scholarly journals Analysis of landslide in Bungkah, Sepakung, Banyubiru using ground shear strain method and shear wave profile from HVSR method

2021 ◽  
Vol 1943 (1) ◽  
pp. 012027
Author(s):  
G Yuliyanto ◽  
M I Nurwidyanto
2018 ◽  
Vol 2 (2) ◽  
pp. 222-226
Author(s):  
Kurnia Lestari ◽  
Muchammad Farid ◽  
Afrizal Mayub

ABSTRACT  [The Analysis of Shear Strain and Building Damage due to Earthquake at Gading Cempaka and Ratu Agung District in Bengkulu City]. The aims of this research are to: (1) determine and mapping the distribution of shear strain values, (2) correlate between shear strains with building damage Gading Cempaka and Ratu Agung caused by earthwuake at sub district in Bengkulu city. Microtremor data were taken at 108 observation points then analyzed using HVSR method to obtain amplification factor and dominant frequency values..The result showed that shear strain value of Gading Cempaka and Ratu Agung sub district in Bengkulu city are relatively heterogeneous although in the same geological formation type. The earthquake in 2007 is estimated to be 3.38% potential to deform the land surface in the form of fractures and settlements and 96, 62% potentially experience shocks due to waves and vibrations due to earthquake. The earthquake of 2000 estimated that almost the entire area of Gading Cempaka and Ratu Agung has the potential to experience shocks due to waves and vibrations due to earthquake that is equal to 97% while potentially liquefaction (ambles) occurs by 3%. The correlation between shear strain with the damage of buildings due to earthquake shows the relationship is directly proportional to the function y = 15267x + 26.219 with the coefficient of resgression of    = 0.671. Keywords:  Earthquake;  HVSR method;  microtremor;  shear strain.


2012 ◽  
Vol 39 (4) ◽  
pp. 43-46
Author(s):  
O.P. Kuznetsova ◽  
Yu.V. Bulygina ◽  
A.P. Tikhonov ◽  
E.V. Prut

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Kurnia Lestari ◽  
Muchammad Farid ◽  
Afrizal Mayub

ABSTRACT  [The Analysis of Shear Strain and Building Damage due to Earthquake at Gading Cempaka and Ratu Agung District in Bengkulu City]. The aims of this research are to: (1) determine and mapping the distribution of shear strain values, (2) correlate between shear strains with building damage Gading Cempaka and Ratu Agung caused by earthwuake at sub district in Bengkulu city. Microtremor data were taken at 108 observation points then analyzed using HVSR method to obtain amplification factor and dominant frequency values..The result showed that shear strain value of Gading Cempaka and Ratu Agung sub district in Bengkulu city are relatively heterogeneous although in the same geological formation type. The earthquake in 2007 is estimated to be 3.38% potential to deform the land surface in the form of fractures and settlements and 96, 62% potentially experience shocks due to waves and vibrations due to earthquake. The earthquake of 2000 estimated that almost the entire area of Gading Cempaka and Ratu Agung has the potential to experience shocks due to waves and vibrations due to earthquake that is equal to 97% while potentially liquefaction (ambles) occurs by 3%. The correlation between shear strain with the damage of buildings due to earthquake shows the relationship is directly proportional to the function y = 15267x + 26.219 with the coefficient of resgression of    = 0.671. Keywords:  Earthquake;  HVSR method;  microtremor;  shear strain.


2021 ◽  
Vol 873 (1) ◽  
pp. 012085
Author(s):  
Najla Insyirah Lianza Bakri ◽  
Tedi Yudistira ◽  
Yayan Sopyan

Abstract Tasikmalaya City is one of the regions in West Java Province that is often hit by earthquakes due to its location near the Indo-Australian Plate subduction zone towards the Eurasian Plate. The surface deposits in this city are alluvium and weakly consolidated step deposits which can cause wave amplification during an earthquake. As a mitigation effort, seismic zoning needs to be carried out to map the areas that will experience heavy damage when an earthquake occurs. This study uses the Horizontal to Vertical Spectral Ratio (HVSR) method which is applied to the microtremor recording data to obtain spatial variations in the predominant frequency and amplification values that can explain the characteristics of the geological layer beneath the surface. Based on the obtained results, the predominant frequency ranging from 0.7 to 9.5 Hz with the lowest frequency distribution in the eastern and northwestern parts, which indicates a thicker sediment layer. Amplification ranging from 1.2 to 12.6 with the distribution of higher values in the eastern, southeastern, and northwestern parts. The inversion of the HVSR curves was carried out to determine the value of shear wave velocity (V s ) in order to obtain a more detailed subsurface geological structure that can be used to determine the level of vulnerability of earthquake hazards. The Neighborhood Algorithm is used to find an optimum model. Based on the results of the inversion process, the V s ranging from 150 - 3054 m/s with lower V s values in the eastern, southeastern, and northwestern parts at depth of about 25 meters. The average value of shear wave velocity at a depth of 30 meters (V s 30) can also be used to determine the type of soil for geotechnical study. From the obtained V s 30data, the types of soil in the research area are classified into moderate soil, hard soil, and rocks.


Author(s):  
Anders Batman Mjelle ◽  
Anesa Mulabecirovic ◽  
Roald Flesland Havre ◽  
Edda Jonina Olafsdottir ◽  
Odd Helge Gilja ◽  
...  

Abstract Purpose Liver elastography is increasingly being applied in screening for and follow-up of pediatric liver disease, and has been shown to correlate well with fibrosis staging through liver biopsy. Because time is of the essence when examining children, we wanted to evaluate if a reliable result can be achieved with fewer acquisitions. Materials and Methods 243 healthy children aged 4–17 years were examined after three hours of fasting. Participants were divided into four age groups: 4–7 years; 8–11 years; 12–14 years and 15–17 years. Both two-dimensional shear wave elastography (2D-SWE; GE Logiq E9) and point shear wave elastography (pSWE; Samsung RS80A with Prestige) were performed in all participants, while transient elastography (TE, Fibroscan) was performed in a subset of 87 children aged 8–17 years. Median liver stiffness measurement (LSM) values of 3, 4, 5, 6, 7, and 8 acquisitions were compared with the median value of 10 acquisitions (reference standard). Comparison was performed for all participants together as well as within every specific age group. We investigated both the intraclass correlation coefficient (ICC) with absolute agreement and all outliers more than 10 %, 20 % or ≥ 0.5 or 1.0 kPa from the median of 10 acquisitions. Results For all three systems there was no significant difference between three and ten acquisitions, with ICCs ≥ 0.97. All systems needed 4 acquisitions to achieve no LSM deviating ≥ 1.0 kPa of a median of ten. To achieve no LSM deviating ≥ 20 % of a median of ten acquisitions, pSWE and TE needed 4 acquisitions, while 2D-SWE required 6 acquisitions. Conclusion Our results contradict recommendations of 10 acquisitions for pSWE and TE and only 3 for 2D-SWE.


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