Comparative Study on the Anchor Performance of Wooden Tension Anchor Bolts and Tension–Compression Composite Anchor Bolts in Earthen Sites

ABSTRACT

The full-length bond wood tensile anchor system (WTS) conventionally used in earthen sites is primarily broken by the debonding of the bolt–slurry interface. To solve this limitation, material performance and pull-out tests were performed for a new type of wood tension–compression composite anchor system (WTCS) and WTS, and the strain of the bolt–slurry and the slurry–soil interface were monitored. A comparison of test results indicated the following: The average pull-out force of the WTCS is approximately 23–51% higher than that of the WTS. The WTCS has the strong ductility characteristics of small elastic and large plastic deformation. As the load increases, the strain at the bolt–slurry interface changes from a negative index of low strain to a high-strain “S” curve at the end along the bond length. The peak value of slurry–soil interface strain exhibits a transition from the front part of bond length to the middle and back parts of bond length. The mechanical operating mechanism between bolt and slurry is divided into three simplified progressive structural force models, namely “1,” “T,” and “Y.” Finally, the calculation formulas of the average pull-out force of the WTCS are provided.

KEYWORDS:

• Anchor performance
• earthen sites
• interface strain monitoring
• structural stress models
• wooden tension anchor bolt (WTB)
• wooden tension–compression composite anchor bolt (WTCB)

Acknowledgments

The authors’ special thanks go to the editor and two anonymous referees, whose valuable comments led to substantial improvement of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (Grant No. 41562015 and No. 52068050), and Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China (2017IRT17-51)). This work was also supported by the Lanzhou University of Technology’s Support Program for Hongliu Outstanding Young Talents.