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Abstrak :

Kota Palu sebagai bagian Provinsi Sulawesi Tengah secara tektonik berada dekat dengan sumber gempa aktif crustal, yaitu sesar segmen Sulawesi Tengah. Sesar tersebut terdiri dari banyak segmen, diantaranya yang sudah dikenal adalah Sesar Besar Palu-Koro memanjang dari utara ke selatan. Di ujung selatan terhubung sesar Matano dan di utara terhubung dengan subduksi Utara Sulawesi (North Sulawesi Subduction) dan Selat Makasar bagian utara. Pembangunan infrastruktur berbasis mitigasi kegempaan di Indonesia merujuk Peraturan Bangunan Tahan Gempa berdasarkan Peta Bahaya Gempabumi SNI 1726 Tahun 2019. Kota Palu dan wilayah sekitar sesar segmen Sulawesi Tengah menjadi wilayah yang perlu dilakukan penelitian dengan mempertimbangkan efek kondisi site lokal. Parameter kondisi lokal meliputi jenis situs tanah, periode dominan tanah metode Horizontal to Vertical Spectral Ratio (HVSR) dan estimasi kedalaman bedrock menggunakan metoda Spatial Autocorrelation (SPAC) menjadi bagian parameter studi karakteristik ground motion di Kota Sulawesi Tengah. Penelitian ini menggunakan parameter gempa magnitudo gempa M_L 1,5-6,5. Pengolahan data ground motion menggunakan data hasil observasi sinyal 5 sensor Jaringan Strong motion Nasional BMKG sampling 100Hz, 5 sensor  jaringan strong motion terpasang sementara sampling 100Hz dan 25 sensor Jaringan Array Velocity Broadband dengan sampling 250 Hz. Jaringan khusus array ini hasil kerjasama BMKG dengan ANU (Australian National University) yang dipasang di sekitar Kota Palu dan dekat sesar segmen Sulawesi Tengah dalam durasi 3 bulan. Tujuan dalam studi ini adalah untuk mengkaji karakteristik dan pembangunan model ground motion segmen fault Sulawesi Tengah. Karakteristik ground motion model yang dibangun dikaji dari uji model regional dan lokal dengan katalog gempa utama (independent) dan gempa gabungan foreshock,mainshock dan aftershock (dependent). Hasilnya menunjukkan karakteristik ground motion hasil dependent mempunyai nilai hasil model yang lebih rendah dibandingan independent, fitting model regional menunjukkan hasil bervariasi tingkat kecocokannya terhadap data observasi masing-masing fault yaitu dengan melihat hasil garis korelasi terhadap data observasi dan hasil residualnya. Model tersebut diuji menggunakan data observasi gempa merusak 29 Mei 2017 Mw 6,6 dan gempa merusak 2018 magnitudo 7,4. Hasilnya menunjukkan model GMPE dependent mempunyai nilai estimasi GM-PGA model yang berada pada distribusi data observasi, sedangkan hasil model independent mempunyai tingkat kecocokan berada di atas sebaran data observasi. Sedangkan pengujian GMSA median M=3-4 dan M=4-5 model dependent dan independent terhadap dari data observasi M=3-4 dan M=4-5 di luar data pembangun model, menunjukkan hasil korelasi yang cukup baik terhadap dua model tersebut. Pemahaman kondisi site lokal menjadi sangat penting dan menjadi bagian dalam perhitungan GM-PGA dan dipertimbangkan dalam penentuan nilai estimasi tingkat goncangan dalam bagian desain infrastruktur mitigasi bencana gempa bumi.     

 

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Palu City in one major city in Indonesia which has administratively is the part of Central Sulawesi Province. It has the potential to develop the big infrastructure which has to consider mitigation aspect, due to tectonically it has located close to earthquake active source, particularly segments crustal zone of Central Sulawesi. Central Sulawesi fault has the many faults segmentation, it is called The Active Major Fault System of Central Sulawesi, as well known Palu Koro Fault System zone. It was along the north to southward close to Palu Valley. Development of infrastructure with earthquake hazard mitigation accordance to SNI 1726:2019. Local site classification parameters using the dominant period HVSR (Horizontal Vertical Spectral Ratio), estimation deep of engineering bedrock using SPAC method (Spatial Auto Correlation) as well done. The understanding of the local seismic condition and seismotectonic mechanism based on seismicity data are significantly contributing to know earlier the possibility of the amplification, which have related PGA value with the distance. In this study used 5 National Strong motion Network Station of  BMKG in Palu, 25 Array Network Broadband Velocity Temporarily Station of BMKG-ANU and 5 Regional Strong motion Network Temporarily Station along the Palu-Koro fault and short period for the mini regional network. The purpose of this research to study the characteristics of the local ground motion GM-PGA model from multi fault in Central of Sulawesi, with considered the local site effect.  All these parameters contribute to play roles within the form of the GMPE model.The characteristics of ground motion in this research using independent (mainshock)-independent (foreshock, mainshock, aftershock) regional and local earthquake catalog. The result showed characteristics of ground motion dependent has the calculated value is lower than independent, and the regional model showed the fitting variated to micro fault observed data. It can be seen using correlated regression and residuals. Moreover, when compared with two devastating earthquakes, 29th May 2017 Mw 6.6 and Palu earthquake Mw 7.4 showed that the dependent model is fitted well with distribution of observed data, while for the independent model is overestimated. Meanwhile to calibrate GMSA has used Median GMSA for M=3-4 and M=4-5 to GMSA data observed of M=3-4 and M=4-5. The results showed that the well correlated between of Median GMSA to data observed distribution. The Understanding of local seismic is very important to asses the related PGA value with the distance in GM-PGA and GMSA in GMPE. The GMPE model could be used to be considered in detail engineering design process to determine the level of potential shaking when implement development mitigation based.    

Abstrak :
Pergerakan massa tanah jenis rayapan umumnya berlangsung lambat dan dapat merusak infrastruktur yang ada. Litologi batuan penyusunnya dapat mengendalikan jenis longsoran ini; misalnya, batulempung, yang sebagian besar membentuk daerah penelitian, memiliki daya tahan rendah ketika mengalami pembasahan dan pengeringan berulang kali. Hal ini mengakibatkan penurunan sifat mekanik dan dinamis secara dominan. Adanya rekatan pada daerah penelitian juga menjadi faktor pengendali gerakan tanah. Retakan ini terjadi akibat pengembangan dan penyusutan serta peralihan parameter dari kategori batuan ke tanah akibat proses pelapukan sehingga menyebabkan penurunan kekuatan lempung. Secara morfologi daerah penelitian memiliki kemiringan lereng agak curam hingga curam, dan terdapat perbukitan intrusive di sekelilingnya serta area gerakan massa yang teraktivasi kembali. Penelitian ini bertujuan untuk mengidentifikasi karakteristik litologi daerah penelitian yang mengendalikan pergerakan massa dan kestabilan lereng. Metode yang digunakan adalah analisis XRD dan SEM, uji sifat fisik dan mekanik tanah, kemudian dikorelasikan dengan metode geolistrik dalam menganalisis karakteristik batulempung, metode kesetimbangan batas dengan prinsip Janbu. Hasil pemetaan geologi teknik membagi dua satuan yang terdiri dari pasir, lempung atau lanau dan andesit. Kontak antara kedua satuan tersebut menjadi bidang lemah atau bidang gelincir yang diperoleh dari pengolahan data geolistrik pada kedalaman 18 – 22meter dengan litologi napal. Kelompok mineral lempung ditemukan pada hasil uji SEM, dan terdapat indikasi mineral swelling yang diuji menggunakan glikol pada uji XRD. Analisis kestabilan lereng menghasilkan nilai faktor keamanan dari tiga bidang gelincir yang berbeda yaitu 0.849, 0.825, dan 0.818 sehingga mengklasifikasikan lereng dalam kondisi labil dengan tipe longsoran progresif. Intensitas hujan yang tinggi serta aliran sungai yang tertutup membuat tanah menjadi tidak stabil, sehingga longsoran mengalami perluasan. Oleh karena itu, diperlukan analisis lebih lanjut mengenai stabilisasi tanah lempung dan perencanaan penggunaan lahan di wilayah studi. ......Mass movement with creep generally takes place slowly and can damage existing infrastructure. The lithology of the constituent rocks can control this type of landslide; for example, claystone, which mainly forms the study area, has meagre resistance when subjected to repeated wetting and drying. This results in decreasing mechanical and dynamic properties dominantly. The existence of fractures in the study area also becomes a controlling factor for creeping landslides. These fractures occur as a result of swelling and shrinkage as well as the transition of parameters from rock to soil categories due to weathering processes, causing a decrease in shale clay strength. Morphologically the study area slopes to a slightly steep to steep, and intrusive hills surround it, and reactivated mass movement areas. This study aims to identify the lithological characteristics of the study area that control mass movement and slope stability. The methods used are XRD and SEM analysis, physical and mechanical properties of the soil, then correlated with the geoelectric method in analysing the characteristics of claystone, and the limit equilibrium method with the Janbu principle is used. The study results are a technical geological mapping divide rock and soil units based on physical properties and geomorphological condition into two units. The contact between these two units becomes a weak field or slip plane obtained from geoelectric data processing at a depth 18 - 22 meters with marl lithology. Clay mineral groups was found in the SEM test results, and there were indications of swelling minerals tested using glycol in the XRD test. Slope stability analysis produces a safety factor value with a three different slip planes, 0.849, 0.825, dan 0.818, thus classifying the slope unstable condition and with a progressive landslide. High-intensity and continuous rainfall and flooded river flows cause stagnant water, making the soil unstable, so the creeping landslide will be estimated to expand. Therefore, further analysis is needed regarding the stabilization of clay soil and land use planning in the study area.

Abstrak :
This book presents a simple analytical method based on the extended rod theory that allows the earthquake resistance of high-rise buildings to be easily and accurately evaluated at the preliminary design stage. It also includes practical software for applying the extended rod theory to the dynamic analysis of actual buildings and structures. High-rise buildings in large cities, built on soft ground consisting of sedimentary rock, tend to have low natural frequency. If ground motion due to an earthquake occurs at distant hypocenters, the vibration wave can be propagated through several sedimentary layers and act on skyscrapers as a long-period ground motion, potentially producing a resonance phenomenon that can cause severe damage. Accordingly, there is a pressing need to gauge the earthquake resistance of existing skyscrapers and to improve their seismic performance. This book was written by authors who have extensive experience in tall-building seismic design in Japan. The software included enables readers to perform dynamic calculations of skyscrapers resistance to vibrations. As such, it offers a valuable resource for practitioners and engineers, as well as students of civil engineering.

Abstrak :
This book focuses on the seismic design of Structures, Piping Systems and Components (SSC). It explains the basic mechanisms of earthquakes, generation of design basis ground motion, and fundamentals of structural dynamics; further, it delves into geotechnical aspects related to the earthquake design, analysis of multi degree-of-freedom systems, and seismic design of RC structures and steel structures. The book discusses the design of components and piping systems located at the ground level as well as at different floor levels of the structure. It also covers anchorage design of component and piping system, and provides an introduction to retrofitting, seismic response control including seismic base isolation, and testing of SSCs. The book is written in an easy-to-understand way, with review questions, case studies and detailed examples on each topic. This educational approach makes the book useful in both classrooms and professional training courses for students, researchers, and professionals alike.