SERA AIMS - Shake Table Test and Blind Prediction Competition

This experiment investigated the seismic behavior of stone masonry building aggregates, focusing on the interaction between adjacent structural units connected by mortar without interlocking stones. Such configurations are common in historical European city centers and present unique challenges in predicting seismic responses.

Testing Methodology:

A half-scale masonry aggregate was constructed, comprising two units:

Unit 1: Single-story, U-shaped layout with plan dimensions of 2.5 × 2.45 meters and a height of 2.2 meters.

Unit 2: Two-story, rectangular layout with plan dimensions of 2.5 × 2.5 meters and a total height of 3.15 meters.

Both units were built using double-leaf irregular stone masonry with hydraulic lime mortar, replicating traditional construction techniques. The units were connected by mortar joints without interlocking stones, simulating weak interfaces typical of historical aggregates.

The specimen was subjected to incremental seismic loading on a shake table, with input motions derived from the 1979 Montenegro earthquake (Ulcinj-Hotel Albatros station). The testing sequence included unidirectional and bidirectional excitations at increasing intensity levels, allowing for the observation of damage progression and interaction effects between the units.

Outcomes:

The experiment provided valuable insights into the seismic performance of masonry aggregates:

Damage Mechanisms: Cracking and separation at the interface between units were observed at lower intensity levels, progressing with increased loading.

Interface Behavior: Bidirectional loading significantly influenced the interaction between units, leading to frictional effects and pounding.

Structural Response: A soft-story mechanism developed in the upper story of Unit 2 during higher intensity runs, highlighting vulnerabilities in multi-story configurations.

Data Reusability:

The collected data, including acceleration records, displacement measurements, and detailed damage observations, are invaluable for researchers and engineers. They can be used to:

Validate Numerical Models: Enhance the accuracy of simulations predicting the seismic behavior of similar structures.

Develop Retrofitting Strategies: Inform interventions aimed at improving the seismic resilience of historical masonry buildings.

Advance Seismic Assessment Methods: Contribute to the refinement of guidelines and standards for evaluating the seismic performance of masonry aggregates.

By providing empirical evidence of the complex interactions within masonry aggregates under seismic loading, this experiment aids in bridging the gap between theoretical models and real-world behavior, ultimately contributing to the preservation and safety of historical structures.