Taylor\u27s slope stability chart for combined effects of horizontal and vertical seismic coefficients

Design standards and codes of practice on earth slope stability often recommend the pseudo-static method of analysis for determining the factor of safety of a slope subjected to seismic forces. In most pseudo-static methods of analysis, the horizontal seismic force is considered without due weightage to vertical seismic force. In the past, Taylor\u27s stability chart for a homogeneous cohesive-frictional soil slope has been extended to consider the effect of horizontal seismic force only. In this paper, an attempt is made to develop an analytical formulation considering both horizontal and vertical seismic forces in order to estimate the factor of safety of the homogeneous, cohesive-frictional soil slopes with simple profiles using Taylor\u27s stability chart. The analytical formulation is based on the friction circle method, which is one of the methods of static slope stability analysis. Several field cases have been analysed considering slope geometry, soil properties and seismic loading conditions so that Taylor\u27s stability chart can be routinely used by practising engineers considering the effects of both horizontal and vertical seismic forces. An illustrative example is included in order to explain how practising engineers can use the graphical presentations developed in this paper as the design charts for stability analysis. This illustrative example has also been solved using Plaxis 2D, a commercially available finite-element software, as a comparison

The Elements of Supernatural and Magic Realism in Toni Morrison’s Beloved

The present research paper is a study of the elements of Magic Realism and the supernatural elements in the novel, Beloved by the Nobel laureate novelist Toni Morrison. The term Magic Realism was originally applied in the 1920s to the school of surrealist German painters and was later used to describe the process fiction of writers like George Luis Burges, Gabriel Garcia Marquez, and Salman Rushdie etc. These writers weave a sharply etched realism representing ordinary events and details together with fantastic and dream-like elements, as well as with material derived from myth and fairy tales. The German critic Franz Roz introduced the concept of Magic realism in 1920 and it was first used in paintings. The term was introduced in the book Post-expressionism, Magic Realism: Problem of the Most Recent European Paintings in 1925. The purpose here is to analyze the elements of magic realism in the novel, Beloved. We can see supernatural elements in Sethe’s house that bring chaos by haunting everyone through its mysterious presence, and making Sethe’s both the sons Howard and Buglar run away. It appears to be the ghost of a baby which was murdered by Sethe. The ghost causes the things in the house to break and shake mysteriously. In magic realism fiction the ghosts are the central characters generally. In the novel Beloved Morrison has portrayed the ghost as a living person. Thus, the dominance of a unique, mystical and gloomy atmosphere can be seen throughout the novel

Stability analysis and design charts for a sandy soil slope supporting an embedded strip footing

In several field situations, especially in the hilly terrains, the construction of footings on slopes becomes essential. The factor of safety of a slope supporting a loaded footing on the crest is dependent on the position of the footing from the crest edge. Most studies in the past have focused on analysing the bearing capacity and settlement behaviour of a footing resting on a slope crest, but foundations in most infrastructure projects are usually built at some depth below the ground surface. Therefore, the availability of some form of design charts for determining the factor of safety of a slope supporting an embedded footing will be highly useful for the practising engineers. In the current work, the finite element analysis of a sandy soil slope supporting an embedded footing was carried out using the Plaxis 2D, a finite element-based commercial software, in order to examine the effect of slope geometry, soil properties, and footing locations on the stability of slope in terms of factor of safety. The results of the analysis show that the factor of safety of the slope increases with an increase in the footing edge distance, footing depth and soil relative density, but it decreases with an increase in the slope angle and applied pressure on the footing. Some design charts have been developed along with an illustrative example to explain how these charts can be used by the practising engineers

Track-index-guided sustainable off-road operations using visual analytics, image intelligence and optimal delineation of track features

Visual-analytics-guided systems are replacing human efforts today. In many applications, movement in off-road terrain is required. Considering the need to negotiate various soft ground and desertic conditions, the beaten tracks of leading vehicles considered to be safe and suitable for guiding are used in such operations. During night, often, these tracks pass through low-contrast conditions posing difficulty in their identification. The maximization of track contrast is therefore desired. Many contrast enhancement techniques exist but their effectiveness varies as per the surrounding. Other than conventional techniques, the role of texture too becomes important for enhancing the differentiable track contrast. Gray-level co-occurrence matrix (GLCM)-based statistic measures are used here to evaluate the track texture. These measures are seen to improve the contrast of vehicle tracks significantly. A track-index-based technique is proposed to sort various images as per their effectiveness in increasing the track contrast. Different forms of track indices are proposed and compared. The proposed track index is seen as effective in sorting 88.8% of contrast images correctly. The proposed technique of creating and sorting images based on the contrast level is seen as a useful tool for improved fidelity in many difficult situations for making the off-road operations sustainable

Adaptive Technique for Contrast Enhancement of Leading Vehicle Tracks

During movement in various unpaved terrain conditions, the track impressions left over by the leading vehicles provide guiding and safe routes in the area. The delineation of these tracks captured by the images can extend immense support for guidance in real time. These tracks that look like edges in coarse-resolution images take the shape of elongated areas in fine-resolution images. In such a scenario, the high pass and edge detection filters give limited information to delineate these tracks passing through different surroundings. However, the distinct texture of these tracks assists in the delineation of these tracks from their surroundings. Gray level co-occurrence matrix (GLCM) representing the spatial relation of pixels is employed here to define the texture. The authors investigated the influence of different resolutions on the distinguishability of these tracks. The study revealed that texture plays an increasing role in distinguishing objects as the image resolution improves. The texture analysis extended to investigate the track impressions left over by the leading vehicle brings out an ample scope in delineating these tracks. The measures could improve the track contrast even better than conventional techniques. To select the most optimal contrast enhancement measure in a given scenario, authors proposed a quantified measure of track index. An investigation is made on the difference-based track index (TI) representing the mean contrast value of the track vis-à-vis off-track areas. The results show an increase in the quantified contrast from 7.83 per cent to 29.06 per cent. The proposed technique highlights the image with the highest track contrast in a given scenario. The study can lead to onboard decision-making for the rut following vehicles moving in low-contrast terrain

Liquefaction proneness of stratified sand-silt layers based on cyclic triaxial tests

Most studies on liquefaction have addressed homogeneous soil strata using sand or sand with fine content without considering soil stratification. In this study, cyclic triaxial tests were conducted on the stratified sand specimens embedded with the silt layers to investigate the liquefaction failures and void-redistribution at confining stress of 100 kPa under stress-controlled mode. The loosening of underlying sand mass and hindrance to pore-water flow caused localized bulging at the sand-silt interface. It is observed that at a silt thickness of 0.2H (H is the height of the specimen), nearly 187 load cycles were required to attain liquefaction, which was the highest among all the silt thicknesses with a single silt layer. Therefore, 0.2H is assumed as the optimum silt thickness (topt). The silt was placed at the top, middle and bottom of the specimen to understand the effect of silt layer location. Due to the increase in depth of the silt layer from the top position (capped soil state) to the bottom, the cycles to reach liquefaction (Ncyc,L) increased 2.18 times. Also, when the number of silt layers increased from single to triple, there was an increase of about 880% in Ncyc,L. The micro-characterization analysis of the soil specimens indicated silty materials transported in upper sections of the specimen due to the dissipated pore pressure. The main parameters, including thickness (t), location (z), cyclic stress ratio (CSR), number of silt layers (n) and modified relative density (Dr,m), performed significantly in governing the liquefaction resistance. For this, a multilinear regression model is developed based on critical parameters for prediction of Ncyc,L. Furthermore, the developed constitutive model has been validated using the data from the present study and earlier findings

An experimental study on micro-structural and geotechnical characteristics of expansive clay mixed with EPS granules

© 2020 Pavement structures constructed on the expansive soil subgrade experience a higher upward pressure compared to any other subgrade material. The upward pressure is caused due to high swelling and shrinkage characteristics of expansive clay soil. The present study has investigated and identified the mechanisms by which a remolded expansive soil can be modified to reduce the upward pressure and swelling (heave). To achieve this, a lightweight, environmentally friendly, and high pressure resistive expanded polystyrene (EPS) granules have been used with expansive soil s from three different locations of Madhya Pradesh state, India. The study has been performed to understand the swelling and strength characteristics of soil with and without the use of EPS (density = 21.6 kg/m3) as per ASTM specifications. The chemical and microstructural components of the expansive soil were investigated using autotuned total reflectance Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM). Several laboratory experiments, including optimum moisture content, maximum dry unit weight, grain-size distribution, liquid limit, plastic limit, shrinkage limit, free swell index, unconfined compressive strength, and pressure swelling tests were carried out on the statically compacted expansive clay soil specimen with and without EPS (0.25%, 0.50%, 1.00%). The maximum addition of EPS was considered as 1% as the very high expansion was observed, and beyond this, further addition of EPS was not feasible. The results show that the swelling pressure, expansion percentage, and time rate of swell decrease, whereas the unconfined compressive strength (UCS) increases with the addition of EPS. The inclusion of EPS in expansive clay soil exponentially reduced the heave and the upward pressure, whereas the maximum UCS was observed at 0.5%

A CONCEPTUAL STUDY OF MUTRASHMARI; ITS MANAGEMENT WITH NIDANA PARIVARJANA AND PATHYA PALANA

Mutrashmari is one of the commonest diseases of Mutravaha Srotasa. Acharya Sushruta has mentioned Mutrashmari as one of the Ashta Mahagada, because it is not easy to treat and there is need to pay more attention to its cure. In the contemporary medical science it is correlated with Urolithiasis or Urinary Calculi. The incidences of Mutrashmari are increasing at the present era due to various reasons like altered food habits, changed lifestyle, stress, strain, environmental pollutions etc. In Ayurvedic texts these factors have been indicated as Nidana. Nidana plays a major role in the occurrence of disease, due to Nidana Sevana, Doshas get aggravated, along with Dushya they cause Sroto Dushti and then disease manifests. Vata, Pitta and Kapha all three Doshas are involved in the Samprapti of Mutrashmari, therefore understanding the Samprapti is essential for treatment of disease, because disintegration of Samprapti Sanghatan is Chikitsa. Srotasa is an important Samprapti Ghataka in formation of disease. Compatible food to Srotasa is Pathya. Srotasa is guarded by avoiding causative factors of disease and taking compatible food to Srotasa, which prevents the Srtotovarodha and thereby prevent the disease. This article is mainly focused at Nidana-Samprapti Parak study of Mutrashmari and importance of Nidana Parivarjana and Pathya Palana in its treatment

Mapping the Research Publications Pattern of Faculties of Library and Information Science Department, Mizoram University, Aizawl From 2008-2017: A Bibliometric Study

The paper focuses on the mapping of library and information science research publication output of the faculty member of the department of library and information science (DLIS), Mizoram University (MZU) during the period of ten years i.e. (2008-2017). The detailed curriculum vitae of faculty members of DLIS were obtained and bibliographic information of their papers was recorded. The study deals with 279 publications of DLIS, MZU. The present study examines and analysis that the DLIS output by different patterns such as the form of publication, the relative growth rate of publications, doubling time for publications, annual growth rate (AGR) of the publications and compound AGR of publications during the period of study

Numerical modeling of virus transport through unsaturated porous media

This paper describes the movement of virus in one-dimensional unsaturated porous media. The governing virus transport equations consider the inactivation in liquid phase, liquid–solid interface, air–liquid interface, and sorption in both liquid–solid and air–liquid interfaces. Finite-volume method has been used for solving the advection and dispersion processes of the virus transport equation. The effects of transport parameters on virus concentration profiles have been investigated for virus present in liquid phase, adsorbed liquid–solid and liquid–air phases. The results show that the movement of viruses in three phases is affected by soil moisture, inactivation rate, pore velocity, and mass transfer coefficients. It is found that the magnitude of virus sorption is higher at the air–liquid interface as compared to the liquid–solid interface. A higher value of mass transfer coefficient leads to an increase in the virus concentration in both liquid–solid and air–liquid interfaces