Project Scope

The project scope was to conduct geotechnical borings over water to peform field testing and soil sampling for the design of the proposed roadway improvement by land reclamation.

Geotechnical Laboratory Testing

moisture contents, index testing, sieve analysis, soil classification tests, rock core compressive strength tests, direct shear on soils, CU triaxial tests with pore water pressure measurements.

Drilling and In Situ and Field Testing

Field work consisted of over twenty (20) over water test borings with SPT and undisturbed (Shelby tube) sampling and HQ size rock coring. Boring depths ranged between 40 ft to 90 ft below water level.

Challenges

Over water geotechnical drilling has a very low barge movement tolerance for obtaining high quality undisturbed soil samples and wireline HQ rock cores.

Solutions

Using knowledge gained from marine projects in the Caribbean region, our team customized a sectional barge system assembled to form a stable platform to allow drilling and rock coring. A tree point anchor system was used to reduce potential displacements. Also two (2) steel pipe spuds where fitted on the side of the barge to further stabilize the barge. Most core runs for the project had over 95% recovery, even in fractured rocks having RQD of 0. The project was successfully completed ahead of schedule and under budget.