本研究以峴港砂為試驗材料，探討在不同水泥配比與養治時間之條件下改良土及未改良土之力學性質，以瞭解水泥對砂土靜態及動態力學性質之改良效果。本研究之實驗重點乃以相對密度為40%之砂土，配以0.3%、0.5%及0.7%的水泥配比製作改良土試體，經7天、14天及28天養治後，進行無圍壓縮試驗、單向度壓密試驗、靜力三軸試驗及動力三軸試驗。
由試驗結果可知，水泥配比愈高，改良土的無圍壓縮強度愈高。改良土的無圍壓縮強度與養治時間之對數約呈線性增加之趨勢，且隨著水泥配比的增加，其△qu /△log tc的斜率愈大。當壓密壓力低於改良預壓力時，改良土水泥配比愈高，其壓縮指數有減少的趨勢，此一現象表示添加水泥的確可使土壤的壓密沉陷減少。
土壤添加水泥後，水泥的膠結作用使得顆粒間獲得大量的凝聚力，但這同時，顆粒間的摩擦力並未隨之等量提高，令抵抗破壞的剪力強度傾向於較大部份由凝聚力承受，亦即凝聚力將因水泥配比提高而大幅增加，摩擦角卻相對地減小。
本研究中，配比為0.5%之改良土試體的液化阻抗在養治時間28天比養治時間7天約增加37%，養治時間14天比養治時間7天約增加16%，而改良土試體養治時間為7、14及28天之液化阻抗約為未改良土試體之1.6~2.4倍。另外，本研究亦探討了改良土之剪力模數、阻尼比與配比間的關係，經試驗後，發現改良土對以上諸特性均有良好之改良效果。

This research focused on mechanical properties of cement treated and untreated sands, and discussed the effects of cement improvement. Cement treated sand specimens with relative density of 40﹪and cement mixing rates of 0.3%, 0.5% and 0.7% were used in the tests. Through various curing periods including 7, 14 and 28 days, unconfined compression tests, consolidation tests, triaxial compression tests and dynamic triaxial tests were performed.
From the experimental results, it is observed that the unconfined compression strengths of treated sands increased with the increase of cement mixing rates. The unconfined compression strengths of treated sands are also increased linearly proportional to the logarithm of curing periods. The compression indexes of treated sands decreased with the increase of cement mixing rates under the consolidation pressures lower than the treated preconsolidation pressure. These results show that the consolidation settlements can be reduced through the increase of cement mixing rates.
The cohesion of treated sands increased with the increase of cement mixing rates, but the friction angle of sand did not increase as much as that of cohesion under the same condition. These results make the cohesion of treated sands to bear most shear stress until failure.
The liquefaction resistance in 28 days is 37% higher than that of 7 days; the liquefaction resistance in 14 days is 16% higher than that of 7 days. On the whole, the liquefaction resistance of treated sands is 1.6~2.4 times higher than that of untreated sands when the curing periods are classified into three procedures including 7, 14, and 28 days. In addition, the relationships of shear modulus, damping ratio and cement mixing rates were investigated.

1.土質工學會，土質試驗法，日本土質工學會，第172~188頁，(1979)。
2.吳偉特，「臺灣地區砂性土壤液化潛能之初步分析」，土木水利季刊，第六卷，第二期，第.39~70頁，（1979）。
3.宋勻文，「台北盆地北投地區基隆河黏土之動態性質」，碩士論文，國立中央大學土木工程學系，中壢（1998）。
4.林耀煌，「地盤改良工法」，地工技術雜誌，第八期，第16~25頁，（1984）。
5.金永斌、游啟亨、蕭達鴻，「砂土添加水泥熟料液化穩定研究」，中國土木水利工程學會七十二年年會暨慶祝十週年紀念研討會論文，第651~671頁，台北(1983)。
6.張惠文、曾迪華、李顯智、鄭清江、徐瑞祥，「台灣地區海岸填海造地技術整合第一期計畫」，行政院公共工程委員會專案研究計畫成果報告，計畫編號：86-技-03，(1997)。
7.張惠文、廖新興、鄭清江，「砂質地盤液化之防治方法探討」，地工技術雜誌，第三十八期，第17-29頁，(1987)。
8.張惠文，「中央大學地盤改良課程講義」，課程講義，國立中央大學土木工程學系，中壢（1999）。
9.張惠文，「利用水泥及石灰系材料之深層攪拌工法」，現代營建，第三十八期，第45~50頁，（1984）。
10.張惠文、陳修，「水泥系改良土之工程特性」，行政院國家科學委員會研究計畫，計畫編號：NSC74-0410-E008-04，(1985)。
11.張善同，「旋轉灌漿固化地基之技術」，中國鐵道出版社，北京（1984）。
12.陳志安，「不同程度影響因素對不同緊密度砂土液化特性之研究」，碩士論文，國立台灣大學土木工程研究所，台北（1990）。
13.陳修，「水泥系改良土之工程特性」，碩士論文，國立中央大學土木工程學系，中壢(1985)。
14.黃麗兒，「水泥混合處理砂質土壤液化特性之改良研究」，碩士論文，國立中央大學土木工程學系，中壢(2001)。
15.黃安斌、張嘉偉、何應璋、葉嘉鎮，「雲林麥寮粉土細砂之工程性質」，地工技術，第六十七期，第55-68頁，(1998)。
16.蔡宗宏，「台灣西部近岸抽砂回填土壤液化潛能之研究」，碩士論文，國立海洋大學河海工程研究所，基隆(1993)。
17.蔡政泰，「添加波索蘭材料之水泥系改良土工程性質之研究」，碩士論文，國立成功大學土木工程研究所，台南(1995)。
18.Chung, K.Y.C. and Wong, I.H., “Liquefaction Potenial of Soils with Plastic Fines,” Soil Dynamics and Earthquake Engineering Conference, Southampton, July, pp.887-897(1982).
19.Dupas, I.M. and Decker, A., “Static and Dynamic Properties of Sand Cement,” Journal of Geotechnical Engineering Division, ASCE, Vol. 105, No.GT3, June, pp.799-817(1981).
20.Erten, D. and Maher, M.H., “Cyclic Undrained Behavior of Siltysand,” Soil Dynamic and Earthquake Engineering, pp.115-123(1995).
21.Hardin, B.O. and Richart, F.E., “Elastic Wave Velocities in Granular Soils,” Journal of Soils Mechanics and Foundations Division, ASCE, Vol.89, No.SM1, pp.33-65(1963).
22.Hardin, B.O. and Black, W.L., “Sand Stiffness Under Various Triaxial Stresses,” Journal of Soils Mechanics and Foundations Division, ASCE, Vol.92, No.SM2, pp.27-42(1966).
23.Hardin, B.O. and Drnevich, V.P., “Shear Modulus and Damping in Soil：Measurement and Parameter Effects,” Journal of Soils Mechanics and Foundations Division, ASCE, Vol.98, No.SM6, pp.603-624(1972).
24.Ishihara, K. and Tadatsu, H., “Stability of Natural Deposit during Earthquake,” 教育部暨交通大學土研所主辦，土壤液化潛能評估與地滑之穩定分析，研習會講義(1979).
25.Ishihara, K., “Liquefaction and Flow Failure during Earthquakes,” Geotechnique, Vol. 43, No. 3, pp. 351-415(1993).
26.K’ezdi, A., “Stabilized Earth Roads,” Developments in Geotechnical Engineering 19, New York,(1979).
27.Kawasaki, T., et. al., “Deep Mixing Method Using Cement Hardening Agent,” Proceedings of 10th ICSMFE., Stokeholm, pp.509-565(1981).
28.Lee, K.L. and Fitton, J.A., “Factors Affecting the Cyclic Loading Strength of Soil,” Vibration Effects of Earthquakes on Soils and Foundations, ASTM STP 450, pp.801-821(1969).
29.Peacock, W.H. and Seed, H.B., “Sand Liquefaction under Cyclic Loading Simple Shear Conditions,” Journal of he Soil Mechanics and Foundations Division, ASCE, Vol.9, No. SM3, pp.689-708(1968).
30.Saxena, S.K. et al., “Liquefaction Resistance of Artificially Cemented Sand,” Journal of Geotechnical Engineering Division, ASCE, Vol. 114, No.12, pp.1395-1413(1988).
31.Seed, H.B., “Evaluation of Soil Liquefaction Effects on Level Ground during Earthquakes,” Liquefaction Problems in Geotechnical Engineering Session on Soil Dynamics Committee of Geotechnical Engineering Division, ASCE, pp.1-104(1976).
32.Seed, H.B. and Lee, K.L., “Liquefaction of Saturated Sands during Cyclic Loading,” Journal of the Soil Mechanics and Foundation Division, ASCE, Vol. 92, No. SM6, pp. 105-134(1966).
33.Seed, H.B., Wong, R.T., Idriss, I.M., and Toimatsu, K., “Moduli and Damping Factors for Dynamic Analysis of Cohesionless Soils,” Journal of Geotechnical Engineering Division, ASCE, Vol.112, No.GT11, pp.1016-1032(1986).
34.Tringale, P.T., “Soil Identification In-situ Using an Acoustic Cone Penetrometer,” Ph.D. Dissertation, University of California, Berkeley (1983).
35.Umehara, Y., Zen, K., and Yoshizawa,H., 1990, “Design Concept of Treated Ground by Premixing Method,“ Geo-coast, 3-6, Sep., Yokohama, pp.519-524(1991).
36.Vaid, Y.P. and Chern, J.C., “Cyclic and Monotonic Undrained Response of Saturated Sands,” National Convension Session on Advance in the Art of Testing Soils Under Cyclic Loading, ASCE, Detroit, pp.120-147(1985).
37.Wai, F.C. and Atef, F.S., “Constitutive Equations for Engineering Materials,” Elsevier Science, pp.122-123(1983).
38.Zen, K., “Development of Premixing Method as a Measure to Construct a Liquefaction-free Reclaimed Land,” Tsuchi-to-kiso, JSSMFE, Vol. 36, No.6, pp.27-32(1990).