Seismic Testing of Two-Story Woodframe House: Influence of Wall Finish Materials

A two-story, single-family woodframe house, designed according to current engineered code seismic design requirements, was tested on a uniaxial shake table. The main objectives of this experimental study were to determine the dynamic characteristics and the seismic performance of the test structure under various base input intensities representative of both ordinary and near-field ground motions in southern California. The structure was tested with and without interior (gypsum wall board) and exterior (stucco) wall finish materials. The test results revealed good performance of the engineered woodframe structure. Wall finish materials are usually considered in design as nonstructural elements. However, the structure incorporating wall finish materials exhibited a substantial increase in its lateral stiffness and a dramatic reduction in its seismic displacement response. Furthermore, the seismic acceleration response of the structure was only moderately increased by the presence of wall finish materials. These shake table test results provide the motivation for further studies on the evaluation of the long-term effectiveness of wall finish materials as potential structural components of lateral load-resisting systems of woodframe structures.