1

GE 343 SUBSURFACE EXPLORATIONCH 9 – Hydrogeology

Text Ch. 8.

Dr. Norbert H. Maerz

Missouri University of Science and Technology

(573) 341-6714

norbert@mst.edu

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

5

Pneumatic Piezometer

Hydraulic Transducer

6

Seepage Tests

• Standard Percolation test

• Constant Head Permeameter

• Falling Head Permeameter

Standard Percolation Test

Franklin

7

Franklin

Franklin

8

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)

10

Borehole constant head test

Borehole falling head tests

Franklin

11

Pumping tests

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

14

Step Test

1

5

2

3

4

Pump, recovery, monitoring

1

2

15

Strange test

1

2

3

???

1 5

4

3

2

16

???

3

1

2

Step Test

17

Pressure packer testing (pumping tests)

Permeability Tests

Franklin

18

Injection testing

Slug tests

19

Mechanical slug test

FHWA NHI-01-031

20

Cross hole test

Fractured rock infiltrometer

21

Piezocone Dissipation Tests

FHWA NHI-01-031

Hydraulic conductivity

FHWA NHI-01-031