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The purpose of this study is to investigate the effect of presence of buried flexible pipe on the bearing capacity of shallow footing. First, a model study is performed where shallow footing model is tested for its load settlement behavior, with and without the existence of buried PVC pipe lying vertically below the base of the footing.

The experimental set-up consisted of a steel box filled with sand at two different relative density values [RD = 50 per cent (medium dense) and RD = 80 per cent (dense sand)] and vertical load was applied on the model footing through hydraulic jack and reaction frame arrangement connected with a proving ring. Test results are verified numerically using commercially available finite element code PLAXIS 2D. With due verification, a parametric study has been conducted, numerically, by varying the range of input parameters, such as unit weight, angle of internal friction, diameter of buried conduit and the Elastic modulus of the soil to assess the pre cent reduction in the capacity of the foundation soil because of the presence of underlying buried flexible pipe.

Results show that for each footing, there exists a critical depth below which the presence of the buried conduit has negligible influence on the footing performance. When the conduit is located above the critical depth, the bearing capacity of the footing varies with various factors, such as geotechnical parameters of soil and location and diameter of the buried conduit.

It is an original paper performed to assess the presence of buried flexible pipe on the bearing capacity of the shallow footing.

The purpose of this work is to study the in-situ performance of ternary geopolymer concrete in road repair work. Geopolymer cement concrete is an attractive alternative to Portland cement concrete owing to environmental, economic and performance benefits. Industrial wastes, such as fly ash (FA) and ground granular blast furnace slag (GGBS), have been extensively used to manufacture unitary and binary geopolymer concrete with heat activation (at different temperature); however, it has indicated a limitation for its application in precast industry only.

In the present study, efforts have been made to produce a ternary geopolymer concrete mix, using GGBS, FA and Silica fumes (SF) in varied proportion mixed with 8 M sodium hydroxide (NaOH) as alkali activator and cured at ambient temperature. Total ten geopolymer concrete mixes have been prepared and tested for strength and durability properties and compared with control mix of ordinary Portland cement (OPC). Based on the mechanical properties of various mixes, an optimum geopolymer concrete mix has been identified. The control mix and optimum geopolymer have been studied for microstructural properties through scanning electron microscopy.

The in situ performance of the optimum mix has been assessed when used as a road repair material on a stretch of road. The ternary geopolymer concrete mixes (a) 65% GGBS + 25% FA + 10% SF, (b) 70% GGBS + 20% FA + 10% SF, and (c) 75% GGBS + 15% FA + 10% SF have resulted in good strength at ambient temperature and the mix 75% GGBS + 15% FA + 10% SF have shown good in situ performance when tested for road repair work.

Geopolymer concrete is gaining interest in many fields as an alternative to conventional concrete, as it not only reduces carbon footprint due to huge cement production but also provides a sustainable disposal method for many industrial wastes. This paper focuses on finding some alternative of OPC concrete to reduce dependency on the OPC.

This paper aims to study the effect of the addition of water treatment plant sludge (WTPS) and processed tea waste (PTW) on the properties of burnt clay bricks. The reuse of WTP sludge as a raw material for brick production is a long-term approach, to sludge disposal, for economic and environmental sustainability. Sludge have been added at 10, 20, 30 and 40% and processed tea waste at 5% (by weight) in replacement of clay for brick manufacturing. Each batch of hand-moulded bricks was fired in a heat controlled furnace at a temperature of 990°C. The compressive strength has been found to increase with the sludge content, however, a slight decrease in compressive strength was observed with tea waste addition. Further, PTW addition has improved the thermal insulation of bricks as compared to controlled bricks. The study shows that 40% WTPS, 5% PTW and 55% natural clayey soil can be considered as an optimum mix for bricks with good compressive strength as well as improved thermal insulation property.

Four different mixing ratios of sludge at 10, 20, 30 and 40% of the total weight of sludge-clay mixtures were used to make bricks. Similarly, PTW was investigated as a substitute of natural clayey soil in brick manufacturing. Each batch of hand-moulded bricks was fired in a heat controlled furnace at a temperature of 990°C. The physical, mechanical and engineering properties of the produced WTPS bricks and PTW bricks were determined and evaluated according to various Indian Standard Codes of Specification for burnt clay bricks and certain reference books.

The results exhibited that WTP sludge and PTW can be used to produce good quality brick for various engineering applications in construction and building. Increasing the sludge content increases the compressive strength. Moreover, thermal insulation of PTW bricks depicted an upward trend when compared to controlled bricks. Hence, an optimum mixture of 40% WTPS, 5% PTW and 55% natural clayey soil was found, at which bricks showed good compressive strength as well as improved thermal insulation property of the building material.

The present work provides a sustainable solution for disposal of WTP sludge and tea waste. Utilization of these waste materials in brick manufacturing is viable and economic solution.

Bricks with 40% WTP sludge and 5% processed tea waste proved to be economic, technically sound for construction purposes with added thermal insulation properties.

Bulk amount of waste such as WTP sludge is a threat to society owing to its environmental implications of disposal. Authors propose to use WTP sludge and tea waste for brick manufacturing and provide a solution to its disposal.

Water treatment plant sludge along with tea waste have not been tried for brick manufacturing so far. Hence, the composition is new in itself and also have resulted into good performance.

The present study aims to demonstrate the performance assessment of flexible pavement structure in probabilistic framework with due consideration of spatial variability modeling of input parameter.

The analysis incorporates mechanistic–empirical approach in which numerical analysis with spatial variability modeling of input parameters, Monte Carlo simulations (MCS) and First Order Reliability Method (FORM) are combined together for the reliability analysis of the flexible pavement. Random field concept along with Cholesky decomposition technique is used for the spatial variability modeling of the input parameter and implemented in commercially available finite difference code FLAC for the numerical analysis of pavement structure.

Results of the reliability analysis, with spatial variability modeling of input parameter, are compared with the corresponding results obtained without considering spatial variability of parameters. Analyzing a particular three-layered flexible pavement structure, it is demonstrated that spatial variability modeling of input parameter provides more realistic treatment to property variations in space and influences the response of the pavement structure, as well as its performance assessment.

Research is based on reliability analysis approach, which can also be used in decision-making for quality control and flexible pavement design in a given environment of uncertainty and extent of spatially varying input parameters in a space.

The purpose of this paper is to investigate the first three stochastic natural frequencies of skewed sandwich plates, considering uncertain system parameters. To conduct the sensitivity analysis for checking the criticality of input parameters.

The theoretical formulation is developed based on higher-order-zigzag theory in accordance with the radial basis function (RBF) and stochastic finite element (FE) model. A cubic function is considered for in-plane displacement over thickness while a quadratic function is considered for transverse displacement within the core and remains constant in the facesheet. RBF is used as a surrogate model to achieve computational efficiency and accuracy. In the present study, the individual and combined effect of ply-orientation angle, skew angle, number of lamina, core thickness and material properties are considered for natural frequency analysis of sandwich plates.

Results presented in this paper illustrates that the skewness in the sandwich plate significantly affects the global dynamic behaviour of the structure. RBF surrogate model coupled with stochastic FE approach significantly reduced the computational time (more than 1/18 times) compared to direct Monte Carlo simulation approach.

The stochastic results for dynamic stability of sandwich plates show that the inevitable source uncertainties present in the input parameters result in significant variation from the deterministic value demonstrates the need for inclusive design paradigm considering stochastic effects. The present paper comprehensively establishes a generalized new RBF-based FE approach for efficient stochastic analysis, which can be applicable to other complex structures too.