Experimental Research On Seismic Behavior Of Full-scale Precast Shear Wall Substructure

Precast concrete shear wall structure was researched and designed by Harbin Institute of Technology for industrialized building system of prefabricated structure, whose characteristic is that major structural parts are prefabricated in the factory and qualified parts are transported to the construction site for large-scale lifting construction, subsequently forming overall structure. This structural system has advantages of high construction speed, high product quality, energy-saving and environmental protection, which is appropriate for the development of housing industry of China.The core technology of precast concrete shear wall structure system is the connection between the parts. By the way of grouting reinforcement plug-lap connection, nine shear wall specimens were made based on the construction method of criterion, and then the compressive perform test study of them was carried out on long-column test machine. Of which two specimens were tested by axial compression and through the load - strain curve, mechanical properties of elasticity was analyzed. In addition, according to the varying strain of steel and concrete located at the lap, the work state of steel and concrete was analyzed. Seven specimens were tested by eccentric compression and the influence of bearing capacity given by bar diameter was compared. Moreover, the ultimate failure mode of specimens meets the minimum eccentric damage theory. Within the steel lap the concrete section should meet the plane section assumption. The limit bearing capacity of specimen is same with that of cast-in-situ structure through calculating; besides specimen have no shortage of anchor damage.Based on the conclusion of massive basic connection perform tests, three-layer full scale shear wall structure was designed and its single degree of freedom pseudo static test and multiple degree of freedom pseudo dynamic test was carried out to investigate the influence of seismic performance of overall structure given by using grouting on the plug-in connection and level connection. 63t actuator was used in quasi-static test to apply back and forth level force gradually on the three top levels until a visible level crack on the bottom of the structure happened. hysteresis loop of sub-structure and strain of lap steel bar in dark pillars area were obtained by arranging in each layer by high-precision displacement gauge. Test analysis shows that structure does not crack under fortification earthquake force, the whole structure keep in the elastic state and the drift angle of each layer meets the specification limits. During the experiment, the overall structural stiffness degradation is relatively slow, no apparent stiffness mutating. According to the distribution of dark pillars of strain, shear wall of loading direction was wall with limbs.A little modification on the structure should be made when carrying out multi-degree of freedom pseudo-dynamic test. That is, the original loading position keeps unchanged in static loading and loading positions were added on the top of first and second layers to simulate the earthquake. The selected El-Centro earthquake ground motion wave is 12s and the peak accelerations are 35gal, 70gal, 110gal amd 220gal respectively. The sub-structure developed from the elastic state to elastic-plastic state and plastic state. Beams crack and form cross-cracks, eventually destroy, producing significant plastic hinge. The bend-shear slanting crack appeared at the first layer wall and structural damage mode was mainly bending. Data of pseudo-dynamic test show that the prefabricated concrete shear wall failure modes and energy dissipation mechanism are exactly some with that of cast-in-situ structure. In addition, the overall structure has large ductility and energy dissipation characteristics. The design of all parts'connections was safe and reliable, in the testing process anchor damage did not happen and structural measures met the needs of the force. Sub-structure pseudo-dynamic test results show that precast concrete shear walls meets the fortified targets of "minor earthquake no impairment, middle earthquake repair deserving, big earthquake not down", which can be applied in the earthquake zone.After the end of sub-structure seismic test, the basic components of the capacity test was conducted, including the composite slab, prefabricated balconies, precast stairs. Sand was used to simulate uniform load on composite floors and precast balcony, obtaining deflection curve of structure. Precast stair consists of precast beams and prefabricated ladder bench plate, loading by using two jacks, and getting deflection curves under each stage of loading. The results show that when computing capacity limit is reached, the structure of connections between the parts of measures ensure reliable connections and anchor damage does not occur, thus can be analyzed on cast theoretical analysis.Precast concrete wall sub-structure model experiment proves that parts of the connection are reliable in the overall structure and feasible in the practical application. Precast concrete shear wall system as a new type of structural system, will greatly promote the development of housing industry in China.