查詢結果分析
來源資料
頁籤選單縮合
題 名 | 不同退縮距離對膠結不良砂岩之淺基礎承載行為之影響=Effect of Setback Distance on Loading Behavior of Shallow Foundation in a Poorly Cemented Sandstone |
---|---|
作 者 | 張振成; 廖志中; 潘以文; 孫光東; 王柏皓; | 書刊名 | 臺灣公共工程學刊 |
卷 期 | 2:1 民95.06 |
頁 次 | 頁13-21 |
分類號 | 441.1 |
關鍵詞 | 軟岩; 模型承載試驗; 退縮距離; 承載行為; 破壞機制; Soft rock; Foundation mode for loading test; Setback distance; Bearing behavior; Failure mechanism; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究旨在由室內模型承載試驗結果,探討基腳位於無邊坡滑動破壞之虞條件下之膠結不良砂岩邊坡,不同退縮距離對承載行為與破壞機制的影響。研究方法是以模擬地層(頭嵙山層)通過30號篩之砂岩屑粒來當作主要模擬材料,經師篩後含細粒料水溶液為膠結材,依配比混合攪拌,經由高壓壓密方式製作試體。待試體氣乾後,以人工削磨方式製作邊坡傾角20度之試體,分別將基腳放置距波頂1倍及2.5倍基礎寬度位置,進行承載試驗並觀察記錄承載行為與破壞過程。經研究結果顯示,承載曲線可略分為四個階段,即應力調整階段、線性階段、非線性階段及破壞階段,基礎承載行為隨退縮距離增加而不同。基礎破壞模式可分為基腳正下方三角楔形之主動壓力區,最外側鄰近地表面之被動壓力區,於此兩區間傳遞應力區域為應力轉折區。基礎破壞機制為基腳下方主動壓力區向兩側推擠時,基礎破壞較集中於邊坡側發展,且邊坡處被動壓力區及應力轉折間之裂縫開裂擴大且相互連通而形成破壞滑動面,基腳下方主動區即因失去側向支撐,向邊坡處滑動而達極限承載力。基礎承載力隨基腳位置不同而改變並隨退縮距離增加,承載力隨之漸增,當基礎與邊坡之距離約大於2.5倍基腳寬度時,其極限承載力接近水平地表條件者,但其承載行為與破壞機制仍受邊坡地形所影響。 |
英文摘要 | This study aims to investigate the effect of setback distance on the loading behaviors of the shallow foundation located on the crest of a slope of poorly cemented sandstone. Based on the loading curves and the phenomena of crack development during loading, the effect of setback distance of foundation bearing stress and the failure mechanisms are explored. From the observation, the foundation rock after failure can be categorized in three zones, the triangular active zone beneath the footing, the outer passive zone near the free surface and the transition zone between both. For a footing located on a horizontal ground, a symmetric failure mode with respect to the footing is observed at the foundation rock. Due to the existence of a slope, the failure mode of foundation rock for footing located on a crest an inclined ground is different with the footing on a horizontal surface. Because the volume of active zone at the slope side is less than that in the side of level ground, major fractures are developed at the active zone of the slope side. Consequently, the passive and transition zones connect and induce ruptures in the slope side. The ultimate bearing stress measured is due to lack of lateral support at the slope side, meanwhile the rock in the level ground side does not contribute to the bearing stress. Based on the experimental results, the fact reflects that the bearing capacity of the foundation on the slope crest varies with its setback distance. The bearing capacity increases with the increase of the setback distance. The slope will not influence the bearing capacity while the failure surface does not extend to the slope. According to the results of loading tests conducted in this study, the bearing capacity is independent of the slope when the setback stance is more than 3 times of the width of the foundation (15cm). |
本系統中英文摘要資訊取自各篇刊載內容。