THE STUDY EFFECT OF MICROORGANISM ADDITION TO THE CHARACTERISTIC PROPERTIES AND SHEAR STRENGTH OF PALEMBANG PEAT SOIL

• Main Author: A Niar Nauri Ningsih, R
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/36917
• Institution: Institut Teknologi Bandung

Geotechnical peat soils include problematic soils because they have low shear strength and high compressibility. The presence of fibers in peat soil shows that the decomposition process that occurs in peat soils is still quite low. This can be caused by a lack of microorganisms contained in peat soil. Therefore, the study of the effect of the addition of microorganisms in the form of Bios 44 was carried out to improve the decomposition process so that the strength of peat soil increased and peatlands especially on the island of Sumatra could be utilized effectively. This thesis contains an experimental study of the effect of adding Bios 44 mixture with a percentage of 5%, 10%, and 15% with two conditions, namely without ripening and ripening for 7 days. Testing of mixed peat soil samples is carried out according to ASTM (American Standard Testing Material) standards. Peat soil engineering properties observed included analysis of specific gravity, pH value, ash content, organic content, fiber content, compacting using the Standard Proctor Compaction Test, and shear strength with Triaxial CU testing. The peat soil in this study originated from Banyu Urip Village III, Palembang visually has a solid black color and contains fiber and organic and high ash, and has high carbon and oxygen elements. Bios 44 is an ingredient that contains microorganisms and alkaline elements in the form of calcium. If the peat and Bios 44 are mixed, it will cause a reaction of CaCO3 (lime) which causes increased strength of peat soil. In this study the design of the test object was carried out in accordance with the optimum water content and compaction dry weight of each percentage of the addition of Bios 44 to peat soils according to the results of the Palembang peat soil compaction test. The results showed that the effect of the addition of Bios 44 on physical characteristics and shear strength among others: increasing the value of specific gravity, pH and ash content, reducing the value of organic content and fiber content, increasing the value of peat soil parameters (cohesion (c), internal friction angle ( ?), effective soil cohesion (c '), effective internal friction angle (?')), increase the Undrained shear strength (Su) and effective shear strength (? '), and increase the failure parameter values (M and q0) on the graph Stress Path Palembang peat soil. Based on the analysis of the research, Palembang peat soil tend to behave like Normally Consolidated. This is because the historical stress of the test sample before consolidation is smaller than the given confining pressure. The value of the consolidation pressure of natural peat soil is 38 kPa. In the Triaxial CU test the compining pressure is 50 kPa, 100 kPa and 200 kPa. The addition of Bios 44 to peat soil has the effect of increasing the value of the deviator stress to reach collapse and pore water pressure reading also increases with increasing Bios percentage and given cell stress, and increases the soil collapse parameter value which also increases the shear strength parameter of Palembang peat soil. Keywords : Peat, Microorganism, Bios 44, ASTM, Normally Consolidated, Cohesion, Internal Friction Angle, Effective Cohesion, Effective Internal Friction Angle, Undrained Shear Strength (Su), Effective Shear Strength, Stress Path.