Department of Homeland Security Project:
Pre-Engineered Bridge San Luis, Arizona at the Mexican Border

By John H. Berry, Manager CETCO Construction Drilling Products
Co-Authored By Michael Hagy, PACO Equipment

Background

The job was a Department of Homeland Security Project in the border town of San Luis just south of Yuma in Southwestern Arizona.

The project consisted of building a bridge over the Sanchez Canal in order to provide U.S. Border Patrol agents better access to the border fence area to prevent illegal entries into the U.S.

The Challenges

• Soil Conditions

Drilling through layers of gravel and sandy soil were conditions likely to create excessive fluid loss.

• Water Chemistry

High hardness and high chlorine content were present in mix water, which impact effectiveness of polymer drilling fluid additives.

• Location

The remoteness of the location made trucking water in a time consuming and expensive project, therefore minimizing water loss was a key objective of the project. Another factor in the desert area is heat. Temperatures climbed to around 117 degrees during this project, which can impact polymer viscosity.

Solution

Shore Pac^® drilling fluid yields into a very viscous clear liquid that holds the hole open by hydrostatic head pressure and forms a gelatinous membrane along the side walls of the excavation or hole. It also assists in keeping the spoils on the auger. Shore Pac has been specifically designed and created for the foundation drilling marketplace. Shore Pac typically is less complicated and easier to use than competitive products, and can require half as much polymer for equivalent results.

CETCO also provides additives, such as De-Chlor™, Stone Stop™ and Sand Sealant™ to develop customized formulations to meet site-specific conditions, and the expertise and support of a highly trained technical staff to help design these systems.

Project Implementation

The mix water was pretreated with De-Chlor and Soda Ash to optimize water chemistry. Once the water was properly treated, Shore Pac^® dry granular polymer was added to the mix water through a venturi mixer installed at the discharge end of the hose. CETCO additive packages were utilized in combination with Shore Pac polymer to minimize fluid loss. The entire project went according to plan and finished on schedule.

Results

All involved were pleased with the results. Jim Surdyk, Project Manager at CASE Foundations said “Shore Pac slurry allowed us to drill two holes a day and leave them open all night, even though the soil was loose gravel. We were able to control the slurry loss with the CETCO additives Stone Stop and Sand Sealant so we could get a good night sleep. When we tapped the hole in the morning we still had little settlement over-night.”

The Shore Pac Polymer Slurry System has proven itself repeatedly on many high profile bridge and construction projects and has gained nationwide and international acceptance. In many cases the SHORE PAC Slurry System has proven to cut operational slurry costs on projects from 25% to 50% compared to competing brands.

CETCO Construction Drilling Products has professional geologists, hydrogeologists, and slurry engineers who assist estimators and project managers by designing, complimentary Site Specific Slurry Programs for polymer or bentonite drilling. Slurry engineers are available to assist on your project with slurry construction, managing slurry operations, conducting testing procedures, training personnel and conduct slurry schools.