Construction method of ice layer head-expanding self-locking anchor rod

Abstract

The invention belongs to the technical field of buildings, and relates to a construction method of an ice layer head-expanding self-locking anchor rod, which comprises the following steps of: S1, forming a drill hole (8) by using a drill bit, and enabling the drill hole (8) to penetrate through an accumulated snow and freeze thawing layer (6) and then penetrate into a perpetual freezing ice layer (7); s2, an ice layer head-expanding self-locking anchor rod is inserted into the drill hole (8), the ice layer head-expanding self-locking anchor rod comprises an anchor rod body (1) and a head-expanding device (2) arranged at the lower end of the anchor rod body (1), and the head-expanding device (2) is located in the bottom of the drill hole (8); s3, the drill hole (8) is filled with water; and S4, after irrigation water is frozen, a connecting part (1-1) reserved at the top of the anchor rod body (1) penetrates through a reserved hole of a foundation and is connected with the foundation, and construction of the ice layer head-expanding self-locking anchor rod is completed. No cementing material is adopted, pouring and maintenance are not needed, construction is convenient and fast, materials are light and convenient to transport and carry, and on-site zero pollution is achieved.

Description

Technical Field

[0001] This invention belongs to the field of building technology and relates to a method for constructing anchor bolts, and more particularly to a method for constructing a self-locking anchor bolt with an expanded head for ice layers. Background Technology

[0002] In ice-covered regions such as the Arctic and Antarctic, buildings sit atop ice layers, using the ice as a foundation bearing layer, while simultaneously needing to withstand the uplift forces of strong winds. Uplift resistance for such buildings requires techniques such as adding counterweights, installing pull-out piles, or anchor bolts. However, traditional pile or anchor bolt techniques involve grouting and curing in the low-temperature environment of the ice layer, making construction complex, quality difficult to guarantee, and the application of low-temperature resistant grouting materials inevitably impacts the polar environment.

[0003] Given the technical deficiencies of existing technologies, there is an urgent need for a new type of construction method suitable for ice sheet regions such as the North and South Poles to resist pull-out. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a construction method for ice layer expansion head self-locking anchor bolts, which does not use any cementing materials, requires no pouring or curing, is convenient and quick to construct, and the materials are easy to transport and carry, resulting in zero pollution on site.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A construction method for a self-locking anchor bolt with an expanded head in ice layer, characterized by comprising the following steps: S1: Use a drill bit to form a hole and make the hole penetrate through the snow and freeze-thaw layer and into the permafrost layer; S2: Insert the ice layer reamer self-locking anchor into the borehole. The ice layer reamer self-locking anchor includes an anchor body and a reamer device disposed at the lower end of the anchor body, wherein the reamer device is located at the bottom of the borehole. S3: Fill the borehole with water; S4: After the water has frozen, pass the pre-reserved connecting part at the top of the anchor rod through the pre-reserved hole in the foundation and connect it to the foundation, thus completing the construction of the ice-enlarged self-locking anchor rod.

[0006] Preferably, the anchor rod body includes the connection portion reserved at the top and the externally reinforced rod body located in the borehole. The lower end of the reinforced rod body is provided with an external thread. The expansion device includes an anchoring disc threaded to the lower end of the reinforced rod body and an end plate fixing member that fixes the anchoring disc to the lower end of the reinforced rod body.

[0007] Preferably, the length of the reinforcing rod is 3-8m and the diameter is 20-40mm, and the diameter of the anchoring disc is 130-270mm.

[0008] Preferably, step S1 further includes forming a reaming hole below the drilled hole using a reaming drill bit, wherein the diameter of the reaming hole is larger than the diameter of the drilled hole; the reaming device is an expandable reaming device, and in step S2, the reaming device is positioned in the reaming hole, and after the reaming device is positioned in the reaming hole, the reaming device is switched from a closed state to an expanded state, wherein when the reaming device is in the expanded state, it is fully expanded to form a circular surface, and the diameter of the circular surface is larger than the diameter of the drilled hole.

[0009] Preferably, the upper part of the anchor rod body is provided with an external thread and fitted with a locking nut, and the middle part is fitted with an outer sleeve with external ribs. The outer sleeve can be fixed to the anchor rod body by a fixing pin. The expanding device includes an upper anchor fixed to the lower end of the outer sleeve and a lower anchor fixed to the lower end of the anchor rod body. The upper anchor has multiple upper blades through an upper rotating shaft, and the lower anchor has multiple lower blades through a lower rotating shaft. The multiple upper blades and multiple lower blades are staggered on the horizontal plane and can be converted from a closed state to an unfolded state. In step S2, after the expanding device is placed in the reaming hole, the fixing pin is pulled out and the outer sleeve is pushed to slide downward, so that the multiple upper blades and multiple lower blades are converted from a closed state to an unfolded state and fully unfolded to form a circular surface. Then, the locking nut is tightened so that the locking nut abuts against the upper end of the outer sleeve, thereby locking the multiple upper blades and multiple lower blades in the unfolded state.

[0010] Preferably, the outer sleeve has a plurality of spaced-apart ventilation holes along the axial direction.

[0011] Preferably, the anchor rod body includes the connection portion reserved at the top, a ribbed rod body with external reinforcement located in the borehole, and an anchor head set at the end. The expanding device includes an upper anchor and a lower anchor. The upper anchor is located at the lower end of the ribbed rod body and above the anchor head. The upper anchor has multiple upper blades via an upper rotating shaft, and the lower anchor has multiple lower blades via a lower rotating shaft. The lower anchor also has a finished groove. The lower blades are connected to the upper blades. The multiple upper blades and multiple lower blades are staggered on the horizontal plane and can be converted from a closed state to an unfolded state. In step S2, after the expanding device is placed in the expanded borehole, the anchor rod body is pressed or hammered to convert the multiple upper blades and multiple lower blades from a closed state to an unfolded state and fully unfold to form a circular surface. At the same time, the anchor head is embedded in the finished groove, thereby locking the multiple upper blades and multiple lower blades in the unfolded state.

[0012] Preferably, the upper and lower blades are provided with perforations, and the multiple upper blades and multiple lower blades can be closed by a rope passing through the perforations.

[0013] Preferably, when the plurality of upper blades and the plurality of lower blades are in an unfolded state and fully unfolded to form a circular surface, there is a gap between adjacent upper blades and lower blades.

[0014] Preferably, the length of the anchor rod is 3-8m and the diameter is 20-40mm, and the diameter of the circular surface formed by the multiple upper blades and multiple lower blades when fully unfolded is 130-270mm.

[0015] Compared with the prior art, the construction method of the ice layer enlarged head self-locking anchor bolt of the present invention has one or more of the following beneficial technical effects: 1. The present invention sets up an enlarged self-locking anchor in the ice layer area, and reliably transfers the pull-out force of the upper structure of the building to the permafrost layer through the enlarged self-locking anchor, thus solving the pull-out resistance problem of buildings in the ice layer area.

[0016] 2. This invention involves drilling holes in the permafrost and installing self-locking anchor bolts with expanded ice heads. After installation, water is poured in to solidify the anchor bolts. Apart from the metal self-locking anchor bolts with expanded ice heads, no other cementing materials are used. No pouring or curing is required. Construction is convenient and quick, materials are easy to transport and carry, there is zero pollution on site, and it will not affect the fragile polar environment. Attached Figure Description

[0017] Figure 1 A schematic diagram of the construction of the ice layer expansion head self-locking anchor bolt of the present invention is shown.

[0018] Figure 2 This is a schematic diagram of the ice-layer expansion head self-locking anchor rod of the present invention when the metal material is damaged.

[0019] Figure 3 This is a schematic diagram of the self-locking anchor rod of the ice layer expansion head of the present invention when the cylindrical ice body is pulled out and destroyed.

[0020] Figure 4 This is a schematic diagram of the ice layer expansion head self-locking anchor rod of the present invention when the inverted cone is pulled out and destroyed.

[0021] Figure 5 This is a schematic diagram of the ice layer expansion head self-locking anchor bolt of the present invention under local pressure failure.

[0022] Figure 6 A schematic diagram of the drilling process for constructing an ice-layer enlarged head self-locking anchor bolt according to an embodiment of the present invention is shown.

[0023] Figure 7A schematic diagram of an ice-layer expansion head self-locking anchor bolt according to an embodiment of the present invention is shown.

[0024] Figure 8 yes Figure 7 Sectional view 1-1.

[0025] Figure 9 A schematic diagram of the drilling process for constructing an ice-layer enlarged self-locking anchor bolt according to another embodiment of the present invention is shown.

[0026] Figure 10 A schematic diagram of another embodiment of the ice layer expansion head self-locking anchor rod of the present invention is shown when the blade is in the closed state.

[0027] Figure 11 A schematic diagram of another embodiment of the ice-layer expansion head self-locking anchor bolt with the blade in the deployed state is shown.

[0028] Figure 12 yes Figure 11 Enlarged sectional view 2-2.

[0029] Figure 13 A schematic diagram of the ice-layer expansion head self-locking anchor bolt of another embodiment of the present invention is shown when the blade is in the closed state.

[0030] Figure 14 A schematic diagram of the ice-layer expansion head self-locking anchor bolt of another embodiment of the present invention is shown when the blade is in the deployed state.

[0031] Figure 15 yes Figure 14 Enlarged sectional view (3-3). Detailed Implementation

[0032] Before detailing any embodiment of the invention, it should be understood that the invention, in its application, is not limited to the details of the construction and arrangement of the components set forth in the following description or illustrated in the following figures. The invention can have other embodiments and can be practiced or carried out in various ways. Furthermore, it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered limiting. The use of “comprising” or “having” and variations thereof is intended to cover the items set forth below and their equivalents, as well as any additional items. Unless otherwise specified or limited, the terms “installation,” “connection,” “support,” and “linkage,” and variations thereof are used broadly and cover both direct and indirect installation, connection, support, and linking. Moreover, “connection” and “linkage” are not limited to physical or mechanical connections or links. Furthermore, firstly, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention. Secondly, the term "a" should be understood as "at least one" or "one or more," that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple. The term "a" should not be construed as a limitation on the quantity.

[0033] Figure 1 A schematic diagram of the construction of the ice-layer enlarged head self-locking anchor bolt of the present invention is shown. Figure 1 As shown, the construction method of the ice layer expansion head self-locking anchor bolt of the present invention includes the following steps: S1: Drilling.

[0034] A drill hole 8 is formed using a drill bit. Since the work is being carried out in ice-covered regions such as the Arctic and Antarctic, the depth of the drill hole involves the overlying snow and freeze-thaw layer 6 and the permafrost layer 7 located below the snow and freeze-thaw layer 6. In this invention, the drill hole 8 is drilled so that it penetrates the snow and freeze-thaw layer 6 and extends into the permafrost layer 7.

[0035] S2: Install ice layer expansion head self-locking anchor bolts.

[0036] The ice-enlarged self-locking anchor bolt includes an anchor bolt body 1 and an enlarging device 2 located at the lower end of the anchor bolt body 1. When installing the ice-enlarged self-locking anchor bolt, it is inserted into the drilled hole 8, with the enlarging device 2 positioned at the bottom of the drilled hole 8. Simultaneously, the pre-reserved connecting portion at the top of the anchor bolt body 1 is located outside the drilled hole 8.

[0037] S3: Watering.

[0038] After the ice layer expansion head self-locking anchor is installed into the borehole 8, water is filled into the borehole 8.

[0039] S4: Connect to the base.

[0040] After the water freezes, it connects with the permafrost layer 7, increasing its pull-out resistance. Then, the pre-reserved connecting part at the top of the anchor rod 1 is passed through the reserved hole in the foundation of the building and connected to the foundation (for example, by connecting to the foundation through an end plate and nut), thus completing the construction of the ice-enlarged self-locking anchor rod.

[0041] To ensure that the construction method of the ice-enlarged self-locking anchor bolt used in this invention has sufficient resistance to damage, the inventors analyzed and calculated its failure modes so that those skilled in the art can select appropriate dimensions for each component of the ice-enlarged self-locking anchor bolt according to the requirements of resistance to damage.

[0042] Depending on the magnitude of the pull-out load, the properties and temperature of the permafrost layer, the borehole diameter, the borehole depth, and the size of the reamer, there may be four different failure modes. The actual pull-out bearing capacity should ultimately be determined by testing. Before the test, a preliminary estimate can be made based on the different failure modes. The significance of the calculation parameters involved in the estimate is as follows: The diameter d1 of the connecting part 1-1 of the anchor rod body, in mm; The diameter d2 of the reinforced rod 1-2 of the anchor bolt body, in mm; The diameter D1 of borehole 8, in mm; The diameter D2 of the reaming drill hole 9 is in mm; The diameter D3 of the expanded head device 2 after unfolding is in mm; Net area A after expansion device 2 is unfolded sn Unit: mm 2 ; The total thickness L1 of the snow cover and freeze-thaw layer 6, in meters; The length L2 of borehole 8 in the permafrost layer 7, in meters; The length L3 of the enlarged borehole 9 in the permafrost layer 7, in meters; Standard value of compressive strength f of ice ick Unit: MPa; Standard value of tensile strength f of ice itk Unit: MPa; Standard value of shear strength f of ice iτk Unit: MPa; The tensile strength f of the anchor rod body syk Unit: MPa; The bond strength f between the anchor rod and the ice layer sik Unit: MPa; Safety factor values ​​for different failure modes: K1, K2, K3, K4; Comprehensive empirical coefficients for different failure modes, φ1, φ2, φ3, φ 4a φ 4b .

[0043] 1. Failure Mode 1 - Failure of metallic materials.

[0044] like Figure 2As shown, under the action of upward pulling force, the anchor rod 1 of the ice layer expansion head self-locking anchor rod may break or the connection between the anchor rod 1 and the expansion head device 2 may be damaged. This kind of damage can be avoided by controlling the size and strength of the metal material.

[0045] When designing the ice-layer expanded head self-locking anchor bolt, the strength of the expanded head device and its connection with the anchor bolt body must be greater than the tensile strength of the anchor bolt body. Therefore, in the event of metal material failure, the pull-out bearing capacity N of the anchor bolt body must be greater than the tensile strength of the anchor bolt body. itk1 for: N itk1 =φ1*f syk *As / K1=φ1*π*d2*f syk / K1.

[0046] 2. Destruction Mode Two - Cylindrical Ice Body Pulling Out Destruction.

[0047] like Figure 3 As shown, under the action of the upward pulling force, the shear strength between the cylindrical ice body and the permafrost layer 7 within the range of the expanding head device 2 is insufficient, and the cylindrical ice body is sheared and broken, and is pulled out as a whole.

[0048] When a cylindrical ice body is pulled out and fails, the pull-out bearing capacity N itk2 The shear strength between the cylindrical ice body corresponding to the expanding head device 2 and the surrounding ice layer is controlled: N itk2 =φ2*π*D3 2 *(L2+L3)*f iτk / K2.

[0049] 3. Failure Mode Three - Inverted Cone Pull-out Failure.

[0050] like Figure 4 As shown, under the action of the upward pulling force, oblique principal tensile stress is generated in the ice layer. When the tensile strength of the ice layer is lower than the principal tensile stress, the inverted cone pull-out failure with the expanding head device 2 as the apex occurs, which is similar to the punching failure in brittle materials such as concrete and rock.

[0051] Bearing capacity N of the pull-out failure mode of the inverted cone itk3 The main influencing factors include the standard value of the tensile strength of the ice layer, the size of the expanding head device 2, the embedment depth of the expanding head device 2 (affecting the surface area of ​​the inverted cone), and the diffusion angle α of the punching surface, etc. N itk3 =φ3*F(f itk ,D3,L2,L3,α) / K3.

[0052] 4. Damage Mode Four - Local Pressure Damage.

[0053] like Figure 5As shown, under the action of upward pulling force, the expanding head device 2 exerts a squeezing effect on the ice layer. When the compressive strength of the ice layer is less than the pressure value, local pressure failure of the ice body occurs at the expanding head device 2.

[0054] When external tension is transmitted to the expansion device 2, part of the tension will be borne by the bond force between the anchor rod body 1 and the permafrost layer. Therefore, the pull-out bearing capacity N when local pressure failure occurs... itk4 The bonding resistance N between the anchor rod body 1 and the permafrost layer itk4a The ice pressure reaction force N of the expansion head device 2 itk4b composition.

[0055] Similar to the calculation of the side bond strength of traditional anchor bolts, the bond resistance N between anchor bolt body 1 and the permafrost layer... itk4a The surface area of ​​anchor rod 1, the length of anchor rod 1, and the bonding strength f between anchor rod 1 and the ice layer are determined by... sik The control is as follows: φ is the influence coefficient of the anchorage length of anchor rod 1 on the bonding force.

[0056] N itk4a =φ 4a *(π·d2·f sik ·φ·L2) / K4.

[0057] Local pressure reaction force N of the head expansion device itk4b The dimensions of the expanding head device 2 (net area A) sn ), the standard value of compressive strength f of ice layer ick The local pressure correction factor β1 and the confining pressure correction factor β2 are controlled by these factors.

[0058] N itk4b =φ 4b *(β1·β2·f ick ·A sn ) / K4.

[0059] Comprehensive pull-out bearing capacity N under local pressure failure itk4 for: N itk4 =N itk4a +N itk4b .

[0060] The estimation of ice-related failure modes shows that, given sufficient length of anchor rod 1, the pull-out bearing capacity of the inverted cone is significantly higher than other failure modes, followed by shear failure of the cylinder, with localized ice pressure failure exhibiting the lowest bearing capacity. Considering that the bearing capacity of anchor rod 1 can be increased through variations in material strength and diameter, N can be controlled in practical applications. itk1 ≥min(N) itk2 N itk3 N itk4 ).

[0061] Therefore, the actual pull-out bearing capacity of ice-covered self-locking anchors is most affected by the local pressure failure mode of the ice layer. An effective way to adjust its bearing capacity is to increase the length or diameter of the anchor rod to increase the bond anchoring force N. itk4a Alternatively, increase the size of the expanding device to increase its pressure resistance (N). itk4b .

[0062] Based on the above calculation formula, the inventors have listed reference dimensions for different anchor rod diameters, effective bond lengths of anchor rods, and expansion heads corresponding to conventional pull-out bearing capacities of 150kN to 300kN, which can be used as a reference when designing the ice layer expansion head self-locking anchor rod.

[0063] The relationship between the diameter d2 of the anchor rod and the pull-out bearing capacity is shown in Table 1 when the diameter D3 of the expansion device is 230mm and the effective bonding length L2+L3 of the anchor rod is 4m.

[0064] Table 1 The relationship between the diameter d2 of the anchor rod and the pull-out bearing capacity is shown in Table 2 when the diameter D3 of the expansion device is 230mm and the effective bonding length L2+L3 of the anchor rod is 6m.

[0065] Table 2 The relationship between the length L2 of the anchor rod and the pull-out bearing capacity is shown in Table 3 when the diameter D3 of the expansion device is 230 mm and the diameter d2 of the anchor rod is 25 mm.

[0066] Table 3 The relationship between the diameter D3 of the expansion device and the pull-out bearing capacity is shown in Table 4 when the diameter d2 of the anchor rod is 25mm and the effective bonding length L2+L3 of the anchor rod is 6m.

[0067] Table 4 When designing the ice layer expansion head self-locking anchor, the appropriate dimensions of each component of the ice layer expansion head self-locking anchor can be selected based on the pull-out bearing capacity requirements.

[0068] The specific implementation of the present invention will be described in detail below with reference to several specific embodiments.

[0069] like Figure 6-8As shown, in one embodiment of the present invention, the drill hole 8 is a hole with a larger diameter than the diameter of the reaming device 2. During construction, the drill hole 8 is drilled directly using a large drill bit.

[0070] In this embodiment, the anchor rod 1 includes a pre-reserved connecting portion 1-1 at the top and a reinforced rod 1-2 located within the borehole 8. The connecting portion 1-1 is used for connection to the foundation of the building. The reinforced rod 1-2 is inserted into the borehole 8 to achieve anchoring and pull-out resistance.

[0071] The lower end of the ribbed rod 1-2 is provided with external threads. The expanding device 2 includes an anchoring disc 2-1 threadedly connected to the lower end of the ribbed rod 1-2 and an end plate fixing member 2-2 that fixes the anchoring disc 2-1 to the lower end of the ribbed rod 1-2. By making the ribbed rod 1-2 externally ribbed, the friction between it and the ice is increased, making it difficult to pull out of the frozen ice and improving its pull-out resistance. At the same time, by setting the expanding device 2, it is even more difficult to pull out of the frozen ice, further improving its pull-out resistance.

[0072] All components in this embodiment are made of stainless steel. The dimensions of each component can be adjusted according to the diameter D3 of the expanding head device 2. Preferably, when the diameter D3 of the anchoring disc 2-1 is 230mm, the diameter D1 of the drill hole 8 is 250mm, the thickness of the anchoring disc 2-1 is 8mm~30mm, and the thickness of the end plate fixing member 2-2 is 50mm.

[0073] like Figure 9-12 As shown, in another embodiment of the present invention, a small-diameter hole 8 is first drilled in the snow and freeze-thaw layer 6 and the permafrost layer 7 located below the snow and freeze-thaw layer 6. After drilling to a certain depth, the reaming bit is unfolded to form a reaming hole 9 below the hole 8, such that the diameter of the reaming hole 9 is larger than the diameter of the hole 8. Simultaneously, the reaming device 2 is a deployable reaming device and is located within the reaming hole 9.

[0074] After positioning the reaming device 2 within the reaming borehole 9, the reaming device 2 can be removed from... Figure 10 The closing state shown transitions to Figure 11 The expanded state is shown. Specifically, the expanding head device 2 is in the expanded state... Figure 10 When the device is in the closed position as shown, its diameter is smaller than the diameter of the drill hole 8, so as to facilitate its placement into the reaming drill hole 9. And when the reaming device 2 is in... Figure 11When in the unfolded state shown, its diameter is larger than the diameter of the drill hole 8, so as to prevent it from coming out of the enlarged drill hole 9.

[0075] In this embodiment, preferably, the upper part of the anchor rod body 1 is provided with external threads and fitted with a locking nut 5, and the middle part is fitted with an outer sleeve 3 with external reinforcement.

[0076] Preferably, the upper part of the anchor rod body 1 and the outer sleeve 3 are provided with opposite fixing holes, so that the outer sleeve 3 can be fixed to the anchor rod body 1 by a fixing pin 4 passing through the fixing hole.

[0077] The expanding head device 2 includes an upper anchor 2-3 fixed to the lower end of the outer sleeve 3 and a lower anchor 2-6 fixed to the lower end of the anchor rod body 1. The upper anchor 2-3 has multiple upper blades 2-4 mounted on an upper rotating shaft 2-5 to allow the upper blades 2-4 to rotate relative to the upper anchor 2-3, thereby enabling rotation from... Figure 10 The closing state shown transitions to Figure 11 The unfolded state is shown. Similarly, the lower anchor 2-6 is provided with multiple lower blades 2-7 via a lower rotating shaft 2-8 so that the lower blades 2-7 can rotate relative to the lower anchor 2-6, thereby enabling movement from... Figure 10 The closing state shown transitions to Figure 11 The unfolded state shown.

[0078] like Figure 12 As shown, the plurality of upper blades 2-4 and the plurality of lower blades 2-7 are staggered on a horizontal plane and can be switched from a closed state to an unfolded state. Preferably, there are four upper blades 2-4 and four lower blades 2-7, and they are all fan-shaped, so that they can form a circular surface together after unfolding.

[0079] More preferably, when the plurality of upper blades 2-4 and the plurality of lower blades 2-7 are in the unfolded state and fully unfolded to form a circular surface, there is a gap between adjacent upper blades 2-4 and lower blades 2-7. For example, there is a gap of about 3 mm to facilitate on-site implementation and ensure installation accuracy.

[0080] Furthermore, in this invention, such as Figure 12 As shown, both the upper blade 2-4 and the lower blade 2-7 are provided with perforations 2-9. Thus, by passing a rope (such as an elastic rope or a thin steel wire) through the perforations 2-9, the multiple upper blades 2-4 can be brought into a closed state, and the multiple lower blades 2-7 can also be brought into a closed state.

[0081] During actual construction, before installation, the upper blade 2-4 and lower blade 2-7 are temporarily fixed using elastic ropes or thin steel wires through the perforations 2-9, so that they are in a closed state. At the same time, the fixing pin 4 passes through the fixing hole provided in the upper part of the anchor rod body 1 and the outer sleeve 3 to fix the outer sleeve 3 to the anchor rod body 1, so as to prevent the outer sleeve 3 from sliding down and causing the upper blade 2-4 and lower blade 2-7 to unfold prematurely.

[0082] During installation, first install the anchor rod body 1 into the drill hole 8 and position the reaming device 2 in the reaming drill hole 9. After the anchor rod body 1 is in place, pull out the fixing pin 4 and push the outer sleeve 3 downwards. The outer sleeve 3 then expands the elastic rope or thin steel wire temporarily fixing the upper blade 2-4 and lower blade 2-7, allowing the upper blade 2-4 and lower blade 2-7 to fully unfold and form a circular surface. Finally, tighten the locking nut 5 on the upper part of the anchor rod body 1 so that the locking nut 5 presses against the upper end of the outer sleeve 3, completing the locking of the outer sleeve 3 and the upper blade 2-4 and lower blade 2-7, thereby locking the multiple upper blades 2-4 and multiple lower blades 2-7 in the unfolded state.

[0083] Then, water can be filled into the drilled hole 8 and the enlarged drilled hole 9. After the water freezes, the pre-reserved connecting part at the top of the anchor rod body 1 can be passed through the pre-reserved hole in the foundation and connected to the foundation (for example, by connecting to the foundation through an end plate and a nut), thus completing the construction of the ice-enlarged self-locking anchor rod.

[0084] In this embodiment, to avoid the problem of frost heave caused by ice forming in the gap between the outer sleeve 3 and the anchor rod body 1, vent holes with a diameter of 5mm can be reserved in the axial direction of the outer sleeve 3 at 500mm intervals.

[0085] All components used in this embodiment are made of stainless steel. The dimensions of each component can be adjusted according to the diameter of the expanding head device 2. Preferably, when the diameter D3 of the circular surface formed by the fully expanded upper blade 2-4 and lower blade 2-7 is 230mm, the diameter D1 of the drill hole 8 is 130mm, the diameter D2 of the expanding drill hole 9 is 250mm, the depth L3 of the expanding drill hole 9 is 300mm, the thickness of the upper anchor 2-3 and lower anchor 2-6 is 50mm~80mm, the thickness of the upper blade 2-4 and lower blade 2-7 is 8mm~20mm, the wall thickness of the outer sleeve 3 is 6mm, and the gap between the outer sleeve 3 and the anchor rod body 1 is 1.5mm.

[0086] In yet another embodiment of the invention, similar to the previous embodiment, a small-diameter hole 8 is first drilled in the snow and freeze-thaw layer 6 and the permafrost layer 7 located below the snow and freeze-thaw layer 6. After drilling to a certain depth, the reaming bit is unfolded to form a reaming hole 9 below the hole 8, with the diameter of the reaming hole 9 being larger than the diameter of the hole 8. Simultaneously, the reaming device 2 is a deployable reaming device, and the reaming device 2 is located within the reaming hole 9.

[0087] Unlike the other embodiment described above, as Figure 13-15 As shown, the anchor rod body 1 includes the connection part 1-1 reserved at the top, the externally reinforced rod body 1-2 located in the drill hole 8, and the anchor head 1-3 set at the end.

[0088] Similarly, the expanding head device 2 includes an upper anchor 2-3 and a lower anchor 2-6. The upper anchor 2-3 is located at the lower end of the ribbed rod 1-2 and above the anchor head 1-3. Multiple upper blades 2-4 are provided on the upper anchor 2-3 via an upper rotating shaft 2-5. Multiple lower blades 2-7 are provided on the lower anchor 2-6 via a lower rotating shaft 2-8.

[0089] The difference is that the lower anchor 2-6 also has a finished product slot 2-10. Furthermore, the lower blade 2-7 is connected to the upper blade 2-4 so that the lower anchor 2-6 can be connected to the anchor rod body 1, that is, so that the lower anchor 2-6 is suspended directly below the upper anchor 2-3.

[0090] Preferably, such as Figure 15 As shown, both the upper blade 2-4 and the lower blade 2-7 are provided with through holes 2-9. Thus, a rope (e.g., an elastic rope or a thin steel wire) passing through the through holes 2-9 can bring the multiple upper blades 2-4 into a closed state, and also bring the multiple lower blades 2-7 into a closed state. Simultaneously, the rope passing through the through holes 2-9 can connect the lower blades 2-7 to the upper blades 2-4, so that the lower anchor 2-6 can be suspended directly below the upper anchor 2-3.

[0091] Similarly, the plurality of upper blades 2-4 and the plurality of lower blades 2-7 are staggered on the horizontal plane and can be... Figure 13 The closing state shown transitions to Figure 14 The unfolded state shown.

[0092] During the actual construction, before installation, the upper blade 2-4 and the lower blade 2-7 are temporarily fixed with elastic ropes or thin steel wires using the perforations 2-9 in the upper blade 2-4 and the lower blade 2-7 to make them close together, and the lower anchor 2-6 is suspended directly below the upper anchor 2-3.

[0093] During installation, first install the anchor rod body 1 into the drill hole 8 and position the reaming device 2 in the reaming drill hole 9. After the anchor rod body 1 is in place, quickly press or hammer the anchor rod body 1. Under the squeezing action of the upper anchor 2-3 and lower anchor 2-6, the elastic rope or thin steel wire temporarily fixing the upper blade 2-4 and lower blade 2-7 is opened, allowing the multiple upper blades 2-4 and multiple lower blades 2-7 to... Figure 13 The closing state shown transitions to Figure 14 The unfolded state shown and the fully unfolded composition are as follows: Figure 15 The circular surface is shown. At the same time, the anchor head 1-3 is embedded into the finished product slot 2-10, thereby locking the multiple upper blades 2-4 and multiple lower blades 2-7 in the unfolded state.

[0094] All components in this embodiment are made of stainless steel. The dimensions of each component can be adjusted according to the diameter of the expanding head device 2. Preferably, when the diameter D3 of the circular surface formed by the fully expanded upper blade 2-4 and lower blade 2-7 is 230mm, the diameter D1 of the drill hole 8 is 130mm, the diameter D2 of the expanding drill hole 9 is 250mm, the depth L3 of the expanding drill hole 9 is 300mm, the thickness of the upper anchor 2-3 is 50mm~60mm, the thickness of the lower anchor 2-6 is 90mm~100mm, and the thickness of the upper blade 2-4 and lower blade 2-7 is 8mm~20mm.

[0095] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Those skilled in the art can modify or make equivalent substitutions to the technical solutions of the present invention based on the concept of the present invention, without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A construction method for a self-locking anchor bolt with an expanded head in ice layer, characterized in that, Includes the following steps: S1: Use a drill bit to form a hole (8) and make the hole (8) penetrate through the snow and freeze-thaw layer (6) and into the permafrost layer (7); S2: Insert the ice layer reamer self-locking anchor into the borehole (8). The ice layer reamer self-locking anchor includes an anchor rod body (1) and a reamer device (2) disposed at the lower end of the anchor rod body (1), wherein the reamer device (2) is located at the bottom of the borehole (8). S3: Fill the borehole (8) with water; S4: After the water has frozen, the pre-reserved connection part (1-1) at the top of the anchor rod body (1) is passed through the reserved hole of the foundation and connected to the foundation, thus completing the construction of the ice layer expansion head self-locking anchor rod.

2. The construction method of the ice layer enlargement head self-locking anchor bolt according to claim 1, characterized in that, The anchor rod body (1) includes the connection part (1-1) reserved at the top and the externally reinforced rod body (1-2) located in the drill hole (8). The lower end of the reinforced rod body (1-2) is provided with external threads. The expansion device (2) includes an anchoring disc (2-1) threaded to the lower end of the reinforced rod body (1-2) and an end plate fixing member (2-2) that fixes the anchoring disc (2-1) to the lower end of the reinforced rod body (1-2).

3. The construction method of the ice layer enlarged head self-locking anchor bolt according to claim 2, characterized in that, The length of the reinforcing bar (1-2) is 3-8m and the diameter is 20-40mm, and the diameter of the anchoring disc (2-1) is 130-270mm.

4. The construction method of the ice layer enlargement head self-locking anchor bolt according to claim 1, characterized in that, Step S1 further includes forming a reaming hole (9) below the borehole (8) using a reaming drill bit, and the diameter of the reaming hole (9) is larger than the diameter of the borehole (8); the reaming head device (2) is an expandable reaming head device, and in step S2, the reaming head device (2) is placed in the reaming hole (9), and after the reaming head device (2) is placed in the reaming hole (9), the reaming head device (2) is switched from a closed state to an expanded state. When the reaming head device (2) is in the expanded state, it is fully expanded to form a circular surface, and the diameter of the circular surface is larger than the diameter of the borehole (8).

5. The construction method of the ice layer enlargement head self-locking anchor bolt according to claim 4, characterized in that, The upper part of the anchor rod body (1) is provided with an external thread and fitted with a locking nut (5), and the middle part is fitted with an outer sleeve (3) with external reinforcement. The outer sleeve (3) can be fixed to the anchor rod body (1) by a fixing pin (4). The expansion device (2) includes an upper anchor (2-3) fixed to the lower end of the outer sleeve (3) and a lower anchor (2-6) fixed to the lower end of the anchor rod body (1). The upper anchor (2-3) is provided with multiple upper blades (2-4) through an upper rotating shaft (2-5), and the lower anchor (2-6) is provided with multiple lower blades (2-7) through a lower rotating shaft (2-8). The multiple upper blades (2-4) -4) and multiple lower blades (2-7) are staggered on the horizontal plane and can be switched from the closed state to the unfolded state. In step S2, after the expanding head device (2) is placed in the expanding hole (9), the fixing pin (4) is pulled out and the outer sleeve (3) is pushed to slide downward, so that the multiple upper blades (2-4) and multiple lower blades (2-7) are switched from the closed state to the unfolded state and fully unfolded to form a circular surface. Then, the locking nut (5) is tightened so that the locking nut (5) abuts against the upper end of the outer sleeve (3), thereby locking the multiple upper blades (2-4) and multiple lower blades (2-7) in the unfolded state.

6. The construction method of the ice layer enlargement head self-locking anchor bolt according to claim 5, characterized in that, The outer sleeve (3) has multiple spaced-apart ventilation holes along the axial direction.

7. The construction method of the ice layer enlargement head self-locking anchor bolt according to claim 4, characterized in that, The anchor rod body (1) includes the pre-reserved connecting part (1-1) at the top, the externally reinforced rod body (1-2) located in the drill hole (8), and the anchor head (1-3) at the end. The head expansion device (2) includes an upper anchor (2-3) and a lower anchor (2-6). The upper anchor (2-3) is located at the lower end of the reinforced rod body (1-2) and above the anchor head (1-3). The upper anchor (2-3) is provided with multiple upper blades (2-4) via an upper rotating shaft (2-5). The lower anchor (2-6) is provided with multiple lower blades (2-7) via a lower rotating shaft (2-8). The lower anchor (2-6) is also provided with a finished product slot (2-1). 0), the lower blade (2-7) is connected to the upper blade (2-4), the multiple upper blades (2-4) and multiple lower blades (2-7) are staggered on the horizontal plane and can be converted from the closed state to the unfolded state. In step S2, after the head expansion device (2) is placed in the hole expansion drill (9), the anchor rod body (1) is pressed or hammered, so that the multiple upper blades (2-4) and multiple lower blades (2-7) are converted from the closed state to the unfolded state and fully unfolded to form a circular surface. At the same time, the anchor head (1-3) is embedded in the finished product slot (2-10), thereby locking the multiple upper blades (2-4) and multiple lower blades (2-7) in the unfolded state.

8. The construction method of the ice layer enlargement head self-locking anchor bolt according to any one of claims 4-7, characterized in that, Both the upper blade (2-4) and the lower blade (2-7) are provided with perforations (2-9), and the multiple upper blades (2-4) and the multiple lower blades (2-7) can be closed by passing a rope through the perforations (2-9).

9. The construction method of the ice layer enlargement head self-locking anchor bolt according to claim 8, characterized in that, When the plurality of upper blades (2-4) and the plurality of lower blades (2-7) are in an unfolded state and fully unfolded to form a circular surface, there is a gap between adjacent upper blades (2-4) and lower blades (2-7).

10. The construction method of the ice layer enlargement head self-locking anchor bolt according to claim 9, characterized in that, The length of the anchor rod (1) is 3-8m and the diameter is 20-40mm. The diameter of the circular surface formed by the multiple upper blades (2-4) and multiple lower blades (2-7) when fully unfolded is 130-270mm.

Images