Experimental Study on Mechanical Properties and Support of High Strength Prestressed Bolt
High-strength prestressed bolt support is a further optimization development of traditional bolt support technol-ogy.Due to the complex geological characteristics of deep roadway,such as surrounding rock breakage and high stress,more high-strength prestressed bolts are used instead of traditional bolts.In this paper,the mechanical properties of high-strength prestressed anchor bolts are compared and analyzed through theoretical analysis,prestress conversion test,pull out test of left and right rotary anchor bolt and anchorage force test,and the supporting mechanism of new left-handed high-strength pres-tressed anchor bolts is revealed.The results show that:① Theoretical analysis of the action mechanism of the anchor rod in the surrounding rock,elucidating the reinforcement of the prestressed anchor rod on the surrounding rock.② The efficiency of con-verting the torque of rolling wire bolt into preloading force is about 1.7～1.9 times that of equal strength full thread bolt.The mechanical properties of left-handed rolling wire bolts with different diameters are better than those of right-handed full thread bolts.The anchoring force of left-hand threaded steel bolt is greater than that of right-hand threaded steel bolt.③ Analyze the structure of the new left-handed high-strength prestressed bolt,which has the advantages of high prestress,high anchoring force and large effective section.It provides a useful reference for the optimization and innovation of deep roadway surrounding rock support technology.
high strength prestressed anchorroll wire boltfull thread boltsurrounding rock controlmechanical experi-ment
NETL
NSTL
万方数据
维普
