Pressure–settlement characteristics of rectangular footings on reinforced sand     

Arvind Kumar  Baljit Singh Walia  Swami Saran 《Geotechnical and Geological Engineering》2005,23(4):469-481

A method has been proposed to obtain the pressure–settlement characteristics of rectangular footings resting on reinforced sand based on constitutive laws of soils. The confining effect of the reinforcement provided in the soil at different layers has been incorporated in the analysis by considering the equivalent stresses generated due to friction at the soil– reinforcement interface. The prerequisite of the method is the value of ultimate bearing capacity, which can be obtained from the approaches already available in literature. The value of settlement may be read directly from pressure–settlement curves for the given pressure intensity. Therefore, the rectangular footing resting on reinforced sand can be proportioned satisfying shear failure and settlement criteria.  相似文献   

Geological and tectonic influence on water–soil–radon relationship in Mandi–Manali area,Himachal Himalaya     

V. M. Choubey  P. K. Mukherjee  B. S. Bajwa  Vivek Walia 《Environmental Geology》2007,52(6):1163-1171

Radon measurements in soil and groundwater (springs, thermal springs and handpumps) were made in a variety of lithological units including major thrusts between Mandi and Manali in Himachal Himalaya. Analysis of radon data in light of lithological controls and influence of deep-seated thrusts has been made to elucidate the causative factors for anomalous emanation of radon. The lithological types include banded gneisses, schists, quartzite, granite, phyllites, volcanics and mylonites. The low-grade metasedimentries of Shali and Dharamsala generally show low and narrow range of radon concentration in water (5.6–13.4 Bq/l) as well as in soil (1.8–3.2 kBq/m³) except for the samples related to thrusts. On the other hand, sheared and deformed rocks of Chail and Jutogh show moderate radon content (average 5.03 kBq/m³, range 2.9–11.1 kBq/m³) in soil. However, the groundwater radon concentration shows wide variation in different types of sources (2.1–80.8 Bq/l). The quartzite and volcanic rocks of Rampur formation in this area present as a window separated by Chail thrust. Radon emanations on these rock types are relatively high (6.3–68.1 Bq/l in water and 5.5–15.9 kBq/m³ in soil) and are exceptionally high in samples that are related to uranium mineralization, deep-seated thrusts and hot springs (13.5–653.5 Bq/l). It is generally observed that anomalous high radon content is associated with mineralization, deeper source and tectonic discontinuities. Whereas it is obvious that subsurface radioactive mineralization would facilitate enhanced radon production, however, thrust plains provide easy pathways for escape of gases from the deeper sources. Shallow and deep sources of the groundwater have contrasting radon content particularly in the deformed and metamorphosed rocks of Jutogh and Chail. Shallow groundwater sources, mainly handpumps, have lower radon concentration due to limited superficial water circulation, whereas deeper sources, mainly perennial springs, show higher radon content because of larger opportunity for water–rock interaction.  相似文献   

Numerical investigation on effect of varying injection scenario and relative permeability hysteresis on CO<Subscript>2</Subscript> dissolution in saline aquifer     

R. Vivek  G. Suresh Kumar 《Environmental Earth Sciences》2016,75(16):1192

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Multivariate statistical analysis approach for prediction of blast-induced ground vibration     

Vivek K. Himanshu  M. P. Roy  A. K. Mishra  Ranjit Kumar Paswan  Deepak Panda  P. K. Singh 《Arabian Journal of Geosciences》2018,11(16):460

Excavation of coal, overburden, and mineral deposits by blasting is dominant over the globe to date, although there are certain undesirable effects of blasting which need to be controlled. Blast-induced vibration is one of the major concerns for blast designers as it may lead to structural damage. The empirical method for prediction of blast-induced vibration has been adopted by many researchers in the form of predictor equations. Predictor equations are site specific and indirectly related to physicomechanical and geological properties of rock mass as blast-induced ground vibration is a function of various controllable and uncontrollable parameters. Rock parameters for blasting face and propagation media for blast vibration waves are uncontrollable parameters, whereas blast design parameters like hole diameter, hole depth, column length of explosive charge, total number of blast holes, burden, spacing, explosive charge per delay, total explosive charge in a blasting round, and initiation system are controllable parameters. Optimization of blast design parameters is based on site condition and availability of equipment. Most of the smaller mines have predesigned blasting parameters except explosive charge per delay, total explosive charge, and distance of blast face from surface structures. However, larger opencast mines have variations in blast design parameters for different benches based on strata condition: Multivariate predictor equation is necessary in such case. This paper deals with a case study to establish multivariate predictor equation for Moher and Moher Amlohri Extension opencast mine of India. The multivariate statistical regression approach to establish linear and logarithmic scale relation between variables to predict peak particle velocity (PPV) has been used for this purpose. Blast design has been proposed based on established multivariate regression equation to optimize blast design parameters keeping PPV within legislative limits.  相似文献   

Radioactivity monitoring in the vicinity of Jawalamukhi thrust NW Himalaya,India for tectonic study     

Kumar  Gulshan  Bhadwal  Reetika  Kumar  Mukesh  Kumari  Punam  Kumar  Arvind  Walia  Vivek  Mehra  Rohit  Goyal  Ayush 《Natural Hazards》2022,111(3):2219-2240

Natural Hazards - This work reports radon-thoron monitoring at two depths (60 and 90&nbsp;cm) and at 82 sites around Jawalamukhi thrust of NW Himalaya, India using Solid State Nuclear Track...  相似文献   

Approaches to the simulation of unconfined flow and perched groundwater flow in MODFLOW   总被引：1，自引：0，他引：1  

Bedekar V  Niswonger RG  Kipp K  Panday S  Tonkin M 《Ground water》2012,50(2):187-198

Various approaches have been proposed to manage the nonlinearities associated with the unconfined flow equation and to simulate perched groundwater conditions using the MODFLOW family of codes. The approaches comprise a variety of numerical techniques to prevent dry cells from becoming inactive and to achieve a stable solution focused on formulations of the unconfined, partially-saturated, groundwater flow equation. Keeping dry cells active avoids a discontinuous head solution which in turn improves the effectiveness of parameter estimation software that relies on continuous derivatives. Most approaches implement an upstream weighting of intercell conductance and Newton-Raphson linearization to obtain robust convergence. In this study, several published approaches were implemented in a stepwise manner into MODFLOW for comparative analysis. First, a comparative analysis of the methods is presented using synthetic examples that create convergence issues or difficulty in handling perched conditions with the more common dry-cell simulation capabilities of MODFLOW. Next, a field-scale three-dimensional simulation is presented to examine the stability and performance of the discussed approaches in larger, practical, simulation settings.  相似文献   

Hydrological behavior of Umshing River,East Khasi Hills,Meghalaya     

Devesh Walia  Bijay S. Mipun 《Acta Geophysica》2010,58(5):908-921

The morphometric and drainage basin analysis of the Umshing River is carried out quantitatively using remote sensing and GIS techniques. The results are presented concerning the hydrological behavior of Umshing river in order to define multi-scale geomorphometric landform types. The Umshing basin shows a sub-trellis drainage pattern indicating the litho-structural control on the drainage. Lithological, structural and geomorphological features control the directions of flow of the tributaries. It is observed and inferred that the Umshing river catchment is under the stage of creep or tilting and hence is vulnerable to geohazard.  相似文献   

Seismotectonic zones demarcation in the Shillong Plateau using the microearthquakes and radon emanation rate     

Devesh Walia  Andrew C. Lyngdoh  Atul Saxena 《Acta Geophysica》2010,58(5):893-907

The Shillong Plateau signifies the intense tectonic processes that the region has experienced during the Tertiary Indo-Tibetan and Indo-Burman collisions. An attempt has been made to study the microearthquake and radon emanation rate to understand and identify the seismotectonic zones.  相似文献   

Real-time database for geochemical earthquake precursory research     

Kumar  Arvind  Walia  Vivek  Lin  Shih-Jung  Fu  Ching-Chou 《Natural Hazards》2020,104(2):1359-1369

Natural Hazards - In the present research for the first time, an effort has been made to create an online real-time database for geochemical earthquake precursory research. The manually operating...  相似文献   

Axisymmetric Modeling Using MODFLOW-USG     

Vivek Bedekar  Leland Scantlebury  Sorab Panday 《Ground water》2019,57(5):772-777

Axisymmetric groundwater models are used for simulating radially symmetric conditions. Groundwater simulators built specifically to model axisymmetric conditions are most commonly used for simulating aquifer tests. Although some numerical models capable of simulating flow and solute transport that are developed in the cartesian coordinate system framework offer flexibility to simulate axisymmetric conditions, most of the numerical groundwater models, such as the MODFLOW family of codes, are based on structured grids in which axisymmetric flows cannot be directly simulated. Researchers in the past have provided methods to manipulate aquifer properties to mimic axisymmetric conditions. This study presents a methodology that takes advantage of the unstructured grids of MODFLOW-USG to simulate axisymmetric models within the MODFLOW framework. To develop axisymmetric models, the intercell interface area arrays of MODFLOW-USG were calculated to accurately represent coaxial cylindrical model cells. Three examples are presented to demonstrate the application of MODFLOW-USG for axisymmetric modeling: a pumping well with delayed yield effects, a vadose zone flow model simulating an infiltration basin, and a density-dependent saltwater intrusion problem for a circular island. Results were verified against analytical solutions and published numerical codes.  相似文献