Integration of the historic steel structure in line with conservation guidelines

Alongside the double M gate, the golden spire with the red star on exhibition hall 12 is one of the landmarks of the Alte Messe Leipzig. The transformation of the approximately 200-metre-long structure into a versatile building complex is one of the largest and most challenging construction projects currently underway in Leipzig. To this end, the hall has been largely demolished down to ground level. In accordance with the requirements of monument protection, the northern and southern porticoes as well as eight frames of the historic main structure – a three-aisled, riveted steel construction dating from 1924 – will be preserved.

The first construction phase, which was completed in 2019, saw the rehabilitation of the northern head building in accordance with monument protection guidelines and its conversion into one of the most modern city archives in Germany. Since mid-2023, a high-quality four-storey office and archive complex has been under construction in the second phase. Covering an area of around 50 by 85 metres, the new building will house an innovation centre mainly for biotechnology companies. The client for this third and final phase of construction is LGH Leipziger Gewerbehof GmbH & Co. KG.

Complex construction pits and securing existing structures require sensitive work

The construction pit is being excavated in sections to a depth of up to 4.8 metres and mostly sloped. As an underground emergency power supply will protrude beyond the building line of the new structure, the PORR special civil engineering team is securing the drop in ground level in this area with a clamped girder pile shoring system. Along the portico, the existing structure will be underpinned with 1,400 cubic metres of jet-grouted elements. Steel bracing as well as back anchoring with 35 strand anchors will provide additional stability; in a section where anchoring is not possible, a bracing structure will take over this function. The historic individual foundations of the existing steel frames are also being reinforced and reduced in size with DSV underpinning.

The installation of a closed water drainage system with surface drainage is also part of the special civil engineering services. Monument protection, cohesive subsoil and numerous unknown remains of old buildings require the utmost technical care. ‘The historic structures must not be damaged by vibrations. Lifting caused by the introduction of the cement suspension must be avoided at all costs. Our team masters these challenges every day with experience and precision,’ praises Patrick Günther, Technical Branch Manager at PORR Spezialtiefbau Berlin.