【摘要】：在圍巖-襯砌這個封閉系統(tǒng)中,隧道的開挖和支護過程伴隨著能量的傳遞和轉(zhuǎn)化,不考慮熱能散失并將圍巖視為彈性體,則圍巖勢能的釋放即為襯砌結(jié)構(gòu)彈性應變能的增加。劉紅燕等[1-2]利用該能量守恒原理對Ⅲ級圍巖單線鐵路隧道進行了襯砌厚度的計算,在此研究成果的基礎上進一步研究了能量守恒原理對于Ⅴ級圍巖襯砌設計的適用情況。針對Ⅴ級圍巖建立FLAC3D模型動態(tài)模擬隧道的開挖過程,利用matlab語言編寫彈性應變能密度函數(shù)從而得到實體模型各單元的彈性應變能,最后得到特定范圍內(nèi)圍巖勢能隨掘進深度的變化曲線。由此圍巖勢能變化曲線可得出隧道開挖后圍巖的勢能釋放值。此外,通過進行鋼纖維混凝土(SFRC)構(gòu)件的韌性試驗,確定SFRC三分梁破壞與SFRC襯砌破壞時的能量消耗關系。據(jù)此建立能量方程并可得出SFRC襯砌的理論厚度,經(jīng)檢算,設計厚度滿足安全性要求。結(jié)果表明,能量守恒原理的隧道襯砌設計方法不再受Ⅱ、Ⅲ級圍巖小斷面情形的限制,它同樣適用于V級圍巖大斷面隧道的襯砌設計。
[Abstract]:In the surrounding rock lining closed system, the excavation and support process of the tunnel is accompanied by the energy transfer and transformation. If the heat loss is not considered and the surrounding rock is regarded as an elastic body, the release of the surrounding rock potential energy is the increase of the elastic strain energy of the lining structure. Liu Hongyan et al [1-2] calculated the lining thickness of single-track railway tunnel of grade 鈪，

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