Showing papers in "Journal of The Institution of Engineers : Series A in 2017"

Spatial Interpolation of Reference Evapotranspiration in India: Comparison of IDW and Kriging Methods

Abstract: In the present study, to understand the spatial distribution characteristics of the ETo over India, spatial interpolation was performed on the means of 32 years (1971–2002) monthly data of 131 India Meteorological Department stations uniformly distributed over the country by two methods, namely, inverse distance weighted (IDW) interpolation and kriging. Kriging was found to be better while developing the monthly surfaces during cross-validation. However, in station-wise validation, IDW performed better than kriging in almost all the cases, hence is recommended for spatial interpolation of ETo and its governing meteorological parameters. This study also checked if direct kriging of FAO-56 Penman–Monteith (PM) (Allen et al. in Crop evapotranspiration—guidelines for computing crop water requirements, Irrigation and drainage paper 56, Food and Agriculture Organization of the United Nations (FAO), Rome, 1998) point ETo produced comparable results against ETo estimated with individually kriged weather parameters (indirect kriging). Indirect kriging performed marginally well compared to direct kriging. Point ETo values were extended to areal ETo values by IDW and FAO-56 PM mean ETo maps for India were developed to obtain sufficiently accurate ETo estimates at unknown locations.

Performance of Microbial Concrete Developed Using Bacillus Subtilus JC3

Abstract: Concrete is vulnerable to deterioration, corrosion, and cracks, and the consequent damage and loss of strength requires immensely expensive remediation and repair. So need for special concrete that they would respond to crack formation with an autonomous self-healing action lead to research and development of microbial concrete. The microbial concrete works on the principle of calcite mineral precipitation by a specific group of alkali-resistant spore-forming bacteria related to the genus Bacillus called Bacillus subtilis JC3, this phenomenon is called biomineralization or Microbiologically Induced Calcite Crystal Precipitation. Bacillus subtilis JC3, a common soil bacterium, has inherent ability to precipitate calcite crystals continuously which enhances the strength and durability performance of concrete enormously. This microbial concrete can be called as a “Self healing Bacterial Concrete” because it can remediate its cracks by itself without any human intervention and would make the concrete more durable and sustainable. This paper discuss the incorporation of microorganism Bacillus subtilis JC3 (developed at JNTU, India) into concrete and presents the results of experimental investigations carried out to study the improved durability and sustainability characteristics of microbial concrete.

Mass Housing Using GFRG Panels: A Sustainable, Rapid and Affordable Solution

Abstract: This work gives an overview of research and development carried out at IIT Madras, using glass fibre reinforced gypsum (GFRG) panels, to provide an innovative solution for rapid and affordable mass housing. The GFRG panels (124 mm thick), made from recycled industrial waste gypsum (from the fertilizer industry), are prefabricated in 3 m × 12 m sizes with cellular cavities inside, which can be filled with reinforced concrete wherever required and can be used as walls as well as floor slabs. The tests carried out (over the past 12 years) establish the performance of GFRG building systems to resist gravity and lateral loads as a load-bearing system (without beams and columns) in multi-storeyed buildings up to 8–10 storeys, with adequate strength, serviceability, durability and ductility. A two-storeyed four-apartment demonstration building has also been successfully constructed in the IIT Madras campus and presently a mass housing scheme (40 apartment units) using this technology is being demonstrated at Nellore. A structural design code has also been approved by the Bureau of Indian Standards, based on the extensive studies carried out on GFRG building systems.

An Overview of Key Indicators and Evaluation Tools for Assessing Housing Quality: A Literature Review

Abstract: The issue of the housing quality has been addressed for various stakeholders at different levels. There exist varied opinion about its measurability and possible applications. Thus the study is carried out to have an insight into the concept of housing quality and its relevance in the changing demographics, technological, socio-economic and socio-cultural conditions. This study attempts to summarize the literature that addresses past research concerned with factors related to housing quality, its measurement methodology and critically examines the broad key indicators identified to have impact upon enhancing the housing quality. This work discusses the recent techniques which are extensively used for analysis of housing quality.

Design Optimization of Reinforced Concrete Beams

Abstract: This work presents a typical optimization technique i.e. Particle Swarm Optimization (PSO) to achieve optimal design of Reinforced Concrete (RC) beams. Optimal cross-sectional sizing of an RC beam results in cost saving, but it (optimal sizing) cannot be standardized for the various factors that influence a given design. An algorithm has been developed to search for a minimum cost solution that satisfies Indian codal requirements for RC beams. The objective function consists of the cost of concrete and rebars as prevalent at the place of construction. Successful implementation of the algorithm clearly establishes PSO’s ability of performance in the case of RC beams. A number of examples have been presented to show the effectiveness of this formulation for achieving optimal design.

Uplift Capacity of Inclined Underreamed Piles Subjected to Vertical Load

Abstract: Many offshore structures are subjected to overturning moments due to wind load, wave pressure, and ship impacts. Inclined (batter) piles are used to support such structures, and to carry the horizontal and vertical loads resulted from the overturning moments. Though studies have been done with inclined piles having no underream bulb, little information is available in the literature about estimating the uplift capacity of inclined underreamed piles. In the present study laboratory experiments have been done with vertically loaded model piles having no underream as well as with one and two underreams. The piles were positioned at angle of inclination of θ = 0°, 10°, 20°, 30° (with vertical); and placed in locally available sand under vertical uplift load. Three different pile stem diameters (D = 20, 25, and 35 mm) were used. The corresponding pile length to stem diameter (l/D) ratio were 18, 14, and 10 respectively. Experiments had been conducted with two relative different densities (45 and 70%) of sand. The failure uplift loads were obtained in each case. It had been found that for inclined piles increase in number of underream bulbs from 0 to 2 was quite effective in resisting uplift loads corresponding to piles having l/D equals to 10. The percentage decreases in uplift capacity corresponding to increase in inclination angle were more pronounced for piles with double underreams.

Green Synthesis of Silver Nanoparticles by using Eucalyptus Globulus Leaf Extract

Abstract: A single step eco-friendly, energy efficient and economically scalable green method was employed to synthesize silver nanoparticles. In this work, the synthesis of silver nanoparticles using Eucalyptus globulus leaf extract as reducing and capping agent along with water as solvent at normal room temperature is described. Silver nanoparticles were prepared from aqueous silver nitrate solution by adding the leaf extract. The prepared nanoparticles were characterized by using UV–visible Spectrophotometer, X-ray diffractometer, High Resolution Transmission Electron Microscope (HR-TEM) and Fourier Transform Infrared Spectroscope (FTIS). X-ray diffraction studies brought to light the crystalline nature and the face centered cubic structure of the silver nanoparticles. Using HR-TEM. the nano sizes and morphology of the particles were studied. The mean sizes of the prepared silver nanoparticles ranged from 30 to 36 nm. The density of the particles was tuned by varying the molar ratio of silver nitrate. FTIS studies showed the functional group of organic molecules which were located on the surface of the silver nanoparticles. Originating from the leaf extracts, these organic molecules reduced and capped the particles.

Landfill Site Selection by AHP Based Multi-criteria Decision Making Tool: A Case Study in Kolkata, India

Abstract: This work presents a Multi-criteria Decision Making (MCDM) tool to select a landfill site from three candidate sites proposed for Kolkata Municipal Corporation (KMC) area that complies with accessibility, receptor, environment, public acceptability, geological and economic criteria. Analytical Hierarchy Process has been used to solve the MCDM problem. Suitability of the three sites (viz. Natagachi, Gangajoara and Kharamba) as landfills as proposed by KMC has been checked by Landfill Site Sensitivity Index (LSSI) as well as Economic Viability Index (EVI). Land area availability for disposing huge quantity of Municipal Solid Waste for the design period has been checked. Analysis of the studied sites show that they are moderately suitable for landfill facility construction as both LSSI and EVI scores lay between 300 and 750. The proposed approach represents an effective MCDM tool for siting sanitary landfill in growing metropolitan cities of developing countries like India.

Wave Reflection and Loss Characteristics of an Emerged Quarter Circle Breakwater with Varying Seaside Perforations

Abstract: Breakwaters are one of the most important harbour structures constructed to withstand and dissipate the dynamic energy due to the action of the waves Due to fast growing need of the universe and advances in technology different types of breakwaters are being developed Quarter circle breakwater is a new type of breakwater emerged from semi circular breakwater and the first model was developed in Peoples Republic of China (2006) Quarter circle breakwater with perforations posses merits of caisson as well as perforated breakwaters such as low weight, requires less materials, suited for poor soil conditions, easily transported, handled and placed at the site, aesthetically pleasing, cost effective, eco-friendly and stable Therefore it is necessary to carry out detailed studies on hydrodynamic characteristics to investigate the suitability and applicability of various types of quarter circle breakwaters The present study investigates the wave reflection and loss characteristics of an emerged seaside perforated quarter circle breakwater of radius 55 cm and with varying ratios of spacing to diameter of perforations, for different water depths and wave conditions The tests were conducted in the two-dimensional monochromatic wave flume available in Marine Structures laboratory of Department of Applied Mechanics and Hydraulics of National Institute of Technology, Surathkal, Karnataka, India The results were plotted as non-dimensional graphs and it was observed that the reflection coefficient increases with increase in wave steepness for all values of ratio of height of breakwater structure to water depth For a constant water depth, wave reflection increases with increase in ratio of spacing to diameter of perforations It was also found that the loss coefficient decreases with increase in wave steepness for all values of ratio of height of breakwater structure to water depth, and ratio of spacing to diameter of perforations

The Influence of Various Process Parameters on Dissolution Kinetics and Mechanism of Struvite Seed Crystals

Abstract: The basic understanding of struvite dissolution chemistry is essential to designers and operators for anticipating struvite problem and remediating existing struvite damage in a wastewater treatment. The dissolution kinetic of struvite seed crystals is very important parameters to determine a solid substance entering in solvent to yield a solution. In this study the dissolution kinetics of struvite crystals (MgNH4PO4·6H2O) in deionized water was investigated in a batch crystallizer. The effects of stirrer speeds, temperature and seed crystals size on the dissolution rate were determined. The results showed that an increase of struvite dissolution rate with increasing stirring speed. Struvite dissolution occurred via a diffusion-controlled mechanism in the range of stirrer speeds 120–400 rpm but became interfacial-reaction-controlling at over 400 rpm. The influence of temperature on dissolution kinetic of struvite crystals was also investigated at stirrer speeds of 200 and 500 rpm. The dissolution rates increased with an increase in the temperature for both stirrer speeds. The change in activation energies at different stirrer speeds confirmed that the change of dissolution mechanism from a diffusion-controlled mechanism at low stirrer speeds to an interfacial-reaction-controlled mechanism at higher stirrer speeds. The dissolution rate of struvite crystals increased with smaller crystal sizes.

Road Traffic Noise Exposure and Hearing Impairment Among Traffic Policemen in Surat, Western India

Abstract: Among all of the sources responsible for noise pollution, traffic related sources are of great environmental concern and increasing level of discomfort in urban areas with increasing traffic concentration. It will be a larger and serious problem in the future, if effective precautions are not taken addressed and attended to. Hence, a study was undertaken to measure the levels of road traffic noise at major intersections of Surat city, located in Western India and assess the hearing impairment among the exposed group of population i.e. the traffic policemen. Manual noise measurements and vehicle counts were performed at three of the busiest traffic intersections in the city for a period of 12 h. Audiometric screening was done on 46 policemen working at these intersections to determine the occurrence of hearing impairment. At all the three intersections, Leq measured was well above the permissible levels of 65 dBA for daytime. The Lmax recorded for three intersections were 84.6 dBA (07:36 pm), 87.3 dBA (06:32 pm) and 85.6 dBA (11:41 am). Audiometric screening showed that only 10 policemen (22%) had normal hearing. Slight, moderate and severe hearing impairment was recorded among 13 (28%), 18 (39%) and 5 (11%) policemen respectively. Of the total 46 policemen, none had profound impairment (deafness, hearing loss >81 dB). Of the 36 policemen having hearing impairment, 27 had bilateral impairment.

Artificial Intelligence Techniques for Predicting and Mapping Daily Pan Evaporation

Abstract: In this study, Artificial Intelligence techniques such as Artificial Neural Network (ANN), Model Tree (MT) and Genetic Programming (GP) are used to develop daily pan evaporation time-series (TS) prediction and cause-effect (CE) mapping models. Ten years of observed daily meteorological data such as maximum temperature, minimum temperature, relative humidity, sunshine hours, dew point temperature and pan evaporation are used for developing the models. For each technique, several models are developed by changing the number of inputs and other model parameters. The performance of each model is evaluated using standard statistical measures such as Mean Square Error, Mean Absolute Error, Normalized Mean Square Error and correlation coefficient (R). The results showed that daily TS-GP (4) model predicted better with a correlation coefficient of 0.959 than other TS models. Among various CE models, CE-ANN (6-10-1) resulted better than MT and GP models with a correlation coefficient of 0.881. Because of the complex non-linear inter-relationship among various meteorological variables, CE mapping models could not achieve the performance of TS models. From this study, it was found that GP performs better for recognizing single pattern (time series modelling), whereas ANN is better for modelling multiple patterns (cause-effect modelling) in the data.

Effect of Response Reduction Factor on Peak Floor Acceleration Demand in Mid-Rise RC Buildings

Abstract: Estimation of Peak Floor Acceleration (PFA) demand along the height of a building is crucial for the seismic safety of nonstructural components. The effect of the level of inelasticity, controlled by the response reduction factor (strength ratio), is studied using incremental dynamic analysis. A total of 1120 nonlinear dynamic analyses, using a suite of 30 recorded ground motion time histories, are performed on mid-rise reinforced-concrete (RC) moment-resisting frame buildings covering a wide range in terms of their periods of vibration. The obtained PFA demands are compared with some of the major national seismic design and retrofit codes (IS 1893 draft version, ASCE 41, EN 1998, and NZS 1170.4). It is observed that the PFA demand at the building’s roof level decreases with increasing period of vibration as well as with strength ratio. However, current seismic building codes do not account for these effects thereby producing very conservative estimates of PFA demands. Based on the identified parameters affecting the PFA demand, a model to obtain the PFA distribution along the height of a building is proposed. The proposed model is validated with spectrum-compatible time history analyses of the considered buildings with different strength ratios.

Life Cycle Energy Assessment of a Multi-storey Residential Building

Abstract: This study presents the findings of life cycle energy assessment of two multi-storey residential buildings. These buildings consist of a total of 60 homes. The usable floor area is 43.14 m2 (463.36 ft2) per home. A detailed estimation of embodied energy is carried out by considering the use of materials during building construction. Major contributors of embodied energy are found to be steel, cement and aluminum. Monthly building operation energy was assessed using a total of 2520 data samples corresponding to 3 years of building operation. Analysis of a base case scenario, with 50 years of service life and average monthly operation energy, indicates that the embodied energy and the operation energy account for 16 and 84% of the life cycle energy respectively. Sensitivity analysis is carried out to study the influence of service life and operation energy on the relative contribution of embodied energy and operation energy. It is found that the embodied energy represents as high as 31% of the life cycle energy depending upon the variation in the operation energy and the service life. Hence, strategies towards sustainable building construction should also focus on reducing the embodied energy in the design and construction phases in addition to operation energy.

Development and Testing of an ANN Model for Estimation of Runoff from a Snow Covered Catchment

Abstract: In this study, an attempt has been made to develop an ANN model to estimate runoff from a snow covered catchment of eastern Himalaya using feed-forward back-propagation algorithm with Levenberg–Marquardt optimization technique. The ANN model was programmed in C++ whereas a user-friendly GUI was developed in VB. The effects of past days rainfall and present day temperature data was observed on the performance of the selected ANN architecture in modelling snowmelt and monsoon season runoff. For this purpose, 8 years’ (2003–2010) daily data (rainfall, temperature, and discharge) were collected from CWC which were again divided into two parts (2003–2008 and 2009–2010) for training and testing of the ANN model, respectively. Initially it was found that the network can produce acceptable results with only rainfall data as input, but it needs at least past 3 days rainfall data to account for the antecedent moisture condition of the catchment. Networks 4-16-16-1 (with past 3 days rainfall) and 6-18-18-18-1 (with past 5 days rainfall) resulted modelling efficiency of 79.38 and 82.06% in training and 55.13 and 61.06% in validation, respectively. However, addition of present day temperature data as another input improved the performance in both training (ME 83.10 and 82.22%) and testing (ME 62.64 and 61.89%) marginally.

Surface Heave Behaviour of Coir Geotextile Reinforced Sand Beds

Abstract: Soil reinforcement by natural fibers is one of the cheapest and attractive ground improvement techniques. Coir is the most abundant natural fiber available in India and due to its high lignin content; it has a larger life span than other natural fibers. It is widely used in India for erosion control purposes, but its use as a reinforcement material is rather limited. This study focuses on the use of coir geotextile as a reinforcement material to reduce surface heave phenomena occurring in shallow foundations. This paper presents the results of laboratory model tests carried out on square footings supported on coir geotextile reinforced sand beds. The influence of various parameters such as depth of reinforcement, length, and number of layers of reinforcement was studied. It was observed that surface heave is considerably reduced with the provision of geotextile. Heave reduction up to 98.7% can be obtained by the proposed method. Heave reduction is quantified by a non-dimensional parameter called heave reduction factor.

Accelerated In-vessel Composting for Household Waste

Abstract: Composting at household level will serve as a viable solution in managing and treating the waste efficiently. The aim of study was to design and study household composting reactors which would treat the waste at source itself. Keeping this aim in mind, two complete mix type aerobic reactors were fabricated. A comparative study between manually operated and mechanically operated reactor was conducted which is the value addition aspect of present study as it gives an effective option of treatment saving the time and manpower. Reactors were loaded with raw vegetable waste and cooked food waste i.e. kitchen waste for a period of 30 days after which mulch was allowed to mature for 10 days. Mulch was analyzed for its C/N ratio, nitrate, phosphorous, potassium and other parameters to determine compost quality, every week during its period of operation. The results showed that compost obtained from both the reactors satisfied almost all compost quality criteria as per CPHEEO manual on municipal solid waste management and thus can be used as soil amendment to increase the fertility of soil.In terms of knowledge contribution, this study puts forth an effective way of decentralized treatment.

Biodegradation of Methylene Blue Dye by Sequential Treatment Using Anaerobic Hybrid Reactor and Submerged Aerobic Fixed Film Bioreactor

Abstract: Laboratory scale experiments were carried out to access the feasibility of sequential anaerobic/aerobic biological treatment for the biodegradation of Methylene Blue (MB) dye. Anaerobic studies were performed using anaerobic hybrid reactor (consisting of UASB and Anaerobic filter) whereas submerged aerobic fixed film reactor was used as aerobic reactor. Degradation of MB dye was attempted using neutralized acetic acid (1000 mg/L) as co-substrate. MB dye concentration was stepwise increased from 10 to 70 mg/L after reaching steady state in each dye concentration. Such a gradual increase in the dye concentration helps in the proper acclimatization of the sludge to dyes thereby avoiding the possible inhibitory effects to biological activities at high dye concentrations. The overall treatment efficiency of MB through sequential anaerobic–aerobic reactor operation was 90% at maximum attempted dye concentration of 70 mg/L. The effluent from anaerobic reactor was analysed for intermediate biodegradation products through HPLC. It was observed that catechol, quinone, amino pyrine, 1,4 diamino benzene were present. However they were absent in final effluent.

A Comparative Study on Bearing Capacity of Shallow Foundations in Sand from N and ϕ

Abstract: This work presents a comparative study on the bearing capacity of strip, square, circular footings and raft foundations in sand, estimated from the standard penetration resistance, N, and the angle of shearing resistance, ϕ. The net safe bearing capacity estimated directly from N using Teng’s equation is compared with that obtained from ϕ as per IS:6403. Likewise, the net safe settlement pressure determined from IS:8009 (Part 1), based on N, is compared with that attained from the semi-empirical approach of Schmertmann et al. A parametric study quantifies the effects of the standard penetration resistance and the size and depth of foundation on the net safe bearing capacity and the net safe settlement pressure of strip, square, circular footings and raft foundations in sand. Interactive charts are prepared in terms of the standard penetration resistance to highlight the appropriate method for the benefit of civil engineers.

Laboratory Evaluation of the Effects of 3-Chloride Compounds on the Geotechnical Properties of an Expansive Subgrade Soil

Abstract: Expansive soils are known to be problematic due to their nature and behavior. These soils show volume changes due to changes in moisture content, which cause distortions to structures constructed on them. Relentless efforts are being made all over the world to find solution to the problems of expansive soils. In the case of flexible pavements, unless the subgrade is appropriately treated during the construction stage, the maintenance cost will increase substantially due to deterioration. There are many methods of stabilising expansive subgrade soils. Chemical stabilisation is one such technique employed in improving the engineering properties of the expansive soil. Investigations on chemical stabilization of expansive soils revealed that conventionally used lime could be replaced by the chloride compound chemicals because of their ready dissolvability in water, ease of mixing with soil and supply of sufficient cations for ready cation exchange. The main objective of this work is to study the effectiveness of three chloride compound chemicals, ammonium chloride (NH4Cl), magnesium chloride (MgCl2) and aluminum chloride (AlCl3) on the geotechnical properties of an expansive soil. The chemicals content up to 2% were added to the soil and its effect on the index limits, swell pressure, compaction characteristics as well as California bearing ratio are studied. It was observed that aluminum chloride chemical content has a significantly higher influence than the other two chemicals and it could be recognized as an effective chemical stabilizer.

Experimental Investigations on Axially and Eccentrically Loaded Masonry Walls

Abstract: In India, un-reinforced masonry walls are often used as main structural components in load bearing structures. Indian code on masonry accounts the reduction in strength of walls by using stress reduction factors in its design philosophy. This code was introduced in 1987 and reaffirmed in 1995. The present study investigates the use of these factors for south Indian masonry. Also, with the gaining popularity in block work construction, the aim of this study was to find out the suitability of these factors given in the Indian code to block work masonry. Normally, the load carrying capacity of masonry walls can be assessed in three ways, namely, (1) tests on masonry constituents, (2) tests on masonry prisms and (3) tests on full-scale wall specimens. Tests on bricks/blocks, cement-sand mortar, brick/block masonry prisms and 14 full-scale brick/block masonry walls formed the experimental investigation. The behavior of the walls was investigated under varying slenderness and eccentricity ratios. Hollow concrete blocks normally used as in-fill masonry can be considered as load bearing elements as its load carrying capacity was found to be high when compared to conventional brick masonry. Higher slenderness and eccentricity ratios drastically reduced the strength capacity of south Indian brick masonry walls. The reduction in strength due to slenderness and eccentricity is presented in the form of stress reduction factors in the Indian code. These factors obtained through experiments on eccentrically loaded brick masonry walls was lower while that of brick/block masonry under axial loads was higher than the values indicated in the Indian code. Also the reduction in strength is different for brick and block work masonry thus indicating the need for separate stress reduction factors for these two masonry materials.

Combined Performance of Polypropylene Fibre and Weld Slag in High Performance Concrete

Abstract: The effect of polypropylene fibre and weld slag on the mechanical properties of High Performance Concrete (HPC) containing silica fume as the mineral admixtures was experimentally verified in this study. Sixteen series of HPC mixtures(70 MPa) were designed with varying fibre fractions and Weld Slag (WS). Fibre added at different proportion (0, 0.1, 0.3 and 0.6%) to the weight of cement. Weld slag was substituted to the fine aggregate (0, 10, 20 and 30%) at volume. The addition of fibre decreases the slump at 5, 9 and 14%, whereas the substitution of weld slag decreases by about 3, 11 and 21% with respect to the control mixture. Mechanical properties like compressive strength, split tensile strength, flexural strength, Ultrasonic Pulse Velocity test (UPV) and bond strength were tested. Durability studies such as Water absorption and Sorptivity test were conducted to check the absorption of water in HPC. Weld slag of 10% and fibre dosage of 0.3% in HPC, attains the maximum strength and hence this combination is most favourable for the structural applications.

Urban Infrastructure Development Works in India: Delay and Difficulties in Implementation with Reference to a Water Supply Project

Abstract: A handsome project is undertaken by the Govt. of India with funding under either foreign investments or from their own resources. Though the projects are targeted to be implemented within a certain time frame these are never achieved because of the frequent delay in implementation. This has caused time and cost overruns as well as delay in delivering the benefits to the commuters. An insight into the critical problems and affairs by the experts who are engaged in the process of execution/implementation through various consultants has brought to light some key recurring issues with remedial measures requiring action from the different stakeholders for such projects.

Evaluation of Durability Parameters of Concrete with Manufacture Sand and River Sand

Abstract: Most of the states in our country have banned sand quarrying from the river beds, causing a scarcity of natural river sand for the construction sector. Manufacture sand (M-sand) is one of the alternate solutions to replace the river sand (R-sand) in concrete. The main aim of the present study is to evaluate the durability parameters of concrete with M-sand when compared to that of concrete with R-sand. Corrosion of reinforcement is one of the main deteriorating mechanisms of reinforced concrete due to the ingress of chloride ions or carbon-di-oxide. For comparative evaluation of durability parameters, accelerated tests such as Rapid Chloride Permeability Test, Rapid Chloride Migration Test and accelerated carbonation test were carried out on specimens of R-sand and M-sand. All tests were carried out after 90 days of casting. Test results reveal that the durability parameters of the concrete with M-sand in chloride induced environment is relatively better than that of concrete with R-sand and hence is recommended to use M-sand as a replacement to R-sand.

Drift Reliability Assessment of a Four Storey Frame Residential Building Under Seismic Loading Considering Multiple Factors

Abstract: The lateral displacement of Reinforced Concrete (RC) frame building during an earthquake has an important impact on the structural stability and integrity. However, seismic analysis and design of RC building needs more concern due to its complex behavior as the performance of the structure links to the features of the system having many influencing parameters and other inherent uncertainties. The reliability approach takes into account the factors and uncertainty in design influencing the performance or response of the structure in which the safety level or the probability of failure could be ascertained. This present study, aims to assess the reliability of seismic performance of a four storey residential RC building seismically located in Zone-V as per the code provisions given in the Indian Standards IS: 1893-2002. The reliability assessment performed by deriving an explicit expression for maximum roof-lateral displacement as a failure function by regression method. A total of 319, four storey RC buildings were analyzed by linear static method using SAP2000. However, the change in the lateral-roof displacement with the variation of the parameters (column dimension, beam dimension, grade of concrete, floor height and total weight of the structure) was observed. A generalized relation established by regression method which could be used to estimate the expected lateral displacement owing to those selected parameters. A comparison made between the displacements obtained from analysis with that of the equation so formed. However, it shows that the proposed relation could be used directly to determine the expected maximum lateral displacement. The data obtained from the statistical computations was then used to obtain the probability of failure and the reliability.

A Conceptual Approach for Optimising Bus Stop Spacing

Abstract: An efficient public transportation system is essential of any country. The growth, development and shape of the urban areas are mainly due to availability of good transportation (Shah et al. in Inst Town Plan India J 5(3):50–59, 1). In developing countries, like India, travel by local bus in a city is very common. The accidents, congestion, pollution and appropriate location of bus stops are the major problems arising in metropolitan cities. Among all the metropolitan cities in India, Delhi has highest percentage of growth of population and vehicles. Therefore, it is important to adopt efficient and effective ways to improve mobility in different metropolitan cities in order to overcome the problem and to reduce the number of private vehicles on the road. The primary objective of this paper is to present a methodology for developing a model for optimum bus stop spacing (OBSS). It describes the evaluation of existing urban bus route, data collection, development of model for optimizing urban bus route and application of model. In this work, the bus passenger generalized cost method is used to optimize the spacing between bus stops. For the development of model, a computer program is required to be written. The applicability of the model has been evaluated by taking the data of urban bus route of Delhi Transport Corporation (DTC) in Excel sheet in first phase. Later on, it is proposed to develop a programming in C++ language. The developed model is expected to be useful to transport planner for rational design of the spacing of bus stops to save travel time and to generalize operating cost. After analysis it is found that spacing between the bus stop comes out to be between 250 and 500 m. The Proposed Spacing of bus stops is done considering the points that they don’t come nearer to metro/rail station, entry or exit of flyover and near traffic signal.

Vermicomposting of Paper Mill Sludge with Eisenia fetida for its Conversion to Nutrient Using Different Seed Materials

Abstract: In this study, it was aimed for effective utilization of paper mill sludge through vermicomposting by varying seed proportion with sp. Eisenia fetida. Nine plastic trays were used for the experimental work including control. Different seed proportions of cow dung and cattle dung were tested. The multiplication of earthworms in terms of number was counted at the end of vermicomposting. The N, K, Ca, Na values of the manure in each vermibin were estimated before and after vermicomposting. In this study, it was concluded that tray A2 which has combination of 75% Cow dung (CD) and 25% Paper Mill Sludge (PMS) provided better nitrogen synthesis and lowering C/N ratio, whereas tray A4 (25%CD + 75% PMS) yielded better Calcium recovery. Both the seed materials were found to be suitable for Potassium recovery. From this study, it was inferred that vermicomposting of paper mill sludge with sp. Eisenia fetida along with seed materials can also solve the problem of disposal of this sludge.

Influence of Distributed Dead Loads on Vehicle Position for Maximum Moment in Simply Supported Bridges

Abstract: Usually, the design moments in the simply supported bridges are obtained as the sum of moments due to dead loads and live load where the live load moments are calculated using the rolling load concept neglecting the effect of dead loads. For the simply supported bridges, uniformly distributed dead load produces maximum moment at mid-span while the absolute maximum bending moment due to multi-axel vehicles occur under a wheel which usually do not lie at mid-span. Since, the location of absolute maximum bending moment due to multi-axel vehicle do not coincide with the location of maximum moment due to dead loads occurring at mid-span, the design moment may not be obtained by simply superimposing the effect of dead load and live load. Moreover, in case of Class-A and Class-70R wheeled vehicular live loads, which consists of several axels, the number of axels to be considered over the bridge of given span and their location is tedious to find out and needs several trials. The aim of the present study is to find the number of wheels for Class-A and Class-70R wheeled vehicles and their precise location to produce absolute maximum moment in the bridge considering the effect of dead loads and impact factor. Finally, in order to enable the designers, the design moments due to Class-70R wheeled and Class-A loading have been presented in tabular form for the spans from 10 to 50 m.

Time Period Estimation of RC Frame Buildings Through Soil Stiffness Modeling

Abstract: Interaction between a structure and its supporting soil, if it is soft, is of great importance in the design of safer structures and its foundations subjected to earthquake motions. Generally, the structures are analysed considering the foundation ground as stiff and the structures experiencing free field motion. The stiffness modeling of stiff, medium and soft or flexible soil types has been done based on shear wave velocities. In this work, base shear and displacement of a multi-storeyed building on flexible soil considering the effects of soil stiffness are presented in terms of its time period. RC framed buildings with different fundamental time periods and with different foundation soil stiffnesses have been analysed to get a relationship between the time periods. It is expected that the relations presented between time periods and responses would be helpful in design of buildings on soft soil.

Speed Distribution on Two-Lane Rural Highways with Mixed Traffic: A Case Study in North East India

Abstract: This work focuses on minimising inaccuracies in distributional assumptions of speed data on two-lane roads with heterogeneous traffic to improve accuracy in capacity and level of service analysis. Accordingly, field study was conducted on a two-lane highway in India that exhibits heterogeneity in its traffic composition. Two distribution functions, namely, normal and logistic were examined for the observed speed data. The appropriate function was chosen using a methodology based on K–S test and field validation. Logistic distribution function was found to exhibit its aptness in describing speed under such traffic and was, thereby, considered in estimating the limiting speed of slower vehicles that tends to obstruct the flow of traffic. Vehicles that move at or below this speed cause delay to the faster ones resulting in formation of platoons at moderate and heavy flow when passing is restricted. Since the percent time-spent-following, a performance measure to assess level-of-service of two-lane highways, considers proportion of vehicles that are trapped inside platoons, it is imperative to estimate the limiting speed of slower vehicles correctly to approximate the delayed vehicles.