Hydrometer Research Articles

Analysis of the Seasonal Change on the Sediment Transport in the Primary Channel of Saddang Irrigation Area

Irrigation channels are a vital component of an agricultural system, functioning to distribute water to agricultural land and support food security. The Saddang irrigation area, one of the main irrigation regions in Indonesia, plays a crucial role in enhancing agricultural productivity. However, the sediment accumulation in irrigation channels can significantly impact water distribution efficiency and environmental quality. The current research aims to analyze the influence of flow parameters during the rainy and dry seasons, examine the relationship between seasonal changes and sediment transport, and assess the impact of sediment discharge in the primary channel of the Saddang irrigation area. The tests conducted included sieve analysis, specific gravity, sediment concentration, and hydrometer analysis. Based on the research results, the average sediment discharge during the rainy season in the primary channel of the Saddang irrigation area is 2,702 tons/day, while during the dry season, the average sediment discharge is 100 tons/day. The ratio of the average sediment discharge between the rainy and dry seasons is 27:1. Additionally, linear equations were obtained to predict sediment discharge in the primary channel of the Saddang irrigation area. For the rainy season, the linear equation used is y = 857.67x - 1618.3, while for the dry season, it is y = 38.811x - 79.937. These equations have a validation rate of 98% between the linear equation and the actual calculation results, indicating high accuracy in modeling sediment discharge in the channel.

The Use of Dynamic Cone Penetrometer to Predict California Bearing Ratio Value of Subgrade Soils

California Bearing Ratio (CBR) is an indirect method mostly used to investigate the strength of subgrade material for highway design. The CBR of subgrade materials can be determined from costly and time-taking laboratory or in situ CBR tests. These limitations suggest the need for an easy and low-cost in situ direct method to estimate the CBR of subgrade materials. Dynamic cone penetration (DCP) is easy, quick, and economical in situ test in geotechnical uses. However, the use of DCP test to evaluate the CBR of subgrade material is condition specific i.e., local conditions should be considered before adopting existing correlations in engineering design. The objective of this study is therefore to develop a correlation that can predict the CBR of subgrade material from the dynamic cone penetration index (DCPI). Several laboratory and field tests including Plasticity index (PI), Liquid limit (LL) and Plastic limit (PL), in situ density, and classification (sieve analysis and hydrometer analysis), CBR (unsoaked), in situ moisture content, and DCP were conducted. The suitability of the existing model to predict CBR from DCPI was checked. The prediction model was then developed using Statistical Package for the Social Sciences (SPSS) software. The result of the SPSS analysis is log (CBR) = 2.954 – 1.496log (DCPI) with R2 = 0.943. The result shows that a good correlation exist between the dynamic cone penetration indexes (DCPI) and unsoaked CBR values.

An Analysis Management by Mike 21 Modelling at Rolak 70 Retention Pool in Jombang Regency, East Java Province, Indonesia

Some areas in Indonesia have high level of sedimentation problems that able to cause flooding, and one apparent solution is to build a retention pool. Sedimentation is deposition of material into the reservoir or dam due to environmental damage or erosion occurs in the river basin area. Sedimentation becomes the main factor in constructing the Rolak 70 Retention Pool, as an important component in controlling floods on the Konto River when the water discharge exceeds the maximum limit. From geography perspective, the modelling location is in waters located between 112° 11′ 22.85″ South Latitude and 7° 38′ 42.23″ East Longitude. The model area has northern boundary at the tip of Rolak 70 pool, while western boundary at the outlet of Rolak 70 pool. The lowest water depth value is located in upstream area of Konto River at coordinates of 112°11’27.81″ South Latitude and 7°38’49.27″ East longitude. Weight of soil sample taken from the research site was ± 1000 grams at each point, and the result of sediment sample test performed at the Soil Mechanics Laboratory of Civil Engineering Department, Sultan Agung University, Semarang showed that the research area is dominated by sand, followed by mud and gravel. There were several tests conducted include grain size analysis, hydrometer analysis, and specific gravity analysis to determine the D50 of the sediment. In the study area, several sampling points were taken, started from upstream area of the river in front of Rolak 70 building to the Rolak 70 Retention Pool. For this purpose, a MIKE 21 software modelling was used to determine distribution and lines of sedimentation in the study area. As visible from changes found in bed level morphology that occurred in Rolak 70 Retention Pool by cross section extraction, it can be seen that the largest change occurred in analysis for line 1 and the smallest bed level changes occurred in the analysis for line 6. Then, the result revealed that sedimentation tends to occur at large locations in upstream area of Rolak 70 Retention Pool, while the smallest sedimentation potential will happen at the downstream area of Rolak 70 Retention Pool. These results can be caused by changes of speed from the river flow which tends to decrease towards the end of Rolak 70 Retention Pool. So, the river flow has no more energy to carry heavy amount of sediments originating from the upstream area of the Konto River. By the existence of this retention pool, the need for rice field irrigation will not be disturbed by sediment deposits. In addition, the Rolak 70 Retention Pool can be used as temporary storage for material from Mount Kelud eruption where these materials can be utilized as building material or other useful purposes.

Effect of Soil Texture on Agricultural Machine Performance in Sylhet, Bangladesh.

Soil texture is one of the primary soil physical properties that largely affects agricultural machine performance. Before implementing an agricultural machine at the farm level, it is important to test the machine to gain an understanding of its technical functionality and economic viability to get the best output from it. The research was carried out to assess how soil texture influences the performance of machinery, aiming to determine the effectiveness of agricultural equipment on a particular type of land. Soil samples were collected from nine different fields, and their textures were determined using hydrometer analysis. To correlate soil textural classes with machine performance, machinery data—effective field capacity, forward speed, and field efficiency—were calculated by operating a combine harvester on the study areas during the harvesting season of Boro rice. Two types of soil were identified: loamy sand and sandy loam. The findings of the study showed that machine efficiency has a positive correlation with sand proportion and a negative correlation with clay and silt fractions. It was observed that soil with loamy sand-type textural classes demonstrated better field efficiency, higher effective field capacity, and higher forward speed compared to sandy loam soil. Small and irregularly shaped fields also caused variation in performance. The study identified significant variation in speed between these two types of soils but no significant effect on effective field capacity or field efficiency at the 5% level of significance. The outcomes of this research will help farmers make informed decisions when selecting appropriate equipment for their agricultural operations.

Design and Implementation of Large-Scale Hard Rock AMD Dewatering and REE Production

To develop a domestic Rare Earth Elements (REE) supply chain the Hydraulic Preconcentrate (HPC) produced at the Horseshoe bend treatment plant (HSB) was evaluated as a potential source for feedstock. After the clarifiers were flipped to the desired pH set points, a total of 24 Geobags were repeatedly filled and allowed to passively dewater. The Geobags evaluated were comprised of a mix of Woven, Non-woven, and Capillary Channel Fiber (CCF). The bags were constructed with either a composite of woven and nonwoven or only woven geotextile. Half of the bags of both types also included “fins” made of CCF to evaluate their impact on dewatering. Column Filtration Tests (CFTs) were performed onsite to provide laboratory value for hydraulic conductivity. Throughout their dewatering, the geobags were sampled to determine their rate of dewatering. Influent samples from HSB were also tested to produce a Specific Gravity (Gs), via pycnometer testing and Grain Size Distribution (GSD), via sieve and hydrometer analysis. The dewatering ability of the geobags was high regardless of bag material with a mean total solids percentage of approximately 40% across all samples after only one month of dewatering. The GSD performed on the HPC is gap graded with most particles having a diameter of approximately 0.5-0.05mm. Hydraulic conductivity values for the filter cakes during Column Filtration Testing ranged from 0.5 to 2.5 meters/day. This data will help to guide development of future large-scale HPC dewatering and the parametric design of an REE oxide production plant at the HSB site.

SOIL ERODIBILITY AND ITS EROSION POTENTIAL IN SADAWARNA DAN AND SURROUNDING AREA, CIBOGO DISTRICT, SUBANG REGENCY, WEST JAVA PROVINCE

The Sadawarna Dam and its surroundings, which are located in Subang Regency, are currently under construction. Change in land use caused by the construction occurred. Land management and soil conservation are needed to prevent uncontrolled erosion because it can caused slopes in critical condition, flood occurred in the downstream areas of river, and silting of dam. One of the information in land management and soil conservation is by identifying the soil erodibility which aims to find out the sensitivity of the soil to erosion in the research area. Soil erodibility affected by grain size distribution, soil structure, soil organic matter, and soil permeability. In this research area, the soil erodibility was calculated based on disturbed sample in the field which was then tested in the laboratory. The laboratory tests include sieve analysis, hydrometer analysis, and %c organic. Soil permeability obtained from previous studies. The research area is dominated by clay-sized soil which are the result of weathered claystone in Subang Formation. Soil erodibility value in the research area ranged from 1,100 – 0,448 t ha h/ha MJ cm with dominance of low soil erodibility classes. The dominance of clay-sized soil causes low soil erodibility value because clay sized soil has cohesive properties so it tends to be difficult to erode.

Integrating Geographic Information Systems and Hydrometric Analysis for Assessing and Mitigating Building Vulnerability to Flash Flood Risks

Climate change represents an overwhelming challenge that demands urgent intervention for effective resolution. Among the devastating consequences of climate change, flash floods stand out as one of the most catastrophic repercussions. This research focuses on two primary objectives. Firstly, it aims to evaluate the existing state of flash flood intensity (FFI) in a specific area of Hamamatsu city, Japan, which frequently experiences flash flood incidents. Secondly, it seeks to develop a mitigation plan to alleviate the adverse impacts of flooding on buildings within the area. To accomplish these objectives, four parameters related to FFI (namely, runoff depth, runoff velocity, runoff duration, and affected portion) were selected and estimated through the implementation of hydrological and hydrodynamic models. Additionally, a hydrological model was employed, utilizing a storm event with a return period of 100 years as input. During this simulated storm event, FFI values were calculated and categorized into four distinct levels. The results revealed that more than one-tenth of the examined buildings encountered the highest scale of FFI (category 4), while categories 3 and 4 combined accounted for nearly three-quarters of all buildings in the study area. Moreover, two mitigation strategies were adopted to prevent flooding within the buildings’ vicinity. Finally, this study provides a valuable framework and guidance for decision-makers and insurance companies, enabling them to assess the flood hazard status of buildings and make informed decisions accordingly.

Enhancing water resistance of earthen buildings by using admixture materials

ABSTRACT This study aims to find solutions to the weak water resistance problems of earthen buildings and reduce the frequency of the periodic maintenance they require by using admixture materials in the production of soil building materials which will be tested for their effectiveness in the enhancement of earthen buildings' water resistance. In the study, the chemical and mineralogical properties of the cohesive (clayey) soil material, which is locally called 'Gavcin' and used on flat soil roofs in the Kemaliye district of Erzincan province, were determined by XRF and XRD methods whereas the grain size distributions of them were analyzed through granulometric and hydrometric analysis. For the analysis, six different admixture materials were mixed with the original material and the liquid limit (WL), plastic limit (WP), plasticity index (IP), and soil's natural unit volume weight of the original material versus the admixture-added materials were determined. Mortars were produced with original and additive materials in order to determine their physical properties. Unit volume weights, specific gravity, density, compaction-porosity, weight water absorption potential, hardened volumetric water absorption and capillary water absorption (capillarity) capacities of the produced mortars were determined on the 28th and 365th days, respectively. In terms of consistency limits, the most satisfactory experimental results were obtained from G3 and G7 samples (29.3% and 31.3% of Liquid limits and 27.9% and 27.4% of plastic limits). In addition, these two specimens were observed to be most resistant specimens to capillary suction at the end of 28 and 365 days.

Smart soil image classification system using lightweight convolutional neural network

In the agriculture sector, soil classification plays a significant task, as it helps in soil tillage, crop selection, moisture level estimation, and automation. Conventionally, soil classification is carried out with the help of physical, chemical, and biological characteristics of the geo-referenced and mapped soil. Soil classification by conventional and laboratory methods is time-consuming, high-cost, and requires proficiency. This study presents a quick and cost-effective prediction of soil type by using soil images. A soil image dataset has been created to classify the soil type using images. To create the soil image dataset, 392 soil samples are collected from different agricultural fields in Andhra Pradesh, India. The collected samples are dried and the soil type is identified using a sieve and hydrometer analysis in the laboratory. An imaging setup has been made to capture the images of the dried soil samples using a smartphone camera. The captured images are pre-processed using: RGB extraction, and V extraction from HSV bins, and adaptive histogram are applied to highlight the texture features of the soil images. A novel lightweight convolutional neural network called Light-SoilNet is proposed to classify five soil sample images: sand, clay, loam, loamy sand, and sandy loam. The proposed network is designed to take care of the imbalanced soil image dataset. The proposed network is tested and compared with state-of-the-art lightweight and pre-trained deep learning networks. The proposed Light-SoilNet network architecture has produced an overall accuracy of 97.2% in classifying the soils. The comparison of the results shows the performance of the proposed model using the image and deep learning techniques in classifying the soil types.

CORRELATIONS OF PHYSICAL-MECHANICAL PROPERTIES OF THE BOBONARO CLAY IN TIMOR, AND ITS IMPLICATIONS IN GEOTECHNICAL WORK

Many geotechnical problems like slope failures and other infrastructure damage are common in civil and mining projects on the Bobonaro Clay Complex in Timor. Obtaining relevant geotechnical data for a complete engineering analysis is often time-consuming and expensive. Therefore, a study on the relationship between the parameters can be a powerful tool in these situations. Here we used multiple linear regression analysis to determine the correlation between the physical properties (clay content and plasticity index) and mechanical properties (angle of internal friction and cohesion) of the Bobonaro Clay. The data are 53 clay samples from Kupang, East Nusa Tenggara Province. These samples were from geotechnical drilling and Atterberg tests, grain size–hydrometer analysis, and unconsolidated–undrained Triaksial tests. Of all the correlation attempts, we found that only the clay content – plasticity index, and clay content – angle of internal friction exhibited a moderate correlation with a positive trend. The results of the multiple linear regression correlation also failed to express a good model; therefore, it was replaced by simple linear regression analysis. The various factors that need to be considered in a geotechnical correlation study, along with the significance and uniqueness of the Bobonaro clay, are also addressed in this article.

Potential Uses of Local Clay Materials for the Production of Porcelain Electrical Insulators, Ethiopia

AbstractClays are extremely variable materials with different mineral compositions, and they are the main ingredients in ceramics applications. Their properties play specific roles in influencing the technological properties and performance of ceramics products. Evaluating the various properties can help to determine the best way to utilize clay materials, such as the locally available Bombawuha (BC) and Denkaka (DC) clays mined from Ethiopia's Bombawuha and Denkaka areas, respectively. The objective of this study was to examine these materials for the purpose of using them to produce quality electrical porcelain insulators. The clay samples were characterized for their chemical composition, mineralogy, thermal properties, plasticity, and particle-size distribution, using atomic absorption spectrometry (AAS), X-ray diffractometry (XRD), differential thermal analysis coupled with thermogravimetric analysis (DTA-TGA), the Atterberg plasticity test, and sieve hydrometer analysis. Based on the characteristics, suitable clay materials were selected and mixed with feldspar and quartz to formulate various porcelain body compositions which were fired at three different temperatures (1200, 1250, and 1300°C) and dwell times (1.5, 2.0, and 2.5 h). The mineralogy, water adsorption, apparent porosity, bulk density, dielectric strength, flexural strength, and microstructure of the fired bodies were measured. The results revealed that, compared to DC, BC contains kaolinite as the major mineral with appreciable amounts of silica (46.72 wt.%), alumina (35.32 wt.%), and fluxing oxides but smaller amounts of CaO. BC contains greater clay fractions (20.58 wt.%); and has a middle-range plasticity index (PI = 11.2 wt.%), thus making BC suitable for producing porcelain insulators. A test-body composition of 40 wt.% BC, 40 wt.% feldspar, and 20 wt.% quartz, fired at 1250°C for 2 h, exhibited water adsorption of 0.17 wt.%, apparent porosity of 0.42 wt.%, bulk density of 2.45 g/cm3, a dielectric strength of 8.22 kV/mm, and flexural strength of 43.63 MPa and, thus, satisfied the required properties for quality porcelain insulators.

The Particle Size Distribution of Laterite Soil at Ekosodin, Benin City, Nigeria

The laterite soil particle-size distribution provides a preliminary knowledge of the rate of failure and the strength of soil to resist load pressure and subsequent susceptibility to gully erosion. This study was carried out to determine the particle size distribution of laterite soil at Ekosodin, Benin City, Nigeria using appropriate standard methods. This was achieved by collecting a total of twenty soil samples from the gully zone of Ekosodin and carrying out sieve and hydrometer analyses on the recovered soil. The average percentage weight of fines smaller than the following grain diameters: 1.18mm, 0.425mm, 0.075mm, 0.040mm, 0.010mm, 0.003mm, and 0.001mm, were approximately 96%, 74%, 45%, 35%, 28%, 21%, and 15% respectively. The coefficient of uniformity and coefficient of curvature classified the laterite soil as a well graded soil consisting of a representative of all grain sizes in a good complementary proportion. However, the significant quantity of fine in the soil composition made it susceptible to gully erosion in the presence of intense water movement.

Investigation into the Effect of Rice Husk Ash in Partial Replacement of Cement in Concrete

The purpose of this study was to investigate the properties of Rice Husk Ash (RHA) as a partial cement replacement material in concrete production based on analysis of its contribution to strength in comparison with Ordinary Portland Cement (OPC). The analysis was focused on: the chemical properties of RHA, workability, density, compressive strength, and tensile strength of concrete. The RHA was obtained from Mwea, Kirinyaga County, Kenya and burned in a kiln to produce white ash which was tested. Chemical analysis to determine the pozzolanic properties of RHA was done using the Gravimetric method, Flame Photometry and Atomic Absorption Spectroscopy while particle size distribution of RHA was carried out using sieve analysis and hydrometer analysis. Concrete mixes with different ratios of OPC to RHA binder were cast into cuboid and cylindrical samples. The binder was made by replacing OPC with RHA at intervals of 10% by mass to a maximum of 50% replacement. A binder, sand, and ballast ratio of 1:1.5:3 were maintained with a constant water-cement ratio of 0.6. The cast samples were subjected to water curing on the third day at room temperature. Workability tests were performed on fresh concrete while compressive strength tests and tensile strength tests were performed on hardened concrete in all the mixes. The results were compared with OPC concrete. Results indicated that Kenyan RHA has high silica, alumina, and iron oxide content of about 92%. The workability slightly improves with 10% partial replacement of OPC with RHA but decreases with further addition of RHA. It was also deduced that the optimal binder mix was 10% partial replacement of OPC with RHA however the compressive strength was lower than the OPC concrete by 2.3%. The tensile strength of concrete increased with the addition of RHA up to an optimum of 10%.

Correlation between soil erodibility and light penetrometer blows: A case study in Sungai Langat, Malaysia

The soil erodibility (K) factor is one of the key parameters used for predicting and estimating soil erosion in models such as Universal Soil Loss Equation (USLE) and Modified Universal Soil Loss Equation (RUSLE). It is the inherent resistance of soil to survive erosion and reflects the susceptibility of soil to the erosion process. Long-term studies for direct measurement of K factor are time-consuming and expensive, so efforts were made by the researchers to develop simple indices to relate soil properties with K factor for instant and economical estimation of erodibility. Mackintosh Probe is a portable and lightweight dynamic penetrometer that provides a relatively fast, economical, and easy assessment of subsoil. In this study, soil samples were collected from the Sungai Langat site, and a series of laboratory tests, including sieve analysis, hydrometer analysis, and organic matter content, were performed. K factor was determined by employing Wischmeier and Tew equations. The mean values of the K factor for the Sungai Langat site were found to be 0.005 and 0.0045 for Tew and Wischmeier equations, respectively. Multiple regression analysis was performed to analyze the relations between Mackintosh Probe and K factor, which the coefficient of multiple correlation values of 0.345 and 0.352 for the Tew and Wischmeier equation, respectively. Although the analysis represented a weak relation between Mackintosh Probe values and K factor, however, it provides a basis for the research perspective to simplify the estimation of soil erodibility with a minimalistic experimental setup.

Performance Testing Of Sand And Lime As Subgrade Stabilizing Materials For Roads

Soil stabilization is a method used to increase the carrying capacity of a layer of soil, by giving special treatment to that layer of soil. Soil is one of the factors that can affect the structure of road construction. The CBR value is one of the parameters to determine soil carrying capacity, if the CBR value is high then the soil carrying capacity is good, whereas if the CBR value is low then the soil needs to be stabilized. The purpose of this study was to determine the characteristics and classification of soil, determine the results of the grain gradation test, sieve analysis and hydrometer analysis, consistency limits (Atterberg limits) before and after stabilization, compaction results (Proctor) before and after stabilization, determine the CBR value of the soil before and after stabilization. This research included water content test, wet soil unit weight test, specific gravity test, sieving analysis, hydrometer analysis, Atterberg limit test, compaction test (Modification), and immersion CBR test and CBR without immersion. In this test, variations in the addition of 20% sand and lime content were 5%, 10% and 15% of the dry weight of the soil. From the test results, the original soil samples showed soil classification A-7-6 according to AASHTO with maximum dry density (MDD) values of 1.70 gr/cm3 1 day curing, 1.64 gr/cm3 7 days curing and 1.77 gr/cm3 for 14 days curing, there was an increase in the value of the maximum dry density (MDD) in the original soil stabilized with 20% sand and 5% lime, a value of 1.78 gr/cm3 was obtained for 1 day curing, 1.86 gr/cm3 cm3 7 days curing and 1.82 gr/cm3 14 days curing. From the test results, the original soil samples showed soil classification A-7-6 according to AASHTO with CBR values of soaked 3.15% 1 day curing, 3.68% 7 days curing and 4.21% 14 days curing, there was an increase Soaked CBR values on native soil stabilized with 20% sand and 5% lime obtained CBR values of 37.19% at 1 day curing, 42.10% 7 days curing and 30.29% 14 days curing.

INFLUENCE OF SALINITY LEVELS ANALYSIS ON SETTLING VELOCITY OF FINE SEDIMENT GRAINS IN CILIWUNG ESTUARY

Transport of estuarine sediment have a highly complex method, which is the combined effects result of periodically reciprocating flow, ocean waves, and the electrochemical characteristic of sea water [1]. Settling velocity (SV) is such a parameter fundamental for sediment researchers so that its accurate resolution has been regarded as a top priority in correcting modelling numerical and conceptual understanding of fine sediment dynamics [2] [3]. The goal of this study is to analyze the effect of salinity levels on the settling velocity of fine sediment grains in the Ciliwung estuary, Jakarta. The method used is direct measurement using the hydrometer analysis method. The result of experiment shows salinity levels affect the settling velocity of fine sediment grains in the Ciliwung estuary. The higher salinity, more faster the settling velocity of fine sediment grains. The average settling velocity at distilled water salinity 0 ppt is 1.083 mm/minute, sea water with salinity 0.3 ppt is 1.537 mm/minute, and sea water with salinity of 0.6 ppt of 1.561 mm/minute.

Impact of the Salt Concentration and Biophysical Cohesion on the Settling Behavior of Bentonites

The flocculation behavior of clay minerals in aquatic environments is an important process in estuarine and riverine dynamics, where strong gradients in salinity can locally occur. Various contradicting observations have been reported in the literature on the impact of salt concentration on the settling process of cohesive sediments. To address this issue in a systematic manner, we investigate the settling behavior of clay minerals as a function of the salt concentration of the ambient water. Specifically, we focus on montmorillonite as a prototype clay mineral with a high cation exchange capacity (CEC). To this end, we study suspensions of Wyoming bentonite (Volclay SPV) as a very important constituent for many constructional and industrial purposes. We perform an experimental campaign to study the settling behavior of moderately turbid montmorillonite concentrations in monovalent salt solutions with different salinities (sodium chloride) to represent different environments ranging from deionized to ocean water, respectively. The subsequent settling process was monitored by taking pictures by a camera in regular time intervals over a total observation time up to 48 h. In addition, a modified hydrometer analysis is conducted to determine the grain size distribution (in terms of an equivalent diameter) of the flocculated clay suspension in salt water. Despite the rather high cation exchange capacity of the investigated clay (CEC=88.1), our results show that the settling speed drastically increases within a range of 0.6–1.0 PSU and stays approximately constant for higher salinities. This critical salt concentration is defined here as the critical coagulation concentration (CCC) and lies well below the salinity of natural open water bodies. The hydrometer analysis revealed that 60% of the agglomerates exceed the equivalent grain size of 20 μm. Finally, the findings of this study are supplemented with experiments studying the effect of Extracellular Polymeric Substances (EPS) on the flocculation behavior of bentonite in salt water. Our results demonstrate that salinity is the original trigger for flocculation, whereas EPS allows for even larger floc size but it does not play a significant role for the settling processes of bentonite in estuarine environments.

Effect of KOH Treated Coir Pith on Compressive Strength of Clayey Silt

Kuttanad soils are low strength soft clay or silt deposits found in the Kuttanad areas of the Alappuzha district, Kerala. Due to its low load-bearing and high shrinkage characteristics, the structures and pavements constructed over were unstable. Treatment with appropriate chemical additives is one of the accustomed and economic techniques in soil stabilization practice for improving the characteristics of weak soil. Traditional stabilizing agents like cement, lime, etc. are becoming less environmentally friendly and costly. Coir pith (treated and untreated) is proposed in this study. Coir pith was treated using potassium hydroxide. Initial tests like natural water content, specific gravity, Atterberg’s limit test, hydrometer analysis, compaction test, unconfined compressive strength tests were conducted to find the properties of natural soil. Proctor compaction tests, unconfined compression tests are to be performed to investigate the effectiveness of the coir pith to control the volume change and increase the soil strength. Maximum dry density increases with treated coir pith whereas OMC decreases. UCS test results shows an increase in strength which confirm that treated and untreated coir pith are able to effectively stabilize the natural expansive soil.

Utilization of NDMI Method in Landsat 8 Satellite Imagery for Analysis of Multi-Hazard Susceptibility

Liquefaction and landslide can occur during earthquakes caused by changes in soil saturation levels so that the soil loses strength due to loss of tension between grains. One of the determinations of soil moisture data using satellite imagery analysis is Landsat. Landsat has provided moderate, global, synoptic spatial resolution and repeated earth's soil surface coverage. This paper discusses the multi-hazard susceptibility using Landsat-8 satellite imagery with a combination of NDMI (Normalized Difference Moisture Index) ratio bands in Sunurraya Village and Simpang Saga Village, South OKU Regency, South Sumatra. The combination of NDMI bands determines the spread of soil saturation levels and differences in moisture in vegetation conditions. Other supporting data are soil's physical properties, including water content, density, hydrometer analysis, and Atterberg limits analysis. Overlay of NDMI data analysis and soil test analysis shows the level of liquidation insecurity in the research area on a regional and local scale

Correlation between undrained shear strength and liquidity index of soils in Malaysia

Accuracy of soil undrained shear strength measurement is often governed by the quality of undisturbed soil sampling. Numerous previous attempts have been made to establish correlations between the undrained shear strength and various soil physical parameters. This paper aims to determine a correlation between the undrained shear strength (cu) and liquidity index (IL) based on 34 soil samples collected from selected sites in Peninsular Malaysia. Sieving, hydrometer analysis and Atterberg limit tests were performed to determine physical properties of the soils. The undrained shear strengths were determined using the Unconsolidated Undrained (UU) triaxial test. An attempt was made to correlate the undrained shear strength with liquidity index of all the soil specimens. However, the correlation was found to be considerably weak (r2 = 0.47). The correlation was improved significantly (r2 = 0.82) by limiting the data to soils with fines content of more than 65% only. The proposed equation was in the form cu = a exp(-bIL) where the values of constants a and b were determined empirically as 72.9 and 1.95, respectively.