Boulanger and Idriss之CPT-based與SPT-based液化分析結果之探討

Comparison of Boulanger and Idriss CPT-based and SPT-based liquefaction assessing methods based on the Tainan dataset

張哲偉(Che-Wei Chang)

指導教授 ： 古志生

義守大學/工學院/土木工程學系/碩士(2023年)

摘要

圓錐貫入試驗(Cone penetration test, CPT)與標準貫入試驗(Standard penetration test, SPT)為大地工程界最普遍之地質調查試驗，兩者間各有優缺點，也發展各種不同的液化評估法，但每項評估法分析結果都有所不同。為了探討標準貫入試驗與圓錐貫入試驗之液化評估法之一致性，本研究嘗試以Boulanger and Idriss之液化分析評估方法探討兩者間的一致性。
本研究利用台南十個平行調查點進行地質調查分析土壤液化潛勢，圓錐貫入試驗進尺速率為20±5 mm/sec，每隔 5cm深度記錄一筆資料，每一筆資料包括錐尖阻抗(cone resistance, qc)、摩擦阻抗(sleeve friction, fs)及孔隙水壓(pore water pressure, Pw 或 u2)三種數據，標準貫入試驗與取樣通常間隔 100 - 200cm 進行乙次，SPT-N 值為貫入 30 公分的累積打擊數SPT-N值，本研究嘗試將圓錐貫入試驗每5公分一筆之數據以土層平均數方式與標準貫入試驗貫入30公分之數據進行探討。兩項試驗以Boulanger and Idriss之CPT-based與SPT-based液化評估分析結果表明，在土層變化處會影響CPT之數據，但CPT試驗與SPT試驗一同評估也可發現SPT-N值在土從變化處會有被高估現象。
利用日本學者Iwasaki於1984年所提出之液化潛能指數(Liquefaction Index,LPI)作為標準分析液化潛能，BI-CPT結果皆為高液化潛勢，與BI-SPT液化分析法共有五點位相同，其餘五點為中液化潛勢。台南市地調所與中央經濟部地質調查所之評估方式分別為HBF(雙曲線函數法)及JRA(日本道路協會簡易經驗法)之SPT-based法，三種SPT-based法之評估結果除了三個高液化潛勢相同之外，SW021之評估結果亦完全相同為中液化潛勢，另外六個調查點之評估結果有所差異。

關鍵字

標準貫入試驗 ； 圓錐貫入試驗 ； 液化潛能指數

並列摘要

Cone penetration test (CPT) and standard penetration test (Standard penetration test, SPT) are the most common geological survey tests in the field of geoengineering. Both have their own advantages and disadvantages, and various liquefaction evaluation methods have been developed. The results of each assessment method analysis are different. In order to explore the consistency between the liquefaction evaluation method of the standard penetration test and the cone penetration test, this study attempts to explore the consistency between the two using the liquefaction analysis evaluation method of Boulanger and Idriss.
The footage rate of the cone penetration test was 20±5 mm/sec, and a piece of data was recorded every 5cm depth. Each piece of data included cone resistance (qc), friction resistance (sleeve friction, fs) and pore water pressure (pore water pressure). pressure, Pw or u2) three kinds of data, the standard penetration test and sampling are usually carried out twice at an interval of 100-200cm, and the SPT-N value is the cumulative number of blows penetrating 30 cm. The data of one stroke is discussed with the average number of soil layers and the data of the standard penetration test penetrating 30 cm. The results of the two tests based on the CPT-based and SPT-based liquefaction evaluations of Boulanger and Idriss show that changes in the soil layer will affect the CPT data, but the CPT test and the SPT test can also be evaluated together. Changes can be overestimated.
IWASAKI in 1984 (Liquefaction Index, LPI) as an analysis of liquefaction, Bi-cpt Ppt result potential, and five points as potential. The evaluation methods of the Tainan City Geological Survey Institute and the Geological Survey Institute of the Central Ministry of Economic Affairs are respectively: Result also Also exactly the same as the liquefaction potential. Another six survey points.

並列關鍵字

none

參考文獻

[1] R.W.BOULANGER I.M.IDRISS, CPT AND SPT BASED LIQUEFACTION TRIGGERING PROCEDURES, 2014.

[2] P. K. Robertson and K.L. Cabal (Robertson), Guide to Cone Penetration Testing for Geotechnical Engineering, 2014.

[3] I. M. IDRISS R. W. BOULANGER, SPT-BASED LIQUEFACTION TRIGGERING PROCEDURES, 2010.

[4] I.M. Idriss, R.W. Boulanger, Semi-empirical procedures for evaluating liquefaction potential during earthquakes, Soil Dynamics and Earthquake Engineering 26 (2006) 115–130, 2004.

[5] TOSHIO IWASAKI, TADASHI ARAKAWA and KEN-ICHI TOKIDA, Simplified procedures for assessing soil liquefaction during earthquakes, 1984.