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Stability investigation of road cut slope in basaltic rockmass,Mahabaleshwar,India

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Geoscience Frontiers 2015年第6期6卷 837-845页

作者： Ashutosh kainthola p.k.singh T.N.singh Department of Earth Sciences Indian Institute of Technology Bombay

Slope failures along hill cut road slopes are the major nuisance for commuters and highway planners as they put the human lives at huge risk,coupled with immense monetary *** of these vulnerable cut slopes entails the assessment and estimation of the suitable material strength input parameters to be used in the numerical models to accomplish a holistic stability *** the present study a 60 m high,basaltic and lateritic road cut hill slope in Mahabaleshwar,India,has been considered.A number of samples of both basalt and laterite,in their natural state were tested in the laboratory and the evaluated maximum,minimum and mean strength parameters were employed for the three cases in a distinct element numerical *** Mohr-Coulomb failure criterion has been incorporated in the numerical model for the material as well as the *** numerical investigation offered the factor of safety and insights into the probable deformational mechanism for the three ***,several critical parameters have also been judged from the study viz.,mode of failure,factor of safety,shear strain rate,displacement magnitudes *** result of this analysis shows that the studied section is prone to recurrent failures due to the capping of a substantially thick layer of weaker lateritic material above the high strength basaltic rock *** triggering mechanisms like heavy precipitation and earthquake may also accelerate the slope failure in this *** study also suggests employing instant preventive measures to avert the further risk of damage.

关键词： Slope stability UDEC Basalt Mahabaleshwar Road cut

poverty alleviation and resource conservation through development of cost effective technology at foot hill of Shivalik - A case study

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International Journal of Agricultural and Biological Engineering 2013年第3期6卷 34-40页

作者： R kumar p k singh B A Langoo Division of Agricultural Engineering Sher-e-Kashmir Univeristy of Agricultural Sciences and Techonology of KashmirSrinagar(J&K)India Department of soil and water Engineering College of Technology and EngineeringUdaipur(Raj)India

The study revealed the development of cost effective technology utilized as a practical tool for treatment of seasonal torrent and addressing erosion problems and land use *** was implemented in a small agricultural watershed located in foot hill of Shivalik,India,to assess its prediction capacity of runoff,peak runoff flow and sediment *** effective technology was evaluated at the event scale by using a database of hydrological,geomorphologic and land use data collected during a two-year *** the catchment,the gullies which are small to medium in size were treated with gully plugging by erecting loose boulder check dams and erected with different species of *** types of spur were constructed with vegetative reinforcement for channelization of stream *** sediments deposited in the first year at downstream was recorded 0.09-81.0 tons,while in the second year it was reduced up to 0.07-16.7 ***,up stream sediment deposition was recorded 1.0-72.0 tons and 0.37-13.1 tons in two consecutive *** D-50 analysis of sediment deposited was carried in three different places of torrent and it was found that deposited particle size material decreased after treatment undertaken in the torrent ***,the mechanical as well as vegetative measures helped in the channelization of water course towards the central line with the tune of 10-100 m,stabilization of torrent bed and reclamation of degraded land.

关键词： Integrated watershed management mechanical measures D-50 vegetative measures

Eocene lignites from Cambay basin, Western India： An excellent source of hydrocarbon

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Geoscience Frontiers 2016年第5期7卷 811-819页

作者： p.k.singh V.k.singh p.k.Rajak M.p.singh A.S.Naik S.V.Raju D.Mohanty Coal & Organic petrology Lab Centre of Advanced Study in Geology Banaras Hindu University Varanasi 221005 Uttar Pradesh India Research & Development Oil India Limited Duliajan Assam 786 602 India Central Institute of Mining and Fuel Research Barwa Road Dhanbad 826015 India

In the present paper lignites from the Cambay basin have been studied for their hydrocarbon *** samples were collected from three lignite fieldse Vastan, Rajpardi and Tadkeshwar, and were investigated by petrography, chemical analyses and Rock-Eval pyrolysis. The results are well comparable with the empirically derived values. The study reveals that these ‘low rank C＇ lignites are exceedingly rich in reactive macerals（huminite t liptinite） while inertinite occurs in low concentration. These high volatile lignites generally have low ash yield except in few sections. The Rock-Eval data indicates the dominance of kerogen type-III with a little bit of type-II. The study reveals that the lignites of Vastan（lower and upper seams） and Tadkeshwar upper seam are more gas-prone while Rajpardi and Tadkeshwar lower seams are oil-prone. Further, the fixed hydrocarbons are several times higher than the free hydrocarbons. The relation between TOC and fixed hydrocarbon indicates that these lignites are excellent source rock for hydrocarbon which could be obtained mainly through thermal cracking. The empirically derived values reveal a high conversion（94e96%） and high oil yield（64e66%） for these lignites.

关键词： Eocene lignites Cambay basin Rock-Eval Maceral Hydrocarbon

Numerical analysis of surface subsidence in asymmetric parallel highway tunnels

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第1期9卷 170-179页

作者： Ratan Das p.k.singh Ashutosh kainthola Suman panthee T.N.singh Department of Earth Sciences Indian Institute of Technology Bombay Department of Civil Engineering National Institute of Technology Central Department of Geology Tribhuvan University

Tunnelling related hazards are very common in the Himalayan terrain and a number of such instances have been reported. Several twin tunnels are being planned for transportation purposes which will require good understanding for prediction of tunnel deformation and surface settlement during the engineering life of the structure. The deformational behaviour, design of sequential excavation and support of any jointed rock mass are challenging during underground construction. We have raised several commonly assumed issues while performing stability analysis of underground opening at shallow depth. For this purpose, kainchi-mod Nerchowck twin tunnels(Himachal pradesh, India) are taken for in-depth analysis of the stability of two asymmetric tunnels to address the influence of topography, twin tunnel dimension and geometry. The host rock encountered during excavation is composed mainly of moderately to highly jointed grey sandstone, maroon sandstone and siltstones. In contrast to equidimensional tunnels where the maximum subsidence is observed vertically above the centreline of the tunnel, the result from the present study shows shifting of the maximum subsidence away from the tunnel centreline. The maximum subsidence of 0.99 mm is observed at 4.54 m left to the escape tunnel centreline whereas the maximum subsidence of 3.14 mm is observed at 8.89 m right to the main tunnel centreline. This shifting clearly indicates the influence of undulating topography and inequidimensional noncircular tunnel.

关键词： Twin tunnels Numerical analysis Stability Finite element method(FEM) Subsidence

Microstructure and mechanical properties of friction welded carbon steel(EN24) and nickel-based superalloy(IN718)

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International Journal of Minerals,Metallurgy and Materials 2021年第1期28卷 111-119页

作者： V.T.Gaikwad M.k.Mishra V.D.Hiwarkar R.k.p.singh kalyani Centre for Technology and Innovation Bharat Forge LimitedPune 411036India Department of Materials Engineering Defense Institute of Advance TechnologyPune 411025India

Continuous-drive rotary friction welding was performed to join cylindrical specimens of carbon steel(EN24) and nickel-based superalloy(IN718), and the microstructures of three distinct weld zones—the weld interface(WI)/thermo-mechanically affected zone(TMAZ),the heat-affected zone(HAZ), and the base metal—were *** joint was observed to be free of defects but featured uneven flash *** backscatter diffraction(EBSD) analysis showed substantial changes in high-angle grain boundaries, low-angle grain boundaries, and twin boundaries in the TMAZ and ***, significant refinement in grain size(2 –5 μm) was observed at the WI/TMAZ with reference to the base *** possible causes of these are *** microhardness profile across the welded joint shows variation in *** changes in hardness are ascribed to grain refinement, phase transformation, and the dissolution of strengthening *** tensile test results reveal that a joint efficiency of 100% can be achieved using this method.

关键词： friction welding dissimilar metals EN24 IN718 microstructure mechanical properties

Control of rock joint parameters on deformation of tunnel opening

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第4期8卷 489-498页

作者： Suman panthee p.k.singh Ashutosh kainthola T.N.singh Central Department of Geology Tribhuvan University Department of Earth Sciences Indian Institute of Technology Bombay

In this paper, stress behavior of shallow tunnels under simultaneous non-uniform surface traction and symmetric gravity loading was studied using a direct boundary element method（BEM）. The existing fullplane elastostatic fundamental solutions to displacement and stress fields were used and implemented in a developed algorithm. The cross-section of the tunnel was considered in circular, square, and horseshoe shapes and the lateral coefficient of the domain was assumed as unit quantity. Double-node procedure of the BEM was applied at the corners to improve the model including sudden traction changes. The results showed that the method used was a powerful tool for modeling underground openings under various external as well as internal loads. Eccentric loads significantly influenced the stress pattern of the surrounding tunnel. The achievements can be practically used in completing and modifying regulations for stability investigation of shallow tunnels.

关键词： Stress behavior Boundary element method(BEM) Shallow tunnels Eccentricity

petrographic characteristics coals, Mahanadi Gondwana and paleomires of Mand-Raigarh Basin, Chhattisgarh, India

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International Journal of Coal Science & Technology 2016年第2期3卷 165-183页

作者： A. S. Naik M. p. singh N. Volkmann p. k. singh D. Mohantya D. kumar Banaras Hindu University Varanasi India T U Bergakademie Freiberg Germany CSIR-Central Institute of Mining and Fuel ResearchDhanbad India

Mand-Raigarh coalfield is one of the largest coalfields in the Mahanadi basin. The Geological Survey of India carried out initial study primarily on exploration. However, detailed petrographic and geochemical characters of the coals have not been done so far. This investigation is an attempt for petrographic and geochemical appraisal of the coals. Moreover, effort is also made for possible interpretation on development of coal facies. The results drawn from 30 composite coal samples suggest coals are rich in vitrinite, with collotelinite as the dominant maceral while liptinite macerals register low concentration. Dominant mineral assemblages found were clay minerals, pyrite was recorded as disseminated, framboidal and euhedral forms, carbonates recorded were mainly siderites. The vitrinite reflectance random （VRo） mean values range from 0.44 % to 0.56 %, and the rank of coal is suggested as high volatile ＇B＇ to ＇A＇ sub- bituminous in rank. The rock-eval pyrolysis reveal TOC content varying from 37 % to 68.83 %, while low hydrocarbon generating potential is evident from low $2 and Tmax values. The Hydrogen Index （HI） versus Oxygen Index （OI） plot reveal that the samples belong to kerogen type--II-III with input dominantly from terrestrial source, some samples also fall in kerogen type--II domain indicating lacustrine input. Vitrinite reflectance result indicate that the samples are immature and approaching oil window, which is in agreement with data of the Rock-Eval parameters. The gelification index （GI） and tissue preservation index （TpI） indicate that the coal developed in a telematic set up with high tree density. The ground water index （GWI） and vegetation index （VI） demonstrate that the peat developed as an ombrogenous bog.

关键词： Mand-Raigarh coalfield Organic petrology Geochemistry Source rock

Rock fragmentation control in opencast blasting

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第2期8卷 225-237页

作者： p.k.singh M.p.Roy R.k.paswan Md.Sarim Suraj kumar Rakesh Ranjan Jha CSIR-Central Institute of Mining and Fuel Research

The blasting operation plays a pivotal role in the overall economics of opencast *** blasting subsystem affects all the other associated sub-systems,***,transport,crushing and milling *** control through effective blast design and its effect on productivity are the challenging tasks for practicing blasting engineer due to inadequate knowledge of actual explosive energy released in the borehole,varying initiation practice in blast design and its effect on explosive energy release *** paper describes the result of a systematic study on the impact of blast design parameters on rock fragmentation at three mines in *** mines use draglines and shoveledumper combination for removal of *** its pivotal role in controlling the overall economics of a mining operation,the expected blasting performance is often judged almost exclusively on the basis of poorly defined parameters such as powder factor and is often qualitative which results in very subjective assessment of blasting *** an approach is very poor substitutes for accurate assessment of explosive and blasting *** one blasts were conducted with varying blast designs and charging patterns,and their impacts on the rock fragmentation were documented.A high-speed camera was deployed to record the detonation sequences of the *** efficiency of the loading machines was also correlated with the mean fragment size obtained from the fragmentation analyses.

关键词： Opencast blast Rock fragmentation Explosives performance Dragline efficiency Fragment size

Analysis of groundwater level trend in Jakham River Basin of Southern Rajasthan

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Journal of Groundwater Science and Engineering 2022年第1期10卷 1-9页

作者： Vinay kumar Gautam Mahesh kothari p.k.singh S.R.Bhakar k.k.Yadav Department of Soil and Water Engineering CTAEMPUATUdaipur-313001(Raj.)India

Groundwater accounts for about half of the water use for irrigation in *** fluctuation pattern of the groundwater level is examined by observing rainfall replenishment and monitoring *** southern part of Rajasthan has experienced abrupt changes in rainfall and has been highly dependent on groundwater over *** study presents the impact of over-dependence on groundwater usage for irrigation and other purposes,spatially and ***,the objective of this study is to examine the groundwater level trend by using statistical analysis and geospatial *** factor was also studied in groundwater level fluctuation during *** analyze the influence of each well during recharge or withdrawal of groundwater,thiessien polygonswere generated from *** the Jakham River basin,75 wells have been identified for water level trend study using the Mann-kendall statistical *** statistics of trend analysis show that 15%wells are experiencing water level decline in pre-monsoon,while very low percentage of wells have such trend during post-monsoon *** average rate of water level decline is 0.245 m/a in pre-monsoon and 0.05 m/a in *** aquifer recharge potential is also decreasing by *** is expected that such type of studies will help the policy makers to adopt advanced management practices to ensure sustainable groundwater resource management.

关键词： Groundwater Trend analysis Rainfall kendal tau Slope p value Recharge pre-and postmonsoon