横向简谐荷载作用下端锚粘结式锚杆粘结受力特性试验研究

发布时间：2018-02-28 17:10

本文关键词： 横向简谐荷载锚杆固有频率粘结性衰减均匀试验设计极限锚固力　出处：《辽宁工程技术大学》2014年硕士论文　论文类型：学位论文

【摘要】：目前锚杆已广泛应用于煤矿支护工程中,由于采动荷载和爆破荷载对已有支护锚杆产生影响,因此迫切需要研究锚杆在动荷载作用下的微观力学特性及粘结性变化。本文从工程实际出发,现场监测锚杆工作状态下轴力变化和爆破荷载过程中锚杆周边围岩振动信息,并开展探索性室内试验辅以数值仿真分析。工程监测结果表明,锚杆轴力随着龄期逐渐增加后基本稳定,稳定后锚杆轴向受力约为设计锚固力的三分之一。爆破荷载作用下锚杆周边围岩三向均有振动迹象。室内试验研究结果表明,锚杆在工作状态下受到振动频率为40Hz的横向简谐荷载作用时锚杆粘结性衰减最快；同时得到40Hz20s横向振动荷载作用下锚杆粘结力变化率、振动强度和时间三者关系式,可对不同龄期不同振动荷载对粘结力产生影响进行预测。振动强度与养护龄期两个因素对新装锚杆粘结性衰减均产生影响,其中养护龄期的敏感性强于振动强度的敏感性。通过横向简谐荷载振动作用下拉拔试验可知,端锚粘结式锚杆的剪应力分布具有可传递性,锚杆的剪切应力峰值出现在锚杆锚固段的四分之一和四分之三处。对锚杆体的直径和长度进行敏感性分析,可得到锚杆长度敏感性强于锚杆尺寸敏感性。运用FLAC3D模拟软件采用室内试验参数进行模拟,其结果与室内试验结果基本吻合,同时得到拉拔破坏过程中塑性区的发展情况。
[Abstract]:At present, anchor rod has been widely used in coal mine support engineering, because of the influence of mining load and blasting load on the existing supporting bolt, Therefore, there is an urgent need to study the micromechanical characteristics and bond properties of the bolt under dynamic load. Based on the engineering practice, this paper monitors the variation of axial force in the working state of the bolt and the vibration information of surrounding rock around the bolt during blasting load. The results of engineering monitoring show that the axial force of anchor rod is stable with the increase of age. The axial force of the anchor rod after stabilization is about 1/3 of the designed anchoring force. There are vibration signs in the surrounding rock around the bolt under blasting load. When the anchor rod is subjected to the vibration frequency of 40 Hz transverse harmonic load, the bond attenuation of the anchor rod is the fastest, and the relationship among the change rate of the bolt bond force, the vibration intensity and the time under the action of 40 Hz transverse vibration load is obtained. The influence of different age and different vibration load on bond force can be predicted. Both vibration strength and curing age have influence on the bond attenuation of new anchor. The sensitivity of curing age is stronger than that of vibration strength. The shear stress distribution of end anchor bonded anchor is transmissible by drawing test under transverse harmonic load. The peak shear stress of the bolt appears at 1/4 and 3/4 of the anchoring section. The sensitivity analysis of the diameter and length of the anchor body is carried out. The length sensitivity of anchor rod is stronger than the sensitivity of bolt size. The results of FLAC3D simulation software are simulated by indoor test parameters, and the results are in good agreement with the results of indoor test, and the development of plastic zone during pullout failure is obtained.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU476

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