IMPACT/WP 2 Stability and Failure Mechanisms of Dams

A dam safety research projectKjetil Arne Vaskinn

Test site

Test area at the reservoir lake Røssvatnet

TustervassdammenRøssvatnet

Large scale field-tests 2002

Test Dato Type of dam Objectives of the tests1-02 2002-09-

11 and 12

Homogenous clay Breaching mechanisms in a dam made by cohesive material

2A-02 2002-10-01 og 02

Homogenous gravel dam. Rock fill on downstream slope

Stability with flow through and over the dam

2B 2002-10-08 og 10

Homogenous gravel dam

Stability with flow through the dam

2C 2002-10-15 og 16

Homogenous gravel dam

Breaching mechanisms

3-02 2003. Rockfill dam with moraine core

Breaching mechanisms in a composite dam

4-02 2002-10-24 og 25

Homogenous rockfill 300-400mm

Stability with flow through the dam

Large scale field-tests 2003

Test Dato Type of dam Objectives of the tests1A-03 2003-07-28 –

2003-08-15 Rockfill dam with moraine core

Resistivity and SP investigation for initial dam breach studies and internal erosion detection

1B-03 2003-08-19 - 2003-08-22

Rockfill dam with moraine core

Breaching mechanisms in a rockfill dam with moraine core

2 2003-09-15 – 2003-09-19

Rockfill dam with moraine core

Breaching by internal erosion/piping

3 2003-10-07 – 2003-10-08

Homogenous moraine dam

Breaching by internal erosion/piping

Rockfill dam with moraine core – breaching by overtopping.

Rock filling:.A: 0-500 mm, d10 > 10 mm in downstream fillingB: 300-400 mm in upstream filling

1 meter layer, 4 ton roller compactor. 2 layer with 2 pore pressur sensors in the core, 3 on the foundation of the downstream supporting fill

Test 1B-2003

H=6m1

1,5

B = 2,5m

1

4

H=5,5m

B = 1m

AB

Fjell Water proof sealing

Concrete sill with V-notch weir

Test 1B-2003

Test 1B-2003

Test 1B-2003

Test 1B-2003

Test 1B-2003

Test 1B-2003

Test 1B-2003

Test 1B-2003

Rockfill dam with moraine core – breaching by piping/internal erosion. Identical with 1-2003

Test 2-2003

H=6,5m

1

1,51

4

H=6,5m

200 mm halfpipe with slots on top in sand layer

Concrete sill with V-notch weir

200 mm halfpipe with slots on top. Sand all the way to the top

Test 2-2003

Test 2-2003

Test 2-2003

Test 2-2003

Test 2-2003

Test 2-2003

Test 2-2003

Test 3-2003

Test 3-2003

13:58

Test 3-2003

13:46

Test 3-2003

13:49

Test 3-2003

13:55

Test 3-2003

13:58

Test 3-2003

14:04

Thanks for your attention