Wyniki wyszukiwania - BazTech

1

Spatial analysis of b-value variability in Elazig city and the surrounding area (Eastern Turkey)

Polat Gulten

Acta Geophysica

|

2022

|

Vol. 70, no 1

15--25

EN

Frequency-magnitude distribution was investigated in Elazig city and the surrounding area (coordinates ranging from 38.1° N to 39° N for latitudes and 39° E to 40° E for longitude) to reveal the present-day crustal stress within the region. For this study, a complete set of 5603 earthquakes of Md≥1 from 1 January 2000 to 31 August 2020 were localized from the Bogazici University, Kandilli Observatory and Earthquake Research Institute, Regional Earthquake-Tsunami Monitoring Center (KOERI) catalogue. For the whole study region, spatial mapping of the frequency-magnitude distribution was thus produced. The frequency-magnitude distribution (b-value) for seismicity within the study area was not homogeneous. Outstanding variations in the b-value were detected with b ranging from b≈slightly more than 0.3–2. In this region, low b-values are mostly dominant in the region except for a few local areas. This study also shows that accumulated stresses are high particularly at the Pütürge segment in contrast to the fault drawn in the south, which represents the main thrust belt that runs through Hani-Lice and stretches to Çüngüş. As expected, stress accumulation in reverse faults is fairly higher. However, the sharing of the tension formed in the compression zone of the Arabian Plate and the Anatolian plate (i.e. stress partitioning in a sense), results in a low share in the reverse fault belt.

2

Effects of horizontal ground motion incident angle on the seismic risk assessment of a high-speed railway continuous bridge

Wei Biao, Hu Zhangliang, Zuo Chengjun, Wang Weihao, Jiang Lizhong

Archives of Civil and Mechanical Engineering

|

2021

|

Vol. 21, no. 1

304--323

EN

This study investigates the effects of horizontal ground motion incident angle on a high-speed railway continuous bridge (HSRCB). To that end, incremental dynamic analyses (IDA), seismic vulnerability analyses and seismic risk assessments were conducted on a three-span HSRCB subjected to a set of ground motions under five incidence angles θ (0°–90°). The analysis was developed only from the perspective of PGA and the results showed that the longitudinal waves (θ = 0°) only caused seismic responses in the longitudinal direction, while the waves in other directions, especially in the transverse direction, caused a coupling response both in longitudinal and transverse directions for some components, such as the sliding layer and CA mortar layer. The longitudinal seismic damage of the sliding layer and CA mortar layer under the transverse waves should receive more attention in seismic design since the exceeding probabilities and seismic risk probabilities under various incident angles θ are as high as the calculated value for θ = 0°, and with a variation within 5.95%. The maximum variation of the longitudinal response and probability for track parts was within 10.59% under various incident angles, with a significant difference in the transverse response and probabilities in response to different incident angles. In addition, the responses of bridge structure components were more sensitive to the incident angles in comparison with the track parts. Finally, results indicate that the risk probabilities are at a maximum when the ground motions fall within horizontal orientations of 67.5°–90° at the bridge longitudinal axis.

3

Wykorzystanie analizy time-history podczas projektowania konstrukcji w rejonach aktywnych sejsmicznie

Bąk M.

Przegląd Budowlany

|

2017

|

R. 88, nr 5

37--46

PL

Obciążenia sejsmiczne ze względu na swój losowy charakter stanowią jedno z większych wyzwań stawianych współczesnej inżynierii. Na obszarze Polski problem naturalnej sejsmiczności jest niewielki i dotyczy głównie obszaru wzdłuż południowej granicy. Większe zainteresowanie trzęsieniami ziemi ma związek z coraz częstszym projektowaniem obiektów zlokalizowanych w rejonach o podwyższonej aktywności sejsmicznej, poza terenami Polski. Artykuł skupia się na odpowiednim wyborze danych, służących do przeprowadzania analiz w dziedzinie czasu (time-history), które ze względu na coraz większą uwagę zwracaną na przewidywanie zachowania konstrukcji (performance based design), są powszechniej stosowane.

EN

Due to their random nature, seismical loads pose one of greater challenges to modern engineering. Within the territory of Poland, the problem of natural seismicity is little and it concerns mainly the area along the southern border. Greater interest in earthquakes stems from more and more frequent cases of designing facilities located in regions with increased seismical activity outside Poland. The article focuses on adequate selection of data which serve to perform analyses in the time-history scope, which are more commonly used due to constantly growing attention devoted to predicting the construction behaviour (performance based design).

4

A GIS approach to seismic risk assessment with an application to mining-related seismicity in Johannesburg, South Africa

Liebenberg K., Smit A., Coetzee S., Kijko A.

Acta Geophysica

|

2017

|

Vol. 65, no. 4

645--657

EN

The majority of seismic activity in South Africa is related to extensive mining operations, usually in close proximity to densely populated areas where a relatively weak seismic event could cause damage. Despite a significant decrease in mining operations in the Witwatersrand area, the number of seismic events appears to be increasing and is attributed to the acid mine drainage problem. The increased seismicity is raising concern amongst disaster management centres and in the insurance industry. A better understanding is required of the vulnerability and the size of the potential loss of people and infrastructure in densely populated Johannesburg and its surrounding areas. Results of a deterministic seismic risk, vulnerability, and loss assessment are presented by making use of a geographic information system (GIS). The results illustrate the benefits of using GIS and contribute to a better understanding of the risk, which can assist in improving disaster preparedness.

5

Sposób zmniejszania ryzyka sejsmicznego w kopalniach KGHM Polska Miedź S.A. metodą monitorowania deformacji otworów wiertniczych

Orzepowski S., Butra J.

Rudy i Metale Nieżelazne

|

2011

|

R. 56, nr 2

59-63

PL

W celu monitorowania "bezpiecznej" transformacji skały w filarze górniczym ze stanu sprężystego do stanu pokrytycznego, powodowanej postępem frontu wydobywczego, opracowano czujnik deformacji otworu wiertniczego typu DL (Diameter- Length). Czujnik instalowany w centralnym obszarze filara mierzy wartość D - zmianę średnicy poziomego otworu w kierunku pionowym oraz L - deformację skały otaczającej otwór mierzoną w kierunku osi otworu (obie mierzone z rozdzielczością pomiarową nie gorszą od 2 mikrometrów). Specyficzna relacja pomiędzy mierzonymi wartościami D i L w czasie procesu eksploatacji złoża, potwierdza "bezpieczną" transformację skały jądra filaru do stanu pokrytycznego, albo wskazuje, że jądro filara znajduje się nadal w stanie sprężystym. W takich przypadkach konieczne są aktywne działania profilaktyczne, np. zastosowanie strzelania odprężającego dla uniknięcia tąpnięcia filara.

EN

In order to monitor a "safe" transformation of mine pillar core from elastic to the post-critical state caused by the advancing mining faces, sensor for borehole deformation measurement of DL (Diameter-Length) type was developed. The sensor, installed in the central area of the pillar, measures the D - vertical diameter deformation of the horizontal borehole and L - deformation of the rock-mass along the axis of borehole (both with definition better than 2 micrometers). Specific relationship between D and L values, measured during the mining face progress, confirms "safe" transformation of the pillar core into the post?critical state or indicates an "unsafe" one, which means that pillar remains in the dangerous elastic state. In this case, relaxing blasts are necessary to avoid the risk of pillar type bump.

6

Czy w Polsce potrzebna jest sejsmiczna norma budowlana?

Zembaty Z., Wiejacz P.

Czasopismo Techniczne. Budownictwo

|

2007

|

R. 104, z. 2-B

127-134

PL

Weryfikacja ryzyka sejsmicznego terenu Europy, podjęta m.in. w związku z wprowadzaniem od 2010 r. eurokodów w krajach UE, wskazała na istnienie zagrożenia sejsmicznego na terytorium Słowacji, Czech i Polski Południowej. W niniejszym artykule rozważa się, czy wzorem Słowacji lub Czech także na terenie naszego kraju nie należałoby wprowadzić odpowiedniej strefy sejsmicznej Eurokodu 8. Wstępna analiza ryzyka sejsmicznego terytorium Polski wskazuje, że choć powszechne wprowadzenie w Polsce normy sejsmicznej nie wydaje się uzasadnione, to jednak w procesie projektowania budowle specjalne i monumentalne (np. elektrownie atomowe i duże tamy) powinny być poddane sprawdzającym procedurom analiz sejsmicznych poprzedzonych szczegółowymi analizami ryzyka sejsmicznego.

EN

Year 2010 marks the beginning of the process of implementation of Eurocodes in the EU states. This includes also the Eurocode 8 dealing with seismic effects on structures. A wide scale verification of the European seismic risk revealed a minor and moderate seismic risk for Slovakia, Czech Republic and Southern Poland. The paper considers whether also Polish territory should be treated as potential Eurocode 8 seismic zone. An analysis of seismic risk suggests that although the data gathered so far do not suggest any necessity for conventional seismic building code to be applied on Polish territory, the special and monumental structures (e.g. nuclear power plants or big dams) may require more advanced analyses of their seismic risk and respective detailed seismic calculations.

7

Use of GIS for the preparation of an action plan for seismic risk management in the city of Thessaloniki

Axioti H., Doukas I., Savvaidis P.

Reports on Geodesy

|

2006

|

z. 5/80

363--372

8

On the seismic source regions in Macedonia-Bulgaria border area

Pekevski L., Glavcheva R., Hadzievski D., Botev E.

Reports on Geodesy

|

2006

|

z. 5/80

375--384

9

Earthquake ground motion scenarios in urban areas: the case of the city of Thessaloniki (Northern Greece)

Roumelioti Z., Kiratzi A., Theodulidis N., Panou A., Savvaidis A., Benetatos C.

Reports on Geodesy

|

2006

|

z. 5/80

303--317