111 Using Near Surface Geophysics to Investigate Geological Problems (Posters)

Abstracts are requested that use geophysics to solve a wide variety of near surface geological problems including hydrology, karst, environmental, engineering, archaeological and geological mapping.

Monday, 20 October 2025
8:00 AM - 5:30 PM
HBGCC, Hall 1

An Integrated Method Used for Findings of Geotechnical Site Characterization: A Case Study of Arun River Basin, Nepal

Paper number: 111-5
Program: Technical Sessions
Time: 8:00 AM – 8:00 AM

Authors

Abstract

Geotechnical investigation is crucial to determine engineering properties of rock & soil. It is commonly carried out during foundation design & engineering construction. Arun valley lies in the northeastern part of Nepal which is also the deepest valley of the world. Arun River is one of the tributary of Koshi River where large hydropower are under construction. Upper Arun Hydropower Project is one of the mega hydro project that is going to be constructed in this river basin. Detailed geological & geotechnical study was carried out to implement this project. Geological mapping was conceded as initial stage to know the surface geology & rock type. In this project area, both direct & indirect method has been adopted for geotechnical investigation to know subsurface geology. Geophysical method like ERT, SRT, MASW etc. has been adopted as indirect method of investigation while drilling has been conducted to find out the strata, weak zone & bedrock. Televiewer test was carried out for conducting borehole scanning under dry condition collecting picture covering inclination, azimuth, aperture etc. of fractures zones with a fluid ingress above water level. Geologically the project area lies in lesser himalayan zone of sub-division of Nepal Himalaya. The major rock type found are Quartzite, amphibolite, marble, schistose gneiss, augen gneiss & banded gneiss. The main geological structure present is MCT.  Rock mass rating (RMR) & Q value was calculated & correlated each other to determine the rock mass quality.

Geological Society of America Abstracts with Programs. Vol. 57, No. 6

doi: 10.1130/abs/2025AM-413990

© Copyright 2025 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.