Pengaruh Biopolimer Pada Stabilitas Lereng Swelling soil

Many studies have begun to develop the concept of cracked soil. The results of research related to cracked soil are able to answer the irregularities that occur, such as the difference in the results of the stability analysis which is considered safe with the conventional bishop method, while the conditions in the field are landslides. Swelling soil is soil that is susceptible to changes in water content. This type of soil is very prone to cracking. To build infrastructure on the swelling soil type, an improvement must be made, one of which is by mixing the swelling soil with biopolymer. The results of this biopolymer mixing are then modeled in the New Slope Stability Analysis Program (NSSAP) 1.0 which refers to the concept of cracked soil. From the analysis, it was found that the slope safety factor before improvement with biopolymer was 0.305 and the safety factor after improvement with biopolymer was 2.006. From the results of this study, it can be seen that the role of biopolymers in stabilizing swelling soil is quite large, which is around 558%.

Characterization of expansive soils for the foundation of an irrigation canal in the Peruvian Andes, Cabana-Mañazo case

Alterations in water content in swelling soils cause volume variation, which implies constructive, socioeconomic and environmental damage. This paper characterizes the swelling soil located in an irrigation canal of the Peruvian Altiplano and its behavior of the properties by addition of lime in 5, 10, 15 and 20% of the total weight. Finding that the sample of the station 6+575 has combined presence of montmorillonite clays in a percentage of 13.52% together with the group of kaolinites in a percentage of 1.31%, consequently, it makes expandable clay of high plasticity. The soils of the station 6+250 have the characteristics of kaolinite clay, which distinguishes it as having low plasticity. In the swelling tests the high expansiveness was found, in the station 6+575, which has decreased with the addition of lime. Considering that concrete canals are generally of small thickness it would be important to consider the slightly dangerous effects on irrigation infrastructure.

Experimental Study of Bearing Capacity Effect in Swelling Soil

The current study aims to investigate the effects of swell pressure on the bearing capacity of swelling soil. A model and some laboratory tests have been created to investigate the swell pressure effect on the bearing capacity variation of soil swelling due to swelling pressure. The influence of varying water content w/c and dry unit weight (γ d ) on the shear strength and swelling pressure was studied. The soil has been taken from Diwan Residential Compound-Mosul. It is classified as highly swelling soil. The swell pressure of soils at their natural water content reached 385 kN / m2 . Experiment results show that the parameters of shear resistance decreased with the w/c increase at the constant value of (γ d ), increased with the (γd ) increase when the w/c was constant. Results show that the swelling pressure decreased with the w/c increase, while it increased with the (γ d ) increase. Also, the results obtained using was model show that the resistance of bearing capacity of pre-saturated selected soil was 196 kN / m 2, while the bearing capacity was 620kN / m 2 when taking into account in the generation of swelling pressure.

Influence of Curing Temperature on Shear Strength and Compressibility of Swelling Soil Stabilized with Hydrated Lime

The exposed cohesive soils to temperature can face considerable physical and mechanical characteristics changes. Therefore, understanding the environmental events influences on the soil geotechnical properties is essential, which is significant in the rainy and cold places such as in Sulaimani city, northern Iraq. This experimental study examines the temperature changes (10o C, and 50o C) impacts on the durability of stabilized cohesive soil using 0%, 5%, 10% and 15% hydrated-lime added as a replacement on the soils dry mass. Consistency, unconfined compression, and compressibility characteristics were evaluated. Under the applied circumstances, a decrease was noticed in the magnitudes of liquid limit and plasticity index, while plastic limit generally increased within hydrated-lime percent increase. The study yielded an appreciable improvement of the cohesive soil’s strength and compressibility properties with time progress, especially after the stabilization process is achieved.

Bearing capacity of a square shallow foundation on swelling soil using a numerical approach

Purpose The estimation of bearing capacity for shallow foundations in swelling soil is an important and complex context. The complexity is due to the unsaturated swelling soil related to the drying and humidification environment. Hence, a serious study is needed to evaluate the effect of swelling potential soil on the foundation bearing capacity. The purpose of this paper is to analyze the bearing capacity of a rough square foundation founded on a homogeneous swelling soil mass, subjected to vertical loads. Design/methodology/approach A proposed numerical model based on the simulation of the swelling pressure in the initial state, followed by an elastoplastic behavior model may be used to calculate the foundation bearing capacity. The analyses were carried out using the finite-difference software (FLAC 3 D) with an elastic perfectly plastic Mohr–Coulomb constitutive model. Moreover, the numerical results obtained are compared with the analytical solutions proposed in the literature. Findings The numerical results were in good agreement with the analytical solutions proposed in the literature. Also, reasonable capacity and performance of the proposed numerical model. Originality/value The proposed numerical model is capable to predict the bearing capacity of the homogeneous swelling soil mass loaded by a shallow foundation. Also, it will be of great use for geotechnical engineers and researchers in the field.

Interface Direct Shear Tests on JEZ-1 Mars Regolith Simulant

The mechanical behaviors of Martian regolith-structure interfaces are of great significance for the design of rover, development of excavation tools, and construction of infrastructure in Mars exploration. This paper presents an experimental investigation on the properties of a Martian regolith simulant (JEZ-1) through one-dimensional oedometer test, direct shear test, and interface direct shear tests between JEZ-1 and steel plates with different roughness. Oedometer result reveals that the compression and swelling indexes of the JEZ-1 are quite low, thus it is a less compressible and lower swelling soil. The cohesion and adhesion of JEZ-1 are lower than 5 kPa. The values of the internal friction angle range from 39.7° to 40.6°, and the interface friction angles are 16.7° to 36.2° for the smooth and rough interface. Furthermore, the direct shear and interface direct shear results indicate that the interface friction angles are lower than the internal friction angles of JEZ-1 and increase close to the internal friction angles with increasing interface roughness.

Modern Displacement Measuring Systems Used in Geotechnical Laboratories: Advantages and Disadvantages

The paper presents the contemporary displacement measurement systems used in geotechnical laboratories during the determination of soil precise mechanical parameters, e.g., the shear modules G: initial and in the range of small and very small strains. In the laboratory, researchers use standard sensors for measuring deformation, pressure, and force as well as modern measuring systems such as linear variable differential transformers (LVDT), proximity transducers (PT), magnetic encoder sensors with fiber Bragg grating (FBG), or methods based on laser or X-ray measurement. None of the measurements are universal and their use depends on the type of soil (cohesive, non-cohesive), its condition (loose or dense, stiff or very soft), and its characteristic properties (e.g., organic soil, swelling soil). This study points out the interesting equipment solutions and presents the guidelines for selecting appropriate methods of deformation measurement.