【摘要】：通過室內模型試驗對3榀不同位置設置可縮接頭的U型鋼馬蹄形封閉可縮鋼架進行分級均布加載,并采集不同荷載下鋼架不同位置的徑向位移及各接頭滑移量.結果表明:1)接頭滑移速率決定鋼架承載力及其變形特性,接頭快速滑移時鋼架承載力不穩(wěn)定性增加,讓壓變形明顯;2)封閉可縮鋼架接頭滑移特性與接頭處鋼架內力組合有關,隨總外荷載的增加,拱頂接頭最先發(fā)生滑移且速率較快,其次為拱腳接頭,拱底接頭最難滑移;3)拱頂接頭發(fā)生滑移時拱頂下沉最為明顯,建議當圍巖荷載頂壓較大時優(yōu)先在拱頂設置接頭;當圍巖側壓力較大時,宜在拱底設置接頭;4)在不削弱鋼架支護力的前提下保證所有可縮接頭平穩(wěn)有效滑移是充分發(fā)揮其讓壓支護性能的關鍵.
[Abstract]:Through indoor model test, three U-shaped steel horseshoe closed retractable steel frames with retractable joints in different positions were graded and uniformly loaded, and the radial displacement and slip displacement of different positions of the steel frame under different loads were collected. The results show that: 1) the bearing capacity and deformation characteristics of the steel frame are determined by the slip rate of the joint, and the instability of the bearing capacity of the steel frame increases when the joint slips rapidly, which makes the compression deformation obvious; 2) the slip characteristics of the closed retractable steel frame joint are related to the internal force combination of the steel frame at the joint. With the increase of the total external load, the arch roof joint first slips and the rate is faster, followed by the arch foot joint, and the arch bottom joint is the most difficult to slip. 3) when the arch roof joint slips, the arch roof subsidence is the most obvious, so it is suggested that the joint should be set up at the arch bottom when the load top pressure of the surrounding rock is large, and when the side pressure of the surrounding rock is large, the joint should be set up at the bottom of the arch. 4) the key to give full play to the performance of compression support is to ensure the smooth and effective slip of all retractable joints without weakening the support force of steel frame.
【作者單位】： 交通運輸部公路科學研究院;北京航空航天大學交通科學與工程學院;
【基金】：國家自然科學基金資助項目(51278233) 交通運輸部公路科學研究所基金項目(2015-9033)
【分類號】：U451.5
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本文編號：2493068