scholarly journals Estimation of Peak Ground Acceleration from Horizontal Rigid Body Displacement: A Case Study in Port-au-Prince, Haiti

2012 ◽  
Vol 102 (6) ◽  
pp. 2704-2713 ◽  
Author(s):  
S. E. Hough ◽  
T. Taniguchi ◽  
J.-R. Altidor
Author(s):  
Jian S. Dai

Rigid body displacement can be presented with Chasles’ motion by rotating about an axis and translating along the axis. This motion can be implemented by a screw transformation matrix in the form of either 3×3 dual number matrix or 6×6 transformation matrix that is executed with rotation and translation. This paper investigates characteristics of the screw transformation matrix, and decomposes the dual part of the transformation matrix into the part with an equivalent translation due to the effect of moving rotation axis and the part resulting from a pure translation. New results are presented and new formulae are generated. The analysis further reveals two new traces of the transformation matrix and presents the relation between the screw transformation matrix and the instantaneous screw, leading to the understanding of Chasles’ motion embedded in a normal body transformation. An algebraic and geometric interpretation of the screw transformation matrix is thus given, presenting an intrinsic property of the screw transformation matrix in relation to the finite screw. The paper ends with a case study to verify the theory and illustrate the principle.


2020 ◽  
Vol 1 (3) ◽  
pp. 22-26
Author(s):  
Erdem Bayrak

Turkey is located on the Mediterranean-Himalayan seismic belt, which is the second largest earthquake zone in the world. Due to the fact that Erzurum basin is located in the Eastern Anatolia Region, it has a very complex structure in terms of its geological, tectonic and morphological features. Erzurum has been affected by destructive earthquakes throughout history. Some of these are Erzincan earthquake (26 December 1939), Horasan-Narman earthquake (30 October 1983), Spitak-Armenia earthquake (7 December 1988). In this study, the acceleration data of Erzurum-Aşkale (Mw=4.7) was used in order to estimate the peak ground acceleration using attenuation relationships. Attenuation relationships are important to determine how the peak ground acceleration decreases with distance. The data was recorded at twenty accelerometers in and around Erzurum. Peak ground accelerations were estimated according to Sadigh et al. (1997), Ambraseys et al. (1996), Kalkan and Gülkan (2004) attenuation relationships. As a result of calculations and comparisons, attenuation relationship of Sadigh et al. (1997) has found to be appropriate to the acceleration values recorded in the stations and has given the best results for the different soil types.


2015 ◽  
Vol 17 (1) ◽  
pp. 99
Author(s):  
Cloudya Gabriella Kapojos ◽  
Gerald Tamuntuan ◽  
Guntur Pasau

ANALISIS PERCEPATAN TANAH MAKSIMUM DENGAN MENGGUNAKAN RUMUSAN ESTEVA DAN DONOVAN (Studi Kasus Pada Semenanjung Utara Pulau Sulawesi) ABSTRAK Telah dilakukan analisis percepatan tanah maksimum di semenanjung utara Pulau Sulawesi dengan menggunakan rumusan Esteva dan rumusan Donovan. Data yang digunakan adalah data gempa bumi tektonik yang terjadi di sekitar semenanjung utara Pulau Sulawesi pada periode tahun 2008 – 2014. Hasil analisis menunjukkan bahwa perubahan nilai percepatan tanah dari rumusan Esteva dan rumusan Donovan memiliki pola perubahan yang sama terhadap jarak. Nilai percepatan tanah menurut rumusan Donovan lebih tinggi dibandingkan dari rumusan Esteva. Perbandingan dengan data akselerograf mengindikasikan bahwa rumusan Esteva lebih cocok digunakan dalam mengestimasi percepatan tanah maksimum di semenanjung utara Pulau Sulawesi. Hasil pemetaan sebaran percepatan tanah maksimum menunjukkan bahwa wilayah Kabupaten Minahasa Utara berada pada zona dengan resiko yang lebih tinggi dibandingkan wilayah lainnya di semenanjung utara Pulau Sulawesi. Kata Kunci :Percepatan tanah maksimum, gempa bumi, semenanjung utara Pulau Sulawesi ANALYSIS OF PEAK GROUND ACCELERATION USING ESTEVA AND DONOVAN FORMULATIONS (A Case Study On The Northern Part of Sulawesi) ABSTRACT Peak ground acceleration on the northern part of Sulawesi Island has been analysis by using Esteva and Donovan formulations. We use tectonic earthquake data that occurred around the northern part of Sulawesi Island during period of 2008 till 2014. The results showed that both Esteva and Donovan formulations have the similar pattern on changes of peak ground acceleration to the distance. Value of peak ground acceleration calculated with Donovan method higher than Esteva method. Comparison between empirical formula results and accelerograf data show that Esteva formulation more suitable for use in estimating the peak ground acceleration in the northern part of Sulawesi Island. Distribution of peak ground acceleration indicate that the earthquake impact on North Minahasa Regency is higher than other regions in northern part of Sulawesi island. Keynotes: Peak Ground Acceleration, Earthquake, Northern Part of Sulawesi Island


2018 ◽  
Vol 4 (2) ◽  
pp. 14
Author(s):  
Imam Trianggoro Saputro ◽  
Mohammad Aris

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.


Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 74
Author(s):  
Luis A. Pinzón ◽  
Luis G. Pujades ◽  
Irving Medranda ◽  
Rodrigo E. Alva

In this work, the directionality effects during the MW 7.8 earthquake, which occurred in Muisne (Ecuador) on 16 April 2016, were analyzed under two perspectives. The first one deals with the influence of these effects on seismic intensity measures (IMs), while the second refers to the assessment of the expected damage of a specific building located in Manta city, Ecuador, as a function of its azimuthal orientation. The records of strong motion in 21 accelerometric stations were used to analyze directionality in seismic actions. At the closest station to the epicenter (RRup = 20 km), the peak ground acceleration was 1380 cm/s2 (EW component of the APED station). A detailed study of the response spectra ratifies the importance of directionality and confirms the need to consider these effects in seismic hazard studies. Differences between IMs values that consider the directionality and those obtained from the as-recorded accelerograms are significant and they agree with studies carried out in other regions. Concerning the variation of the expected damage with respect to the building orientation, a reinforced concrete building, which was seriously affected by the earthquake, was taken as a case study. For this analysis, the accelerograms recorded at a nearby station and detailed structural documentation were used. The ETABS software was used for the structural analysis. Modal and pushover analyses were performed, obtaining capacity curves and capacity spectra in the two main axes of the building. Two advanced methods for damage assessment were used to obtain fragility and mean damage state curves. The performance points were obtained through the linear equivalent approximation. This allows estimation and analysis of the expected mean damage state and the probability of complete damage as functions of the building orientation. Results show that the actual probability of complete damage is close to 60%. This fact is mainly due to the greater severity of the seismic action in one of the two main axes of the building. The results are in accordance with the damage produced by the earthquake in the building and confirm the need to consider the directionality effects in damage and seismic risk assessments.


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