New approaches for the realistic dimensioning of masonry structures under horizontal loadsCopyright: © LBB
Modern masonry structures made of brick masonry have to meet the architectural requirements for transparency and user flexibility, but at the same time have to be optimally designed in terms of statics, energy, noise and fire protection. This leads to the great challenge of realizing floor plans with as few shear walls as possible with new masonry products that have been optimized in terms of building physics. Due to the complex interplay of the listed requirements, the static design of brickwork structures under horizontal loads can often only be implemented in the limit area of the verification or with the additional installation of reinforced concrete walls. The main reason for this is that, although the construction method has continuously developed with new innovative products and processes, no substantial progress has been made overall in the calculation and dimensioning concepts. The arithmetic verifications of masonry structures are still carried out using linear arithmetic models that are too conservative, in which shear walls are shown in simplified form as replacement shear bars. Essential interactions such as normal force redistribution, ceiling restraint effects and load redistribution options are not taken into account. With the stresses determined in a simplified manner, verifications are carried out at the wall level in specified dimensioning sections, whereby the resistance of the wall is determined from the minimum of the load-bearing capacities for bending, shear with frictional failure and shear with stone tensile failure.
The scientific-technical problem to be solved in the project consists in the development of new approaches for a more realistic calculation and dimensioning of brickwork structures. This requires a new, more holistic approach in which the load-bearing and deformation capacities at the wall level are closely linked to the calculation at the building level. The rigid separation of a simplified calculation model and a dimensioning at wall level has to be abandoned in order to capture the boundary conditions in the building more realistically.
The challenge of the project is to find a comprehensible and practicable way to develop the structural reserves with a reasonable calculation effort and to make them available in practice. The problem is well known in practice and repeatedly the subject of intensive discussions at specialist conferences and in standards committees, but it has not yet been resolved.