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PENGARUH TEGANGAN AIR PORI NEGATIF TERHADAP KUAT GESER TANAH LEMPUNG Robby Nikolus
Jurnal Teknologi Berkelanjutan Vol 1 No 02 (2012): Vol 01 No. 02
Publisher : Lambung Mangkurat University Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (527.362 KB)

Abstract

Soil in the sampling area undergoes drying-wetting cycle in therainy season and the dry season. This could make pore water in the soilto fluctuate so that the suction changes. The experiment used no.42 Whatman paper filter to measure suction and direct shear test to measure the shear strength.No. 42 Whatman paper filter was placed in the sample inside a pvc tube. It took three variatons of water content. The first variation was wetting variation. Sample was given water so that the water content increase to 25%, 30% and 35%. The second variation was drying variation. Sample was stored in a desicator filled silica gel, so that water content decreased to 15%, 10%, 5% and 0%. The third variation was wetting-drying variation. Sample at maximum water content (35%) was dried gradually so that water content decreased to 30%, 25%, 15%, 10%, 5% and 0%. This experiment indicates that increasing and decreasing suction results in the variation of the shear strength and the volume soil. Variation in the soil volume is the alteration of void ratio (e), degree of saturation (Sr) and water content (w). The result during the wetting procces or rainy season, the soil shear strength will decrease along with decreasing suction. In drying procces or dry season, the soil shear strength will increase along with increasing suction.
Quality Control Batubara Dari Channel-pit Menuju Rom Stockpile di PT Mega Multi Energi Suratno; Nurul Wahidah; Robby Nikolus
Journal Scientific of Mandalika (JSM) e-ISSN 2745-5955 | p-ISSN 2809-0543 Vol. 6 No. 4 (2025)
Publisher : Institut Penelitian dan Pengembangan Mandalika Indonesia (IP2MI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36312/10.36312/vol6iss4pp904-916

Abstract

In processing existing data by analyzing the situation in the field from primary and secondary data. For primary data such as field observations, and coal sampling data and secondary data in the form of research location maps and laboratory test results, where the results of the coal quality laboratory test produced proximate analysis data with parameters of total moisture, inherent moisture, ash contant, volatile matter, fixed carbon, total sulphure and calorific value. In statistics, regression analysis is often used to test the relationship between an independent variable and a bound variable. The mathematical model that states the relationship between the two variables is called a regression equation. From the results of the comparison of coal quality with the parameters of proximate analysis, there was a change in coal quality at the time of the front towards the stockpile, which was as follows: TM = 0.68 %, IM = 0.61%, ASH = --1.32%, VM = 3.28 %, FC = 2.31 %, TS = -0.27 %, CV = -174 Kcal/kg. From the results of the analysis, it is known that the largest influence of the parameters that cause the decrease in calories is ash content of 36.69%, total moisture of 22.6%, volatile matter of 64.19%, inherent moisture of 27.5%, fixed carbon of 25.87%, and total sulfur of 0.44%.