20071203120808.pdfo� Ebb City of Edmonds
Rix.. PLAN REVIEW COMMENTS
BUILDING DIVISION
FSS t.$go (425) 771-0220
DATE: December 3, 2007
TO: Ross Woods
E-mail: ross@triaddev.com
FROM: Ann Bullis, Assistant Building Official
r'
RE: Revision to Permit 2006-0695
Project: MSE walls and rockeries
Project Address: 21, 31 & 41 Pine Street
The City's consultant has reviewed the revised plans/documents for the above noted project. His
comments are attached. Provide written responses to each comment and where changes can be
found on the plans/calcs. Please resubmit to Marie Harrison, Permit Coordinator..
MEMORANDUM
DATE: 2 December 2007
TO: Ann Bullis, Chief Pian Reviewer, City of Edmonds, WA
FROM: Jerry J. Barbera, P. E., MSCE, and Construction Codes Consultant
RE: Review Plans for Combining Rockeries with MSE Walls
ID #: My P.C. # 1123-407 and yours is 2006-0695
I reviewed the plans and Soils Report # T-4893 by Terra Associates, Inc., dated 29 October 2007, for a
proposed combination of Mechanically Stabilized Earth wall design, which also included rockeries. I also
received a copy of an e-mail from the soils engineer stating what the concept was for the design was.
The site in which the rockeries -MSE walls will be placed occurs at many locations in the Port Edwards
project in the SE corner where Building # 7 and Loop Road intersect.
I have the following comments on the design and report (section references are from the 2006 IBC):
1. The plans specify SYNTEEN SF 55 or equal geo-synthetic material. Did they actually use that
material? In my research, here is what I found:
a. WSDOT has only preapproved Tensar ARES or Tensar Mesa material for such uses.
b. If SYNTEEN is used, http:l/www.geo-synthetics.com/Soil Reinforcement Geogrids.html
shows it under the trade mark name of Tenax MS Biaxial Geogrids, but the site doesn't
mention QC or other IBC issues and requirements. It doesn't give design procedures.
c. The only ICC ER Report that I found actually was associated with Vendura or Candura
segmented retaining wall systems, ER # 5515, where it was listed as an alternative to
the ones they listed therein. Even though that report was for the '97 UBC, it could be
used for that material if the specifications given in Report Section 2.2.3 didn't change in
the past 10 years+. I include the report for your information as well as for the soils
engineer.
d. If SYNTEEN is not used, what are the other material's technical data, listing, and
criteria? Sections 1703.1 and 1703.4. Without any ICC Evaluation Report to ensure the
alternate complies with IBC criteria for alternative material including their structural
resistance qualities and independent QC by an agency you can approve, you would
have no basis to ensure they were actually equivalent. Sections 1703.4.2 and 1703.5.
2. What is the general design procedure? The spread sheets the soils engineer included doesn't
provide any verifiable equation or any information for specific products to be used. Sections 2.3
and 2.4 of ER # 5515 do give the general engineering design criteria, but the material submitted
by Terra Associates doesn't offer at least a hand calculation method to verify their work.
3. Seismic was mentioned in the design on the "calculations", but I can't see from that information
that it actually complies with Section 1802.2.7, Item # 1 without further data and design details.
How is this loading related to the Mononobe-Okabe Equation and the PGA?
MEMO. P.C. # 1923 407 and Edmonds # 2006-0695
Review Plans for Combining Rockeries with MSE Walls
2 December 2007
Page 2 of 2
4. Triad Figures 1 & 218 potentially have many design and inspection issues:
a. . The geo-synthetic material surrounds retained earth in layers of dirt 2'± thick as shown as Figure # 2.
However, those in Figure # 1 only have one layer of the material above the layers below that must be
compacted but has to leave a space for gavel to be between the eventual rockery and the geo-grid
layers. Supposedly, the fabric is staked so that they are in tension, but it is not clear how this can be
done physically before compaction and how the gravel will hold the material in tension between the
rock lifts. It needs to be defined and to be acknowledged by the inspector who checked them.
b. What is the basis of the formula that gives length of the geo-grid material based on height of the wall?
c. How do we verify that the surcharge from the up4o-4'-high rockery, rock filter material, and structural fill
is included in the design of the geo-synthetic material behind the lower wall in Figure # 1?
d. Why isn't the geo-grid under the up -to -4' -high rockery 6' long in Figure # 1? The table in Figure 2 states
> 4' should be that long.
e. How do surcharges' from walkways, the pool, and the weight of water in the pool shown on Cross
Section EE14F affect the upper rockery as well as the MSE "wall" below them from that surcharge?
f. What is the action of the up -to -&-high rockery weight itself affecting the slope relative to Section View
K-K/4F?
g. How do slopes below both wall types 1 and 2 shown in Cross Sections & E-E14F resist the surcharges
on them? Sections 1805.3.2 and 1805.3.5, and Figure 1805.3.1
h. There will be a fire lane above one or the other of these wall types.
L What type of fire engine(s) does the City have that might have to go out to this site?
ii. What are the wheel loads for them and how are they converted to pressure behind the wall(s)?
iii. What are rolling wheel loads and how are they converted to pressure or force behind the wall?
L What friction angle and cohesion value was used for the foundation soil to be able to check sliding 6"
below the geo-synthetic material where the last geo-g rid is provided? Section 1804.3 and 1806.1
5. What erosion control planting or other method protects the slopes? Section J110.1, IBC page 608
1 will submit an invoice based on the permit fee for the rockery or the number of hours I took to do the review,
whichever is larger, when the review has been completed.
Enclosures: General material already sent in an e-mail on 30 November 2007 & copy of ICBO ER # 5515
LEGACY REPORT ER -5515
\ s Reissued April 1, 2007
ICC Evaluation Service, Inc. BusinesslRegional Office ■ 5360 Workman Mill Road, Wh'rmer, Calfomia 90601. (562) 699-0593
Regional Office ■ 9W Montclair Road, Suite A, Birmingham, Alabama 35213 ■ (205) 599-9800
www.icc-es.org Regional Office ■4051West FkissmoorRoad, Country Club Hills, MinDis60478■(708)799-2305
Legacy report on the 1997 Uniform Building Code"11
DIVISION: 02 --SITE CONSTRUCTION
Section: 02830—Retaining Walls
VERDURA AND CANDURA SEGMENTAL RETAINING
WALL SYSTEMS
SOIL RETENTION PRODUCTS, INC.
2501 STATE STREET
CARLSBAD, CALIFORNIA 92008
1.0 SUBJECT
Verdura and Candura Segmental Retaining Wall Systems.
2.0 DESCRIPTION
2.1 General:
The Verdura and Candura wall systems utilize segmental
concrete blocks for construction of gravity and soil -reinforced
retaining walls_ Construction of soil -reinforced retaining walls
is achieved by combining the block units, geosynthetic
reinforcement, and compacted soil. The wall system is
assembled in running bond without mortar or grout and, if
specified, with horizontal layers of geosynthetic reinforcement
in the backfilled soil mass.
2.2 Materials:
2.2.1 Block Units: The Verdura and Candura concrete
blocks are trough -shaped and vary in dimension and weight.
A summary of block types, dimensions, and weights is
presented in Table 1_ Schematics of the various block
geometries are shown in Figures 1 through 7. Block units and
their dimensional tolerances must comply with UBC (1997
Uniform Building Code") Standard 214, with a minimum 28 -
day compressive strength of 4,000 psi (27.6 MPa) on the net
area, and a maximum water absorption of 6 percent- Prior to
construction, evidence of compliance with this report and
UBC Standard 21-4 must be furnished to the building official
for approval.
2.2.2 Geosynthetic Reinforcement: Geosynthetic
reinforcements described below are to be stored at
temperatures not lower than –10T (-23°C); must not be
subjected to prolonged exposure to sunlight, to prevent UV
degradation; and must not be put in contact with mud, wet
cement, epoxy or other adhesive materials_
2.2.2.1 Geogrids: Geogrids manufactured by Mirafi and
Synteen Technical Fabrics are compatible with the Verdura
and Candura soil -reinforced retaining wall systems. All
geogrids consist of polyester yarns with polymeric coating,
formed into a grid shape_ Applicable design properties are
shown in Table 2. Shear stress interaction and connection
capacities are addressed in Tables 3 and 4, respectively_
2.2.2.2 Geosynthetic Fabric: Posi-Dura fabric (Mirafi
HS667), manufactured by Mirafi, is a woven polyester
geosynthetic fabric used specifically in the Posi-Dura
connection system described in Section 2.2.3 of this report.
Posi-Dura fabric (Mirafr HS667) geosynthetic fabric is
supplied with prefabricated sewn sleeves at regular intervals.
Attachment of the Posi-Dura fabric and pipe system to the
Vedura and Candura blocks is conducted as described in
Section 2.2.3. Applicable design properties are shown in
Table 2. Shear stress interaction and connection capacities
are shown in Tables 3 and 4, respectively.
2.2.3 Posi-Dura Reinforcement Connection System: The
Posi-Dura is a proprietary positive connection system that
may be used alone or in conjunction with the primary soil
reinforcement geogrids described in Section 2.2.2.1 and any
Verdura or Candura segmental concrete blocks_ The system
may be used as the primary soil reinforcement for Verdura
wall systems having a height of less than 8.0 feet (2438 mm),
or Candura 25 and Candura 35 retaining wall systems having
a height of less than 6.0 feet (1829 mm). The Posi-Dura
system consists of a Posi-Dura Pipe [1 -inch (25 mm) nominal
diameter Schedule 80 pipe complying with ASTM D 1785-99,
cut to fit inside block rails.), Posi-Dura Fabric (Mirafi HS667
geosynthetic fabric described in Section 2.2.2.2) and Verdura
Block. The pipe is either inserted into the prefabricated sleeve
of a minimum 7 -inch -wide (178 mm) strip of geosynthetic
fabric, or the fabric strip is looped around the pipe; both
components are then inserted into the inner gusset walls of
the concrete blocks, and are embedded with the appropriate
infill material. The PVC pipe must be long enough to fit
snuggly between the inner width of each block, with a
maximum gap of inch (12.7 mm) between the wall and the
end of the pipe. If the fabric is looped around the pipe, the
overlapped length extending into the backfill soil is 18 inches
(457 mm) or the length required (by calculation) to develop
full tensile load capacity of the fabric, whichever is greater.
See Figure 8 for details of the Posi-Dura connection system.
2.3 Design:
The system is designed as a gravity or soil -reinforced
retaining wall system, and depends upon its weight and
geometry to resist lateral earth pressures and other lateral
forces. Lateral earth pressures most be determined using the
Coulomb theory. The design must include evaluation of both
external and internal stability, along with consideration of
external loads generated by surcharges and seismic activity.
White external stability analyses are to be similar to those
required for conventional gravity retaining walls, internal
stability analyses of reinforced walls must consider the block -
to -block shear for the Candura block and the lip strength for
ICC -ES legacy repons are nor to Ire CanS1174ed us represerrliug aesdtetics or arm other airrihutes not specijrcaliv addresser, nor are then to be consa7wd as
an endorsenreni glAe subject ol'the report or a recommendation joy its zine. There is no rrarr ante b.V ICCEvaluatiun Service, Lye., espress or implied, as to 1
unv inding ar other inner in this report, or as to arrr product covered bT the report. y�.x �n a 10e
Copyright O 2007 Page t of 1111
Page 2 of 11
the Verdura block, the allowable reinforcement tension pullout
resistance behind the active failure zone, and the
reinforcement connection strength at the facings. Also, the
assessment of the global stability must be evaluated by a
registered design professional and approved by the building
official_ The minimum factors of safety are in Table 5-1 of the
National Concrete Masonry Association (NCMA) Design
Manual for Segmental Retaining Walls (2nd edition, 1997.)
For seismic loads, the safety factors may be reduced to 314 of
the tabulated static analysis safety factors_
A foundation investigation in accordance with Section 1804
of the UBC is required for each site_ The investigation
determines the soil properties and the values for design. The
design method must be based on accepted engineering
principles and judgment. Design details are noted in the
National Concrete Masonry Association (NCMA) Design
Manual for Segmental Retaining Walls (2nd edition, 1997); the
FHWA publication entitled "Mechanically Stabilized Earth
Walls and Reinforced Soil Slopes Design and Construction
Guidelines" (2001); and Section 5.8 of the Standard for
Highway Bridges, 17d' edition (AASHTO, 2003)-
2.4 Structural Analysis:
Structural calculations must be submitted to the building
official for each wall system design. The structural analysis
must be based on accepted engineering principles; the
NCMA Design Manual; and either FHWA Publication No.
FHWA-NHI-00-043 or Section 5.8 of the 2003 Standard for
Highway Bridges, 17"' edition (AASHTO, 2003). A summary
of the overall design process is presented in Figure 10_ All
contact surfaces of the units must be maintained in
compression. The compression stress is limited to a
maximum of 100 psi (690 kPa). A net resultant tension force
is prohibited in any portion of the retaining wall- The shear
resistance between Candura block units is determined using
the following equation:
V„ = 115 + Ww tan 39'
where:
V, = Shear resistance, pounds/linear foot (kNlm).
W„, = Weight of wall above interface, poundsllinear foot
(kNlm).
The shear resistance between Verdura block units is
provided by the following equations:
Verdura 30 and 40:
V„ = 3582 + W tan 32-8° s 5991 plf
For SI: V„ = 52.26 + Ww tan 32.8' <_ 7.91 kNlm
Verdura 50 and 60:
V„ = 4119 + W. tan 34.3° < 4971 plf
For SI: V„ = 60 + W. tan 34.3` < 72.53 kNlm
2.5 Installation:
For walls more than 3.3 feet (1.0 m) in height, the wall
systems require geosynthetic reinforcement for wall
stabilization. The Verdura Segmental Retaining Wall Systems
are inclined 70 to 76 degrees from the horizontal_ The
Candura Segmental Retaining Wall Systems are vertically
inclined. The in-place wall must be constructed so as to be
within the tolerances specified by the manufacturer or the
NCMA design manual, whichever is more restrictive.
At elevations where PVC pipe and wrapped geogrid are
used to provide a mechanical connection to the fascia,
Verdura blocks having notches in the rails must be employed.
The connection between the continuous PVC pipe, geogrid,
and notched Verdura block is made by wrapping the geogrid
ER -5515
around a continuous section of Schedule 80 PVC pipe set
into the notches of the block rails. Continuous sections of
Schedule 80 PVC pipe are set into the notches of the Verdura
rails, thus pushing the geogrid downward into the notches.
The short section of the geogrid extending beyond the PVC
pipe is pulled back over the pipe and set back into the soil fill
behind the block units. Subsequent lifts of Verdura blocks and
soil fill layers secure the system into place.
Backfill used in the soil -reinforced mass must consist of
approved materials placed in compacted lifts.
Recommendations for the wall drainage system, including
drain pipe use and depth of backfill blanket, are to be
provided by the soils engineer of record for the project.
Ordinarily, a blanket of cohesionless backfill is placed behind
the wall. In cases in which the segmental retaining wall units
ate placed in an open condition and the reinforced soil is
cohesionless and free -draining, the use of a blanket of
cohesionless backfill may be omitted upon the
recommendation of the soils engineer. If the soils are found
to have poor drainage qualities, a perforated drain -line
system must be designed and installed to prevent hydrostatic
pressure build-up behind the wall in accordance with
accepted engineering practice.
After backfilling the bottom course, blocks in subsequent
courses are laid with the desired inclination and
simultaneously backfilled. Maximum spacing between blocks
is 9 inches (229 mm). With the maximum spacing of the
blocks, the wall system may be placed with tighter concave or
convex horizontal curves, with a minimum radius equal to
one-half the wall height_ To conform to the inclination curves,
and depending on the intended curvature of the wail, the
spacings are to be adjusted at the front or the back, but are
not to exceed 9 inches (229 mm) between the blocks.
For soil -reinforced retaining wall systems, geogrids are
placed at elevations specified by design. The backfill surface
must be placed and compacted to within approximately 314
inch (19.1 mm) of the top block -elevation to which placement
of the geosynthetic reinforcement is required. The geogrid is
fully embedded between courses of the blocks, and the
blocks are filled with appropriate infill material in accordance
with the block manufacturer's recommendations. After
unrolling, the geogrid is hand -pulled until it is taut, flat, and
free of wrinkles, and is anchored to the compacted backfill
prior to backfilling over the grid. Adjacent geogrid rolls are
butted side-by-side without overlap, and splices must be
avoided_ The roll (machine) direction is the direction of the
principal reinforcement. Figure 9 illustrates geogrid
connections to block. Where the Posi-Dura Connection
System is used, installation must be in accordance with
Section 2.2.3.
2.6 Special Inspection:
Special inspection during installation must be performed in
accordance with Section 1701 of the UBC. The special
inspector must be qualified by the building official in
accordance with Section 17012 of the UBC. The inspector's
responsibilities include verifying:
1. Unit dimensions.
2. Unit compliance with UBC Standard 21-4, including
compressive strength and water absorption as described
in Section 2.2.1 of this report.
3. Foundation preparation.
4. Unit placement, including alignment and inclination.
5. Geosynthetic reinforcement, and placement with respect
to elevation and orientation_
6. Installation of Posi-Dura System components, when used_
Page 3 of 11
7. Backfill placement and compaction.
2.7 Identification:
The manufacturer's name (Soil Retention Products, Inc.), the
product name and the evaluation report number (ICC -ES ER -
5515) are noted on a label affixed to the shipping pallet of the
concrete blocks. Each roll of geogrid and geosynthetic fabric
reinforcement is labeled with the geogrid or geosynthetic
fabric manufacturer's name and address, and the product
designation.
3.0 EVIDENCE SUBMITTED
Design manuals, test data and calculations, descriptive
literature, and a quality control manual.
4.0 FINDINGS
That the Verdura and Candura retaining wall systems
described in this report comply with the 1997 Uniform
Building Code TM (UBC), subject to the following
conditions:
4.1 The system is designed and installed in accordance
with this report, the manufacturer's instructions,
and accepted engineering principles.
4.2 All units comply with this report and UBC Standard
21-4, and evidence of compliance is submitted to
the building official.
4.3 Special inspection is provided in accordance with
Section 2.6 of this report.
ER -5515
4.4 The wall design procedures and manuals are
submitted to the building official for approval.
4.5 A foundation investigation in accordance with
Section 1804 of the UBC is provided for each project
site.
4.6 Details in this report are limited to applications in
areas outside of groundwater. For applications in
which free-flowing groundwater is encountered, or
where wall systems are submerged, the installation
and design of such systems must comply with the
appropriate sections of the NCMA Design Manual
(1997) andthe recommendations of the project soils
engineer. Footings in groundwater are contingent
on appropriate soil and engineering analysis reports
being submitted to the building official forapproval.
4.7 Calculations demonstrating that the structural
design complies with this evaluation report are
submitted to the building official for approval.
4.8 The Verdura and Candura concrete blocks are
manufactured by Soil Retention Product, Inc., at
their manufacturing facilities located in Romoland,
California.
This report is subject to re-examination in two years.
TABLE I -SUMMARY OF PHYSICAL PROPERTIES OF VERDURA AND CANDURA SEGMENTAL RETAINING WALL UNITS
BLOCK TYPE
WIDTH
(inches)
HEIGHT, TO TOP OF RAIL
(Inches)
HEIGHT, TO TOP OF LIP
(inches)
DEPTH
(inches)
APPROX. WEIGHT
(pounds)
Verdura 30
18.0
6.25
9.5
12
58
Verdura 40
18.0
7.75
10.75
12
82
Verdura 50
18.0
6.25
9.0
18.0
110
Verdura 60
18.o
7.5
10.75
18-0
132
Verdura 60w
18.0
7.75
10.75
18.0
132
Candura 25
17.9
6
MA
12
55
Candura 35
17.9
8
MA
12
77
For 51: 1 inch = 25.4 mm, 1 pound = 0.45 -kg.
NIA = Not applicable.
TABLE 2-GEOSYNTHETIC REINFORCEMENT PROPERTIES
MANUFACTURER
TYPE
GRADE
MASSIAREA
(0z.Iyd2)
LONG-TERM ALLOWABLE
TENSION LOAD, MD
(poundsift)
Mirafi
Geogrid
5XT
6
1,733
Mirafi
Geogrid
8XT
10
3,089
Mirafi
Geogrid
10XT
12.5
4,116
Mirafi
Geogrid
18XT
15
4,641
Mirafi
Geogrid
20XT
20
5,968
Mirafi
Geogrid
22XT
27
8,534
Mirafi
Geolextile
HS667/Posi-Dura
Fabric
12
3,795
Mirafi
Geogrid
HS6671Posi-Dura
Fabric
12
884,
Synteen
Geogrid
SF55
10
1,991
Synteen
Geogrid
SF80
11.7
2,936
Synteen
Geogrid
SF110
17.8
5,154
For SI: 1 mil = 0254 mm, 1 pound = 4,45 N, 1 o7.lyd.` = 33.9 g1m`, 1 pound/fool = 14.6 Nlm, 1 inch = 25.4 mm.
'Equivalent full coverage strength for Posi-Dura used with 9 -inch spacing between Verdura Units.
2For allowable design loads, divide tabulated values by 1.5.
Page 4 of 11
TABLE 3—COEFFICIENT OF SHEAR STRESS INTERACTION
ER -5515
MANUFACTURER
GRADE
SOIL TYPE COEFFICIENT"'
Mirafi
All geogrid grades
ML, CL 0.7
SM, SP, SW 0.8
GP, GW 0.9
Synteen
All geogrid grades
ML, CL 0.7
SM, SP, SW 0.8
GP, GW 0.9
Mirafi
HS667'
SM 0.9
Soil Retention Products2,'
HS6671Posi-dura over 10XT
SM 0.78
For SI: 1 inch = 25.4 mm.
'The coefficient of interaction was determined by testing the interface coefficient of friction of HS667 on top of 10XT. Silty sand (SM) was placed
above and below the two geosynthetic grades.
'The Posi-Dura is a proprietary connection system described in Section 2.2.3 of this report.
'The coefficient is based on a 9 -inch spacing between the blocks.
'Refer to Table 18-1-A of the 1997 UBC for definitions of soil types.
'For design, divide tabulated values by 2 tan 0, where 6; is the peak angle of internal friction for the reinforced soil (deg).
TABLE 4—FACING CONNECTION CAPACITY'2
BLOCK TYPE
CONNECTION
FRICTIONAL!
MECHANICAL
(WITH NOTCH)
ULTIMATE CONNECTION STRENGTH,
P, (poundslfoot)
SERVICE STATE
CONNECTION
STRENGTH, P ,
(pounds/foot)
Verdura 30, 40
Candura 25, 35
Mirafi 5XT Geogrid
Frictional
NIA
P, = 490 + N tan 9' a 750
Candura & Verdura (ail)
Posi-Dura'
Mechanical
NIA
Ps = 1000
Verdura 30, 40
Mirafi 5XT Geogrid
Mechanical
P, = 3527
Ps = 2180
Verdura 30, 40
Mirafi 8XT Geogrid
Mechanical
P, = 3832 + N tan 21.7° < 4447
Ps = 2232 + N (tan 8.9)°
Verdura 30, 40
Mirafi 10XT Geogrid
Mechanical
P, = 2091 + N tan 64.9° < 6000
Ps = 2875
Verdura 30, 40
Mirafi 20XT Geogrid
Mechanical
P, = 4211 + N tan 62.2° s 7840
PS = 2971 + N (tan 29)°
Verdura 30, 40
Synteen SF55 Geogrid
Mechanical
P, = 3184 + N tan 21.5° < 4000
PS = 906 + N (tan 32)°
Verdura 30, 40
Synteen SF80 Geogrid
Mechanical
P, = 3370 + N tan 32.4 - 4617
Ps = 2006
Verdura 30, 40
Synteen SF 110 Geogrid
Mechanical
P, = 3107 + N tan 68.5° s 7844
PS = 2075 + N (tan 25.4)°
Verdura 50, 60
Mirafi 5XT Geogrid
Mechanical
P, = 3140
P, = 2088
Verdura 50, 60
Mirafi 8XT Geogrid
Mechanical
P, = 2858 + N tan 54.8° < 5553
Ps = 2832 + N (tan 4.6)°
Verdura 50, 60
Mirafi 10XT Geogrid
Mechanical
P, = 2502 + N tan 66:9° < 6884
Ps = 3075 + N (tan 14.9)°
Verdura 50, 60
Mirafi 10XT Geogrid
Frictional
P, = 560 + N (tan 11) < 1500
Verdura 50, 60
Mirafi 18XT Geogrid
Mechanical
P, = 2184 + N tan 70.2° s 7362
PS = 2985 + N (tan 1.9)°
Verdura 50, 60
Mirafi 20XT Geogrid
Mechanical
P, = 3326 + N tan 68.3° s 7973
Ps = 2944 + N (tan 18.6)°
Verdura 50, 60
Mirafi22XT Geogrid
Mechanical
P, = 1134 + N tan 76.7'< 9153
Ps = 2418 + N (tan 46)°
Verdura 50, 60
Synteen SF55 Geogrid
Mechanical
P, = 3003 + N tan 25.1' < 3878
PS = 1616 + N (tan 3.9)°
Verdura 50, 60
Synteen SF80 Geogrid
Mechanical
P, = 3370 + N tan 33.7° < 4617
Ps _ 1831
Verdura 50, 60
Synteen SF110 Geogrid
Mechanical
IF, = 2575 + N tan 67.2° s 7013
P, = 2259 + N (tan 15.8)°
For St: 1 poundltoot = 14.Ei Nlm.
'The equations for connection strengths are based on both serviceability connection strengths, Ps (.314 -inch deformation service criteria) and limit
state criteria, P„ and are to be used in accordance with Seciton 5.7.1 of the NCMA Design Manual when designing the connection of geosynthetic
reinforced SRWs. "N' refers to the normal load due to the weight of the superimposed units.
'The strength of each connection system is based on a block spacing of 9 inches. (The center -to -center spacing of a given Verdura or Candura
block may not exceed 27 inches.)
'The service connection strength is based on the Posi-Dura system described in Section 2.2.3, with a minimum 1 -inch -diameter PVC pipe.
Page 5 of 11
ER -5515
TOP VIEW
I
C'i
1,
FRONT VIEW
Notches in rails of Verdura
are mandatory for use where
continuous pipe/geogrid
connection are employed.
v�rFM!
� N
i
'
12.0 -
SIDE
2 a"SIDE VIEW
FIGURE 1—VERDURA30
are mandatory for use where
continuous pipelgeogrid
connection are employed -
FIGURE 2 VERDURA 4D
Page 6 of 11 ER -5515
TOP VIEW
Notches in rails of Verdura blocks
are mandatory for use where
continuous pipelgeogrid
connection are employed.
FIGURE 3--VERDURA 50
18.0"
TOP VIEW
L-1 rr-
I4IlI� i
FRONT VIEW
SIDE VIEW
Notches in rails of Verdura blocks
are mandatory for use where
continuous pipelgeogrid
connection are employed.
r~ I
o I -
L — — — — —
18 0"
FIGURE 4—VERDURA 60
SIDE VIEW
Page 7 of 11 ER -5515
For SI: 9 inch = 25.4 mm.
- Notches in rails of Verdura blocks
are mandatory for use where
continuous pipelgeogrid
connection are employed.
i
—Tl FT—f
II II i
FRONT VIEW SIDE VIEW
FIGURE 5—VERDURA 60W
17T
1
t
L _ m
4
t2'
FIGURE 6—CANDURA 25
Page 8 of 11
17 Q"
17.3"
E
S t
1 17.3"
5 �
i
L _
iY
For SI: 1 inch = 25A mm.
FIGURE 7—CANDURA35
ER -5515
1
Page 9 of 11
Pipe
Top
View
5ic"e
Posi,D
Fab.ic
Pipe
Side
View
Block
Top
View
Block
Side
View
Posi-Dura Pipe Through Posr-Dura
Fabric Connection Option
Posi-Dura Pipe Through Posi-Dara
Fabric Connection Option
FIGURE Il—POSI-DURA CONNECTION SYSTEM
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Page 10 of 11
Block
TOP
View
OptiM01 notch
at non connection
int«face
Block
Side
View
tie Fabric
FIGURE 9—WALL LAYOUT USING GEOGRID-CONTINUOUS PIPE CONNECTION
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Page 11 of 11 ER -5515
1_ INVESTIGATION OF SOIL CONDITIONS
2 DETERMINE WALL HEIGHT
3. EVALUATE EXTERNAL STABILr Y OF REINFORCED SOIL MASS
4. EVALUATE INTERNAL STABILITY OF REINFORCED SOIL MASS
5- EVALUATE STABILITY OF FACING UNITS INCLUDING CONNECTION
STRENGTH AND LOCAL BULGING
S. SOIL$ ENGINEER OF RECORD EVALUATES GLOBAL STABILITY
OF SLOPE
7. CONSTRUCT SRW SYSTEM INCLUDING GEOSYNTHETIC
REINFORCEMENT. POST -DURA REINFORCEMENT CONNECTION
SYSTEM
FIGURE 10—OUTLINE OF DESIGN PROCEDURE