- 學位論文
高性能預鑄型土釘拉出阻抗之初步研究
Preliminarily study on pullout resistance for high performance soil nail
摘要
本研究旨在探討高性能預鑄型土釘與傳統灌漿釘之拉出行為的差異。內容主要為：(1) 大型土釘拉出試驗儀之改造與實驗規劃，(2) 傳統灌漿釘與高性能預鑄釘之尖峰拉出力、行為與趨勢探討，(3) 高性能預鑄釘單一節瘤之阻抗效果，(4) 非連續型高性能預鑄釘之理想拉出力。 其結論得出: (1)傳統灌漿釘之拉出阻抗在初始拉出時發展較迅速，而高性能預鑄釘則需較大之位移量方能發展其尖峰拉出力，惟高性能預鑄型土釘之尖峰拉出力較傳統灌漿釘高約50%。(2) 高性能預鑄釘在位移30mm時之殘餘拉出力仍能保有相當優秀的效果，約為尖峰拉出力之90%，而傳統灌漿釘僅有尖峰拉出力的75~80%。(3)將高性能預鑄釘之節瘤間距調整，使其能更有效的發揮被動阻抗的優勢，其提供之拉出阻抗有明顯提升，較相同直徑下的傳統灌漿釘提高49~103.5%之拉出阻抗，且其增益效果隨釘徑越大則越明顯。(4)本研究亦以擴座節瘤之被動阻抗與主體螺桿之摩擦阻抗做理想尖峰拉出力推估，而實驗之實際尖峰拉出力卻不及理論值，原因是擴座節瘤在拉出時會造成後方砂顆粒解壓，使得後方節瘤於有限空間其被動阻抗無法同單一節瘤時完全發揮，致實際拉出力低於理論預測值。
並列摘要
The purpose of this study is to investigate the difference pullout behavior between the HPN(High performance soil nail) and the grouted nail. Main contents are:(1) Soil nail pullout test planning and transform the large equipment for soil nail pullout.(2) To discuss peak pullout force and trend of grouted nails and HPN.(3) The pullout resistance of single knot on HPN.(4)To predicted the peak force of HPNNK(High performance nail of non-continue knots). Conclusions are: (1) The pullout resistance of grouted nails at initial pullout displacement is generating faster than HPN, but the peak pullout force of HPN is about 50% higher than the grouted nails. (2)Residual resistance of HPN at 30mm pullout displacement are still kept a good effect, its effect about 90% of peak resistance, but residual resistance of grouted nails are only kept 75~80% peak resistance. (3)Adjust the spacing of the knots on the HPN, there will more space to develop passive pressure, the peak pullout force of HPNNK were 49~103.5% higher than grouted nails, the peak pullout force increases with the increase of nail diameter.(4)This study also predict the pullout force of HPNNK by passive resistance of knots and friction resistance of the screw pole, but the real peak force was lower than the predicted peak force, because the sand behind knots were decompression when knots pulling out, make the rear knots were not generating fully like the single knot, that is the reason why real peak force was lower than predicted peak force.