HomeMy WebLinkAboutProposed BERM Structure & Details100—yr,
Post—Developed
Flow: 20.39—cfs±
Existing
Excavated
Drainage
Channel.
Upstream face
of BERM: 3:1
(Hz.: Vt.)
Rock Rip—Rap
Face — See
Details Sheet 2
GRAPHIC SCALE IN FEET
1 INCH = 10 FEET
CONTOUR INTERVAL = 2 FEET
Top of BERM:
10—ft. Wide
Perforated Drain
Riser — See
Details Sheet 2.
Downstream
face of BERM:
4: 1 (Hz.: Vt.)
Rock Rip—Rap
Channel — See
Details Sheet 2.
Concrete Weir —
See Details
Sheet 2
Finished Ground
Contours
Sry Property Line
Proposed new
channel. 2:1
Side slopes,
1—ft. deep.
Irrigation Culvert
7—foot clear from
Ex. Gnd. in ditch to
outside of pipe.
Existing Ground
Con;r>urs
6—in. ADS—N12
Drain Culvert
Story Property Line
Story Property
Line
xisting Culvert
u2r C.R. 150
--inch CMP
faiondition at
inland outlet.
0
0
o,
.mac
Existing Driveway
Culvert: 12—in.
CMP fair condition
at inlet and outlet.
Existing Excavated
Drainage Channel.
Upstream face of
BERM: 3:1
(Hz.: Vt.)
Top of BERM:
10—ft. Wide
100—yr,
Post—Developed
Flow: 20.39—cfs±
Downstream face
of BERM: 4:1
(Hz.: Vt.)
H:\04467\03 drainage mitigation\Design Drawings\TOPO-tcp Ditch -Rev 1.dwg, 11/27/2007 10:24:37 AM, XP 1050C, tcp.pc3
Proposed new
channel. 2: 1 Side
slopes, 1—ft. deep.
Existing Roadside
Ditch — clean and
grade to Garfield
County
requirements.
Perforated Drain
Riser — See
Details Sheet 2.
6—in. ADS—N12
Drain Culvert
l�
:, I I 1
r.
l
Story Property Line
GRAPHIC SCALE IN FEET
1 INCH = 40 FEET
CONTOUR INTERVAL = 2 FEET
.-
0
Q m
.E
0
I m
U
w
Added new outfall channel to direct flows West. Per GARCO request.
REV I DATE
NO. REVISION
•
04/22/06
1-f:\0446703 drainage mitigation\Design Drawings\BERM Details-Rev2.dwg, 11/27/2007 10:22:44 AM, XP 1050C, tcp.pc3
Rock Rip—Rap
per Specs.
,,.. -1.
il
Wt
Compacted
Native Soils
/\\/
/\\ \/��/'
// //\/\ \/
Wb
Existing Ground Surface
Mirafi 500X
Fabric.
NOTES:
1) Top Width of Channel, Wt = 8.0' (matches April 2004 Channel Width)
2) Bottom Width of Channel, Wb = 1.5' (matches April 2004 Channel Bottom)
3) Channel Depth, d = 1.3' (matches April 2004 Channel Depth)
4) Channel Capacity: 30.5 cfs±
Flowline of Channel —
extend to the north and
west to tie to existing
drainage culvert under
County Road 150, see
plan view.
BERM BOTTOM CHANNEL DETAILS
Existing Top LEFT (West) Bank
of Channel — Grade to be at
least 1—foot LOWER than
RIGHT (East) below BERM.
Existing Top RIGHT (East) Bank
of Channel — Grade to be at
least 1—foot HIGHER than
LEFT (West) below BERM.
Rock Rip—Rap
per Specs.
Mirafi 500X
Fabric.
— 2.00' (min.)
2
8.00'
Channel Capacity: 138 cfs±
Compacted
Native Soils
BERM FACE CHANNEL DETAILS
Not to Scale
Create 2—foot deep, triangular channel, with 2:1 Side
Slopes, rock rip—rap lined below the concrete weir, to
carry flows over downstream face of BERM. See BERM
Face Channel Details.
BERM Top 10.00' (min.)
Elev. 7119.00' (min.) — East Side
Elev. 7118.00' (MAX.) — West Side
Surround Perforated ADS—N12
culvert with 1—foot thick depth of
4—inch Washed Gravel.
Flowline of Concrete Weir to be level,
and 1.30' below top elevation of BERM.
Top LEFT (West) Bank of
Channel — Grade to be AT
LEAST 1—foot LOWER than
RIGHT (East) above BERM.
Low—Flow Berm Drain: Extend 6—inch Perforated
ADS—N12 culvert vertically to at least 1—foot beyond
the top of the channel, in the location shown on the
Site Plan (Sheet 1) and the Cross—Section View (this
Sheet).
1.00'
(min.)
Cut—Off Wall —
construct in
accordance with
details and
specifications.
------------
Approximate new
grade line.
Extend 6—inch ADS—N12 culvert
approximately 10—feet beyond
toe of BERM. Provide rip—rap
outfall for the flow.
Yl
7
Approximate NEW top LEFT
(West) Bank of Channel.
Overall length of BERM: 100'±
Grade outfall of BERM spill—way according to the details. Remove minor berms and swales,
and provide positive slope away from toe of BERM. See BERM Bottom Channel Details.
II
.111
`...�
r -
... t,.)
d
t t
l
I,•l . 4!L Icy..,
L..1)'
Grade Top of West
Channel Bank to
Elev. 7118.00
(MAX.) to help
direct overflow to
the West of Berm.
WEST SIDE
Maintain constant, )ositive slope of 6—inch culvert, do
not create any low spots or bellies.
PROFILE OF BERM
Not to Scale
6—inch ADS—N12 End Cap —
keep accessible for cleaning.
Centerline Length a- Top of BERM 20.6'±
EAST SIDE
Top of BERM
ELEV: 7117.09'±
Grade Top of East Channel Bank
to Elev. 7119.00' (min.) at least
4' wide in area of Berm, to help
prevent overflow from going East of Berm.
Theoretical ORIGINAL Ground
Surface
Over excavation Line shall be
1—foot beyond Original native
ground soils.
Existing Side of Ditch, Slope
Varies
Overexcavate Depth: 1.00' (min.)
Bottom of Ditch
ELEV: 7108.14±
Bottom
Width
Varies
4.8'±
Finished Ground
3.00'
(min.)
Rip—rap entire upper face of
BERM, use rocks with D50 of at
least 2—feet, set into earth face,
and compact in place with
smooth—drum roller.
ment Flow: 20.39 cfs±
100—yr Post—Develop
Top RIGHT (East) Bank of
Channel — Grade to be AT
LEAST 1—foot higher than LEFT
(West) above BERM.
Flowline of Channel
Surround End of Drain Line with
1—foot thick depth of 4—inch
Washed Gravel.
BERM Top 10.00' (min.) -
--
— 1.30'
Existing Ground
Native soils placed as fill on East Side
of Dam should be compacted to at
least 95% of maximum theoretical
density as determined by the
Standard Proctor.
Perforated 6—inch ADS—N12 Riser — Drill 2 -inch Diameter
holes in VALLEYS of pipe, 4 holes per VALLEY, 1—foot O.C.
SURROUNDED BY 1—foot thick depth of 4—inch WASHED
GRAVEL FILTER.
Over—excavate a 4—foot wide Trench, in the center of
the BERM, at least 1—foot Deep. See Profile Details.
Install 6—inch ADS—N12 Culvert at
Lowest Point in Existing Ditch — at
either corner of bottom of ditch.
CROSS—SECTION VIEW )F BERM AND WEIR — Looking NORTH
Not to Scale
CONSTRUCTION SPECIFICATIONS:
1) Excavation of Existing Ground for Cut—Off Wall in BERM: Trench for cut—off wall shall be advanced to a depth of at least 1—foot into native, undisturbed soils. Trench for cut—off wall shabe at least 4—foot wide in the direction of the flow of the existingditch.
ch.
2) Material selection for cut—off wall: Material to be used in the construction of the cut—off wall may be chosen from existing, native soils, only if they meet the following characteristics: a,Native soils shall be inspected by a Colorado Registered Professional
Geotechnical Engineer, and his recommendations as to their suitability for the intended purpose shall govern their selection or rejection. b) If, in the opinion of the Geotechnical Engineer, no fficient quantities of suitable native soils are found on the site, then the
Geotechnical Engineer shall make a recommendation as to the type of soils to be imported and used for the cut—off wall. c) Approximate volume of the cut—off wall is 25 cubic yards (compted volume). Assume 15% additional for compaction, for approximate) 29
cubic yards of material.
Y
3) Compaction Specifications for the cut—off wall: All materials, regardless of the source, shall be moisture—treated to within +/— 2% of the optimum moisture content. All materials, regard's of the
greater than what is recommended by the Geotechnical Engineer for the equipment being used for compaction, and the type of material being placed. Density: All soils used for the cut—off w( shall be
Theoretical Density as determined by the Standard Proctor.
4) BERM Upstream Soils and Face: Moisture—treat to within 2% of Optimum Moisture Content, and compact to 90% of Maximum Theoretical Density according to the Standard Proctor test. PI=
use compaction equipment to set well into BERM face.
5) BERM Downstream Soils and Face: Moisture—treat to within 2% of Optimum Moisture Content, and compact to 90% of Maximum Theoretical Density according to the Standard Proctor test. Eavate the BERM face
place rock rip—rap armoring on channel sides and bottom.
6) BERM Bottom Channel: Place rock rip—rap armoring with native rocks having a "d50" of 2—feet, and use compaction equipment to set well into channel.
7) Culvert Placement: The material used for the culvert shall be ADS—N12 10.8 psi Pressure—Rated Culvert, with pressure rated fittings. The slope for the culvert shall be prepared as shown of drawings, and the culvert shall be placed at approximatelythe grade
shown. Care shall be taken in placement of the soils for the bedding and under the spring—line of the culvert so as to avoid any voids or areas of inadequate compaction. In the area of the c -off wall, the soils shall be compacted to the specifications for the
cut—off wall as described above.
re ate Base Course, and shall be moisture—treated and compacted to 95% of the Maximum Tr,
gg g P retical Density as determined by the Modified Proctor. The welded wire
8) Concrete Weir construction: The soil below the Concrete Weir shall be constructed of Class -6 A
mesh
l
off the
he
contenth5l% besupported
8%.poCutd--off wallspareared requiredce with onboth the supports
sary to ensure a downstream facesch clearance
Conc Concrete the
asprshownepared
ongrade.
he revThe
ised plans.concrete
The used
concrete shallConcrete
be surfac shallir with meet the broom Ilfinisr pecifications: minimum 28—day strength shall be 3,000 psi, air
upstreamWeir,
9) Rock Dimensioning: The notation referenced above "dam" (spoken as: dee—sub-50"), refers to a rock sizing classification that requires that at least 50% of the rocks used shall have a minimurrCmension of a certain size, (in this case, of 2—feet). Therefore,
rocks should be chosen such that at least 50% of the rocks in the BERM upstream end, or the various channels have a minimum dimension of at least 2—feet. The remaining spaces between thesElirger rocks shall be filled with smaller rocks, so that there are not
large spaces between rocks.
source, shall be placed
placed and compacted
in lifts, the depth of which shall be not
in lifts, to achieve 95% of the Maximum
rock rip—rap armoring with native rocks having a "d5" of 2—feet, and
channel deeper than
shown in drawings, in
order to
Concrete Weir
Cut—Off
BERM Face Channel
3.00'
(min.)
f
•
Welded Wire Mesh
Reinforcing, centered in
concrete.
Concrete Depth
0.50' (min.)
3
Concrete Weir
Cut—Off
6—inch (min.) thick bed of
Compacted Class -6
Aggregate Base Course.
CROSS—SECTION OF CONCRETE WEIR
Not to Scale
d
6—inch (min.) thick bed of
Compacted Class -6
Aggregate Base Course, per
cut—off wall specs.
Wb
Concrete: 0.50'
(6") (min.)
Welded Wire Mesh Reinforcing,
centered in concrete.
NOTES:
1) Top Width of Concrete Weir, Wt = 8.0' (matches April 2004 Channel Width)
2) Bottom Width of Concrete Weir, Wb = 1.5' (matches April 2004 Channel Bottom)
3) Channel Depth, d = 1.3 (matches April 2004 Channel Depth)
4) Channel Length, (not shown) approximately 8—feet to 9—feet.
5) Volume of Concrete, approximately 3 cu.yds.
6) Concrete Cut—Off Walls required on both upsteam and downstream faces,
see Cross—Section for details.
6) Channeled Capacity as Weir: 6.7 cfs±.
END—SECTION OF CONCRETE WEIR
Not to Scale
Coh,
O
O
Lu
Lu
Ln
iI cz�
o V�
4;))
L. _ro
m �O
ON
q(1) LI)O
U g'
zo
W
rAw�
VJ �
Wm
1- 0
1.0
Uca
O�
(I) Z
da
z
W
W
ct
0:1
ictO
ou
N
Em
0;
U00
zI,
Z
Wa.
4
Wa
o
O
Zr
WW
a�
m m
Em
�0
m
C
ON
In W
in ;
N
tea
0/I -
OZ
nZ
DRAWN BY: tcp
1V
a
w
0
3
0
s
H
J
U
0
NetN.
CO
Lu
--(cj
o_
C•11
0
N
I—
w
w
I
BERM Details-Rev2.dwg
0
DIRECTORY: H:\04467\03 drainage mitigation\Design Drawings\
O.
1
a.
Ct.
0
ate. m
0 }
I co
U
V
an
0.
w
d
0
a
a,
a
V
0
a.
0
0
w
a
M
0
ea
eol
er
Lu
I-
0
M
N
O
W
Z