【作者】 徐晨；

【导师】 陈建勋；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 目前,锁脚锚杆(管)越来越多地应用于软弱围岩隧道建设中,它能有效控制隧道初期支护的下沉,对维持隧道结构的稳定性起着重要作用。然而,在隧道设计、施工中对锁脚锚杆的规格、打设方向、长度、数量等支护参数的选取尚处在经验摸索阶段,有关锁脚锚杆(管)的支护效果、作用机理方面未能进行系统的研究和总结。本文在研究锁脚锚杆(管)作用机理的基础上,应用有限元分析软件MIDAS/GTS对软弱围岩隧道中采用锁脚锚杆(管)时的支护效果进行数值模拟和计算,考虑锁脚锚杆(管)在不同打设角度、不同长度、不同数量等方面对隧道周边围岩变形的影响,通过对各影响因素与隧道拱顶沉降、净空收敛及锚杆轴力之间关系的分析,其计算结果表明,随锁脚锚杆与水平方向夹角的增加,拱顶下沉量逐渐减小,净空收敛量逐渐增大,且拱顶下沉、净空收敛均随锁脚锚杆长度的增加逐渐减小。通过对各级软弱围岩隧道中不同数量锁脚锚杆对隧道支护效果进行对比分析,优化给出在Ⅳ级围岩隧道中宜采用单排锁脚锚杆；在V级围岩隧道中宜采用双排锁脚锚杆；在Ⅵ级围岩隧道中宜采用三排锁脚锚管。此外,通过对包家山隧道、明垭子隧道和天恒山隧道试验断面锁脚锚杆(管)的现场监测数据与有限元模拟计算结果进行对比分析,结果表明锁脚锚杆(管)在隧道工程中的使用可以有效地提高整体结构的安全性与稳定性。本文给出各种围岩条件下的锁脚锚杆(管)最优设置方案可作为类似工程设计的参考依据,其计算方法也为工程设计提供了较好的借鉴作用,对目前隧道工程建设具有重要的意义。更多还原

【Abstract】 At present, the Feet-lock bolt (tube) is increasingly used in soft rock tunnel construction, it can control the sinking of the tunnel primary support effectively, the maintenance of the stability of tunnel structure plays a role in reuse. However, in the tunnel design and construction, the specifications, direction, length, volume and other support parameters of the feet-lock bolt (tube) is still groping in the experience of the stage. The supporting effect and mechanism of the feet-lock bolt (tube) hadn’t researched and concluded systematically.In this paper, based on the system research of the feet-lock bolt (tube) mechanism, using the finite element analysis software MIDAS/GTS to numerically simulate and compute the feet-lock bolt (tube)support effect in soft rock tunnel, considering the effect of rock deformation around tunnel caused by the feet-lock bolt (tube) on different angles, different length and different quantity, through the analysis between various influent factors and the tunnel crown settlement, clearance and bolt axial force, the results show that, with the angle increases between Feet-lock bolt and horizontal, dome subsidence decreases, clearance convergence volume increases, and the vault settlement, clearance convergence gradually reduced with foot anchors length increases.Through the soft rock at all levels, the number of foot anchors of different support effects of tunnel were analyzed to optimize is given in gradeⅣrock tunnel should adopt the single-row foot anchors; in V grade rock tunnel should adopt the double foot anchors; inⅥlevel of suitable rock tunnel in three rows of lock pin anchor tube.In addition, through the comparative analysis of the feet-lock bolt (tube) at the tunnel test section between on-site monitoring data and finite element simulation results on the tunnel of BaoJiashan, MingYazi and TianHengshan, to verify the use of feet-lock bolt (tube) can effectively improve the overall security and stability of the tunnel structure.In this paper, a variety of the feet-lock bolt (tube) best parameters can be designed as a reference for similar projects, the calculation methods provides a better reference for the engineering design, it has important significance for the current construction of the tunnel project.更多还原