Seismic Analysis of Typical Cut-and-Cover Subway Stations in Beijing

2011 ◽  
Vol 90-93 ◽  
pp. 2200-2206
Author(s):  
Jing Bo Liu ◽  
Dong Dong Zhao ◽  
Wen Hui Wang
Keyword(s):  
Peak Ground Acceleration ◽  
Seismic Analysis ◽  
Relative Displacement ◽  
High Ratio ◽  
Underground Structures ◽  
Ground Acceleration ◽  
Analysis And Design ◽  
Side Walls ◽  
Subway Stations ◽  
Lower Ratio

To obtain the seismic responses of typical subway stations in Beijing, a nonlinear analysis was conducted using a pushover method for seismic analysis and design of underground structures. The analysis mainly focuses on stress in columns and side walls and relative displacement between top and bottom slabs under 3 different levels of PGA (peak ground acceleration). From the analysis, the column shows good ductility due to its high ratio of reinforcement, and it has a good performance under strong motions. Compared with columns, side walls suffer from brittle failure and lose bearing capacity prior to column for its lower ratio of reinforcement. The calculated displacement indicates that the relative displacement between top and bottom slabs is linear proportional to peak ground relative displacement (PGRD). And compared with peak ground acceleration (PGA), PGRD is a more reliable design parameter of ground motion for underground structures. And the typical subway stations in Beijng can withstand the earthquake with design PGA up to 0.2 g.

scholarly journals Vertical Seismic Effect on the Seismic Fragility of Large-Space Underground Structures

2019 ◽  
Vol 2019 ◽  
pp. 1-17 ◽  
Author(s):  
Zhiming He ◽  
Qingjun Chen
Keyword(s):  
Peak Ground Acceleration ◽  
Fragility Curves ◽  
Underground Structure ◽  
Seismic Effect ◽  
Peak Ground Velocity ◽  
Seismic Fragility ◽  
Vertical Acceleration ◽  
Underground Structures ◽  
Ground Acceleration ◽  
Large Space

The measured vertical peak ground acceleration was larger than the horizontal peak ground acceleration. It is essential to consider the vertical seismic effect in seismic fragility evaluation of large-space underground structures. In this research, an approach is presented to construct fragility curves of large-space underground structures considering the vertical seismic effect. In seismic capacity, the soil-underground structure pushover analysis method which considers the vertical seismic loading is used to obtain the capacity curve of central columns. The thresholds of performance levels are quantified through a load-drift backbone curve model. In seismic demand, it is evaluated through incremental dynamic analysis (IDA) method under the excitation of horizontal and vertical acceleration, and the soil-structure-interaction and ground motion characteristics are also considered. The IDA results are compared in terms of peak ground acceleration and peak ground velocity. To construct the fragility curves, the evolutions of performance index versus the increasing earthquake intensity are performed, considering related uncertainties. The result indicates that if we ignore the vertical seismic effect to the fragility assessment of large-space underground structures, the exceedance probabilities of damage of large-space underground structures will be underestimated, which will result in an unfavorable assessment result.

A study on the improvement of seismic coefficients for pseudo static analysis of gravity type quay wall via dynamic centrifuge tests

2020 ◽  
Author(s):  
Moon-Gyo Lee ◽  
Hyung-Ik Cho ◽  
Chang-Guk Sun ◽  
Han-Saem Kim
Keyword(s):  
Dynamic Behavior ◽  
Seismic Analysis ◽  
Inertial Force ◽  
Gravitational Acceleration ◽  
Ground Acceleration ◽  
Natural Period ◽  
The Real ◽  
Analysis And Design ◽  
Centrifuge Tests ◽  
Quay Wall

<p>The pseudo-static approach has been conventionally applied for the design of gravity type quay walls. In this method, the seismic coefficient (<em>k<sub>h</sub></em>), expressed in terms of acceleration due to gravity, is used to convert the real dynamic behavior to an equivalent pseudo-static inertial force for seismic analysis and design. The existing <em>k<sub>h</sub></em> is simply defined as the expected peak ground acceleration (<em>PGA</em>) of the ground divided by the gravitational acceleration (<em>g</em>), which does not sufficiently reflect the real dynamic behavior. In order to improve the <em>k<sub>h</sub></em> definition, a number of studies have been performed for reducing the differences between pseudo-static and true dynamic behavior. In this regard, questions regarding the need for considering the effect of frequency characteristics of input earthquake, natural period of the backfill soil and the subsoil underneath the wall, and wall height on the deformation of quay wall crown (<em>D<sub>h</sub></em>) have been explored. In this study, dynamic centrifuge tests were conducted using the gravity type quay wall models designed with a <em>k<sub>h</sub></em> value of 0.13 to assess the behavior of the model wall during earthquakes. Three different variables: input earthquake motions, wall heights and the thickness of subsoil underneath the wall were considered, and the test results were compared and analyzed to assess the validity of the conventional <em>k<sub>h</sub></em> concept under these conditions. In addition, some improvements that should be considered for the future revision of the <em>k<sub>h</sub></em> definition are discussed.</p>

scholarly journals Sistem Informasi Geografis (SIG) untuk Zonasi Daerah Bahaya Kerusakan Bangunan Akibat Gempa Bumi: Studi Kasus pada Kota Banda Aceh dan Sekitarnya

2012 ◽  
Vol 3 (1) ◽  
pp. 645
Author(s):  
Edy Irwansyah ◽  
Iqbal S. ◽  
M. Ikhsan ◽  
R. I Made Oka Yoga
Keyword(s):  
Peak Ground Acceleration ◽  
Design Method ◽  
Earthquake Hazard ◽  
Building Damage ◽  
Flow Diagram ◽  
Ground Acceleration ◽  
Analysis And Design ◽  
Entity Relationship Diagram ◽  
Surrounding Areas ◽  
Banda Aceh

This study aims to develop a geographic information system software that has the ability to develop hazard area zoning of building damage due to earthquake, especially in Banda Aceh and the surrounding areas using peak ground acceleration (PGA) value approach. Analysis and design methods are implemented in this study. The analytical method consists of two stages, namely seismic data collection period 1973 - 2011 by magnitude more than 5 on the Richter scale and the calculation of earthquake acceleration on bedrock using the attenuation function of Crouse. The design method comprises several structured stages, which are designing: data flow diagram (DFD), entity relationship diagram (ERD), menus, screens, and state transition diagrams (STD). The main conclusions of this study is that a GIS -based local zoning of earthquake hazard risk can be built and developed with calculation and classification approach of the peak ground acceleration (PGA). In addition, there is a relationship significant spatial found by comparing the results with the zoning patterns of building damage in the earthquake of 2004.

Analisis Percepatan Tanah Puncak Akibat Gempa Pada Kota Sorong Sebagai Upaya Mitigasi Bencana

2018 ◽  
Vol 4 (2) ◽  
pp. 14
Author(s):  
Imam Trianggoro Saputro ◽  
Mohammad Aris
Keyword(s):  
Peak Ground Acceleration ◽  
Ground Acceleration ◽  
Papua Barat

Sorong merupakan salah satu kota yang terletak di Provinsi Papua Barat. Daerah ini memiliki tingkat kerentanan yang tinggi terhadap ancaman bahaya gempa bumi karena lokasinya terletak di antara pertemuan lempengan tektonik dan beberapa sesar aktif. Tingkat kerawanan terhadap gempa pada daerah ini cukup tinggi. Pada September 2016, BMKG mencatat bahwa terjadi gempa bumi dengan skala magnitudo sebesar 6,8 SR (Skala Ritcher) dengan kedalaman 10 meter dari permukaan laut dan berjarak 31 km arah timur laut kota Sorong. Gempa ini bersifat merusak. Akibat gempa ini, sebanyak 62 orang terluka dan 257 rumah rusak. Untuk itu diperlukan suatu analisis terhadap percepatan tanah puncak (Peak Ground Acceleration) terbaru sebagai langkah mitigasi yang nantinya dapat digunakan untuk perencanaan gedung tahan gempa.Pengumpulan data gempa pada peneltian ini yaitu data gempa yang terjadi sekitar kota Sorong pada rentang waktu 1900-2017. Data gempa yang diambil adalah yang berpotensi merusak struktur yaitu dengan magnitudo (Mw) ≥ 5 dengan radius gempa 500 km dari kota Sorong dan memiliki kedalaman antara 0 - 300 km. Setelah diperoleh data gempa maka dibuat peta sebaran gempa di wilayah kota Sorong. Percepatan tanah puncak dihitung berdasarkan fungsi atenuasi matuscha (1980) dan menggunakan pendekatan metode Gumbel.Hasil penelitian menunjukkan bahwa nilai percepatan tanah puncak (PGA) di wilayah kota Sorong pada periode ulang 2500 tahun atau menggunakan probabilitas terlampaui 2% dalam 50 tahun umur rencana bangunan diperoleh sebesar 708.9520 cm/dt2 atau 0.7227 g. Apabila melihat peta gempa SNI 1726-2012 yang menggunakan probabilitas yang sama maka nilai percepatan tanah puncak (PGA) ketika gempa bumi berkisar antara 0.4 g - 0.6 g. Nilai ini mengalami peningkatan yang berarti tingkat resiko terhadap gempa bumi pada wilayah kota Sorong meningkat.

Implementing the performance-based seismic design for new reinforced concrete structures: Comparison among ASCE/SEI 41, TBI, and LATBSDC

2021 ◽  
pp. 875529302098196
Author(s):  
Siamak Sattar ◽  
Anne Hulsey ◽  
Garrett Hagen ◽  
Farzad Naeim ◽  
Steven McCabe
Keyword(s):  
Reinforced Concrete ◽  
Los Angeles ◽  
Seismic Design ◽  
Common Ground ◽  
Seismic Analysis ◽  
Tall Buildings ◽  
The United States ◽  
Analysis And Design ◽  
Performance Based Seismic Design ◽  
New Buildings

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.

A Geospatial Liquefaction Model for Rapid Response and Loss Estimation

2015 ◽  
Vol 31 (3) ◽  
pp. 1813-1837 ◽  
Author(s):  
Jing Zhu ◽  
Davene Daley ◽  
Laurie G. Baise ◽  
Eric M. Thompson ◽  
David J. Wald ◽  
...  
Keyword(s):  
Peak Ground Acceleration ◽  
Loss Estimation ◽  
Rapid Response ◽  
Ground Acceleration ◽  
Explanatory Variables ◽  
First Order ◽  
Database Development ◽  
Digital Elevation ◽  
Compound Topographic Index ◽  
Distance Parameter

We describe an approach to model liquefaction extent that focuses on identifying broadly available geospatial variables (e.g., derived from digital elevation models) and earthquake-specific parameters (e.g., peak ground acceleration, PGA). A key step is database development: We focus on the 1995 Kobe and 2010–2011 Christchurch earthquakes because the presence/absence of liquefaction has been mapped so that the database is unbiased with respect to the areal extent of liquefaction. We derive two liquefaction models with explanatory variables that include PGA, shear-wave velocity, compound topographic index, and a newly defined normalized distance parameter (distance to coast divided by the sum of distance to coast and distance to the basin inland edge). To check the portability/reliability of these models, we apply them to the 2010 Haiti earthquake. We conclude that these models provide first-order approximations of the extent of liquefaction, appropriate for use in rapid response, loss estimation, and simulations.

scholarly journals Characterization of the Highly Efficient Sucrose Isomerase from Pantoea dispersa UQ68J and Cloning of the Sucrose Isomerase Gene

2005 ◽  
Vol 71 (3) ◽  
pp. 1581-1590 ◽  
Author(s):  
Luguang Wu ◽  
Robert G. Birch
Keyword(s):  
Catalytic Efficiency ◽  
High Ratio ◽  
Enzyme Active Site ◽  
E Coli ◽  
Pantoea Dispersa ◽  
Temperature Ranges ◽  
Lower Ratio ◽  
High Sucrose ◽  
Sucrose Isomerase

ABSTRACT Sucrose isomerase (SI) genes from Pantoea dispersa UQ68J, Klebsiella planticola UQ14S, and Erwinia rhapontici WAC2928 were cloned and expressed in Escherichia coli. The predicted products of the UQ14S and WAC2928 genes were similar to known SIs. The UQ68J SI differed substantially, and it showed the highest isomaltulose-producing efficiency in E. coli cells. The purified recombinant WAC2928 SI was unstable, whereas purified UQ68J and UQ14S SIs were very stable. UQ68J SI activity was optimal at pH 5 and 30 to 35°C, and it produced a high ratio of isomaltulose to trehalulose (>22:1) across its pH and temperature ranges for activity (pH 4 to 7 and 20 to 50°C). In contrast, UQ14S SI showed optimal activity at pH 6 and 35°C and produced a lower ratio of isomaltulose to trehalulose (<8:1) across its pH and temperature ranges for activity. UQ68J SI had much higher catalytic efficiency; the Km was 39.9 mM, the V max was 638 U mg−1, and the K cat/Km was 1.79 × 104 M−1 s−1, compared to a Km of 76.0 mM, a V max of 423 U mg−1, and a K cat/Km of 0.62 × 104 M−1 s−1 for UQ14S SI. UQ68J SI also showed no apparent reverse reaction producing glucose, fructose, or trehalulose from isomaltulose. These properties of the P. dispersa UQ68J enzyme are exceptional among purified SIs, and they indicate likely differences in the mechanism at the enzyme active site. They may favor the production of isomaltulose as an inhibitor of competing microbes in high-sucrose environments, and they are likely to be highly beneficial for industrial production of isomaltulose.

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