Exploring The Mechanism Of Vetiver System For Slope Reinforcement On Diverse Soil Types – A Review

Landslide, one of the important geomorphological processes, is essentially a natural phenomenon that is often exacerbated by human-induced activities. A stable sloping terrain will tend to collapse when it is subjected to forces that tend to destabilise it. Slope instability is one of the main factors leading to disasters that might be catastrophic to the environment and human life. Since the beginning of the year 2000 only, thousands of fatalities annually occurred globally due to landslides. With its predominantly sloping topography, the landslide is also a frequent natural disaster in Indonesia. BNPB data stated that between 2013 and 2022, there were 7,297 recorded cases of landslides in the country with more than 100 casualties on one occasion. To mitigate the impact of this disaster, measures such as reinforcing slopes or implementing retaining walls in vulnerable areas are urgently required. In recent decades, bio-engineering techniques gain more attention in slope reinforcement by combining the mechanical and hydrological abilities of vegetation in erosion control and slope stabilisation. Vetiver grass is one of the vegetation species used in bioengineering techniques due to its low cost and more sustainable solutions in many infrastructure projects. In this paper, a qualitative literature review is conducted and processed using descriptive-analytical methods to address the mitigation of landslides and their potential domino effects on the economy and people's welfare

Experimental Study Of Improving The Physical Properties Of Peat Soil Using Sand And Bio-Grouting Techniques With The Assistance Of Bacillus Subtilis Bacteria

Peat soil was categorized as soft soil, which means that the soil is in bad condition and problematic when construction was built on it. It was necessary to increase the carrying capacity of peat soils, one of which is chemical stabilization of the soil, by adding additives that can react with the soil and using new environmentally friendly methods. In this study, samples of peat soil were taken from Buana Makmur Village km55, Dayun District, Siak Regency. The stabilizing agent used was sand as much as 5% by weight of dry soil, Bacillus Subtilis bacteria obtained from the Agriculture Laboratory of the Islamic University of Riau, and also CaCL₂ and Urea. The method for stabilizing the physical properties of peat soil in this study is the Bio-Grouting method, testing the physical properties of peat soil follows the procedures of ASTM (American Society For Testing And Materials) and SNI 1965-2008 for testing methods for determining water content for soil and rock in the laboratory. SNI 1964-2008 test method for soil specific gravity, SNI 8460-2017 geotechnical design requirements, SK SNI -04-05-1989-F fine sand used for construction, SNI-02-2801-1998 urea standard. To test the physical properties was carried out by providing variations in the mixing of bacterial cementation solutions with levels of 0% (without treatment), 5%, 10%, 15%, 20%, and 25% and then allowed to stand for 14 days using a tightly closed plastic container. The results of testing the physical properties of peat soil found that the peat soil was included in the original soil type with water content = 407.45% and specific gravity (Gs) = 1.30gr, while from the physical properties tests carried out the highest water content occurred in the addition of bacterial cementation solution 10% = 177.2% and the lowest specific gravity occurs when the bacterial cementation solution is added 10% = 1.27gr

Economic Evaluation Of Water Production Management With Rpm (Relative Permability Modifier) Treatment Based On Gross Split Contract In “Re” Well In “Dn" Field

The "RE" well in the "DN" field is an oil well produced in June 2004 with an initial water cut value of 15% as time went on there was a fairly high increase in the water cut value reaching 97% which means that it caused increased water production. and oil production decreased from 387 BOPD to 11 BOPD. Appropriate handling in overcoming excessive water production, one of which is by using a method that can selectively restrain water production without restraining hydrocarbon production with RPM (Relative Permeability Modifier) ​​Treatment. RPM (Relative Permeability Modifier) ​​is a type of polymer with a high molecular weight as the main molecule of RPM. RPM can be done without isolating the layer zone so that it can be injected bullhead into all layer zones to reduce water permeability. This final project research has been seen from increasing the rate of oil production and decreasing the water cut. The selected well is the "RE" well in the "DN" field which has an increasing water cut value and decreased oil production. Then calculate the economy using the gross split method to calculate the feasibility level of the RPM (Relative Permeability Modifier) ​​Treatment project. &nbsp

Electrical Resistance Tomographic by Using Current Injection and Magnetic Field Induction

A critical issue in electrical tomography is ill-posed problems due to low sensitivity. In the electric current injection method, the placement of the injection electrode on the object boundary can influence it. This condition causes the reconstruction result of parameter change far away from the boundary to be inferior in quality. Another excitation method is using magnetic field induction proposed to overcome these problems. Each reconstruction image was obtained using two methods with three types of parameter changes, that represented the edge and the center of the object position. Both reconstruction results are merged and further processed to enhance the quality of the image, based on the average value of the resistivity of each element. The results show that the final image reconstruction has a smaller root mean square error (RMSE) than the electric current injection method

Back matter JGEET Vol 08 No 02 2023

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Study of Boalemo Red Limestone for Geotourism Development based on Lithological, Geochemical Analysis and Geological Heritage Assessment

Indonesia has very diverse and unique rocks that have the potential to become a geological heritage. Based on the existing potential, an integrated management system is needed so that it can be utilized for the welfare of the community, one of which is a geopark. Gorontalo has a rock distribution consisting of several formations, one of which is the Tinombo Formation which is the oldest formation.  In this formation there is red limestone which has great potential due to its rarity so that it can be developed into a site in the development of a geopark in Gorontalo. The purpose of this research is to conduct a geosite assessment of geological features in Boalemo Regency as a basis for developing geotourism in Boalemo Regency, Gorontalo. The research site is located in Dimito Village, Wonosari Subdistrict and Lahumbo Village, Tilamuta Subdistrict, Boalemo Regency, Gorontalo Province. The methods used in this research are lithological analysis, Geochemical analysis and geosite potential analysis using the technical guidelines for geological heritage resource assessment by the Geological Survey Center. The results showed that the red color-controlling minerals in limestone are hematite and rodoxite, the red color-controlling chemical elements in limestone are SiO2, MnO, Fe2O3, Sr and CaO. The results of the assessment of geological features explain that the Wonosari Red Limestone Site and the Tilamuta Red Limestone Site are included in the medium category. Geosite Red Limestone can be developed as an object of study in the field of education by utilizing natural laboratories for the development of geoparks in Gorontalo

Study of Hydrodynamic Patterns of Tanjung Pasir Banten Waters to Support the NCICD Sea Wall Development Plan

Numerical modeling of hydrodynamics (HD) around the Tanjung Pasir Waters was carried out using MIKE 21 HD Flexible Mesh software to get the current velocity pattern conditions during the west and east monsoons. This activity is to support the NCICD sea wall construction plan. In addition, the results that will be obtained in this modeling are the conditions of the speed and direction of the current in various tidal conditions during spring and neap. The data used in this modeling include wind speed and direction, wave height, wave period, and wave direction. Based on the research that has been done, the validation value of Naotide tidal data on tidal field data is 93.8 %. HD MIKE 21 modeling results on field data have a validation value of 93.4 %. Extract points 4 and 5 which are the northernmost, have the highest current velocity values compared to the other points. In addition, when heading to the high tide phase, both spring and neap conditions, the current velocity value has the highest value

Analysis of Petrophysical Parameter on Shaly Sand Reservoir by Comparing Conventional Method and Shaly Sand Method in Vulcan Subbasin, Northwest Australia

Vulcan Subbasin is an area with a lot of oil and gas exploration where is located in the Bonaparte Basin, Northwest Australia. There is some formation identified as sandstone reservoir with clay content which is usually called shaly sand based on the screening between resistivity log and density log. Clay content caused lower resistivity log readings so the shaly sand reservoir is considered as non-reservoir. To overcome this, a method besides the conventional method was applied to analyze the petrophysical parameters of shaly sand reservoir, it was shaly sand method. Petrophysical analysis is an analysis of rock physical parameters such as shale volume, porosity, and water saturation based on well log data. In this study, petrophysical analysis was carried out in the Vulcan Subbasin using 35 well log data, including gamma ray log, resistivity log, neutron log, and density log for the conventional method and shaly sand method involved Stieber equation and Thomas Stieber plot. The results obtained from this study are the comparison of petrophysical parameter values and pay summary between the conventional method and the shaly sand method, also its relation to the shale distribution type. By applying the shaly sand method, the average shale volume has decreased, the average porosity has increased, the average water saturation has increased, the average net to gross has increased, the average net thickness has increased, and the average net pay has increased. Changes in the average value were caused by laminated-dispersed shale distribution type which is influenced by diagenesis and the depositional environment of the formation

Back matter JGEET Vol 08 No 01 2023

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Analysis of Land Subsidence in Peatlands in the Awareness Area of Pekanbaru, Riau, Indonesia

This study area is administratively located in Parit Indah District, Bukit Raya District, Pekanbaru City, Riau Province. Geographically, the research area is located at coordinates 0° 28' 30.92" N 101° 28' 9.45" E N 0° 27' 25.63" - 101° 29' 47.30" E. The aim of this study was to find out the effect of peat soil types on subsidence. The data collection method in this study was carried out using sieve analysis, water content analysis, specific gravity, subsidence analysis, and soil testing in the laboratory. The effect of peat soil on subsidence has a significant effect between the type of peat and subsidence, the higher the maturity level of the peat, the lower the level of subsidence on peat soil. Based on the results of the study, the soil consolidation test with a depth of 75cm-3m had a soil settlement value of 0.467. It is recommended to do this to reduce the impact of subsidence in the land area such as the research area so that it does not have too much impact on the construction which is carried out by hardening the location using the vertical wick drain method, as well as for building foundations it can be done using chicken claw foundation