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Collaborating Authors
Nepal
In 2015, a magnitude 7.8 earthquake hit Nepal, claiming about 9000 human lives and leaving many homeless. Yet, even larger earthquakes are expected to come in the future. The aim of this project is to test the feasibility of Earthquake Early Warning (EEW) in central Nepal by establishing a low-cost real-time earthquake monitoring system based on OpenEEW technology.
The main goal of the project is to test a low-cost, real-time earthquake monitoring system in central Nepal, in a densely populated region between the cities of Pokhara and Kathmandu. If successful, the system should be transformed into an earthquake early warning system in Nepal. We want to build local expertise to ensure the continued operation of the network and help our local partners secure finances for the continuation of the system.
- Asia > Nepal > Province No. 3 > Kathmandu (0.33)
- Asia > Nepal > Gandaki Pradesh > Pokhara (0.27)
- North America > United States > Oregon (0.18)
Tribhuvan University SEG Student Chapter was founded in the premises of Tri-Chandra Multiple Campus, on August 15, 2018. Soon after the devastating 2015 Gorkha Earthquake, the Chapter came out as a platform for the students of Geosciences to convey knowledge and make people aware of earthquake hazards and risk mitigation. In 2020 the Chapter, with grants and help from SEG, organized an Outreach Program titled "Earthquake Preparedness through Awareness for School Children." Students studying Geology at the Tri-Chandra Multiple Campus are an integral part of this Student Chapter. We collaborate with faculty members and other organizations to make humanitarian contributions in geology, geophysics and geosciences.
- Education (0.62)
- Health & Medicine > Therapeutic Area > Infections and Infectious Diseases (0.34)
- Health & Medicine > Epidemiology (0.34)
Challenges Associated with the Construction of Vertical and Inclined Shafts in the Himalayan Region
Katuwal, Tek Bahadur (Norwegian University of Science and Technology, Norway / Tribhuvan University, IOE, Pashchimanchal Campus, Nepal) | Panthi, Krishna Kanta (Norwegian University of Science and Technology, Norway) | Basnet, Chhatra Bahadur (Tribhuvan University, IOE, Pashchimanchal Campus, Nepal)
ABSTRACT: In the Nepal Himalayas, hydropower projects having an installed capacity of over 10 MW usually consist of underground waterways. Most of these underground waterways consist of vertical or inclined pressure shafts, which are part of the headrace system of a hydropower project. Excavation of these shafts requires special techniques, and the performance is dependent on the quality of rock mass. Therefore, the selection of an efficient construction method for shaft excavation is most challenging work. This manuscript evaluates the challenges associated with the construction of shafts for three hydropower projects in the Nepal Himalayas. The achieved construction progress of each method is compared with actual geological conditions. It is concluded that the major challenges associated with the excavation of pressure shafts through the Himalayan rock mass conditions are frequent overbreak, water inflow, debris flow, difficulties in surveying and control of shaft alignment, ventilation, poor visibility, and pilot hole deviation. INTRODUCTION Natural events such as rock-soil failure, high rainfall, landslide, tunnel collapses, etc. cause challenges associated with the development of hydropower projects. Appropriate and viable underground excavation methods should be used to address these problems (Panthi 2006). In hydropower projects, unlined or lined underground pressure shafts are constructed either vertically or inclined to carry water from the headrace tunnel to the powerhouse. In the Nepal Himalaya, most of the hydropower plants with installed capacities over 10 MW consist of underground pressure shafts as penstock water conveyance systems. The construction of shaft with length (depth) greater than 200 m is a challenging task due to uncertainties in the underground excavation (Sunuwar 2016). These uncertainties are categorized as geological factors associated to weak rock mass quality, high weathering, faulting and fracturing of rock mass, rock stress, and groundwater effect; and non-geological uncertainties associated to the level of skill, expertise, and the technology in use. The stepwise geological investigation is crucial to minimize the uncertainties in underground excavation work (Panthi 2006 and Panthi 2007). In this manuscript, three shafts of hydropower projects from the Nepal are selected to present the case histories of the shaft excavation and challenges faced during the excavation of these shafts. In addition, applied remedial measures are also discussed.
- Geology > Geological Subdiscipline > Geomechanics (0.49)
- Geology > Rock Type (0.47)
- Management > Professionalism, Training, and Education > Communities of practice (0.49)
- Data Science & Engineering Analytics > Information Management and Systems > Knowledge management (0.49)
- Reservoir Description and Dynamics > Reservoir Characterization > Reservoir geomechanics (0.35)
- Reservoir Description and Dynamics > Reservoir Characterization > Geologic modeling (0.35)
Stability Issues Associated with the Construction of Underground Caverns of Super Dordi Hydropower Project, Nepal
Adhikari, Sailesh (Norwegian University of Science and Technology, Norway / Tribhuvan University, IOE, Pashchimanchal Campus, Nepal) | Panthi, Krishna Kanta (Norwegian University of Science and Technology, Norway) | Basnet, Chhatra Bahadur (Tribhuvan University, IOE, Pashchimanchal Campus, Nepal)
ABSTRACT: The rock mass is heterogeneous and makes underground space construction a challenge to engineers. The rock formation, mineralogical composition, degree of schistosity, and weathering, are the major factors that determine the stability condition and rock support requirements. This manuscript deals with the stability situation of the underground settling basin caverns of Super Dordi Hydropower Project (SDHP) in Lamjung district of Nepal which is located at the lower boundary of the Higher Himalayan rock formation. The two parallel underground settling basins are 120m long and have an approximate cross-sectional area of 113 sq. m. The manuscript further discusses geological and rock mass quality conditions and evaluates the stability of the underground settling basins using 2D numerical modeling. The outcomes of the analysis presented in the manuscript have been helpful for the optimization of applied rock support. INTRODUCTION Underground caverns are generally used for constructing civil engineering structures, storage purposes (food, nuclear waste, etc.), performing laboratory work, etc. In hydropower engineering, the caverns are mainly used for the construction of powerhouses and settling basins. The challenging factors for the construction of underground caverns are geological investigations, stability analysis, and support design. It should be followed by the excavation method and the redesign of the rock support based on construction observation (Tezuka & Seoka 2003). The major stability problems in underground caverns are block falls, rock bursting, rock spalling, and rock squeezing. The primary factor influencing these stability problems is associated with rock mass quality. The major factors that influence the rock mass quality in the underground opening are rock mass strength, rock deformability, strength anisotropy, discontinuities in the rock mass, and degree of weathering (Panthi 2006). Some of the other stability problems are linked to water inflow and rock swelling. Rock bursts in the underground cavern have strong correlations with rock mass properties, excavation method and speed, and depth where the underground structures are located (Lee et al. 2004). A case study on the large underground powerhouse with a 34m span and 88.7 m height showed that rock fracturing and spalling appeared quickly after the excavation and continued to develop with the advancement of the working face (Liu et al. 2017). Squeezing in the caverns occurs due to weak rock mass, high overburden pressure, and large radius/span of the underground openings (Dwivedi et al. 2014). Providing suitable and optimized support can overcome the squeezing problems in the tunnels (Romero et al. 2007). The large-scale study of the tunnel site including the topography effect, induced stresses, and various other parameters can be done by numerical modeling. Numerical modeling is the tool to study/predict the spalling and rock burst in underground structures (Li et al. 2018, Manouchehrian & Cai 2018).
- Energy > Renewable > Hydroelectric (1.00)
- Energy > Power Industry > Utilities (1.00)
- Energy > Oil & Gas > Upstream (1.00)
Difficult Ground Conditions Demand for an Observational Approach for a Powerhouse Cavern in the Himalayas
Thermann, Karsten (Tractebel Engineering GmbH, Germany) | Shilpakar, Raja Bhai (Tanahu Hydropower Ltd, NEA, Nepal) | Parajuli, Bibash (PowerChina Chengdu Engineering Co. Ltd, China) | Christakis, Eirinaios (Tractebel Engineering GmbH, Germany)
ABSTRACT: The powerhouse cavern excavation for Tanahu Hydropower Project (140MW), in Nepal, was successfully completed in July 2022. The site is geologically located in the Lesser Himalayan Zone. During cavern excavation, moderately to highly foliated Slate with phyllitic Slate intercalations and localised sheared zones were encountered. To cope with difficult ground conditions, the design of rock support was not only based on 3D-modelling but rather adopted an observational approach. Thus, during excavation a thorough monitoring system was implemented consisting of multi-point borehole extensometers, load cells, convergence stations and piezometers. Data collection and evaluation of results were conducted on a daily basis during the whole excavation process. Aiming to mitigate occurring deformations during the excavation stage, the rock support measures were modified accordingly. Furthermore, to control overstressing, loads from pre-stressed double-corrosion protected anchors required stress release. The timely response to monitoring results was of paramount importance for the successful excavation of the powerhouse cavern. INTRODUCTION (GENERAL SITE GEOLOGY) The powerhouse cavern of Tanahu Hydropower Project (height 45m, width 22m, length 89m) has been entirely excavated in the Slates of Benighat series, a sub-unit of Upper Nawakot Group which is part of the Lesser Himalayan Sequence. The formation consists of dark bluish grey to black slightly to moderately weathered, highly cleaved Slates and Phyllites. The excavation stage revealed weak to moderately strong, thin to thinly foliated fresh Slates. The excavated formation is mainly argillaceous with subordinate bands of siliceous fine-grained Quartzite, as well as localised intercalations of shear zones. The majority of shear zones exists parallel or sub-parallel to the foliation, with a gradually increasing thickness (between 10mm and 80cm), from the North to South end-wall of the cavern. Areas of very poor rock-mass with distinct cleavage and thin foliation/lamination were advanced by mechanical means. The moderately strong rock-mass (UCS: 20-60 MPa) and its high degree of anisotropy (Tsidzi & Kwami 1990) in conjunction with weak interlayers and the aforementioned shear zones resulted to a challenging excavation process during which large deformation and excessive loads in anchors (higher than their design load) were encountered.
- Geology > Rock Type > Metamorphic Rock > Slate (1.00)
- Geology > Geological Subdiscipline > Geomechanics (0.96)
- Geology > Structural Geology > Tectonics > Compressional Tectonics > Fold and Thrust Belt (0.50)
ABSTRACT: Stability of a cut-slope at the headworks area of the hydropower projects is very important for smooth operation of hydropower plant. Underestimation during construction period may bring a catastrophic consequence. This manuscript presents overall assessment results of the rock cut slope excavated to accommodate two settling basins of Seti Khola Hydropower Project (22 MW) located at Lekhnath, Kaski, Nepal. The height of the cut slope is about 50 m and is among the most challenging part of the construction work. The cut slope is excavated in a highly schistose and deformed phyllite with interbedding of metasandstone layers. The evaluations are made on the overall rock mass and discontinuity characteristics. The results of detailed stability assessment using software program SLIDE in consideration with both normal and seismic loading conditions are presented. Final rock support measures are proposed to ascertain long-term stability of the cut-slope. INTRODUCTION Stability of rock slope is dependent on the slope topography, the orientation of discontinuity planes, the shear strength of discontinuities, groundwater and stress conditions, and the seismic acceleration magnitude. The factors that influence the shear strength of the discontinuities are the frictional properties associated to roughness, and infilling condition of the main failure plane and the presence of groundwater (Panthi, 2021). In addition, the geometry of the cut slope and seismic acceleration caused by earthquakes (Wyllie and Mah, 2004) or vibration caused by blasting also influence in the overall stability of a cut-slope (Panthi and Nilsen, 2006). According to Nilsen and Palmstørm (2000) the rock slope stability assessment typically involves a three-step procedure consisting of 1) Definition of potential problem, 2) Quantification of input parameters and, 3) Calculation of stability. In the Himalaya, slope cutting in highly deformable and fractured rock mass is one of the challenging tasks in the infrastructure development activities such as road cuts, cut slopes for hydropower projects, portals to the tunnels and so forth (Panthi, 2006). The failure criterion in such slopes is hard to define as the failure is governed by the joints, fractures, frequent shear bands, and highly schistose and deformed rock mass which may act as soil like material. Similar complexity is experienced at the settling basin cut slope in Seti Khola Hydropower Project in Nepal. Cracks at the slopes are developed with the progressive excavation going from top to the bottom of slope. This manuscript evaluates the cut slope in terms of geological conditions, slope geometry, rock mass and discontinuity properties and evaluates the overall stability condition of the cut slope.
Improving potable water access using electrical resistivity tomography and community engagement to identify groundwater potential zones in the village of Phortse, Sagarmatha National Park (Khumbu), Nepal
Cobb, Chasalin T. (Environment, Geology, and Natural Resources, Ball State University) | Nicholson, Kirsten (Environment, Geology, and Natural Resources, Ball State University) | Gruver, Joshua (Environment, Geology, and Natural Resources, Ball State University) | Acharya, Smrita (Environment, Geology, and Natural Resources, Ball State University) | Baniya, Seamon (Environmental Science and Engineering, Kathmandu University) | Hall, Steven (Political Science, Ball State University) | Han, Bangshuai (Environment, Geology, and Natural Resources, Ball State University) | Hayes, Emily (Environment, Geology, and Natural Resources, Ball State University) | Neumann, Klaus (Environment, Geology, and Natural Resources, Ball State University) | Nishikawa, Misa (Political Science, Ball State University) | Pandey, Anusha (Environmental Science and Engineering, Kathmandu University) | Sharma, Subodh (Environmental Science and Engineering, Kathmandu University) | Sherpa, Lakpa (Action for Nepal) | Subedi, Esan (Environmental Science and Engineering, Kathmandu University)
Increasing tourism and effects of climate change are the two highest threats to conservation in the Sagarmatha National Park (SNP), Nepal, and have extraordinary impacts on drinking water quality and availability for its indigenous and local communities. Aquifers, though not well studied at high altitudes, could be a potential source of supplementary potable water. In a first-ever attempt in the region, an Electrical Resistivity Tomography (ERT) survey was conducted in the SNP (locally referred to as Khumbu) to identify anomalies in the subsurface that correspond with potential groundwater zones. Methodology was adapted and modified with each trial due to the terraced terrain and varied elevation levels in the village. Advanced Geosciences Incorporated (AGI) EarthImager subsurface maps were produced from the ERT readings, and several low-resistivity anomalies were identified in the villages of Phortse, Khumjung, and Kundee. When preliminary findings are confirmed, these villages will have the potential to utilize this groundwater zone to supplement their current diminishing water resources. Given current climate change trends and the surge of glacial melting in this rugged and remote region, the future of water management in the SNP will benefit from having access to multiple water sources.
- Geophysics > Electromagnetic Surveying (0.62)
- Geophysics > Borehole Geophysics (0.62)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Open hole/cased hole log analysis (0.62)
- Reservoir Description and Dynamics > Formation Evaluation & Management > Cross-well tomography (0.62)
- Health, Safety, Environment & Sustainability > Environment > Waste management (0.53)
- Health, Safety, Environment & Sustainability > Sustainability/Social Responsibility > Community outreach (0.41)
Professors Kirsten Nicholson and Klaus Neumann lead a Geoscientists without Borders (GWB) project to find safe drinking water for two communities in the Sagarmatha National Park, Nepal. In this episode, you hear exclusively from Kirsten and Klaus as they take you on a journey from discovering the need for this project to what they hope they will contribute to these communities. This is a powerful example of the significant contribution geoscientists can make when focused on a meaningful project for a local community.
During the fieldwork, the project team visited the region between the cities of Pokhara and Kathmandu (Lesser Himalaya), and two valleys around the Annapurna massif – the Jomsom and Manang valley. During this phase of the project, the work continues seismic observations in the region and a close watch on connectivity of the stations. The project lead (PI) is also talking to their Nepali partners about the project's continuation, during which the PI would extend the seismic network in the whole country to eventually start delivering public alerts and notifications.
- Asia > Nepal > Province No. 3 > Kathmandu (0.34)
- Asia > Nepal > Gandaki Pradesh > Pokhara (0.34)