Shear Characteristics of Cuneiform Reaming Anchorage Bolts in Coal Mine Roadways

Liu, Shaowei; Fu, Mengxiong; Jia, Housheng; Li, Wenbin

doi:10.1007/s00603-018-1670-3

Cited by 20 publications

(7 citation statements)

References 9 publications

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“…Therefore, their effect is equivalent to a solid circular beam model, as shown in Figure 15 d. In the range of joint-plane shear action, both a bending moment and shear force exist in the pipe–cable bearing whole section; therefore, deformation of this beam occurs as transverse bending. According to material mechanics, the maximum shear stress on the pipe–cable bearing whole cross-section on the joint plane ( Figure 15 d) is expressed as follows [ 44 ]:

where

is the maximum shear stress on the pipe–cable bearing whole section; F 2 is the shear resistance provided by the pipe–cable bearing whole; d is the diameter of the pipe–cable bearing whole cross-section along the neutral axis z ; I z denotes the moment of inertia of the pipe–cable bearing whole cross-section applied to the neutral axis z ,

;

denotes the static moment of the pipe–cable bearing whole cross-section applied to the neutral axis z ,

; and A is the cross-sectional area of the pipe–cable bearing whole. Assuming that the shear strength of the Q-CFSD is lower than that of the cable bolt, the steel pipe will break before the cable bolt.…”

Section: Discussionmentioning

confidence: 99%

“…In the range of joint-plane shear action, both a bending moment and shear force exist in the pipe-cable bearing whole section; therefore, deformation of this beam occurs as transverse bending. According to material mechanics, the maximum shear stress on the pipe-cable bearing whole cross-section on the joint plane (Figure 15d) is expressed as follows [44]:…”

Section: Discussionmentioning

confidence: 99%

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Strengthening Device for Improving Shear Performance of Anchor Cable in Rock Support

Feng,

Liu,

Jia

et al. 2023

Materials

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Many designs of anchor cables are currently in use for rock support in civil and mining operations. Because of the exposed surface and weak shear performance of the cable bolt’s free section (CBFS) in end-anchored structures, breaking failure frequently occurs. Numerical simulations and laboratory experiments were performed in this study to develop measures to improve CBFS resistance to shear failure. Analysis of shear characteristics of the CBFS showed that higher axial tension weakens the cable bolt’s shear resistance, and that shear damage on the cable surface and uneven distribution of shear stress aggravate CBFS tensile–shear failure. A high-strength steel pipe is proposed to protect the shear cable bolt, and the preliminary design of a CBFS-strengthening device (CFSD) is presented. Numerical simulation revealed that the CFSD effectively improved CBFS shear resistance and provided protection from harmful shear damage. The optimal performance of a Q-type (slotted steel pipe) CFSD was confirmed. The mechanism of improvement of the cable’s shear resistance to surrounding rock by employing the CFSD was analyzed. Double-shear tests were carried out on a bare cable bolt and a cable bolt with a Q-CFSD. The results revealed that the CFSD increased the peak shear force on the joint plane, cable peak axial force, and ultimate shear displacement by 31%, 18%, and 11%, respectively. The proposed device is effective in improving the shear performance of end-anchored cable bolts and enhancing surrounding rock stability.

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where

;

denotes the static moment of the pipe–cable bearing whole cross-section applied to the neutral axis z ,

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Strengthening Device for Improving Shear Performance of Anchor Cable in Rock Support

Feng,

Liu,

Jia

et al. 2023

Materials

Self Cite

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“…Bai et al (2019) studied the influence of hard rock band on top-coal breaking in longwall mining by physical modeling. Liu et al (2019b) presented the shear characteristics of rock bolting with a cuneiform reaming anchorage. It is shown that this type of rock bolting can provide high shear resistance against shear slip along joint planes when the cuneiform grout is located near to the weak plane.…”

Section: The Special Issuementioning

confidence: 99%

Introduction to the Special Issue “Rock Mechanics Advances in China Coal Mining”

Zhang

Barla

2019

Rock Mech Rock Eng

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“…Parametric studies were conducted to assess the effects of the end plate on the geological conditions with different rock mass qualities, in situ stresses, shearing stiffness at the bolt-grout interface, and stiffnesses of the end plate. Liu et al , He et al, Zhi et al, Fu et al, and Jia et al designed a device which guarantees the bolt in the center of the borehole and increases the mixing uniformity of the anchorage agent in the soft rock roadway because of insufficient support strength and high failure rate of bolt support. The application of these devices can increase the bonding force between anchorage agent and surrounding rock interface, so as to increase the shear capacity between anchorage agent and surrounding rock interface, and then to increase the stability of anchorage system, and reduce the occurrence of bolt failure.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Resin Anchoring with Reaming Bottom and Filling in Soft Rock

et al. 2023

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This paper deals with the problem of the slippage failure of bolts in supporting soft rock, and the anchoring system being pulled out when conventional anchoring methods are used for bolts. This situation seriously threatens the safety of personnel and efficiency of work at the supporting soft rock. The main goal of this paper is to develop methods that will take full advantage of the potentially great supporting force that can be provided by bolts installed in soft rock. The study discusses the resin anchoring technique with reaming bottom and filling and proposes that replacing soft rock with high strength hard rock is an effective method to improve the anchoring force that prevents slip failure. The results of a comparative analysis of the different maximum diameters of reaming and the anchorage performance of the method using laboratory testing, numerical simulation, mechanics analysis, and field test are described. The results show that when the reaming diameter is less than five times that of the borehole, the anchorage force increases significantly. When the reaming diameter is more than five times that of the borehole, the increasing degree of anchoring force decreases obviously and the trend is gentle. The anchoring force of five times resin anchoring with reaming bottom and filling is 2.8 times that of conventional anchorage. The resin anchoring technique with reaming bottom and filling guarantees that bolts installed in soft rock will provide high supporting forces.

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Shear Characteristics of Cuneiform Reaming Anchorage Bolts in Coal Mine Roadways

Cited by 20 publications

References 9 publications

Strengthening Device for Improving Shear Performance of Anchor Cable in Rock Support

Strengthening Device for Improving Shear Performance of Anchor Cable in Rock Support

Introduction to the Special Issue “Rock Mechanics Advances in China Coal Mining”

Experimental Study on Resin Anchoring with Reaming Bottom and Filling in Soft Rock

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