Experimental Study On Seismic Behavior Of Post-tensioned Prestressed Concrete Rocking Wall

The concrete shear wall can form a structural seismic system relatively economically and is easy to implement Anti-seismic measures.In the past devastating earthquakes at home and abroad,it played a vital role in safeguarding the safety of life and property.At present,the concrete shear wall commonly used in seismic fortification areas,especially in high-intensity areas,meets the requirements of the ultimate bearing capacity of the earthquake under normal earthquakes,and guarantees the rare earthquake under the earthquake.The anti-collapse requirements,the traditional design concept with structural ability as the main criterion essentially allows the structural members to enter nonlinearity to a certain extent,and causes the specific part of the structure to be damaged first in the earthquake to dissipate the seismic energy of the input structure..Although this design method can better control the collapse of the building,due to the excessive development of the plasticity of the section of the component,the building is often damaged,and the repair after the earthquake is difficult,and the indirect loss caused by the damage is serious.Therefore,more and more scholars have begun to pay attention to and develop new solutions to achieve rapid recovery of structural functions after the earthquake.The prestressing concrete rocking wall is a relatively new structural form,characterized in that the wall joint constraint is released,and the unbonded prestressing tendons are arranged along the wall.When a large earthquake occurs,a unique interface rocking mechanism is formed at the wall joint,and the structural seismic response is weakened by the tensioning effect of the rocking interface.It effectively promotes the rapid recovery of structural functions after the earthquake.In this paper,three post-tensioning unbonded prestressing rocking walls were designed and fabricated.The initial pre-stressing force and the number of prestressing tendons were used as the main parameters.The combination of test and simulation was used to study the pre-stressed rocking wall at low temperature.The hysteretic behavior under cyclic loading was analyzed.The hysteresis curve,skeleton curve,residual deformation,stiffness degradation,single-cycle energy consumption,cumulative energy consumption,etc.of the structure were analyzed.The initial prestressing and the prestressing tendons were compared and analyzed.The effect of quantity on the above indicators.The results show that the pre-stressed concrete rocking wall has small residual deformation,strong self-resetting ability and poor energy consumption.Increasing the initial prestressing can increase the elastic stiffness of the prestressing rocking wall,but there is almost no ultimate bearing capacity.Influence;increasing the number of prestressed tendons can significantly improve the stiffness and bearing capacity of the wall;the initial prestress and the number of prestressed tendons have no effect on the energy dissipation capacity of the prestressed rocking wall.The swaying collision characteristics of prestressed concrete rocking wall and foundation are studied by finite element numerical simulation.The results show that the initial prestressing stress mainly affects the vibration period of the prestressed rocking wall;the aspect ratio of the wall has a great influence on the rocking vibration characteristics,and the wall vibration attenuation speed of the small height and width is obviously accelerated.Finally,this paper proposes a method for calculating the energy consumption of wall and foundation collision by mapping method.