The Challenge
A utility-scale tracker project faced extreme terrain difficulty: 44% of the site area classified as hard rock, slopes ranging 40–45%, and an initial earthwork estimate of 118,000 m³ of cut volume. At regional earthwork pricing, that represented tens of millions in civil cost risk.
The engineering team needed to evaluate multiple grading approaches before committing to a layout — and to understand how tracker pile lengths interacted with grading decisions.
The Approach
PVX.AI ran three distinct grading strategies across the same site boundary:
- Conventional grading — flatten to a single design elevation per zone, minimize slope transitions
- Bench grading — tiered platforms following major contour breaks, preserving natural drainage
- Pile-adaptive grading — optimize cut depth against pile length constraints, trading grading cost against foundation cost
Each scenario was evaluated for total cut/fill volume, average cut depth, pile length distribution, and estimated total civil cost.
The Results
The pile-adaptive approach produced the optimal outcome:
- $727K in earthwork cost savings vs. conventional grading baseline
- 70% reduction in earthwork volume — 118,000 m³ → 35,000 m³
- Average cut depth reduced from 3.0m to 0.8m
- Pile lengths held under 4m across 94% of tracker positions
- All three scenarios generated in a single design session inside AutoCAD