Distributed bottom expansion anchor device and construction method thereof

Abstract

The present invention relates to a distributed bottom-enlarged anchor device and a construction method thereof, wherein the anchor device comprises a bottom-enlarged rod body and a common rod body that are fixedly connected; the bottom-enlarged rod body comprises a steel pipe and an embedded grouting pipe arranged inside the steel pipe, a blade base is arranged at the bottom end of the bottom-enlarged rod body, a rotating fastener and a bottom-enlarged blade are installed on the blade base, and a connecting end plate is arranged at the top end of the bottom-enlarged rod body; the common rod body comprises a steel pipe and an embedded grouting pipe, and a connecting end plate is arranged at the bottom and top end of the common rod body, respectively. The anchor rod of the present invention has a higher pull-out bearing capacity, which can significantly reduce the number of engineering anchor rods and save materials. In addition, the bottom-enlarged anchor rod device protects the wall by itself, does not need to use mud, and is more environmentally friendly. It can be widely used in soft clay or loose sand layers and other formations prone to collapse, which greatly expands the scope of use of anchor rods.

Description

Technical Field

[0001] The invention relates to the field of anti-floating of underground buildings, and more specifically to a distributed bottom expansion anchor rod device and a construction method thereof. Background Art

[0002] Anti-floating anchor rods are a type of anti-floating measure for underground structures in construction projects. They are widely used to solve the anti-floating problem of underground structures because of their simple construction and low cost. The entire cross-section of an ordinary anchor rod is one diameter. In rock or hard plastic strata, the anchor rod can provide a large pull-out resistance. However, in soft plastic or plastic soil layers, the pull-out resistance provided by ordinary anchor rods is limited, and it is often necessary to increase the length of the anchor rod to obtain the required pull-out bearing capacity. In addition, ordinary anchor rods must be drilled first, and when encountering strata prone to collapse, mud wall protection or casing follow-up construction measures are often required, which can easily cause greater environmental pollution or complex procedures and high costs. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a distributed bottom expansion anchor device and a construction method thereof, wherein the anchor has a higher pull-out bearing capacity, can significantly reduce the number of engineering anchors, and save materials.

[0004] The technical solution adopted by the present invention to solve its technical problems is: constructing a distributed bottom expansion anchor rod device, including a bottom expansion rod body and a common rod body fixedly connected; the bottom expansion rod body includes a steel pipe and an embedded grouting pipe arranged inside the steel pipe, a blade base is arranged at the bottom end of the bottom expansion rod body, a rotating fastener and a bottom expansion blade are installed on the blade base, and a connecting end plate is arranged at the top end of the bottom expansion rod body; the common rod body includes a steel pipe and an embedded grouting pipe, and the bottom and top ends of the common rod body are respectively provided with connecting end plates.

[0005] According to the above solution, a sealing guide cap is provided at the end of the first section of the expanded bottom rod body.

[0006] According to the above solution, bolt holes are provided on the connecting end plate.

[0007] According to the above scheme, the embedded grouting pipe is injected with cement slurry.

[0008] According to the above solution, the steel pipe is provided with grouting holes.

[0009] The present invention also provides a distributed bottom expansion anchor device and a construction method thereof, comprising the following steps:

[0010] Step 1: Calculate the required bottom expansion range according to the site geological conditions and the pull-out bearing capacity requirements of a single anchor rod, and select and determine the length of the bottom expansion rod body and the ordinary rod body;

[0011] Step 2: prefabricate the rod structure of the expanded bottom rod in the factory, and configure the expanded bottom blades and blade base;

[0012] Step 3: Use a pre-drilled hole or static pressure construction method, install a sealing guide cap at the bottom end of the first section of the bottom expansion rod body, put the anchor rod body into the drill hole or statically press the first section of the anchor rod body into the formation;

[0013] Step 4: Connect the second section of the bottom expansion rod body by connecting the end plates, and continue to put it into the borehole or static pressure rod body into the formation;

[0014] Step 5: Repeat steps 3 and 4 until all the bottom expansion rods and common rods are pressed into the formation;

[0015] Step 6: Inject cement slurry into the embedded grouting pipe. After the cement slurry fills the first section of the bottom expansion rod, high pressure is formed. The high pressure drives the rotating fasteners on the blade base, so that the bottom expansion blades slowly open and embed into the surrounding soil layer to form a bottom expansion section. After the blades of the first section of the bottom expansion rod are fully opened, high-pressure cement slurry is injected into the second and third sections of the rod in turn. Under the action of the high-pressure slurry, the bottom expansion blades of each bottom expansion section are slowly opened to the final normal working state, forming a multi-section distributed bottom expansion structure.

[0016] Step 7: After the grouting of all the bottom-enlarged rods is completed, the cement slurry continues to flow upward into the ordinary rods; after the cement slurry fills the hollow structure of all the rods, the grouting is stabilized for a period of time to ensure the grouting effect.

[0017] The distributed bottom expansion anchor device and the construction method thereof of the present invention have the following beneficial effects:

[0018] 1. The present invention can expand the bottom at different depths in the soil layer according to the site geological conditions and the pull-out bearing capacity requirements of a single anchor rod, increase the cross-sectional area of ​​the anchor rod, change the transmission mode of soil friction resistance, significantly improve the pull-out bearing capacity, reduce the number of engineering anchor rods, and save materials.

[0019] 2. The distributed bottom anchor device can be constructed by static pressure or hammering. The bottom anchor device protects the wall by itself and does not require the use of mud, which is more environmentally friendly. It can be widely used in soft clay or loose sand layers and other strata prone to collapse, greatly expanding the scope of use of anchors. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0021] Figure 1 It is a structural schematic diagram of the expanded bottom rod body;

[0022] Figure 2 It is a schematic diagram of the structure of a common rod;

[0023] Figure 3 It is a schematic diagram of a distributed bottom expansion anchor device for use in harder formations;

[0024] Figure 4 yes Figure 3 Schematic diagram of the working state of the distributed bottom expansion anchor device;

[0025] Figure 5 yes Figure 3 Schematic diagram of the first section of the expanded bottom rod body;

[0026] Figure 6 yes Figure 5 AA section view in;

[0027] Figure 7 yes Figure 6 Schematic diagram of the bottom-enlarged blade in the retracted state;

[0028] Figure 8 It is a schematic diagram of a distributed bottom expansion anchor device for softer formations;

[0029] Fig. 9 yes Figure 8 Schematic diagram of the working state of the distributed bottom expansion anchor device;

[0030] Fig.10 yes Figure 8 Schematic diagram of the first section of the expanded bottom rod body;

[0031] Fig.11 yes Fig.10 BB section view in;

[0032] Fig.12 yes Fig.11 Schematic diagram of the expanded bottom blade in the retracted state. DETAILED DESCRIPTION

[0033] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0034] like Figure 1-12 As shown, the distributed bottom-enlarged anchor rod device of the present invention is divided into a bottom-enlarged rod body 1 and a common rod body 2, and the bottom-enlarged rod body 1 and the common rod body 2 are spliced ​​together.

[0035] The bottom expansion rod body 1 includes a steel pipe 3 and an embedded grouting pipe 4. A blade base 5 is provided at the bottom end of the bottom expansion rod body, and a rotating fastener 6 and a bottom expansion blade 7 are installed on the blade base 5. The bottom expansion blade 7 is a fan blade type or an umbrella blade type. A connecting end plate 8 is provided at the top end of the bottom expansion rod body, and a plurality of bolt holes 9 are provided on the connecting end plate 8. A sealing guide cap 10 is provided at the end of the first section of the bottom expansion rod body 1.

[0036] The common rod body 2 comprises a steel pipe 3 and an embedded grouting pipe 4. The bottom and top ends of the common rod body 2 are respectively provided with connecting end plates 8.

[0037] The bottom expansion rod body 1 and the common rod body 2 are hollow structures. After the hollow rod body is filled with cement slurry, the strength and rigidity of the anchor rod body itself can be improved. When the anchor device is constructed to the designed elevation, high-pressure cement slurry is injected into the hollow structure anchor device. The high-pressure cement slurry drives the bottom expansion blade 7 on the blade base 5 to slowly open to the final working shape to form a bottom expansion section.

[0038] According to different stratum conditions, different shapes of bottom expansion blades 7 and construction methods are selected. When the stratum is hard, fan-shaped bottom expansion blades 7 and pre-hole construction methods can be selected. When the stratum is soft, umbrella-shaped bottom expansion blades 7 can be selected and static pressure construction methods are preferred.

[0039] Preferably, the bottom expansion rod body 1 can be provided in a single section or multiple sections according to the burial depth and the soft and hard state of the stratum. When multiple sections are provided, the bottom expansion sections can be distributed in equal or non-equal intervals.

[0040] Preferably, if high-pressure cement slurry is used to force the bottom expansion blades 7 to open and when there is resistance, a power device can be installed on the top of the anchor device so that the rotation of the anchor drives the bottom expansion blades 7 to rotate, physically cutting the soil layer and reducing the resistance when the bottom expansion blades 7 open.

[0041] Preferably, a number of small grouting holes can be appropriately set on the outer wall of the steel pipe 3 of the anchor device. During the grouting and pressure stabilization stage, cement slurry can penetrate into the stratum around the steel pipe 3 through the small holes, increasing the friction resistance between the anchor and the soil and improving the pull-out bearing capacity of the ordinary rod section.

[0042] The bottom expansion blades 7 on the bottom expansion rod body 1 are closely attached to the blade base 5 or the wall of the steel pipe 3 during construction. After the construction is completed, they can be fully opened and embedded in the soil layer under the action of the cement slurry pressure in the middle, increasing the contact area between the anchor rod and the soil layer, changing the transmission mode of the friction resistance of the soil, significantly improving the pull-out bearing capacity, reducing the number of engineering anchor rods, and saving materials.

[0043] The bottom anchor device can be constructed by static pressure or hammering. The bottom anchor device protects the wall by itself and does not require the use of mud, which is more environmentally friendly. It can be widely used in soft clay or loose sand layers and other strata prone to collapse, greatly expanding the scope of use of anchors.

[0044] The bottom anchor device is divided into a bottom anchor body 1 and a common anchor body 2. Both the bottom anchor body 1 and the common anchor body 2 can be manufactured in a factory and simply assembled after being transported to the construction site. The construction speed is fast, the building materials are saved, and it is more green and environmentally friendly.

[0045] The present invention provides a distributed bottom expansion anchor device and a construction method thereof, comprising the following construction steps:

[0046] Step 1: According to the geological conditions of the site and the pull-out bearing capacity requirements of a single anchor rod, calculate the required range of the bottom expansion section and select the optimal combination of the bottom expansion rod body and the ordinary rod body.

[0047] Step 2: Prefabricate the rod structure of the expanded bottom rod in the factory and configure appropriate expanded bottom blades and blade bases.

[0048] Step 3: According to the geological conditions of the site, choose to use the pre-drilling or static pressure construction method. Install a sealing guide cap at the bottom end of the first section of the bottom expansion rod body, put the anchor rod body into the drilled hole or statically press the first section of the anchor rod body into the formation.

[0049] Step 4: Connect the second section of the bottom expansion rod body by connecting the end plates, and continue to put it into the borehole or static pressure rod body into the formation.

[0050] Step 5: Repeat steps 3 and 4 until all the bottom expansion rods and common rods are pressed into the formation.

[0051] Step 6: Inject cement slurry into the embedded grouting pipe. After the cement slurry fills the first section of the bottom expansion rod, high pressure is formed. The high pressure drives the rotating fasteners on the blade base, so that the bottom expansion blades slowly open and embed into the surrounding soil layer to form a bottom expansion section. After the blades of the first section of the bottom expansion rod are opened, high-pressure cement slurry is injected into the second and third sections of the rod in turn. Under the action of the high-pressure slurry, the bottom expansion blades of each bottom expansion section slowly open to the final normal working state, forming a multi-section distributed bottom expansion structure.

[0052] Step 7: After all the bottom expansion rods are grouted, the cement slurry continues to flow upward into the ordinary rods. After the cement slurry fills the hollow structure of all the rods, the grouting is stabilized for a period of time to ensure the grouting effect.

[0053] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A construction method of a distributed bottom expansion anchor device, characterized in that: The distributed bottom expansion anchor device adopted comprises a bottom expansion rod body (1) and a common rod body (2) which are fixedly connected; the bottom expansion rod body (1) comprises a steel pipe (3) and an embedded grouting pipe (4) arranged inside the steel pipe (3); a blade base (5) is arranged at the bottom end of the bottom expansion rod body (1); a rotating fastener (6) and a bottom expansion blade (7) are installed on the blade base (5); a connecting end plate (8) is arranged at the top end of the bottom expansion rod body (1); the common rod body (2) comprises a steel pipe (3) and an embedded grouting pipe (4); a connecting end plate (8) is respectively arranged at the bottom and top ends of the common rod body (2); a sealing guide cap (10) is arranged at the end of the first section of the bottom expansion rod body (1); a bolt hole (9) is arranged on the connecting end plate (8); cement slurry is injected into the embedded grouting pipe (4); and a grouting hole is arranged on the steel pipe (3); The construction method includes the following steps: Step 1: Calculate the required bottom expansion range according to the site geological conditions and the pull-out bearing capacity requirements of a single anchor rod, and select and determine the length of the bottom expansion rod body and the ordinary rod body; Step 2: prefabricate the rod structure of the expanded bottom rod in the factory, and configure the expanded bottom blades and blade base; Step 3: Use a pre-drilled hole or static pressure construction method, install a sealing guide cap at the bottom end of the first section of the bottom expansion rod body, put the anchor rod body into the drill hole or statically press the first section of the anchor rod body into the formation; Step 4: Connect the second section of the bottom expansion rod body by connecting the end plates, and continue to put it into the borehole or static pressure rod body into the formation; Step 5: Repeat steps 3 and 4 until all the bottom expansion rods and common rods are pressed into the formation; Step 6: Inject cement slurry into the embedded grouting pipe. After the cement slurry fills the first section of the bottom expansion rod, high pressure is formed. The high pressure drives the rotating fasteners on the blade base, so that the bottom expansion blades slowly open and embed into the surrounding soil layer to form a bottom expansion section. After the blades of the first section of the bottom expansion rod are fully opened, high-pressure cement slurry is injected into the second and third sections of the rod in turn. Under the action of the high-pressure slurry, the bottom expansion blades of each bottom expansion section are slowly opened to the final normal working state, forming a multi-section distributed bottom expansion structure. Step 7: After the grouting of all the expanded bottom rods is completed, the cement slurry continues to flow upward into the ordinary rods; after the cement slurry fills the hollow structure of all the rods, the grouting is stabilized for a period of time to ensure the grouting effect.

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