Case Study: Kajima Corporation achieves 150% increase in earthworks productivity with Trimble GCS900 Grade Control and VisionLink

Contractors Kajima and Tomijima Increases Earthworks Management Productivity by 150% for Oitagawa Dam Build with Trimble Grade Control

Kajima Corporation and subcontractor Tomijima Construction were tasked with excavating and preparing the mountainous Oitagawa Dam site in Kyushu, Japan—a large, high‑slope rock‑dam project requiring precise grades, heavy rock breaking and strict safety measures. They needed to speed up excavation, reduce on‑site staking and survey time, and keep crews out of harm’s way while moving large volumes of material for the dam foundation.

Working with NTJV, the team equipped excavators and dozers with Trimble GCS900 grade control, Site Positioning (SPS) Essentials Kits and SPS620 total stations, and used VisionLink for site‑wide monitoring and data management. The solution delivered a 150% increase in earthworks productivity, 90% less staking, an 80% reduction in daily data prep time (from 2.5 hours to 30 minutes), and enabled moving 1.39 million m3 of material more safely and reliably.

Kajima Corporation