Location: Mojave, CA
Time Frame: 2010/201

Construction and installation of 190, 3.2MW wind turbines and associated infrastructure including collections system, 2 substations, operations and maintenance buildings, several communication towers, and over 40 miles of roadways.

Scope of Services

NOA provided Quality Control during construction for the purpose of verifying the project met approved plans and specifications. NOA services included inspection of foundation excavations of turbines, substations, Met towers, operations and maintenance buildings, backfill testing around turbine foundations and transmission lines, reinforcement inspection of turbine foundations including formwork and grounding, concrete testing of all other foundations, grout testing at bases, subgrade testing and proof rolling of roadways and crane pads. NOA was also called upon to provide geotechnical consulting on alternative erosion protection at 22 of the turbine foundations. The initial design for foundation protection consisted of a slab on grade concrete apron with a 6 feet turndown footing at the perimeter in order to protect the foundation during a large storm event. NOA developed a soil/cement design that used on site materials to construct a soil cement apron with a thickened edge. This alternative design was developed by NOA and verified in the field during construction. The NOA alternative design resulted in a cost savings of more than 300% and also provided a more ‘green’ solution, in utilizing the on-site soils.

Challenges

The project schedule had strict time constraints that needed to be met by the contractor. This in turn required NOA to provide daily reporting of inspections and laboratory testing. The laboratory testing was so critical that often results needed to be available by 7am that morning. Over 100 concrete compressive strength tests were performed every day. At times, 3 bases were being poured during one shift with several pedestals following the next shift. This required a relatively large NOA staff on site who worked seamlessly together and with the contractor and owner. These strict timelines allowed NOA to develop an improved way to transfer data to multiple parties. NOA developed a file transfer area on the NOA website to upload reports and testing results every day. All parties involved in the project could access data and run a search, dependent on date and type of inspection, for the needed documents and download at their convenience.

Skills Demonstrated

NOA developed a timely reporting and file transfer process between all parties. Geotechnical consulting demonstrating project savings and ‘green’ alternatives. NOA staff worked seamlessly as a team with all others to complete the project within the challenging and limited schedule. Excellent coordination and communication between NOA, contractor and owner.