A comparative evaluation of the FEMA 154 rapid visual screening, Canadian seismic screening, and Japanese seismic index methods and their applications

Major earthquakes may have a destructive effect on buildings that have not received structural design services (i.e. nonengineered buildings). While new buildings are designed in accordance with the guidelines proposed in seismic and structural regulations and are safe against expected lateral loads, buildings that were erected without seismic considerations may frequently sustain serious damage or suffer from collapses. For this reason, it is crucial to evaluate and determine the seismic safety level of existing buildings to save human lives and to mitigate property loss. Detailed structural analyses have to be performed in order to ascertain the practical risk level that the existing building stock generates under future earthquakes. On the other hand, when the vast amount of building stock is taken into consideration, however, it becomes evident that detailed structural analyses pose serious financial and temporal problems. Methods of rapid seismic performance assessments (or rapid seismic screening methods) have been developed as a solution to this problem. With these methods, the aim is to analyze buildings rapidly and easily, rank them according to risk levels, and determine the buildings considered that should have the top priority for more detailed evaluations. This study selects and examines three methods of rapid seismic performance assessment, which are widely used in many countries. FEMA 154 Rapid Visual Screening was developed by the Applied Technology Council (ATC) in the USA and was updated in 2015. The Canadian Seismic Evaluation Method was developed by the National Research Council Canada (NRCC). The Japanese Seismic Index Method was developed by the Japan Building Disaster Prevention Association (JBDPA) and was updated in 2001. This study initially explains in detail FEMA 154 Rapid Visual Screening, Canadian Seismic Evaluation Method, and the first phase of Japanese Seismic Index Method. All three methods are then applied on a selected elementary school building that consists of three different blocks. These blocks were built in different years using different structural load carrying systems. At the end of the study, a comparison of the conclusions reached by the investigation of these three methods is presented. Comparative advantages and disadvantages of the selected methods and the possible applicability on the existing building stock in Turkey are emphasized. It is concluded that the FEMA 154 Rapid Visual Screening Method and the Canadian Seismic Screening Method are the most rapid assessment methods and can be applied for all types of buildings. On the other hand, the Japanese Seismic Index Method requires much longer time for evaluations but would provide more reliable results. As a result of extensive investigations made in this work, with the use of local data, it is concluded that The Canadian Seismic Evaluation Method can be implemented rapidly in a reliable way in the rapid seismic secreening of buildings in Turkey. The thesis consists of eleven chapters: In the First Chapter which consists of Introduction, importance of the subject and scope are given. Literature review related to seismic screening methods is studied in the Second Chapter. The principals, definitions, and parameters of the FEMA 154 Rapid Visual Screening are comprehesively explained in the Third Chapter. For better understanding, the method is summarized by a flow chart. An overview of this method is given in the Fourth Chapter. In the Fifth Chapter, thorough information on structural system types, irregularities, and principles is provided for the Canadian Seismic Screening Method. A general evaluation of this method is also presented in the Sixth Chapter. The Japanese Seismic Index Method is examined in the Seventh Chapter, and similarly an overview for this method is presented in the Eighth Chapter. A general evaluation of all seismic screening methods is discussed in the Ninth Chapter. The selected methods are then applied on a selected extremely complex building in the Tenth Chapter. The last chapter, the Eleventh Chapter, is devoted to the conclusions and suggestions drawn from this comparative work. In the FEMA 154 Rapid Visual Screening Method, it is assumed that the buildings are constructed with details and materials that are in compliance with the building design code of the relevant construction year. For this reason, the construction year of the building, the code year, and the benchmark year should be determined correctly when using this method. Otherwise, the results may be misleading. The code year and the benchmark year especially have an impact on the resulting score. For this reason, this method is not appropriate for use in Turkey, due to the fact that the majority of the existing buildings are not constructed in compliance with the regulations. In the event that this method is applied in Turkey, it is recommended that the building be evaluated as pre-code and pre-benchmark, regardless of the construction year. The application of the FEMA 154 Rapid Visual Screening Method is indeed convenient and easy; 10 to 15 minutes are enough for the evaluation of a given building. In addition, the building can be evaluated only by observation from the outside. It is not required to examine the structural system or the architectural projects of the building in order to be able to analyze it. Apart from these, a preliminary survey is necessary in order to determine seismicity, ground conditions, and geological hazards. This method is appropriate for all building types. Even when the final score shows that the building is safe, particular conditions that would require a detailed analysis are listed on the data collection sheet, such as pounding effect elements from the adjacent building that carry the risk of falling, F ground type, and geological hazards. This precaution increases the safety of this method. The Canadian Seismic Evaluation Method (guideline) yields swift results and is easy to apply. The building may be evaluated only by observation from the outside. A preliminary survey is required for determining the seismicity of the region and information regarding ground conditions. The parameters and possible scenarios that are listed in the guidelines and the data collection sheet are explained in detail in this study. This method can be applied on all building types, which is its most important quality, and its application is quite swift. The difference of the current Canadian Seismic Evaluation Method from the FEMA 154 Rapid Visual Screening Method and the guideline version of the Canadian Seismic Evaluation Method lies in the fact that the results are independent from the code year and the benchmark year. Apart from that, type of slab and the general condition of the building are included in the evaluation. Since it does not depend on the code and benchmark years, its use in Turkey would yield much safer results when compared with other available methods. The Japanese Seismic Index Method is a more detailed/rigorous method than others, relying on various approximate structural calculations. In this method, the seismic performance of each floor of the building is calculated in line with the two orthogonal directions. For the seismic performance to be calculated, the dimensions of the elements of the vertical load bearing system, the compressive strength of the material that was used, and the weight of each floor need to be known. Depending on the type of analysis carried out on the building, each block requires a detailed analysis. This method was developed for buildings that have few to medium number of stories; it is not possible to use it on other types of structures. This constitutes the most negative aspect of the method. In addition, this method requires a much longer time period for the examination of the buildings than the other methods. However, it can be said that it yields safer results, since it takes the material type and the dimensions of the load bearing system into consideration while assessing the seismic performance of the building.