|CUREE-Caltech Woodframe Project
Element 1 - Testing & Analysis
Task 1.1.1: Shake Table Tests of a Simplified Two-Story Single-Family House
PI: André Filiatrault ; Co-PIs: Chia-Ming Uang and Frieder Seible (UC San Diego)
There is a lack of understanding of the seismic behavior of woodframe structural systems. Few numerical models capable of analyzing the seismic behavior of three-dimensional woodframe structures currently exist. Also, only limited experimental data have been generated at the system level. There is a need for more test data on the seismic response of complete full-scale woodframe structures to improve the understanding of the state-of-the-art and the state-of-practice of analysis and design. Considering the low weight-to-strength ratio of wood and the availability of high performance shake tables in California, shake table testing is the most attractive and realistic procedure for system testing.
The main objective of Task 1.1.1 is to perform shake table testing on a simplified full-scale two-story single-family house to measure and quantify the buildings overall dynamic responses for various construction configurations and to document how the distribution of forces within the structure may change between the various configurations.
The test structure for Task 1.1.1 represents a simplified full-scale two-story single family house, with design details that are typical of current California residential construction practice. The footprint of the structure is 16 ft x 20 ft and is anchored to the shake table such that shaking will occur along the short dimension of the structure (north-south direction). The construction is at full scale, however the plan dimensions of the structure are smaller than would be of a typical residence due to the restrictions of the shake table. The lateral load resisting system of the test structure parallel to the shaking direction (east and west elevations) consists of exterior shear walls along with two interior partition walls on the second floor. All wood structural panels are sheathed with 3/8"-OSB and are fastened to the framing with 8d gun nails.
To maximize the experimental data that can be extracted from the test structure, 10 different test phases have been conducted at various stages of construction. The first four phases involve quasi-static testing of the first story only in order to evaluate the in-plane stiffness of the floor diaphragm under various nailing and block configurations. The last six test phases involve seismic tests of the complete structure for various construction configurations. The test structure has been repaired between test stages to return the lateral load resisting system to its initial strength and stiffness.