AEG-BWH Meeting: Multiple Investigative Methods to Reduce Uncertainty in Karst

Meeting Announcement:
BWH Section of the Association of Environmental & Engineering Geologists

To reserve a seat, please email Kris McCandless up until Noon on Wednesday, February 19, 2014 at aegbwhsecretary

Date: Thursday, February 20, 2014

TOPIC: Using Multiple Investigative Methods to Reduce Uncertainty in Karst Characterization

PRESENTER: David F. Fenster, PG, Principal Geologist, Eng’g Geology Group Supervisor, Geotechnical & Hydraulic Engineering Group, Bechtel Power Corporation
This subject was presented at the AEG Annual Meeting in Seattle and involved three other authors: W. Godwin (lead author), J. Sowers, and R. Cutsinger.

Characterizing sites underlain by carbonate rock for construction purposes can be tricky at best. When the goal is the construction of critical facilities, it is essential to conduct a site investigation that will result in the reduction of uncertainties to an acceptable level. Carbonate bedrock dissolution can form shallow depressions that initiate at the earth’s surface and propagate in a downward direction, and can form integrated conduit systems at depth. This type of terrain, known as karst, is characterized by dissolution features such as open cavities and fissures, sinkholes, and underground drainage. The hazards to structures built over this type of terrain are well documented. However in cases where karst is not clearly expressed at the surface, for example where the rock is mantled by thick soil, uncertainties in site characterization are increased. Careful geologic characterization using multiple investigative techniques is necessary to facilitate adequate design and mitigate hazard.
In this paper we describe engineering geologic investigations for a nuclear power generating facility sited on carbonate rock in the southern Appalachians, in particular the use of multiple methods to reduce the uncertainty with respect to karst/dissolution hazards at the site. These methods include surface geophysics, vertical and angled borings, surface geologic and geomorphic mapping using LiDAR imagery, statistical analysis of voids, laboratory analysis using XRD/XRF, and development of a site geologic model. Even after the completion of a thorough surface-based investigation, it may be necessary to excavate to foundation depths and to map both floors and walls to further reduce uncertainties.

ADDED SURPRISE: Early indications are that we might be joined at this meeting by several students and their Engineering Geology professor from James Madison University at this meeting. This is encouraging as BWH is hoping to help start a Student Chapter of AEG at JMU.

DATE: Thursday, February 20, 2014
TIME: 6:00 p.m. to 8:45 p.m.
Brewers Alley
124 N. Market Street
Frederick, MD 21701 (Downtown)
Here is the Google Map link to Brewers Alley. (or here:,+Frederick,+MD+21701,+USA&p
w=0&t=h&z=16); Parking is either where you can find it on the street, OR, there is a multistory, municipal parking garage directly behind the restaurant (note the long rectangular building east of Brewers Alley when you open the Google Map/Satellite link). Parking garage entrance is off Church Street, a one-way heading east. If coming north on 355/N. Market Street (from I-270), cross over Patrick Street (the divider between N & S street designations), and turn Right on Church, and left into the garage. If exiting I-70 (from Balto, for ex), go north on North on S. East Street, cross over canal, turn left on E. Patrick, Right on
Frederick and Right on Church into garage on left.

COST (dinner & mtg):
Bring personal or company check or cash to the meeting and pay treasurer before presentation.
Members: $35
Non-members: $40
Students: $25
Members, if you’d like to sponsor one of the students’ dinners, that offer will gladly be accepted.
Details on this in subsequent email announcements.

6:00 to 7:00 pm Social, Networking and Registration
7:00 to 7:45 pm Dinner
7:45 to 8:45 pm Presentation, Questions, Closing Statements

To reserve a seat, please email Kris McCandless up until Noon on Wednesday, February 19, 2014 at aegbwhsecretary

S. J. Stokowski
Vice-Chair, AEG-BWH
508-259-3536508-259-3536 cell


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