable to any type of material and buildings such as seismic isolation systems as long as material properties are well defined and structural behavior is appropriately estimated.


2021 ◽  
Vol 11 (6) ◽  
pp. 2652
Author(s):  
Jung Han Kim ◽  
Ick-Hyun Kim ◽  
Jin Ho Lee

When a seismic force acts on bridges, the pier can be damaged by the horizontal inertia force of the superstructure. To prevent this failure, criteria for seismic reinforcement details have been developed in many design codes. However, in moderate seismicity regions, many existing bridges were constructed without considering seismic detail because the detailed seismic design code was only applied recently. These existing structures should be retrofitted by evaluating their seismic performance. Even if the seismic design criteria are not applied, it cannot be concluded that the structure does not have adequate seismic performance. In particular, the performance of a lap-spliced reinforcement bar at a construction joint applied by past practices cannot be easily evaluated analytically. Therefore, experimental tests on the bridge piers considering a non-seismic detail of existing structures need to be performed to evaluate the seismic performance. For this reason, six small scale specimens according to existing bridge piers were constructed and seismic performances were evaluated experimentally. The three types of reinforcement detail were adjusted, including a lap-splice for construction joints. Quasi-static loading tests were performed for three types of scale model with two-column piers in both the longitudinal and transverse directions. From the test results, the effect on the failure mechanism of the lap-splice and transverse reinforcement ratio were investigated. The difference in failure characteristics according to the loading direction was investigated by the location of plastic hinges. Finally, the seismic capacity related to the displacement ductility factor and the absorbed energy by hysteresis behavior for each test were obtained and discussed.


2020 ◽  
Vol 10 (24) ◽  
pp. 9150
Author(s):  
Hyung-Joon Kim ◽  
Dong-Hyeon Shin

The promising seismic response emerged by the concept of base isolation leads to increasing practical applications into buildings located at low-to-moderate seismicity regions. However, it is questionable that their collapse capacities can be ensured with reasonable reliability, although they would be designed according to a current seismic design code. This paper aims to investigate the collapse capacities of isolated buildings governed by the prescribed design criteria on the displacement and strength capacities of the employed isolation systems. In order to evaluate their collapse capacity under maximum considered earthquakes (MCEs), simplified numerical models are constructed for a larger number of nonlinear incremental dynamic analyses. The influential factors on the collapse probabilities of the prototype buildings are found out to specifically suggest the potential modifications of the design requirements. Although the MCE collapse probabilities of all isolated buildings are smaller than those expected for typical non-isolated buildings, these values are significantly different according to the degree of seismicity. The MCE collapse probabilities are dependent upon the governing collapse mechanism and the total system uncertainty. For the prototype buildings located at low-to-moderate seismicity regions, this study proposed the acceptable uncertainty to achieve a similar collapse performance to the corresponding buildings built at high seismicity regions.


2021 ◽  
pp. 875529302098196
Author(s):  
Siamak Sattar ◽  
Anne Hulsey ◽  
Garrett Hagen ◽  
Farzad Naeim ◽  
Steven McCabe

Performance-based seismic design (PBSD) has been recognized as a framework for designing new buildings in the United States in recent years. Various guidelines and standards have been developed to codify and document the implementation of PBSD, including “ Seismic Evaluation and Retrofit of Existing Buildings” (ASCE 41-17), the Tall Buildings Initiative’s Guidelines for Performance-Based Seismic Design of Tall Buildings (TBI Guidelines), and the Los Angeles Tall Buildings Structural Design Council’s An Alternative Procedure for Seismic Analysis and Design of Tall Buildings Located in the Los Angeles Region (LATBSDC Procedure). The main goal of these documents is to regularize the implementation of PBSD for practicing engineers. These documents were developed independently with experts from varying backgrounds and organizations and consequently have differences in several degrees from basic intent to the details of the implementation. As the main objective of PBSD is to ensure a specified building performance, these documents would be expected to provide similar recommendations for achieving a given performance objective for new buildings. This article provides a detailed comparison among each document’s implementation of PBSD for reinforced concrete buildings, with the goal of highlighting the differences among these documents and identifying provisions in which the designed building may achieve varied performance depending on the chosen standard/guideline. This comparison can help committees developing these documents to be aware of their differences, investigate the sources of their divergence, and bring these documents closer to common ground in future cycles.


2010 ◽  
Vol 452-453 ◽  
pp. 105-108 ◽  
Author(s):  
Hong Fu Chen ◽  
Bai Tao Sun

During Wenchuan Ms 8.0 earthquake, masonry buildings have suffered severely damaged and collapsed, causing heavy casualties and huge economic losses. In this paper, based on seismic site survey data, some new phenomena and characteristics of earthquake damage in comparison with the 1976 Tangshan earthquake, such as seismic damage of large space buildings, inclined or “X” shaped crack in wall between windows or spandrel wall, stair damage, falling of precast reinforced concrete slab and horizontal crack at the bottom of structure, are discussed in detail. Then, the impact factors of seismic capacity of masonry building in Wenchuan earthquake, including construction age, seismic fortification, bay size, floor (roof) form, layer number, thickness of bearing wall are analyzed, respectively; Finally, some recommendations on seismic design and reconstruction of masonry structure by the seismic design code are proposed.


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