結構物的底層結構破壞是常見的震損型態，台灣常見的中低樓層RC建築的底層空間基於空間以及經濟活動的需求設計使得強度或剛度相比於鄰層可能較弱，在過往的震損統計也指出損傷多集中於底層柱、牆體甚至不乏倒塌案例。增加底層結構剛性及強度的補強方式往往會限制空間的使用彈性而隔震工法需要較高的建造與維護成本難以實際應用在中低樓層民用住宅，因此本研究探討利用低成本的滑動式基礎於國內中低層結構中的耐震性能，以砂漿及鑄鐵等常見建築材料作為摩擦界面材料，並由鑄鐵承壓摩擦析出之石墨層達到較低且穩定的摩擦係數。研究以靜態實驗評估摩擦係數受各參數變化下的影響，並以實尺寸振動台實驗測試滑動式基礎之動態行為並與固定式基礎試體比較相應之結構物反應。
靜態摩擦試驗中，在FC250灰口鑄鐵與水泥砂漿的摩擦界面下，測得其穩定動摩擦係數在接觸正向面壓為2.6、4.4、5.2 MPa時分別為約0.30、0.33、0.36。並透過光學顯微觀察摩擦表面，確認了石墨析出並散佈於表面的混合潤滑狀態。確認選定摩擦界面之摩擦係數後，規劃以此界面作為滑動式基礎之實尺寸兩層樓鋼結構振動台實驗，以三向輸入JMA Kobe與TCU052兩筆地震波，測試安裝滑動式基礎後之整體動態行為，並與固定式基礎試體比較上部結構之耐震反應。
由實尺寸振動台實驗，獲得重點結論如下：
1. 在地震波的加載下大幅度的滑動發生次數並不多，因此在界面上相同位置多次反覆摩擦的狀況也不常發生，承壓摩擦當下其表面狀況應接近邊界潤滑狀態，經分析計算得到在較高速度滑動時其平均摩擦係數約為0.35~0.40。
2. 在JMA Kobe 50%的加載階段時，開始出現柱腳抬升的現象，在JMA Kobe 100%加載下擺動現象明顯加劇，柱腳抬升後強烈的碰撞會對基礎表面造成損傷，使基礎表面出現坑洞、砂漿碎塊，可能影響後續的摩擦行為。
3. 在實驗中發現即使有部分較大地震加載使試體出現擺動的行為，但是相對於固定式基礎試體，依然能夠有效的減低頂樓樓板水平加速度與一樓層間變形。
4. 在JMA Kobe 100%加載時對基礎的損傷之後，接續重新加載JMA Kobe 50%地震波以模擬強震後餘震，實驗中發現其與首次加載JMA Kobe 50%時的狀況大不相同，因為基礎坑洞或粉塵等表面損傷使基底剪力增加，整體行為相較於首次加載其搖擺的行為更加嚴重。

An experimental study was conducted to evaluate the seismic behavior of a structure equipped with a movable sliding base using cast iron and mortar at the interface. The preliminary friction test indicated that the graphite layer developed in the friction interface could effectively lubricate the surface after several cyclic slides and made the coefficient of friction between the interface to be 0.30 to 0.36 when applying corresponding normal compression stress 2.6 to 5.2 MPa. Normal compressive stress show little effect on the coefficient of friction. The shaking table tests on a free-standing frame was conducted by using the same material properties clarified in the preliminary test, which showed not only slide but also rock, rock-slide responses under large excitation. However, the sliding base showed a reduction of horizontal acceleration and story drift ratio comparing to the fixed specimen even collisions may fluctuate the resistance of base shear. Comparing the dynamic behavior of the same intensity inputs, the overall dynamic behavior and structural responses of the structure tended to be more severe under the shaking after the base was broken, which was caused by the collisions.

[1] C. P. Hsiao, Y. C. Ding, M. S. Sheu, and K. C. Tsai, “Investigation Report of the 921 Chi-Chi Earthquake: Structural Damages,” 1999.
[2] K. C. Tsai, C. P. Hsiao, and M. Bruneau, “Overview of Building Damages in 921 Chi-Chi Earthquake,” Earthquake Engineering and Engineering Seismology, vol. 2, no. 1. pp. 93–108, 2000.
[3] T. C. Chiou, L. H. Huang, P. W. Weng, Y. S. Ho, S. K. Wang, S. J. Hwang, L. L. Chung, and C. H. Yeh, “General Survey of the Buildings in Yujing District and the Damaged Building Data at the 2016 Meinong Earthquake in Taiwan (NCREE-18-003),” 2018.
[4] NCREE and P. University, “Building Data of the 20160206 Meinong Earthquake in Taiwan,” 2018. [Online]. Available: https://www.ncree.org/recce/20160206/.
[5] 藍百圻, “既有RC沿街店鋪住宅滿足功能要求之耐震補強,” 國立成功大學, 2002.
[6] 內政部營建署, 《建築物耐震設計規範及解說》. 內政部營建署, 2011.
[7] N. Mostaghel and M. Khodaverdian, “Dynamics of Resilient-Friction Base Isolator (R-FBI),” Earthq. Eng. Struct. Dyn., vol. 15, no. 3, pp. 379–390, 1987.
[8] V. A. Zayas, S. S. Low, and S. A. Mahin, “A Simple Pendulum Technique for Achieving Seismic Isolation,” Earthq. Spectra, vol. 6, no. 2, pp. 317–333, 1990.
[9] A. Mokha, M. C. Constantinou, A. M. Reinhorn, and V. A. Zayas, “Experimental Study of Friction-Pendulum Isolation System,” J. Struct. Eng., vol. 117, no. 4, pp. 1201–1217, 1991.
[10] P. Tsopelas, M. C. Constantinou, Y. S. Kim, and S. Okamoto, “Experimental Study of FPS System Bridge Seismic Isolation,” Earthq. Eng. Struct. Dyn., vol. 25, no. 1, pp. 65–78, 1996.
[11] A. Bakhshi, H. Araki, and T. Shimazu, “Evaluation of the Performance of a Suspension Isolation System Subjected to Strong Ground Motion,” Earthq. Eng. Struct. Dyn., vol. 27, no. 1, pp. 29–47, 1998.
[12] P. L. Y. Tiong, A. Adnan, A. B. A. Rahman, and A. K. Mirasa, “Seismic Base Isolation of Precast Wall System Using High Damping Rubber Bearing,” Earthquakes Struct., vol. 7, no. 6, pp. 1141–1169, 2014.
[13] G. G. Amiri, A. Shakouri, S. Veismoradi, and P. Namiranian, “Effect of Seismic Pounding on Buildings Isolated by Triple Friction Pendulum Bearing,” Earthquakes Struct., vol. 12, no. 1, pp. 35–45, 2017.
[14] A. S. Arya, “Sliding Concept for Mitigation of Earthquake Disaster to Masonry Buildings,” Proc. 8th World Conf. Earthq. Eng. San Fr. Calif., vol. 5, pp. 951–958, 1984.
[15] L. Li, “Base Isolation Measure for Aseismic Buildings in China,” Proc. 8th World Conf. Earthq. Eng. San Fr. Calif., vol. 6, pp. 791–798, 1984.
[16] T. Nagae, M. Ikenaga, M. Nakashima, and K. Suita, “Shear Friction Between Base Plate and Base Mortar in Exposed Steel Column Base,” J. Struct. Constr. Eng. AIJ, no. 606, pp. 217–223, 2006.
[17] J. McCormick, T. Nagae, M. Ikenaga, P. C. Zhang, M. Katsuo, and M. Nakashima, “Investigation of the Sliding Behavior Between Steel and Mortar for Seismic Applications in Structures,” Earthq. Eng. Struct. Dyn., vol. 38, pp. 1401–1419, 2009.
[18] R. Enokida, M. Ikenaga, T. Nagae, and M. Nakashima, “Kinematic Friction and Seismic Response of Free Standing Steel Structure on Mortar Base,” J. Struct. Constr. Eng. AIJ, vol. 76, no. 661, pp. 527–534, 2011.
[19] R. Enokida, T. Nagae, M. Ikenaga, M. Inami, and M. Nakashima, “Application of Graphite Lubrication for Column Base in Free Standing Steel Structure,” J. Struct. Constr. Eng. AIJ, vol. 78, no. 685, pp. 435–444, 2013.
[20] R. Enokida and T. Nagae, “Seismic Damage Reduction of a Structural System based on Nontraditional Sliding Interfaces with Graphite Lubrication,” J. Earthq. Eng., vol. 22, no. 4, pp. 666–686, 2017.
[21] K. Kajiwara, Y. Tosauchi, E. Sato, K. Fukuyama, T. Inoue, H. Shiohara, T. Kabeyasawa, T. Nagae, H. Fukuyama, T. Kabeyasawa, and T. Mukai, “2015 Three-dimensional Shaking Table Test of a 10-story Reinforced Concrete Building on the E-Defense; Part 1: Overview and Specimen Design of the Base Slip and Base Fixed Tests,” 16th World Conf. Earthq. Eng. Santiago, Chile, 9-13 January., no. 4012, 2017.
[22] E. Sato, Y. Tosauchi, K. Fukuyama, T. Inoue, K. Kajiwara, H. Shiohara, T. Kabeyasawa, T. Nagae, H. Fukuyama, T. Kabeyasawa, and T. Mukai, “2015 Three-dimensional Shaking Table Test of a 10-story Reinforced Concrete Building on the E-Defense; Part 2: Specimen Fabrication and Construction, Test Procedure, and Instrumentation Program,” 16th World Conf. Earthq. Eng. Santiago, Chile, 9-13 January., no. 4007, 2017.
[23] Y. Tosauchi, E. Sato, K. Fukuyama, T. Inoue, K. Kajiwara, H. Shiohara, T. Kabeyasawa, T. Nagae, H. Fukuyama, T. Kabeyasawa, and T. Mukai, “2015 Three-dimensional Shaking Table Test of a 10-story Reinforced Concrete Building on the E-Defense; Part 3: Base Slip and Base Fixed Test Results,” 16th World Conf. Earthq. Eng. Santiago, Chile, 9-13 January., no. 4016, 2017.
[24] F. Naeim and J. M. Kelly, Design of Seismic Isolated Structures: From Theory to Practice. New York: John Wiley & Sons, 1999.
[25] J. A. Calantarients, Improvements in and Connected with Building and Other Works, Construction and Appurtenances to Resist the Action of Earthquakes and the Like. 1909.
[26] A. S. Arya, B. Chandra, and M. Qamarruddin, “A New Building System for Improved Earthquake Performance,” Symp. Earthq. Eng., vol. 1, pp. 499–504, 1978.
[27] A. S. Arya, B. Chandra, and M. Qamarruddin, “New Concept for Resistance of Masonry Buildings in Severe Earthquake Shocks,” J. Inst. Eng. India, vol. 61, no. 6, pp. 302–308, 1981.
[28] B. G. Rabbat and H. G. Russell, “Friction Coefficient of Steel on Concrete or Grout,” J. Struct. Eng., vol. 111, no. 3, pp. 505–515, 1985.
[29] R. Stribeck, “Kugellager für beliebige Belastungen,” Zeitschrift des Vereins Dtsch. Ingenieure, vol. 45, 1901.
[30] Y. Ishiyama, “Motions of Rigid Bodies and Criteria for Overturning by Earthquake Excitations,” Earthq. Eng. Struct. Dyn., vol. 10, pp. 635–650, 1982.
[31] H. W. Shenton III, “Criteria for Initiation of Sliding, Rock, and Slide-Rock Rigid-Body Modes,” J. Eng. Mech., vol. 122, no. 7, pp. 690–693, 1996.
[32] F. Barbagallo, I. Hamashima, H. S. Hu, M. Kurata, and M. Nakashima, “Base shear capping buildings with graphite-lubricated bases for collapse prevention in extreme earthquakes,” Earthq. Eng. Struct. Dyn., vol. 46, pp. 1003–1021, 2017.