永久變形試驗的結果顯示路基土壤材料在重覆載重作用下，累積永久變形量隨著載重次數的增加而逐漸增加。受測試體若達明顯穩定狀態，則試體受到反覆循環的軸差應力作用不會出現破壞的現象。高含水量、高應力水準下欲達試體的明顯穩定狀態，需要較多的重覆載重次數。達到明顯穩定狀態下的路基土壤受測試體，其回彈應變量與累積永久變形量，經由量化的統計迴歸方式分析後發現彼此間存在著明顯的相關性；此明顯的相關性將有助於設計研究人員以較少的施測次數（100次）試驗，來預測受測試體達明顯穩定狀態時所累積的永久變形。
此預測的模式將可大幅節省為求受測試體達明顯穩定狀態時所需的施測時間。預測的模式還可用於估計回彈模數值，以作為路基土壤鋪面厚度設計時參考之用。

Results of the permanent strain test shows that the accumulated permanent strain of subgrade soil under repeated loading continues to build up with increasing load repetitions. If the tested soil approaches apparent shakedown state, the tested soil does not appear failures after the deviator stress of repeated load cycles. Approaching apparent shakedown state of the tested soils under high water content and high stress level needs more repeated load repetitions. The relationship of the resilient modulus and permanent strain of tested subgrade soil, at apparent shakedown state, is established using statistic regression. The relationship helps designers in predicting accumulated permanent strain as the tested soils reach apparent shakedown state with less testing times.
This prediction model will enormously save the testing time needed as reaching the expected apparent shakedown state of tested soils. This prediction model also can evaluate the values of resilient modulus as the reference of designing the thickness of pavements of subgrade soil.

1.李謙偉，「路基土壤回彈模數測定及儀器製作」，住宅及都市發展局月刊，第135期，第45∼56頁（1996）。
2.林志棟，「公路土壤力學原理（結構篇）」，科技圖書股份有限公司，臺北（1987）。
3.蘇百加，「夯實紅土材料回彈模數之研究」，碩士論文，國立臺灣科技大學營建工程研究所，臺北（1988）。
4.林志棟、黃偉慶，「台灣地區柔性路面厚度手冊研擬」，國立中央大學土木工程研究所（1996）。
5.陳進，「路基土壤回彈模數（Mr）特性之研究」，碩士論文，國立中央大學土木工程研究所，中壢（1987）。
6.Muhanna, A.S., "A Testing Procedure and a Model for Resilient Modulus and Accumulated Plastic Strain of Cohesive Subgrade Soils." Ph.D. dissertation. North Carolina State University, Raleigh (1994).
7.Muhanna, A.S., Rahman, M.S., and Lambe, P.C., "Model for resilient modulus and permanent strain of subgrade soils." Transportation Research Record 1619, pp. 85-93 (1998).
8.Huang, Y.H., Pavement Analysis and Design, Prentic-Hall, New Jersey, U.S.A. (1993).
9.American Association of State Highway and Transportation Officials, Guide for Design of Pavement Structures (Volume 1), AASHTO(1986,1993,1998).
10.Raad, L., Weichert, D., and Ali, H., "Shakedown and fatigue of pavements with granular bases." Transportation Research Record 1227, pp. 159-172 (1989).
11.Raad, L., Weichert, D., and Ali, H., "Analysis of full-depth asphalt concrete pavements using shakedown theory." Transportation Research Record 1227, pp. 53-65 (1989).
12.張惠煌，「林口紅土微觀土粒結構之研究」，碩士論文，國立臺灣大學土木工程研究所，臺北（1985）。
13.王慶麟，「林口台地紅土邊坡坡壞模式之研究」，碩士論文，國立臺灣大學土木工程研究所，（1984）。
14.吳崇正，「初始含水量對林口紅土夯實性質影響之研究」，碩士論文，國立臺灣科技大學營建工程研究所，臺北（1987）。
15.彭根隆，「紅土飽和膨脹與壓縮特性之研究」，碩士論文，國立中央大學土木工程研究所，中壢（1985）。
16.何憲禎，「以動力三軸試驗決定粘性土壤之動態性質」，碩士論文，國立中央大學土木工程研究所，中壢（1984）。
17.房性中，「路基土壤彈性模數值與CBR值柔性路面厚度設計方法之研究」，碩士論文，私立中原大學土木及水利工程研究所，中壢（1987）。
18.歐章煜，「台灣北區紅土之強度與滲透性研究」，碩士論文，國立成功大學土木工程研究所，臺南（1979）。
19.林炳森，「舖面設計之初步研究」，大地工程學術研究會論文專輯，臺北，第359~374頁（1985）。
20.Sharp, R. W., "Pavement design based on shakedown analysis." Transportation Research Record 1022, pp. 99-107 (1985).
21.Uzan, J., "Characterization of granular material." Transportation Research Record 1022, pp. 52-59 (1985).
22.Edil, T. B., and Motan, S. E., "Soil-water potential and resilient behavior of subgrade soils." Transportation Research Record 705, pp. 54-63 (1979).
23.Monismith, C. L., Ogawan, N., and Freeme, C. R., "Pavement deformation characteristics of subgrade soils due to repeated loading." Transportation Research Record 537, pp. 1-17 (1975).
24.Das, B. M., Advanced Soil Mechanics, third edition, PWS Publishing Company, U.S.A. (1993).
25.Raad, L., Weichert, D., Boulbibane, M., and Collins, I. F., "Shakedown analysis of anisotropic asphalt concrete pavements with clay subgrade." Canadian Geotechnical Journal, Vol. 37, No. 4, pp. 882-889 (2000).
26.Raad, L., Weichert, D., and Boulbibane, M., "Determination and application of resilient modulus - numerical application of shakedown theory to pavements with anisotropic layer properties." Transportation Research Record 1687, pp. 75-84 (1999).
27.Das, B.M., Principles of Geotechnical Engineering, third edition, PWS Publishing Company, U.S.A. (1993).