PICTURE OF (SITE)
CAPSTONE TEAM WHO WE
ARE (MEMBERS SKILLS)
MAQUIGR TEAM BEYOND
SHOWS FRACTURED ROCKS
PICTURES DISPLAYED
RETAINING WALL DESIGN
S LO P E S TA B I L I T Y O N U S - 1 8 9
MAQUIGR ENGINEERING
Matthew Hakes, Quinton Taylor, Greg Hanks
Site Evaluation
SITE 1 IS FEATURED ON TOP
SITE 2 ON BOTTOM
Site 1
NOTICE:
WATER LOCATION
Site 2
TEMPORARY SOLUTIONS
LOADS CAUSED BY ROAD
Considered Solutions
SHEET PILE
PROS RAPID CONSTRUCTION
CONS
SHALLOW ROCK MAKES IT
IMPOSSIBLE TO DIG IN DEEP
ENOUGH TO GET MOMENT
Gabion
Tieback
Sheetpile
Tieback
Shotcrete
Soil Nail
Analysis with SnailPlus
Assumptions made:
Two different soil types
• Gravel/Sand
• Bedrock
Loading
• Temporary Max: 700 psf from construction
• Permanent Max: 200 psf from traffic
Morgenstern-Price
• General limit equilibrium (Moment-force)
FHWA factors of safety used
Analysis with SnailPlus
Under construction loading conditions
Design section
No. 4
No. 3
Calculation
Calculation
successful
Calculation
successful
FS Slope
Fmax Nails (k)
Fmax Nails at
Head (k)
1.347
17.3
17.3
0.296
0.89
0.286
2.155
6.8
6.8
0.117
0.353
0.113
FS Slope
Fmax Nails (k)
Fmax Nails at
Head (k)
1.579
14.9
14.9
0.257
0.856
0.275
3.07
5.5
5.5
0.094
0.331
0.09
STR Check Nails STR Check Plates STR Check Facing
Under normal traffic loads
Design section
No. 4
No. 3
Calculation
Calculation
successful
Calculation
successful
STR Check Nails STR Check Plates STR Check Facing
Final Design
INITIAL CONCEPTION OF
WALL SHAPE
CREATED SLOPE IN AUTO
CAD
• 10ft from road
edge
• Average
height, 6ft
• 120ft in length
• Max height,
13ft
• 17 Total Soil Nails
UNIFIED DESIGN 1/2 THE
DISTANCE FOLLOW SLOPE
OR WHAT
OPTIMIZED FOR
CONSTRUCTION
Phase 1
Site Preparation
•Conducted during low traffic flow
•Close southbound lane
•Flaggers to direct flow of traffic
through single lane
Environmental Impact Reduction
(3 lines of defense)
•Excavated 5ft bench
•1ft silt fence installed 20ft below
excavation line
•Exposed Shoreline
Phase 2
Excavation Slope Preparation
•5ft bench approximately 10ft out
from edge of the road
•Excavation of 1,000 cubic feet
•Soil relocated to holding site
Phase 3
Soil Nail Installation
•Williams Geo-Drill Injection Anchor
System with rotary percussive drilling
•In case of hitting hard rock, a
Polyester Resin Rock Anchor System
may be used
Phase 4
Prefabrication of Rebar Cages
Phase 4:
•Constructed offsite due to limited space
•75 year design life, hot-dip galvanizing
Phase 5
•Challenge will
be mobility and
visibility of
excavator
•Guided into
place by
multiple workers
located on
bench
Installing Rebar Cages
The key to the project was contstruction speed
8 in mat
Number 6 rebar
Tied together
Bring in on flat bead and then drop in excavator secure them in
place
Phase 6
Shotcrete
•Two step process using wire mesh
as backstop for shotcrete
•First day application spraying
towards the road, second day
other side is applied
A problem (wall needs concrete)
solution we could pump it with shotcrete
Bench was created for workers to stand on
No wall – wire mesh 2 sided
Phase 7
Installing Drainage System
Phase 5:
•Composite Drainage system
•Drainage system includes: geosythetic filtered
fabric and molded plastic core
Phase 8
Anchor to wall Attachments
•Bearing plate, hardened washers, hex nut,
and Geo-Drill Injection Anchor
•75 year design life, galvanizing bearing
plate and hardened washers and capped
with a steel tube filled with cement grout
Phase 9
Backfill
•Using the soil from the excavation,
backfill at 8-12in lifts
•Compact soil with plate compactor
attachment while avoiding soil nails
•Increased bar size to improve bending
strength in the case of accidental
contact with compactor
Phase 10
Phase 11
Capping
Cleanup
Phase 10:
•Last 4-6in of backfill will be filled with
cement to cap off the retaining system
•Reduce permeability of surface and
prevent corrosion
Phase 11:
•Remove silt fencing and any loose
material
•Add soil to bench to create a more
natural slope
•Application of hydroseed to slope to
promote vegetation growth
Time and Cost
Estimates
Days
Plans & Surveying
Permits & Fees
Construction Loans
COST
17
For this Project we will assume that Planning and
Surveying, Permits and Fees and Construction Loans are
taken Care of at this point. The Schedule will be 17 Days
1
1 2
Phase 1
Staging area
Silt Fencing
Moving Baricades
Traffic Control
Laying gravel
Construction Signage
3
4 5
6
7 8
9
10 11 12 13 14 15 16 17
THE FEDERAL HIGHWAY
ADMINISTRATION
CHARCTERISTICS THAT COST
$$$
Phase 2
Staking
Excavation
Soil Removal
Phase 3
Marking
Soil Nail Instalation
drilling
add section
grouting
capping
LOCATION, MATERIAL,
NIGHT TIME ECT
Phase 4
Delivery Rebar, Ties
Cutting Bending rebar
tieing rebar
Installing wire mesh
loading for transit
SCHEDULE
Phase 5
Drainage Fabric
Drainage Piping
Phase 6
Marking Location
Leveling Compacting base
delivering from staging
dropping in place
In place fabrication
securing soil nails
Phase 7
Shotcreting walls
Phase 8
Attachmen plates
Phase 9
Load for backfill
Transport backfill
Place Backfill
Compact 10" lifts
HOW WE CAME UP
INTEGRATING PHASES TO
OPOMIZE TIME
Phase 10 Form for concrete cap
Pour concrete
Phase 11 Cleanup
Removing Traffic devices
•Cost estimates are based on the FHWA pricing graph and scheduling was created in 11 phases
Conclusion
A soil nail retaining system is the best option for this project
•Adaptable – Depending on what is encountered during construction this design can easily be
modified to meet the needs of the project
•Cost Effective – With little excavation near the road, a temporary wall will be unnecessary
•75 Design Life – Simple methods that can be implicated to increase design life