Requested research

Literature review: Assess existing research on the seismic behavior of monolithic earthen structures, comparing rammed earth to reinforced brick and block masonry systems.

Structural analysis: Evaluate the role of vertical and horizontal reinforcements in rammed earth structures. Do they compromise critical sections and weaken the walls, or do they enhance the overall seismic performance?

Key parameters: Define all factors influencing the seismic performance of this earth technique, such as wall configuration, overall dimensions, reinforcement detailing, material and mechanical properties, earth composition, and additives to the earth mix.

Practical application: Design, model, and analyze a prototype rammed earth house suitable for seismic regions. Determine design limitations and structural safety margins, based on minimum needed material and mechanical strengths.

Background: rammed earth

Earthen construction remains to be widely practiced globally, including in seismic-prone areas. Yet scientific literature on its seismic behavior is still limited. This project focuses on loadbearing monolithic earth structures — of which the most well-known are rammed earth and cob.

Rammed earth walls are built by placing successive layers of earth into formwork and compacting them through tamping. This technique is particularly well suited for mixtures with a high proportion of sand and gravel, which can be further stabilized with lime or cement. Optimizing the relationship between dimensions, wall thickness, and overall form can significantly enhance the seismic resistance of rammed earth buildings.

A common reinforcement method involves integrating horizontal bands and vertical steel bars into the walls. However, an important question arises: do these reinforcements strengthen the structure, or do they compromise its monolithic nature and reduce overall performance? Additional areas of investigation include long-term maintenance, the effects of moisture, the use of stabilizers and fibers in earth mixtures, and the potential benefits of wall tensioning.

Further action

This assignment is part of a broader research program to evaluate and improve the seismic performance of earthen structures, alongside studies of stabilized earth blocks and interlocking stabilized earth blocks.

Interested? For more information, or to explore this as a final-year thesis opportunity, send us an email to schedule a meeting.