What Are Suture Anchors?

Anchor rod is the most basic component of roadway support in contemporary coal mines. He strengthens the surrounding rock of the roadway together, so that the surrounding rock itself supports itself. Now anchor bolts are not only used in mines, but also in engineering technology, for the main reinforcement of slopes, tunnels and dams. Anchor rod is a tensile member deep into the ground. One end is connected to the engineering structure and the other end is deep into the ground. The entire anchor rod is divided into a free section and an anchoring section. The free section refers to transmitting the tensile force at the head of the anchor rod to the anchor. Area, its function is to pre-stress the anchor.

There are several factors that make up an anchor:

A rod with higher tensile strength than rock and soil.

One end of the rod body can be in close contact with the rock and soil body to form friction (or adhesion) resistance.

The other end of the rod located outside the rock and soil can form radial resistance to the rock and soil.

Principle of action: Anchor rod is a tensile member that penetrates deep into the ground. One end is connected to the engineering structure and the other end penetrates into the ground. The entire anchor is divided into a free section and an anchoring section. To the area of the anchor, its function is to apply to the anchor

Anchor rod is a member structure reinforced by rock and soil.

Through the longitudinal tensile action of the anchor rod body, the disadvantage that the tensile capacity of the rock and soil body is far lower than the compressive capacity is overcome.

On the surface, it restricts the detachment of rock and soil from the original body.

Macroscopically, it increases the cohesion of rock and soil.

From a mechanical point of view, the cohesion C and

Since 1912,

(1) Wooden anchor. There are two types of wood anchors used in China, namely ordinary wood anchors and compressed wood anchors. Listed below are several anchors

(2) Reinforced or wire rope mortar anchors. Cement mortar is used as the binder between anchor rod and surrounding rock.

(3) Inverted wedge metal anchor. This anchor was once one of the most widely used anchor forms. Because it is simple to process, easy to install, and has a certain anchoring force, this anchor rod is still used in a certain range.

(4) Pipe seam anchor. It is a full-length friction anchor bolt. This anchor has the characteristics of simple installation, reliable anchoring, large initial anchoring force, and long-term anchoring force increasing with the movement of surrounding rocks.

(5) Resin anchor. The cost of using resin as the anchor of the anchor is high.

(6) Fast hard expansion cement anchor. Use ordinary Portland cement or

Anchor pipe seam anchor

Pipe-slot anchor is a new type of full-length anchor that actively reinforces surrounding rock. Its three-dimensional part is a high-strength steel pipe with a longitudinal slit. When installed in a hole smaller than the pipe diameter, it can be immediately The radial pressure is applied to the hole wall and the friction force to prevent the surrounding rock from sliding down, and the supporting force of the anchor tray pallet is added, so that the surrounding rock is in a three-way stress state. In the case of blasting vibration surrounding rock anchoring, the anchoring force has increased significantly in the later period. When the surrounding rock is significantly displaced, the anchor rod does not lose its supporting resistance. It has better characteristics than the expanded shell anchor rod.

Main performance and specifications of pipe joint anchor

1. Main technical performance

(1) Initial anchoring force: 3 ~ 7 tons;

(2) Pull-out load of pipe ring: 8 ~ 10 tons;

(3) Anti-breaking capacity of anchor pipe: 12 ~ 13 tons;

(4) The corrosion resistance is 20-30% higher than A3 steel, which is conducive to long-term use.

2.Specifications

(1) Outside diameter (mm): 30, 33, 40, 43 (± 0.5)

(2) Length (mm): 1200, 1500, 1800, 2000, 2500

(Can also be produced according to customer's requirements);

(3) Material: 16Mn, 20 Mnsi;

The use of pipe seam bolts is relatively rare.

Anchor Spin Anchor

1 Overview of spin anchors Spin anchors are a type of spiral anchor that, if used reasonably, will become top-level anchors.

Spiral anchor is one of the soft soil layer anchors developed in the early last century, because this kind of anchor construction is simple and fast and widely used in some field engineering or auxiliary soil anchoring. In the long-term research and practice, Professor Hui Xingtian of Xi'an University of Science and Technology thoroughly analyzed the traditional spiral anchor and invented a new type of spiral anchor spin anchor in 1999. Spin anchors discard the large anchor leaf structure of traditional spiral anchors, use hollow continuous small spiral wire structures, and use different construction techniques to make fundamental changes in the application of spin anchors. Thus, an all-round system with a series of functions is derived. The following is a brief description of the various types of spin anchors.

Self-tapping into the anchor rod Self-tapping into the borehole can achieve 70KN anchoring force without using an anchoring agent.

Innovation: Full-length anchors without anchors.

Advantages: low cost and fast construction speed.

Disadvantages: Installation requires precise drilling and proper coordination of various parameters. It is difficult to meet the requirements during construction.

Self-tapping and squeezing into the anchor rod No need to drill holes in the soil layer to directly squeeze into the anchoring force of 20KN / m.

Innovation: full-length anchor bolts without drilling or grouting.

Advantages: Extruded and strengthened soil structure greatly improves soil bearing capacity, fast construction speed and timely anchoring;

Disadvantages: The drilling rig has large torque requirements, limited adaptability, and small unit anchoring forces in individual cases.

Spin grouting anchor After the installation in the borehole, the grouting with the spin anchor becomes a spin grouting anchor with initial anchor force.

Innovation: grouting anchor with initial anchoring force and full-length anchoring.

Advantages: It has a certain initial anchoring force and is suitable for various soft rock and soil.

Disadvantages: the grouting process takes time, the construction environment is poor, and the speed is limited.

Spin resin anchor Spin resin anchor stirs the resin medicine roll into a spin resin anchor with initial anchor force while being installed in the drilling hole.

Innovation: Pre-stressed resin anchors are applied immediately after the stirring of the medicine roll.

Advantages: reliable anchoring and wide adaptability

Disadvantage: Anchor rod installation requires special drilling tools

Self-drilling and self-anchoring anchor Put the drill rod in the hollow of the spin anchor to complete the installation of the drill hole once.

Innovative point: self-drilling anchor rods with one-time installation and initial anchoring force.

Advantages: It has a certain initial anchoring force, fast installation, and is suitable for any rock and soil layer.

Disadvantage: Installation requires special drilling tools.

Spin-up shotcrete anchor Drill and install the anchor while spraying shot in the soil to complete the anchoring force of 35KN / m.

Innovative point: soil bolts for drilling hole installation and grouting.

Advantages: suitable for loose rock soil.

Disadvantages: Can not be used for loose bodies in rock fragmentation zones.

2. Schematic illustration of the all-around spin anchor

Self-drilling, spinning, self-anchoring-adapt to any formation.

Grouting, shotcrete, rotary grout-effective in any situation

Spin anchor: ordinary anchor + self-drilling anchor + grouting anchor + special anchor

3 .Spin anchor system

Self-tapping

1. Direct self-tapping-spinningSelf-tapping squeeze and screw into the anchor with a drill bit, and use a drill to directly drive the anchor into the soil. The anchor rod squeezes the soil around the rod body during the screwing process, so that the parameters of the soil body close to the rod body are strengthened.

Self-tapping squeeze screw anchor is different from self-drilling anchor. The anchoring of self-drilling anchor depends on post-anchoring grouting. It is difficult to achieve saturated grouting for upward holes, and the anchoring reliability is poor. The spin anchor itself forms an anchoring force and installation is complete. Any angle can guarantee the same anchoring force.

Application conditions of self-tapping squeeze screw anchor: collapsible loess, silt, loose rock and soil.

2. Self-tapping and self-tapping in holesSelf-tapping and pre-drilling anchor rods are drilled in pre-drilled holes. The anchor rod is driven by a drilling rig. During rotation, the anchor wire is engraved into the wall of the bore hole for anchoring .

Self-drilling into anchor

The drill rod is placed in the anchor body, and the anchor rod is installed while drilling. Drilling and installation is completed at one time, which is conducive to ensuring anchoring reliability and fast construction speed.

Applicable conditions: Any formation, especially suitable for soft and broken rock and soil.

Spin grouting anchor

Drill holes in advance, screw the spin anchor into the borehole, and use the hollow grouting of the rod body after installation. Part of the slurry fills the spinning space along the spinning thread, and part of the slurry penetrates into the rock mass to strengthen the rock layer, so that the rock mass is anchored at the same time The body gets reinforced for grouting.

Applicable conditions: Any stratum, especially suitable for spin-casting bolts in soft and broken rock and soil.

Anchor rods are used for grouting in complex soil layers, and grouting is completed in this way.

Spin resin anchor

A resin anchor is placed at the front end of the spin anchor. During the installation of the spin anchor, the resin is pressurized and stirred to make the resin anchor fill the spinner. The anchor and the spinner together play an anchoring role ^[3] .