Proposed New Strong Ground Motion Attenuation Relations for Subduction Zone Earthquakes

. This paper present proposed new attenuation relations at rock sites for peak ground acceleration for subduction zone interface and intraslab earthquakes of moment magnitude M 5 and greater and for distance of 10 to 500 km. The relations were developed by Artificial Neural Networks (ANN) approach using a back propagation algorithm. Studies show that the ANN-based attenuation relation is reliable and accurate to predict peak ground acceleration (PGA) due to earthquakes. Parameters studies of the various input factors of attenuation relations were also performed in this study and its results will be presented in this paper

An Overview of Soil Models for Earthquake Response Analysis

Earthquakes can damage thousands of buildings and infrastructure as well as cause the loss of thousands of lives. During an earthquake, the damage to buildings is mostly caused by the effect of local soil conditions. Depending on the soil type, the earthquake waves propagating from the epicenter to the ground surface will result in various behaviors of the soil. Several studies have been conducted to accurately obtain the soil response during an earthquake. The soil model used must be able to characterize the stress-strain behavior of the soil during the earthquake. This paper compares equivalent linear and nonlinear soil model responses. Analysis was performed on two soil types, Site Class D and Site Class E. An equivalent linear soil model leads to a constant value of shear modulus, while in a nonlinear soil model, the shear modulus changes constantly,depending on the stress level, and shows inelastic behavior. The results from a comparison of  both soil  models  are  displayed in the form of maximum acceleration profiles and stress-strain curves

SISTEM MONITORING KETINGGIAN OMBAK AIR LAUT SECARA REAL-TIME BERBASIS IoT

Indonesia is an archipelagic country where most of its territory is water, so all activities carried out in water, especially the sea, are an important part of the life of the Indonesian people. The height of the sea waves is a phenomenon that greatly affects the efficiency and safety of people when they are in sea waters. The process of obtaining sea wave height data requires an appropriate system. So this study designed a prototype system for monitoring the height of sea waves in real-time based on IoT. The method used is the waterfall, where the ultrasonic sensor will be connected to the ESP-8266 nodemcu so that real-time sea wave height data is obtained through the user interface on the Thinger IO Platform. In addition, the system uses red, yellow, and green LEDs as indicators of the height of the water waves. These results indicate that the application of real-time IoT-based sea wave height systems has good capabilities. This is indicated by the user being able to see real-time monitoring data on sea wave height based on IoT with the display of numbers, graphs, and LED indicator lights. For the seawater level scale used in the system, the LED indicator lights in red are 0-10 cm,yellow are 11-20 cm, and green are 21-30 cm

PENGARUH FREKUENSI PEMBILASAN FILTER ARANG AKTIF BATOK KELAPA DAN SPONS PADA SISTEM RESIRKULASI TERHADAP KUALITAS AIR MEDIA PEMELIHARAAN IKAN MAANVIS (Pterophyllum Scalare)

ABSTRACTThe frequency of flushing on coconut charcoal and sponge filters by Recirculation Aquaculture System (RAS) can apply to maintain water quality. This research was conducted on Laboratorium Dasar Perikanan, Department of Aquaculture, Faculty of Agriculture, Sriwijaya University from March to May 2017. The study used Completely Randomized Design with 4 treatments and 3 replications. The treatment were using filter flushing every week (P1), 2 weeks (P2), 3 weeks (P3) and without leaching (P4). The parameters observed were temperature, pH, dissolved oxygen (DO), turbidity, total dissolved solids (TDS) and ammonia. The results showed that the flushingfrequency gave of the filter has a positive effect on water quality parameters. Treatment P2 has resulting better water quality such as temperature (28.3-29.2), pH (6.9-7.2), DO (1.11 mg.L-1), Turbidity (0.00 NTU), TDS (22.33 mg.L-1), ammonia (0.020 mg.L-1), survival rate 83.33%, absolute growth (0.93 cm for lenght and 0.58 g for weight). Keywords: flushing of filter, resirculation system, water quality, angelfis

Analisis faktor keikutsertaan screening hepatitis “B” pada ibu hamil

Background: Nagan Raya Regency is included in the top 5 districts/cities with the fourth highest number of hepatitis in Aceh Province. The hepatitis B screening program has not been implemented properly. The impact of the low coverage of this program affects public ignorance about the spread of hepatitis B from sufferers to other communities.Objective: This study aims to analyze the participation factors for Hepatitis B screening in pregnant women in the working area of the Ujong Patihah Health Center.Method: This research design is cross sectional study, in 2021. Data were collected using a questionnaire with a sample size of 220 pregnant women. Data collection was carried out by direct interviews with respondents, using a questionnaire instrument. Data analysis used the Cgi-square statistical test with a significance level of 95%, and continued with multivariate analysis using the Binary Logistics Regression test.Results: Bivariate analysis showed that there was a relationship between knowledge (p= 0.022), mother's attitude (p= 0.010), husband's role (p = 0.018), role of health workers (p = 0.028) and participation in hepatitis B screening, while education did not affect participation in hepatitis B screening (p= 0.668). Multivariate results showed that the mother's attitude was the dominant factor for participation in hepatitis B screening (OR= 2.24).Conclusion: Positive attitudes had a 2.24 times relationship to the participation of pregnant women in hepatitis B screening than negative attitudes.

Proposed New Strong Ground Motion Attenuation Relations for Subduction Zone Earthquakes

Abstrak. Tulisan ini menyajikan usulan fungsi atenuasi terbaru untuk percepatan maksimum gempa di permukaan tanah tipe gempa subduksi interface dan intraslab pada moment magnitude lebih besar sama dengan 5 dan jarak 10 km sampai 500 km di batuan. Fungsi atenuasi telah dikembangkan dengan pendekatan Jaringan Syaraf Tiruan (JST) menggunakan algoritma propagasi balik. Studi memperlihatkan bahwa fungsi atenuasi berdasarkan JST akurat dan andal untuk memprediksi percepatan maksimum gempa. Studi parameter berbagai faktor input dari fungsi atenuasi juga telah dilakukan dan hasilnya akan disajikan di dalam tulisan ini.Abstract. This paper present proposed new attenuation relations at rock sites for peak ground acceleration for subduction zone interface and intraslab earthquakes of moment magnitude M 5 and greater and for distance of 10 to 500 km. The relations were developed by Artificial Neural Networks (ANN) approach using a back propagation algorithm. Studies show that the ANN-based attenuation relation is reliable and accurate to predict peak ground acceleration (PGA) due to earthquakes. Parameters studies of the various input factors of attenuation relations were also performed in this study and its results will be presented in this paper

Development of Pre-consolidation Pressure Dependence of Mixed Hardening Multisurface Hyperplasticity Model for Better Prediction of Earthquakes Ground Response Analysis

Abstract. It was known that soil behavior is dependent upon the history of loading and exhibits hardening behavior when deformed plastically. This paper presents a formulation of mixed hardening multisurface hyperplasticity model with stiffness factors of the kinematic hardening of the yield surfaces proportional to the pre-consolidation pressure to represent the history of loading. Formulation is emphasized for describing the cyclic loading behavior of clay soils. The advantages of this approach are that it can reproduce smooth transitions from elastic to plastic behavior and allows the stress-reversal history to be memorized by the internal variable function. The Modified Cam Clay yield function is selected as a key model to simulate the stress-strain response. The incremental stress"“strain response is calculated based on a rate-dependent formulation. Finally, this paper describes the importance of development of the formulated soil model to improve current constitutive models for evaluating the effects of local soil conditions on earthquake ground response analysis. Further results of numerical implementation and simulations and also model verification employing the proposed mathematical model formulation will be reported in a future publication. Abstract. Telah diketahui bahwa perilaku tanah akan tergantung dari sejarah pembebanannya dan juga memperlihatkan perilaku hardening apabila tanah mengalami deformasi secara plastik. Tulisan ini menyajikan sebuah formulasi model tanah mixed hardening multisurface hyperplasticity dengan faktor kekakuan kinematik hardening proporsional terhadap tekanan pra-konsolidasi guna merepresentasikan sejarah pembebanan yang terjadi pada tanah. Formulasi ditekankan untuk mendeskripsikan perilaku pembebanan siklik pada tanah lempung. Kelebihan dari pendekatan model hyperplasticity ini adalah dapat menghasilkan transisi dari perilaku elastik ke plastik secara smooth serta mampu "mengingat" sejarah perubahan tegangan yang terjadi pada tanah dengan menggunakan fungsi variabel internal. Fungsi leleh Modified Cam Clay dipilih sebagai model utama untuk mensimulasikan respons tegangan-regangan. Selanjutnya, respons tegangan-regangan dihitung berdasarkan sebuah formulasi rate-dependent. Terakhir, tulisan ini mendeskripsikan pentingnya pengembangan model ini guna memperbaiki analisis respons tanah akibat gempa. Hasil-hasil lebih lanjut berupa implementasi dan simulasi numerik serta juga verifikasi model yang diusulkan akan disajikan dalam publikasi berikutnya

Finite Element Study of Vacuum Preloading and Prefabricated Vertical Drains Behavior for Soft Soil Improvement

AbstractFinite element modeling of soft soil improvement with prefabricated vertical drains (PVD) and vacuum preloading behavior was carried out by considering smear effect and equivalent plane strain based on permeability conversion. Transfer of negative pore pressure due to vacuum preloading was modeled by using pore pressure boundary condition at soft soil layer and along the length of the PVD. The soft soil layer was modeled by using Modified Cam Clay constitutive model. Effect of constant and linearly decreasing vacuum pressure along the PVD length was investigated. Furthermore, prediction from this modeling such settlement was compared to Terzaghi 1-D consolidation. Degree of consolidation for radial only and combined vertical radial were predicted by using Barron's and Carrillo's formula, respectively. Numerical evaluation of vacuum preloading-induced lateral deformation compared to conventional preloading was also presented including its comparation with analytical method. Finally, several conclusions and recommendations related to modeling and behavior of combined PVD and vacuum preloading was given.  AbstrakPemodelan elemen hingga perilaku perbaikan tanah lunak dengan vacuum preloading (pembebanan vakum) dan Prefabricated Vertical Drains (PVD) dilakukan dengan mempertimbangkan efek smear dan equivalent plane strain berdasarkan konversi permeabilitas. Transfer negative pore pressure akibat pembebanan vakum dimodelkan dengan menggunakan pore pressure boundary condition pada lapisan tanah lunak dan sepanjang PVD. Lapisan tanah lunak dimodelkan dengan menggunakan model konstitutif tanah Modified Cam Clay (MCC). Pengaruh distribusi tekanan vakum konstan dan bervariasi menurun secara linier di sepanjang PVD akan diteliti. Prediksi penurunan dari pemodelan elemen hingga selanjutnya dibandingkan dengan hasil perhitungan konsolidasi 1-D Terzaghi.  Derajat konsolidasi dihitung menggunakan persamaan Barron untuk arah radial dan Carrillo untuk kombinasi arah vertikal dan radial. Evaluasi numerik perilaku deformasi lateral akibat penggunaan pembebanan vakum dibandingkan dengan preloading (timbunan) juga disajikan berikut perbandingannya terhadap metode analitis. Terakhir, beberapa kesimpulan dan rekomendasi terkait pemodelan dan perilaku kombinasi PVD dan pembebanan vakum diberikan