Seismic Response Validation of Simulated Soil Models to Vertical Array Record During A Strong Earthquake

Several soil models, such as linear elastic, equivalent linear, and non-linear models, are employed in seismic ground response analysis. The aim of this study was to validate the seismic responses at ground surface of several soil models with the vertical array record of the Kobe earthquake. One-dimensional seismic response analyses were performed at Port Island using several soil models. The responses at ground surface from the simulated soil models were validated with the vertical array record of the Kobe earthquake. The results showed that the extended hyperbolic model yielded the most appropriate response according to the Kobe earthquake's recorded motion. This means that this model can be considered a suitable soil model to predict the response of strong earthquakes. In general, the results support the recommendation to select the most appropriate soil model for seismic ground response analysis

Analisis Perancangan Dinding Penahan Tanah Untuk Seawater Intake Pembangkit Listrik Tenaga Uap

Abstract The handling of retaining walls in the PLTU seawater intake project is a crucial part in maintaining the stability of buildings below ground level. The retaining wall construction is selected based on the depth of excavation, soil type, the height of the Groundwater Table (GWT), and the load being retained. The lateral force calculation method uses Rankine and Coulomb theories with specified soil parameters. The case study was conducted at the seawater intake area of Java 9 & 10 Suralaya PLTU in Suralaya, Cilegon, Banten. The design process involved soil data interpretation, site class determination, and stability analysis using MIDAS GTS NX software. The retaining wall design is divided into two parts, using diaphragm walls and secant piles. The use of lateral reinforcement in the form of soil anchors is adjusted to the provisions of SNI 8460-2017. The design results show that the wall and anchor configurations meet the design criteria, with appropriate values of safety numbers and lateral deflections. However, the selection of Mohr-Coulomb soil model and pseudostatic earthquake analysis produced more conservative results. In conclusion, the retaining wall design proved to be effective in handling the lateral soil loads and pressures in the seawater intake PLTU project.Abstrak Penanganan dinding penahan tanah pada proyek seawater intake PLTU merupakan bagian krusial dalam menjaga kestabilan bangunan di bawah permukaan tanah. Konstruksi dinding penahan tanah dipilih berdasarkan kedalaman galian, jenis tanah, ketinggian Muka Air Tanah (MAT), dan beban yang ditahan. Metode perhitungan gaya lateral menggunakan teori Rankine dan Coulomb dengan parameter-parameter tanah yang ditentukan. Studi kasus dilakukan pada area seawater intake PLTU Jawa 9 & 10 Suralaya di Suralaya, Cilegon, Banten. Proses perancangan melibatkan interpretasi data tanah, penentuan kelas situs, dan analisis stabilitas menggunakan perangkat lunak MIDAS GTS NX. Desain dinding penahan tanah dibagi menjadi dua bagian, dengan menggunakan dinding diafragma dan secant pile. Penggunaan perkuatan lateral berupa angkur tanah disesuaikan dengan ketentuan SNI 8460-2017. Hasil perancangan menunjukkan konfigurasi dinding dan angkur yang memenuhi kriteria desain, dengan nilai angka keamanan dan defleksi lateral yang sesuai. Meskipun demikian, pemilihan model tanah Mohr-Coulomb dan analisis gempa pseudostatik menghasilkan hasil yang lebih konservatif. Kesimpulannya, desain dinding penahan tanah terbukti efektif dalam menangani beban dan tekanan lateral tanah pada proyek seawater intake PLTU