Seismic Stabilization of Historic Structures (1990-1996)
 

A collapsed wall at the Andres Pico Adobe after the 1994 Northridge earthquake. Developing a methodology for seismic strengthening of adobes such as this historic California structure was part of the GCI's research effort during the 1990s. Photo: Dr. E. Leroy Tolles, ELT & Associates.

An unretrofitted, one-fifth-size scale model of an adobe structure, prior to being subjected to simulated earthquakes on a computer-controlled shaking table at Stanford University. Photo: William S. Ginell.

The same unretrofitted model as above after being subjected to simulated earthquakes on the shaking table. The gable end walls collapsed. Photo: William S. Ginell.

A detailed view of nylon straps, fitted onto the walls of one of the scale models. The straps, one of the techniques developed for seismic stabilization, assist in reducing the shifting of adobe blocks during a quake. Photo: William S. Ginell.

A retrofitted, one-half-size scale model of an adobe structure, prior to being subjected to simulated earthquakes on a computer-controlled shaking table at the Institute of Earthquake Engineering and Engineering Seismology (IZIIS) in Skopje, capital of the Former Yugoslav Republic of Macedonia. Photo: William S. Ginell.

The same retrofitted model as above after being subjected to simulated earthquakes on the shaking table at IZIIS. The retrofitting prevented serious damage to the structure. Photo: William S. Ginell.

The 14th-century Byzantine Church of St. Nikita, located near Skopje. The church was selected at a prototype for modeling and testing of retrofitting techniques for Byzantine churches. Photo: William S. Ginell.

The large-scale model of the Church of St. Nikita, constructed to test seismic stabilization techniques. The model—first unretrofitted, then retrofitted—was subjected to simulated earthquakes on a computer-controlled shaking table at IZIIS. Photo: Courtesy the Institute of Earthquake Engineering and Engineering Seismology.

The repaired and retrofitted model of the Church of St. Nikita, prior to the final test. Photo: Courtesy the Institute of Earthquake Engineering and Engineering Seismology.

The repaired and retrofitted model of the Church of St. Nikita, after the final test. As a result of the retrofitting, no structural damage to the model occurred. Photo: Courtesy the Institute of Earthquake Engineering and Engineering Seismology.