SEISMIC STABILIZATION OF HISTORIC ADOBE STRUCTURES
WILLIAM S. GINELL, & E. LEROY TOLLES
11 11. CONCLUSIONS
The results of the studies performed as part of the Getty Seismic Adobe Project have shown that effective seismic retrofit measures can be implemented with only minor effects on historic building fabric. Information is now available to go beyond the pre-existing conflict between the conservation community's desire to preserve these buildings and the rightful concerns for life safety. The retrofit measures developed and tested in this research project can effectively provide for life safety by minimizing the possibility of catastrophic collapse while having a minimal impact on the historic building fabric. In the latter case, straps can be recessed into chases in the wall and covered with adobe rendering. Where wall painting or decorative elements exist on wall surfaces and the grooving of walls to accommodate straps would not be permitted, center cores may be used without major intervention damage.
This research effort has provided the necessary technical information to justify the use of several minimally intrusive retrofit measures. The major accomplishments of the project were:
- development of the basic theoretical framework for understanding the concept of stability rather than strength-based systems for adobe buildings;
- development of retrofit systems that were shown to be very effective in providing life safety by preventing collapse and in minimizing the extent of damage;
- testing of a set of retrofit techniques that can be used on historic adobe buildings;
- documentation of the study of the seismic performance of historic adobe buildings after the Northridge earthquake.
The results of the survey and their correlation with experimental data are significant and provide a large amount of information that can be useful in understanding the performance of historic adobe buildings and in developing further techniques for retrofitting this type of building.
The GSAP program has been successful in using a multidisciplinary approach throughout the research effort, and the concern for protecting historic fabric, as well as life safety, was a constant theme that guided the design and implementation of the studies.