Earthquake Loss Risk Assessment And Collaple Resistant Roubustness Design Method For RC Frame Structures

Recently, earthquakes frequently occur all over the world. Almost everyearthquake has brought a painful lesson to humans. The great Wenchuan earthquakeindicates that, even the buildings structures designed according to the currentseismic design code would have possibilities of collapse when encounteredunpredicted rare or even very rare earthquakes. Therefore, it is of theoretical andrealistic significance to develop seismic risk assessment and robustness analysis ofcode-conforming structures. In this thesis, from the viewpoint of earthquake losses,the seismic risk of reinforced concerete frame structures is evaluated, and therisk-based collapse resistant robustness design method is explored. The maincontents are as follows:Firstly, on the basis of earthquake loss estimation, risk metrics in financeengineering and catastrophe insurance such as Occurrence Exceeding Probability(OEP), Aggregate Exceeding Probability (AEP), Excess Expected Loss (XSEAL),Return Period Loss (RPL) and Tail Conditional Expection (TCE), etc., areintroduced to assess the direct economic loss, indirect economic loss and humancasualties loss of reinforced concerete frame structures under earthquakes indetailed.Secondly, the above three kinds of earthquake losses are disaggregated intotheir contributions from the following factors: loss at various levels of groundmotion intensity, non-collapse and collapse losses, non-collapse loss estimated atdifferent stories, non-collapse loss estimated at different component categories, andnon-collapse loss estimated at different damage states.Thirdly, by using multi-way analysis of variance (MANOVA) and tornadodiagrams techniques, the sensitivity of expected loss of the building at differentlevels of ground motion intensity when collapse has not occurred, is analyzed.Through the direct differentiation method, the sensitivity of expected loss of thebuilding at different levels of ground motion intensity is also analyzed.Lastly, using JCSS’s decision-making framework, the robustness of structuresis quantitatively assessed by the comparison of the direct risk with the total risk.Through the parameter analysis of structural robustness, the trend of the robustnessis obtained. By using the life cycle theory of strctures, according to the principle ofthe minimum life cycle cost, the optimal fortication intensity of different sites anddifferent stories are found, and the the robustness indices of different sites anddifferent stories of RC frame structures are recommended.