The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

DevelopmentDlt off Technology
T h lforfWaterfront
W t ftCreation and Case Study of Continuous
Bl k System
BlockS t
2011.
2011 11.
11 11
Sukhwan JANG,j University
yDaejin
ARRN FORUM 20112Introduction
Case Study of Continuous Block System
A li ti off Continuous
Application
C ti
Bl k S
Block
Systemt
Hydraulic Analysis and Model Test
Conclusion

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

3Current Status of Urban Streams
Forthedecades
beforeFth lastl t ddbf
21st century,
tstream management based on government-led
planning had been mainly considered with theuse of water and flood-control in urban areas.
A results,As
lt theth ecology
loff urbanb
streamst
wasmore deteriorated due to-. Drying of stream-. Straightening of stream channel-. Concrete covering and bank protection-. Artificial riverbed-. Water pollution-. Covering and pavement of stream-. Crossing obstacle in stream-.. Parking lot construction in stream

Damaged aquatic ecosystem in stream
ARRN FORUM 2011

4Research Team Objectives• Development of nature friendly waterfront technology toimprove ecological function as well as hydraulic safetyb tbetweenriverianddbbankkq
ecosystem
yand improvementpof• Restoration of aquatic
diversity in waterfront• Improvement of aesthetic function nearby waterfront andsecuring nature-friendly leisure and resting places for theresidents

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

5Development of Technology for Creation of Waterfront

Mattress ggroyne
y system
ycomposed ofnatural materials in streams

g systemyfor the creation
Soft-bagof natural water front

ARRN FORUM 2011

6

Development of Technology for Replacement of Concrete Covering in WaterfrontGeo-green Loess Fiber Block

Grass-con system of continuous
block system

Soil-layered system reinforced with fibers
for vegetation

Frame system composed of burnedwoods

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

7 Background of Continuous Block System Development☞ Propelled River Restoration and Rehabilitation after 90’s
☞ Hydraulic Safety Problems of Existing Slope
Protection Methods for Close
Close-to-Natureto Nature Application☞ Sustainable Urban Drainage System- Pervious Area Reduction☞ New Method for Safe and Environmental Slope
Protection and Urban Drainage
 Approaches☞ Review of Existing Block Application Systemfor Slope Protection in River Banks☞ Hydraulic Analysis for GRASSCON▶ Physical Model Test ▶ Numerical Analysis
ARRN FORUM 2011

Not Available of Co-existence
bet een H
between
Hydraulicdraulic Safet
Safety andVegetation ?

8-Resistance against High Velocity
Flood in River Bank Block System- Any Problem of Existing Precast
Block System?

Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

9Existing Block System
CAUSES OF PRE-CAST BLOCK FAILURESROTATIONAL SLIP CIRCLE
Caused by Water Intrusion at
the Top of the Slope

ARRN FORUM 201110

CAUSES OF PRE-CAST FAILURES

SURFACE HEAVE
Caused by Static
Pressure between
Two Impervious
Layersy

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

11

사면 활동

SURFACE HEAVE호안기초세굴

ARRN FORUM 2011

12

사면 활동

호안기초세굴

Tractive Forces and Erosion against
High Velocity

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

13

사면 활동호안기초세굴

Interlocking
between Units
ARRN FORUM 201114

THE GRASSCON SYSTEMPERFORMANCEOF REINFORCED
MATERIAL withGRASSIn Situ Applicable
In-SituContinuous
Structure
NO PRE-CASTi

FillerReinforcement
Former
ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

15

GRASSCON – APPLICATIONSEQUENCE

4. CONCRETE & MUD

ARRN FORUM 2011

16ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

17

 PREVENTION OF LOCAL FLOODS RETENTION OF SURFACE WATER INCREASED DRAINAGE LAG TIME
 REDUCED DOWNSTREAM FLOODING
ARRN FORUM 201118RESERVOIRSANDSPILLWAYS

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

19

REPAIRED RIVER
EMBANKMENTS
FROM FLOOD

ARRN FORUM 201120

SUPPORTING
A WIDERANGE OFVEGETATIONIN FLOOD
STORAGERESISTEROSIONUUNDERNEATH
ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

21

TESTED VELOCITYRESISTANCEAGAINST FAILURETO OVER
8METRES/SECONDCONTINUOUS
REINFORCEDSTURCTURE

ARRN FORUM 201122Samples of GrassCon
 하천 호안

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

23

 PhysicalyModel Test
☞ Scale▶ Froude Similarity 1/50
☞ Prototype▶ Length 212m,▶ Width 35m▶ BedB d Sl
Slope 1.6%
1 6%
▶ Bank Slope : L(1:2.0), R(1:3.0)☞ Discharge Condition (Bohyun River) :▶ 200m3/sec (100yr Design Flood)▶ 400m3/sec▶ 600m3/sec (PMF)()

ARRN FORUM 201124

 HYDRAULIC Model Test
☞ Facilities

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

25

 HydraulicyModel Test
☞ Measurement▶ Water Level : Digital Point Gauge▶ Velocity : 1 D Current Meter☞ Supply Discharge Verification▶ Idea-Dejima Eq.
l (h) = 0ln(h)0.72xln(Q)72 l (Q) + 0
0.335
335
0.2

Experiment

0.18

ln(D) = 0.7203670965 * ln(Q) + 0.3350397891

0.16

2

Depth(m)R =0.998814
0.14
0.12
0.1
0.08
0.06

verification
DAGIMA

0.04
0 02
0.02
000.01

0.02

ARRN FORUM 2011

0.03

0.04

0.05

0.06

Q(m 3/s)26

 HydraulicyModel Test
☞ Experiments Performed▶ GrassCon Application
for with/without Vegetation Condition▶ Q = 200, 400, 600m3/sec▶ Measurement for Water Levels, Velocities〉without Vegetation〉with Vegetation
ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

27

 Results of Physical Model Test
☞ Q=200m3/sec Condition▶ Velocities : 6.15 → 4.30m/sec(3.5%~19% decrease)▶ Water Level : 2.86 → 3.85m(1.4%~28% increase)

Reduce Delivery Time of Floodwithout Veg.

With Veg.

ARRN FORUM 201128

 Numerical Analysisy☞ Simulation▶ 1-D Model : HEC-RAS(45 section structure)▶ 2-D
2 D Model : SMS(1141 nodes structure)☞ Model Calibration▶ Parameter (Roughness Coefficient) : 1-D Model- without
ith t Vegetation
Vt ti : 0.017~0.035
0 017 0 035- with Vegetation: 0.040~0.060

1-D Model

2-D Model

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

29

 Numerical Analysis☞ Results of 1-D▶ Difference Comparison with Physical Model- Q=200m3/sec without Veg 4.93~11.74%
with Veg.
2.02~13.00%
3- Q=600m /sec without Veg. 18.87~26.50%
witht Veg.
eg
7.34~16.62%
366 %
676◆
5◆◆◆

■

■

■

▲

▲

▲

5◆

■

유 속(m/sec)유 속(m/sec)

44■
32■

■

▲

▲

◆◆
3■

■

▲

▲

2▲

▲

◆◆
◆
■

▲

1

10004

8

12 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112 116 12004812 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112 116 120◆실험치(600)거 리(m)◆실험치(600)

계산치(600)▲실험치(200)거 리(m)
계산치(200)

without
ith t Veg.
V■실험치(400)계산치(400)계산치(600)▲

withith Veg.
V실험치(200)계산치(200)■실험치(400)계산치(400)

ARRN FORUM 201130

 Numerical Models☞ 2-D Results▶ Difference Comparison with Physical Model-Q
Q=200m3/sec without 1.21~10.22%
with 2.50~10.54%
3- Q=600m /sec without 0.12~5.20%
with 2.34
2 34~1010.86%
86%
7663

■

▲

▲

▲■

◆■

◆■

4▲

◆◆■◆◆

■
유 속(m/sec)유 속(m/sec)

45◆
◆5▲

322■■

▲

▲

◆◆■■

`▲

▲

▲

110004812 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112 116 12004812 16 20 24 28 32 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 100 104 108 112 116 120

거 리(m)◆ 실험치(600)계산치(600)▲ 실험치(200)without Veg거 리(m)
계산치(200)■실험치(400)계산치(400)◆ 실험치(600)계산치(600)▲실험치(200)계산치(200)■실험치(400)계산치(400)

with Veg.

ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

31

 Numerical Analysisy☞ 2-D Simulation ResultsyModel Results than 1-D▶ Closer Results to Physical▶ 2-D Simulation is more Rational

V l it Vectors
Velocity
V t
without
ith t VVeg.

V l it Vectors
Velocity
V t
with
ith VVeg.

ARRN FORUM 201132

 Review Characteristics between Existing Pre-cast Block System andyin Terms of Hydraulicy
Safetyy and Environment
Continuous Block System→ Application Feasibility for Close-to-Nature StreamRiver Works and Sustainable Urban Drainage
 Verification through Hydraulic Model Test for CBS→ Velocities
V l iti DDecrease, WWatert L
Levell IIncrease Numerical Analysis Application→ 1-D, 2-D Simulation : Roughness Coefficient Verification→ 2-D Simulation Analysis is More Rational
Further Study Goes :→Flow Resistance and Maximum Allowable Velocities
ARRN FORUM 2011
Asian River Restoration Network (ARRN)

http://www.a-rr.net/

The 8th International Forum on Waterfront and Watershed Restoration(2011/11/11)

33

Thank you

ARRN FORUM 2011

Asian River Restoration Network (ARRN)

http://www.a-rr.net/