地工合成材應用於提升淺基礎承載力之室內試驗

Laboratory Testing on Enhancing the Bearing Capacity of Shallow Foundation by Geotextile

賴國豪(Guo-Hao Lai)

指導教授 ： 賴俊仁

朝陽科技大學/理工學院/營建工程系/碩士(2014年)

摘要

加勁土壤在大地工程上之運用由來已久，對於承載力較弱之土層常加入地工合成材，利用地工合成材與土壤間的互制關係，達到提高承載力的效果。目前國內有關加勁材料應用的研究多著重於擋土結構或加勁邊坡，而有關於加勁淺基礎方面之研究並不多見。
本研究延續前人(鍾劭一)之數值模擬研究，進行加勁淺基礎承載力提升效果之室內模型試驗，試驗槽尺寸為90cm(L)×90cm(W)×100cm(H)，以油壓載重設備加壓85cm(L)×10cm(W)×5cm(H)之條型基礎。先進行未加勁條型基礎之承載力試驗，再改變不同的參數(埋置深度、延伸長度、層間距離)以得知各加勁條件下條型基礎承載力之提升效果，做為日後工程設計參考。
試驗結果顯示，加勁材最佳埋置深度為0.4倍基礎寬度，此時承載力提升效果(BCR)值達1.67倍，延伸長度為3倍基礎寬度時BCR值達1.81倍，與前人(鍾劭一)數值模擬結果最佳埋置深度0.4倍基礎寬度時BCR值為1.55倍，最佳延伸長度3倍基礎寬度時BCR值為1.55倍結果相符合，由此可證於淺基礎下方置入加勁材，可使淺基礎承載力有明顯之提升，所以地工合成材料非常適合解決淺基礎於軟弱土壤承載力不足之問題。

關鍵字

承載力 ； 淺基礎 ； 加勁土壤 ； 地工合成材

並列摘要

Reinforced soils have been used in the earth works for a long time. The strength of the soils are increased by the interaction between the geotextiles and soils. The geotextiles have long been used in earth retaining structures, but relatively little studies have been performed on reinforced shallow foundations.
This thesis extends the previous study performed by Shao-Yi Chung (2011) Laboratory tests were conducted to study the improvement of bearing capacity of shallow foundations reinforced by geotextile. The dimensions of the test cell are 90cm (L) × 90cm (W) × 100cm (H). A hydraulic loading system is used to apply the normal force to a (L) × 10cm (W) × 5cm (H) stripe footing. The unreinforced bearing capacity was obtained first and was compared with value calculated using Terzaghi’s equation. Various parameters such as: the burial depth of the reinforcement, the length of the reinforcement, the number of layers and the distance between layers were varied to investigate the improvement of bearing capacity.
Results of this study indicate that the optimum burial depth of the reinforcement is about 0.4 times the width strip footing, with a bearing capacity ratio(BCR) of about 1.67. The optimum reinforcement length is about 3 times the width of the strip footing with a BCR value of 1.81. Results of this study are in accord with previous numerical simulations performed by Shao-Yi Chung.

並列關鍵字

Bearing capacity ； Shallow foundation ； Reinforced soil ； Geotextiles

參考文獻

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