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MM-T5-05
A STORM DRAIN SUCCESS
STORY:
TWO TUNNELS & A LANDSLIDE
RANDALL G. BERRY, PE
NASTT’s 2015 No-Dig Show
• Project Background / Needs
• Project Solutions - Overview
• Trenchless Methodologies
• Project Solutions - Details
AGENDA
San Ramon Canyon Storm Drain Rancho Palos Verdes, Los Angeles Co, CA
Project
Location
Pacific
Ocean
San Ramon Canyon Storm Drain
McCarrell Cyn SD
2014 NASTT
San Ramon Cyn SD
2015 NASTT
25th Street January 19, 2010
Localized 100-Year (rain gauge)
San Ramon Cyn – Background
25th Street
San Ramon Cyn
San Ramon
Cyn
Tarapaca Landslide
San Ramon
Cyn
PVDE Switchbacks
2’ - 5’ Erosion
Per year – lower
PVDE Switchback
Slide
Bluff
Erosion
Storm Blow Back
Ex. Outlet
San Ramon Cyn SD – Overview
Hydrology Map
• Watershed =
184 Acres
• Q100 =
262 CFS
48” pipe required
54” pipe installed
> 100-yr
protection
25th Street
Inlet
Structure
Slide
Location of Upstream Inlet
Historic Flood Path Proposed SD
Existing SD
100’ fire break
L = 300’
S= 38%
Pacific
Ocean
Why steel pipe storm drain mainline? • High velocities = 45 feet per second (fps)
• Sediment and cobble laden flows
No room & too steep (10%) for desilting basin
“Returning the River to the Sea” concept
Beach replenishment & less inlet maintenance
Why steel pipe storm drain mainline? • Considered pipe: RCP, HDPE, and CCFRPM
(fiberglass) pipe, but all eliminated due to poor
resistance to long-term scouring & cobble impacts
• Chose: 54” Dia. Permalok Steel Pipe w/ epoxy
coating & lining = push joint = no welding in field
• But during construction we
changed to field-welded
spiral wound steel pipe -
saved $630K split by city
and contractor ($315k)
“Slant Drain” Tunnel
Launch
Pit
“Slant Drain” Tunnel - Rotohead
80” Dia -
Front of
jacking train
Direction
Correction
Flaps
Laser
Target
Ron
Dragoo
(RPV)
“Slant Drain” Tunnel Launch Pit
80” Jacked Steel Sleeve
& 54” Jacked / Welded /
Lined Steel Pipe
• Inclinometer (Geokon
Model 6400): Between
launch pit and mobile
homes to monitor
potential horizontal
movement
• Extensometer (Geokon
Model A3, MPBX): At
25th Street crossing
over tunnel alignment
to monitor potential
vertical movement
Bluff Protection – “Geobrug”
“Slant Drain” Tunnel - Outlet
Cost savings credit #2:
Using tieback anchors
instead of soldier plies (as
was used on McCarrell
Cyn SD, at right)
Savings = $214k split for
$107k credit to city
McCarrell Canyon SD Outlet
Outlet Structure – Tieback Anchors
“Slant Drain” Tunnel - Outlet
Outlet Structure
54” Welded Steel Pipe
With Epoxy Lining
& Velocity Reducer Rings
Open
Trench
Seepage
Flow Dam
-prevents
bedding
zone
acting as
conduit to
bluff face
Upstream Inlet
Receiving Pit
Launch Pit
Long Tunnel – Rib & Lagging
L = 2,200’ S= 14%
Long Tunnel – Rib & Lagging
25th St
45’ deep
Launch
Pit
90’ deep
At Lower
Switchback
Rib & Lag Tunnel - Launch Pit
Rotohead
Multiple
Muck Carts
Rib & Lag Tunnel – Launch Pit
Train
Rotohead Emerging at Inlet Structure
Inlet Structure:
•CIDH Piles
•Grade Beam
•Soil Anchors
Completed
Inlet
Structure,
Access
Road
& Canyon
Fill
Tarapaca Slide – Gravity Buttress Fill
Head Scarp
PVDE
Switchbacks
Long Tunnel
Launch Pit
Long Tunnel
Launch Pit
Phase Begin End
PSR & Pre-Design April 2009 June 2011
Design Phase July 2011 October 2012
Bid Phase December 2012 January 2013
Construction Phase April 2013 September 2014
Line Item True Cost (% Change) Engineer’s Estimate
Original Construction Bid $15,140,000 (-1.7%) $15,400,000*
Post Award Value
Engineering** -$422,676 (-2.8%)
Project Change Orders*** +$ 731,874 (+5.6%) (1.72 % related to original design)
Final Construction Costs $15,449,198
Pre-Construction Soft Costs $950,919
Construction Soft Costs $1,350,995
Total Project Cost = $17,751,112 NOTES:
* Engineer’s (base) estimate (without a 10% contingency)
** Value engineering in pipe material & outlet structure shoring/construction yielded net credits to the city
*** Change orders included approx +$600k to enhance PVDE roadway and drainage (not in original design), +$260k in
changes related to the original design and a <$130k> credit to cover city staff weekend/OT work.
Environmental Clearances:
• U.S. Army Corp of Engineers
(Section 404 of the Clean Water Act)
• Calif Department of Fish and Wildlife
(1602 – Streambed Alteration Agreement)
• U.S. Fish and Wildlife Services
• California Coastal Commission- federal
consistency determination
• Los Angeles Regional Water Quality Control
Board - 401 certification
• City of Rancho Palos Verdes –
CEQA Lead agency
Project Team City of Rancho Palos Verdes:
• Michael Throne, PWD
• Ron Dragoo, Principal Engineer
Harris & Associates:
• Randall Berry, PM
• Liz Reyes, Deputy PM
KOA Corporation:
• Alan Braatvedt, City’s PM/CM
• Mike Jenkins, City’s CM
Ninyo & Moore:
• Jim Barton & Daniel Chu,
Geotechnical Engineering
L. H. Woods:
• Michael Ireland, Prime
Contractor
Drill Tech:
• Derek McDonald,
Tunnels/tiebacks
SFC Consultants:
• Saundra Jacobs, Environ.
BGB Design Group:
• Art Guy, Landscape Architect
KDM Meridian:
• Richard Maher, Survey &
Movement Monitoring
THE END
Southern Chapter APWA 2014
“Project of the Year” Award
“Innovation” Category
National APWA 2015
Small City “Project of the Year” Award
“Disaster / Emergency Repair” Category
