Comparison of fly ash with Lapindo mud as a land stabilizer for landfill in Pasuruan–Indonesia

Abstract

Waste generated by human activities in the form of industrial waste or household waste is collected in a certain area called the final waste disposal site (TPA). Waste that has accumulated over the years with a large volume will undergo a decomposition process aerobically or anaerobically due to the activity of microorganisms [1, 2]. The decomposition process will produce leachate water containing chemical elements, which can reduce soil quality. The soil in the landfill site is a mixture of the original soil in that location with waste that has been decomposed by the activity of microorganisms. Because of this formation process, the soil in the landfill site is included in the classification of organic soil [3]. Such soil conditions are less favorable for the land as a support for the construction of the building on it if one day the location is used for construction. Therefore, it is necessary to improve or stabilize the soil first. Efforts to improve the bearing capacity of the soil have been carried out in various ways, including mechanical, chemical, and even special technology. Mechanical soil improvement is carried out by replacing the original soil with other soil that has better mechanical properties, while chemical soil improvement is carried out by adding or mixing stabilizing agents into the original soil [4]. In any civil engineering work, the most important aspect is land. Some of the problems that are often encountered are because the soil’s poor technical properties are characterized by excessive groundwater, large compatibility and low bearing capacity. Some soils have significant volume changes along with changes in water content. One of the types of soil that have poor physical and mechanical properties is landfill, which has been used as an urban waste landfill (TPA) [5]. The landfill is a former landfill that is more than 20 years old. As a result of the activity of microorganisms, the waste will undergo a decomposition process aerobically or anaerobically. The landfill is a mixture of the original soil of the area, decomposed waste, and soil that is used to cover each layer of waste [6]. Such soil conditions are less favourable for the land as a support for the construction of the building above it if one day the location is used for construction. Therefore, it is necessary to improve or stabilize the soil first. Lapindo mud flow is an incident where hot mud spurts at the drilling location of PT. Lapindo Brantas Inc in Balongnongo Hamlet, Renokenogo Village, Porong District, Sidoarjo Regency. The chemical composition possessed by How to Cite: Sudjianto, A. T., Halim, A., Gembiranto, O., Susilo, S. H. (2021). Comparison of fly ash with lapindo mud as a land