應用禁忌演算法於超微粒水泥漿體滲透灌漿之可灌性研究

Abstract

本研究藉由所收集之240筆現地資料，以傳統相對粒徑比可灌性經驗公式，與禁忌演算法，進行可灌性之預測分析。傳統經驗公式之預測準確率為45%至68%，明顯可看出其對於超微粒水泥滲透灌漿於砂性粉土層無法有效預測。而禁忌演算法以傳統可灌性公式裡的土壤有效粒徑(d10)、土壤有效粒徑(d15)、超微粒水泥粒徑(D85)、超微粒水泥粒徑(D95)重新定義公式的N值範圍，建構一適合台灣地區高細粒料含量之砂性粉土層超微粒水泥滲透灌漿可灌性的預測公式。依據本研究之分析結果顯示，以Krizek et al. (1992)公式修正得知N1>2且N2>1時為可灌，且此預測公式有較佳的預測能力，準確率高達90.83%。 此外，為瞭解資料參數的不確定性，本研究利用拔靴法做不確定性分析，結果顯示N1門檻值與N2門檻值，其1000組拔靴樣本的平均值與標準差皆符合禁忌演算法推估模式求得之結果，顯示參數不確定性極小，且本預測公式應為可行的。 本研究亦進行室內滲透灌漿試驗，採用與現地資料相同之水灰比(3.34、4.0及4.65)、水泥之爐石含量50%及不同細粒料含量(0%、10%、20%、30%、40%)之砂柱試體，用以針對預測公式進行驗證，結果顯示，其可灌性預測準確率可達80%。 由本研究之可灌性預測公式及結果分析，前人所提出之經驗公式，對於超微粒水泥滲透灌漿於砂性粉土層之可灌性，明顯無法有效的推估。而應用禁忌演算法來建立可灌性預測公式，重新訂定公式的門檻值為相當可行之方法。

In this study, 240 sets of field data were collected and analyzed to evaluate the groutability by using two methods, namely the conventional formula with relative particle size ratio and the tabu search algorithm (TS). The accuracy of the conventional formula method ranged from 45% to 68%, i.e., this method can not be successfully used to predict the groutability. Tabu search algorithm used four factors：the effective soil particle size ,(d10), the soil particle size ,(d15), the microfine cement partical size ,(D85) and the microfine cement partical size ,(D95) to redefine the groutability limits of the conventional empirical formula. These factors were used to establish a suitable prediction formula which can predict the groutability of permeation grouting with microfine cement grout to the sandy silt soils with high fines content in Taiwan. From the obtained results, it was found that the microfine cement could grout to the sandy silt soils while N1>2 and N2>1, and the prediction formula showed a better forecast ability with an accuracy as high as 90.83%. Aside from these, in order to realize the parameter uncertainty, this study used bootstrap method to carry out uncertainty analysis. The results revealed that the mean values and the standard deviations of 1000 bootstrap samples of the groutability limits fit the results derived from tabu search algorithm model. It indicated that the parameter uncertainty can be neglected and the prediction formula is feasible. In this study, the permeation grouting experiments were also conducted in the laboratory. The water-to-cement ratio were controlled to be 3.34, 4.0 and 4.65, which were the same as the value used in the field. The slag content of the microfine cement was 50% and five different contents of fines, namely, 0%, 10%, 20%, 30% and 40%, were used. Using the data obtained from the permeation grouting experiments, the prediction formula were verified and its accuracy reached 80%. According to the results of this study, the conventional formula method could not be successfully used to predict the groutability of the permeation grouting with microfine cement grout to sandy silt soils. However, using tabu search algorithm to construct the prediction formula by redefining the groutability limits showed its superiority and practicality.