本文旨在探討加入餘震對機率式地震危害度分析的影響，比較不同案例及場址加入餘震前後PGA的年超越機率增加率。主要分為兩部份，第一部份為程式之驗證，參照PEER2018/03之案例，分別針對震源模式的差異、開裂面位置、面積、傾角、深度、地震規模和GMPE的不確定性，進行PSHA模擬及分析，並將本文的各場址PGA年超越機率與PEER2018/03提供的13套軟體分析結果進行比較；第二部份考慮加入餘震的場址PGA年超越機率，假設餘震均勻分佈於主震周邊，分別針對斷層震源、面震源、單次震源進行分析並比較餘震造成的超越機率增加率。本文結論為：(1) PEER2018/03所選擇的核心軟體並不一定能代表真實的地震PGA年超越機率，若以全部軟體進行判斷，結果會更為可信，本文使用的程式分析結果皆位於全部軟體的最大值與最小值之間，初步判定本文結果合理。(2) PEER2018/03的部份軟體在對稱的兩場址PGA年超越機率不一致，研判乃開裂面移動步數沒有修正為整數所導致。(3) 加入餘震後的各場址PGA年超越機率會上升，上升的比率與主震規模與場址位置有密切關聯，而又以場址和震源的相對位置影響最盛。(4) 餘震所致之超越機率增加率在高PGA時會提高，因此判斷需PSHA要考慮餘震的超越機率增加率影響較為完善。(5) 場址離斷層越遠，餘震的影響越大，反之亦然，乃因餘震分佈廣，且為均勻分佈之故。(6) 面震源餘震危害度貢獻最高的場址坐落於圓心，乃因離中央場址較遠的主震，其餘震回到場址附近的機會高於其他場址。(7) 主震為單次震源的情況下，場址離主震越近，餘震危害度貢獻比例越低，反之亦然。

The purpose of this paper is to investigate the impact of the addition of aftershocks on the probability seismic hazard analysis, and to compare the increase of PGA annual rate in different cases exclude and include the aftershocks. It is mainly divided into two parts. The first part is the verification of the program according to the case of PEER2018/03. The second part considers the PGA annual excess probability of include aftershocks. Assume that the aftershocks are uniformly distributed around mainshock. Fault source, surface source, and single source were analyzed and compared. The conclusions of this paper are as follows: (1) The core software selected by PEER2018/03 does not absolutely represent the actual PGA annual probability of excess. If judged by all software, the result will be more credible. The program results of this paper are all located between the maximum and minimum values of all software, then interfering that the results is reasonable. (2) Some software results of PEER2018/03 are not same in the symmetric two sites. The judgment is that the number of moving steps of the cracking surface is not corrected to an integer. (3) The PGA annual probability of excess of each site will increase after the addition of aftershocks. The rate of increase is closely related to the magnitude of the mainshock and the location of the site, and is most affected by the relative position of the site and the source. (4) The rate of increase caused by aftershocks will increase at high PGA. Therefore, it is necessary to judge the need for PSHA to consider the effect of aftershocks. (5) The farther the site is from the fault, the greater the impact of the aftershocks is. The aftershocks are widely distributed and evenly distributed. (6) The site with the highest contribution to the aftershock damage of the surface source is located in the center of the circle, which is due to the main shock far from the central site. The chances of the other earthquakes returning to the vicinity of the site are higher than those of other sites. (7) When the mainshock is a single source, the closer the site is to the mainshock, the lower the contribution of the aftershock make, and vice versa.

Abrahamson, N. A. & Silva, W. J. (1997), Empirical Response Spectral Attenuation Relations for Shallow Crustal Earthquakes, Seismological Research Letter, Vol. 68, pp.105-106.
Bommer, J. J. (2002), Deterministic VS. Probabilitic Seismic Hazard Assessment: an Exaggerated and Obstructive Dichotomy, Journal of Earthquake Engineering, Vol. 6, pp. 43-73.
Chang, C.-H., Wu, Y.-M., Zhao, L., & Wu, F. T. (2007). Aftershocks of the 1999 Chi-Chi, Taiwan, Earthquake: The First Hour, Bulletin of the Seismological Society of America, Vol. 97(4), pp. 1245–1258.
Chang, Y.-W., Loh, C.-H. & Jean, W.-Y.(2017) Time-Predictable Model Application in Probabilistic Seismic Hazard Analysis of Faults in Taiwan, Terrestrial Atmospheric and Oceanic Sciences, Vol. 28(6), pp. 815-831
Cornell, C. A. (1968), Engineering Seismic Risk Analysis, Bulletin of the Seismological Society of America. Vol. 58(5), pp. 1583-1606
Der Kiureghian, A & Ang, A. H-S. (1977), A Fault-Rupture Model for Seismic Risk Analysis, Bulletin of the Seismological Society of America, Vol. 67(4), pp. 1173-1194.
Gutenberg, B. & Richter, C. F. (1956), Magnitude and Energy of Earthquakes, Annali di Geofisica, Vol. 9(1)
Hale, C., Abrahamson, N. & Bozorgnia, Y. (2018), Probabilistic Seismic Hazard Analysis Code Verification, Pacific Earthquake Engineering Research Center, PEER Report 2018/03, University of California, Berkeley
Hong, L.-L. & Guo, S.-W. (1995), Nonstationary Poisson Model for Earthquake Occurrences, Bulletin of the Seismological Society of America, Vol. 85(3), pp. 814-824.
Pu, H.-C. (2018), Spatial and Temporal Characteristics of the Microseismicity Preceding the 2016 ML 6.6 Meinong Earthquake in Southern Taiwan. Pure and Applied Geophysics, Vol. 175(6),pp.2077–2091
Sadigh, K., Chang, C.-Y., Egan, J. A., Makdisi, F., & Youngs, R. R. (1997). Attenuation Relationships for Shallow Crustal Earthquakes Based on California Strong Motion Data. Seismological Research Letters, Vol. 68(1), pp.180–189.
Thomas, P., Wong, I. & Abrahamson, N. (2010), Verification of Probabilistic Seismic Hazard Analysis Computer Programs, PEER Report 2010/106 , University of California, Berkeley
Toda, S., Stein, R. S., Reasenberg, P. A., Dieterich, J. H., & Yoshida, A. (1998), Stress Transferred by the 1995 Mw=6.9 Kobe, Japan, Shock: Effect on Aftershocks and Future Earthquake Probabilities. Journal of Geophysical Research: Solid Earth, Vol. 103(B10), pp. 24543–24565.
Wang, J. H. (1989), The Taiwan Telemetered Seismographic Network. Physics of the Earth and Planetary Interiors, Vol. 58(1), pp.9–18
Wu, Y.-M. (2006), Seismic Quiescence before the 1999 Chi-Chi, Taiwan, Mw 7.6 Earthquake. Bulletin of the Seismological Society of America, Vol. 96(1), pp. 321–327.
Wu, Y.-M. & L.-Y. Chiao (2006), Seismic Quiescence before the 1999 Chi-Chi, Taiwan, Mw 7.6 Earthquake. Bulletin of the Seismological Society of America, Vol. 96(1), pp. 321–327.
Youngs, R. R. & Coppersmith, K. J. (1985), Implications of Fault Slip Rates and Earthquake Recurrence Models to Probabilistic Seismic Hazard Estimates, Bulletin of the Seismological Society of America, Vol. 75(4), pp. 939-964.
鄭世楠、葉永田(1989)，「西元1604年至1988年台灣地區地震目錄」，中國地質學會年會。
葉永田、鄭世楠、辛在勤、何美儀 (1995)，「臺灣地區數個地震目錄的地震定位與規模之評估(三)」，中央氣象局地震技術報告彙編，第 11 卷。
鄭世楠、王子賓、林祖慰、江嘉豪 (2010)，「台灣地區地震目錄的建置(I)(II)」，中央氣象局地震技術報告彙編，第 54、57 卷。