House of knowledge
(Library, VHS, market hall)
Willy Brandt Place 1-3, 44787 Bochum
Shell construction, steel construction and carpentry work
The content of this tender is the complete structural work to be carried out within the existing building and the new building in the inner courtyard. It should be noted that the telecom area remaining in operation is located in the part of the east wing, on the ground floor and basement. The condition at the start of the order can be described as follows: The existing building has been largely gutted and part of the inner courtyard façade was demolished in advance. The existing façades to be preserved have already been secured by previous safety measures. These safety measures (steel structures) will be dismantled in the ongoing construction process of this order and must therefore be taken into account at the beginning of the shell construction measures (construction of ceilings including roof trusses and façade supports).
For the further structural measures, the excavated soil in the inner courtyard will be further deepened by approx. 1.20 m and continued into the existing building. For this purpose, an excavation of the earth and a dismantling of the safety berms with a volume of approx. 6,260 m3 (mostly cohesive and fine-grained soils, partly coarse- to mixed-grained fillings) must be carried out. Attention must be paid to vertical offsets of the building floor due to different floor slab thicknesses. In addition, the excavated material cannot be reused or temporarily stored, which is why direct disposal must be provided. A profiling of the subsoil with regard to the installation of pipes for the purpose of the geothermal probes must also be provided. In the course of the remaining excavation within the existing building, floor slabs with a total area of approx. 1,050 m2 as well as MW and STB walls with a total mass of 90 m3 must be dismantled and disposed of. In addition, in the course of excavation, underpinnings are to be carried out in in-situ concrete both below the outer walls adjacent to the excavation pit and within the existing beams, successively using the pilgrimage step method.
In the course of the foundation work and the construction of the basement, the construction ramp will be dismantled and disposed of. The backfill of the working rooms is 1,850 m3.
After dismantling the façade stabilizations and the girder plank construction, further earthworks will be carried out with regard to the following measures:
For the construction of the ventilation shafts in the inner courtyard, an excavation of approx. 1,440 m3 and a backfilling of the workspaces of approx. 1,060 m3 must be carried out. For the building entry on Viktoriastraße, an additional excavation of approx. 200 m3 as well as a backfilling of the working space of approx. 130 m3 must be provided. Furthermore, for the insulation and waterproofing measures of the existing walls in the basement, excavation and backfilling work will be carried out on the street side with an approximate total volume of approx. 690 m3 and by means of shoring.
The wall areas to be sealed are approx. 600 m2, on part of this area perimeter insulation is applied to the existing cellar walls.
The shallow foundation of the new building, both in the inner courtyard and in the north wing, is largely carried out with a 120 cm thick floor slab and occasionally with floor slabs of lower slab thicknesses made of WU concrete. The total volume is approximately 3,450 m3.
Among other things, prefabricated elements are to be installed in the construction process: 45 pcs prefabricated stairways with running widths of approx. 1.20 m to approx. 1.99 m and number of steps from 6 pcs to 13 pcs, 3 pcs inclined flights of stairs with running widths of approx. 2.90 m to approx. 9.50 m and number of steps 12 pcs, angle elements (seat steps) with leg length height approx. 0.66 m to depth approx. 0.90 m, Prefabricated beams stepped cross-section of approx. 0.10 m2 to approx. 0.33 m2, spun concrete columns d = 45 cm and total running metres of approx. 690 m in partial lengths of approx. 2.79 m to approx. 17.18 m and filigree slabs width approx. 1.50 m, total area approx. 328 m2.
The slabs in this construction project are largely made of wood-concrete composite slabs, 95% of which are manufactured as prefabricated wood-concrete slab components in the factory and 5% as a board stack slab with in-situ concrete. In the work of the HBV ceiling, both the support of the ceiling, connection to the existing masonry and the connection to the Deltabeam composite girders must be taken into account. In total, the area of the HBV ceilings is approx. 7,850 m2 and the length of the Deltabeam composite girders is 1,122 m. During the execution, care must be taken to ensure that no large point loads are transferred to the HBV ceilings, so support scaffolding must be provided to transfer the overlying loads. For the production of in-situ concrete slabs and beams with heights >3.5m, the required shoring of design class >A must be designed and verified. Furthermore, individual working platforms and scaffolding will be erected on the facades in order to be able to install the façade support and to be able to carry out overhead work. Several steel structures are to be erected. On the existing beams, part of the gable roof is made of approx. 33.30 t steel, the steel structure Pergola Skydeck is approx. 9 t, and beams of different profiles are also to be installed. On the other hand, the ceiling above the Telekom is supported by a steel structure with a total weight of approx. 18 t. In the new building, a new canopy is planned, which consists of approx. 2 t of steel.
During the carpentry work, a new roof truss (gable roof with several dormers) is made. For this purpose, approx. 80 m³ of wood must be used. In addition, a special shovel construction is produced above the technical center, which serves as an upper support for the rafters.
Finally, the new building in the inner courtyard is to be provided with a terraced roof made of reinforced concrete, which has a total volume of approx. 824 m3 on an area of approx. 2,440 m2
Aggravating circumstances are given when replacing the ceiling over the ground floor - telecommunications area. The Telekom division will be in operation during the entire construction project. On the part of Deutsche Telekom, a protective roof construction is planned in the room, but increased care is still required in this area.