Hasil Pencarian  ::  Simpan CSV :: Kembali

"Telah dilakukan proses tomografi struktur kecepatan gelombang seismik Gelombang P menggunakan data gempabumi swarm di daerah Jailolo, Halmahera Barat, Maluku Utara. Penelitian ini bertujuan menentukan parameter gempabumi dan sebarannya yang ada diwilayah ini, menganalisis perbedaan antara rangkaian gempabumi swarm dengan gempabumi tektonik non swarm, dan menganalisis struktur kecepatan gelombang P Vp pada wilayah ini dan implikasinya terhadap keadaan tektonik lokal diwilayah ini yang menjadi penyebab gempabumi swarm Jailolo 2015. Digunakan rekaman data seismik 12 Agustus-12 September 2016 dari 33 stasiun yang ada pada jaringan 7G Seismic Temporary Network GFZ GeoForschungsZentrum ndash; German Reserarch Centre for Geosciences Helmholtz Centre Postdam dan BMKG Badan Meteorologi Klimatologi dan Geofisika , yang dianalisis menggunakan JISVIEW, sebuah program analisis gempabumi. Program simulps12 digunakan untuk melakukan proses inversi tomografi simultan. Dari rekaman seismik yang ada teranalisis 264 kejadian gempabumi sebelum relokasi yang kemudian menjadi 219 kejadian gempabumi setelah relokasi , yang digunakan dalam tahapan proses tomografi. Kejadian gempabumi yang ada diidentifikasi sebagai rangkaian kejadian gempabumi swarm, bukan kejadian gempabumi tektonik biasa non swarm yang memiliki pola foreshock-mainshock-aftershock. Dari gambar hasil tomografi diketahui adanya daerah dengan perturbasi nilai Vp tinggi diasumsikan sebagai magma yang mengalami intrusi magmatik dimasa lalu dan telah mendingin menjadi bagian batuan beku. Vp rendah dikedalaman diasumsikan sebagai intrusi magma yang sedang terjadi dari mantel bagian atas yang mendorong bagian lemah pada batuan beku dibagian kerak bumi bagian bawah diwilayah, sehingga mengakibatkan rangkaian gempabumi swarm pada akhir tahun 2015.

---

The process of tomography for seismic velocity structure P wave has been done using swarm earthquake data in Jailolo, Halmahera Barat, and North Molucca. The objectives of this research are determining the earthquake parameters and its hypocentre and epicentre around research areas, analysing the difference between swarm and non swarm earthquake tectonic earthquake, and analysing the structure of P wave velocity Vp structures and correlating the results with the local and regional geological structure that became the source of swarm earthquake phenomenon in 2015.

A 32 days August 12 September 12 2016 seismic data recording, from 33 seismic station in 7G Seismic Temporary Network of GFZ GeoForschungsZentrum ndash German Research Centre for Geosciences Helmholtz Centre Postdam and BMKG Agency of Meteorology, Climatology and Geophysics , is analysed using JISVIEW, an earthquake analysis program.

Simulps12 program is used to do the simultaneous tomography inversion. From the seismic recording, we analysed 264 earthquake events before relocation, and after relocation process we used 219 earthquake events to do the inversion process. The earthquake event that analysed in research areas is identified as a swarm earthquake sequence, not am ordinary tectonic earthquake.

From tomography imaging result we found a region high Vp perturbance values that interpreted as a igneous rock of magma bodies from previous magmatic intrusion in the past. A low Vp perturbance values in the depth is interpreted as on going magmatic intrusion from upper earth mantle layer that pushing the weak zones at lower earth crust layer that caused the sequence of swarm earthquake in 2015."

"Multiple lapisan bawah air merusak refleksi primer dan membuangnya dari data seismik seismogram telah menjadi permasalahan sejak dulu bagi ahli geofisika, pengolahan data seismik. Jika multiple ini tidak dibuang, kehadirannya dapat membuat interpretasi data seismik menjadi sulit dan menghasilkan analisa yang salah. Tesis ini bertujuan untuk mempelajari konsep dan teori dibalik metode Surface Relative Multiple Elimination (SRME), serta kekuatan dan kelemahan dalam aplikasinya dengan menggunakan data sintetis dan rill. Data sintetik dibangun menggunakan software TESSERAL 2D dan data riil yang dipilih adalah survei North West Shelf Regional (NWSR). Hasil dari skema aliran kerja dan parameter test yang terbaik untuk data sintetik dapat digunakan sebagai acuan pada proses data lapangan survei NWSR. Analisa menunjukkan bahwa ada hubungan yang konsisten antara keberhasilan hasil data sintetik dengan data lapangan. Hasil dari seluruh penelitian tesis ini menyimpulkan bahwa metode SRME sangat efektif membuang multiple lapisan bawah air pada near offset tetapi masih menyisakan mutiple pada far offset.

---

Water bottom multiples destructively interfere with primary reflections and their removal from reflection seismograms has been a longstanding problem to seismic processing geophysicists. If not eliminated, their presence could make seismic data interpretation difficult and lead to erroneous results. This thesis is aimed to study concept and theory behind the Surface Relative Multiple Elimination (SRME), as well as the strengths and weaknesses in application by using synthetic and field data. Synthetic data was created by using TESSERAL 2D software and field data that was chosen in this research was seismic data from North West Shelf Regional (NWSR) survey. The work flows scheme and the best parameter of the tests for the synthetic data were used as a guide in processing of NWSR. It showed that there was a consistent result between the synthetic and field data. The results of this study had conclusion that SRME method was effective in near offset but there was still remaining multiple at far offset."

"Migrasi seismik merupakan salah satu proses akhir dalam processing seismik. Proses migrasi bertujuan untuk meningkatkan resolusi lateral data seismik dengan cara memindahkan kedudukan reflektor pada posisi dan waktu pantul yang sebenarnya berdasarkan lintasan gelombang. Hal ini disebabkan karena penampang seismik hasil stack belumlah mencerminkan kedudukan yang sebenarnya, karena rekaman normal incident belum tentu tegak lurus terhadap bidang permukaan, terutama untuk bidang reflektor yang miring. Selain itu, migrasi juga dapat menghilangkan pengaruh difraksi gelombang yang muncul akibat pengaruh struktur geologi seperti patahan, sinklin, dan antiklin. Migrasi yang digunakan dalam penelitian ini, yaitu migrasi dengan menggunakan metode fourier split step dan finite-difference. Kedua metode migrasi yang digunakan tersebut diaplikasikan pada empat macam data seismik sintetik yang telah dibuat melalui pemodelan seismik Data seismik sintetik yang dibuat terdiri dari empat macam model geologi, yaitu model geologi dua perlapisan (sinklin-antiklin), model geologi tiga perlapisan (patahan), dan model geologi empat perlapisan dan satu channel, pada model geologi yang ketiga ini terdapat dua macam model kecepatan, yaitu model yang memiliki kecepatan kontinu dan model yang memiliki kecepatan tidak kontinu. Dilakukan perbandingan antara kedua metode migrasi yang digunakan terhadap data seismik sintetik yang ada. Hasil migrasi dengan menggunakan metode finite-difference terlihat lebih baik dalam mengatasi variasi kecepatan lateral yang sederhana maupun kompleks dibandingkan dengan metode fourier split step. Tapi, migrasi dengan menggunakan metode fourier split step lebih membutuhkan waktu yang singkat dalam hal proses komputasi dibandingkan metode finite-difference.

---

Seismic migration is a part of final process in seismic processing. The purpose of migration is to enhance spatial resolution of seismic data. This migration is performed by moving the position of reflector with regards to the real position and reflecting time based on the wave path. The different image between the stacked section and true subsurface position of the event due to the record of normal incidence is not always perpendicular to its reflector, especially a reflector with a certain dip. In addition, migration collapse diffraction effect is shown from the result of geological structure such as fault, sincline and anticline.

The migration algorithm that was used is split step fourier and finite-difference migration. Both migration methods were applied to four types of synthetic seismic data that were produced by seismic modeling. The produced synthetic seismic data consisted of four types of geological modeling which are: double layered geological model (syncline - anticline), triple layered geological model (fault), four layered geology model, and one channel. For the third geological models it was found that there were two types of velocity model, a continual velocity and the other was not. Comparison was then done for the two migration methods used with the existing synthetic seismic data.

The results show that finite-difference migration is better than split step fourier migration in solving and handling variation of a simple and complex lateral velocity. In contrast, split step fourier migration is faster than finite-difference migration in the computation process."

"[Penelitian ini membahas mengenai analisis perilaku dinamik struktur bangunan tahan gempa dengan perletakan terisolasi dengan cara membandingkannya dengan bangunan dengan perletakan tetap. Bangunan dengan perletakan terisolasidimodelkan dengan menggunakan base isolation yang sesuai dengan yang digunakan oleh rumah sakit UI, sementara bangunan dengan perletakan tetap dimodelkan dengan menggunakan perletakan jepit. Beban gempa yang digunakanadalah beban gempa riwayat waktu northridge, kobe, dan el-centro yang telah diskalakan dengan respon spektrum Depok sesuai dengan SNI 1726:2012 Tata cara perencanaan ketahanan gempa untuk struktur gedung dan non gedung.Analisa yang digunakan yaitu nonlinear time history direct integration. Nonlinearitas dari bangunan didapatkan dari material dan geometri yang diwakilkan oleh sendi plastis pada bangunan dengan perletakan tetap dan base isolator yang telah berdeformasi melebihi batas lelehnya pada bangunan dengan perletakan terisolasi. Dari hasil penelitian menunjukkan penggunaan base isolator pada struktur bangunan tahan gempa meningkatkan peforma bangunan akibat beban gempa, serta memperkecil gaya dalam element-element struktur bangunan.

---

This study discusses the comparison of the dynamic behaviour analysis of the isolated base seismic structure and fixed base structure. The isolator used in the mathematical model of the isolated base structure in this study is the same with the isolator that will be used in the real UI Hospital Building, while the fixed base structure modeled by rigid base. The seismic load used in this study are time history seismic load of Northridge, Kobe, and El Centro. The time history is scaled by the factor appropriate with SNI 1726:2012. Nonlinear time history direct analysis method will be performed in this study. The nonlinearity of the structure consists of geometrical nonlinearity and material nonlinearity gained

from the plastic hinge and the deformation of the isolator that exceed its yield deformation point. Result shows that isolated base structure has better performances than fixed base structure. It showed by the decreasing amount of the

internal forces of each elements of the structure.;This study discusses the comparison of the dynamic behaviour analysis of the isolated base seismic structure and fixed base structure. The isolator used in the mathematical model of the isolated base structure in this study is the same with the isolator that will be used in the real UI Hospital Building, while the fixed base structure modeled by rigid base. The seismic load used in this study are time history seismic load of Northridge, Kobe, and El Centro. The time history is scaled by the factor appropriate with SNI 1726:2012. Nonlinear time history

direct analysis method will be performed in this study. The nonlinearity of the structure consists of geometrical nonlinearity and material nonlinearity gained from the plastic hinge and the deformation of the isolator that exceed its yield deformation point. Result shows that isolated base structure has better performances than fixed base structure. It showed by the decreasing amount of the

internal forces of each elements of the structure.;This study discusses the comparison of the dynamic behaviour analysis of the

isolated base seismic structure and fixed base structure. The isolator used in the

mathematical model of the isolated base structure in this study is the same with

the isolator that will be used in the real UI Hospital Building, while the fixed base

structure modeled by rigid base. The seismic load used in this study are time

history seismic load of Northridge, Kobe, and El Centro. The time history is

scaled by the factor appropriate with SNI 1726:2012. Nonlinear time history

direct analysis method will be performed in this study. The nonlinearity of the

structure consists of geometrical nonlinearity and material nonlinearity gained

from the plastic hinge and the deformation of the isolator that exceed its yield

deformation point. Result shows that isolated base structure has better

performances than fixed base structure. It showed by the decreasing amount of the

internal forces of each elements of the structure., This study discusses the comparison of the dynamic behaviour analysis of the

isolated base seismic structure and fixed base structure. The isolator used in the

mathematical model of the isolated base structure in this study is the same with

the isolator that will be used in the real UI Hospital Building, while the fixed base

structure modeled by rigid base. The seismic load used in this study are time

history seismic load of Northridge, Kobe, and El Centro. The time history is

scaled by the factor appropriate with SNI 1726:2012. Nonlinear time history

direct analysis method will be performed in this study. The nonlinearity of the

structure consists of geometrical nonlinearity and material nonlinearity gained

from the plastic hinge and the deformation of the isolator that exceed its yield

deformation point. Result shows that isolated base structure has better

performances than fixed base structure. It showed by the decreasing amount of the

internal forces of each elements of the structure.]"

"Bunyi dapat menjadi polusi suara terutama di kota besar seperti Jakarta dengan semakin banyaknya kendaraan dijalan, bunyi yang dihasilkan oleh mesin kendaraan bisa sangat mengganggu. Namun bunyi yang datang bisa kita redam dengan memilih material yang tepat di dalam rumah kita. Pada penelitian kali ini kami membuat rancang bangun yang dapat mengetahui nilai koefisiens transmisi dari suatu material. Komponen yang kami pakai dalam penelitian ini adalah XR 2206 sebagai pembangkit sinyal, power amplifier, Speaker, Arduino KY-038 sebagai sensor microphone, peak to peak detector, dan mikrokontroler. Kami menggunakan pipa paralon sepanjang 1 meter sebagai media perambatan gelombang. Pada bagian dalam pipa kami melapisinya dengan rockwool agar sistem kedap suara. Rentang frekuensi yang dipakai dalam penelitian ini adalah 100-9.000 Hz. Material uji yang digunakan adalah rockwool, gypsum, dan triplek. Dengan membandingkan amplitudo yang diterima sensor setelah dipasang material uji dan sebelum dipasang material uji kita dapat mengetahui koefisiens transmisi material tersebut. Setelah kita menguji ke-tiga material tersebut kami mendapatkan bahwa pada rentang frekuensi 600-2000 Hz nilai koefisiens transmisi selalu lebih besar dibandingkan titik frekuensi lainnya.

---

The sound can be noise pollution especially in big cities such as Jakarta with the increasing number of vehicles in the streets the sound produced by the engine vehicles can be very disturbing. But the sound that comes can we asunder by selecting the right material in our houses. Research on this time we make the building blocks that can know the value of transmission koefisiens from a material. The components that we use in this research is the XR 1059 as power signal, Power Amplifier, Speaker, Arduino Judicial Commission-038 as a microphone sensor, peak to peak detector, and mikrokontroler. We use the tube paralon over 1 meter as media propagation waves. On the inside of the tube we overlaid them with rockwool so that the system is insulated from sound. The frequency range used in this research is 100-9,000 Hz. The test material used is rockwool, gypsum, and plywood. By comparing the received amplitudo after it is installed sensor test material and before the attached test material we can know the material transmission koefisiens. After we test to three of the material we get that at the frequency range from 600-2000 Hz the amplitude is always rise."

"ABSTRAKEvaluating the effectiveness of dynamic vibration absorber (TMDs) in order to reduce vibration of equivalent SDOF system subjected to white noise random excitation is considered. This evaluation is limited to the displament response only and performed using RMS.Response Ratio, Performance and Effective Damping concepts. The Optimum Tuning and Damping of this system especially the damped one is determined using Iterative Process and formulas for these two optimum parameters also derived by using Regression Analysis. The behavior and effectiveness of this system under Simulated Earthquake also evaluated using SIMULINK Programs and in addition to this equivalent SDOF model (1st mode modelization) ,we try to see complete structural modeling for comparison. It is the MDOF model with State-Space Formulation."

"Telah dilakukan penelitian pada reservoar karbonat di Lapangan "D" yang terletak pada cekungan Jawa Timur. Inversi seismik extended elastic impedance (EEI) digunakan untuk mengidentifikasi distribusi reservoar hidrokarbon pada reef karbonat. Pada sudut tertentu (χ) diperoleh nilai korelasi yang tinggi antara log target dengan log EEI yang merupakan best chi angle yang digunakan dalam membuat volum seismik scaled reflectivity. Korelasi log EEI dengan log LMR cukup besar dengan nilai sudut χ sebesar 12º (r=0.987287478) untuk parameter Lamda Rho, sedangkan parameter Mu Rho diperoleh nilai sudut χ sebesar -13º (r=0.995584548). Post stack inversi seismik sparse spike digunakan terhadap volum scaled reflectivity untuk mendapatkan seismik cube LMR. Sebagai hasilnya, sensitivitas parameter LMR terhadap keberadaan hidrokarbon digunakan untuk mengetahui kandungan fluida reservoar. Sumur D-02 memiliki potensi kandungan hidrokarbon yang cukup banyak dibandingkan dengan sumur D-01. Kemudian hasil inversi EEI digunakan untuk mengetahui penyebaran reservoar karbonat yang berarah Utara semakin dalam menyebar kearah Selatan dan membelok kearah Barat Daya.

---

A study of characterization of carbonate reservoir has been done in Field "D" located at East Java basin. Extended elastic impedance (EEI) seismic inversion was applied to identify the distribution of hydrocarbon reservoir in a reef carbonate. At a certain angle (  ) obtained high correlation between target log and EEI log that best chi angle which is used to make scaled reflectivity seismic cube. Correlation EEI log with target log is good enough at a value of  angle 12º (r = 0.987287478) for Lambda Rho parameters, while the Mu Rho parameter obtained the value of  angle -13º (r = 0.995584548). Post Stack Sparse Spike Seismic Inversion is applied to scaled reflectivity seismic cube to get LMR seismic cubes. As Results, sensitivity of LMR parameter with the presence of hydrocarbons is used the fluid content of reservoir. D-02 well has potential hydrocarbon content than D-01 well. Then, EEI inversion results are used to determinate carbonate reservoir distribution that its direction at North so deeply the distribution spread to South and divert to Southwest."