標準貫入試驗(Standard Penetration Test, SPT)為目前環太平洋地區最普遍使用之現地土壤試驗法，由於落錘打擊數 值對應土壤強度的關係易為工程師理解，加上施作簡易，自1902年推出至今已累積龐大試驗資料，以及眾多以N值評估土壤性質的相關公式。發展初期缺乏試驗設備相關規定，造成各地區設備差異，因此在1960年代，N值受設備影響的現象開始被提出後，針對SPT各部分對N值影響的研究陸續發表，卻常出現結論不一致的情形。1977年提出以力量平方法(F2M)為基礎之能量檢測法，以及發現N值與打擊能量比ERr呈反比關係後，方確定SPT定量研究方法。1986年 能量檢測法成為規範修正 值的建議方法，同年波動方程分析(wave equation analysis, WEA)發展成熟，搭配力量-速度法(FVM)用於打樁動力分析，在1997年證實FVM較F2M不受鑽桿內接頭影響之前，1995年已有眾多現地試驗指出F2M能量修正 值仍具極大變異，因而撤銷相關規範，且至今尚無新規範提出。本文承續SPT研究歷程，針對過去研究結論未定或忽略之處，探討SPT試驗系統，包含落錘型式是否影響試驗結果、鉆板對於打擊能量影響程度，以及能量計算法（F2M 與FVM）未考慮鑽桿內接頭數變化的影響。研究方法包含實驗室控制試驗、F2M能量檢測法、適用於SPT之波動方程分析，以及現地資料匯整。落錘研究方面，針對三式圓柱形落錘，以及一式安全式落錘，進行操作方式相同之實驗室試驗，以及波動方程分析結果，發現落錘型式對於ERr影響在5%內，對於N值修正影響不大。鉆板研究方面，針對台灣地區之平頂型鉆板，以及根據圓弧面應力集中概念設計之圓頂型鉆板，進行實驗室試驗與匯整現地資料，發現圓頂型鉆板有助於提高ERr與提升打擊穩定性。在鑽桿-接頭研究方面，藉由波動方程分析計算40組現場可能之鑽桿組合，探討F2M與FVM打擊能量受接頭影響程度，並提出接頭修正概念以及係數kJ，當kJ=1時即不受接頭影響，結果發現F2M之kJ在0.81至0.91間，FVM之kJ在0.96至1.01間，顯示F2M能量受接頭影響較大。結論指出，在落錘與鉆板方面，落錘型式對於打擊能量影響不大，但長形且底面積較小之落錘，以及圓頂型鉆板皆有助於打擊能量與打擊穩定性提升；在鑽桿接頭方面，能量計算法F2M與FVM經kJ修正後，可在相同基準比較，並提高N值修正可信度。本研究結果有助於SPT試驗品質改進與試驗結果可信度提昇。

　Standard Penetration Test (SPT), an in-situ soil testing method for foundation engineering, is commonly seen in practices around the Pacific Ocean area. The basic concept of the method is based on the inversely proportional relationship between the number of hammer blow, i.e. the SPT-N value, and the hardness of soil, i.e. the soil strength. Due to the simplicity in both theory and application, SPT has become very popular since its first available in 1902 and resulted in a large database and numerous N-value equations for soil properties determination. In the meantime, however, the conceptual simplicity makes the method difficult to standardize the operation equipments. Not until 1960’s when a report first suspected the influence of the testing equipments on the N value, some studies started to talk about this important issue. The present study is to quantitatively analyze the effects of some mechanical factors, including the hammer factor, the anvil factor and rod-connector factor, on the SPT energy measurement. Two energy measurement methods, the force square method (F2M) proposed in 1977 and the force-velocity method (FVM) proposed in 1997 are employed. One analytical method, wave equation analysis (WEA), was developed for the numerical analysis.

　In the laboratory controlled testing, three cylinder hammers and one safety hammer were adopted to study the hammer factor. The test results show that the influence of the different hammers on the measured ERr is limited within 5%.
In the study of anvil factor, a round-top anvil was found to be more effectively than conventional flat-top anvil on transferring the pounding energy from the hammer to the rod. The result-in ERr’s show that the round-top anvil can provide not only more amount but better stable energy transferring between the hammer and the rod.

In the study of rod-connector factor, WEA method was chosen to analyze forty cases of different rod-connector assembly regarding the influence of the connectors on the results of F2M and FVM. The analytical results summarize a correction factor kJ for correlating the measurements of the two methods. With kJ=1 as the benchmark the kJ corrections for F2M and FVM are between 0.81 to 0.91 and 0.96 to 1.01, respectively. This shows that the connector has larger influence to the F2M method.

[1]Abou-matar, H. and G. G. Goble, “SPT Dynamic Analysis and Measurements,”ASCE Journal of Geotechnical and Geoenvironmental Engineering, Vol.123, No.10, pp.921~928, 1997.
[2]Adam, J., Discussion, Session 1, Proceedings, Fourth Pan American Conference on Soil Mechanics and Foundation Engineering, Vol. 3, pp.8284, 1971.
[3]ASTM D 1586-98, Standard Test Method for Penetration Test and Split-Barrel Sampling on Soils, American Society of Testing and Material, Annual Book of ASTM Standards, Vol.04.08, American Society of Testing and Material, Philadelphia, USA.
[4]ASTM D 4633-86, Standard Test Method for Stress Wave Energy Measurement for Dynamic Penetrometer Testing Systems, Annual Book of ASTM Standards, Vol.04.08, American Society of Testing and Material, Philadelphia, USA.
[5]ASTM D 6066-98, Standard Practice for Determining the Normalized Penetration Resistance of Sands for Evaluation of Liquefaction Potential (D 6066-98), Annual Book of ASTM Standards, Vol.04.09, American Society of Testing and Material, Philadelphia.
[6]ASTM website, http://www.astm.org, 2005.
[7]Brown, R. E., “Drill Rod Inference on Standard Penetration Test,” Journal of the Geotechnical Engineering, Vol. 103, No. GT11, pp. 1332-1336, 1977.
[8]Clayton, C. R. I., “SPT Energy Transmission: Theory, Measurement and Significance,” Ground Engineering, ASCE, 1990.
[9]Decker, M. D., “The Energy Transfer Characteristics of SPT Hammer,” Master Project Report, Dept. of Civil Engineering, Purdue University, 1983.
[10]DeGodoy, N. S., “The Standard Penetration Test,” Proceedings, Fourth Pan American Conference on Soil Mechanics and Foundation Engineering, Vol. 3, pp.100-103, 1971.
[11]Drumlight, E. E. and Pfingsten, C. W., “Influence of Hammer Type on SPT Results,” Journal of Geotechnical Engineering, Vol. 122, No. 7, pp. 598-599, 1996.
[12]Engel, P. A., “Impact Wear of Materials,” Elsevier Science Publishing Inc., New York, 1978.
[13]ESCPT (1977) “Report of the Subcommittee on Standardization of Penetration Testing in Europe,” Proceedings of the Ninth International Conference on Soil Mechanics and Foundation Engineering, Vol. III, IX ICSMFE, Tokyo, Japan, pp. 95-120.
[14]Fairhurst, C., “Wave Mechanics of Percussive Drilling,” Mine and Quarry Engineering, Part 1, Vol. 3, pp.122-130, and Part 2, Vol.4, pp.169-178, 1961.
[15]Fletcher, G. F. A., “Standard Penetration Test: Its Uses and Abuses,” Journal of the Soil Mechanics and Foundation Division, Proceedings of the American Society of Civil Engineers, Vol.91, No.SM4, pp.67-75, 1965.
[16]Graff, K. F., “Wave Motion in Elastic Solids,” Dover Publication Inc., New York, 1991.
[17]Gibbs, H .J., and Holtz, W. G., “Research on Determining the Density of Sands by Spoon Penetration Testing,” Proceedings, Fourth International Conference on Soil Mechanics and Foundation Engineering, London, Vol. 1, pp. 35-39, 1957.
[18]Goble, G. G. and Rausche, F., “Wave Equation Analysis of Pile Foundations-WEAP86 Program,” Federal Highway Administration Report, No. FHWA/IP-86/18, USA, 1986.
[19]Goldsmith, W., “Impact,” Edward Arnold Ltd., London, 1959.
[20]Hanskat, C. S. “Wave Equation Simulation of the Standard Penetration Test”, Thesis of Master of Engineering Presented to the University of Florida at Gainesville, Florida, 1978.
[21]Ireland, H. O., Moretto, O., and Vargas, M., “The Dynamic Penetration Test：A Standard That Is Not Standardized,” Geotechnique, Vol. 20, No. 2, pp. 185-192, 1970.
[22]ISSMFE 1988, “Standard Penetration Test: International Reference Test Procedure,” International Society of Soil Mechanics and Foundation Engineering Technical Committee on Penetration Testing, Proceedings of the First International Symposium. on Penetration Testing, (ISOPT-1), Orlando, Florida, Vol. 1, pp.3-26.
[23]JIS A 1219, “Method for standard penetration test,” Japanese Standards Association, Tokyo, Japan, 1995.
[24]JIS A 1219, “Method for standard penetration test,” Japanese Standards Association, Tokyo, Japan, 2001.
[25]Kovacs, W. D. and L. A. Salomone, “SPT Hammer Energy Measurement,” Journal of the Soil Mechanics and Foundation Division, Proceedings of the American Society of Civil Engineers, Vol.108, No.GT4, pp.599-620, 1982.
[26]Kovacs, W. D., “Effects of SPT Equipment and Procedures on the Design of Shallow Foundation on Sand,” Proceedings, Settlement ’94, ASCE Geotechnical Special Publish, No. 40, Vol. 1, pp. 121-131, 1994.
[27]Lowery, L. L., “Pile Driving Analysis by the Wave Equation,” Wild West Software, Texas, 1993.
[28]McLean, F. G., Franklin, A. G., and Dahlstrand, T. K., “Influence of Mechanical Variables on the SPT,” Proceedings of the Specialty Conference on In Situ Measuremant of Soil Properties, ASCE, Raleigh, N.C. Vol. 1, pp.287-318, 1975.
[29]Middendorp, P., “Thirty Years of Experience with the Wave Equation Solution Based on the Method of Characteristics,” 7th International Conference on the Application of Stress Wave Theory to Pile, Kuala Lumur, Malaysia, 2004.
[30]Morgano, C. M., and Liang, R., “Energy Transfer in SPT- Rod Length Effect,” Proceedings, The Fourth International Conference on the Application of Stress-Wave Theory to Piles, pp. 121-127, 1992.
[31]Seed, H. B., K. Tokimatsu, L. F. Harder, and R. M. Chung, “The Influence of SPT Procedures in soil Liquefaction Resistance Evaluations,” Journal of Geotechnical Engineering, ASCE, Vol.111, No.12, pp.1425-1445, 1985.
[32]Smith, E.A.L., “Pile Driving Analysis with the Wave Equation,” Journal of Soil Mechanics and Foundation Engineering, ASCE, Vol. 86, No. SM4, pp. 35-61, 1960.
[33]Riggs, C. O., Schmidt, N. O., and Rassieur, C. L., “Reproducible SPT Hammer Imapce Force with an Automatic Free Fall SPT Hammer System,” Geotechnical Testing Journal, Vol. 6, No. 3, pp. 201-209, 1983.
[34]Riggs, C. O., G. M. Mathes, and C. L. Rassieur, “A Field Study of an Automatic SPT Hammer System,” Geotechnical Testing Journal, ASTM, Vol.7, No.3, pp.158-163, 1984.
[35]Palacios A., “The Theory and Measurement of Energy Transfer During Standard Penetration Test Sampling,” Thesis Presented to the University of Florida at Gainesville, Florida, 1977.
[36]Palmer, D. J., and Stuart, J. G., “Some Observations on the Standard Penetration Test and Correlation of the Test with a New Penetrometer,” Proceedings, Fourth International Conference on Soil Mechanics and Foundation Engineering, London, Vol. 1, pp. 231-236, 1957.
[37]Schmertmann, J. H. and A. Palacios, “Energy Dynamic of SPT,” Journal of the Geotechnical Engineering Division, ASCE, Vol.105, No.GT8, pp.909~926, 1979.
[38]Steiger, F., “AN Experimental Investigation of the Force/Penetration Relationships of Rod Impact,” Geotechnical Testing Journal, Vol. 3, No. 4, pp. 163-166, 1980.
[39]Yokel, F. Y., “Energy Transfer in Standard Penetration Test,” Journal of Geotechnical Engineering, Vol. 108, No. GT9, pp. 1197-1202, 1982.
[40]Youd, T. L., Idriss, I. M., Andrus, R. D., Arango, I., Castro, G., Christian, J.T., Dobry, R., Finn, W. D. L., Harder L. F., Hynes, M. E., Ishihara, K., Koester, J. P., Liao, S. S. C., Marcuson, W. F., Martin, G. R., Mitchell, J. K., Moriwaki, Y., Power, M. S., Robertson, P. K., Seed, R. B., and Stokoe, K. H., “Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER AND 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils,” Journal of Geotechnical and Geoenvironmental Engineering, Vol. 127, No. 10, October, 2001.
[41]王春煌、郭漢興、王如龍，「標準貫入試驗打擊能量差異產探討」，地工技術雜誌，第16期，第14-22頁，1986。
[42]陳孟助，「標準貫入試驗落錘型式對打擊能量之影響」，碩士論文，國立成功大學土木工程系，台南，1998。
[43]陳建隆，「標準貫入試驗能量檢測研究」，碩士論文，國立成功大學土木工程系，台南，1999。
[44]蔡錦松，劉衍志，周立德，劉福鎮，「標準貫入試驗與能量檢測」，地工技術，第83期，第5-12頁，2001。
[45]蔡錦松，劉衍志，「落錘型式對標準貫入試驗打擊能量之影響」，中國土木水利工程學刊，第15卷，第3期，pp. 457-466，2003。