Two-stage Simplified Calculation Model And Random Earthquake Response Analysis Of Multi-ribbed Composite Wall Structure

As a new structural system with a bright development prospect, multi-ribbed composite wall structure (MRCWS) has the advantages of ecological materials, lightweight, fast construction, energy conservation and seismic performance. Today, in multi-storied and moderate-high storied structure, both the theoretical research and the engineering application of MRCWS all gained stage achievements. However, being a new assembled monolithic structural system, its complex force-bearing characteristics and unique construction details result in great difficulties in its simplified calculation model. Based on previous studies, this dissertation, through experimental studies and numerical analysis, is devoted to two-stage simplified calculation model of the structure and focuses on nonlinear static procedure, aseismic capability assessment and random earthquake response analysis of MRCWS. The main research work and results are as follows:1.Under guidance of damage-reduction seismic design, MRCWS is defined as dual seismic structural system. With its force-bearing characteristics and construction details, the MRCWS is decomposed into damage-reduction component and main body structure. And that means damage-reduction component is the multi-ribbed composite slab that is regarded as the first defending line of the structure; while concealed frame (including end frame columns, connecting columns, concealed beams and cast-in-place floor) is the main body structure, which is regarded as the second defending line of the structure.2. Based on previous experimental results, the failure process and stress characteristics of the specimen including composite slab without filled blocks, single multi-ribbed composite slab, multi-ribbed composite coupled slab, single multi-ribbed composite wall, and the multi-ribbed composite coupled wall are comparatively analyzed. In macroscopic perspective, the collaborative work mechanism and internal factors of several aseismic defending lines of multi-ribbed composite wall are discussed, the results of which provide important basis for the modeling of the structure. And the two-stage seismic design method for MRCWS is established.3. On the basis of experimental studies, a mechanical model called rigid frames-elastic composite panel model which can be used to solve the design and calculation problems of MRCWS is put forward to calculate the internal force and deformation of MRCWS during the elastic stage. By using this model, previous experiments of multi-ribbed composite walls and a 1/10-scaled model shaking table test of 10 stories multi-ribbed slab structure are simulated. The result shows that the model has high calculation accuracy and the simulation can reflect the load-bearing characteristic of the structure. Meanwhile, with the application of the rigid frames-elastic composite panel model, the elastic deformation checking and the time history analysis of a completed MRCWS are presented.4. According to the previous experiments and analyses, the multi-ribbed composite slab is equivalent to a whole diagonal brace. Then, the rigid frame-equivalent brace model of multi-ribbed slab structure is put forward to calculate the elastic-plastic calculation and analysis of MRCWS, which can be used to solve the problems of elastic-plastic deformation calculation, elastic-plastic time history analysis and aseismic capability assessment of the structure. The main parameters such as the width and the plastic hinge settings of the diagonal brace are established on the previous tests'results. By using this model, a shaking table model of MRCWS is simulated. The calculating results tally well with the experimental results in acceleration and displacement time history and the max displacement of monitoring points. The results indicate that the rigid frame-equivalent brace model can better reflect the dynamic characteristics and elastic-plastic deformation situation of the prototype structure. Thus this model can be applied to elastic-plastic time-history analysis and nonlinear deformation checking of MRCWS.5. Target displacement method and capacity spectrum method that are accepted by FEMA-273 and ATC-40 are introduced. On the pushover analysis of multi-ribbed composite walls of previous experiments, the adaptability of later load patterns to the walls is discussed. At the same time, the capacity spectrum method is used to aseismic capability assessment of MRCWS and according to China code, the process is presented by giving an example analysis. And a simplified method of aseismic capability assessment is established, in which the design response spectrum of China can be applied.6. The translational components and rotational components of multiple seismic ground motions model and its relativity are summarized and discussed. The multiple random earthquake response analysis of MRCWS is presented by using Clough-Penzien spectrum as translational components and rotational power spectrum proposed by Li Hongnan etc. And the reaction characteristics of MRCWS with multiple seismic ground motions input and that with single seismic ground motions input are comparative analyzed.The originalities of this dissertation lie in:1. Under guidance of damage-reduction seismic design, the two-stage seismic design method for MRCWS is established.MRCWS is decomposed to the damage-reduction component and the main body structure. Different models are suggested to be adopted in different load-bearing stages which can be used into the two-stage seismic design method of MRCWS. And the working procedure of the two-stage seismic design method is put forward.2. The rigid frames-elastic composite panel model and the rigid frame-equivalent brace model of MRCWS are established.Based on pervious experimental studies, the rigid frames-elastic composite panel model is established to solve the problems of the structure in elastic stage, such as internal force calculating, deformation checking and the designing in first stage. And the rigid frame-equivalent brace model is put forward to solve the problems in plastic stage, such as nonlinear internal force, deformation calculating and the design of the structure in second stage.3. A simplified ATC-40 capacity spectrum method is suggested in the aseismic capability assessment of MRCWS through the usage of the rigid frame-equivalent brace model.The ATC-40 capacity spectrum method is introduced into the aseismic capability assessment of MRCWS. And based on this method, a simplified ATC-40 capacity spectrum method in the aseismic capability assessment of MRCWS is suggested, in which the design response spectrum of China is applied as demand spectrum andα-Teff spectrum is applied as the capacity spectrum of the structure.4. The reaction characteristics of MRCWS with multiple seismic ground motions input and that with single seismic ground motions input are comparatively analyzed.By using Clough-Penzien spectrum as translational component and rotational power spectrum proposed by Li Hongnan etc. as rotational component of ground motions input, the random earthquake response analysis of MRCWS is presented. And the reaction characteristics of symmetric and asymmetric MRCWS with multiple seismic ground motions input and that with single seismic ground motions input are comparatively analyzed.