CHAPTER 1IntroductionBackgroundSoil is the common material used as the base or foundation for every construction and it must first be compacted. This is because the soil used contains high air voids. Air gaps occur when there is air trapped between soil particles. High air void content in the soil will decrease the strength of the soil and the soil is classified as soft soil. To eliminate air voids, mechanical energy is required and indirectly it will also cause changes in water content. Compaction is the process of making soil denser. This is where soil particles are pressed against each other while pushing air out of the soil in the process. Compaction will improve the technical properties of the soil. This is because the soil that compresses will have a higher resistance due to the narrower position of the particles. Additionally, the compressibility and permeability of the soil will decrease. Figure 1: Soil characteristics such as density and unit weight will increase due to the expulsion of air during the compaction process. The terms density and unit weight are often used incorrectly. Density refers to the amount of mass per unit volume (kg⁄m^3) and the symbol for density is ρ. On the other hand, unit weight refers to the weight per unit volume (kN⁄m^3) and the symbol for unit weight is γ.Figure 2: Each soil has different characteristics regarding maximum density and l 'optimum. humidity. Soil types are generally determined by grain size. Therefore, it can be classified by performing a sieve analysis test to determine the size of soil particles passing through the series of sieves to filter or separate different grain sizes...... middle of paper .. ....s compressed several times on each layer during the construction process, but the probability that sand will settle still exists, as so often happens when depositing soil in the abutment and embankment. This is likely due to vibrations and loads repeatedly applied to the ground from its surroundings. Therefore, the compaction test will be carried out in the laboratory by applying the same concept that the sand in the mold will be compacted and vibrated using the variable methods. soil compaction so that the soil experiences the same situation as during construction work. The results of these tests will be compared. The study is to determine which method of soil compaction is more effective in terms of the method of compacting the soil particles closer by referring to the difference in the volume of sand in the mold before and after the compaction test carried out.