SSC Completes Auger Bore Project in US Virgin Islands

Operating under the name SSC USVI Boring- Drilling- Vacuum Excavating LLC, SSC recently completed four 120' long auger bores for HOVENSA, a world-class merchant refinery located in St Croix, USVI.

Hovensa, a joint venture between a subsidiary of Hess Corporation and a subsidiary of Petroleos de Venezuela, S.A. (PDVSA), operates one of the most modern refineries in the United States. With crude oil processing capacity of 700,000 barrels per day (BPD), Hovensa is one of the largest in the world.

The main refinery was constructed in the early 1960's, and sits atop a dredged ocean floor. Four of the original main lines, which pump crude oil from holding tanks to the main refinery, needed updating, requiring the installation of 4 new steel wall casings. Along the 120' bore path, each of the 2 (48") steel casings, and 2 (30") steel casings had to pass through at least six different soil types ranging from coral to sticky clay. This initially proved challenging for SSC because of the lack of binding materials in the soil to prevented cave-ins. But with over 38 years of experience in all soil types SSC was able to overcome these challenges using time tested technology, finishing the project eight days early with line and grade intact.

"This contract was very exciting for us," said Arvid Veidmark, III, co-owner and senior estimator for SSC, "because it demonstrates how our work and dedication to the field of trenchless technology has gained us the respect of engineers and contractors worldwide."

BMTA TRENCHLESS ALTERNATIVE

For applications where line and grade are critical and tunnel diameter is greater than 48 inches. Cutting head is individually powered, separate from the power supply of the boring machine itself. Electric over hydraulic controls provide maximum controllability of line and grade. The boring machine provides the BMTA with thrust and auger spoil removal.

CASE STUDY:

Project: Santan Freeway Siphon
Contractor: Haydon Building Corp.
Sub Contractor: Specialized Services Co.

Overview: Installation of a 60" OD X .500" wall steel casing and subsequent installation of a 30" RGRCP diverson line to divert irrigation water from a retention basin to a pump station.

Challenge: Length of bore. Undisclosed median backfilled with 24" long chunks of concrete.

Solution: Hand excavated in front of the 60" cutting head until the limits of the median were met, then open cut the median and pushed the casing on through, resumed boring.

Design:
· Diameter - 60" OD
· Length - 502'
· Gravity - grade critical
· Existing Utilities - 48" storm drain below 60" casing.
· Depth - shallow with 4.5' cover under pavement.
· Soil conditions - hard caliche.

Comparison of Trenchless Methods:
Auger-hard to control grade for this length
HDD-impractical for this application
Hand Tunnel-too slow 4' to 6' per day
Pipe Ramming-too costly for this application

Construction Phase:
· Setup shoring in bore pit excavated by GC.
· Setup BMTA in bore pit.
· Install 502' OD 60" steel casing.
· Attach casing spacers to the 30" RGRCP.
· Push through the 30" RGRCP.
· Fill the annular space with chip.
· Brick and mortar the ends of the casings.

More trenchless technologies to come in the next issue!

Damage Prevention Conference
December 5 & 6, 2007 Las Vegas Hilton

December 5, 2007

9:15 AM Designing a Successful Trenchless Underground Construction Project.

Arvid Veidmark, III, Owner/Estimator

Specialized Services Company

A veteran in the trenchless arena provides step-by- step instructions on how to implement and utilize the latest technology & methodology to limit disruptions, reduce costs, minimize design changes, and eliminate environmental issues.

2:15 PM Dealing With Those Government Entities Who Won't Let You Pothole Their Roads.

Arvid Veidmark, III, Owner/Estimator
Specialized Services Company

Walt Kelly, Damage Prevention Consultant, Walt Kelly Enterprises

Some governmental units will grant a permit to bore under a road, but forbid potholing where the drill will pass the high-pressure gas, the high voltage electric, or the fiber optic. They may suggest to blind-bore just like all the others have done. Hear some effective ways to deal with this situation.