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1

Experimental study on seismic behaviour of fully bolted concrete shear walls

Ding Tao, Shen Kaige, Tan Ding, Zhao Yong

Archives of Civil and Mechanical Engineering

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2023

|

Vol. 23, no. 3

art. no. e142

EN

Bolted precast concrete shear wall structures have the potential to be disassembled and exhibit superior seismic performance. In this study, a new type of fully bolted concrete shear wall was proposed, and its seismic behaviour was examined through cyclic loading tests. The influence of the connecting method, axial compression ratio, and interface roughness on the seismic behaviour of this fully bolted concrete shear wall was analysed, and the design method was proposed. The results showed that at the axial compression ratio of 0.05, the proposed new type of fully bolted concrete shear wall structure behaved favourable seismic performance and the energy dissipation capacity was improved about 26%. Moreover, the proposed formulas used for the calculation of the bearing capacity of this connection provide a basis for the application of the fully bolted concrete shear walls.

2

Performance study of precast reinforced concrete shear walls with steel columns containing friction-bearing devices

Fang Qiang, Qiu Hongxing, Sun Jian, Dal Lago Bruno, Jiang Hongbo

Archives of Civil and Mechanical Engineering

|

2021

|

Vol. 21, no. 3

439--457

EN

A novel structural system based on precast reinforced concrete (RC) shear wall panels mutually connected vertically using T-connectors and horizontally using friction-bearing devices (FBDs) mounted on interposed steel columns was recently proposed. To investigate the seismic performance of the proposed precast RC shear wall system, three subassembly specimens simulating a single construction modulus were constructed and tested by considering different slot length and numbers of FBDs under quasi-static cyclic loading. Ductile flexural failure at drift of around 4.2% and load of around 265 kN was attained for both specimens with long-slot FBDs, while shear failure after moderate flexural ductility was attained at drift of around 3.8% and higher load of around 368.3 kN for specimens with short-slot FBDs, showing not-direct dependence of the load capacity on the number of FBDs installed. However, the higher number of FBDs allowed for higher hysteretic damping with a 27.3% increase in dissipated energy through cycles.

3

Mitigating the seismic pounding of multi-story buildings in series using linear and nonlinear fluid viscous dampers

Elwardany Hytham, Jankowski Robert, Seleemah Ayman

Archives of Civil and Mechanical Engineering

|

2021

|

Vol. 21, no. 4

1--16

EN

Seismic-induced pounding between adjacent buildings may have serious consequences, ranging from minor damage up to total collapse. Therefore, researchers try to mitigate the pounding problem using different methods, such as coupling the adjacent buildings with stiff beams, connecting them using viscoelastic links, and installing damping devices in each building individually. In the current paper, the effect of using linear and nonlinear fluid viscous dampers to mitigate the mutual pounding between a series of structures is investigated. Nonlinear finite-element analysis of a series of adjacent steel buildings equipped with damping devices was conducted. Contact surfaces with both contactor and target were used to model the mutual pounding. The results indicate that the use of linear or nonlinear dampers leads to the significant reduction in the response of adjacent buildings in series. Moreover, the substantial improvement of the performance of buildings has been observed for almost all stories. From the design point of view, it is concluded that dampers implemented in adjacent buildings should be designed to resist maximum force of 6.20 or 1.90 times the design independent force in the case of using linear or nonlinear fluid viscous dampers, respectively. Also, designers should pay attention to the design of the structural elements surrounding dampers, because considerable forces due to pounding may occur in the dampers at the maximum displaced position of the structure.

4

Experimental study on seismic performance of ultrahigh-strength steel frames with buckling-restrained braces

Pei Sheng, Zhang Zhe, Deng En-Feng, Wang Yan-Bo

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 4

493--506

EN

The application of high-strength steel (HSS) is a significant trend in the development of steel structures. Two main challenges for HSS structures in seismic design (i.e., low energy dissipation capacity and low lateral stiffness) need to be addressed before HSS structures can be widely constructed in practice. To solve those problems, the seismic performance of structures combined of HSS frames and concentric buckling-restrained braces (BRBs) was investigated in this study. Two half-scale experimental specimens with different stiffness ratios between BRB and HSS frame were fabricated and tested under constant vertical load and cyclic increasing horizontal load. The hysteretic response, horizontal bearing capacity, internal force distribution, energy dissipation capacity, and ductility of the dual system were analyzed. The results showed that the specimens exhibited overall ductile performance with high elastic stiffness, significant ductility, and excellent energy dissipation capacity. The characteristics of both specimens in the pseudo-static test can be divided into three typical phases, which were described as overall elastic phase, BRB hardening phase, and failing phase. The BRB hardening phase was characterized by high energy dissipation capacity, and the plastic deformation was limited to the BRB, so the ductile demand of HSS member in HSSF-BRB was reduced. Moreover, the effect of stiffness ratio between BRB and HSS frame on seismic performance was discussed in this paper.

5

Experimental and numerical investigation on non-welding CFDST joint for seismic evaluation of moment resisting frame

Guo Lei, Wang Jingfeng, Wang Wanqian, Liu Yong

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 2

128--145

EN

This paper aims to evaluate the seismic performance of concrete filled double-skin steel tubular (CFDST) frame structures. An experimental investigation on internal joints to CFDST columns was conducted to assess their seismic behavior, in which non-welding connection method was employed to avoid possible premature welding fracture. Experimental results declared that this type of joint behaved in a semi-rigid manner. Numerical models were then established to simulate the seismic performance of the joints. The moment–rotation relationship and shear behavior of panel zone were both accounted according to the component method and strut model, respectively. Subsequently, a CFDST moment resisting frame with non-welding connections (NWF) was numerically analyzed to detect its seismic response under design-based and maximum considered earthquakes. The numerical results confirmed that the NWF could lower the seismic response in terms of base shear force and joint moment compared with namely rigid frame (NRF). It also verified that the maximum story drift ratios of the NWF were higher than those of the NWF. Increment dynamic analyses (IDA) were also performed to evaluate the collapse behavior. Furthermore, a detailed discussion was conducted to analyze the influence of joint stiffness on global behavior of the NWF. The analytical results verified that this type of NWF had satisfied seismic behavior and excellent anti-collapse performance. More importantly, the NWF could conveniently adjust the stiffness of each story by varying the stiffness of the non-welding connection to decrease the story drift and to achieve a uniform story drift distribution.

6

Seismic Behavior of Earth Dams With Different Reservoir Water Levels Under Near-Field and Far-Field Earthquakes

Asadi Masoud, Soltani Fazlollah, Sinvandi-Pour Abbas, Noroozinejad Farsangi Ehsan

Civil and Environmental Engineering Reports

|

2020

|

Vol. 30, no. 4

125--141

EN

The height of reservoir water is one of the important factors affecting the seismic behaviour of earth dams. A large number of earth dams have been constructed in different countries that are sometimes located in a high-risk geographical zone. The studies on the seismic behaviour of earth dams have been conducted for several decades. However, this study, considering the importance of the subject, it investigates the seismic behaviour of Sumbar rock-fill embankment dam under near- and far-field earthquakes with variation in the water level behind the dam. The ratio of water height of the dam to dam height is considered as an important indicator to investigate the seismic performance of these structures. The analyses were performed using the ABAQUS finite element platform, under 7 near-field and 7 far-field earthquake records. In this research, the changes in dam stresses, displacements, and failure of the dam have been discussed. The results indicated that the effect of near-field earthquakes on the seismic behaviour of earth dams is more significant than far-field earthquakes.

7

Seismic behaviour of cross-shaped steel fibre reinforced concrete columns

Sun Linzhu, Wei Zhengzhen, Li Wei, Xiang Jinhuai

Archives of Civil and Mechanical Engineering

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2020

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Vol. 20, no. 4

418--436

EN

This paper proposes a novel cross-shaped column in which steel fibre reinforced concrete (SFRC) is integrated with a high-strength stirrup to enhance its seismic behaviour. An experimental investigation was conducted on eight cross-shaped column specimens subjected to cyclic lateral loading. All of the specimens were evaluated in terms of their cracking patterns, failure modes, hysteresis behaviour, deformation and ductility, strength and stiffness degradation, and energy dissipation performance. The effects of the stirrup strength, stirrup spacing, steel fibre content, and axial load ratio were investigated. The experimental results demonstrated that all of the specimens exhibited flexural failure. The cracked concrete of the specimens with steel fibres could be prevented from spalling. The hysteresis loops of all of the specimens were relatively full without a readily observable pinching phenomenon and the specimens possessed a satisfactory energy dissipation capacity. Compared with the normal specimens, the specimens with high-strength stirrups, close stirrup spacing, and steel fibre exhibited a higher energy dissipation capacity, lateral bearing capacity, displacement ductility, and initial stiffness. However, the ductility rapidly decreased as the axial load ratio increased. Additionally, neither the incorporation of steel fibre nor the reduction of the stirrup spacing or the axial load ratio substantially mitigated the stiffness degradation. Based on the test results, calculation models were proposed for calculating the seismic bending moment capacities of the specimens. The calculated values were in accordance with the test results.

8

Novel wide-angle AVO attributes using rational function

Xue Yaru, Xiang Jialin, Xu Xin

Acta Geophysica

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2020

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Vol. 68, no. 1

123--132

EN

Conventional AVO inversion employs Zoeppritz equations and various approximations to them to obtain the refection coeffcients of plane-waves, which are confned to a certain (small) angle range (mostly below 40°). However, near the critical angles (wide-angle), refections at the post-critical angles provide much more potential for velocity and density inversion because of the large amplitudes and phases-shifted waveforms, while the Zoeppritz equations are not applicable anymore. Hence, there is a strong demand for the research into wide-angle AVO. With refection coefcients at wide-angle corresponding to the features of rational function, we try to approximate the seismic data with vector ftting which is used to obtain the rational zero-pole and residual properties of wide-angle AVO. We apply this technique to classify AVO type and recognize the lithology. Our experiment shows that extending our research into wide-angle AVO is very promising in gathering richer data for a more accurate seismic analysis.

9

Tram type influence on the frequency spectrum character of the subsoil dynamic response

Stolarik M., Pinka M., Nedoma J., Fajkus M., Martinek R.

Przegląd Elektrotechniczny

|

2018

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R. 94, nr 11

96--100

EN

This article deals with the results of the experimental seismic measurement using a standard seismic in situ station on a rock mass where the influence of the type of the trams passing on the frequency spectrum characteristics, the bandwidth and the maximum peaks was monitored. The goal of presented experimental measurement was to verify whether it is possible to find common patterns for individual types of tram cars in the frequency spectra using standard equipment for seismic measurements. The results show that in the spectrums certain characteristics can be traced, which are common to both a particular type of tram and a common group of tram types historically or structurally derived from each other.

PL

W artykule przedstawiono badania sejsmiczne związane z przejazdem różnych typów tramwajów. Przedstawiono charakterystyki widmowe oraz monitorowano pasmo częstotliwości. Ekspeyment wykazał że każdy z pojazdów jak również każdy typ pojazdu ma typową dla siebie charakterystykę sejsmiczną.

10

Simplified reliability analysis of multi hazard risk in gravity dams via machine learning techniques

Hariri-Ardebili M. A., Pourkamali-Anaraki F.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 2

592--610

EN

Deterministic analysis does not provide a comprehensive model for concrete dam response under multi-hazard risk. Thus, the use of probabilistic approach is usually recommended which is problematic due to high computational demand. This paper presents a simplified reliability analysis framework for gravity dams subjected to flooding, earthquakes, and aging. A group of time-variant degradation models are proposed for different random variables. Response of the dam is presented by explicit limit state functions. The probability of failure is directly computed by either classical Monte Carlo simulation or the refined importance sampling technique. Next, three machine learning techniques (i.e., K-nearest neighbor, support vector machine, and naive Bayes classifier) are adopted for binary classification of the structural results. These methods are then demonstrated in terms of accuracy, applicability and computational time for prediction of the failure probability. Results are then generalized for different dam classes (based on the height-to-width ratio), various water levels, earthquake intensity, degradation rate, and cross-correlation between the random variables. Finally, a sigmoid-type function is proposed for analytical calculation of the failure probability for different classes of gravity dams. This function is then specialized for the hydrological hazard and the failure surface is presented as a direct function of the dam's height and width.

11

Reliability-based dynamical design of a singular structure for high energy physics experiments

Palma R., Torrent J., Pérez-Aparicio J. L., Ripoll L.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 1

256--266

EN

The present work presents a comprehensive design and dynamic calculation of singular metallic structures, part of the Neutrino Experiment NEXT. The experiment uses an electroluminescent TPC chamber, a high-pressure 136Xe gas vessel enclosing the detector. A lead-block “castle” or containing box shields this vessel against external γ-rays from all directions; in spite of its heavy weight, the castle must be regularly open for the detector maintenance. Since the structures will be constructed at a middle-level seismic localization (Laboratorio Subterráneo Canfranc, Spain), the earthquake hazard must be taken into account. Vessel and castle are supported by a rigid frame, which must satisfy two requirements: (i) the Spanish seismic standard, (ii) for equipment protection, the detector maximum horizontal acceleration must be <1 [m/s2]. This frame rests on special base isolators to decrease horizontal accelerations in case of an earthquake. Three dynamical calculations are conducted: (i) a response spectrum analysis to comply with the standard, (ii) five time-history analyses to calculate tolerances and, (iii) a reliability-based approach using 1000 time-history responses to ensure satisfaction of the operating requirements. The final outcome is the design of a singular structure optimized for the NEXT experiment with a probability of failure against any standard earthquake of only 0.125%.

12

Cyclic testing of steel frames infilled with concrete sandwich panels

Hashemi S. J., Razzaghi J., Moghadam A. S., Lourenço P. B.

Archives of Civil and Mechanical Engineering

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2018

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Vol. 18, no. 2

557--572

EN

In-plane seismic behaviour of concrete sandwich panel-infilled steel frame (CSP-ISF) was experimentally and numerically investigated. Four large-scale, single bay and single story steel frame specimens were tested under reversed cyclic lateral loading. Three infilled frames with different aspect ratios along with one bare frame were considered. It was found that addition of sandwich panels leads to considerable increase in the lateral stiffness and strength, ductility, energy dissipation capacity as well as equivalent viscous damping ratio of the steel frames. Furthermore, the maximum shear capacity of CSP-ISF specimens was validated by analytical approaches which showed good agreement with experimental results. Based on the present experiments, structural performance levels required for Performance-based Analysis are also proposed for concrete sandwich panel used as infill walls. Finally, a numerical model is presented to analyze the nonlinear behaviour of CSP-ISFs.

13

Geological and seismic investigation of former lignite mining area in Zielona Góra – two case studies

Gontaszewska-Piekarz A., Kłosiński J.

Czasopismo Inżynierii Lądowej, Środowiska i Architektury / Journal of Civil Engineering, Environment and Architecture

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2017

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z. 64, nr 2/I

311--326

EN

The article presents two case studies of investigation carried out on plots of land, intended for multi-family residential development, lying on a former lignite mining area in Zielona Gora. It was underground mining, operating in the years 1840- 1948. Lignite deposits were extracted with the room and pillar method, i.e. with an overlayer collapse, causing deformations on the surface of the ground. In the first case study, there was no detailed mining data. In order to identify the geological structure under the planned seven-floor multi-family building, seismic surveys were performed with the technique of multichannel analysis of surface waves (MASW). Three seismic profiles were performed. They revealed the presence of several zones where S-waves had smaller velocity values. In order to verify whether the zones with the smaller values of velocity correspond to e.g. lower soil density resulting from collapsed exploitation room, some drillings were undertaken to the depth indicated in geophysical investigation. Additionally, the CPT and dynamic probing were also performed. The data obtained allowed to determine the soil parameters necessary for the safe design and foundation of the building. In the second case study, a historical mining map with the marked location of the shaft and the main galleries was used. Formerly, geological and engineering documentation for construction works had been prepared, based on 30-meter drillings and soundings with a heavy probe. The mining maps and the contemporary maps were mapped one on another carefully and accurately, calibrated with historic buildings. Thus, the accuracy of 5 m was obtained. Additionally, investigation with the MASW technique was performed. Ten seismic profiles were performed, and then verified by drillings. Also, dynamic probing in the vicinity of the expected location of the shaft was performed. Neither the MASW investigation nor the dynamic probing did not reveal any alterations in the soil condition, which would suggest the presence of the properly liquidated shaft. Thus, based exclusively on the cartographic material, the area comprising the liquidated and backfilled shaft was established. The area was excluded from the plans for the intended building erection.

PL

Artykuł przedstawia badania, jakie przeprowadzono na dwóch przykładowych działkach przeznaczonych dla zabudowy wielorodzinnej leżących na terenie dawnego górnictwa węgla brunatnego w Zielonej Górze. Było to górnictwo podziemne, działające w latach 1840-1948. Węgiel 326 A. Gontaszewska-Piekarz, J. Kłosiński brunatny eksploatowany był metodą filarowo – komorową, na zawał, powodując powstawania na powierzchni deformacji terenu. Dla niektórych fragmentów miasta zachowały się mapy górnicze. W pierwszym przypadku brak było szczegółowych danych górniczych. W celu rozpoznania budowy geologicznej pod projektowany budynek wielorodzinny, 7-kondygnacyjny wykonano geofizyczne badania sejsmiczne techniką wielokanałowej analizy fal powierzchniowych MASW. Wykonano 3 profile sejsmiczne. Wykazały one kilka niewielkich stref cechujących się niższymi wartościami prędkości fal sejsmicznych poprzecznych S. W celu weryfikacji, czy strefy obniżeń prędkości związane są np. z obniżonym zagęszczeniem gruntu wskutek zawału stropu nad komorami eksploatacyjnymi wykonano odwierty do głębokości wskazanej badaniami geofizycznymi. Wykonano także sondowania sondą CPTu oraz sondowania dynamiczne. Uzyskane dane pozwoliły na określenie parametrów podłoża koniecznych do bezpiecznego zaprojektowania posadowienia budynku. W drugim przypadku dostępna była mapa górnicza z lokalizacją szybu oraz głównych chodników.

14

Wpływ ruchów zapadliskowych powierzchni Ziemi na niestabilność strefy brzegowej Morza Bałtyckiego

Kaszubowski L. J., Coufal R.

Inżynieria Morska i Geotechnika

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2016

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nr 3

135--145

PL

Zastosowanie badań sejsmicznych o wysokiej rozdzielczości w rozpoznaniu wpływu ruchów zapadliskowych powierzchni Ziemi na niestabilność strefy brzegowej Morza Bałtyckiego. Badania przeprowadzone z wykorzystaniem metody fal odbitych. Przykłady badań sejsmicznych na obszarze polskiej strefy brzegowej wykazujących występowanie ruchów zapadliskowych powierzchni Ziemi. Wnioski wynikające z tych przykładów.

EN

The use of high resolution seismic research to recognize the influence of the cave movements the Earth’s surface on the instability of the coastal zone of the Baltic Sea. The research carried out using reflection waves method. Examples of seismic research in the area of the Polish coastal zone showing the existence of cave movements of the Earth’s surface. Conclusions of the examples.

15

Badania sejsmiczne struktury wałów przeciwpowodziowych

Kaszubowski L. J.

Inżynieria Morska i Geotechnika

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2015

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nr 1

17--22

PL

Badania sejsmiczne o wysokiej rozdzielczości wałów przeciwpowodziowych Zakładów Chemicznych Police. Prześledzenie struktury wałów przeciwpowodziowych i ich podłoża, w celu wykrycia najsłabszych miejsc w strukturze wałów, gdzie występują grunty nasypowe o najsłabszych parametrach geotechnicznych.

EN

The results of research of high-resolution seismic investigations on the area of the Police Chemical Plants. Investigation of the structure of the flood embankments and their substrate for detection of the most vulnerable places in the structure of the flood embankments, where are occurring the soils, which have the most vulnerable geotechnical parameters.

16

Wpływ współczesnych ruchów pionowych podłoża na niestabilność infrastruktury budowlano-drogowej

Kaszubowski L. J.

Przegląd Geologiczny

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2014

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Vol. 62, nr 10/2

601--608

EN

The author presents the results of the engineering-geological research carried out along of the Potulicka St. and Bohaterów Warszawy Ave. in Szczecin. The analysis relates to geological drillings and made soundings carried out using an SL and ZW. Additionally, author presents use of high resolution seismic research as example to recognize the influence of the present-day vertical movements the ground surface, which have a significant effect on the instability of many parts of the existing technical infrastructure. Seismic high-resolution research carried out by the aid of apparatus CS-5G-1, where the reflection method was used. In the field research, used range Z = 50 ms, allowing the penetration of seismic waves in the Quaternary deposits to a depth of 40 m below terraine level. Author presents example of seismic research in the area of flood embankments of the Chemical Plants in Police (Western Pomerania), which show the existence of present-day vertical movements of the ground surface and which of similar size and in the same way can have a real impact in many areas on the instability of the existing civil engineering infrastructure, and can contribute to serious accidents or even disasters. As shown of the engineering-geological research in the area of Potulicka Street and Bohaterów Warszawy Avenue in Szczecin and seismic investigations, contemporary vertical movements in the Western Pomerania have different average rate of displacement of geological layers from 5–10 mm / year.

17

On the interpretation of seismic cone penetration test (SCPT) results

Bagińska I., Janecki W., Sobótka M.

Studia Geotechnica et Mechanica

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2013

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Vol. 35, nr 4

3--11

EN

The paper deals with the methodology of performing and interpretation of seismic cone penetration test (SCPT). This type of test is used to determine velocity of the seismic wave in the soil medium. This study is focused on shear wave. The wave is triggered on the ground surface by hitting an anvil with a sledgehammer. Then, vibrations induced at different depths are measured. Based on recorded measurements wave velocity (Vs) and thus also small strain shear modulus Gmax may be calculated. An interpretation of exemplary seismic test results is presented. Crossover and cross-correlation methods are discussed and another, more adequate one is featured and then applied in the interpretation example. Conditions for correct test performance and interpretation are discussed.

18

Rola powierzchniowych badań sejsmicznych i pomiarów PPS w poszukiwaniach niekonwencjonalnych złóż węglowodorów typu shale-gas

Bartoń R.

Wiadomości Naftowe i Gazownicze

|

2012

|

R. 15, Nr 10 (174)

4--6

PL

Prawidłowe odwzorowanie rozmieszczenia oraz zachowania się szczelin w utworach łupkowych, przy wiernym opisie własności geomechanicznego ośrodka geologicznego, wymaga wykonania analiz i interpretacji na danych sejsmicznych z uwzględnieniem anizotropii. Azymutalne i wieloskładnikowe pomiary pionowego profilowania sejsmicznego PPS 3C są najbardziej użytecznym narzędziem, spośród stosowanych metod sejsmicznych, do badania anizotropii ośrodka geologicznego. Analizy prędkościowe oraz polaryzacyjne azymutalnych wieloskładnikowych pól falowych PPS 3C są podstawą do określania kierunków oraz ilościowej oceny anizotropii. Przetwarzanie danych sejsmicznych w oparciu o azymutalne śledzenie zmian prędkości oraz AVO, w połączeniu z geomechanicznymi własnościami skał, obliczonymi dla ośrodków izotropowych, może być użyte do predykcji in-situ naprężeń, występujących w zbiornikach łupkowych. Poprawne wyznaczenie oraz zorientowanie naprężeń, umożliwia określenie głównych kierunków szczelin w strefie złożowej i pozwala na optymalne zaprojektowanie usytuowania otworów poziomych.

EN

Correct imaging of distribution and behavior of cracks in shales formation, with a faithful description of the geomechanical properties of the geological medium, requires the analysis and interpretation of seismic data, taking into account the anisotropy. Multi-offset and multi-component Vertical Seismic Profiling VSP 3C measurements are most useful tool, from among current seismic methods, to investigation of the anisotropy of geological medium. Velocity and polarization analyses of multi-azimuth and multi-component wave fields of VSP 3C are base to defining of directions and quantitative estimation of the anisotropy. Processing of seismic data based on the azimuth tracking in velocity and AVO changes, in combination with geomechanical properties of rocks, calculated for isotropic medium, can be used for prediction of in-situ stresses, occurring in shale reservoirs. Correct determination and orientation of the stress, allows to define the main directions of cracks in the reservoir zone and allows too for optimal design location of horizontal wells.

19

Badania struktury skorupy ziemskiej na obszarze Europy Centralnej, ze szczególnym uwzględnieniem Transeuropejskiej Strefy Szwu, metodami głębokich profilowań sejsmicznych

Guterch A.

Wiadomości Naftowe i Gazownicze

|

2012

|

R. 15, Nr 9 (173)

4--9

EN

The complex tectonic history of Central Europe (Fig. 1a) reflects the break-up of a Neoproterozoic supercontinet(s) (Rodinia/Pannotia) to form the fragment Baltica and the subsequent growth of continental Europe beginning with the Caledonian orogeny. Caledonian and younger Variscan orogenesis involved accretion of Laurentian and Gondwanan terranes to the riftet margin of Baltica. (East European craton, EEC) during the Paleozoic. From Central Poland northward, the region also experienced volcanic activity during the Permian and tectonic inversion during the Alpine orogeny, which in the south continues today. The Trans-European Suture Zone (TESZ) is a term used to refer to the suite of sutures and terranes that formed adjacent to the rifted margin of Baltica, and these features extend from the British Isles to the Black Sea region (Fig. 1a and 2). Understanding the structure and evolution of the TESZ region is one of the key tectonic challenges in Europe north of the Alps. The TESZ is far more complex than a single suture but in a broad sense is the boundary between the accreted terranes and Baltica. The TESZ includes the Teisseyre-Tornquist Zone (TTZ), which has several definitions. Here, we will use the term TTZ to refer to a structural zone associated with the southwestern edge of the EEC. Beginning in 1997, Central Europe, between the Baltic and Adriatic Seas, has been covered by an unprecedented network of seismic refraction experiments (Fig. 1b). These experiments - POLONAISE’97, CELEBRATION 2000, ALP 2002, and SUDETES 2003 - have only be possible due to a massive international cooperative effort. International Consortium consisted of 35 institutions from 16 countries in Europe and North America - Austria, Belarus, Canada, Croatia, Czech Republic, Denmark, Finland, Germany, Hungary, Lithuania, Poland, Russia, Slovakia, Slovenia, Turkey and the United States. The majority of the recording instruments was provided by the IRIS/ PASCAL Instrument Center and the University of Texas at El Paso (USA), the Geological Survey of Canada and other countries. For example, in the CELEBRATION experiment, the total number was 1230 stations ands 147 shot points located along seismic lines of a total length of about 9000 km. A large number of seismic sources and stations in all experiments means that besides 2 - D approach along profiles (Fig. 3 and 4), also 3 - D approach (Fig. 5 and 6) could be implemented in data interpretation. Total length of seismic profiles in all experiments is about 20 000 km (Fig. 1b).

20

Rola badań sejsmicznych i pomiarów PPS w poszukiwaniach niekonwencjonalnych złóż węglowodorów typu shale gas

Bartoń R.

Prace Naukowe Instytutu Nafty i Gazu

|

2012

|

nr 182 wyd. konferencyjne

263--268

PL

Prawidłowe odwzorowanie rozmieszczenia oraz zachowania się szczelin w utworach łupkowych, przy wiernym opisie własności geomechanicznego ośrodka geologicznego, wymaga wykonania analiz i interpretacji na danych sejsmicznych z uwzględnieniem anizotropii. Azymutalne i wieloskładnikowe pomiary pionowego profilowania sejsmicznego PPS 3C są najbardziej użytecznym narzędziem, spośród aktualnych metod sejsmicznych, do badania anizotropii ośrodka geologicznego. Analizy prędkościowe oraz polaryzacyjne azymutalnych wieloskładnikowych pól falowych PPS 3C są podstawą do określania kierunków oraz ilościowej oceny anizotropii. Przetwarzanie danych sejsmicznych, w oparciu o azymutalne śledzenie zmian prędkości oraz AVO, w połączeniu z geomechanicznymi własnościami skał obliczonymi dla ośrodków izotropowych, może być użyte do predykcji in situ naprężeń występujących w zbiornikach łupkowych. Poprawne wyznaczenie oraz zorientowanie naprężeń umożliwia określenie głównych kierunków szczelin w strefie złożowej i pozwala na optymalne zaprojektowanie usytuowania otworów poziomych.

EN

Correct imaging of distribution and behavior of cracks in shales formation, with a faithful description of the geomechanical properties of the geological medium, requires the analysis and interpretation of seismic data, taking into account the anisotropy. Multi-offset and multi-component Vertical Seismic Profiling VSP 3C measurements are most useful tool, from among current seismic methods, to investigation of the anisotropy of geological medium. Velocity and polarization analyses of multi-azimuth and multi-component wave fields of VSP 3C are base to defining directions and quantitative estimation of the anisotropy. Processing of seismic data based on the azimuth tracking in velocity and AVO changes, in combination with geomechanical properties of rocks, calculated for isotropic medium, can be used for prediction of in situ stresses, occurring in shale reservoirs. Correct determination and orientation of the stress allows to define the main directions of cracks in the reservoir zone and allows too for optimal design location of horizontal wells.