COMPARISON OF STABILIZED SHEAR STRENGTH OF BLANGJERANGO CLAY AND SOME QUARRY SOILS WITH TRIPE JAYA GAYO LUES LIMESTONE ASH

Soil stabilization is a way that is most considered to be cheaper than replacing old, less good soil with better ones with the aim of improving the properties of the original soil which has low bearing capacity, high plasticity index, high swelling and poor gradation, especially for areas that requires soil improvement. One of the stabilizing materials that can be used is lime as an additive which is useful for increasing soil stiffness and strength. The lime used in this research came from Tripe Jaya District, Gayo Lues Regency. This research was carried out by taking soil samples in a quarry which was then added with lime as a stabilizing agent. This soil was tested for physical properties, compaction, and a shear strength test (direct shear). Research was conducted to see the results of soil stabilization with lime on changes in soil strength when receiving the effects of both natural and artificial (remolded) factors. The results of the research can be used to mitigate cases of road or building collapse on the subgrade or infrastructure built on the land. The primary data required in this research was taken from the results of examinations and tests in the laboratory. The tests and inspections carried out are in the form of measuring the physical properties of the soil such as water content, specific gravity, plastic limit, liquid limit, and PSA (Particle Size Analyzer), as well as measuring mechanical properties in the form of soil compaction parameters with a standard proctor on the original soil and soil shear strength using direct shear test to obtain friction angle ( ϕ ) and cohesion (c). In this research, a comparison of the stabilized shear strength of clay soil with Gayo Lues limestone has been carried out with several other soil sources for landslide analysis. The analysis results show that Gayo Lues limestone has a good ability to increase the strength and stability of clay soil. It is hoped that this research will provide useful information in selecting the right soil stabilization material.


INTRODUCTION
Soil stabilization is a way that is most considered to be cheaper than replacing old, less good soil with better ones with the aim of improving the properties of the original soil which has low bearing capacity, high plasticity index, high swelling and poor gradation, especially for areas that requires soil improvement.There are three types of soil used in this research originating from the land quarry area of Blangjerango District, Gayo Lues Regency, the land quarry at Lampoh Mamplan, Selimum District, Aceh Besar Regency and the land quarry at Paya Tumpi, Kebayakan District, Central Aceh Regency.One of the stabilizing materials that can be used is lime as an additive which is useful for increasing soil stiffness and strength.Lime has been known as a good soil stabilization material, especially for stabilizing clay soils which have large swellingshrinking properties and low bearing capacity.The presence of the Ca2+ cation element in lime can provide greater bonds between particles to combat swelling properties and increase the bearing capacity of the soil.This research was carried out by taking soil samples in a quarry which was then added with lime as a stabilizing agent.This soil was tested for physical properties, compaction, and a shear strength test (direct shear).Research was conducted to see the results of soil stabilization with lime on changes in soil strength when receiving the effects of both natural and artificial (remolded) factors.The results of the research can be used to mitigate cases of road or building collapse on the subgrade or infrastructure built on the land.

METHODOLOGY
This chapter discusses research methodology including data collection, data processing, procurement of materials and equipment, X-ray diffraction testing and chemical analysis, making test objects, measuring physical properties, compaction experiments, soil shear strength tests and data analysis.Testing was carried out at the Soil Mechanics Laboratory of the Civil Engineering Department of Lhokseumawe State Polytechnic based on the ASTM (American Society for Testing and Materials) method, X-Ray Diffraction (XRD) test and chemical analysis, and Scanning Electron Microscopy (SEM).

Data collection
The primary data required in this research was taken from the results of examinations and tests in the laboratory.The tests and inspections carried out are in the form of measuring the physical properties of the soil such as water content, specific gravity, plastic limit, liquid limit, and PSA (Particle Size Analyzer), as well as measuring mechanical properties in the form of soil compaction parameters with a standard proctor on the original soil and soil shear strength using direct shear tests to obtain the friction angle (ϕ) and cohesion (c).

Soil Sampling
In this researchThe samples taken were disturbed soil (disturbed samples), undisturbed soil (undisturbed samples), disturbed soil samples (disturbed samples) were taken by putting the soil into sacks with the help of a hoe and shovel.The soil is spread on the floor with a thick plastic mat and left for several days until the soil is air dry.Undisturbed soil samples are taken using a pipe that is inserted into the excavated or cleaned soil to a depth of about 10 cm.Then this sample is covered with wax and additionally covered with plastic paper tied with rubber, this is done so that the soil remains stable in terms of water content and other things.

Physical Properties Testing
Soil physical properties testing was carried out on three types of soil with variations in the addition of lime.Each soil physical properties test included specific gravity testing, grain distribution, and Atterberg limits which were guided by ASTM (American Society For Testing and Materials) standards.
Testing Atterberg's limits Atterberg limit testing includes liquid limit testing and plastic limit testing.The plasticity index is the value of the difference between the liquid limit and the plastic limit.The results of soil physical properties testing, compaction testing, shear strength parameter testing are recorded and analyzed.To make it easier to analyze a variable and the relationship between one variable and another, the research results are reported in the form of tables and graphs.Analysis was carried out with the help of a computer using the Microsoft Excel application.

Definition of Land
Soil is defined as material consisting of aggregates (grains) of solid minerals that are not cemented (chemically bound) to each other and of organic materials that have decayed (which are solid particles) accompanied by liquids and gases that fill the spaces.empty space between the solid particles (Das, 1991).In general, soil can be divided into two categories, namely cohesive soil and non-cohesive soil.Cohesive soil is soil whose physical properties always stick together and dry, these soil particles are bound to each other and therefore require force to separate in dry conditions, such as clay.Non-cohesive soil is layered particles after drying and will only stick together when wet due to the surface attraction of the grains in water, such as sandy soil (Bowles, 1993) Soil is a composition of three different phases.If the soil is partially saturated, it consists of three phases, namely solid particles, air pores and pore water, the equation for the volume-weight relationship of soil is obtained, with the formula as shown in equation 2.1 2) Where : vs = Volume of solid granules (cm 3 ); V.V = Pore volume (cm3); Vw = Volume of water in the pores (cm 3 ); Va = Air volume in the pore (cm 3 ).If air is considered to have no weight, then the total weight of the soil sample can be expressed by: W = Ws + Ww (2.3)Where : Ws = Weight of solid granules (gr); Wow = Weight of water (gr).If the soil is dry, the soil consists of two phases, namely solid particles and air pores.Completely saturated soil also consists of two phases, namely solid particles and pore water.Meanwhile, soil in a partially saturated state consists of three phases, namely solid particles, air pores and pore water.

Soil Physical Properties Water content
Water content (w) is the percentage ratio of the weight of water () with granular weight () in the ground: w (%) = x 100 (2.4)Where : w = Water content (%); Ws = Weight of solid granules (gr); Wow = Weight of water (gr).

Pore Number
The pore number or void ratio (e) is the ratio between the volume of voids () with granular volume () in the soil.The pore number is expressed in decimal form.e = x 100 (2.5)Where : e = Pore number; Vv = Cavity volume (cm 3 ); vs = Granule volume (cm 3 ).

Porosity
Porosity or porosity (n) is defined as the percentage ratio between the volume of the cavity () with a total volume () in the soil.Porosity is usually multiplied by 100%, so porosity can be expressed in percent form: n = x 100 (2.6)Where : n = Porosity (%); Vv = Cavity volume (cm 3 ); V = Total volume (cm 3 ).The relationship between void number and porosity is:

Degree of Saturation
The degree of saturation (S) is the ratio between the volume of water () with the total volume of soil pore cavities ().S = 0 if the soil is dry and vice versa if the soil is saturated, then= 100% or Degree of saturation of a soil () can be expressed in equation 2.9 and as shown in Table 1.S (%) = x 100   (2.9)Where : S = Degree of saturation (%); Vw = Volume of water (cm 3 ); Vv = Total volume of soil pore cavities (cm 3 ).
Table 1 Degree of Saturation and Soil Condition

Volume Weight of Solid Granules
The volume weight of solid granules (γs) is the ratio between the weight of soil granules () with the volume of solid soil grains ().The volume weight of solid granules (γs) can be expressed in the equation: (2.12) Where: γs = Solid volume weight (gr/cm 3 ); Weight of soil granules (gr); = Total solid volume (cm 3 ).

Density/Specific Weight
Specific gravity or specific gravity (Gs) is defined as the ratio between the volume weight of soil grains (γs) and the volume weight of water (γw) with the same contents at a certain temperature.Specific weight () can be expressed in equation 2.13 and the limits of the specific weight of soil are as shown in Table 2.

Atterberg boundaries
Atterberg was a Swedish soil researcher who discovered the Atterberg boundaries in 1911.Atterberg proposed there were five states of soil consistency.The soil consistency limits are based on water content, namely liquid limit, plastic limit, shrinkage limit, sticky limit and cohesion limit.But in general the sticky limit and cohesion limit are not used (Bowles, 1991).The consistency limits are as shown in Figure 1.The shrinkage limit experiment was carried out with a porcelain cup with a diameter of 44.4 mm and a height of 12.7 mm.The inside of the cup is coated with lubricant and filled with perfectly saturated soil which is then dried in an oven.The volume is determined by dipping it in mercury.The shrinkage limit can be expressed in the equation: (2.14) Where: m1 = Weight of wet soil in the test cup (gr); m2 = Heavy v1 = Volume of wet soil in the cup (cm 3 ); v2 = Volume of oven dry soil (cm 3 ); γw = Specific gravity of water (gr/cm 3 ).

a. Plasticity Index
The plasticity index is the difference between the liquid limit and the plastic limit.The plasticity index is the water content interval where the soil is still plastic.The plasticity index can indicate the plasticity properties of the soil.If the soil has a small plastic area water content interval, then the soil is called thin soil, whereas if a soil has a large plastic area water content interval it is called fat soil.Equation 2.15 can be used to calculate the plasticity index value of a soil.IP = LL -PL (2.15) Where: IP = Plasticity index (%); LL = Liquid limit (%); PL = Plastic limit (%).
The interval between water levels when the soil is still plastic is called the plasticity index (PI).The PI value is the difference between the liquid limit value (LL) and the plastic limit value (PL).Atterberg (1911) provides limits on plasticity index values for plasticity properties, types of soil, and soil cohesion properties as shown in Table 3 shows the limits on plasticity index values for soil types.

Soil Mechanical Properties Soil Compaction (Compaction)
Soil compaction is a process where the air in the soil pores is removed by mechanical means (crushed/pounded) so that the soil particles become denser.In other words, compaction is the densification of saturated soil by decreasing the volume of voids filled with air, while the volume of solids and water content remain essentially the same.This is the clearest and simplest way to improve the stability and bearing strength of the soil.
The purpose of soil compaction according to Hardiyatmo (1992), includes: 1. Increases soil shear strength; 2. Reduces compressibility (compressibility); 3. Reduces permeability; 4. Reduces volume changes as a result of changes in water content and others.
Clay soil has low permeability and this soil cannot be compacted well in wet conditions like silt soil.Clay soil that is compacted in the correct way will provide high shear strength.The stability of the swelling-shrinking properties depends on the type of mineral content.
The relationship between dry volume weight (γd) with wet volume weight (γb) and water content (%) is expressed in the equation: (2.16) In the compaction test in the laboratory, the compaction tool was a cylindrical mold with a volume of 9.34 x 10−4 m3, and a pounder weighing 2.5 kg with a drop height of 30.5 cm.In the compaction test, the soil is compacted in 3 layers (standard proctor) and 5 layers (modified proctor) with 25 blows.
The difference between standard proctor compaction testing and modified proctor compaction testing is as shown in Table 4. Soil shear strength is the resistance force exerted by soil grains against push or pull.On a basis like this, if the soil experiences a load it will be supported by: • Soil cohesion depends on the type of soil and its compaction, but does not depend on the vertical stress acting in shear.
• The friction between soil grains is directly proportional to the vertical stress in the shear plane.Therefore, the shear strength of the soil can be measured using the formula: τ = + (σ − u) tan∅ (2.17

RESULTS AND DISCUSSION
OnThis chapter presents the processing of laboratory data from variations in the stabilization of clay soil with lime.The data processing presented is in accordance with the methodology contained in Chapter III and uses the theories and formulas presented in Chapter II.The planned results obtained from this research are soil classification, soil shear strength values, soil cohesion, and friction angle, as well as the influence of soil shear strength and its parameters with the lime mixture.

Lime PSA Test Results
The tests carried out on lime include mineralogical content testing and PSA (Particle Size Analyzer) testing.Based on these results, it can be concluded that lime generally contains silica, alumina and other minerals which can act as soil stabilization materials.The results of the PSA test from lime obtained data as shown in Figure 2.These results show that lime passes 84.82% at a diameter of 0.075 mm.The graph from the test results obtained a good gradation with the smallest lime particles reaching a diameter of 0.107 µm at 0.07%.Therefore, lime can function as a filler for soil.

Scanning Electron Microscope(SEM)
The morphology of solid compounds and the elemental composition contained in a compound can be determined using a scanning electron microscope (SEM).SEM is a type of electron microscope that is able to image the surface of a sample through a scanning process using high energy beams of electrons in a raster scan pattern.Electrons interact with the atoms that make up the sample to produce signals that provide information about surface topography, composition and other properties such as electrical conductivity This can be seen in Figure 3 below.

CONCLUSION AND ADVICE
Based on the analysis results, it can be concluded that Gayo Lues limestone has a good ability to increase the stabilization shear strength of clay soils.In comparison with other soil sources such as clay, sandy soil and gravel soil, Gayo Lues limestone provides better results.Therefore, Gayo Lues limestone can be the right choice in the stabilization process.In this research, a comparison of the stabilized shear strength of clay soil with Gayo Lues limestone has been carried out with several other soil sources for landslide analysis.The analysis results show that Gayo Lues limestone has a good ability to increase the strength and stability of clay soil.It is hoped that this research will provide useful information in selecting the right soil stabilization material.
weight (γ) is the weight of soil per unit volume, soil experts sometimes refer to unit weight as wet unit weight.γ =   (2.10) Where: γ = Wet volume weight (gr/cm 3 ); Weight of soil granules (gr);= Total volume of soil (cm 3 ).Dry Volume WeightDry volume weight (γd) is the ratio between the weight of soil granules () with the total volume of soil ().Dry volume weight (γd) can be expressed in the equation: volume weight (gr/cm 3 );

Figure 2
Figure 2 Lime PSA Test Results

Figure 3
Figure 3 Comparison of the results of light microscopy with SEM Source: Munirwansyah -Amalia Shear Strength Analysis Results The analysis results show that the stabilization shear strength of clay soil with Gayo Lues limestone is higher compared to other soil sources.Comparison of the stabilization shear strength of clay soil with Gayo Lues limestone with other soil sources shows that Gayo Lues limestone provides better results.Clay soil, sandy soil and gravel soil have lower stabilization shear strength compared to Gayo Lues limestone.This can be seen in Figure 4 below.

Figure 4
Figure 4 Graph of the Relationship between Shear Stress Ratio and Shear Stress to Horizontal The preparatory work carried out by researchers in this study is: a. Look for literature related to clay soils stabilized with lime.b.Determine and organize the tools used during research, starting from early stage research to final stage research.The equipment used in this research is tools for Water Content Testing, Specific Weight Testing, Consistency Limit Testing, Compaction Testing and other equipment in the Soil Mechanics Laboratory, Civil Engineering Department, Lhokseumawe State Polytechnic.c. Preparing soil samples used in this research taken from the areaBlangjerango District, Gayo Lues Regency.d.The lime used isLime is taken from limestone mountains located in the Tripe Jaya District, Gayo Lues Regency.

Table 2 .
Specific weight of soil