Energy Dissipation Frame System Research Based On Rocking Wall Mechanism

Different from common energy-dissipating systems,the rocking wall can't dissipate any energy or change the natural vibration period of a structure,all the while,it controls the deformation mode of a frame structure in an ideal pattern relying upon the stiffness and strength of itself.Meanwhile,it can also be combined with energy dissipaters to effectively reduce the deformation of the controlled structure.As an auxiliary substructure to the main frame,the rocking system can be fabricated and installed by the modern industrial technique.To fulfill its purpose,the rocking wall needs a large stiffness and bearing capacity,and it remains elastic even being caught by a rarely occurred earthquake.It is really a challenge for a component made of reinforced concrete.To this end,this study proposed an assembled rocking wall using double steel skin infilled concrete wall(DSSICW).The component adopts double steel layers as the mold infilled by concrete,so that both advantages of steel and concrete can be fully achieved.The two pieces of components in adjacent stories are connected by bolts.The component can be fabricated in a factory and shipped to the construction site.After assembling the components,the rocking wall is connected to the main RC frame by metallic dampers.The dampers not only dissipate energy during an earthquake,they also transfer the story shear force between the main RC frame and the rocking wall.In order to investigate its performance in controlling the deformation mode,a series of experiments were conducted.In this study,three specimens were fabricated and tested,including two rocking wall frame specimens and one RC frame specimen for comparison.The quasi-static test indicates that DSSICW remained monolithic during the entire process of test.It effectively confines the deformation mode and increased the energy dissipation capacity by over 70%.However,because of the lack of additional gravity,the rocking wall was hoist during test by the dampers along the sides of the wall.The aseismic performance was affected as well although not so significantly.It is concluded that additional pre-stressed gravity is needed to limit the vertical deformation.Based on the test results,the rocking wall system was designed for a real application to passively control the seismic deformation.The rocking systems were adopted in the longitudinal direction,while the traditional wall-type dampers were used in the lateral direction.Another advantage of the rocking system is that the required architectural space is very limited.The dampers can be arranged in a single bay along both sides of the rocking wall.It shall be noted that the attached columns shall be carefully reexamined.The size and rebars shall be enlarged if needed.The analytical results show that this new type of rocking system is an effective and practical technique to reduce the seismic demand,satisfying the aseismic requirement for structures in a seismic-prone area.