scholarly journals ON THE POSSIBILITY OF ASSESSING SEISMIC HAZARD FOR OFFSHORE CONSTRUCTIONS ON THE CASPIAN SHELF BY CALCULATION METHODS

2020 ◽  
Vol 4(48) ◽  
pp. 21-35
Author(s):  
B.A. Trifonov ◽  
◽  
S.Yu. Milanovsky ◽  
I.A. Mindel ◽  
V.V. Nesinov ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Computational Methods ◽  
Caspian Sea ◽  
Oil And Gas ◽  
Spectral Composition ◽  
Seismic Hazard Assessment ◽  
Offshore Structures ◽  
Soil Conditions ◽  
Seismic Microzoning ◽  
Local Soil

In recent years the world has been actively developing oil and gas fields on the shelf, including in seismically active areas. On the seabed it is very difficult to carry out qualitative geological and geophysical studies and seismological observations in full, which are a part of seismic microzoning works. Programs for computational methods during seismic microzoning allow taking into account nonlinear soil properties. In the article the experience of studies on seismic microzoning (2012–2015) for the installation area of offshore structures on the shelf of the Middle Caspian Sea is considered. In conditions of absence of observations by bottom seismic stations the possibility of seismic hazard assessment by computational methods taking into account local soil conditions is shown. Thus the obtained values of seismic intensity are lower in comparison with the results of estimations by method of engineering and geological analogies and method of seismic rigidity. Maximal impacts from zones of possible earthquake sources most dangerous for Middle Caspian Sea have been taken into account by peculiarities of spectral composition of vibrations of ground bases in the form of reaction spectra.

scholarly journals Seismic hazard assessment for the underwater gas pipeline route in the water area of the Nevelskoy Strait

Vestnik MGTU ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 14-34
Author(s):  
S. A. Kovachev ◽  
A. A. Krylov
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Oil And Gas ◽  
Seismic Hazard Assessment ◽  
Gas Pipeline ◽  
Soil Conditions ◽  
Seismic Zoning ◽  
Seismic Effects ◽  
Seismic Microzoning ◽  
Pipeline Route

The presence of seismic threat multiplies the environmental hazard, especially for oil and gas production and transport facilities in water areas. Currently, there are no normative maps of general seismic zoning of the water areas of the inland and marginal seas of Russia, especially since there are practically no maps of detailed seismic zoning and seismic microzoning of even individual parts of the water areas. Taking into account the fact that intensive development of offshore oil and gas fields and the Northern Sea Route has begun, the development of such maps becomes a very urgent scientific and practical task. The seismic hazard assessment for the submerged crossing was carried out in 2008. The initial seismic effects were calculated using a probabilistic seismic hazard analysis based on five models of seismic zones and three types of models of attenuation of peak and spectral accelerations. The results of the performed calculations, including deaggregation, have shown that the initial seismicity of the area of the gas pipeline crossing route through the Nevelskoy Strait for a return period of 1,000 years is lower than indicated on the OSR-2016-B map, where the eastern end of the crossing route through the strait is characterized by the initial seismicity equal to 9 points. The soil conditions (seismic microzoning) have been taken into account by three different methods: the seismic rigidity method, the calculation method, and the method considering the thickness of Quaternary deposits. The present studies show that seismic effects vary along the pipeline route from the mainland to Sakhalin Island from 8.4 to 8.9 on the MSK-64 scale for the recurrence period of seismic shaking T = 1,000 years and from 9.3 to 9.7 points for T = 5,000 years.

Seismic Hazard Assessment and Numerical Modeling for Seismic Microzonation purpose of Dushanbe, Tajikistan

2020 ◽  
Author(s):  
Farkhod Hakimov ◽  
Hans-Balder Havenith ◽  
Anatoly Ischuk ◽  
Marco Pilz ◽  
Klaus Reicherter
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Urban Areas ◽  
Seismic Hazard Assessment ◽  
Seismic Microzonation ◽  
Soil Conditions ◽  
Seismic Action ◽  
City Area ◽  
Local Soil ◽  
Local Soil Conditions

<p>Seismic hazard assessment of urban areas is an important and extremely challenging task. It is so important because without the knowledge of the influence of local soil conditions and properties, of the changing layer thickness in urban areas, and without considering multiple possible scenario earthquakes for this territory, engineers do not have enough information on how to design and construct seismically safe buildings. The particular challenge of this task is due to the great uncertainty affecting the prediction of the spatially (and sometimes even temporally) changing seismic properties of soils with respect to urban development.<br>Dushanbe is the capital of Tajikistan, a mountainous country marked by high to very high seismic hazard. The reason for the high seismic hazard specifically near Dushanbe is related to its location between two fault systems: South Gissar fault and Ilek-Vaksh fault.  Estimation of the seismic hazard of the urban areas in Tajikistan is very important because they had developed in a very short time and many high buildings are being constructed now Existing seismic action estimations are based on the old approaches when the main factors of the local soil conditions only consider general engineering-geological features of the territory as well as macro-seismic observations data. An additional problem is the building code in Tajikistan; it uses the estimation of the ground motions in terms of the MSK-64 scale, but does not enough take into account the variety of the soil conditions in the Dushanbe city area. Existing seismic hazard estimation of the area of Tajikistan is based on the so-called “The map of general seismic zoning of the territory of Tajikistan”, that was produced in 1978 in terms of MSK-64 scale. The seismic microzonation map of the Dushanbe city area was made in 1975 in terms of MSK-64 scale as well and was based on the engineering-geological approach mostly. This map does not represent the highly variable soil conditions of the Dushanbe city area which are partly due to the anthropogenic influence of the large city. Therefore, earlier seismic zonation maps assigned an intensity of IX to most districts of the city. However, those previous studies did not sufficiently quantify the local effects of soils on the seismic hazard, mainly the macro-seismic conditions (the relative distance of districts to fault lines) were considered for the zonation. <br>This study describes and implements a number of new approaches to the evaluation of maximum seismic impact and site effect values. </p>

scholarly journals SEISMIC DAMAGE SCENARIOS IN KALAMATA (S. GREECE)

2017 ◽  
Vol 50 (3) ◽  
pp. 1495
Author(s):  
D. Kazantzidou-Firtinidou ◽  
I. Kassaras ◽  
A. Ganas ◽  
C. Tsimi ◽  
N. Sakellariou ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Fragility Curves ◽  
Site Amplification ◽  
Soil Conditions ◽  
Damage Scenarios ◽  
Local Soil ◽  
Protection Strategies ◽  
The Impact ◽  
The City

Damage scenarios are necessary tools for stakeholders, in order to prepare protection strategies and a total emergency post-earthquake plan. To this aim, four seismic hazard models were developed for the city of Kalamata, according to stochastic simulation of the ground motion, using site amplification functions derived from ambient noise HVSR measurements. The structural vulnerability of the city was assessed following an empirical macroseismic model, developed for the European urban environment (EMS-98). The impact of the vulnerability due to the seismic hazard potential is also investigated by means of synthetic response spectral ratios at 108 sites of the city. The expected damage grade per building block, is calculated by combining vulnerability with the respective seismic intensities, derived for the four seismic sources. The importance of the followed methodology for implementing microzonation studies is emphasized, since the expected influence of the ground motion amplification due to local soil conditions has been approximated in detail. Moreover, new fragility curves for the main structural types in Kalamata are proposed for each seismic scenario.

scholarly journals Seismic response of various sites of the territory of Kyiv to seismic loads

2021 ◽  
Vol 43 (5) ◽  
pp. 150-164
Author(s):  
O. V. Kendzera ◽  
Yu. V. Semenova
Keyword(s):  
Seismic Hazard ◽  
Seismic Response ◽  
Soil Layer ◽  
Maximum Amplitude ◽  
Design Parameters ◽  
Soil Conditions ◽  
Seismic Loads ◽  
Potential Hazard ◽  
Local Soil ◽  
Seismic Vibrations

The research presented in the work aims to assess the seismic response of three different taxonometric sites, identified by the method of engineering and geological analogies within the territory of Kyiv, to seismic loads with different spectral content and peak amplitude from 0.01 g to 0.06 g. Assessment of the influence of local soil conditions on the intensity of earthquakes is an important task of earthquake-resistant design and construction. The soil layer at the base of the study site acts as a filter on seismic vibrations. It amplifies or attenuates the amplitude of the seismic wave propagating from the bedrock to the free surface. The paper considers the mechanisms of the possible amplification of seismic motions by various soil complexes and methods for calculating the seismic response to seismic loads of various intensities. As an analytical tool for analyzing the response of the taxonometric areas to seismic vibrations (seismic response), an equivalent linear analysis was used, which is comprehensively studied and widely used in engineering seismology. For the selected sites, models of soil strata were built, and graphs of changes with depth of peak shear strain and peak ground acceleration (PGA) were calculated, as well as predicted (expected with a given probability of non-exceeding) amplitude Fourier spectra of seismic motions in the upper layer and the response spectra of single oscillators with 5 % attenuation to seismic effects with a maximum amplitude from 0.01 g to 0.06 g. A comparative analysis of the change in the value of these parameters in individual sections of Kyiv is presented. It is shown that to assess the potential hazard from seismic ground motions during earthquakes, it is necessary to use the maximum number of design parameters that characterize the seismic hazard of specific areas and which are used to determine the seismic resistance of buildings and structures. The most complete seismic hazard for calculating the seismic stability of objects is set by the full vector of seismic motions deployed in time: calculated accelerograms, seismograms and velocigrams. The presented calculation results are planned to be used in solving methodological and practical problems of earthquake protection, which can be realized in different parts of the territory of Kyiv.

scholarly journals Preface

2021 ◽  
Vol 1201 (1) ◽  
pp. 011001
Keyword(s):  
Computational Methods ◽  
Structural Engineering ◽  
Oil And Gas ◽  
Materials Science ◽  
Mechanical Systems ◽  
Offshore Structures ◽  
Technical Committee ◽  
The Arctic ◽  
Topic Area ◽  
Joint Event

Third Conference of Computational Methods & Ocean Technology and Second Conference of Oil and Gas Technology (COTech & OGTech 2021) November 25 - 27, 2021, University of Stavanger, Stavanger, Norway and Russian State Gubkin University of Oil and Gas, Moscow, Russia This conference is organized as a joint event of the COTech (Computational Methods & Ocean Technology) and OGTech (Oil and Gas Technology) conferences. The COTech conference started as part of the research and dissemination activities of the Program Area for research "COTech - Computational methods in Offshore Technology" at Faculty of Science and Technology, University of Stavanger (UiS). This Program Area for Research was founded in 2015 with seven professors, four associate professors, two adjunct professors and five research (PhD) students from the Department of Mechanical and Structural Engineering and Materials Science (IMBM), whose expertise and competence lies primarily within use of computational methods such as finite element methods, boundary and volume element methods, computational fluid dynamics and the like in marine and subsea technology, marine operations, design and analysis of mechanical systems, integrity and reliability of offshore structures and mechanical systems, renewable energy and wind engineering. In the ocean-related engineering area in particular, numerical computation approach is nowadays not only serving as a means to cultivate and realize innovative ideas, but also it is becoming the primary choice to solve complex engineering problems for the harsh and unfriendly environment in the Arctic. List of Conference Organizing Committee, Topic Area Coordinators and Track Chairs, Invited Keynote Speakers, Technical Committee Members and Reviewers are available in this pdf.

Up-to-Date of Seismic Design Spectrum for Offshore Platforms at the Bay of Campeche

2003 ◽  
Author(s):  
Joel A. Garci´a Vargas ◽  
Roberto Pe´rez Marti´nez
Keyword(s):  
Seismic Hazard ◽  
Seismic Design ◽  
Soil Conditions ◽  
Reserve Capacity ◽  
Seismic Action ◽  
Offshore Platforms ◽  
Local Conditions ◽  
Design Spectrum ◽  
Earthquake Sources ◽  
Local Soil

This paper presents the procedure proposed by the ISO code adapted to the local conditions in the Bay of Campeche, Mexico in order to obtain design spectrum for different seismic reserve capacity factors. A probabilistic seismic hazard analyses is used in order to determine the uniform hazard spectrum where the seismic environment, according to previous researches, is influenced by three primary types of earthquake sources: the subduction zone on the western pacific coast of Mexico, the lithospheric slab within the central portion of Mexico and the trans-mexican volcanic belt. This earthquake spatial distribution can be shown trough the historic catalog of earthquake occurrences during the period 1900–2001 used. On the one hand, in the evaluation of the characteristics and the uncertainties associated with the earthquake sources and their effects on the interest sites, are taken into account the characterization of the earthquake sources, the effect of the seismic wave propagation, the local conditions and the soil-structure interaction developed during earthquake ground motions. On the other hand, the uncertainties on the seismic hazard curve and those associated with the platform behavior (mass, stiffness, damping) in which their values are assigned to be consistent with the ISO 19901-2 and ISO 19902 seismic code suggestions. The final result consists in a seismic design spectrum for offshore platforms at the Bay of Campeche, which are consistent with the recommended ISO 19902 seismic reserve capacity factors, modified for local soil conditions, following a detailed seismic-action procedure.

Sign in / Sign up

Export Citation Format

Share Document