Owner:
Port of Corpus Christi Authority
1305 North Shoreline Blvd.
Corpus Christi, TX 78401

Project Design Engineer(s):
Maverick Engineering, Inc.
2000 Padre Island Drive
Suite 200
Corpus Christi, TX 78416

Naismith Engineering, Inc.
4501 Gollihar Road
Corpus Christi, TX 78411

Synergy Earth Systems, LLC
26240 Equity Drive
Daphne, AL 36526

Construction Management:
Port of Corpus Christi Authority
&
Synergy Earth Systems, LLC

 

The Port of Corpus Christi Authority, in conjunction with the Texas Department of Transportation, completed the plans and contract documents for the construction of 9.6 miles of a new two-lane roadway linking Interstate 37 and U.S. Highway 181 in Corpus Christi in 2004. The project lies between Nueces Bay and the Corpus Christi Inner Harbor. The project also includes 6.2 miles of new railroad construction paralleling the roadway.

The proposed alignments of the roadway and railroad crosses over dredge disposal containment areas and deposits of naturally occurring soft soils. Synergy Earth Systems, Inc. was retained by the Port of Corpus Christi Authority to develop both the roadway and railroad embankment designs for the areas of the project involving the soft compressible soils. The cohesive shear strengths of the compressible soils ranged from 75psf to over 400psf. The compressible soils varied in thickness from 10 ft. to 50 ft. The roadway embankments were designed to accommodate HS20 highway loading conditions. The railroad sections were designed to accommodate both live and dead loads from train traffic. The live loading was specified as Cooper E88 loading as established by the American Railway Engineering Association and a specified impact loading condition of 150% of E88 loading was specified to model brake application. The design was predicated on achieving target settlement within an 18-month surcharge period at a minimum factor of safety of 1.25 during construction of both the roadway and railroad embankments.

The Synergy Earth Systems design combined the use of wick drains, surcharging and geosynthetic reinforcing to achieve the target factor of safety using the effective stress methodology. Construction of the project began in early summer, 2004 and is presently ongoing. Approximately 1,651,000 lineal feet of wick drains will be installed from working platforms constructed with biaxial geogrid over the soft surficial soils. The design calls for over 223,000 square yards of uniaxial geogrids for embankment reinforcing and about 637,000 square yards of biaxial geogrids for the construction of the working platforms, base reinforcement and railroad sub-ballast reinforcement. Piezometers and settlement plates were utilized to monitor construction response of the soft soils at the project to insure design compliance and global stability assurance.