Shake Table Tests of a Two-Story Woodframe House

As discussed previously, shake table tests were performed on a simplified fullscale two-story single-family house under Task 1.1.1 of the CUREe-Caltech Woodframe Project. The main objective of this testing was to quantify the dynamic response of the structure with various structural configurations. Since there has been a lack of understanding of the behavior of full-scale structural woodframe systems, these shake table tests attempt to improve this understanding. In addition, this project generated extensive experimental data at the system level.

The test structure is 16 ft by 20 ft in footprint and is anchored to the UC San Diego uniaxial shake table such that shaking occurs along the short dimension of the structure (North-South direction). The structural components of the test structure are full-scale, however the plans dimensions of the test structure are smaller than a typical residence due to restrictions of the shake table. The lateral load resisting system consists of exterior shearwalls sheathed with Oriented Strand Board (OSB). The structure was tested during 10 different phases of construction with varying diaphragm properties and shearwall configurations. For each of the first four phases of testing, quasi-static tests on the structure were performed to determine the in-plane stiffness of the floor diaphragm. For the last six phases of testing, quasi-static tests, frequency evaluation tests, damping evaluation tests, and seismic tests were performed on the test structure. The test structure was repaired between each phase of testing to return the lateral load resisting system to its initial strength and stiffness. The test structure was instrumented with nearly 300 displacement, acceleration, and force measuring devices to maximize the amount of information regarding the response of the structure during the various tests.