摘要：Due to the influence of mining disturbance stress,it is of great significance to better understand the bearing characteristics of fully grouted bolts under different pull-out loading *** this purpose,a series of laboratory pull-out tests were conducted to comprehensively investigate the effects of different pull-out loading rates on the mechanical performance and failure characteristics of fully grouted *** results show that the mechanical performance of the anchored specimen presents obvious loading rate dependence and shear enhancement *** the increase of the pull-out loading rates,the maximum pull-out load increases,the displacement and time corresponding to the maximum pull-out load *** accumulated acoustic emission(AE)counts,AE energy and AE events all decrease with the increase of the pull-out loading *** AE peak frequency has obvious divisional distribution characteristics and the amplitude is mainly distributed between 50-80 *** the increase of the pull-out loading rates,the local strain of the anchoring interface increases and the failure of the anchoring interface transfers to the interior of the resin *** accumulated AE counts are used to evaluate the damage parameter of the anchoring interface during the whole pull-out *** analytical results are in good agreement with the experimental *** research results may provide guidance for the support design and performance monitoring of fully grouted bolts.

摘要：预制节段拼装桥墩存在施工周期短,对交通和环境影响小等优势。随着经济的快速发展和城市化进程的加快,车辆撞击桥墩的事件增加,在极端情况下可能还会导致桥梁整体倒塌。然而,关于这种结构形式的抗车辆撞击性能研究仍较为匮乏,因此,非常有必要开展这方面的研究。该文基于显式动力分析软件ANSYS/LS-DYNA对车辆撞击预制混凝土节段拼装桥墩开展数值模拟工作,在保证数值模型合理性与准确性的基础上,探究几何与构造等因素对节段拼装桥墩抗车辆撞击性能的影响,具体包括截面类型、预应力筋以及剪力键布置等。结果表明:圆形截面相比于方形截面具有更好的抗车辆撞击性能;周边布置预应力筋相较于中心布置能够给节段拼装桥墩提供更好的抗车辆撞击性能;圆柱形混凝土剪力键能够通过提高节段拼装桥墩的整体性来提升节段拼装桥墩的抗车辆撞击性能。基于研究结果的综合考虑,对于实际工程应用问题,应将预制拼装桥墩按圆形截面设计,并采用周边布置预应力筋及节段中心布置剪力键的形式。