Geotechnical Engineering

 Numerical modeling of soft soil reinforced by rigid inclusions.  Calculation of settlements and stresses under the placement of embankment layers  The settlement at the embankment soil interface has been reduced by 90% compared to a soil without reinforcement.  Despite the problems encountered with elastoplastic calculations, a good distribution of the stresses in the inclusions is obtained. The charge transfer mechanism is well done for the elementary cell. A three-dimensional finite element model was suggested to determine the settlements and stresses of an embankment placed on soft soil reinforced by rigid inclusions. To simplify, the layers of soil and the embankment are supposed to be horizontal in a semi-infinite medium, and the base of the soft soil is supposed to be rigid (bedrock). The interacting elements of the model are supposed to be elastic. The determination of the behavior of the soil-inclusions-embankment system was realized according to the construction phases of the embankment layers. The settlements and stresses were calculated according to the construction phases of the embankment layers. The stress and displacement fields are extracted at the end of each calculation phase. The values are then introduced into the model at the beginning of the next phase. The obtained results are presented in terms of the (settlement) vertical displacements and vertical stresses for the elementary cell and the global model, respectively. This study allows the observation of three-dimensional interactions, the load transfer mechanisms and the interaction between the different zones of the embankment. The numerical calculations are much lower than those measured in situ. A verification calculation on the stresses transmitted by the rigid inclusion shows that only 90% of the total load is applied with the numerical calculation.

Depremlerde binaların yıkılması yapı kalitesinden ve oturduğu zeminin dinamik-statik özelliklerinden ya da derin yeraltı yapılarından kaynaklanabilir. Yapı kalitesi için beton dayanımı belirlenmesi önemli bir adımdır. Beton kalitesi, karot alımı ve laboratuarda tek eksenli basınç dayanımı ile belirlenebilir. Bu durumda karot alınan kolon ya da kiriş tahribata uğrar. Tahribatsız deney yöntemi olan Jeofizik yöntemlerden Ultrasonik P ve S ölçerler ile beton kalitesi ortaya konulabilir. Ultrasonik yöntemle sadece beton dayanımı değil aynı zamanda dinamik elastik parametreler ve Poisson Oranı da belirlenebilmektedir. Bu çalışmada silindir ve küp betonların P ve S dalga hızları ölçülmüştür. Bu beton örneklerinin serbest basınç dayanımları belirlendikten sonra P ve S dalga hızları ile ilişkilendirilerek deneysel bağıntılar geliştirilmiştir. Geliştirilen deneysel ilişki literatür ilişkileri ile karşılaştırmaları yapılmıştır. Sonuç olarak yapıdaki betonu tahrip etmeden dayanımını belirlemek hem ekonomi hem de zaman açısından faydalıdır.

The primary road surface characteristics that affect users are safety, noise and riding quality. Safety particularly relates to surface texture (macro texture), which infl uences water dispersal and ability of a tire to contact the road surface. This paper deals mainly with texture depth contribution to tire pavement contact. A slab mould was designed and built specifi cally of SMA to conduct skid and texture depth tests to simulate the actual fi eld behavior. A stepwise regression analysis was used, to indicate the separate and distinct effect of several aggregate factors such as angularity, type of aggregate, percent of asphalt voids in the mix, density, Polished Stone Value, Particle Index, Surface area, on the skid resistance of the experimental surface mixtures. At 95% confi dence limit, a total of fi ve dependent variables were found to be signifi cantly infl uence texture depth of StoneMasticAsphalt (SMA). Those variables were angularity, coarse aggregate, percent of asphalt, voids in the mixture and density. It may therefore be concluded that the texture depth of SMA has the potential to optimize the contact area between tires and road surface under dry and wet conditions.

The application of waste rubber tires for ground improvement helps to improve the environment by recycling and reusing it as admixtures. This research aims to investigate the shear strength parameters of rubber-sand mixtures. By using crumb rubber with a constant size (425μm), the sand is replaced by different percentages (0, 2.5, 5.0, 7.5, and 10%) of crumb rubber by weight. A direct shear box test is used to determine the shear strength parameters of rubber-sand mixtures with two different controlled densities. The samples were loaded with normal stresses of 20, 40 and 80kPa and were sheared at a rate of 1mm/min. Although, this experiment discovered that crumb rubbers improve the shear strength parameters in loose sand, however, a reduction in shear strength parameters was found in dense sand. Moreover, it was observed that the inclusion of crumb rubbers into sand greatly improve the strain energy of both loose and dense sand. Likewise, rubber has a low unit weight which makes it ...

Rock burst is one of the typical dynamic disasters in coal mining. In order to reveal the mechanism of rock burst from the energy view point, the relationships between the maximum, minimum, and intermediate principal stresses and the concentration coefficients of the gravity stress k1, k2, and k3 are determined through the geostress measurement combined with engineering practice of coal mining. The coal and rock system model based on the tectonic stress is established. The relationship between energy and scale radius of the coal and rock system is determined to reveal the law of energy accumulation, release, and transfer in the coal and rock system. In view of the characteristics of the porous medium in the coal seam, the measures of water injection are put forward to relieve pressure in the coal seam, and the law of water seepage in the process of water injection in the coal seam is studied based on the seepage mechanics. The result shows that the trend of released energy of damage...

Constructing roads in geologically unstable regions such as northern Morocco poses a major challenge. The Tizi Ouadrene sector, located in the Rif External Nappe of the Rif Belt, exemplifies a significant complexity in this issue, with a risk of landslides threatening the road embankments in this area. This study aims to characterize the frequent Cretaceous shales in the study area and analyze the landslides that have occurred on the road embankments cut into these shales. It examines the role of lithology, geometry, tectonics, human activity, and water in these landslides. The geological structure of slopes and their geometric configuration are crucial factors in determining the occurrence, distribution, and other characteristics of these landslides. Defects are controlled by the relative position of sedimentary and tectonic discontinuities, as well as the relative abundance of indurated shales compared to crushed ones. Crushed shales are susceptible to rotational slides, while the indurated ones are prone to planar and wedge sliding. The latter are mainly associated with bedding planes, particularly those oriented N65-80 with slopes facing south and SSE, as well as NW-SE and NE-SW-trending fractures. Hydrological, tectonic, and anthropogenic factors also contribute to the instability.

This paper describes instrumental measurement uncertainties and their influence on the result obtained from determination of rock sample uniaxial compressive strength and deformability. The interdependence of uncertainty contribution is analyzed and guides for improving measurement uncertainty are given. The achieved uncertainties are compared to typical uncertainties in the determination of concrete and metallic material compressive strength and deformability.

In this study, the hydrodynamic characteristics of a novel oscillating water column (OWC) breakwater with a horizontal bottom-plate is numerically and experimentally investigated. A viscous fully nonlinear numerical wave tank (NWT) solved by the open source package OpenFOAM is established under laminar flow conditions. After comparing the numerical results with the experimental ones, the well-validated numerical model is further employed to investigate the effects of the length of horizontal bottom-plate (D), the immersion depth of backplate (d 2 ), the water depth (h) and the wave height (H) on the reflection (C r ) and transmission (C t ) coefficients, dissipation coefficient (C d ) and column-confined energy coefficient (C e ) of the breakwater. The results show that lengthening the bottom-plate can effectively increase the energy dissipation and then lead to lower reflection and transmission coefficients, and a smaller draught of the back-plate can also increase energy dissipation. The water depth has insignificant influence on the hydrodynamic coefficient of long waves, but influences the breakwater performance in short waves. The variation of wave height mainly contributes to the change of reflection coefficient.

Flooding is a natural occurrence hazardous to people and properties and produces environmental and economic losses, especially in flood-prone areas. This study will be used to assess flood risk in the Bangko and Masjid watersheds. To analyze it, flood hazard mapping is arranged by slope, land cover, elevation, rainfall, buffer zone, and soil type, which is done with the help of a Geographic Information System (GIS), specifically QuantumGIS (QGIS). This system tool assesses each variable utilizing satellite spatial data and categorizes the vulnerability being very high, high, medium, low, and very low. Each map arrangement value is combined using an overlay value to determine the flood susceptibility. According to the mapping results, the Bangko and Masjid watersheds are highly vulnerable to flooding. Based on the results of the mapping, in the Bangko watershed 61% of the total area is vulnerable to flooding, and 20% has high to very high vulnerability, while in the Mosque watershed ...

Mangroves are important from ecological and social perspectives. Mangrove restoration projects are increasingly recognized as allies to achieve sustainable development efforts and mitigation and adaptation to climate change. Forest owners at the community level can establish costeffective initiatives to comply with Mexican legislation for the registration of forest carbon projects and the certification of the increase in the aerial carbon stock over time. However, mangrove restoration projects do not produce positive results from technological bases alone, but require community participation, appropriate government structures, and alignment of objectives and goals of local and external actors. This study illustrates the socioenvironmental bases behind the hydrological restoration and community management of a mangrove in the Yucatan Peninsula, Mexico, as well as the socio-environmental benefits obtained. The results and discussion advance knowledge on ecological restoration by detailing the hydrological restoration approach in mangroves associated with meteorological disturbances.

A parameter analysis is performed on an analytical penetration model which has been recently developed. Figures are plotted to show how the disturbed zone size, parameters of displacement and stress fields and dynamic section pressure are dependent on soil compressibility, shear strength and mass density. Main results are presented and discussed.

In ensuring the quality of infrastructure, the role of land as support for buildings is very crucial. Road transportation infrastructure located in Sumberagung Village, Wates Subdistrict, Kediri Regency, has often experienced estimated damage due to unsuitable soil surface layer specifications. On this occasion, the authors conducted a research study on soil characteristics at the location. They carried out experiments to repair damage to the soil surface layer using a combination of additive TX -300 media in the amount of 5%, 10%, and 15%. The method used was to test soil particles at the location and perform Index Plastic and Proctor tests to measure soil improvement efforts using TX-300 additives. The study results stated that the soil in the area had the criteria of GP (poorly graded gravel) and SP (poorly graded sand). On the USCS theory and the Montmorillonite category in the ASTM classification. The soil plastic index value was 19.37%. The dry volume weight (ɣd) of the Proctor after being converted to the importance of the contents was 3.61 gr/cm3. The Plastic Index value increased to 34.44% after the additive TX-300 combinations. In the 10% combination, the test value (ɣd) of Proctor increased to 4.59 gr/cm3.

Aims Root exudates contain polymers that form crosslinks and can create a jelly like substance known as mucilage, which adheres to soil and thus promotes the formation of rhizosheaths, i.e. soil that remains attached to the roots after gentle shaking. We hypothesized that rhizosheath formation is optimal at an intermediate chia seed mucilage concentration and water content, but that its formation is limited at both a high concentration of chia seed mucilage and under dry conditions as well as at a low concentration Responsible Editor: Jiayin Pang.

On-going monitoring of deformation of dams is critical to assure their safe and efficient operation. Traditional monitoring methods, based on in-situ sensors measurements on the dam, have some limitations in spatial coverage, observation frequency, and cost. This paper describes the potential use of Synthetic Aperture Radar (SAR) scenes from Sentinel-1A for characterizing deformations at the Mosul Dam (MD) in NW Iraq. Seventy-eight Single Look Complex (SLC) scenes in ascending geometry from the Sentinel-1A scenes, acquired from 03 October 2014 to 27 June 2019, and 96 points within the MD structure, were selected to determine the deformation rate using persistent scatterer interferometry (PSI). Maximum deformation velocity was found to be about 7.4 mm·yr−1 at a longitudinal subsidence area extending over a length of 222 m along the dam axis. The mean subsidence velocity in this area is about 6.27 mm·yr−1 and lies in the center of MD. Subsidence rate shows an inverse relationship with...

Al-Batin alluvial fan is one of the largest alluvial fans in Iraq, especially in the Iraqi Southern Desert. Its eastern and southern limits form parts of the Iraqi-Kuwait international borders. The fan is deposited by Wadi Al-Batin, the last apex being on the southern limits of the main wide depression formed by the active Abu Jir-Euphrates Fault Zone. The main trend of the fan is almost SW-NE. The length and the maximum width of the fan are 110.192 Km and 119.1 Km, respectively, whereas the slope along its length is 0.7˚. The fan is covered by gypcrete sheet with thickness varying from (0.5 -1.5) m. Four stages were recognized within the fan, which is dated to be Pleistocene in age. The four stages are marked by clear height differences. The deposition of the alluvial fan is highly affected by the activity of the active Abu Jir-Euphrates Fault Zone, which is represented on the surface as a wide shallow depression in which the fan is laid down by Wadi Al-Batin. The continuous deposition of the fan has affected the course of the Euphrates Formation within Hammar Marsh and also the course of Khor Al-Zubair in its upper reaches south of Al-Qurna, where the Euphrates and Tigris rivers merge together. Also there is a trace of ancient distributary of the Euphrates River that was flowing directly to the Arabian Gulf, through an estuary, which is abandoned and does not exist anymore.

The two proposed conceptual models explaining partially saturated flow from soil into fractured rock in the intermediate fractured vadose zone have not been confirmed due to the difficulty involved in observing the soil-rock interface in situ. To address that challenge, this paper presents a series of newly developed physical experiments using a geotechnical centrifuge model of sand overlying a single dry clean smooth vertical fracture. The model shows the development of a perched water system and a saturated wetting front that progresses transversely along the interface, while breaching through the interface occurs via multiple point sources. The dominant flow mechanisms within the fracture comprise droplets, discontinuous rivulets with droplet formation, and continuous rivulets. A maximum drainage area of 30% of the width of the fracture contributes to the flow in the model, and this drainage area decreases with depth due to the merging of oscillating rivulets in the upper regions of the fracture. The presence of evidence supporting both conceptual models shows that a combined conceptual model is required to accurately explain partially saturated flow at the soil-rock interface.

In railway tracks, ballast fouling due to fine materials mixing has been identified as a challenging issue. In this research, deformation characteristics of sand-gravel mixtures, simulating fine-ballast mixtures, were studied using laboratory and DEM-simulated triaxial compression tests. The DEM simulations were done in Yade, an open source developed based on DEM. Initially, void ratio characteristics of sand-gravel mixtures were studied. Then, triaxial compression tests were conducted for the specimens of 50% and 80% of relative densities. The void ratio results indicated that, initially, void ratios decreased with %sands. After reaching the minimum void ratios, void ratios increased with %sands. The triaxial test results indicated that, on average, similar behaviour in stress-strain curves, where, at initial %sands, stress-strain curves became higher and then, stress-strain curves became smaller, though it was slightly different in laboratory tests.

SUMMARYThere are several alternatives to evaluate seismic damage‐cracking behavior of concrete arch dams, among which damage theory is the most popular. A more recent option introduced for this purpose is plastic–damage (PD) approach. In this study, a special finite element program coded in 3‐D space is developed on the basis of a well‐established PD model successfully applied to gravity dams in 2‐D plane stress state. The model originally proposed by Lee and Fenves in 1998 relies on isotropic damaged elasticity in combination with isotropic tensile and compressive plasticity to capture inelastic behaviors of concrete in cyclic or dynamic loadings. The present implementation is based on the rate‐dependent version of the model, including large crack opening/closing possibilities. Moreover, with utilizing the Hilber–Hughes–Taylor time integration scheme, an incremental–iterative solution strategy is detailed for the coupled dam–reservoir equations while the damage–dependent damping st...

Overpressure within a circular magmatic chamber embedded in an elastic half space is a widely used model in volcanology. However, this overpressure is generally assumed to be bounded by the bedrock tensile strength since gravity is neglected. Critical overpressure for wall failure is thus greater. It is shown analytically and numerically that wall failure occurs in shear rather than in tension, because the Mohr–Coulomb yield stress is less than the tensile yield stress. Numerical modelling of progressively increasing overpressure shows that bedrock failure develops in three stages: (1) tensile failure at the ground surface; (2) shear failure at the chamber wall; and (3) fault connection from the chamber wall to the ground surface. Predictions of surface deformation and stress with the theory of elasticity break down at stage 3. For wall tensile failure to occur at small overpressure, a state of lithostatic pore-fluid pressure is required in the bedrock which cancels the effect of gr...

Pretensioned spun high strength concrete (PHC) piles are a commonly used type of pile, while approximately 60% of the pile's strength is only used in the design bearing capacity. Because of the limited support capacities of PHC piles, applying PHC piles to high-rise buildings or soft ground is inefficient. Extended end (EXT) piles are a new type of pile that can reduce the waste of pile strength and increase the ground bearing capacity. This study investigated the behavior of EXT piles through a field test and it was confirmed that the bearing capacity of the EXT pile is better than the PHC pile. The increased bearing capacity of EXT piles also influenced work duration and project cost.

Pre-tensioned, spun, high-strength concrete (PHC) piles are the most commonly used type of pile in South Korea. Approximately 60% of the pile's strength is used in the design bearing capacity, and the rest is simply residing in the ground. Increasing the ground bearing capacity is crucial to reduce waste of the pile strength and to improve efficiency. Extended end (Ext) piles are a new kind of composite pile that can overcome the weakness of PHC piles. This study investigates the behaviour of Ext piles. Through field testing, it is confirmed that the bearing capacity of Ext piles is better than PHC piles by about 35% to 50%. Based on the study findings, the Ext pile design reduces the number of piles by around 38% compared to the PHC pile design through application in a selected construction site. The increased bearing capacity of Ext piles affects both work duration and project cost, which are 25% and 14% decreased, respectively.

Backwashing rapid sand filters causes inadvertent displacement of filter media grains from their previous depths. This displacement can affect the hydraulic function of filters by mixing or segregating media grains, and the function of biofilters through displacement of active biomass and coatings from proper depths. This study quantifies grain displacement in a pilot-scale filter using tracer grains of colored sand, glass beads, anthracite and garnet to determine the effect of grain size, density and shape on grain displacement. Statistical moments are used to describe the depth distributions resulting from displacement during backwashing. Results show that significant grain displacement occurs during backwash consisting of air scour, air-and-water wash and sub-fluidization water-only wash. Here, displacement is largely independent of grain size, density and shape. When fluidization backwash is used, greater displacement and more dependence on grain characteristics is seen. A varie...

The paper presents the results of a characterization of kinetic characteristics of pozzolanic reaction with the aim to investigate the time-dependent modification of clay properties as a consequence of mixing with lime. Results of chemical analyses are in agreement with the increase of mechanical properties and with the observed microstructure modifications up to one year of curing time. The rate of development of pozzolanic reactions seems to be almost constant while the time required for their completion is dependent on the lime content. Pozzolanic products are responsible for the time reduction of swelling strain upon saturation as well as for the increases of yielding stress, stiffness and hydraulic conductivity. However, the data analysis proves that a significant component of settlement measured during loading may be induced by the secondary compression process (creep). These results are significant for the prediction of the long-term behaviour of the stabilized soil.

The stability of foundations soils could represent a clear and present threat for the conservation of even well preserved buildings, particularly for Architectural heritage conservation and land art heritage. A dramatic case is the presence of collapsible metastable sands as foundation soils, as it occurs in the sacral complex Valle dei Templi in Agrigento. This site listed by UNESCO, stands on a crest of a calcarenite cuesta, overlaying a layer of these sands. When the collapsible sand is dry, the structure is strong enough to bond the sand particles together. When the sand becomes wet, a de-structuration mechanism occurs and the soil's strength is compromised. This paper has a twofold aim: (1) to gain a better understanding of the kind of bonding forces between the textural components of the collapsible metastable sand and (2) to identify a proper consolidant, that could combine the compatibility of inorganic systems and the performance of polymeric materials, paying attention to the environmental issues related to this site. Soaking tests have been performed by submerging sand samples in different solvents in order to verify the role of water menisci in mechanical stability of the sand highlighting a perfect stability using a non polar solvent. Sand samples have been consolidated by using poly ethylene glycol and nanosilica. Oedometer tests on consolidated and untreated samples have been used to verify the reduction of collapse potential induced by the treatment with the proposed mixtures.

Soils are generally of two types-expansive soils such as Black Cotton Soil (BCS) and non expansive soils like Red Earth Soil (RES). This paper describes the strength and consolidation behavior of Red Earth Soil treated with lime. It is found from compaction and unconfined compressive strength test that Red Earth Soil with 3% lime is considered as optimum. On the basis of unconfined strength test it was found that addition of optimum lime to RES increases strength by 5 times when compared with soil alone at 30 days curing. Addition of 3% lime to RES reduces the final voids ratio by 4% and coefficient of compressibility by 39% when compared with soil alone.

Safetyofabridgedependsonthedepthandvolumeoflocalscourarounditspiers.The existence of parallel railway-bridge and road-bridge or a newly constructed bridge by the side of an old bridge gives rise to a situation, where the interference of the presence of an upstream pier and a downstream pier is prevalent. The upstream pier could primarily influence the scour at a downstream pier in two ways: (1) upstream pier modifies the flow field in the wake flow region that acts as an approaching flow for the downstream pier to scour and (2) the sediment that is scoured from the upstream pier is being fed to the scour hole at the downstream pier. Thepresentstudyattemptstoquantifythe effectofthe mutualinterferenceof upstreamand downstream piersonlocalscourat both thepiers.Themutualinterferenceofthepiersonlocalscourdependsontheshapeofthepiers,flowvelocity,flowdepth, sediment size, andoblique distance between the piers andflow oblique angle Thestudydeals with an experimental study of local scour aro...

A new constitutive model for the soil-water retention behaviour of unsaturated soils is proposed, able to reproduce the main drying and wetting paths, the cyclic retention behaviour and its dependence on the specific volume. The most significant aspect is the inclusion of the evolution, with the specific volume, of the degree of saturation when suction tends to zero in wetting paths considering the presence of entrapped air bubbles. The model is used to reproduce with success the drying/wetting cycles of two Pearl clay samples.

Cracking due to desiccation can compromise the behaviour of earth structures built with compacted clayey soils by promoting water access and consequent volume changes on further wetting. Tensile strength therefore is important to be considered when studying the behaviour of such structures, and in particular its dependence on the degree of saturation or water content. The influence of water content in tensile behaviour of compacted marls was investigated by performing diametral compression tests (Brazilian splitting tests), where axial deformations were measured besides strength. The samples were prepared by compaction at optimum point using standard compaction energy (optimum water content 16%) and then dried by vapour equilibrium to reach water contents between 5% and 16%. The correspondence between water content and suction was done by using the drying branch of the water retention curve, measured using WP4 equipment (Water Dewpoint Potentiometer). Good relationships were found b...

A consideração das ações atmosféricas no dimensionamento de estruturas geotécnicas tais como taludes, aterros, barragens de aterro e fundações, justifica-se quando as deformações devidas a ciclos de molhagem e secagem (ciclos de sucção) ultrapassam valores que podem comprometer a funcionalidade destas estruturas. Para o cálculo das deformações devidas às ações atmosféricas é necessário, primeiro, quantificar essas ações no solo, tarefa onde se tem que considerar as ações atmosféricas e as características hidráulicas do solo para o seu grau de saturação e, segundo, recorrer a modelos constitutivos para solos parcialmente saturados pois a sucção tem que ser incluída como variável de estado. Como exemplo descrevem-se alguns casos estudados no IST, depois de se apresentar alguns casos que justificam a consideração das ações atmos féricas na sua análise.

Soil-Cement mixtures are used in several geotechnical applications and consist of artificially structured materials with stable fabric due to the presence of artificial bonds, which are the hydrated cement minerals coating the aggregates (soil particles). An extensive experimental study was performed on samples of an artificially cemented silty sand prepared by adopting three different dosages of cement and different water-cement ratios for each dosage. Realistic values for the dosages and water-cement ratios were adopted considering soilcement mixtures performed by compaction or by grout injection. The unconfined compressive strength (UCS) and indirect tensile strength (ITS) of the mixtures were measured for different curing times. The values found were related to the water-cement ratio adopted for the mixing process, because of the dependency between the porosity of cement and the geometry of the bond minerals observed in electron scanning microscope images. The bond geometry varied considerably depending on the amount of water used in the preparation, particularly in the case of low cement dosages. The definition of degree of bonding was adopted to describe the evolution along curing time of UCS and ITS considering the values measured after 3 days of curing as reference points. This degree of bonding is useful for the definition of constitutive models for artificially structured materials. This parameter was indirectly related with the bond geometry; that is, the paths of strength evolution found were similar for samples with dispersed bonds. The improvement of tensile strength and compressive strength are correlated through a constant, independent of the dosage and water-cement ratios adopted for the mixture. Several authors have found identical values for this constant when studying compacted sand-cement mixtures. The particular structure resulting from the preparation process adopted does not affect this constant, however it affects the maximum UCS and ITS achieved for each cement dosage studied. This maximum depends on the water-cement ratio, and therefore this ratio is an important design parameter to be considered when prescribing compacted or grouted solutions.

In general, the prescription of the amount of water used in soil-cement mixtures is done to define the optimal compaction conditions for bases and subbases, or to ensure the fluidity necessary for a good mixture by injection. A better knowledge about the hydraulic behaviour of the resulting mixtures may be useful in service conditions, when permeability is important or when the layers are exposed to wetting and drying cycles. The relationship between saturated hydraulic permeability, coefficient of water absorption by capillarity and water retention properties were investigated for an artificially cemented sand prepared with different and realistic cement dosages, and with different water-cement ratios for each dosage. The water-cement ratio was considered in the analysis because it affects porosity and pore size distribution of the cement paste, and consequently tortuosity. Low values of this ratio mimic compacted sand-cement mixtures and large values simulate grouted sands. The dosages adopted simulate those used in pavement layers and obtained in grouted bodies. The results of an extensive set of experimental tests, performed to determine the hydraulic properties mentioned, are interpreted in the paper considering the presence and structure of the hardened cement paste. The materials prepared with low water-cement ratio have higher permeability and different water retention properties from those prepared with high ratios. Nevertheless, the water used in the hydration of the cement also affects the porosity and tortuosity of the hardened paste and may increase porosity if grout is very fluid. This study contributes to increase the knowledge about the effects of design parameters cement dosage and watercement ratio on the hydraulic behaviour of the mixtures, which may be relevant when evaluating water retention and percolation.

Some embankments on the A10 motorway, in Portugal, were built with marls. A lime treatment was prescribed for the material placed on the shoulders to protect it from the actions of the weather. This zoned profile design solution was a cheaper alternative to giving the embankment a full treatment. Two major concerns emerged during the construction, which motivated the research presented in this paper. The first was the possibility of cracking induced by the different stiffness of the core and treated shoulders, thus providing access of rain water to the core material, which was exactly what the treatment intended to avoid. The second was the difficulty in estimating the amplitude of long-term deformations, which can be expected due to the evolving nature of the marls used. The research program included the instrumentation of a selected embankment and laboratory tests on samples of treated and untreated compacted marls. The instrumentation allowed the measurement of vertical displacements and water content distribution to investigate if long-term displacements would be a concern during operation. The laboratory tests characterized the hydro-mechanical behavior of the material and its changes with the lime treatment. This research also stimulated discussion of some ideas about the expected performance of the embankment during its life cycle.

• Loading speed does not affect the ultimate point and total bearing capacities of the pile significantly. • The base, shaft, and total bearing capacities of piles mobilized at different settlement values. • The base and total capacities of piles decrease 65 to 75% when the dry soil becomes saturated. • Experimental Nq coefficients were smaller than coefficients of Vesic and Meyerhof but closer to Janbu's. • Nq value depends on the internal friction angle of soil, effective stress, pile diameter, and saturation degree. • In dry and saturated sands, Nq value decreases since the pile length/pile diameter ratio increases.

Karst springs play a central role in Austria’s water supply. This paper aims to provide an overview of the karst springs of Lower Austria, analysing statistical correlations of spatial distribution, discharge, electrical conductivity (EC), and temperature. As part of a project with the provincial government of Lower Austria, older data from numerous studies have been combined with the self-generated data in a GIS database. This database contains data on 2056 karst springs. Most of the recorded springs are located in the Northern Calcareous Alps, although karst springs also occur in the Central Alpine Permomesozoic, the Waschberg zone and the Bohemian Massif, some of which are also of regional importance for drinking water supply. Chemical analyses show that limestone, dolomite and mixed springs are widespread in Lower Austria and occur with similar frequency. Gypsum springs, which are characterised by a significantly higher total mineral-isation, are also of regional importance. The...

This report has three main areas of interest. First, a brief discussion on the need for the Indiana HARN and why this was an important task. Second, a summary of the details surrounding the Indiana HARN survey. Finally, the station description of the HARN point in your county is attached with a map of the general area surrounding this point. We have also included a discussion on monument preservation with tips on how keep the high accuracies associated with your point(s). Also, a section is included on how the HARN is being used in Indiana with a few success stories. We have included three tables listing all of the HARN points in Indiana organized in different ways for easy location. We encourage you to visit the web site we have dedicated to the Indiana HARN when conducting research for surveys in your county. Each point is listed with the station description and map, as in this report, but it also has the NGS Data Sheet with the current coordinates for each point. The web address is Located at . The data sheets are accessed by clicking on the PID, and the station description is accessed by clicking on the four-character ID. It is our hope that your LPA will fmd this report useful and informative. We encourage you to use the web site for information on using the HARN or contact us with any questions concerning the HARN at the number listed below.

This paper evaluates in-soil tensile load-strain characteristics of geogrids with the help of a custom designed and developed in-soil tensile setup in the laboratory. Displacement controlled in-soil tensile tests were carried out to evaluate the effect of normal stress, soil type, and presence of sand-sandwiched layer, on the tensile load-strain characteristics of geogrid. Confinement of geogrid within the soil and application of normal stress were found to increase the mobilized tensile load and secant tensile stiffness of geogrid. Secant stiffness improvement factors were determined to quantify the improvement in tensile load-strain characteristics of geogrid under confinement, on comparison to in-isolation values. Geogrid was observed to exhibit lower secant tensile stiffness when embedded in marginal soil, moist-compacted at wet of optimum. However, the concept of sand-sandwiched geogrid was found to improve the tensile load-strain behaviour of geogrids embedded in marginal soil compacted at wet of optimum.

This paper examines the stability of geotextile-reinforced slopes when subjected to a vertical load applied to a strip footing positioned close to the slope crest. Vertical spacing between geotextile reinforcement was varied while maintaining a constant slope angle, load position, soil density and geotextile type. Small-scale physical tests were conducted using a large beam centrifuge to simulate field prototype conditions. After the model was accelerated to 40g, a load was applied to the strip footing until slope failure occurred. Digital image analysis was performed, using photographs taken in-flight, to obtain slope displacements and strain distribution along the reinforcement layers at different loading pressures during the test and at failure. Stability analysis was also conducted and compared with centrifuge model test results. The vertical spacing between reinforcement layers has a significant impact on the stability of a reinforced slope when subjected to a vertical load. Less vertical distance between reinforcement layers allows the slope to tolerate much greater loads than layers spaced further apart. Distributions of peak strains in reinforcement layers due to the strip footing placed on the surface of the reinforced slope were found to extend up to mid-height of the slope and thereafter they were found to be negligible. Stability analysis of the centrifuge models was found to be consistent with the observed performance of geotextile-reinforced slopes subjected to loading applied to a strip footing near the crest.

This paper reports the results of laboratory study performed on expansive soil reinforced with geofibers and demonstrates that discrete and randomly distributed geofibers are useful in restraining the swelling tendency of expansive soils. Swelling characteristics of remoulded expansive soil specimens reinforced with varying fiber content (f ¼ 0.25% and 0.50%) and aspect ratio (l/b ¼ 15, 30 and 45) were studied. Onedimensional swell-consolidation tests were conducted on oedometer specimens. Reduction in heave and swelling pressure was the maximum at low aspect ratios at both the fiber contents of 0.25% and 0.50%. Finally, the mechanism by which discrete and randomly distributed fibers restrain swelling of expansive soil is explained with the help of soil-fiber interaction.

Most common cause of referral to similar mental health services as s early as 1987, Kazdin identifies anti-social behavior in children as a predominant and serious clinical problem. Many children have symptoms of social isolation Bauminger et al. [9], reduced academic performance and progress at school, attention deficit disorder, hyperactivity, which in adolescence are manifested with symptoms of delinquency and antisocial behavior Reid et al. [10], McGilloway [11] On the other hand, research shows that the presence of one or more children with disorders is psychologically burdened by parents , Myers [13] report that the autistic child's parents experience the constant anxiety and the burden of Abstract Theoretical Background: Research indicates that the presence of one or more children with developmental and behavioral disorders increase the psychological burden of parents Purpose/Objective: The objective of this study is the investigation of the burden of parents with children with Pervasive Developmental Disorders [PDD] and Behavioural Disorders [BD] who come to Children's Mental Health Centers and Advisory Stations. Materials and Methods: 104 parents [either mother or father] of children of both sexes suffering from Pervasive Developmental Disorder [PDD] took part in the research, and an additional 25 parents [either mother or father] of children of both sexes with Behavioral Disorders [BD] also participated. The questionnaire was used for the data collection was the Zarit Burden Interview. Results: More specifically it is statistically borderline evident and important (p=0,057) that mothers on average (11, 74±5, 00) experience the intensity of the care-giving role more profoundly as opposed to the men (9, 93±6, 03). Additionally, it is statistically significantly evident (p=0,007) that mothers on average (8, 41±4, 00) experience the relationship deprivation more profoundly than their male counterparts (6, 39±4, 24). Also, it is statistically significantly evident (p=0,036) have on average (39, 05±16, 54) a higher total care giving coping burden in relation to men (33, 07±18, 84). Parents with children that suffer either from pervasive developmental disorders or behavioral disorders, experience a psychological burden. Parents with children that suffer either from pervasive developmental disorders have higher psychological burden than parents with children with behavioral disorders. Mainly it is noteworthy that mothers are burdened more than fathers.

The roasting technique is considered one of the coffee processing stages that can continue to be developed for sustainable innovation, both in the process and in the equipment. It is an important factor that determines the coffee’s quality. This study aimed to assess the impact of the roasting method using a hot air roaster on the physicochemical properties of Cisalak robusta coffee. The method for roasting green coffee beans was conducted under six conditions based on the speed and level of roasting: slow-light, slow-medium, slow-dark, fast-light, fast-medium, and fast-dark. The bulk density, hardness of coffee beans, water content and lightness of coffee powder decreased as the roasting level increased, whereas the ash content, pH level and caffeine content increased. The slow roasting speed produced a coffee with a lower water content and hardness, whereas the ash content, L values and pH level was higher than fast roasting method. Based on the results, robusta coffee which was r...

Física é a ciência exata que tem por objeto de estudo os fenômenos que ocorrem na natureza. Através do entendimento dos fenômenos da natureza, podemos entender como as coisas acontecem em nosso dia-a-dia. A Física tem grande importância para a sociedade, pois uma infinidade de equipamentos que utilizamos hoje, em nosso cotidiano (como rádios, tvs, celulares, mp3, computadores, laser, dentre outros), foram desenvolvidos utilizando conceitos e Leis da Física. É a ramo da Física que estuda os movimentos. Esse estudo está subdividido em duas partes: -a Cinemática, que estuda o movimento de corpos ou partículas sem se preocupar com as causas que dão origem ao movimento; -a Dinâmica, que estuda as causas dos movimentos. CINEMÁTICA: Partícula: é todo corpo cujas dimensões não interferem no estudo de um determinado fenômeno físico. Corpo Extenso: é todo corpo cujas dimensões interferem no estudo de um determinado fenômeno. Referencial: é um ponto fixo (ou objeto) pré-determinado, a partir do qual se pretende analisar se um corpo (ou partícula) está em movimento ou não. É indispensável para se determinar a posição de um objeto. Sistema Internacional de Unidades (S.I): é um conjunto de unidades de medida onde se adotam unidades pré-escolhidas para as grandezas físicas comprimento, massa e tempo. O padrão mais comum utilizado na Brasil é o M.K.S., sendo: comprimento → metro(m); massa → quilograma (Kg); tempo → segundo(s). Velocidade Média (V m ): é a razão entre a distância percorrida por um corpo (ou partícula) e o tempo gasto em percorrê-la. Matematicamente, podemos calcular a Velocidade Média de um corpo ou partícula utilizando: V m = ∆ ∆ ∆ ∆S , onde: Vm = Velocidade Média (m/s); ∆ ∆ ∆ ∆t ∆S = Variação da Posição (m); → corresponde à distância Percorrida ∆t = Variação do Tempo (s). → corresponde ao intervalo de tempo gasto A unidade de velocidade média no Sistema Internacional é o metro/segundo (m/s). Em Física, a letra grega ∆ significará, aqui no Ensino Médio, sempre uma Variação. Desta maneira, poderemos escrever, sempre que for conveniente, essa variação como sendo uma subtração entre os valores finais e os valores iniciais da mesma grandeza. Por exemplo: Variação do tempo (∆t) pode ser escrita matematicamente como instante de tempo final menos o instante de tempo inicial (t f -t i ). A variação da velocidade de uma partícula (∆v) pode ser escrita matematicamente como sendo a velocidade final menos a velocidade inicial da partícula (v f -v i ). Podemos aplicar esse conceito também à Velocidade Média. Fazendo isso, podemos escrever matematicamente outra forma de calcular a Velocidade Média de um corpo: v m = s f -s i , onde: vm = velocidade média (m/s); t f -t i sf = posição final do corpo (m); si = posição inicial do corpo (m); tf = instante de tempo final (s); ti = instante de tempo inicial (s).

The presence of moisture in masonry is crucial because it causes and exacerbates various deterioration mechanisms, such as crystallization of salts, mechanical stresses due to freeze-thaw cycles, biological degradation, etc. The assessment of the water content is critical for cultural heritage buildings; thus, on-site non-invasive techniques have been proposed over time. An innovative active thermographic procedure is proposed and tested in a laboratory to assess the amount of moisture via a non-destructive approach. The methodology is based on heating a brick specimen together with a reference sample which has known thermophysical properties. Evaporation is inhibited by an impermeable film applied to the samples. The trends in the surface temperatures of both materials are recorded using infrared thermography and compared with each other: the calculation of the thermal inertia of the wetted material is retrieved from the comparison of the temperature trends in both samples. The water content value is thus determined from the thermal inertia of the sample.

The presence of moisture in masonry is crucial because it causes and exacerbates various deterioration mechanisms, such as crystallization of salts, mechanical stresses due to freeze-thaw cycles, biological degradation, etc. The assessment of the water content is critical for cultural heritage buildings; thus, on-site non-invasive techniques have been proposed over time. An innovative active thermographic procedure is proposed and tested in a laboratory to assess the amount of moisture via a non-destructive approach. The methodology is based on heating a brick specimen together with a reference sample which has known thermophysical properties. Evaporation is inhibited by an impermeable film applied to the samples. The trends in the surface temperatures of both materials are recorded using infrared thermography and compared with each other: the calculation of the thermal inertia of the wetted material is retrieved from the comparison of the temperature trends in both samples. The water content value is thus determined from the thermal inertia of the sample.

Hydrochemical study of groundwater in the aquifer system of the southeast coastal area of Bangladesh was carried out to investigate the processes of groundwater hydrochemistry as well as the suitability of groundwater for drinking purposes. Water samples from tube wells (depths 6.5–165 m) were collected and examined several water quality parameters to describe the hydrogeochemical characteristic. Most of the water samples were found as fresh and soft water with few numbers of hard and brackish water. The overall sequence of cation and anion throughout the study area are Ca2+> Na+> Mg2+> K+ and HCO3−> CO3−> NO3−> SO42−> Cl− respectively. Maximum water quality parameters satisfy the drinking water quality standard proposed by WHO. Piper diagram suggests that Ca2+- Mg2+- HCO3− (80%) and Ca2+- Na+- HCO3− (20%) facies are the predominant water type. Gibb’s plot implies a rock dominant inheritance that regulates the groundwater chemistry. The most significant hydroche...

Although the study of pipe–soil interaction has more than 80 years of history, a lack of long-term field performance data still exists when it comes to the structural performance of large-diameter, profile–wall thermoplastic pipes under deep soil cover. Field-monitored structural performance data were taken for 1050-mm (42-in.) diameter, corrugated high-density polyethylene (HDPE) pipes, which were subjected to 6.1-m (20-ft) and 12.2-m (40-ft) soil fill heights at the ORITE deep burial test site at the Ohio Research Institute for Transportation and the Environment. The field data accumulated over about 2 years indicate that these HDPE pipes are performing satisfactorily. None of the pipes deflected more than −2.5% vertically and 1% horizontally. Closer examinations of the field data obtained at the end of construction and a few months afterward provided insights into the HDPE pipe performance under deep soil cover. Among the analytical methods evaluated in light of the field data, t...