私有建物耐震補強期程與生命週期成本分析—以台北市為例

Abstract

由於建物環境的老化，許多城市面臨著越來越大的災害影響和風險。對現有建築物進行耐震補強是一種常見的減災策略。而在耐震補強的政策中，補強的目標與優先順序為此政策是否有效益的關鍵。本研究旨在從社會整體經濟的角度，進行生命週期成本和收益分析，為私有建物的補強政策提供參考。 首先，本論文回顧了不同國家的抗震補強策略，以確定合適的目標建築物與研究之設定。接著，將建築物特徵(如:樓高、樓地板面積、結構形式)配合容量譜法、易損性曲線和地震危害度分析評估，計算預期年地震損失，並通過歷史數據估算建築物建造成本和耐震補強成本，最後，採用等值年金法進行補強策略之生命週期成本與效益分析。 本研究以此架構嘗試分析臺灣臺北市私有建築物之不同耐震補強策略，策略以三個面向(優先級、工法、工程量能)分為總共18種策略，其中優先級由每棟建築的地震風險和補強成本決定，工法分為完全補強與階段性補強，工程量能則分為總補強面積、總補強目標棟數與總花費預算。針對一年到六年不同的政策期程進行了生命週期成本分析，得出每一策略的成本與效益，探討不同策略下所選定之目標建物與優先順序，以及不同工程量能對分析結果之影響。更分析了單一震源(山腳斷層)與多震源下的廣域型地震災害損失，加以進行比較討論。 由分析結果發現，根據目前工程量能之假設，以整體經濟效益的角度而言，一年期程的補強目標數量較適合臺北市目前的建物狀況，且提出了三種效益相對高的補強策略供決策者參考。接著以總工程預算作為工程量能進行模擬分析，獲得本研究建議的關鍵預算和最具經濟吸引力預算。最後，根據單一與多震源的地震危害度分析結果，未來研究應考量整體地震風險進一步探討多年期之耐震補強政策。

Owing to the aging of the built environment, many cities facing increasing disaster impacts and risk. Reinforcing the existing buildings is one common strategy for disaster risk mitigation. In the earthquake-resistant reinforcement policy, the priority of reinforcement and the budget are the keys to its effectiveness. This study aims to provide a reference for the reinforcement plan of private buildings through life cycle cost and benefit analysis from the perspective of overall economic benefits. First, seismic reinforcement projects in different countries are reviewed to determine appropriate target buildings and study settings. Next, the building characteristics (building height, floor area, structural form) are combined with Capacity Spectrum Method, fragility curve, and probabilistic seismic hazard analysis to calculate the estimated annual earthquake loss. Then, construction costs and seismic reinforcement costs are estimated through historical data. Finally, a life cycle cost analysis is conducted using the equivalent annuity method. The proposed analysis framework is used to analyze the seismic reinforcement plan of private buildings in Taipei City, Taiwan. It is categorized into a total of 18 strategies in three aspects (sorting criteria, construction method, and capacity constraint). Sorting criteria is determined by the seismic vulnerability and reinforcement cost of each building, and the construction method is divided into complete reinforcement and soft story reinforcement. The considered capacity constraints include the total reinforcement area, the total reinforcement target number and the total cost budget. The life cycle cost and benefit analysis results of each strategy in different policy duration are presented. The target buildings and priorities of different strategies are discussed, as well as the effect of different capacity constraints. Furthermore, the loss of earthquake disasters under a single source (Shanchiao fault) and multiple sources (overall seismic risk) are compared and discussed. The results show that the number of reinforcement targets in one-year duration is more feasible for the current analysis assumptions and building conditions in Taipei City from the perspective of overall economic benefits. Also, three cost-effective reinforcement strategies are provided as a reference for decision makers. Then, the critical budget and the most economically attractive budget in this study are obtained. Finally, single- and multi-source seismic risk analysis shows that overall seismic risk should be considered for future research.