3D modeling of the fracture zones to decipher foundation level at Barethi Super Thermal Power Project, Madhya Pradesh, India

DOI

10.2991/rare-16.2016.36How to use a DOI?

Keywords

BGM; BGC; IDW, 3D modeling; NTPC

Abstract

The proposed 6x 660 MW Super Thermal Power Project is located near village Sandni and Barethi in Rajnagar Tehsil of Chhatarpur district, Madhya Pradesh. The terrain belongs to Bundelkhand Granite Massif (BGM) comprising a variety of medium to coarse grained granites. The Project site is mainly covered with soil/overburden material barring a few sporadic outcrops of granites. The drill cores and Rock Quality Designation (RQD) are important tools to decipher subsurface information. Moreover, RQD provides a quantitative assessment of subsurface geology. Therefore, an attempt has been made to decipher the subsurface fracture zones from RQD and drill cores to develop a 3D model to know the continuity of the fracture zones. This will help to keep the foundation in competent rock mass avoiding fracture zones. The Inverse Distance weighted (IDW) anisotropic modelling method has been used to validate the drill core data in respect of fracture zones. Depth of fracture zones determined from drill cores with RQD <20% have been considered in the model to determine thickness of fracture zones and its lateral continuity in 2D as well as 3D perception to decipher the foundation level of the Superstructure. The mechanical breakage and weathered rock mass have been eliminated during modeling the fracture zone. The model indicates that "Very Poor RQD domain (RQD<20%) is interpreted as fracture zones, "Poor" RQD domain (RQD 20-45%) corresponds to less fractured rock mass. The study also revealed that "Fair RQD (45-65) and "Good" RQD domains (>65%) indicate a gradational contact i.e. Fair RQD rock mass isgradually becoming Good RQD rock mass away from the fractures zones. Thus the model has established a relationship between subsurface fracture zones and RQD.The fractures zones may have developed due to the effect of a series of sympathetic fault zones occupy by quartz reefs, doleritic dykes, pegmatite and quartz veins within BGM under soil cover. The model confirms that the RQD within the area of critical structures of the project ranges from Fair to Good category indicating competent rock mass. A few drill holes have been suggested away from the fracture zone to validate the model as well as to increase the confidence level.This model can be utilized for conceptual understanding of the fracture zone in 3D perception to decipher the foundation of heavy civil engineering structures like irrigation andhydroelectric projects (dam, power house etc.), thermal project, heavy industries etc. This will also help to have an idea on in-situ engineering properties /qualities of rock mass as well as adopt suitable excavation methodology to reach the foundation level. The model can give a better visualization of sub-surface geological conditions to fix the foundation levels of different components, to work out the excavations methodologies and helps in timely implementation of the project without time and cost over runs

Copyright

© 2016, the Authors. Published by Atlantis Press.

Open Access

This is an open access article distributed under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/).

Download article (PDF)

TY  - CONF
AU  - Chavhan Rashtrapal H
AU  - Sakhare Vishal V
PY  - 2016/11
DA  - 2016/11
TI  - 3D modeling of the fracture zones to decipher foundation level at Barethi Super Thermal Power Project, Madhya Pradesh, India
BT  - Proceedings of the conference on Recent Advances in Rock Engineering (RARE 2016)
PB  - Atlantis Press
SP  - 223
EP  - 230
SN  - 2352-5401
UR  - https://doi.org/10.2991/rare-16.2016.36
DO  - 10.2991/rare-16.2016.36
ID  - RashtrapalH2016/11
ER  -