What are the main types of soil anchors and what are the scope of application of soil anchors

01 Full-length bonded anchor.

The bolt hole is filled with an anchor rod of adhesive material over the full length of the hole.

02 Prestressing.

Anchor: A bolt to which prestresses are applied.

03 Friction bolt: the friction between the anchor body and the hole wall.

Anchor rods that act as anchors.

04 Mortar anchor: cement mortar.

Fast-hardening cement mortar is a bonded anchor with anchoring agent.

05 Cement medicine roll anchor: a bonded anchor with cement medicine roll as the anchoring agent.

06 Resin anchor: Adhesive anchor with resin as anchoring agent.

07 Self-drilling anchor: The bolt itself has the function of drilling pipe, which combines hole-making, grouting and anchoring, also known as self-propelled anchor.

08 Seam pipe anchor: The thin-walled steel pipe with longitudinal openings is forcibly pushed into a borehole smaller than its outer diameter, and the anchor rod is anchored by the resistance of the steel pipe to the radial pressure of the hole wall.

09 Flower tube grouting anchor: a mortar anchor that is inserted into the rod body with a steel pipe arranged with a certain number of small holes in the pipe wall as the rod body, and then grouting the bolt hole through the small hole in the cavity of the rod body.

10. Expansion anchor: the special-shaped cavity rod processed with thin-walled steel pipe is sent into a slightly larger borehole, and the anchor rod that plays an anchoring role by injecting water into the cavity of the rod at high pressure, so that the rod expands and produces friction resistance to the hole wall.

11. Permanent anchor: Consistent with the service life of the main project, it can maintain stable performance and quality standards during the effective operation period of the project, or has the conditions for maintenance and replacement, and can play a sustainable role.

12. Temporary anchor: It does not meet the standard of the same service life of the main project, and is only required to be under construction.

The anchor rod that plays a role during or at a specific stage is generally not considered under the normal operating conditions of the project.

13. System anchor: according to the overall stability requirements of rock (soil), the anchor is arranged according to a certain spacing and a certain law on the entire excavation surface.

14 random anchor: in order to prevent the rock (soil) body from collapsing or sliding, the anchor is laid locally.

The principle of soil anchor is a kind of lever. Now there are three or four general explanations for the mechanism of action of the bolt.

This is the rock formation bolt:

Principle of bolt support: 1. Suspension, this theory believes that the weaker rock layer is suspended on the upper stable rock layer to enhance the stability of the weaker rock layer. 2. The effect of composite beams, this theory believes that on the one hand, the anchoring force of the anchor increases the contact pressure of each rock layer to avoid the phenomenon of separation of each rock layer, and on the other hand, it increases the shear strength of the rock layer and prevents the horizontal dislocation between the rock layers.

3. Combined arch theory, which believes that installing a prestressed anchor rod on the elastomer can form a conical compression zone with the anchor head and the fastening end as the apex, and form an extrusion reinforced arch. 4. The theory of maximum horizontal stress, this theory believes that the horizontal stress of the mine rock layer is usually greater than the vertical stress, the horizontal stress has obvious directionality, and the maximum horizontal stress is generally times of the minimum horizontal stress, so the bolt anchor plays the role of restraining the separation and inhibiting the expansion of the rock layer.

The mechanism of action of soil anchors can also be explained similarly, but there is the effect of soil reinforcement (the role of grouting, reinforcement, etc.), and the relevant explanations in foundation treatment can also be applied.

The soil anchor is generally composed of three parts: the anchor head, the free section and the anchor section, in which the anchor section uses cement slurry or cement mortar to bond the rod body (prestressed tendon) with the soil body to form the anchor solid of the anchor rod.

According to the soil type, engineering characteristics and use requirements, the solid structure of soil anchor can be designed as cylindrical type, end enlarged head type or continuous spherical type.

Anchor classification: anchored in sandy soil, hard clay layer and requiring high bearing capacity, it is advisable to use the end of the enlarged head anchor solid; Anchors anchored in silt and silty soil layers and require high bearing capacity should be anchored with continuous spherical anchor solids.

1. It can be applied in general clay and sandy soil areas, and soft soil and silty soil areas should be applied after testing.

2. When the groundwater pressure is large, the high-pressure water injection drill pipe should be used to drill holes, and some measures should be taken to prevent water and sand gushing.

3. The use of pile top ring beam as the anchor waist beam can save money.

4. Cast-in-place piles, H-shaped steel piles, underground diaphragm walls and other retaining structures can be supported by anchor ties.

The characteristics of soil anchor construction are:1. The use of anchor Rachel is more convenient than supporting and excavating in the pit.

2. The anchor rod should have a certain coverage depth and pull-out resistance.

3. The displacement of the prestressed anchor rod on the retaining pile and wall should be small.

4. For the pressurized water and soil layer and gravel layer, the drilling rig that uses high-pressure water injection drill pipe and diamond drill pipe.

5. The length of the anchorage section should be determined by calculating and adding the degree of safety.

6. The stress loss of adjacent anchors after tension is large, and the tensile stress should be adjusted again. The general stress loss and timeliness loss are not too large.

7. The actual pull-out strength of the bolt should be determined after the test.

The length or depth of the anchor cable or bolt is insufficient, the strength of the concrete does not reach the design strength, and the grouting is not full.

Soil anchors can be divided into: 1. Ordinary grouting anchors; 2. a pre-compressed anchor; 3. a prestressed anchor; 4. Reaming anchors. Soil anchor is a kind of reinforcement, steel rope and grouting body in the borehole that extends into the stabilized soil at the end, and its role is as a lever.

1. First of all, the project should be retested, and the staff should carry out a second test on the on-site slag and reinforce the control pile.

2. Raw materials need to be prepared, cement, stones, sand, etc., it is best to purchase them in the local building materials market, and then transport them by trucks, so that such as Biji can save a lot of manpower and material resources.

3. The ratio of concrete needs to be adjusted, which is a very strict work, and the ratio of each material must be carefully calculated, and it can be mixed only after obtaining the consent of the chief engineer.

4. It is necessary to do a sampling inspection, and make two sets of samples each time to ensure that there is no problem with the compressive strength of concrete.

5. In the production of concrete, the first thing to do is to deal with the foundation, first to clean up the dust and impurities on the ground, and then drain the water. Secondly, workers should prepare construction machinery, and before pouring, they should apply a layer of isolation glue on the template to avoid cement sticking to the formwork, and it will be difficult to demould at that time. Finally, Huihan should evenly spread the cement and use special tools to level the ground to avoid potholes.

6. The curing of concrete, the later maintenance of concrete is very important, after the concrete is poured, it is necessary to wait for 8 hours, 7 days, and a maximum of 21 days, depending on the local climate and environmental temperature.

1. Fully bonded anchor: fill the entire hole with adhesive.

2. Prestressed anchor cable: a kind of anchor cable with prestress.

3. Friction anchor: an anchor that uses the friction between the anchor rod and the cave wall for anchoring.

4. Mortar anchor: cement mortar and fast-hardening cement mortar are used as anchoring materials, and cement mortar is used as anchoring materials.

5. Film: cementing material with cement film as a fixing material.

6. Resin anchor: a cementing material with resin as the base material.

The above is what I told you about the basic types of soil anchors used for foundations, if you don't know much about this, you can refer to the above content to learn.

01 Full-length bonded bolts: Bolt holes are filled with adhesive material.

02 Prestressed anchor: The anchor rod with prestressed appliance.

03 Friction anchor: an anchor rod that relies on the friction between the anchor body and the hole wall to anchor the anchor.

04 Mortar anchor: Bonded anchor with cement mortar and fast-hardening cement mortar as anchoring agent.

05 Cement medicine roll anchor: the cement medicine roll is used as the anchoring agent of the bonded anchor.

06 Resin anchor: Adhesive anchor with resin as anchoring agent.

07 Self-drilling anchor: The bolt itself has the function of drilling drill pipe, integrating drilling, grouting and anchoring, also known as self-propelled anchor.

08 Seam Tubular Anchor: A thin-walled steel pipe with a longitudinal joint is forcibly pushed into a hole smaller than its outer diameter, and an anchor rod that relies on the resistance of the steel pipe to the radial pressure of the hole wall.

09 Flower tube grouting anchor: After inserting the steel pipe with a certain number of holes in the pipe wall into the borehole, the mortar anchor rod is grouting into the anchor hole through the hole in the cavity of the rod body.

10. Water expansion anchor: The special-shaped cavity anchor made of thin-walled steel pipe is fed into a slightly larger hole. By applying high-pressure water injection sensitivity into the cavity of the rod, the rod expands and creates frictional resistance on the hole wall.

11. Permanent anchor: an anchor that is consistent with the service life of the main project, can maintain stable performance and quality standards during the effective operation of the project, or has maintenance and replacement conditions, and can play a sustainable cavity lifting role.

12. Temporary anchorage: the anchorage that cannot meet the same life standard of the main project and only needs to play a role during construction or at a specific stage. Generally, its function is not considered under the normal working conditions of the project.

13. System anchor: according to the overall stability requirements of rock (soil), the anchor is arranged according to a certain spacing and a certain law on the entire excavation surface.

14. Random anchors: In order to prevent the rock (soil) from collapsing or sliding, the anchors are locally laid.

What is the scope of application of the early age rod of soil anchor?

Correct answer: 1) It is suitable for large-scale deep foundation pits, with a long construction period, adjacent buildings, and no support is allowed, and adjacent foundations are not allowed to be used when there is a blind sinking displacement under the land.

2) It is suitable for excavating larger and deeper foundation pits in harder soil layers or broken rocks, and is used when there are buildings nearby to ensure the stability of the slope.

Prestressed soil anchors are widely used in deep foundation pit support, slope reinforcement, landslide control, pool anti-floating, retaining wall anchorage and structural anti-overturning in China. The soil layer consists of an anchor head, a tie rod and an anchor body. According to the different sliding surfaces, the soil anchor is divided into anchored and non-anchored sections.

Its bearing capacity is affected by the strength of the tie rod, the binding force between the tie rod and the anchor body, and the friction between the anchor body and the hole wall. The soil anchor is a kind of tie rod, one end is connected with the retaining pile, retaining wall or engineering structure, and the other end is anchored in the soil layer to maintain the stability of the structure and the supported Liangshou soil layer. Soil anchors can simplify the basic structure, make the structure light and reasonable, and have the advantages of taking up less space, shortening the construction period, and reducing costs.

It can be used as a temporary support for deep excavation of foundation pit wall, and can also be used as a permanent foundation for engineering structures. It is used in the enclosure structure of the foundation pit of the house, which can effectively prevent the collapse, displacement and settlement of the surrounding soil layer. In the case that the lateral support of the foundation pit wall can not be adopted, the soil anchor technology is more effective.

The construction process of soil anchor includes hole formation, placement of tie rod, grouting and tension locking.

Soil anchors are referred to as soil anchors. It is to drill holes in the unexcavated soil layer of deep foundation soil wall, and after reaching a certain depth, put steel bars, steel pipes, steel wire bundles, steel strands and other materials into the holes, and pour mud skin resistance or chemical slurry to combine with the soil layer to become an anchor with strong tensile strength. The end of the bolt is connected with the wall protection pile to prevent the soil wall from collapsing or landslide.

Since there is no support in the pit, the construction conditions are better.

Soil anchors are increasingly widely used in deep foundation pit support, slope reinforcement, landslide remediation, pool anti-floating, retaining wall anchoring and structural anti-overturning projects in China. Grinding.

According to the sliding surface, the soil anchor rod is divided into anchor blind mu decay section and non-anchor section. Its bearing capacity is affected by factors such as the strength of the tie rod, the grip between the tie rod and the anchor solid, and the friction between the anchor solid and the hole wall.