Aplikasi Metode Seismik Refraksi untuk Identifikasi Pergerakan Tanah di Perumahan Balaroa Palu

Telah dilakukan penelitian dengan mengidentifikasi pergerakan tanah di Perumnas Balaroa Palu, melalui aplikasi Metode Seismik Refraksi.  Berdasarkan hasil pengukuran, diperoleh data berupa rekaman gambar penjalaran gelombang seismik yang diolah menggunakan Software Pickwin dan Plotrefa. Pengolahan data tersebut menghasilkan grafik traveltime dan penampang seismik 2D dengan 3 lapisan, yang menggambarkan lapisan struktur bawah permukaan lokasi penelitian. Lapisan pertama diketahui kecepatan gelombang  berturut-turut adalah 330 m/s, 396 m/s, 460 m/s dan 380 m/s yang diinterpretasikan sebagai pasir kering. Untuk lapisan kedua kecepatan gelombang berturut-turut 561 m/s, 587 m/s dan 980 m/s, diinterpretasikan sebagai pasir kering, sedangkan untuk lapisan ketiga kecepatannya berturutturut adalah 760 m/s, 592 m/s, 960 m/s dan 1800 m/s, yang diinterpretasikan sebagai lempung. Bidang gelincir penyebab terjadinya pergerakan tanah, diinterpretasikan berada pada lapisan kedua dan lapisan ketiga.</jats:p

Analysis of shear wave velocity on rocks using microtremor refraction method (ReMi) in Watatu Village, South of Banawa, Donggala Regency

Abstract The analysis of shear wave velocity on rocks in Watatu, South of Banawa, Donggala Regency using Microtremor Refraction Method (ReMi) has been conducted. The purpose of this research is to analyze the propagation velocity of shear wave on rocks layers up to 30 m in depth and to know the type of rock layer profiles in the study location. The method used was Microtremor Refraction using Surface Wave Analysis Wizard software and WaveEq software. The results showed that the rocks of trajectory 1 and trajectory 3 were classified into type E soft soil type with the respective including Vs30 values of 127.8 m/s for trajectory 1 and 98.9 m/s for trajectory 3. Then for trajectory 2 and trajectory 4 are classified into D type rocks i.e medium soil types with Vs30 values respectively on Track 2 of 235.1 m / s and for Lane 4 of 196.9 m/s.</jats:p

Estimation of ordinary kriging parameters for determining characteristics and distribution of groundwater layer in Tondo area, Mantikulore district, Palu

Abstract Tondo area as a research location is one of Palu area. The topography of this area besides sloping and interspersed with hilly areas is also a barren and critical groundwater area. Geologically, the rock structure that comprises this area consists of Molasa Celebes deposits namely clay, sand and gravel. So far, clean water in the Tondo area has been supplied by the Palu City Regional Drinking Water Company (PDAM) from the surface water source in Kawatuna area. There is also a PDAM Donggala that supplies clean water to this area which is sourced from groundwater. However, the water source is quite deep at around 150 m besides that the depth of groundwater position varies based on the results of groundwater drilling in this region and groundwater cannot always be found. If these results are followed up with Ordinary Kriging research using a Semivariogram to find groundwater, the results are expected to be better and more accurate. Based on the research results obtained that: The best model is the Spherical model with the smallest MSE value of 429.5016 and the resulting parameter values are nuggets = 15.70937, sill = 28.46195, and range = 3343.121. The deepest depth is 23.07785 m.</jats:p

Identification of distribution changes of leachate in a landfill

Abstract The distribution of leachate in the Kawatuna landfill, Palu City, which is still implementing the Open Damping system, has been researched in 2011 where it was detected up to a depth of 7 meters and led to reservoir of leachate. The Landfill Control system has been implemented, but the leachate pipe was not functioning, and part of the storage pool was damaged during the earthquake on September 28, 2018, so that leachate is scattered everywhere. This study aims to determine changes in the distribution of leachate used geoelectric-resistivity method with Wenner-Schlumberger configuration. Data were collected at 3 points within the landfill site and 1 point outside the location, with a length of 48 meters each and processed using EarthImager 2D software. From the research results, it is obtained that the resistivity value of leachate is 1–9.7 ohmmeter. Based on the cross-sectional resistivity analysis, leachate was spread to a depth of 9.7 m, which indicates an increase depth of 2.7 m and the distribution direction was not leading to reservoirs of leachate</jats:p