2014-11-13_PERMIT FILE - C2010089A ‎(2)‎

• Permit No: C2010089A
• IBM Index Class Name: Permit File
• Doc Date: 11/13/2014
• Doc Name: NHN-001 Ditches As-Built
• Section_Exhibit Name: Appendix 2.05.3‎(4)‎-7
• Media Type: D
• Archive: Yes

Engineering Research Cvnler Geoweb® Cellular Confinement System
1320 Campus Delivery Presto Products Geosystems®
,. Fort Collins, Co 80523 Performance Testing
Maximum Hydraulic Conditions Tested
Design Methodology for Rock Loss
Using data collected from ninety tests,
regression analysis was performed to
develop a methodology for rock loss within
installed Geoweb* as determined by the
Clopper Soil Loss Index. The following
methodology accounts for 96.5% of the
variation in observed rock loss:
S o'" q 0.42 AO-37
L =C
dSO 0.91
where. L = rock loss (ft); GB and GE =
Geoweb factors; S bed slope; q = unit
discharge (ft2 /s); d5o = mean rock size (ft);
and A = nominal area of Geoweb* cell (fe).
An envelope relationship was also
developed, conservatively predicting rock
loss as:
.50.5 q L =Ge g +0.03
d50
Ranges of testing, and confident applicability
to field data are as follows:
S= 2.5 %to 51.84%
q = 0.613 to 31.3 ft2 /s (max. for GW20V and
G W 30V = 6.2 ft2 /s)
d5o = 1.14 to 3.50 in.
A = 44.8 to 187 in2
Specific gravity of rock approx. 2.65
E
aL
I
I
I{l . �►
as
_�5 '_ C•2 ..., 0? 0.?. OA )_- 05 0.5: Je
Measured Rock Loss (11)
�� i1p ?+AkYf � • ....gAVMOq� PCMNS � - P�IYd AON�MMC
Comparison of Geoweb® to Rip -Rap
Geoweb° was evaluated on its performance
as compared to rip -rap with methods
commonly used in engineering practice.
Results showed that required rock size for
aggregate fill with Geoweb® was at least
30% smaller than rip -rap as sized by AN
and Johnson (1991) and at least 50%
smaller than sizes recommended by
USACE (1994). Comparisons emphasize
the ability of the confinement system to
outperform rip -rap and its cost efficiency as
an erosion - protection method, especially in
areas where larger rock is not locally
available.
Appendix 2.05.3(4) -7 Page - 27 - August 2013 (TR -07)
Hydraulic Data
Geoweb&
Rock
Maximum
Maximum
Maximum
Faxknum
Minknum
Maximum
Type
Size
Velocity
Shear Stress
Flow Depth
Rock Loss
Manning n
Manning n
In
tt/s
442
in.
GW20V
1.14
16.12
9.28
0.9'
3.24
0.02
0.04
3.50
11.50
15.10
1.04
1.61
0.03
0.08
GW30V
1.14
12.01
13.17
0.96
4.09
0.03
0.06
2.50
11.69
17.98
1.05
1.86
0.03
0.07
GW40V
'.14
16.31
14.85
11.42
5.98
0.04
0.05
3.50
17.60
15:38
1.79
2,85
0.04
() nF,
Design Methodology for Rock Loss
Using data collected from ninety tests,
regression analysis was performed to
develop a methodology for rock loss within
installed Geoweb* as determined by the
Clopper Soil Loss Index. The following
methodology accounts for 96.5% of the
variation in observed rock loss:
S o'" q 0.42 AO-37
L =C
dSO 0.91
where. L = rock loss (ft); GB and GE =
Geoweb factors; S bed slope; q = unit
discharge (ft2 /s); d5o = mean rock size (ft);
and A = nominal area of Geoweb* cell (fe).
An envelope relationship was also
developed, conservatively predicting rock
loss as:
.50.5 q L =Ge g +0.03
d50
Ranges of testing, and confident applicability
to field data are as follows:
S= 2.5 %to 51.84%
q = 0.613 to 31.3 ft2 /s (max. for GW20V and
G W 30V = 6.2 ft2 /s)
d5o = 1.14 to 3.50 in.
A = 44.8 to 187 in2
Specific gravity of rock approx. 2.65
E
aL
I
I
I{l . �►
as
_�5 '_ C•2 ..., 0? 0.?. OA )_- 05 0.5: Je
Measured Rock Loss (11)
�� i1p ?+AkYf � • ....gAVMOq� PCMNS � - P�IYd AON�MMC
Comparison of Geoweb® to Rip -Rap
Geoweb° was evaluated on its performance
as compared to rip -rap with methods
commonly used in engineering practice.
Results showed that required rock size for
aggregate fill with Geoweb® was at least
30% smaller than rip -rap as sized by AN
and Johnson (1991) and at least 50%
smaller than sizes recommended by
USACE (1994). Comparisons emphasize
the ability of the confinement system to
outperform rip -rap and its cost efficiency as
an erosion - protection method, especially in
areas where larger rock is not locally
available.
Appendix 2.05.3(4) -7 Page - 27 - August 2013 (TR -07)