Model Pile Groups Under Oblique Pullout Loads – an Investigation     

Nihar Ranjan Patra  Prabhakar Jagannath Pise 《Geotechnical and Geological Engineering》2006,24(2):265-282

Experimental investigations on model pile groups of configuration, 1 × 1(single pile), 3 × 1, 2 × 2 for embedment length to diameter ratio, L/d = 38, were conducted in uniform dry medium dense Ennore sand. The spacing of piles in the groups varied from 3 to 6 pile diameter. Soil–pile friction angles were δ = 16° and 28°. The pile groups were subjected to oblique pulling loads at angles θ = 0°, 30°, 60° and 90° with the vertical central axis of the groups. The load–displacement response, oblique ultimate pulling resistances have been qualitatively and quantitatively studied. The inclinations of the load, at which maximum oblique resistance for the groups were observed, have been reported. Predictions of ultimate resistance of pile groups under uplift, lateral and oblique pulling loads have been carried out respectively by the methods of Patra and Pise (2002) (Electronic Journal of Geotechnical Engineering, 8, Bundle B), Patra and Pise (2001) (Journal of Geotechnical and Geoenvironmental Engineering ASCE, 127(6), 481–487) and Chattopadhyay and Pise (1986c) (Proceedings of IST East Asian Conference on Struct Engineering and Const., Vol. 1, pp. 1632–1641). A comparison of the measured values of the Writers and others with the predicted values showed reasonable agreement.  相似文献   

Biostratigraphy and floristic evolution of coal swamp floras of a part of Talcher Basin,India: a window on a Permian temperate ecosystem     

Shreerup Goswami  Kamaljyoti Das  Mrutyunjaya Sahoo  Soumyaranjan Bal  Sanghamitra Pradhan  Kamal Jeet Singh  Anju Saxena 《Arabian Journal of Geosciences》2018,11(17):524

The present megafloral assemblage recorded from the Barakar sediments of Dholpahar section along Singda rivulet near Gopal Prasad Village in Talcher Basin comprises of equisetaceous stems, Gangamopteris buriadica, Palaeovittaria kurzii and 19 species of the genus Glossopteris. Record of Gangamopteris, Palaeovittaria and many narrow mesh forms of Glosspteris viz., G. angustifolia, G. churiensis, G. communis, G. recurva, G. spatulata, G. stenoneura, G. tenuifolia, G. vulgaris and G. zeilleri from two older fossiliferous horizons demonstrates that these fossils were preserved during Lower Barakar sedimentation. The report of middle and broad mesh forms of Glossopteris viz., G. barakarensis, G. browniana, G. indica, G. intermittens, G. karharbariensis, G. nakkarea, G. oldhamii, G. taeniensis and G. retifera in the youngest fossiliferous horizons reveals that these fossils were preserved during the deposition of Upper Barakar sediments. The continuation of some of the Karharbari plant fossils in the early phase of Barakar Formation and their disappearance in the flora of Late Barakar suggests a shift in the climatic setup. Palaeoclimate and palaeovegetation of this area are also summarised in this study. Moreover, the fossil assemblages of different fossiliferous beds of Dholpahar section demonstrate the evolution of midrib and meshes in different reticulate leaves.  相似文献   

Impact of LULC change on the runoff,base flow and evapotranspiration dynamics in eastern Indian river basins during 1985–2005 using variable infiltration capacity approach     

Pulakesh Das  Mukunda Dev Behera  Nitesh Patidar  Bhabagrahi Sahoo  Poonam Tripathi  Priti Ranjan Behera  S K Srivastava  Partha Sarathi Roy  Praveen Thakur  S P Agrawal  Y V N Krishnamurthy 《Journal of Earth System Science》2018,127(2):19

As a catchment phenomenon, land use and land cover change (LULCC) has a great role in influencing the hydrological cycle. In this study, decadal LULC maps of 1985, 1995, 2005 and predicted-2025 of the Subarnarekha, Brahmani, Baitarani, Mahanadi and Nagavali River basins of eastern India were analyzed in the framework of the variable infiltration capacity (VIC) macro scale hydrologic model to estimate their relative consequences. The model simulation showed a decrease in ET with 0.0276% during 1985–1995, but a slight increase with 0.0097% during 1995–2005. Conversely, runoff and base flow showed an overall increasing trend with 0.0319 and 0.0041% respectively during 1985–1995. In response to the predicted LULC in 2025, the VIC model simulation estimated reduction of ET with 0.0851% with an increase of runoff by 0.051%. Among the vegetation parameters, leaf area index (LAI) emerged as the most sensitive one to alter the simulated water balance. LULC alterations via deforestation, urbanization, cropland expansions led to reduced canopy cover for interception and transpiration that in turn contributed to overall decrease in ET and increase in runoff and base flow. This study reiterates changes in the hydrology due to LULCC, thereby providing useful inputs for integrated water resources management in the principle of sustained ecology.  相似文献   

Influence of Gassing Agent and Density on Detonation Velocity of Bulk Emulsion Explosives     

Arvind Kumar Mishra  Manamohan Rout  Deepanshu Ranjan Singh  Sakti Pada Jana 《Geotechnical and Geological Engineering》2018,36(1):89-94

The demand for coal from surface mining projects are on the higher side like never before for which blasting is the basic unit operation. The explosive plays an important role in blasting and also influence the explosive-rock interaction. The most common explosive type used in surface mines is emulsion explosives. This paper presents the study on the detonation velocity of bulk emulsion explosives due to variation in gassing agent and density. In this study Sodium Nitrite (NaNO₂) has been used as the gas generating additive and the performance of emulsion explosives with different concentrations of gassing agents at different temperatures has been observed. This study was undertaken to also understand the cyclic variation of temperature on gassing kinetics and performance of explosive. The effect of cooling on detonic-behaviour of bulk emulsion explosives has also been studied and presented in this paper.  相似文献   

Evaluation of NDWI and MNDWI for assessment of waterlogging by integrating digital elevation model and groundwater level   总被引：1，自引：0，他引：1  

Kanwar Vivek Singh  Shashikanta Sahoo  Avinash Prasad  Brijendra Pateriya 《国际地球制图》2015,30(6):650-661

Accurate information on the extent of waterlogging is required for flood prediction, monitoring, relief and preventive measures. The rule-based classification algorithms were used for differentiating waterlogged areas from other ground features using Resourcesat-2 AWiFS satellite imagery (Indian Remote Sensing Satellite with spatial resolution of 56 m). Two spectral indices normalized difference water index (NDWI) and modified normalized difference water index (MNDWI) were used for extracting waterlogged areas in Sri Muktsar Sahib district of Punjab, India. These indices extracted the waterlogged areas (cropped areas inundated with water) but the water features were less enhanced in the NDWI-derived image (when compared with MNDWI-derived image) due to negative values of NDWI and, mixing of water with built up features. The water features were more enhanced with MNDWI and the values of MNDWI were positive for water features mixed with vegetation. The overall accuracy of waterlogged areas extracted from the MNDWI image was 96.9% with the Kappa coefficient of 0.89. The digital elevation model (DEM) was extracted from ASTER-GDEM. The relationships among depth to the water table recorded before the incessant rain in the region, DEM and classified MNDWI images explained the differences in the extent of waterlogging in various directions of the study area. These results suggest that MNDWI can be used to better delineate water features mixed with vegetation compared to NDWI.  相似文献   

A model of producer incentives for livestock disease management     

Ram Ranjan  Ruben N. Lubowski 《Stochastic Environmental Research and Risk Assessment (SERRA)》2005,19(5):315-325

We examine the management of livestock diseases from the producers‘ perspective, incorporating information and incentive asymmetries between producers and regulators. Using a stochastic dynamic model, we examine responses to different policy options including indemnity payments, subsidies to report at-risk animals, monitoring, and regulatory approaches to decreasing infection risks when perverse incentives and multiple policies interact. This conceptual analysis illustrates the importance of designing efficient combinations of regulatory and incentive-based policies.

Ram RanjanEmail:

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Fish behaviour and orientation-dependent backscatter in acoustic Doppler profiler data     

Zedel  Len; Patro  Ranjan; Knutsen  Tor 《ICES Journal of Marine Science》2005,62(6):1191-1201

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Grey analytic hierarchy process applied to effectiveness evaluation for groundwater potential zone delineation     

Satiprasad Sahoo  Amlanjyoti Kar  Prahlad Ram 《国际地球制图》2017,32(11):1188-1205

An attempt has been made to identify plausible groundwater potential zones (GWPZ) based on Grey Analytic Hierarchy Process Method (Grey-AHP) using integrated remote sensing and geographic information system. Grey-AHP combines the advantages of classical analytic hierarchy process and grey clustering method for accurate estimation of weight coefficients. The method also examines the effectiveness of GWPZ identification process. The proposed methodology has been applied to the Hirakud canal command area, Odisha (India). Feature layers [e.g. soil type, geology] are utilized for groundwater potential index (GWPI) calculation. The resulting GWPI map has been classified into three GWPZ namely: good, moderate and poor. Effectiveness based on grey clustering method is found to be in between ‘better’ and ‘common’ classes. Value of coefficient of determination (R² = 0.865) supports the obtained effectiveness evaluation result. This analysis demonstrates the potential applicability of the methodology for a general aquifer system.  相似文献   

Delineation of structural features over a part of the Bay of Bengal using total and balanced horizontal derivative techniques     

Satya Narayan  Soumyashree Debasis Sahoo  Ujjawal Kumar  Vipin Kumar Pathak  T. J. Majumdar 《国际地球制图》2017,32(4):351-366

The present study deals with classical problem of edge detection in potential field data over complex tectonic regime for both shallower and deeper sources, simultaneously. Balanced horizontal derivative (BHD) technique is a latest edge detection concept which delineates edges using balancing of amplitude responses for both shallower and deeper sources. The BHD technique has been validated by comparing with total horizontal derivative (THD) technique. Initially, three different synthetic models have been generated with spherical, cylindrical and vertical prismatic objects at different depths and corresponding gravity responses have been enhanced using BHD and THD techniques. Structural features have been delineated from EIGEN6C4 free-air gravity data using THD and BHD techniques over a part of the Bay of Bengal. Major lineaments have been identified in N–S direction followed by those identified along the NE–SW, NW–SE and E–W directions. Both studies of synthetic models and real gravity data reveal that BHD is an advanced technique than THD.  相似文献   

Petrology, 40Ar/39Ar age,Sr-Nd isotope systematics,and geodynamic significance of an ultrapotassic (lamproitic) dyke with affinities to kamafugite from the easternmost margin of the Bastar Craton,India     

N. V. Chalapathi Rao  Atiullah  R. Burgess  Purnendu Nanda  A. K. Choudhary  Samarendra Sahoo  B. Lehmann  Ngazipmi Chahong 《Mineralogy and Petrology》2016,110(2-3):269-293

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