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991.
In this paper, a methodology that can be employed to simulate radionuclide migration through unsaturated soils, under laboratory
conditions, has been developed and reported. This was achieved with the help of a specially designed half-cell setup to study
diffusion characteristics of inactive forms of Cs+, Sr+2 and Co+2 in two different types of soils, corresponding to their different compaction states. It has been noted that the apparent
diffusion coefficient strongly depends on the volumetric water content of the soil. However, increase of the apparent diffusion
coefficient for higher volumetric water contents is found to be much less as compared to the lower volumetric water contents. 相似文献
992.
P. K. Misra S. Kishore S. K. Singh A. K. Jauhri 《Journal of the Geological Society of India》2009,74(1):139-140
Discussion
Rhodophycean algae from the Lower Cretaceous of the Cauvery Basin, South India by P.K. Misra, S. Kishore, S.K. Singh and A.K. Jauhri. Jour. Geol. Soc. India, v.73, 2009, pp.325–334 相似文献993.
Arvind K. Mishra Y. K. Nigam Deepanshu R. Singh 《Journal of the Geological Society of India》2017,89(1):87-90
Except for very deep-seated deposits, open cast mining method has been recognized as the safest and most productive mode for mining minerals. Ever growing demand in minerals and coal has compelled the mine operators to increase the size of mine, which has resulted in an increasing trend towards large capacity open cast projects. Explosives and blasting techniques play a significant role in efficient opencast mining operations. There have been constant technological developments towards safer, faster, economical and more efficient blasting systems. Further, globally increased competitiveness has necessitated to carryout blasts in such a way that the desired degree of fragmentation is achieved in the primary blast, with minimum undesired side effects such as ground vibration, air blast/noise, flyrock, generation of oversize boulders, formation of toe, and over break or back break. Hence, the ultimate objective of the blasting engineer is to ensure that the blasts are carried out in an eco-friendly manner. This paper presents a case study of limestone mine where a controlled blasting was conducted near a green structure of wagon tippler (at 2 m) being constructed for foundation work of belt conveyor as the mine management wants to double the existing production. This paper deals with controlled blast design and its implementation using electronic detonators with signature hole technique. 相似文献
994.
995.
Prakash K. Singh Vijay K. Singh M. P. Singh P. K. Rajak 《Journal of the Geological Society of India》2017,90(1):9-19
The Tertiary basins of Gujarat have always been a potential target for their hydrocarbon resources. The lignite resources of the region have also been an important field of research. The present paper presents the results of the petrological study carried out on the lignites of the Saurashtra basin. For this purpose samples were collected from lower and upper lignite seams from the Surkha lignite mine of Bhavnagar, Saurashtra. These samples were subjected to detailed petrographic analysis (both maceral and microlithotype). The study reveals that these lignites are dominantly composed of huminite group macerals while liptinite and inertinite group macerals occur in subordinate amounts. These lignites have attained a thermal maturity up to 0.28-0.30 percent vitrinite reflectance (VRr) which classifies them as ‘low rank C’ coals. Moreover, Bhavnagar lower lignite seam shows relatively less gelification as compared to the upper seam which suffered relatively more biochemical degradation. These lignites are characterized by high gelification index (GI) and low tissue preservation index (TPI).With the help of petrography based facies models an attempt has been made to reconstruct the environment of the paleomire of these lignites. 相似文献
996.
K. N. D. Prasad N. Srinivas A. E. Meshram A. P. Singh V. M. Tiwari 《Journal of the Geological Society of India》2017,90(6):704-710
Koyna-Warna Region (KWR) is one of the known sites for reservoir triggered seismicity. The continued triggered seismicity over the five decades is restricted to a region of about 600–700 sq. km, which provides a unique opportunity to monitor geophysical anomalies likely to be associated with seismicity of the region. Present study confers temporal gravity changes recorded by gPhone and GRACE satellite and interprets observed changes in conjunction with seismological, geodetic (cGPS) observations and groundwater level measurements. GRACE data suggest that seasonal vertical deformation due to hydrological loading is ~ 2 cm, which corroborates with continuous GPS observations. Seasonal hydrological loading of the region, which is in a phase of reservoir loading, might be influencing the critically stressed KWR leading to the seasonal seismicity of the region. The gPhone gravity data distinctly show co-seismic gravity signals for eight earthquakes of Mw > 2 and gravity anomalies show positive correlation on a logarithmic scale with earthquake released energy. To investigate the cause of gravity changes, an estimate is made for 14th April 2012 earthquake for Mw 4.8 using fault dislocation model. The recorded gravity changes of 189 μGal by gPhone located at a distance of 28 km from the hypocentre is much more than the estimate of ~0.1 μGal calculated for Mw 4.8 Koyna earthquake. Therefore, it is inferred that co-seismic gravity signals for eight earthquakes are primarily caused due to redistribution of mass at shallow depth. 相似文献
997.
Rajesh Singh Ravi Kumar Umrao T. N. Singh 《Journal of the Geological Society of India》2017,89(3):295-302
Slope instability is very common phenomenon, especially in tectonically active hills of the lesser Himalaya. The deformed, weathered and fragile rocks of the lesser Himalaya are often vulnerable under natural or anthropogenic influences. There were several cases of slope failure along highway sections in Uttarakhand Himalaya. The study was carried out along a highway section of NH-109. The factor of safety (FoS) is commonly most acceptable parameter that analyses the health of slopes. The two dimensional (2D) numerical analysis techniques are commonly used to obtain the FoS. It is observed that many times FoS obtained from 2D analysis techniques do not qualify the actual conditions and are usually lower in value as compared to ground conditions. This, in turn, increases the cost of remedial measures used for protection of slopes. This paper presents a comparative study of 2D and 3D numerical analysis based on the finite difference method (FDM) using fast Langrangian analysis of continua (FLAC) codes. The study indicates that there is no appreciable difference between FoS values obtained from 2D and 3D analysis based on the selected slope conditions. The difference ranges from 0.02 to 0.07 for analysed cases in uniform rock mass. The study also exhibits some of the important analytical observations and effects of variables on resultant FoS. 相似文献
998.
For the socio-economic development of a country, the highway network plays a pivotal role. It has therefore become an imperative to have landslide hazard assessment along these roads to provide safety. The current study presents landslide hazard zonation maps, based on the information value method and frequency ratio method using GIS on 1:50,000 scale by generating the information about the landslide influencing factors. The study was carried out in the year 2017 on a part of Ravi river catchment along one of the landslide-prone Chamba to Bharmour road corridor of NH-154A in Himachal Pradesh, India. A number of landslide triggering geo-environmental factors like “slope, aspect, relative relief, soil, curvature, Land Use and Land Cover (LULC), lithology, drainage density, and lineament density” were selected for landslide hazard mapping based on landslide inventory. The landslide inventory has been developed using satellite imagery, Google earth and by doing exhaustive field surveys. A digital elevation model was used to generate slope gradient, slope aspect, curvature, and relative relief map of the study area. The other information, i.e., soil maps, geological maps, and toposheets, have been collected from various departments. The landslide hazard zonation map was categorized namely “very high hazard, high hazard, medium hazard, low hazard, and very low hazard.” The results from these two methods have been validated using area under curve (AUC) method. It has been found that hazard zonation map prepared using frequency ratio model had a prediction rate of 75.37% while map prepared using information value method had prediction rate of 78.87%. Hence, on the basis of prediction rate, the landslide hazard zonation map, obtained using information value method, was experienced to be more suitable for the study area. 相似文献
999.
The Surat City, which is the second most populated city in the state of Gujarat in western India, warrants site-specific seismic hazard assessment due to its rapid urbanization and proximity to major seismogenic zones. This study reports results of microtremor investigations at 72 single stations and 4 arrays in an area of 325 km2 spanning the city. The resonant frequencies, associated peak amplification values and liquefaction vulnerability indices were deduced from the horizontal to vertical spectral ratios. Ground amplification (AHVSR) in the range of 3.0–5.0 was observed in the 2.0–4.0-Hz frequency band at most of the sites. A secondary AHVSR between 2.0 and 3.0 is also observed in the 6.0–7.0-Hz frequency band at a few sites. Locales that are most susceptible to liquefaction are identified based on their vulnerability index (K g) exceeding the value of 10. The shear wave velocities (V s) ≥ 500 m/s inferred from array measurements occur at 38 m depth in the western part and ~16 m depth in the eastern part of city. The response spectra estimated from strong motion data recorded at an accelerograph site in Surat from three earthquakes of M w ≥ 3.2 that occurred in Kachchh, Saurashtra and Narmada regions are in accordance with our inferences of characteristic site frequencies and amplification. Our results, in agreement with the damage scenario during the 2001 Bhuj earthquake, provide valuable inputs for site-specific seismic hazard evaluation of the Surat City. 相似文献
1000.
P. S. Meenu S. Sowmya R. Asha Latha B. S. Shashank D. N. Singh 《Geotechnical and Geological Engineering》2017,35(2):607-614
Dependence of soil suction on factors such as formation of the soil, its particle size, mineralogy, pore-size distribution characteristics, water content, fabric, stress history and presence of salts has been extensively investigated by researchers. However, the influence of the microbial presence and its activity on the soil suction has not yet received researchers’ attention. With this in view, a methodology that facilitates investigation regarding the presence of ‘soil-microbial interface’, which has been termed as ‘bio-geo interface’, has been proposed in this study. Furthermore, the influence of this ‘interface’ on suction characteristics of such soils has also been investigated and the utility of the proposed methodology in addressing such issues, successfully, has been demonstrated. 相似文献