英文篇名
DETERMINATION OF IN SITU STRESS IN ROCK MASS BY OVERCORING METHOD
作者
石作泯、鄧博維、劉振維、蕭富元
關鍵字
三分量孔內變形儀、套鑽法、地下坑室、現地應力
摘要
由於工程建設的推動,各種地下開挖工程日益普遍,其中現場地應力之大小、方向分佈狀態,以及岩層開挖後應力重新分佈之情況,對地下開挖工程的品質及安全穩定均有極重要立影響。因而本研究乃挑選套鑽法中之USBM法(Overcoring USBM Type Method)來進行對現地應力及變形之量測研究,並以花蓮聯峯石礦場地下坑室做為實際量測研究地點﹔其中包括三個鑽孔之套鑽實驗、雙軸試驗、Factor校正、以及理論地應力分析、量側面應力狀態分析、三維空間主應力分佈計算等。
由實驗結果得知,一個典型的套鑽USBM實驗過程,其量側面徑向變形量和套鑽探度之關係如下:剛開始套鑽時其變形量極小,可是當靠近量測面深度時,徑向變形量產生急劇之變化,而最終達相當深度時變形量又趨於穩定不再變化。坑室開挖所造成之應力集中方面,由於資料點不足,其應力集中影響範圍不甚顯著。
英文摘要
Based on the 6-years planning of the National Construction, many of the large scale underground engineering projects are developed step by step during the past few years, such as the underground free way tunnels, railway tunnels and the underground stope mining etc. The essential problems for these projects which, affecting the quality and safety concern of underground engineering are the in-situ field stress conditions, such as the magnitude, direction and the redistribution of the field stresses during excavation. The investigation of the in-situ field stress conditions of the underground engineering construction is the first considerations for solving the above problems.
The overcoring tests, using the whole set of the USBM deformation gauges for measuring the magnitude and the directions of the max. and min. principal field stresses, were carried out in the under ground stopes of the Lien-Foung Dolomite mines and the 3-D principal stresses were also analyzed from the data of overcoring tests using the matrix method.