No abstract

The western region of Sumatra Island is an area located on the world's active plate margin, which is reflected by the high frequency of earthquake events. An effort to reduce the impact of the earthquake disaster is to conduct a seismic hazard analysis. There have been many studies on seismic hazard in the West Sumatra region. Still, in the surrounding areas such as Riau, which borders directly with the territory, there has never been an earthquake hazard mapping micro zonation. This study aims to determine the value of surface acceleration for various districts or cities in Riau Province, by knowing the amount of surface acceleration, it will be able to identify the areas that have a relatively high level of earthquake risk. The Surface acceleration analysis is done by using the probabilistic Seismic hazard method (PSHA) using The SR Model software. The results of this study are obtained from 12 districts or cities located in Riau in which three areas have a high value of surface acceleration, those are Rokan Hulu regency, Kampar regency), and Kuantan Singingi regency). The amount of surface acceleration in Riau province in the 0.0 second period or peak ground acceleration (PGA) is in the range 0.097 -0.78 g, then in the 0.2 second period the surface acceleration is in the range 0.204 -1.943 g, and in the 1 second period of the surface acceleration is in the range 0.176 -1.155 g.

Spatial planning has an important role in disaster mitigation efforts. The availability of earthquake maps is very useful in spatial planning. The need for spatial planning today is micro spatial planning. Therefore, the 2017 national earthquake map needs to be detailed into a micro zonation map at the district or city scale. The ground acceleration presented in the national earthquake map was the acceleration at bedrock, while in spatial planning it is the necessary acceleration at the surface. Therefore, the purpose of this research was to obtain a map of the earthquake at the surface with a micro-scale. Determination of the acceleration value at the surface was carried out by two models. Model-1, the surface acceleration was obtained by multiplying the results of the PSHA analysis at bedrock by the amplification factor based on SNI-1726. While Model-2, the acceleration value at the surface was directly obtained from the results of PSHA analysis using the average surface shear wave velocity (Vs30) based on data from the USGS. The result of this study showed that from the 2 analytical models used, Model-2 has a higher surface acceleration value than Model-1. Riau Province has 12 districts. in general, the 12 districts were included in the low to moderate risk index class, but there was one district that was close to the high index class, namely Rokan Hulu district.

A construction project has several factors that affect the success of a project. One of the factors was an optimal project’s cash flow. Optimizing cash flow of a construction project can be done by making several cash flow plans, and choosing the best one considering appropriate project’s time and cost constraints. The purpose of this study is to obtain an optimal cash flow plan on a construction project  using a capital loan from Sharia Bank.This research will be carried out on a specific project which is Construction and Rehabilitation Project of Government Health Service Building, District of Gunungkidul. In this study, the method used to analyze data is to make several project cash flow based on “Earliest Start” scheme by determining the duration for each activity and creating a network diagram using the Precedence Diagram Method (PDM). The final step is analysing the cash flow by calculating negative overdraft for each cash flow plan to determine the amount of capital loan from Sharia Bank and then comparing profits to obtain the optimal one.Analysis and discussion reveal that on the system of given Down Payment, and Project’s Termyn 50%, 75% and 100%, and a loan from Sharia Bank it is found that the optimum cash flow will make profit of 7.49%. Keywords: Cash Flow, Earliest Start (ES), Optimal Profit, Sharia Bank.AbstrakProyek konstruksi memiliki beberapa faktor yang mempengaruhi kelancaran proyek tersebut, salah satu yang mempengaruhi proyek tersebut adalah cash flow optimal. Optimalisasi cash flow suatu proyek konstruksi dapat dilakukan dengan membuat rencana cash flow secara tepat dari suatu proyek. Tujuan penelitian ini adalah mendapatkan rencana cash flow optimal pada proyek konstruksi dengan menggunakan sumber modal bank syariah.Obyek penelitian akan dilakukan pada proyek Pembangunan dan Rehabilitasi Gedung Pelayanan Kesehatan Pemerintah Kab. Gunungkidul. Pada penelitian ini dalam analisis data dibuat rencana cash flow proyek dengan menentukan durasi untuk setiap kegiatan dan membuat diagram jaringan kerja earliest start menggunakan metode Precedence Diagram Method (PDM) dengan bantuan software microsoft. Langkah terakhir adalah analisis cash flow dengan menentukan overdrat negatif pada rencana cash flow untuk menentukan nominal pinjaman dengan menggunakan sumber modal bank syariah lalu membandingan keuntungan untuk mendapatkan profit optimal.Hasil analisis cash flow dan pembahasan didapat beberapa kesimpulan yaitu pada sistem pembayaran uang muka, termin 50%, termin 75% dan termin 100% dari owner serta menggunakan pendanaan bank syariah didapatkan cash flow optimal pada kondisi penjadwalan earliest start dengan persentase profit sebesar 7,49%. Kata kunci: Cash Flow, Earliest Start (ES), Optimal Profit, Bank Syariah.

Saat ini, tandon air beton dengan metode "cor di tempat" masih menggunakan teknologi konvensional dan memakan waktu konstruksi yang lama. Pada penelitian ini dilakukan kebaruan melalui inovasi tandon air beton dengan metode "pracetak" sesuai karakteristik teknis SNI dan harga yang mampu untuk menembus pasar. Tahapan penelitian dimulai dengan investigasi ke pabrik pembuatan tandon air beton dan dilanjutkan dengan pengujian karakteristik material penyusun beton dan panel-panel pracetak dengan beberapa variasi diameter besi tulangan sebagai perkuatan. Kekuatan struktur diuji terhadap kuat desak dan kuat lentur. Penentuan diameter besi tulangan dilakukan dengan optimasi agar tandon air ini aman untuk diletakkan di bawah tanah yang berada di bawah garasi mobil keluarga. Kemudian, studi kelayakan ekonomi dilakukan melalui perhitungan harga pokok produksi, yang kemudian dibandingkan dengan harga pasaran melalui survei. Hasil penelitian menunjukkan bahwa panel pracetak sesuai standar SNI memiliki kuat desak beton rata-rata 25,8 MPa dan kuat lentur terendah 157,23 kg.m pada perkuatan dengan besi anyaman 2,6 mm. Tandon ini aman untuk diletakkan di bawah garasi mobil keluarga dengan faktor aman sebesar 187%.