Lightweight masonry basement walls under earth pressure

• Applicants: Dr.-Ing. Joachim Hannawald; Professor Dr.-Ing. Martin Ziegler
• Subject Area: Structural Engineering, Building Informatics and Construction Operation ; Architecture, Building and Construction History, Construction Research, Sustainable Building Technology ; Geotechnics, Hydraulic Engineering
• Term: from 2017 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 325176862

Masonry is particularly suitable for the execution of basements, due to its building physical properties. However, the increasing demands on the building physics of wall materials have caused a mostly strong reduction of the unit strength resulting in a lower load bearing capacity of masonry walls. The design of basement masonry is based on old models, that do not consider an improvement of the unit thermal insulation properties. The current design is inconsistent concerning the modelling and in particular does not take into account the interaction between wall and soil.The prevailing design methods are on one hand quite conservative so that especially in the case of earth pressure stressed masonry walls with low compressive load the verification cannot be fulfilled, however a sufficient load bearing capacity is completely given. On the other hand, work spaces are filled much earlier and the soil is compacted with increasingly heavy compaction equipment, which has led several times in the past to damages. The objective pursued by this research approach especially takes into account the interaction between wall and soil and the resulting earth pressure, which depends on the load-dependent wall stiffness, the wall geometry and the soil compacting method. Apart from this it considers the moment redistribution capacity of nonlinear material behaviour. With a combination of experimental studies and analytical/numerical analysis a physically consistent model shall be developed. The currently existing model uncertainties in the masonry basement wall design will be thereby eliminated.

• DFG Programme: Research Grants
• Major Instrumentation: Optische Messtechnik
• Instrumentation Group: 5430 Hochgeschwindigkeits-Kameras (ab 100 Bilder/Sek)
• Co-Investigator: Martin Feinendegen