| China is a Nation with frequently-occurred earthquake disasters.The earthquake-resistance and disaster-prevention of buildings,structures and infrastructures concern the safety of people’s livelihood and properties,and in the meantime,are key subjects for civil engineering to continuously solve new challenges achieve innovative development.The prefabrication of building structures is the inevitable course for industrialization of construction industry,information construction as well as intelligentization in our country.The prefabricated reinforced concrete(RC)structures have been widely constructed,and the innovation of structural system and improvement of seismic performance are the key scientific issues.RC shear walls act as the primary lateral-load-resisting system for high-rise buildings,and unfortunately,the prefabrication,connection techniques and seismic performance have always been the bottleneck restricting the development of prefabricated high-rise buildings.On the basis of systematically investigating and analyzing the seismic performance and vibration reduction of pin-supported wall and corresponding wall-frame system,a prefabricated "dryconnected" RC shear wall characterized by multi-story rocking and energy dissipation was proposed,and a category of integrated-prefabrication structural systems using steel board(serving as energy dissipation element or device)and shear walls were developed.In this way,an efficient path for the development of prefabricated high-rise building structures is being explored with the purpose of improving precast/prefabrication efficiency,as well as the seismic performance and vibration control of structures.The seismic performance and vibration control of prefabricated rocking shear wall and corresponding building structures are investigated in this dissertation.Firstly,researches were conducted on the pin-supported wall-frame system by establishing the continuous parameter mechanical model for elastic seismic response calculation,proposing the energy-balance-based approach for inelastic seismic design,developing a practical method to calculate damper parameters controlled by roof design target displacement,revealing the failure mode and evaluating the collapse prevention capacity of the system by using dynamic inelastic time history analysis.Then,a prefabricated dry-connection RC shear wall characterized by multistory rocking and energy dissipation was proposed.The nonlinear hysteretic and energy dissipation capacity of the proposed shear wall was experimentally investigated and the numerical analytical model was established.Analysis results revealed that the proposed shear wall has better energy dissipation capacity over other prefabricated shear walls as well as castin-place shear wall.Finally,a category of structures was developed using the proposed prefabricated shear wall as the primary lateral-load-resisting system,such as the wall-frame structure.Research was conducted by proposing corresponding seismic resistance and vibration reduction calculation method,as well as the seismic design approach.and a design example was provided.The monolithic pin-supported rocking wall was expanded to prefabricated RC shear wall characterized by multi-story rocking and energy dissipation in this dissertation.The prefabricated RC shear wall incorporating dry-connection multi-story rocking and energydissipative steel board element(device),as well as a category of structures using the novel shear wall as the primary lateral-load-resisting system were proposed.The inelastic calculating models for the shear wall and corresponding structure were established,and seismic analysis and design approach were investigated.The primary content and innovative research findings were introduced as follows:(1)The continuous model for the elastic seismic response analysis of pin-supported wall-frame structure was established,the energy-balance-based approach for inelastic seismic design of the system was developed,and a design approach incorporating seismic force distribution,damper parameter calculation and strength design of structural members was proposed.According to the collaborative functioning mechanism of frame,pinsupported wall and dampers in the system,an continuous assumption was made to establish the governing differential equation describing the lateral displacement of pin-supported wall under equivalent seismic reversed-triangular lateral force profile.By solving the equation,the elastic displacement response and distributions of shear force and moment for the frame and pinsupported wall could be acquired,revealing the influence of damper stiffness on the shear force and moment distribution in the frame and wall.According to the distribution features of interstory drift ratio,the distribution of seismic forces between frame and wall was deducted.By setting the design target displacement and appropriate failure mode,the seismic energy-balance equation for energy-dissipative pin-supported wall-frame system was introduced to determine the design lateral forces,and the strength design of structural members could be finished by distributing the lateral forces between frame and wall.The continuous model for pin-supported wall-frame system deals with the solution of elastic displacement response,calculation of member internal forces and distribution of seismic lateral forces.It can be applied as an effective tool to give rapid seismic response prediction for pin-supported wall-frame system at initial design stage.(2)For the pin-supported wall-frame system,a practical approach to calculate damper parameters controlled by roof design target displacement was proposed,revealing the characteristics of seismic inelastic response and damage evolution law.Transforming the roof-displacement-base-shear curve of pin-supported wall-frame structure into the capacity curve of an equivalent SDOF system,the equivalent period for the structure reaching roof design target displacement can be determined using the equivalent linearization method.Then,the equivalent viscous damping ratio demand at design target displacement can be determined by combining the equivalent period and demand spectra,and thus damper parameters can be calculated and designed.Analysis results of the example structure revealed that the proposed approach had high accuracy especially for the design of damper parameters in pin-supported wall-frame system dominated by fundamental vibration mode.With simple procedures,the approach is appropriated to be applied in practical engineering.Furthermore,three performance stages of structural members(devices)were defined including yielding of dampers,initial yielding of longitudinal reinforcement(formation of plastic hinge)and crushing of concrete.With the use of dynamic time history analysis method,the damage evolution law of the structure under inelastic seismic response was analyzed.The sequence for structural members(devices)reaching the previously defined performance stages as well as the distribution and degree of plastic hinges were followed and marked from both time and space perspective,and thus the failure path and failure mode can be identified.Analysis results indicated that on account of the restraining effect of pin-supported wall on frame lateral deformation,the pin-supported wallframe system is prone to achieve a“strong-column-weak-beam" global failure mode characterized by occurrence of plastic hinges only at beam ends and uniform inter-story drift.(3)The“dry-connected”prefabricated RC shear wall incorporating multi-story rocking and energy-dissipative steel board element(device)was proposed.There full size shear wall model were designed and fabricated based on which quasi-static test was conducted,revealing the satisfying hysteretic energy dissipation capacity of the proposed shear wall.To meet the need of developing prefabricated high-rise buildings,a prefabricated"dry-connected" RC shear wall characterized by multi-story rocking and energy dissipation was proposed.Adopting vertical prestress compression and high-strength bolt fastening techniques,RC precast wall element and energy dissipation devices(energy-dissipative steel board)are incorporated and assembled to form the prefabricated "dry-connected" energy-dissipative shear wall lateral-load-resisting system which can rock at multi-story tooth-space-like connections under ground motions.An approach was proposed to calculate and design the flexural bearing capacity at the connection.Three full size shear wall models were designed and fabricated for reversed cyclic loading test.The seismic performance and vibration reduction of the multi-story rocking shear wall were revealed by analyzing its damage distribution characteristics,hysteretic energy dissipation capacity and failure pattern,etc.Analysis results indicated that the shear wall exhibited the lateral deformation profile to rock about the multi-story connections under reversed cyclic loads.Sparse crack distribution and low damage were observed during the test.The hysteresis curve had a bow-like shape,indicating adequate lateral load resistance and energy dissipation capacity.The monolithic pin-supported rocking wall was expanded to multistory energy-dissipative rocking shear wall,providing an effective way to develop novel shear wall lateral load resisting system for prefabricated high-rise buildings.(4)The refined finite element model and simplified smeared-connection analytical model for the prefabricated "dry-connected”RC shear wall characterized by multi-story rocking and energy dissipation were proposed.The seismic performance of the proposed shear wall in this research and those of several other prefabricated shear walls were compared and evaluated,indicating a better lateral load resistance and energy dissipation capacity in the proposed shear wall in this research.Firstly,the refined numerical model of the prefabricated multi-story rocking energy-dissipative shear wall was established using solid elements.The model reasonably reflected local mechanical properties of the shear wall including vertical prestress compression,bolt force fastening,connection contact and force transfer between embedded steel boards.By comparing numerical modeling result to the experiment result,it was concluded that the refined FEM model could describe the global hysteretic behavior of the shear wall,reasonably reflecting the process of damage development as well as explaining the failure mode of the shear wall.The simplified smeared-connection analytical model for the prefabricated multi-story rocking energy-dissipative shear wall was developed with the use of fiber elements and spring elements.This model ignores local tension effects in concrete and reinforcement,and transforms the concentrated deformation at the connection into an equivalent smeared deformation in the tension region of the wall panel.The simplified model provides relatively reasonable prediction of the nonlinear behavior of the wall specimen during the test,while enjoys a greatly-improved calculation efficiency compared with the refined model.Based on the simplified model,comparative analysis were conducted to evaluate the seismic performances of shear walls with different construction details including the wall proposed in the research,grouted-sleeve-connected prefabricated shear wall,groutedsleeve-connected prestressed rocking shear wall and cast-in-place shear wall.Analysis results indicated that the shear wall proposed in this research had better energy dissipation capacity compered with other prefabricated or cast-in-place shear walls,while the lateral load resistance was slightly smaller than the cast-in-place shear wall.(5)A category of high-rise building structures using the proposed prefabricated "dryconnected”RC shear wall characterized by multi-story rocking and energy dissipation were developed.The three-dimensional numerical model for inelastic seismic analysis was established.Approaches were proposed including structural seismic analysis and design,and a design example was also provided.The calculation and design approach based on design target displacement of the prefabricated multi-story rocking energy-dissipative RC shear wall structure was developed.By setting the design target displacement and displacement ductility coefficient of the structure,the inelastic displacement spectra of the equivalent SDOF systems with different displacement ductility coefficient were established,and the equivalent periods and seismic design forces could be determined.Then,distribute the seismic design forces to each wall panel,calculate the strength demand at the connection and conduct the design of connection section.A 12-story example structure was designed using the proposed method,and the corresponding three-dimensional numerical model for inelastic seismic analysis was established.Results of the dynamic inelastic time history analysis revealed that the example structure could satisfy the target displacement demand.Under seismic loading,the lateral displacement of the example structure increased with the increase of story number,indicating a multi-story rocking lateral displacement profile.Calculation results also proved the satisfying lateral load resistance and hysteretic energy dissipation capacity for the proposed prefabricated high-rise buildings. |
