Höchst Industrial Park, Frankfurt am Main

The history of the Höchst chemical and pharmaceutical facility site in Frankfurt am Main began in the year 1863 with a small tar dye factory. From 1883, the growth of the company later known as Höchst AG into a global operation was driven by the manufacture of medicines. In 1997, after a restructure, the head office of the company was moved to the Höchst industrial park.

Ongoing investments have been made in the 460ha property over the years, but over 150 years of construction activities and a legacy of production-based pollution have still managed to leave their mark in the soil. The team had to overcome quite a number of challenges in executing the pile foundations for a new building expansion on the site. In spite of this, however, 182 top-quality Fundex piles measuring 44/56cm in diameter were manufactured on schedule.

High safety standards on company premises

Our team required SCC (Safety Certificate for Contractors) certification in order to work on the premises of this industrial client, and PORR Spezialtiefbau is certified in accordance with the SCCP checklist, 2011 version. Works on the company’s premises had to be carried out during ongoing operations. Our well-trained specialist personnel successfully met the high requirements for health, safety and environmental protection, and completed the project with flying colours.

Perfectly coordinated work processes

After the demolition of an existing building, the site was refilled with sand, gravel and dirt. However, various complete and remnant foundations in various states remained beneath this layer.

In view of the expectation that some areas would be contaminated, the team decided to use Fundex displacement piles in accordance with DIN EN 12699 for the foundations, as no soil is extracted with this method. Limited space and existing supply lines also necessitated a particularly cautious and foresighted working method. In the northern section of the construction site, for example, where the new structure came close to an existing building, piles were inserted into a gap between pipe bridges and hydrogen tanks. Plenty of experience and sure instincts were required to successfully operate the large drilling equipment in these circumstances. Pile manufacturing works were conducted in parallel with exploratory drilling, which meant that working routes, storage areas and surveying markers had to be precision planned in a limited space.

Contact drilling to explore old foundations

A total of 197 contact drilling holes were bored before works began, in order to establish the location of any old foundations. Once the pile layout had been adapted accordingly, pile insertion points for rubble clearance drilling were determined. Solid obstacles cannot be penetrated during the manufacture of displacement piles, so the up-to-5m-thick reinforced concrete foundations located within the site soil had to be pre-drilled with a separate apparatus. In addition, the site soil was found to be extremely abrasive and heterogenous. A workshop was erected on the site for the maintenance and preparation of drilling equipment, to avoid any delays resulting from increased wear of the equipment.