Mechanical properties and supporting effect of CRLD bolts under static pull test conditions
详细信息 查看全文
- 作者：Xiao-ming Sun ; Yong Zhang ; Dong Wang…
- 关键词：deep mining ; bolts ; mechanical properties ; rock support ; static pull test
- 刊名：International Journal of Minerals, Metallurgy, and Materials
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：24
- 期：1
- 页码：1-9
- 全文大小：
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Materials Science, general; Metallic Materials; Characterization and Evaluation of Materials; Ceramics, Glass, Composites, Natural Materials; Surfaces and Interfaces, Thin Films; Tribology, Corrosion
- 出版者：University of Science and Technology Beijing
- ISSN：1869-103X
- 卷排序：24
文摘
A device for supporting soft rock masses combined with a constant resistance structure characterized by constant resistance and large deformation at the end of a steel bar, known as the constant resistance and large deformation (CRLD) bolt, has recently been developed to counteract soft rock swelling that often occurs during deep mining. In order to further study the mechanical properties of the CRLD bolt, we investigated its mechanical properties by comparison with the conventional strength bolt (rebar) using static pull tests on many aspects, including supporting capacity, elongation, radial deformation, and energy absorption. The tests verified that the mechanical defects of the rebar, which include the decrease of bolt diameter, reduction of supporting capacity, and emergence and evolution of fracture until failure during the whole pull process, were caused by the Poisson’s ratio effect. Due to the special structure set on the CRLD bolt, the bolt presents a seemingly unusual phenomenon of the negative Poisson’s ratio effect, i.e., the diameter of the constant resistance structure increases while under-pulling. It is the very effect that ensures the extraordinary mechanical properties, including high resistance, large elongation, and strong energy absorption. According to the comparison and analysis of numerical simulation and field test, we can conclude that the CRLD bolt works better than the rebar bolt.