Experimentelle und numerische Untersuchungen zur genaueren Vorhersage des dreidimensionalen Lastabtragungsverhaltens von Hochhäusern

Abstract

Although modern FEM-programs suggest otherwise, unequivocal statements on the structural behavior of a building can never be totally achieved. N umerous practical experiences show that the accuracy .of FEM-calculations is generally difficult to narrow .down. Often, large deviations can be detected with parallel calculations. The question then arises as to how these deviations are dealt with. The increase of reinforcement or concrete often seems to be an obvious solution, but this is clone at the expense of the economics of a project. lt is therefore necessary to examine how large the static forces of constructions actually are and how they distribute themselves within the construction. As it turns out, the reason for the deviations lies in the use of linear calculation methods, which cannot show the real structural behavior with sufficient accuracy. In practice, therefore, there are always problems in determining the vertical loading transfer within constructions. Therefore, different FEM strategies have been investigated with the aim to meet the real bearing behavior as accurately as possible. At the same time, the calculation results were checked for their relevance in reality (measurement of real building loads). Due to the lack of measurements on buildings, it has not yet been possible to assess how well threedimensional calculation programs work. Against this background, two buildings (tower ML5 and tower ML3) were examined to be screened for this purpose. Within the screening, the load-bearing behavior was documented for the first time during the entire construction phase. The results of the FEM-analysis could finally be checked and calibrated with the measurement results.

Although modern FEM-programs suggest otherwise, unequivocal statements on the structural behavior of a building can never be totally achieved. N umerous practical experiences show that the accuracy .of FEM-calculations is generally difficult to narrow .down. Often, large deviations can be detected with parallel calculations. The question then arises as to how these deviations are dealt with. The increase of reinforcement or concrete often seems to be an obvious solution, but this is clone at the expense of the economics of a project. lt is therefore necessary to examine how large the static forces of constructions actually are and how they distribute themselves within the construction. As it turns out, the reason for the deviations lies in the use of linear calculation methods, which cannot show the real structural behavior with sufficient accuracy. In practice, therefore, there are always problems in determining the vertical loading transfer within constructions. Therefore, different FEM strategies have been investigated with the aim to meet the real bearing behavior as accurately as possible. At the same time, the calculation results were checked for their relevance in reality (measurement of real building loads). Due to the lack of measurements on buildings, it has not yet been possible to assess how well threedimensional calculation programs work. Against this background, two buildings (tower ML5 and tower ML3) were examined to be screened for this purpose. Within the screening, the load-bearing behavior was documented for the first time during the entire construction phase. The results of the FEM-analysis could finally be checked and calibrated with the measurement results.