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Search results for: SOIL SHEAR MODULUS
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Study on some of the strength properties of soft clay stabilized with plastic waste strips
PublicationIt is well known that if plastic wastes are not well managed, it has a negative impact on the environment as well as on human health. In this study, recycling plastic waste in form of strips for stabilizing weak subgrade soil is proposed. For this purpose, a weak clay soil sample was mixed with 0.2%, 0.3%, and 0.4% of plastic strips by weight of soil, and the experimental results were compared to the control soil sample with 0%...
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Possible effects of the 1984 St. Clair River ice jam on bed changes
PublicationThis study examines the possible effect of the record ice jam of 1984 in the St. Clair River on river bed changes and conveyance. Numerical simulations were made to examine the flow and bed shear stresses during the jam formation and release periods. Simulation results indicate that the ice jam in the river did not cause a significant increase in bed shear stress compared to pre- and post-jam open water conditions. The insignificant...
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The influence of temperature on properties of the polymer flexible joint used for strengthening historical masonries
PublicationA new method of repairing damaged structures by filling the cracks with a specially prepared elastomeric polymer mass has been recently proposed. This new and innovative technique, known as the Flexible Joint Method (FJM), is mainly dedicated to masonries and historical objects, where minimum intervention is permitted. The flexible joint bonds the disrupted elements and ensures further safe exploitation of a damaged structure....
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Tensile and flexural moduli for human orbital wall bones – comparative study
PublicationThe main aims of the current research were: (1) to analyze in detail the tensile modulus and ultimate tensile strength (UTS) of orbital wall bones separately for the left and right orbit of the same cadaver and (2) to compare the obtained results with a flexural modulus of the left and right orbit reported earlier by A. C. van Leeuwen et al. [14]. A set of 54 specimens of orbital superior and/or medial walls harvested from 16 human...
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Effectiveness of Random Field Approach in Serviceability Limit State Analysis of Strip Foundation
PublicationThis work conducts a probabilistic inquiry on how the variability of the parameter defining soil deformability affects the settlement of the foundation located on the soil. The analysis addresses the random foundation model to relevantly estimate the probability of allowable deflection exceedance. The constitutive model parameter is based either on a single random variable or a random field. The computations incorporate direct...
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Impact of an unsecured excavation on an underground pipeline
PublicationThe paper presents a numerical analysis of the impact of an unsecured excavation on an underground pipeline in selected soil conditions. The research was inspired by a real-life failure of a water pipeline which was caused by a nearby unsecured excavation (Sikora et al. 2015). The failure was triggered by displacement of soil mass in the vicinity of the pipeline. The study conducted in the framework of Finite Element...
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The long-term properties of mineral-cement-emulsion mixtures
PublicationThis publication presents evaluation of long-term behavior of mineral-cement-emulsion (MCE) mixtures. MCE mixtures are among the major products of cold recycling of old asphalt pavements. They are composed by binding of the old materials reclaimed from the pavement and new mineral aggregate using two different binding agents – cement and bituminous emulsion. While bituminous emulsion dissolutes and binds materials quite fast, it...
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SAWING PROCESS AS A NEW ALTERNATIVE WAY OF DETERMINING SOME WOOD PROPERTIES
PublicationCutting forces (power) could be considered from a point of view of modern fracture mechanics. The developed cutting model, derived from fracture mechanics, includes work of separation (fracture toughness) in addition to plasticity and friction, and also dullness of the cutting edge described by the cutting edge radius. Moreover, forecasting of the shear plane angle for the cutting models, broaden possibilities of energetic effects...
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EXPERIMENTAL STUDY OF SURFACE ROUGHNESS EFFECT ONTHE RHEOLOGICAL BEHAVIOR OF MR FLUID
PublicationPaper presents the results of shear stress measurements of a commercial magnetorheological fluid using a plate-plate type geometry with a modified working surface. The purpose of the study was to determine the effect of changing the roughness of the measuring plate on the obtained shear stress results. Controlled shear rate tests and Magneto Sweep measurements were carried out for three MR fluid layer heights. The tests were...
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Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
PublicationThe performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to...
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FEM modelling of screw displacement pile interaction with subsoil
PublicationPredicting the-settlement characteristics of piles is an important element in the designing of pile foundations. The most reliable method in evaluating pile-soil interaction is the static load test, preferably performed with instrumentation for measuring shaft and pile base resistances. This, however, is a mostly post-implementation test. In the design phase, prediction methods are needed, in which numerical simulations play an...
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Distinctive properties of Scots pine (Pinus sylvestris L.) originating from the Carpathian and Great Poland-Pomeranian of Nature and Forest Land
PublicationIn this paper values of properties of Scots pine, the fracture toughness and of shear yield stress in the shear zone are presented. Samples of Scotch pine (Pinus sylvestris L.) wood of two provenances from Poland were tested. These properties were determined from the values of cutting power obtained experimentally on the saw frame PRW-15M. The values of fracture toughness and shear yield stress based on the Atkins model for cutting...
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Investigations on strength and fracture in RC beams scaled along height or length
PublicationThe objective of the present paper is to identify experimentally and theoretically differing failure mechanisms in reinforced concrete beams subjected to four-point bending for a separate variation of the depth and length at the constant thickness. Experiments were performed on reinforced concrete beams under four-point bending. Different failure mechanisms included steel yielding, diagonal tension or shear- compression depending...
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Interlaboratory Test to Characterize the Cyclic Behavior of Bituminous Interlayers: An Overview of Testing Equipment and Protocols
PublicationThe performance assessment of multi-layered pavements strongly depends on the mechanical behavior of the interface between bituminous layers. So far, comprehensive studies have been carried out mainly using quasi-static laboratory tests focusing on the interlayer shear strength at failure. However, it is generally recognized that cyclic shear testing will lead to the determination of parameters which are more closely linked to...
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Numerical solutions for large deformation problems in geotechnical engineering
PublicationThe problem of large deformations often occurs in geotechnical engineering. Numerical modeling of such issues is usually complex and tricky. The chosen solution has to implicate soil-soil and soil-structure interactions. In this paper, a review of the most popular numerical methods for large deformation problems is presented. The Coupled Eulerian-Lagrangian (CEL) method, the Arbitrary Lagrangian-Eulerian (ALE) method, the Smoothed...
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Modeling of free vibrations and resonant frequencies of simply-supported submerged horizontal plate
PublicationA theoretical approach was applied to study the vibration of simple-supported submerged horizontal plate. The derived analytical solution was used to determine natural frequencies for a horizontal plate vibrating in fluid. The investigations were conducted for a very wide range of material density and elasticity modulus covering all materials used in engineering practice. Analysis shows that plate vibration frequency decreases...
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Excavation induced cast iron pipeline failure – a numerical study
PublicationNumerical study on impact of an unsecured excavation on an underground pipeline. Analysis focused on investigation of pipeline displacement generated by soil movement caused by excavation and heavy traffic. Numerical calculations and soil parameter sensitivity analysis based on Finite Element Method. Some comparisons of results with real-life failure cases.
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Influence of addition of carbon nanotubes on rheological properties of selected liquid lubricants - a computer simulation study
PublicationThis work is motivated by the improvement of anti-friction properties of lubricants by addition of CNTs proved experimentally in literature. In particular, a methodology is developed to compute the shear viscosity of liquid lubricants (Propylene Glycol) based on Molecular Dynamics simulation. Non-Equilibrium molecular dynamics (NEMD) approach is used with a reactive force field ReaxFF implemented in LAMMPS. The simulations are...
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The impact of footing conditions of a vertical-axis floating-roof tank on structural shell deformation
PublicationStructural shells of fuel tanks are often subjected to geometric imperfections which may lead to exceeding the ultimate and serviceability limit states. One of the means triggering shell deformation is non-uniform settlement caused by incoherent soil conditions. Analysis carried out in the work concerns of vertical-axis, floating-roof cylindrical shell which volume is 50.000 m3, founded on a complex multi-layered soil. The sensitivity...
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Przyczółki mostowe z konstrukcją odciążającą z gruntu zbrojonego geosyntetykami
PublicationPrzegląd najważniejszych cech geotekstyliów i wyrobów pokrewnych, zastosowanych do budowy bloków odciążających ze szczególnym uwzględnieniem ich wytrzymałości długo i krótkookresowej oraz reologii. Określenie obciążeń działających na konstrukcję gruntową współpracującą z przyczółkiem; obciążenia normowe i rzeczywiste. Obliczenia konstrukcji z gruntu zbrojonego współpracującej z przyczółkiem
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Non-linear static stability of bi-layer carbon nanosheets resting on an elastic matrix under various types of in-plane shearing loads in thermo-elasticity using nonlocal continuum
PublicationIn this research, the shear and thermal buckling of bi-layer rectangular orthotropic carbon nanosheets embedded on an elastic matrix using the nonlocal elasticity theory and non-linear strains of Von-Karman was studied. The bi-layer carbon sheets were modeled as a double-layered plate, and van der Waals forces between layers were considered. The governing equations and boundary conditions were obtained using the first order shear...
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Equivalent Single Layer Models in Free Vibration Analysis of Laminated Multi-Layered Plates
PublicationThe performance of selected equivalent single-layer (ESL) models is evaluated within several classical benchmark tests for small amplitude free vibration analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation (FOSD) theory with some modifications incorporated including a correction of the transverse shear stiffness and an application of zigzag type functions....
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Use of Brassica plants in the phytoremediation and biofumigation processes
PublicationIn recent decades, serious contamination of soils by heavy metals has been reported. It is therefore a matter of urgency to develop a new and efficient technology for removing contaminants from soil. Another aspect to this problem is that environmental pollution decreases the biological quality of soil, which is why pesticides and fertilizers are being used in ever-larger quantities. The environmentally friendly solutions to these...
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The mechanism of grouting action under the base of bored pile
PublicationThe grouting under the base of bored pile is carried out in order to reduce pile settlement and improve its bearing capacity. The principal aim of grouting is to introduce an initial force between the soil and the pile base. In non-cohesive soil, the grouting can also enlarge the pile base area and therefore improve the base resistance. The example of static load tests on instrumented bored piles installed with and without grouting...
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Phytoremediation of heavy metals by white cabbage
PublicationPhytoremediation is regarded as the cheapest and environmentally most friendly technology for cleaning up soil. The most widespread and most profitable technique is phytoextraction, used mainly for removing heavy metals and radioactive elements from thesoil. Over 400 plant species have been identified as natural metal hyperaccumulators representing about 0.2 % of all angiosperms. Unfortunately, most of these plants are characterised...
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Nanoindentation tests titanium alloy Ti-6Al-4V after interference laser treatment
PublicationThe study aimed was to assess selected mechanical properties of surface layers obtained after interference laser treatment – DLIL of titanium alloy Ti-6Al-4V used for implants. The samples were melted in still air at room temperature, for this purpose Nd:YAG laser was used, the number of laser shots was variable. Next, nanoindentation tests were performed, based on which Young’s modulus and nanohardness in the obtained surface...
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Random field model of foundations at the example of continuous footing
PublicationThe purpose of the paper is to indicate an efficient method of foundation settlement analysis taking into account the variability of soil properties. The impact of the random variable distribution (Gauss or Lognormal) describing soil stiffness on foundation deposits was assessed. The Monte Carlo simulation method was applied in the computations. The settlements of the strip foundation with the subsoil described by a single random...
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Mechanical Behavior of Plastic Strips-Reinforced Expansive Soils Stabilized with Waste Marble Dust
PublicationExpansive soil needs to undergo treatment to be used as safe foundation soil for roads and buildings. From environmental conservation and economical point of view, the usage of agricultural and industrial wastes is the best option. In this study, the effects of utilizing plastic waste and marble waste dust on the engineering properties of expansive soils were examined. Various laboratory tests were carried out on sampled expansive...
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Mechanical Behavior of Plastic Strips-Reinforced Expansive Soils Stabilized with Waste Marble Dust
PublicationExpansive soil needs to undergo treatment to be used as safe foundation soil for roads and buildings. From an environmental conservation and economical point of view, the usage of agricultural and industrial wastes is the best option. In this study, the effects of utilizing plastic waste and marble waste dust on the engineering properties of expansive soils were examined. Various laboratory tests were carried out on sampled expansive...
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Stiffness of cold-recycled mixtures under variable deformation conditions in the IT-CY test
PublicationStiffness modulus belongs to the most important properties describing the cold-recycled mixtures (CRM) in terms of their usability in road pavement structures. Previous research proved that this property is strongly dependent on the scheme and conditions of the test (temperature and time of loading) and the time that has passed since the compaction of the specimen or pavement layer. It is a result of the influence of two different...
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Experimental and Numerical Investigation of Tensile and Flexural Behavior of Nanoclay Wood-Plastic Composite
PublicationIn this study, the effect of wood powder and nanoclay particle content on composites’ mechanical behavior made with polyethylene matrix has been investigated. The wood flour as a reinforcer made of wood powder was at levels of 30, 40, and 50 wt.%, and additional reinforcement with nanoclay at 0, 1, 3, and 5 wt.%. Furthermore, to make a composite matrix, high-density polyethylene was used at levels of 70, 60, and 50% by weight....
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Discussion of “Stress-Displacement Response of Sand–Geosynthetic Interfaces under Different Volume Change Boundary Conditions” by Aliyeh Afzali-Nejad, Ali Lashkari, and Alejandro Martinez
PublicationThe influence of normal stiffness of interface on the interpretation of shear box tests
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Comparitive study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels
PublicationIn the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation...
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AN ALTERNATIVE WAY OF DETERMINING MECHANICAL PROPERTIES OF WOOD BY MEASURING CUTTING FORCES
PublicationThe cutting force is an energetic effect of splitting material, and might be therefore considered from a point of view of modern fracture mechanics. The dedicated mathematical model developed for description of the wood cutting has been developed here on the base of fracture theory, and includes work of separation (fracture toughness) in addition to the material plasticity and friction. The effect of the cutting edge dullness is...
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Damped forced vibration analysis of single-walled carbon nanotubes resting on viscoelastic foundation in thermal environment using nonlocal strain gradient theory
PublicationIn this paper, the damped forced vibration of single-walled carbon nanotubes (SWCNTs) is analyzed using a new shear deformation beam theory. The SWCNTs are modeled as a flexible beam on the viscoelastic foundation embedded in the thermal environment and subjected to a transverse dynamic load. The equilibrium equations are formulated by the new shear deformation beam theory which is accompanied with higher-order nonlocal strain...
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Equivalent single-layer models in deformation analysis of laminated multilayered plates
PublicationThe performance of selected Equivalent Single-Layer (ESL) models is evaluated within several classical benchmark tests for linear static analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation theory (FOSD) with some modifications incorporated including a correction of the transverse shear stiffness and an application of zig-zag type functions. Seven...
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Structured deformation of granular material in the state of active earth pressure
PublicationThe paper focuses on the ability of granular materials to undergo structured deformation by analysing the data from the retaining wall model tests and discrete element simulations. The structured deformation means the movement of a granular material which produces a stable, regular pattern of multiple shear bands. The paper's primary purpose is to study this kind of deformation for the selected data representing the state of active...
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Laboratory assessment of permeability of sand and biopolymer mixtures
PublicationLaboratory assessment of permeability of sand and biopolymer mixtures. This research presents a method of creating seepage barriers in a sandy soil using biopolymer additives (biosubstance), which consist of polysaccharides and water. Polysaccharides strongly interact with water to produce a viscous suspension. The paper aims to investigate the infl uence of a biosubstance employed in a highly permeable sandy soil. Amount of the...
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Numerical Analysis of Recharge Rates and Contaminant Travel Time in Layered Unsaturated Soils
PublicationThis study focused on the estimation of groundwater recharge rates and travel time of conservative contaminants between ground surface and aquifer. Numerical simulations of transient water flow and solute transport were performed using the SWAP computer program for 10 layered soil profiles, composed of materials ranging from gravel to clay. In particular, sensitivity of the results to the thickness and position of weakly permeable...
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MODELLING OF CUTTING BY MEANS OF FRACTURE MECHANICS
PublicationThe suitability of modern fracture mechanic theory was proved for the estimation of the cutting force and the cutting specific resistance. This paper shows modification of Ernst-Merchant theory and its application for determination some other properties of wood sample. This theory is acceptable for evaluation of shear yield stresses and shear plane angle. Sawing by gang saw machine was used as a process similar to the orthogonal...
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Modelling of cutting by means of fracture mechanics
PublicationThe suitability of modern fracture mechanic theory was proved for the estimation of the cutting force and the cutting specific resistance. This paper shows modification of Ernst-Merchant theory and its application for determination some other properties of wood sample. This theory is acceptable for evaluation of shear yield stresses and shear plane angle. Sawing by gang saw machine was used as a process similar to the orthogonal...
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Cutting model parameters from frame sawing of natural and impregnated Scots pine (Pinus sylvestris L.)
PublicationIn this paper, absolute and density normalized cutting model parameters of natural and impregnated Scots pine (Pinus sylvestris L.) are shown and a method for the calculation of their corresponding material properties in the principal material directions of wood is presented. The parameters were determined from measurements of cutting power on a sash gang saw, and are in detail the fracture toughness and the shear yield strength...
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Permeability of sandy soils estimated from particle size distribution and field measurements
PublicationAccurate estimation of soil permeability is crucial in many geotechnical applications. Empirical and theoretical equations based on soil particle size distribution (PSD) offer a fast and cheap way for preliminary estimation of permeability in granular soils, however the results obtained from various formulas available in the literature often show significant discrepancies. While several comparative studies on this topic have been...
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Stability Assessment of Coastal Cliffs Incorporating Laser Scanning Technology and a Numerical Analysis
PublicationWe investigated the cli coast in Jastrzebia Gora, Poland. The measurements that were taken between 2014 and 2018 by applying terrestrial, mobile, and airborne laser scanning describe a huge geometric modification involving dislocations in a 2.5 m range. Dierential maps and a volumetric change analysis made it possible to identify the most deformed cli’s location. Part of the monitoring of coastal change involved the measurement...
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White cabbage in the biofumigation process- expectations and perspectives
PublicationHealth risks related to common use of pesticides and artificial fertilizers raised the interest in alteranative methods of crop protection, among them biofumigation is becoming the most promising. In this process certain natural compounds, mainly degradation products of glucosinolates produced by Brassica species are used to combat pests and microorganisms attacking crops. Increased synthesis of these bioactive compounds can be...
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O problemie kolmatacji geowłóknin stosowanych w drenażach
PublicationSystemy drenażowe występujące przy obiektach drogowych są niezwykle istotnym elementem tych budowli. Jednym z materiałów, które obecnie powszechnie stosowane są w systemach drenażowych są geowłókniny. Ich zadaniem jest zabezpieczenie odwadnianego gruntu przed procesem sufozji, jak również ochrona drenażu przed zamuleniem przy jednoczesnym zachowaniu wodoprzepuszczalności. Typową trwałość drenażu, w zależności od rozwiązań, szacować...
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Detection of Toxoplasma gondii oocysts in environmental samples
PublicationToxoplasma gondii is an obligate intracellular parasite that has capacity to infect warm-blooded animals. Human toxoplasmosis is usually asymptomatic, whereas severe complications may occur in immunocompromised patients (e.g. AIDS) or in case of congenitalinfection. One of the sources of acquiring human toxoplasmosis is ingestion of T. gondii oocysts. It is known that newly infected cats can shed millions of oocysts into the environment,...
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An integrated geotechnical and geophysical investigation of landslide in Chira town, Ethiopia
PublicationLandslides pose a significant threat to infrastructure, property, and human lives in many regions worldwide, including Chira town in Ethiopia. This study presents an integrated geotechnical and geophysical investigation aimed at identifying the contributing factors to landslides in Chira town, Ethiopia, with a focus on a recent landslide event. The methodology employed a combination of geotechnical and geophysical techniques to...
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Modyfikacja kompozytów elastomerowych NR za pomocą ligniny i glicerolizatu
PublicationPrzedmiotem opisanych w niniejszym artykule badań są wulkanizaty kauczuku naturalnego. Celem pracy było zbadanie wpływu ligniny oraz glicerolizatu na wybrane właściwości kompozytów zawierających kauczuk naturalny. Strukturę chemiczną przygotowanych materiałów potwierdzono, wykorzystując analizę spektroskopową w podczerwieni (FTIR). Zbadano również właściwości mechaniczne przy statycznym rozciąganiu, twardość, ścieralność oraz odbojność...
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Hydraulic conductivity of a biopolymer treated sand
PublicationThis paper presents results of laboratory assessment of creating seepage barriers in a sandy soil using biopolymer additives (bio substance), which consist of polysaccharides and water. Polysaccharides strongly interact with water to produce a viscous suspension. The aim of the conducted work was to investigate the influence of a biosubstance employed in a highly permeable sandy soil. The amount of the biopolymer used in a sample...