Louhintahiekka involved in the construction of Oak Hospital

Louhintahiekka started the earthworks for Tammisairaala in the spring of 2021. According to Aapo Lahtinen, the company’s CEO, the project was both challenging and intriguing.

"This was a unit-price contract where over 40,000 cubic meters of soil were excavated, and another 40,000 cubic meters of rock were blasted to a depth of up to 18 meters. The difficulty was increased by the fact that the blasting took place in an urban area, right in the heart of Meilahti, Helsinki," says Lahtinen.

Blasting in a residential area requires extraordinary precision and vibration restrictions were strict.

"It was crucial to carefully protect the blasting fields. Charging and drilling were meticulously planned and adjusted as the work progressed to ensure the vibrations remained within the permissible limits while keeping the work as cost-efficient as possible," he explains.

The project included a wide variety of rock excavation tasks such grouting, bolting, wedging, dislodging, and constructing a five-meter-long tunnel in the middle of the excavated rock wall.

"The hospital site was challenging. Part of the land was on solid rock, but the rock area dropped steeply, turning into clay-like soil, which required significantly more drilled piling than initially planned."

In addition to the actual blasting and piling work, Louhintahiekka was responsible for the building’s underground piping, street-level infrastructure, and backfilling. Due to space constraints, smaller machines and conveyor belts were used for backfilling operations.

Louhintahiekka completed its part of the project in early summer 2024, and the hospital is scheduled to open in spring 2025.