【摘要】：公路隧道因其具有良好的克服地形障礙、縮短路線里程的優(yōu)勢(shì),發(fā)展相當(dāng)迅速。隧道在建設(shè)過(guò)程中,初襯是隧道支護(hù)結(jié)構(gòu)中的重要部分,是前期施工的主要受力結(jié)構(gòu)。若初期支護(hù)施工質(zhì)量不過(guò)關(guān),會(huì)導(dǎo)致隧道結(jié)構(gòu)變形,造成二襯結(jié)構(gòu)開(kāi)裂,嚴(yán)重者甚至導(dǎo)致坍塌,因此對(duì)隧道初期支護(hù)的監(jiān)測(cè)必不可少。新奧法是目前國(guó)內(nèi)外最常用的隧道施工方法,而爆破又是新奧法的重要施工環(huán)節(jié)。圍巖爆破后將產(chǎn)生巨大的能量,將會(huì)以應(yīng)力波的形式向遠(yuǎn)處傳播,并引起圍巖和支護(hù)結(jié)構(gòu)振動(dòng),這將造成圍巖質(zhì)量降低,同時(shí)還會(huì)造成支護(hù)結(jié)構(gòu)受損。但是,應(yīng)力波在傳播的過(guò)程中的強(qiáng)度會(huì)隨距爆源距離的增加而減小,故在一定的范圍內(nèi),圍巖爆破可能對(duì)初襯支護(hù)造成影響。因此,基于圍巖爆破對(duì)初襯變形進(jìn)行研究,了解爆破的影響范圍,對(duì)于隧道監(jiān)測(cè)有著重要的意義。依托龍永高速公路建設(shè)項(xiàng)目,分析了隧道初襯變形的影響因素,通過(guò)變形監(jiān)測(cè)數(shù)據(jù)論證爆破擾動(dòng)是影響隧道初襯變形的主要因素。研究了不同圍巖級(jí)別條件下爆破擾動(dòng)的影響范圍,將其引入變形監(jiān)測(cè)模型中,探討優(yōu)化了已有預(yù)測(cè)模型。通過(guò)對(duì)監(jiān)測(cè)數(shù)據(jù)的分析,發(fā)現(xiàn)將影響范圍以外的點(diǎn)的變形值作線性擬合處理更符合實(shí)際。據(jù)此,應(yīng)用分段函數(shù)將兩者進(jìn)行組合建立優(yōu)化模型,實(shí)例證明,用分段函數(shù)構(gòu)建的預(yù)測(cè)模型能很好地提高預(yù)測(cè)精度。依據(jù)爆破擾動(dòng)主導(dǎo)性論證優(yōu)化了監(jiān)測(cè)時(shí)間點(diǎn),分析指出在爆破后測(cè)量的監(jiān)測(cè)數(shù)據(jù)更能反映實(shí)際變形。對(duì)爆破擾動(dòng)影響范圍的研究,旨在確定二襯的合理施工時(shí)機(jī)。根據(jù)研究成果提出了基于影響范圍確定二襯到掌子面距離的方法,為二襯施工提供了參考。
[Abstract]:Highway tunnel has developed rapidly because of its advantages of overcoming terrain obstacles and shortening route mileage. In the process of tunnel construction, primary lining is an important part of tunnel supporting structure and the main force structure in early construction. If the construction quality of the initial support is not up to standard, it will lead to the deformation of the tunnel structure, the cracking of the second lining structure, and even the collapse of the secondary lining structure, so it is necessary to monitor the initial support of the tunnel. New Olympic method is the most commonly used tunnel construction method at home and abroad, and blasting is an important construction link of the new Olympic method. After blasting the surrounding rock will produce huge energy which will propagate to the distance in the form of stress wave and cause the vibration of surrounding rock and support structure which will cause the mass of surrounding rock to be reduced and the supporting structure will be damaged at the same time. However, the strength of the stress wave decreases with the increase of the distance from the explosion source, so the surrounding rock blasting may affect the primary lining support in a certain range. Therefore, it is of great significance for tunnel monitoring to study the influence of blasting on initial lining deformation based on surrounding rock blasting. Based on the Longyong Expressway construction project, this paper analyzes the influence factors of tunnel initial lining deformation, and proves that blasting disturbance is the main factor affecting tunnel initial lining deformation through deformation monitoring data. In this paper, the influence range of blasting disturbance under different surrounding rock levels is studied, which is introduced into the deformation monitoring model, and the existing prediction model is discussed and optimized. Through the analysis of the monitoring data, it is found that the deformation value of the point outside the range of influence is more suitable for the practice. Based on this, the optimization model is established by combining the two models with piecewise function. The example shows that the prediction model constructed by piecewise function can improve the prediction accuracy very well. The monitoring time points are optimized according to the dominant proof of blasting disturbance, and it is pointed out that the monitoring data measured after blasting can better reflect the actual deformation. The study on the influence range of blasting disturbance is aimed at determining the reasonable construction time of the second lining. Based on the research results, a method for determining the distance between the two linings and the palm-face is proposed, which provides a reference for the construction of the second linings.
【學(xué)位授予單位】：長(zhǎng)沙理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：U456.3
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本文編號(hào)：2307665