【作者】 姚显春；

【导师】 李宁； 陈蕴生；

【作者基本信息】 西安理工大学 ， 岩土工程， 2005， 硕士

【摘要】 锚杆支护广泛地应用于各项工程中,对锚杆工作机理的现场试验、室内试验等定性研究已有很多报道,但系统的量化机理及量化设计方法尚未见报道。在锚杆工作机理的研究中,用有限元分析方法进行系统量化研究还远远不够。本文借助有限元方法在锚杆支护内力和围岩应力、变形方面的特有优势,以数值分析作为研究的方法,以“数值仿真试验”作为研究手段和工具,对锚杆支护进行了系统的数值试验研究。首先,研究了锚杆拉拔试验中极限抗拔力与界面粘结强度的关系;在分析锚杆抗拔试验传力机理的基础上,对地下洞室锚杆受力机理进行了理论分析,建立了实际工作状态下锚杆的受力分析模型。然后,对照拉拔试验数值分析,建立了能够正确反映锚杆支护性状的数值试验模型,对含软弱层地下洞室的锚杆支护进行了系统的数值仿真试验,从支护结构内力和变形及围岩的变形揭示了锚杆支护的加固机理。最后,研究了参数对锚杆受力及支护效果的影响,进一步探讨了锚杆一岩体相互作用的机理和支护结构的特征规律,为优化设计提出了更为合理的支护参数取值。主要研究结沦有:西安理工大学硕士学位论文 1、对拉拔试验中锚杆一岩体相互作用机理进行理论分析,建立了“极限拉拔力”和“界面枯结强度”的关系。 2、推导出了隧洞锚杆受力分析模型,对分析锚杆的力学特征及其影响因素有一定的意义.为猫杆的设计和计算提供了一种理论依据。 3、对含软弱层地下洞室的锚杆支护,从支护结构内力和变形及围岩的变形揭示了锚杆支护的叩固机理。 4、探讨了锚杆一岩体相互作用的机理和支护结构的特征规律,为优化设计提出了更为含理的支护参数取值。 关键词:锚杆支护分析模型软弱夹层加固机理更多还原

【Abstract】 Bolt support system has been applied widely in Geotechnical engineering ,but the research on work mechanism and designing method of bolt is mainly performed by lab experiment and in-situ tests .It is still a shortage of utilizing FEM method to study the detail properties of the bolted rock mass.In this paper, the systemic numerical tests on bolt support are made utilizing FEM method focused on the influence of bolts to inner force of supporting structure and the rock stress and deformation properties.Firstly, the relation between the ultimate tensile of the bolt and interface cohesive intensity between the bolt and rock is analyzed through the pulling-out test, on the basis of analyzing mechanism of bolt spreading force, an analytical model is proposed to predict the axial force and shear stress on the grouted bolt surface for tunnel bolting. Then compared with data of pulling-out test of bolt ,a numerical test model which embody correctly condition of bolt supporting is set up. The systemic numerical tests on bolt support in tunnels with weak interbed are then carried out, and the reinforce mechanism of bolt support are discussed. Finally , through researching the influence of parameters on bolt bearing capacity and supporting effect, the interaction behaviors of the rock bolt and rock mass his further described. Main conclusions can be:1、 The interaction mechanism of the rock bolt and rock mass is theoretically analyzed in pulling-out tests and the relationship between the ultimate tensile force and interface cohesive intensity is established.2、 AN analytical model to predict inner force on grouted rock bolt for tunneling is also proposed, it is meaningful to describe the mechanics characteristics of bolt and its main factors on mechanics characteristic of bolt.3、 Through analyzing inner force and distortion of the supporting structure and rock mass, the reinforce mechanism of bolt support are further described4、 The interaction mechanism of the rock bolt and rock mass change law of inner force and distortion about supporting structure is also described, to provide a quantitative evaluation for bolt supporting effect.更多还原