本文關(guān)鍵詞：隧道圍巖松動壓力評估及穩(wěn)定性分析　出處：《湖南大學》2015年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 圍巖松動壓力 隧道穩(wěn)定性 RMR分類方法 數(shù)值模擬 圍巖質(zhì)量 計算高度 軟弱層

【摘要】：我國地形地貌多樣,地質(zhì)情況復雜,使得隧道成為道路的重要組成部分。松動壓力是隧道圍巖開挖后支護體系上作用的主要壓力形式之一,對隧道支護體系設(shè)計、施工及后期運營有重要影響。因此,為更好地對隧道穩(wěn)定性進行分析,本文將以該類型壓力為研究對象,總結(jié)分析并比較現(xiàn)有松動壓力分析方法。本文主要進行以下幾方面的工作:首先,對現(xiàn)有常用的隧道松動壓力計算方法進行詳細介紹,按照其提出背景進行分類。簡單分析計算方法適用條件的影響因素,為后續(xù)的計算方法研究、改進做準備。其次,對基于RMR系統(tǒng)的隧道圍巖松動壓力計算方法進行研究。對比原始RMR方法與其他巖體分類方法,明確RMR系統(tǒng)在考慮因素方面的缺失或不足。根據(jù)對比結(jié)果合理引入應(yīng)考慮因素,并對RMR方法本身的不足進行彌補,從而實現(xiàn)對RMR分類方法的合理改進。以湖南湘西某山嶺隧道為研究對象,根據(jù)設(shè)計參數(shù)確定支護體系極限承載力,并與基于改進前后RMR評估值確定的支護體系上荷載相結(jié)合,對隧道穩(wěn)定性進行分析,參考工程運營過程中的實際穩(wěn)定性狀況對改進效果進行檢驗。然后,采用數(shù)值模擬軟件FLAC3D建立隧道分析模型,分別賦予其依據(jù)改進前、后RMR值所得巖體參數(shù),進行計算、驗證。根據(jù)改進前后洞周監(jiān)測點位移與允許極限位移的關(guān)系,以及隧道模型塑性區(qū)范圍的變化情況對改進效果進行再次驗證;調(diào)整隧道模型高跨比,研究高跨比對隧道穩(wěn)定性的影響。最后,收集實際工程中發(fā)生拱形塌方隧道數(shù)據(jù),分析松動壓力計算高度與實際塌方高度的關(guān)系,并從隧道跨度、高跨比以及圍巖質(zhì)量等多方面對計算高度或塌方高度的分布形態(tài)進行歸納;通過試驗對隧道開挖過程中軟弱層的影響進行模擬分析,根據(jù)試驗隧道的塌方高度對其影響程度進行比較。
[Abstract]:Because of the diversity of topography and geomorphology and the complex geological conditions, the tunnel becomes an important part of the road. The loosening pressure is one of the main forms of pressure acting on the supporting system after the excavation of the surrounding rock of the tunnel. Therefore, in order to better analyze the stability of the tunnel, this paper will take this type of pressure as the research object. Summary and analysis of the existing loose pressure analysis methods. This paper mainly do the following work: first of all, the existing tunnel loosening pressure calculation methods are introduced in detail. According to its background classification. Simple analysis of the factors affecting the applicable conditions of the calculation method, for the subsequent study of the calculation method, to improve the preparation. Secondly. This paper studies the calculation method of loosening pressure of tunnel surrounding rock based on RMR system, and compares the original RMR method with other rock mass classification methods. It is clear that the RMR system in the consideration of the lack of factors or deficiencies. According to the results of the reasonable introduction of factors should be considered, and to make up for the shortcomings of the RMR method itself. In order to achieve the reasonable improvement of RMR classification method. Take a mountain tunnel in Xiangxi Hunan Province as the research object and determine the ultimate bearing capacity of the support system according to the design parameters. Combined with the load on the supporting system determined by the RMR evaluation value before and after the improvement, the tunnel stability is analyzed, and the improvement effect is tested by referring to the actual stability condition in the engineering operation process. The tunnel analysis model was established by numerical simulation software FLAC3D, and the rock mass parameters were calculated according to the RMR value before and after the improvement. Validation. According to the relationship between the displacement of the monitoring point around the hole and the allowable limit displacement before and after the improvement, and the variation of the plastic zone range of the tunnel model, the improved effect is verified again. Adjust the height to span ratio of tunnel model, study the influence of height to span ratio on tunnel stability. Finally, collect the data of arch collapse tunnel in actual engineering, analyze the relationship between the calculated height of loosening pressure and the actual collapse height. The distribution patterns of calculated height or collapse height are summarized from many aspects such as tunnel span, ratio of height to span and mass of surrounding rock. The influence of soft layer during tunnel excavation is simulated and analyzed by test, and the influence degree is compared according to the collapse height of test tunnel.
【學位授予單位】：湖南大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U451.2

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本文編號：1396994