Fig 1.
Schematic diagram of the anchorage structure for a grouting anchor: 1-nuts, 2-anchor tray, 3-exhaust pipe, 4-grouting pipe, 5-sealing plug, 6-anchor, 7-grouting body, and 8-surrounding rock.
Fig 2.
Schematic diagram of the proposed high-pressure pre-tightening resin anchor with a compressed grouting body: 1-nuts, 2-anchor tray, 3-exhaust pipe, 4-grouting pipe, 5-sealing plug, 6-anchor, 7-PVC casing, 8-grouting body, 9-resin body, and 10-surrounding rock.
Fig 3.
Construction technology diagram for the high-pressure pre-tightening resin anchor with a compressed grouting body: 1-anchor, 2-nut, 3-tray, 4-exhaust pipe, 5-grouting pipe, 6-PVC casing, 7-sealing plug, and 8-resin capsules.
Table 1.
Compressive strengths and elastic moduli of the specimens.
Fig 4.
(a) Physical model of an anchor pile. (b) Loading devices.
Fig 5.
Axial strain in the grouting body of the proposed anchor under different pre-tightening forces.
Note: The origin of the coordinate system in Fig 5 is located at the drilling aperture of the anchor.
Fig 6.
Axial strain in the grouting body of the conventional anchor under different pre-tightening forces.
Note: The origin of the coordinate system in Fig 6 is located at the drilling aperture of the anchor.
Fig 7.
Comparison of the axial strains in the grouting bodies of the proposed anchor and the conventional anchor.
1: conventional anchor, 120 kN; 2: conventional anchor, 80 kN; 3: conventional anchor, 40 kN; 4: proposed anchor, 120 kN; 5: proposed anchor, 80 kN; and 6: proposed anchor, 40 kN.
Fig 8.
Axial strains in the grouting bodies of high-pressure pre-tightening resin anchors with compressed grouting bodies in surrounding rock with different elastic moduli.
1: pull-out force of 120 kN and C20 surrounding rock; 2: pull-out force of 120 kN and C30 surrounding rock; 3: pull-out force of 120 kN and C40 surrounding rock; 4: pull-out force of 60 kN and C20 surrounding rock; 5: pull-out force of 60 kN and C30 surrounding rock; and 6: pull-out force of 60 kN and C40 surrounding rock.
Fig 9.
Axial strains in the grouting bodies of conventional tensile-type anchors in surrounding rock with different elastic moduli.
1: pull-out force of 120 kN and C20 surrounding rock; 2: pull-out force of 120 kN and C30 surrounding rock; 3: pull-out force of 120 kN and C40 surrounding rock; 4: pull-out force of 60 kN and C20 surrounding rock; 5: pull-out force of 60 kN and C30 surrounding rock; and 6: pull-out force of 60 kN and C40 surrounding rock.
Fig 10.
Actual displacement at the pull-out end of the anchor.
1: conventional anchor, C20; 2: conventional anchor, C30; 3: conventional anchor, C40; 4: proposed anchor, C20; 5: proposed anchor, C30; and 6: proposed anchor, C40.