Dr. Matrika Prasad Koirala | Tribhuvan University (original) (raw)

Uploads

Books by Dr. Matrika Prasad Koirala

JAMGHAT September, 2022. Issue 7, 2022

A Publication of Nepalese Community of Northwest America (British Columbia, Canada, Washington an... 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.

A Publication of Nepalese Students' Association In Japan

A Publication of Nepalese Students' Association in Japan

F E modeling under plane stress condition is used to analyze the state of stress in and around th... 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, Nuw... 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.

Papers by Dr. Matrika Prasad Koirala

Annual Meeting of the Geological Society of Japan, 2011

Himalayan Journal of Sciences, 2008

Terraces are the geomorphic units once occupied by the rivers. When a river cuts down into its fl... 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 ...

Journal of Nepal Geological Society, 2011

This paper deals with foundation characteristics of the soils of different parts of Nepal. In thi... 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...

Journal of Nepal Geological Society, 2007

Journal of Mountain Science, 2010

NEPAL GEOLOGICAL SOCIETY

Page 70. 56 Sixth Nepal Geological Congress Elasto-plastic finite element modeling along the proj... more 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 ...

FE modeling under plane stress condition is used to analyze the state of stress in and around the... 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 ...

BULLETIN-COLLEGE OF …

The construction of the Tinpiple- Banchare Dada road was started at the beginning of the 1990 by ... 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 ...

Academic Journals, Aug 31, 2009

FE modeling under plane stress condition was used to analyze the state of stress and failure in a... 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.

This paper describes about field study as well as laboratory test performed for the geotechnical ... 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...

nepjol.info

JAMGHAT September, 2022. Issue 7, 2022

A Publication of Nepalese Students' Association In Japan

A Publication of Nepalese Students' Association in Japan

Annual Meeting of the Geological Society of Japan, 2011

Himalayan Journal of Sciences, 2008

Journal of Nepal Geological Society, 2011

Journal of Nepal Geological Society, 2007

Journal of Mountain Science, 2010

NEPAL GEOLOGICAL SOCIETY

BULLETIN-COLLEGE OF …

Academic Journals, Aug 31, 2009

nepjol.info

Himalayan Journal of Sciences, 2008

Many interesting findings were obtained during the INDEPTH geophysical surveys but the results of... 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 F... 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. Founda... 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.

२०१२ मार्च ११ तारिखमा झन्डै साढे ५ वर्षको जापान बसाइपछि नेपाल फर्केको छु, हरेक भेटघाटमा मलाई सोधि... 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?