Dr. Matrika Prasad Koirala
Tribhuvan University, Geology, Faculty Member
- Water, Natural Resources, Environmental Studies, Environmetal Earth Science, Water quality, Geoinformatics, and 13 moreHydrochemistry, Waste, Waste recycling, Environmental Management, Geothermal, Geostatistics, Geology, Glaciology, Hydrology, Hydrogeology, Paleontology, Geophysics, and Geographic Information Systems (GIS)edit
- I am Matrika Prasad Koirala from Nepal. After Schooling I choose Science as my major (Physics, Chemistry, Math) and g... moreI am Matrika Prasad Koirala from Nepal. After Schooling I choose Science as my major (Physics, Chemistry, Math) and got admission in Faculty of Science, Mechi Multiple Campus, Tribhuvan University, Jhapa (July1993-June1995). I chose Physics, Math and Geology in my Undergraduate studies and did B. Sc. from Tri-Chandra Multiple Campus, Ghantaghar , Kathmandu, Nepal majoring Geology (July1996-June1999). I joined Central Department of Geology, Tribhuvan University, Kirtipur for my further study in Geology and did M. Sc. in Engineering Geological Techniques (Dec.1999-Dec.2001). I taught from 2003 -2006 in Central Department of Geology and Department of Geology (Tri-Chandra Multiple Campus),Tribhuvan University. I did my second Master in Science majoring Simulation Tectonics (Sept. 2006-Sept. 2008) from University of the Ryukyus. I got my Ph.D. Degree (Sept 2011) from University of the Ryukyus.edit
A Publication of Nepalese Community of Northwest America (British Columbia, Canada, Washington and Oregon, USA). Issue 7. Includes activities of different Nepalese organization of North West America as well as articles and literary... more
A Publication of Nepalese Community of Northwest America (British Columbia, Canada, Washington and Oregon, USA). Issue 7. Includes activities of different Nepalese organization of North West America as well as articles and literary creation of people of Nepalese Origin.
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A Publication of Nepalese Students' Association In Japan
A Publication of Nepalese Students' Association In Japan
A Publication of Nepalese Students' Association in Japan
Research Interests:
F E modeling under plane stress condition is used to analyze the state of stress in and around the San Andreas Fault (SAF) system taking whole area of California. In this study I mainly focus on the state of stress at the general... more
F E modeling under plane stress condition is used to analyze the state of stress in and around the San Andreas Fault (SAF) system taking whole area of California. In this study I mainly focus on the state of stress at the general seismogenic depth of 12 km, imposing elastic rheology. The purpose of the present study is to simulate the regional stress field, displacement vectors and failures. Stress perturbation due to major fault, its geometry and major branches are analyzed. Depthwise variation from 20km to 0.5 km is considered for the fault type analysis. Series of calculations are performed with the parametrical variations of domain properties and are applied for the strong/weak SAF. All the simulated results are finally utilized for the implication of present day plate kinematics. Although in nature there is lateral and vertical variations in rheology within single domain and different domains (not considered in this study), our simulated results are comparable with the observed data. The imposed boundary condition (fixed North American plate, Pacific plate motion along N34°W vector up to northern terminus of the San Andreas faults and N50°E vector motion for the subducting Gorda and Juan de Fuca plates) have simulated the present day regional σHmax orientation and displacement vector. Simulated results show some local effect on the stress field and displacement vector by the main strand of the fault and probably its geometry and branch (Garlock Fault). Probably the low angle σHmax orientation to the strike of the SAF system in the South California (although there are some high angle σHmax orientation in southeastern California) compared to the Central and Northern California is due to the big bend and the Garlock Fault. This modeling had also beautifully simulated the left lateral strike slip movement on the Garlock Fault. Failure analysis performed based on Byerlee’s law directly tests the strong SAF and variation of physical parameters in the Mohr-Coulomb failure criterion is utilized to test relatively strong/weak SAF. Our simulated results (like stress, displacement vector, and failures) in the weak fault in relatively strong crust conditions has more or less reproduced comparable and theoretically correct results, allowed us to favor Weak fault in relatively strong crust. Depthwise variation of the fault type reveal that as the depth increases, the fault types are generally normal and at shallow depth more strike slip and thrust faults are formed. In conclusion that SAF may terminate as a low angle normal fault (detachment) at the depth.
The study area lies in the central Nepal, lesser Himalaya and includes the area of Kathmandu, Nuwakot and Dhading District of the Bagmati Zone. The climatic type of the study area varies from Cwb to Cfa according to Koeppan system of... more
The study area lies in the central Nepal, lesser Himalaya and includes the area of Kathmandu, Nuwakot and Dhading District of the Bagmati Zone. The climatic type of the study area varies
from Cwb to Cfa according to Koeppan system of climatic classification .Geologically, the study area consists of lower three formations of Phulchowki Group of Kathmandu Complex from bottom to top these formations are Tistung Formation, Sopyang Formation and Chandragiri Limestone. The Sheopuri Gneiss is interfingered within the Tistung Formation and continuous towards north. The Tistung Formation consists essentially of metasandstone and siltstone with occasional slate and phyllite. In the Northern part of the Tistung formation, concordant as well as occasional discordant granite intrusions are found Sopyang Formation consists of alternating lithology of medium to fine grained calcareous greenish grey metasandstone and medium bedded light grey dolomite moreover thinly bedded green Phyllite is also common in some places. The main rock type of Chandragiri Limestone is siliceous limestone in the weathered outcrop the rock possess yellow or brown colour. The gneiss comprises muscovite-biotite of different appearances: fine to coarse grained banded gneisses ribbon gneiss and augen gneiss which consists of quartz and feldspar. Sheopuri crystalline gneiss also consists of tourmaline-muscovite granite. The alignment studied between Km. 0+000 and Km. 8+300 of the Tinpiple Banchare Dada
Road lies in the Lesser Himalaya. The Road is aligned through the Tistung Formation. The Road crosses two major streams namely Thulo Khola and Kolpu Khola with the Bridge over them.
Almost all part of the road is aligned through the soil slope of depth greater than 6m and through some rock outcrops. Almost all part of the road is aligned through cultivated land and settlement. Almost all part of the road is aligned through middle slope and lower slope of the hill. Most of the soil type in the alignment is classified as SM and SC. Most of the Road is aligned through the residual soil. Major portion of the road section falls on the medium hazard zone. Negligible part of the road is aligned through the rock slope and falls under the category of medium hazard zone. Most of the unstable part of the Road is due to high cut slope. Dominant and pronounced unstable part of the Road can be stabilized by using the simple Bioengineering Techniques with combination of minor civil engineering structures. The effective bioengineering technique recommended for bioengineering site are combination of Jute netting and diagonal grass line, the contour grass lines or Jute netting and randomly planted grass, down slope grass lines and vegetated stone pitched rills, shrub or tree planting, turfing. For the maintenance of bio-engineering site activities like Protection of site, weeding, mulching, grass cutting and exceptional watering are recommended.
from Cwb to Cfa according to Koeppan system of climatic classification .Geologically, the study area consists of lower three formations of Phulchowki Group of Kathmandu Complex from bottom to top these formations are Tistung Formation, Sopyang Formation and Chandragiri Limestone. The Sheopuri Gneiss is interfingered within the Tistung Formation and continuous towards north. The Tistung Formation consists essentially of metasandstone and siltstone with occasional slate and phyllite. In the Northern part of the Tistung formation, concordant as well as occasional discordant granite intrusions are found Sopyang Formation consists of alternating lithology of medium to fine grained calcareous greenish grey metasandstone and medium bedded light grey dolomite moreover thinly bedded green Phyllite is also common in some places. The main rock type of Chandragiri Limestone is siliceous limestone in the weathered outcrop the rock possess yellow or brown colour. The gneiss comprises muscovite-biotite of different appearances: fine to coarse grained banded gneisses ribbon gneiss and augen gneiss which consists of quartz and feldspar. Sheopuri crystalline gneiss also consists of tourmaline-muscovite granite. The alignment studied between Km. 0+000 and Km. 8+300 of the Tinpiple Banchare Dada
Road lies in the Lesser Himalaya. The Road is aligned through the Tistung Formation. The Road crosses two major streams namely Thulo Khola and Kolpu Khola with the Bridge over them.
Almost all part of the road is aligned through the soil slope of depth greater than 6m and through some rock outcrops. Almost all part of the road is aligned through cultivated land and settlement. Almost all part of the road is aligned through middle slope and lower slope of the hill. Most of the soil type in the alignment is classified as SM and SC. Most of the Road is aligned through the residual soil. Major portion of the road section falls on the medium hazard zone. Negligible part of the road is aligned through the rock slope and falls under the category of medium hazard zone. Most of the unstable part of the Road is due to high cut slope. Dominant and pronounced unstable part of the Road can be stabilized by using the simple Bioengineering Techniques with combination of minor civil engineering structures. The effective bioengineering technique recommended for bioengineering site are combination of Jute netting and diagonal grass line, the contour grass lines or Jute netting and randomly planted grass, down slope grass lines and vegetated stone pitched rills, shrub or tree planting, turfing. For the maintenance of bio-engineering site activities like Protection of site, weeding, mulching, grass cutting and exceptional watering are recommended.
This paper deals with foundation characteristics of the soils of different parts of Nepal. In this paper, multiple approaches were adopted to explore foundation characteristic s of the soil. In this study 14 sites from different parts of... more
This paper deals with foundation characteristics of the soils of different parts of Nepal. In this paper, multiple approaches were adopted to explore foundation characteristic s of the soil. In this study 14 sites from different parts of the country were selected; 2 sites from the hilly region, 2 sites from the inner Terai and 10 sites from the Terai. In each site two test sites were selected. In each test site simplified penetration apparatus (SPA) tests were carried out and were accompanied by the auger tests. Soil samples from different depths in each site were collected for the direct shear test, soil classification, LL PL test, density and other tests and these tests were carried out in laboratory. Bearing capacity of the soils thus obtained from the laboratory was compared with the soil types of certain depth and the Nc value at that depth. From the study it was found that the Nc value depends upon the types of the soil and the compactness of the soils. This study showed that...
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Research Interests:
Page 70. 56 Sixth Nepal Geological Congress Elasto-plastic finite element modeling along the project INDEPTH profile: implication for the role of crustal strength variations in Himalaya and Tibet * Matrika Prasad Koirala and ...
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This paper describes about field study as well as laboratory test performed for the geotechnical properties of rock and soil along the Tinpiple-Banchare Dada road alignment. The purpose of the present study was to determine the... more
This paper describes about field study as well as laboratory test performed for the geotechnical properties of rock and soil along the Tinpiple-Banchare Dada road alignment. The purpose of the present study was to determine the geotechnical properties for both rocks and soils ...
FE modeling under plane stress condition is used to analyze the state of stress in and around the San Andreas Fault (SAF) System taking whole area of California. In this study we mainly focus on the state of stress at the general... more
FE modeling under plane stress condition is used to analyze the state of stress in and around the San Andreas Fault (SAF) System taking whole area of California. In this study we mainly focus on the state of stress at the general seismogenic depth of 12 km, imposing elastic ...
Research Interests: Geology and Seismology
The construction of the Tinpiple- Banchare Dada road was started at the beginning of the 1990 by Kathmandu Metropolitan City. The road starts from Tinpiple on the Kathmandu- Tirshuli-Dhunche road and plan to reach Banchare Dada... more
The construction of the Tinpiple- Banchare Dada road was started at the beginning of the 1990 by Kathmandu Metropolitan City. The road starts from Tinpiple on the Kathmandu- Tirshuli-Dhunche road and plan to reach Banchare Dada (Okharpauwa) through Simtar and Kagatigaun. It ...
FE modeling under plane stress condition was used to analyze the state of stress and failure in and around the San Andreas Fault (SAF) System. This study mainly focused on the state of stress at the general seismogenic depth of 12 km,... more
FE modeling under plane stress condition was used to analyze the state of stress and failure in and around the San Andreas Fault (SAF) System. This study mainly focused on the state of stress at the general seismogenic depth of 12 km, imposing elastic rheology. The purpose of the present study was to simulate the regional stress field, displacement vectors and failures. Series of calculations were performed with the parametrical variations of rock domain properties and were applied for the strong/weak SAF. The imposed boundary condition (fixed North American plate, Pacific plate motion along N 34° W vector up to northern terminus of the San Andreas faults and N 50° E vector motion for the subducting Gorda and Juan de Fuca plates) has simulated the present day regional σHmaxorientation and displacement vector comparable with the observed data. Failure analysis performed based on Byerlee’s law directly tests the strong SAF, and variation of physical parameters in the Mohr-Coulomb failure criterion was utilized to test relatively strong/weak SAF. Simulated results (stress, displacement vector, and failures) in the weak fault in relatively strong crust conditions had more or less reproduced comparable and theoretically correct results, allowed to favor weak fault in relatively strong crust. Key words: SAF, FE modeling, σHmax orientation, failure analysis.
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Research Interests:
This paper describes about field study as well as laboratory test performed for the geotechnical properties of rock and soil along the Tinpiple-Banchar e Dada road alignment. The purpose of the present study was to determine the... more
This paper describes about field study as well as laboratory test performed for the geotechnical properties of rock and soil along the Tinpiple-Banchar e Dada road alignment. The purpose of the present study was to determine the geotechnical properties for both rocks and soils along the road alignment. Detailed geotechnical soil/rock field study sheets were used to record geotechnical parameters in the field and to know the site condition. Dynamic cone penetration test was performed in the in situ soil. Laboratory test were performed for the classification of the soil, and to determine the optimum moisture content. Results reveal that most part of the road is aligned through the completely weathered sandstone, its residual soil (classified as SM) along with the gneisses. The results of the Dynamic Cone Penetration Test show that minimum CBR % varies from 18% at 10 cm depth to 2% at 58 cm. These values of the CBR % are considered good so no capping is required. The results of the com...
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Terraces are the geomorphic units once occupied by the rivers. When a river cuts down into its flood plain, the former alluvial surface is no longer flooded and is left as a more or less flat terrace above the new level of the river. If... more
Terraces are the geomorphic units once occupied by the rivers. When a river cuts down into its flood plain, the former alluvial surface is no longer flooded and is left as a more or less flat terrace above the new level of the river. If the downcutting resumes, a second pair of terrace may ...
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Research Interests:
Many interesting findings were obtained during the INDEPTH geophysical surveys but the results of these surveys were not sufficient to explore the deep crustal relations among the Himalayan Mega Thrust namely MCT, STD and GCT. In this... more
Many interesting findings were obtained during the INDEPTH geophysical surveys but the results of these surveys were not sufficient to explore the deep crustal relations among the Himalayan Mega Thrust namely MCT, STD and GCT. In this study, 2-D finite element method is used to analyze the state of stress and deep crustal relation between MCT, STD and GCT. Elasto-plastic, plane strain model constrained by the northward convergent displacement boundary condition is used to simulate the stress field. Modelling results reveal that thrust/fault geometry, their deep crustal relations and how do they terminate has effect on the stress field, displacement vector, shear stress and exhumation. The lateral variation of the stress orientation and surface exposure of fault/thrust and lithologic units may be the expression of the deep crustal relations between the major structures, their geometry and how do they terminate at the depth. So the along strike variation in the Himalaya may be the manifestation of structural geometry and their deep crustal relationships.
2D finite element modeling is used to analyze the state of stress in and around the San Andreas Fault System (SAFS) taking the whole area of California. In this study we focus on the state of stress at the general seismogenic depth of 12... more
2D finite element modeling is used to analyze the state of stress in and around the San Andreas Fault System (SAFS) taking the whole area of California. In this study we focus on the state of stress at the general seismogenic depth of 12 km, imposing elastic rheology. The purpose of the present study is to simulate the regional stress field and also to find the stress perturbation due to Big Bend and Garlock Fault. Although in nature there is lateral and vertical variation in rheology, our highly simplified domain properties had simulated results comparable with the observed data. Our imposed boundary condition (fixed North American plate, Pacific plate motion along N34W vector up to northern terminus of the San Andreas faults and N50E vector motion for the subducting Gorda plate) simulated the present day regional Hmax orientation and velocity vector. Simulated results show local effect on the stress field and displacement vector by the Big Bend and is further enhanced by the Garlock Fault, which may have significant impact on fault slip, stress, and hence the deformation in the surrounding region.
This paper deals with foundation characteristics of the soils of different parts of Nepal. Foundation characteristics of the soil depends upon the soil properties such as soil type, grading, liquid limit, plastic limit, density, cohesion,... more
This paper deals with foundation characteristics of the soils of different parts of Nepal. Foundation characteristics of the soil depends upon the soil properties such as soil type, grading, liquid limit, plastic limit, density, cohesion, compactness of the soil in the layer, friction angle etc. This paper deals with the multiple approaches carried out to find out foundation characteristics of the soil. In this study a total of 14 sites were selected. 2 sites were from the hilly region 2 from the inner Terai and 10 from the Terai. In each of the site two test sites were selected. In each test site Simplified Penetration Apparatus tests were carried out. This is the simple instrument designed for the shallow soil slope investigation. Here this instrument was used to characterize the subsurface soil horizons using the Nc number (the no. of blows required to penetrate the 10 cm depth). For each of the site two tests were carried out so that direct comparison can be done. Each site is accompanied by the auger test so that direct observation of the soil at depth of penetration can be done. Cross litholog of each site along with the Nc value was used to prepare the detailed subsurface soil horizons. Soil samples from different depths in each site were collected for laboratory test. Undisturbed soil samples were collected for the direct shear test and disturbed samples were collected for the soil classification, LL- PL test, density and other test. Bearing capacity of the soil thus obtained from the laboratory was compared with the soil type of the depth and the Nc value at that depth. From the study it was found that the Nc value depends upon the types of the soil and on the compactness of the soil. Once the standard value is obtained it can be used to determine the bearing capacity of the soil reducing the laboratory test.
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INDEPTH geophysical and geological observations imply that a partially molten mid crustal layer exists beneath southern Tibet. This partially molten layer has been produced by crustal thickening and behaves as a fluid on the time scale of... more
INDEPTH geophysical and geological observations imply that a partially molten mid crustal layer exists beneath southern Tibet. This partially molten layer has been produced by crustal thickening and behaves as a fluid on the time scale of Himalayan deformation. It is confined on the south by the structurally imbricated Indian crust underlying the Tethyan and High Himalaya and is underlain, apparently, by a stiff Indian mantle lid (Nelson et. al., 1996). Considering this partially molten middle crust and existing fault zones as plastic bodies and remaining crust as elastic body, a 2-D finite element elasto-plastic model is developed for the analysis of the stress field and displacement vectors. Young’s modulus, density, Poisson’s ratio, yield strength and strain hardening are used to constrain the physical properties of the layers (Table 1). Convergent displacement from the southern boundary is applied. Lower boundary is fixed vertically. The northern boundary is fixed horizontally but can move vertically. The upper boundary is free to move both horizontally and vertically (Fig.1). Series of calculations were done with the variation of the physical properties of different layers and displacement boundary conditions. 0.1 m, 1 m, and 10 m were chosen for the incremental displacement. If 20 mm/yr is considered as the present convergent rate of the Indian plate, 0.1 m increment can be considered for 5 yrs. The total output is cumulative for example 10 m total output can be considered as for 500 yrs at 0.1 m increment and so on. All the calculations were performed under 3 % volume change. Stress field do not vary so much on the increment rate, but the velocity vector varies. Finer increment produced more reasonable velocity vectors. Model results indicate that crustal strength variations have remarkable effect on the stress field and fault types. Reasonable and comparable stress fields (Fig. 2), velocity vector (Fig.3) and shear stress (Fig. 4) were obtained when pre-existing variations in crustal strength were considered. A stronger homogenous crust or a weaker heterogeneous crust did not produce comparable results. In general, model results show compressive state of stress in Himalaya and Tibet in the lower realm but the upper part in the Tibet shows tension. Magnitude of principal stresses increases with increase in displacement. The frontal part of the Himalaya also showed some tension and tensional stress was found near STDS and major fault also (Fig 2). The north Himalayan domes and normal faults in the Tibet are well simulated in our model (Fig.2). Shear stress is concentrated just north of the MCT ramp and on the MCT duplex (Fig.4). Material flow is toward the weak zone as shown by the velocity vectors (Fig. 3). Preliminary results of the simulation show that rock layer properties and boundary condition has strong effect on the stress and velocity vector. More detail calculations are needed to explore their effects in detail.
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2D FE modelling under plane strain condition is used to analyze the effect of physical properties on the state of stress along a Himalayan Section. In this study we focus on the state of stress, displacement vectors and shear stress... more
2D FE modelling under plane strain condition is used to analyze the effect of physical properties on the state of stress along a Himalayan Section. In this study we focus on the state of stress, displacement vectors and shear stress obtained by applying the convergent displacement boundary conditions, imposing elasto-plastic rheology. The purpose of the present study is to simulate the regional stress field, orientation of the displacement vector and shear stress to explore the relative role of physical properties of crust and partially molten middle crust. Our model results reveal that higher values of the Young's modulus, density, yield strength and strain hardening for the mafic lower crust and Indian crust and higher value of Poisson's ratio for the partially molten middle crust can produce the reasonable stress filed in the Himalaya and southern Tibet provided general and almost establish physical properties of the other layer and fault zone.
Finite Element (FE) modeling under plane stress condition is used to analyze the fault type variation with depth along and around the San Andreas Fault (SAF) zone. In this simulation elastic rheology was used and was thought justifiable... more
Finite Element (FE) modeling under plane stress condition is used to analyze the fault type variation with depth along and around the San Andreas Fault (SAF) zone. In this simulation elastic rheology was used and was thought justifiable as the variation in depth from 0.5 km to 20 km was considered. Series of calculations were performed with the variation in domain properties. Three types of models were created based on simple geological map of California, namely, 1) single domain model considering whole California as one homogeneous domain, 2) three domains model including the North American plate, Pacific plate, and SAF zone as separate domains, and 3) Four domains model including the three above plus the Garlock Fault zone. Mohr-Coulomb failure criterion and Byerlee’s law were used for the calculation of failure state. All the models were driven by displacement boundary condition imposing the fixed North American plate and Pacific plate motion along N34°W vector up to the northern terminus of SAF and N50°E vector motion for the subducting the Gorda and Juan de Fuca plates. Our simulated results revealed that as the depth increased, the fault types were generally normal, and at shallow depth greater strike slip and some thrust faults were formed. It is concluded that SAF may be terminated as normal fault at depth although the surface expression is clearly strike slip.
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FE modeling under plane stress condition was used to analyze the state of stress and failure in and around the San Andreas Fault (SAF) System. This study mainly focused on the state of stress at the general seismogenic depth of 12 km,... more
FE modeling under plane stress condition was used to analyze the state of stress and failure in and around the San Andreas Fault (SAF) System. This study mainly focused on the state of stress at the general seismogenic depth of 12 km, imposing elastic rheology. The purpose of the present study was to simulate the regional stress field, displacement vectors and failures. Series of calculations were performed with the parametrical variations of rock domain properties and were applied for the strong/weak SAF. The imposed boundary condition (fixed North American plate, Pacific plate motion
along N 34° W vector up to northern terminus of the San Andreas faults and N 50° E vector motion for the subducting Gorda and Juan de Fuca plates) has simulated the present day regional σHmax orientation and displacement vector comparable with the observed data. Failure analysis performed based on Byerlee’s law directly tests the strong SAF, and variation of physical parameters in the Mohr-Coulomb
failure criterion was utilized to test relatively strong/weak SAF. Simulated results (stress, displacement vector, and failures) in the weak fault in relatively strong crust conditions had more or less reproduced comparable and theoretically correct results, allowed to favor weak fault in relatively strong crust.
along N 34° W vector up to northern terminus of the San Andreas faults and N 50° E vector motion for the subducting Gorda and Juan de Fuca plates) has simulated the present day regional σHmax orientation and displacement vector comparable with the observed data. Failure analysis performed based on Byerlee’s law directly tests the strong SAF, and variation of physical parameters in the Mohr-Coulomb
failure criterion was utilized to test relatively strong/weak SAF. Simulated results (stress, displacement vector, and failures) in the weak fault in relatively strong crust conditions had more or less reproduced comparable and theoretically correct results, allowed to favor weak fault in relatively strong crust.
This paper describes about field study as well as laboratory test performed for the geotechnical properties of rock and soil along the Tinpiple-Banchare Dada road alignment. The purpose of the present study was to determine the... more
This paper describes about field study as well as laboratory test performed for the geotechnical properties of rock and soil along the Tinpiple-Banchare Dada road alignment. The purpose of the present study was to determine the geotechnical properties for both rocks and soils along the road alignment. Detailed geotechnical soil/rock field study sheets were used to record geotechnical parameters in the field and to know the site condition. Dynamic cone penetration test was performed in the in situ soil. Laboratory test were performed for the classification of the soil, and to determine the optimum moisture content. Results reveal that most part of the road is aligned through the completely weathered sandstone, its residual soil (classified as SM) along with the gneisses. The results of the Dynamic Cone Penetration Test show that minimum CBR % varies from 18% at 10 cm depth to 2% at 58 cm. These values of the CBR % are considered good so no capping is required. The results of the compaction test show that maximum dry density for most of the samples were obtained at 10-15 % optimum moisture content. The results of the joint analysis revealed that chainage 2+ 115, 2+475, 5+125 to 5+ 175 and 7+220 km has probability of lateral, lateral / central, central and central wedge failure respectively. Small landslides were initiated in upslope side due to road cutting and can be stabilized by simple bioengineering techniques. The results of this study are very important for the construction of a sound road and should be considered during the full phase construction of the road.
F E modeling under plane stress condition is used to analyze the state of stress in and around the San Andreas Fault (SAF) System taking whole area of California. In this study we mainly focus on the state of stress at the general... more
F E modeling under plane stress condition is used to analyze the state of stress in and around the San Andreas Fault (SAF) System taking whole area of California. In this study we mainly focus on the state of stress at the general seismogenic depth of 12 km, imposing elastic rheology. The purpose of the present study is to simulate the regional stress field, displacement vectors and failures. Stress perturbation due to major fault, its geometry and major branches are analyzed. Depthwise variation from 20 km to 0.5 km is considered for the fault type analysis. Series of calculations are performed with the parametrical variations of domain properties and are applied for the strong/weak SAF. All the simulated results are finally utilized for the implication of present day plate kinematics. Although in nature there is lateral and vertical variation in rheology within single domain and different domains (not considered in this study), our simulated results are comparable with the observed data. The imposed boundary condition (fixed North American plate, Pacific plate motion along N34°W vector up to northern terminus of the San Andreas faults and N50°E vector motion for the subducting Gorda and Juan de Fuca plates) had simulated the present day regional SigmaHmax orientation and displacement vector. Simulated results show some local effect on the stress field and displacement vector by the main strand of the fault and probably its geometry and branch (Garlock Fault). Probably the low angle SigmaHmax orientation to the strike of the SAF system in the South California (although there are some high angle SigmaHmax orientation in southeastern California) compare to the central and northern California is due to the big bend and the Garlock Fault. This modeling had also beautifully simulated the left lateral strike slip movement on the Garlock Fault. Failure analysis performed based on Byerlee’s law directly test the strong SAF and variation of physical parameters in the Mohr-Coulomb failure criterion is utilized to test relatively strong/weak SAF. Our simulated results (like stress, displacement vector, and failures) in the weak fault in relatively strong crust conditions has more or less reproduced comparable and theoretically correct results, allowed us to favor weak fault in relatively strong crust. Depthwise variation of the fault type revel that as the depth increases, the fault types are generally normal and shallow depth gives more strike slip and thrust fault. In conclusion that SAF may terminate as a normal fault at the depth.
The Tinpiple-Banchare Dada road is located northwest of the Kathmandu valley. Since the area is a mountainous terrain consisting of varieties of slopes, development activities may be threatened by landslide related phenomena. Recently,... more
The Tinpiple-Banchare Dada road is located northwest of the Kathmandu valley. Since the area is a mountainous terrain consisting of varieties of slopes, development activities may be threatened by landslide related phenomena. Recently, Kathmandu Metropolitan City (KMC) and Ministry of Local Development are jointly constructing the access road (Tinpiple-Banchare Dada Road) for the mobilization of the solid wastes collected from the KMC. It is, therefore, desirable to have engineering geological studies along the road alignment. This paper describes the methodology used in preparing the engineering geological map along the road. The purpose of the present study was to prepare an engineering geological map along the road alignment and to determine the geotechnical properties for both rocks and soils. For these purposes, the required attributes for engineering geological studies were identified and are mapped in the field. Soil and rock samples were analyzed for different engineering parameters. Results reveal that the most part of the road is aligned through the completely weathered sandstone, its residual soil along with the gneisses. The result reveals that areas with 3-6 meter thick soil may be hazardous in terms of landslides and should be avoided, if possible.
The Himalaya is the largest, highest and most active mountains on the globe, and is still very actively changing its mountain topography and environment. The mountain range exhibits distinct zonal arrangements of geology, geomorphology,... more
The Himalaya is the largest, highest and most active mountains on the globe, and is still very actively changing its mountain topography and environment. The mountain range exhibits distinct zonal arrangements of geology, geomorphology, and climate. Consequently, a variety of natural hazards occurs in this mountain range and they are also zonally arranged along the range. Thus, the Himalaya is the best laboratory to study nature and natural hazards. We published the Guidebook for Himalayan Trekkers, Series No.1,?gGeology and Natural Hazards along the Kaligandaki Valley, Western Nepal?h in 2005 (Upreti and Yoshida, Special Publication No.1 of the Department of Geology, Trichandra Campus, Tribhuvan University, Kathmandu). The series No.2, ?gNatural Environment along the Everest Trekking Course, Eastern Nepal?h is under the process of publication, and a provisional Japanese guidebook, ?hGeology and Natural Hazards along the Dudhkoshi Valley, Everest Area?h was published last year (Yoshida et al., 2007, GRG/GIGE Miscl. Pub. 18, Field Science Publishers, Hashimoto). The field program for the guidebook series No3, ?gGeology and Natural Hazards along the Langtang Valley, Central Nepal?h starts this year. Successive numbers of the series are planned for the area surrounding Kathmandu, the Tansen to Lumbini route, the Maleku area, and so on, to cover important areas in the Nepal Himalaya. The guidebooks may contribute to help Himalayan trekkers to become familiar with the nature of Himalaya. Similarly, the guidebooks will help international scientists, teachers, students, and citizens to get general information of natural environment specifically of geology and natural hazards in the Himalaya and to be inclined to visit the Nepal Himalaya to conduct eco-trekking. The guidebooks are also expected to be useful to local people and local governmental officers to understand natural environment on which their lives rely. Some of the above areas, especially the Everest (1200km2 of territorial dimensions), Annapurna (8200km2), and Langtang (2000km2) areas are considered suitable as the UNESCO Geopark. We will start to make effort to apply for the registration of these areas as the Geopark. These areas are central of trekking tourism in Nepal, and are very appropriate for the study of natural environment of the Himalaya. National park offices have published several leaflets on natural environment including botany, zoology, and geosciences for visitors to study. Our guidebook series mentioned above will sure to enhance people?fs education on natural environment. The registration of these areas as the UNESCO Geopark will sure to be useful for the welfare of local communities and people, as well as all Nepalese people. We plan to make up effective secretarial centre and loose associations of related bodies including governmental agencies, foundations, business unions, museums, etc. The secretarial centre will be the Faculty of Science, Tribhuvan University.
२०१२ मार्च ११ तारिखमा झन्डै साढे ५ वर्षको जापान बसाइपछि नेपाल फर्केको छु, हरेक भेटघाटमा मलाई सोधिने प्रश्न एउटै हुन्छ- पत्तो कति ल्याइस्? जापानबाट फर्केको चानचुन अढाइ वर्ष भयो। अहिलेसम्म पनि यो प्रश्नको बहार भइ नै रहेको छ। नेपालमा... more
२०१२ मार्च ११ तारिखमा झन्डै साढे ५ वर्षको जापान बसाइपछि नेपाल फर्केको छु, हरेक भेटघाटमा मलाई सोधिने प्रश्न एउटै हुन्छ- पत्तो कति ल्याइस्?
जापानबाट फर्केको चानचुन अढाइ वर्ष भयो। अहिलेसम्म पनि यो प्रश्नको बहार भइ नै रहेको छ। नेपालमा मान्छेको चेतमा पैसाभन्दा अरु कुनै कुरा छजस्तो लाग्दैन। ५, ७ वर्षअगाडि १ कोठामा भातखाट गर्नेहरु कुनै व्यापार व्यवसाय नगरी काठमाडौंमा तीनतले, चारतले घरको मालिक भएका रहेछन्। हरेकको कम्तीमा ४ आना जग्गामा घर छ। सानका साथ १५ लाख आनामा किनेको र घर बनाउँदा ४० लाखको हाराहारीमा खर्च भयो भन्छन्। ठाडो हिसाबले पनि १ करोडको हिसाब आउँछ। ताज्जुब लाग्छ, कसरी ५, ७ वर्षमा यत्रो पैसा कमाइ भयो?
प्रश्न सोध्नेहरुमा निजामती कर्मचारीका खरदारदेखि सहसचिवसम्मका मानिस अनि अहिले ल्याण्ड डेभलोपर भनिने ज. द. (जग्गा दलाल) हरु छन्। ५, ७ वर्षअगाडि अहिलेको खरदार बेरोजगार थिए, अनि अहिलेको अफिसर, या त खरदार या त नासु थियो। कोहीकोही उति बेलामै अफिसर भएकाहरु या त अफिसर नै रहेछन्, या त उपसचिव, सहसचिव। कुरो आउँछ, ५, ७ वर्षमा परिवार पालेर डेरा बसेर कम्तीमा १ करोडको जेथो कसरी बन्यो?
म सन् २००६ को अक्टोबरमा जापान गएको हुँ। गएको दिनदेखि फर्किनु अघिल्लो दिनसम्म सरदर १ लाख ५० हजार रुपैयाँ मासिकको छात्रवृत्ति पाउँथे, र त पत्तो बनाउन सकिन भने यहाँ कसरी त्यत्रो पत्तो कमाइ भयो? खर्चको कुरा गर्ने हो भने महंगी यती साह्रो बढेछ कि जापान र यहाँ खासै फरक लागेन। कर्मचारीको हकमा भ्रष्टाचार नगरी अरु कुनै उपाय म कल्पना गर्न सक्दिन। ज. द. हरुले आयकर तिरेनन् या त नेपालमा आयकरको नियम नै छैन।
यो ५, ७ वर्षमा मान्छेहरु यति निच भैसकेछन् कि आजसम्म कसैले के पढिस्, कति पढिस् भनेर सोधेकै छैनन् जबकि म छात्रवृत्ति पाएर पिएचडी गर्न गएको सबैलाई थाहा छ। यही स्थिति रहिरहने हो भने पैसा कमाउन बन्धक बनाउनेलाई पनि कानुनी रुपमा छुट दिए के फरक पर्ला र? आखिर हरेकको उद्देश्य एकै रहेछ, पत्तो कमाउने। दैनिक नेपालको समाचार हेर्थे बन्धक बनाउने, मार्ने, पैसा असुलीका समाचार हुन्थे। मनमा लाग्थ्यो, यो के भएको हो नेपालमा। मान्छे कति पापी भएका हुन्। तर यहाँ आएपछि यस्तो लाग्यो कि सरकार नै यो गराउँदैछ। हैन भने कसले कसरी कति कमायो, यसको हिसाब सरकारले खोज्नु जरुरी छ।
यदि यही स्थिति रहने हो भने धनी बन्ने होडमा अझै कति बन्धकका, हत्याका अपराधहरु यो देशमा हुने हुन्? जंगलराज, लुट, हत्या, आतंक कहिले सम्म रोकिन्छ र जनताले राहतको सास फेर्ने? पत्तो कति ल्याइस् भन्नेहरुले कति पढेर आइस् भनुन् भन्ने मेरो कामना कहिले पूरा होला? मैले साढे ५ वर्षमा ५ वटा पत्तो कमाएँ। एउटा मास्टर डिग्री, एउटा पिएचडी डिग्री, एउटा कनिकुथी जापानी भाषा बोल्नसक्छ भन्ने प्रमाणपत्र अनि एउटा पिएचडी डिग्रीमा पाएको डिरेक्टर अवार्ड र आफूलाई निरोगी बनाउँ न त भन्दाभन्दै सिकेको कराँतेको ब्ल्याक बेल्टको प्रमाणपत्र। सानका साथ मैले यति नै पाँच पत्तो कमाएँ भन्ने दिन कहिले आउला?
जापानबाट फर्केको चानचुन अढाइ वर्ष भयो। अहिलेसम्म पनि यो प्रश्नको बहार भइ नै रहेको छ। नेपालमा मान्छेको चेतमा पैसाभन्दा अरु कुनै कुरा छजस्तो लाग्दैन। ५, ७ वर्षअगाडि १ कोठामा भातखाट गर्नेहरु कुनै व्यापार व्यवसाय नगरी काठमाडौंमा तीनतले, चारतले घरको मालिक भएका रहेछन्। हरेकको कम्तीमा ४ आना जग्गामा घर छ। सानका साथ १५ लाख आनामा किनेको र घर बनाउँदा ४० लाखको हाराहारीमा खर्च भयो भन्छन्। ठाडो हिसाबले पनि १ करोडको हिसाब आउँछ। ताज्जुब लाग्छ, कसरी ५, ७ वर्षमा यत्रो पैसा कमाइ भयो?
प्रश्न सोध्नेहरुमा निजामती कर्मचारीका खरदारदेखि सहसचिवसम्मका मानिस अनि अहिले ल्याण्ड डेभलोपर भनिने ज. द. (जग्गा दलाल) हरु छन्। ५, ७ वर्षअगाडि अहिलेको खरदार बेरोजगार थिए, अनि अहिलेको अफिसर, या त खरदार या त नासु थियो। कोहीकोही उति बेलामै अफिसर भएकाहरु या त अफिसर नै रहेछन्, या त उपसचिव, सहसचिव। कुरो आउँछ, ५, ७ वर्षमा परिवार पालेर डेरा बसेर कम्तीमा १ करोडको जेथो कसरी बन्यो?
म सन् २००६ को अक्टोबरमा जापान गएको हुँ। गएको दिनदेखि फर्किनु अघिल्लो दिनसम्म सरदर १ लाख ५० हजार रुपैयाँ मासिकको छात्रवृत्ति पाउँथे, र त पत्तो बनाउन सकिन भने यहाँ कसरी त्यत्रो पत्तो कमाइ भयो? खर्चको कुरा गर्ने हो भने महंगी यती साह्रो बढेछ कि जापान र यहाँ खासै फरक लागेन। कर्मचारीको हकमा भ्रष्टाचार नगरी अरु कुनै उपाय म कल्पना गर्न सक्दिन। ज. द. हरुले आयकर तिरेनन् या त नेपालमा आयकरको नियम नै छैन।
यो ५, ७ वर्षमा मान्छेहरु यति निच भैसकेछन् कि आजसम्म कसैले के पढिस्, कति पढिस् भनेर सोधेकै छैनन् जबकि म छात्रवृत्ति पाएर पिएचडी गर्न गएको सबैलाई थाहा छ। यही स्थिति रहिरहने हो भने पैसा कमाउन बन्धक बनाउनेलाई पनि कानुनी रुपमा छुट दिए के फरक पर्ला र? आखिर हरेकको उद्देश्य एकै रहेछ, पत्तो कमाउने। दैनिक नेपालको समाचार हेर्थे बन्धक बनाउने, मार्ने, पैसा असुलीका समाचार हुन्थे। मनमा लाग्थ्यो, यो के भएको हो नेपालमा। मान्छे कति पापी भएका हुन्। तर यहाँ आएपछि यस्तो लाग्यो कि सरकार नै यो गराउँदैछ। हैन भने कसले कसरी कति कमायो, यसको हिसाब सरकारले खोज्नु जरुरी छ।
यदि यही स्थिति रहने हो भने धनी बन्ने होडमा अझै कति बन्धकका, हत्याका अपराधहरु यो देशमा हुने हुन्? जंगलराज, लुट, हत्या, आतंक कहिले सम्म रोकिन्छ र जनताले राहतको सास फेर्ने? पत्तो कति ल्याइस् भन्नेहरुले कति पढेर आइस् भनुन् भन्ने मेरो कामना कहिले पूरा होला? मैले साढे ५ वर्षमा ५ वटा पत्तो कमाएँ। एउटा मास्टर डिग्री, एउटा पिएचडी डिग्री, एउटा कनिकुथी जापानी भाषा बोल्नसक्छ भन्ने प्रमाणपत्र अनि एउटा पिएचडी डिग्रीमा पाएको डिरेक्टर अवार्ड र आफूलाई निरोगी बनाउँ न त भन्दाभन्दै सिकेको कराँतेको ब्ल्याक बेल्टको प्रमाणपत्र। सानका साथ मैले यति नै पाँच पत्तो कमाएँ भन्ने दिन कहिले आउला?