場鑄樁樁身摩擦力及拉拔詮釋法之評估

Evaluation of Side Resistance and Uplift Interpretation Criteria for Drilled shafts

張馨文(Hsin-Wen Chang)

指導教授 ： 陳逸駿

中原大學/工學院/土木工程學系/碩士(2007年)

https://doi.org/10.6840/cycu200700763

摘要

摘要
本研究為藉由大量之樁載重試驗資料評估場鑄樁之拉拔詮釋法及樁身摩擦力，各載重資料依沿樁長之土層分為排水土層及不排水土層兩大羣分別分析。為使本分析能在較一致的基準面上進行，所選用的地工參數需能實際反應現地的載重行為。
在拉拔詮釋法方面，各代表理論基礎的詮釋法被用於本分析，同時這些詮釋結果能涵蓋上限、中間及下限的詮釋範圍。經由本分析，各詮釋法的相互關係及可靠度能予以建立。
在場鑄樁受軸向載重之樁身摩擦力方面，針對目前常使用的總應力分析α法、有效應力分析β法、混合總應力及有效應力之λ法、及經驗公式等之樁身摩擦力分析模式進行評估，透過載重試驗的實際量測值與各分析模式的理論預測值之統計比較，以瞭解各分析法之差異性及其可靠度。在完成各種分析法的適用性及可靠度後，本文亦進一步針對場鑄基樁座落於黏聚性土層及非黏聚性土層之互層土壤時之樁身摩擦力進行評估，以提供互層土壤較適當的分析模式。
本研究最後針對場鑄樁拉拔詮釋法及樁身摩擦力提出工程設計上的建議，這些建議均輔以適當的統計資料。

關鍵字

總應力法 ； 拉拔詮釋法 ； 載重試驗 ； 樁身摩擦力 ； 有效應力法 ； 場鑄樁

並列摘要

ABSTRACT

This study is a critical evaluation of uplift interpretation capacity and side resistance for the drilled shafts under axial loading. A wide variety of uplift and compression load test data are used and these data are divided into drained and undrained databases. The geotechnical and load test parameters were evaluated using updated methods that can properly reflect the field condition under load test.

In uplift interpretation capacity, representative interpretation criteria are examined to evaluate the capacity of drilled shaft foundations under axial uplift loading. These selected criteria represent a distribution of interpreted results from the lower, middle, and higher ranges as found in practice. In addition, these criteria employ varied interpretation bases. The interrelationship and reliability of each interpretation model were established.

In side resistance, representative analytical models, including the alpha, beta, lambda methods, and empirical correlation are examined in detail using both measured and predicted results to assess their relative merits and suitability for the engineering practice of drilled shaft design. With the results of side resistance in pure drained and undrained soils, the analytical models of side resistance under drained and undrained interlayer soils were further evaluated.

Specific design recommendations for the use of uplift interpretation and side resistance of drilled shafts are developed and given with the appropriate statistics to describe the quality of these recommended models.

並列關鍵字

total stress analysis ； drilled shaft foundations ； uplift loading ； side resistance ； load test ； effective stress analysis ； displacement ； interpretation criteria

參考文獻

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5. Chen, J-R and Kulhawy, FH (2002). "Axial Uplift Behavior of Pressure-Injected Footings in Cohesionless Soil", Deep Foundations (GSP 116), Ed. MW O'Neill & FC Townsend, ASCE, Reston, 1275-1289.

6. Chen, YJ and Kulhawy, FH (2002). “Evaluation of Drained Axial Capacity of Drilled Shafts”, GSP 116 ASCE, 2, 1201-1214.

9. Chin, FK (1970). “Estimation of the Ultimate Load of Piles not Carried to Failure”, 2nd Southeast Asian Conference on Soil Engineering, Singapore, 81-90.

11. Cushing, AG and Kulhawy, FH (2002). “Drained Elastic Behavior of Drilled Shafts in Cohesionless Soils”, Deep Foundations (GSP 116), Ed. MW O’Neill and FC Townsend, ASCE, Reston, 22-36.