A simplified analysis procedure to determine the nonlinear seismic demands of numerous high-rise buildings with RC shear walls | |
| Author | Phichaya Suwansaya |
| Call Number | AIT Diss no.ST-23-01 |
| Subject(s) | Tall buildings--Design and construction Tall buildings--Earthquake effects Earthquake resistant design |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering in Structural Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. ST-23-01 |
| Abstract | Over the last few decades, there has been a significant increase in the construction of high-rise buildings around the world. The safety and serviceability of these buildings against earthquake is one of biggest concerns of the building residents, the city official, and other stakeholders. It is, however, not easy to evaluate the seismic safety and serviceability of such structures due to several reasons. Firstly, each building is made from a large number of various structural and non-structural components with different properties and different response characteristics. Secondly, its dynamic responses to seismic ground shaking are also quite complicated, where several vibration modes other the fundamental mode often contribute significantly to the responses. Thirdly, the responses to strong ground shakings, which determine the seismic safety of the building, are likely to exceed the elastic limits of the structure, causing damage of various forms to different components of the building. Therefore, the analysis procedure chosen for assessing the seismic performance of the building needs to properly account for all these factors. In practice, the seismic performance of high-rise buildings is commonly evaluated by using the Non-Linear Response History Analysis (NLRHA) procedure. This procedure, however, may require a substantial amount of computing effort, time, expertise, and other resources. Therefore, it may be suitable for some applications, especially when the accuracy and reliability of evaluation results are crucial and the number of buildings to be evaluated is one or a few. For example, this procedure can be used for checking the design of a high-rise building in the final design stage to ensure that all seismic responses of interest are within acceptable limits. It can also be used for guiding the seismic retrofit design of an existing high-rise building. For some other applications, however, such procedure may not be suitable. For example, the estimation of seismic losses of a city for a given earthquake scenario will require the seismic performance evaluation of a large number of high-rise buildings. It is practically impossible to apply the NLRHA-based procedure to all buildings. In this study, a simplified analysis procedure for evaluating the nonlinear seismic responses of high-rise buildings with RC shear walls is proposed. It is developed from the use of the Uncoupled Modal Response History Analysis (UMRHA) procedure and the Coupled Shear-Flexural Cantilever Beam Model (CSFCBM). The UMRHA procedure allows us to compute the nonlinear seismic responses mode-by-mode, where each vibration mode is assumed to behave like a nonlinear Single-Degree-of-Freedom (SDOF) system. The nonlinear seismic responses are approximately represented by the sum of modal responses of a few vibration modes. The UMRHA procedure has been applied in many recent studies to estimate nonlinear seismic responses of many high rise buildings with different heights, configurations and arrangement of shear walls, and its accuracy was found to be satisfactory. By this way, the degree of freedom can be reduced from several thousands (NLRHA) to just a few (UMRHA), and the computational effort and time are greatly reduced. However, the UMRHA procedure requires the knowledge of modal properties and modal hysteretic behavior. These modal parameters can be typically obtained from an eigen analysis and a cyclic modal pushover analysis of a full 3D nonlinear finite element model (FEM), respectively. This is also a time and effort consuming work. Hence, the CSFCBM is introduced here to approximately represent the high-rise building. This is one of the simplest models that can simulate the complex behavior of a wall-frame structural system. This model is used for estimating the required modal properties and modal hysteretic parameters without performing such procedures. Using four case study high-rise buildings with reinforced concrete shear walls (30-, 34- , 19- and 45-story height), the accuracy of the proposed simplified procedure is examined. In this examination, the seismic demands computed by the NLRHA procedure, which are used as benchmarks, are compared with those computed by the proposed simplified procedure. It is observed that the proposed simplified analysis procedure is providing reasonably accurate demand estimations for four case study buildings subjected to different input ground motions. This satisfactory performance shows that it can be considered (and developed further for general use) as a suitable analysis option in cases where it is not practical to perform the detailed NLRHA procedure. Several developments can be made in future to make this procedure applicable to buildings and structures of various types, configurations, and materials used as well as enhance the accuracy of this proposed procedure. The proposed simplified analysis procedure has many possible applications. It could be used for estimating seismic damage and losses of many high-rise buildings in a city for a given earthquake scenario. Risk-based premium for earthquake insurance of high rise buildings could also be determined by using the evaluation results from this procedure. One may use the procedure for quick assessment of various seismic design options of a high-rise building in the preliminary design phase, where many structural details have not yet been specified and accurate estimate of seismic responses may not be required. |
| Year | 2023 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. ST-23-01 |
| Type | Dissertation |
| School | School of Engineering and Technology |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pennung Warnitchai,; |
| Examination Committee(s) | Anwar, Naveed;Punchet Thammarak;Chao, Kuo Chieh; |
| Scholarship Donor(s) | Royal Thai Government;AIT Fellowship; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2023 |