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1
GE 343 SUBSURFACE EXPLORATIONCH 9 – Hydrogeology
Text Ch. 8.
Dr. Norbert H. Maerz
Missouri University of Science and Technology
(573) 341-6714
Instructional Objectives
1. Explain how to measure groundwater pressures, levels, and hydraulic conductivity in the field.
2
AASHTO Man. Sub. Inv.
What do we want to know?
1. Geology, same is in geotechnical investigations
2. Water levels = pressures
3. Permeability conductivity
4. Contaminants
3
Groundwater Investigations
• Groundwater levels/pressure– Water levels in wells and piezometers– Pressure measurements
• Permeability of the materials– Seepage tests (constant head/falling head)– Pressure packer tests– Pumping tests– Slug tests– Pieziocone dissipation tests
FHWA NHI-01-031
Groundwater levels/pressures
http://www.globalw.com/products/wl500.html
4
Franklin and Dusseault
Hydraulic Twin Tube Piezometer
http://www.lsgi.polyu.edu.hk/sTAFF/zl.li/vol_2_1/05_ding.pdf
6
Seepage Tests
• Standard Percolation test
• Constant Head Permeameter
• Falling Head Permeameter
Standard Percolation Test
Franklin
9
Hydraulic conductivity
• K - hydraulic conductivity [L/T]
• k - intrinsic permeability [L2]
• - mass density [M/L3]
• g - gravity acceleration [L/T2]
• - dynamic viscosity [M/L/T]
gk
K
Hydraulic conductivity (m/sec)
12
Pump Test Graph
Time-Drawdown Curve, Pumping Test
-10
-9
-8
-7
-6
-5
-4
-3
-2
-1
0
1 10 100 1000
Time in minutes
Dra
wd
ow
n R
eco
very
) in
met
res
Drawdown Recovery Monitoring Well
x
13
Transmissivity, Storativity
• T- transmissivity [L2/T]
• K - hydraulic conductivity [L/T]
• b - aquifer thickness [L]
• S = storativity []
• , - compressibility rock. water [(L*T2)/M]
• b - thickness of aquifer [L]
KbT
)( ngbS
Theis solution for porous media
• T - transmissivity [L/T]
• Q - discharge [L3/T]
• s - drawdown [L]
• W(u), u - well function []
• S - storativity []
• r - radius to well where s measured [L]
• t - time of pumping [T]
)(4
uWs
QT
Tt
SrS
4
2