Perencanaan Perkuatan Lereng Menggunakan Geoframe di Jalan Raya Dampit-Lumajang

A Landslide is the movement of soil mass or rock constituents down the slope due to disturbance of soil stability. One of the factors that affect soil stability is the rainy season as happened in Sumberwuluh Village, Candipuro District, Lumajang Regency. The alternative used to stabilize the slope is by changing the slope geometry, then adding geoframe reinforcement. This study aims to determine the value of the factor of safety (SF) of unreinforced slopes, after changing the slope geometry, and after being given geoframe reinforcement. The method used in analyzing slope stability is the Ordinary/Fellenius method. The results of the calculation of slope stability without reinforcement using the Rocscience Slide software obtained a SF of 0.719, while the manual calculation obtained a SF of 0.7191. The two values ​​of the safety factor are less than 1.25, which means that landslides often occur. The results of the calculation of slope stability after changing the geometry of the slopes obtained a SF of 0.828 where the value is less than 1.25 which means that landslides often occur. The slopes that have been changed geometry are added with geoframe reinforcement. The results of the calculation of slope stability using geoframe reinforcement obtained a SF of 1.315 where the value is more than 1.25 which means that landslides are rare or slope in a safe condition.

Development of Mechanical Soil Stability In An Initial Homogeneous Loam And Sand Under In-Situ Field Conditions

PurposeSoil structure evolving from physical and biological processes is closely related to soil mechanical characteristics and texture. A soil plot experiment in Bad Lauchstädt, Germany, allowed us to study the influence of substrate and genotype on the initial development of mechanical traits, differences between depths, and changes over the course of two years. MethodsPlots were homogeneously filled with a loam and a sand and planted with two maize (Zea mays L.) genotypes (wild type (WT) and rth3 mutant) with contrasting root hair attributes. Undisturbed soil cores were taken in 2019 and 2020 at 14 and 34 cm depth. Confined uniaxial compression tests were performed to determine pre-compression stress (σpc), compressibility (Cc, Cs) and elasticity index (EI). Mechanical energy was calculated based on penetration resistance tests with a penetrometer needle resembling root geometries. Resultsσpc, Cc and Cs were significantly higher in loam as compared to sand, whereas the factor genotype proved to be negligible. Over time, σpc increased and Cc decreased in loam from 2019 to 2020 and Cs declined in both substrates. Higher mechanical energies were observed in loam and partially in WT. Required energy was higher at 14 cm than at 34 cm depth and decreased from 2019 to 2020 in sand. Airdry sand samples required four times as much energy than those at -50 kPa.ConclusionFor the development of the mechanical traits examined texture proved to be the dominating factor and changes in soil stability could be observed within a short period of time.

Experimental Study on Electrical Resistivity Characteristics of Saturated Sand Mixes with Bentonite Slurry

Bentonite slurry is widely used in underground and geotechnical engineering because of its strong ability of wall protection. Slurry penetration, which is of great significance for the soil stability, is difficult to observe directly during the soil and slurry interaction. Slurry penetration would change the electrical resistivity of soil, which provides an indirect method to monitor the degree of slurry penetration. This paper aimed to investigate the electrical resistivity characteristics of soil-bentonite mixtures. Several test groups with different material components were carried out. The effects of some factors including water environment, CMC (carboxymethyl cellulose) contents, soil particle gradation, and electrode distance on the electrical resistivity of slurry-soil mixtures were studied and the relationship between soil electrical resistivity and slurry concentration was established. The results in this paper can provide references for the application of the electrical method on slurry penetration.

Best management practices for erosion and sedimentation control of The Sermo Watershed

Erosion and sedimentation problems caused by human activities disturbed the primary conditions of the watershed. This situation was also influenced by significant hydrometeorological shifts and high rainfall, which increased soil erosion. These inclement watershed conditions resulted in high sedimentation rates and caused severe problems for the quality and quantity of water in the reservoir. This study aims to solve the Sermo watershed problems by calculating the value of erosion and sedimentation, then providing a solution to deal with these problems in the form of Best Management Practices (BMP). This research used a USLE method to calculate the erosion and sedimentation rate. The calculation results showed that 40.86% of Sermo Reservoir within 809.12 hectares was classified as a high level of erosion. Further recommendations for overcoming this condition were made by referring to BMP for erosion and sediment control, including structures and soil water conservation. Further recommendations to address this condition were made regarding BMP for controlling water, maintaining soil stability, controlling sedimentation, and managing and maintaining optimal watersheds.

Study of the soil stability theory problems by the simplex method

The questions of linear programming methods application to the main problems of stability theory - problems on slope stability, problems on ultimate pressure of soil on enclosures (case of landslide pressure), and problems on bearing capacity of horizontal base of a die are considered. The problems of stability theory are formulated as linear programming tasks. It is shown that the given systems of equations are linear with respect to the unknowns and may be solved by the Simplex method. The results of soil stability problems calculation by Simplex method are compared with the results of calculations according to the most known classical schemes. It is shown that a great scatter of final results is observed in calculating the stability of slopes by classical methods, and in this case, the results obtained by the Simplex method are the most trustworthy ones. The situation with landslide pressure definition is especially complicated in this sense where classical methods give a scatter of landslide pressure values by several times. It is established that with increasing discretization of the computational domain, the results tend to exact solutions of the limit equilibrium theory, obtained, for example, by the method of characteristics. The latter point is illustrated using the example of the problem of a die pushing into a ground massif with a Hill scheme bulge.

The impact of different tillage practices on soil stability and erosion in a red soil hilly region, China

Tillage practices can change moisture content, nutrient retention and soil properties and so affect crop growth and significantly influence soil stability. The objectives of this study were to evaluate the effects of tillage practices (conventional tillage, CT; soil compaction, CM; subsoil tillage, ST; no tillage, NT; and subsoil tillage and soil compaction, SCM) on soil stability in a hilly region of red soil in China. The parameters of soil stability were soil aggregate stability (SAS), wet aggregate stability (WAS), and soil mechanical stability (SMS). These parameters are closely related to soil erodibility (SE). The results indicated that SAS, WAS, SMS and SE varied significantly across the five tillage methods. The aggregate stability indexes (ASI) of CM (2.64) and CT (2.61) were greater than for other methods, which indicates that CM increased the compactness of soil particles and that the soil structure for NT was relatively stable and less disturbed than for other methods. NT and CM significantly increased soil shear strength (SS) and soil compactness (SC) compared to other methods. NT significantly increased soil resistance to erosion compared to other methods, with K factor = 0.26. NT (ASI = 0.43) had the greatest soil stability and resistance to erosion (SSE), followed by SCM (ASI = 0.41), for which ASI can potentially be increased. The results provide reference parameter values for selecting a suitable tillage method to reduce soil erosion and improve soil productivity in red soil sloping farmland.

Changes in the agrochemical and biological properties of the soil when applying various types and ratios of organic and mineral

The article analyzes the main approaches to assessing the stability of agrocenosis soils. It is revealed that the mechanisms of soil stability are embedded in the structure and nature of the connections between the biota and the abiotic parts of the system, as well as the intra-component and inter-component connections between them. It is established that the structure of the soil is the most important aspect of the stability of any agroecosystem, which persists when its conditions change. A basic model of integral stability of sod-podzolic light loamy soil and agricultural technologies for its provision are proposed. Keywords: SOIL, AGROCENOSIS, AGROECOSYSTEM, STABILITY, STABILITY, ELASTICITY, RECOVERABILITY, INERTIA, PLASTICITY

Enhancing the Soil Stability using Shredded Crumbed Rubber and Lime

The research described herein is an investigation into the engineering properties necessary for use of scrap tires in construction replacing, supplementing, and improving common earthen materials of construction. The shredded crumbed rubber and lime is mixed in various proportions on clay and various properties of soil mixtures are found. The addition of shredded crumbed rubber with lime shows improvement in density and packing in clay, hence its beneficial to use for sub base course.

Definition of Construction Parameters of Discrete Restraining Constructions

Purpose. There are many problems in the design of anti-landslide constructions, therefore discrete constructions are an alternative to solid anti-landslides. Despite the advantages of such constructions, difficulties also arise when using them. In this work, it is envisaged to develop methods for determining the zone of influence of discrete restraining constructions on the interaction of a sliding soil mass with them and a method for assessing the conditions of a stable state of the soil, which interacts with discrete restraining constructions, by constructing analytical dependencies necessary to determine the zone size and the soil stability coefficient. Methodology. Theoretical studies of geomechanical processes using analytical and numerical mathematical methods, as well as analysis and generalization of theoretical research results were used to achieve the purpose. Findings. The research results presented in the work allow, during the design of landslide discrete constructions, to determine the area of interaction of the shear with discrete retaining constructions, as well as to take into account the stability coefficient of the soil laid between the elements of the discrete retaining structure. Dependences were obtained for determining the zone size in which the sliding soil mass interacts, with discrete retaining constructions, and the soil stability coefficient in the zone of its interaction with these constructions. Originality. Analytical dependencies allow to calculate the boom of lifting the soil dumping arch between the elements of the discrete anti-landslide restraining construction and the coefficient of soil stability. Practical value. The research results allow, when designing discrete restraining constructions, to determine the area of interaction of the shear with these constructions and the stability coefficient of the soil laid between the elements of the discrete restraining construction.