围岩爆破对隧道初衬变形影响监测及预测模型研究
发布时间：2018-11-03 11:33
【摘要】：公路隧道因其具有良好的克服地形障碍、缩短路线里程的优势,发展相当迅速。隧道在建设过程中,初衬是隧道支护结构中的重要部分,是前期施工的主要受力结构。若初期支护施工质量不过关,会导致隧道结构变形,造成二衬结构开裂,严重者甚至导致坍塌,因此对隧道初期支护的监测必不可少。新奥法是目前国内外最常用的隧道施工方法,而爆破又是新奥法的重要施工环节。围岩爆破后将产生巨大的能量,将会以应力波的形式向远处传播,并引起围岩和支护结构振动,这将造成围岩质量降低,同时还会造成支护结构受损。但是,应力波在传播的过程中的强度会随距爆源距离的增加而减小,故在一定的范围内,围岩爆破可能对初衬支护造成影响。因此,基于围岩爆破对初衬变形进行研究,了解爆破的影响范围,对于隧道监测有着重要的意义。依托龙永高速公路建设项目,分析了隧道初衬变形的影响因素,通过变形监测数据论证爆破扰动是影响隧道初衬变形的主要因素。研究了不同围岩级别条件下爆破扰动的影响范围,将其引入变形监测模型中,探讨优化了已有预测模型。通过对监测数据的分析,发现将影响范围以外的点的变形值作线性拟合处理更符合实际。据此,应用分段函数将两者进行组合建立优化模型,实例证明,用分段函数构建的预测模型能很好地提高预测精度。依据爆破扰动主导性论证优化了监测时间点,分析指出在爆破后测量的监测数据更能反映实际变形。对爆破扰动影响范围的研究,旨在确定二衬的合理施工时机。根据研究成果提出了基于影响范围确定二衬到掌子面距离的方法,为二衬施工提供了参考。
[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.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U456.3
，
本文编号：2307665
[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.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U456.3
，
本文编号：2307665
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