An anti-floating anchor rod structure for existing building and construction method

Abstract

The application discloses an anti-floating anchor rod structure for an existing building and a construction method thereof. The anti-floating anchor rod structure for the existing building is characterized by comprising a grouting anchor rod, an anchoring plate and a locking structure. The grouting anchor rod is a steel pipe, one open end of the grouting anchor rod is a grouting opening, the pipe wall of the steel pipe is provided with a grouting hole and a grout inlet hole, and the pipe wall of the steel pipe is fixedly connected with a special-shaped structure. The anchoring plate is provided with a through hole at a central position, the grouting anchor rod passes through the through hole, and the axis of the through hole is coincident with the axis of the grouting anchor rod. The application organically combines grouting reinforcement and the anti-floating anchor rod, utilizes the self weight of the geological structure itself to resist the buoyancy generated by the underground water, reversely realizes the thickening of the waterproof bottom plate by utilizing the grouting reinforcement, provides structural support for the application of the anchor rod prestress, and can be widely applied to the anti-floating and anti-seepage treatment of various underground structures, and can improve the anti-floating capacity of the existing building and reduce the underground water seepage risk.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of geotechnical construction, and relates to the technical field of building foundation anti-floating and geotechnological anti-seepage reinforcement, in particular to an existing building anti-floating anchor rod structure and a construction method. BACKGROUND

[0002] With the increasingly nervous development and utilization of surface space, the development of underground space gradually becomes the focus of urban construction. The "square building" composed of main buildings, low podiums and large-area basement structures becomes a construction hotspot, but the accompanying engineering problems also increase significantly. With the increase of the depth of the basement, the depth of the foundation pit and the depth of the foundation are also increased, and the buoyancy generated by the underground water is also increased. In the "square building" structure, the height of the main building exceeds 15 layers, and its self-weight can meet the anti-floating requirements. The height of the podium is usually less than 6 layers, and its structural self-weight is lighter. When the buoyancy of the underground water is greater than the self-weight, the waterproof floor of the building structure is uplifted, cracked, partially damaged or even floated, even the structure is damaged, which affects the safe use and operation of the building structure. Especially in recent years, with the climate change, the rainfall in summer increases significantly, which causes the underground water level in local areas to be higher than the historical water level, and the underground water level is higher than the anti-floating water level. The self-weight of the existing anti-floating structure is less than the buoyancy of the underground water, which causes the building floor to be uplifted and cracked. Therefore, in order to effectively cope with the adverse effects of the rising underground water level on the building structure, the design and implementation of the anti-floating structure are very important.

[0003] The common anti-floating structures such as anti-floating anchor rods and anti-floating piles are implemented before the construction of the building foundation, and are combined with the foundation to form an anti-floating structure. For the anti-floating treatment of the existing building, the self-weight is usually increased by increasing the thickness of the raft (waterproof floor) and increasing the basement load; the method of intercepting and draining water is used to reduce the buoyancy of the underground water. However, the above methods have certain limitations. For example, in the existing building, due to the limitation of space, the construction of the anchor rod is restricted; due to the high underground water level, the drilling is in a gushing state, which causes the grout to be eroded by the underground water, unable to coagulate or the strength and solidity of the stone body to be reduced, and then the anti-floating structure is difficult to reach the design value or fails; the thickening of the raft and the load increase the space structure of the basement, which affects the use and greatly increases the engineering cost; in sandy soil, gravel soil and soft soil layer, long-term underground drainage and drainage can easily cause the loss of fine particles, increase the pore of the foundation, weaken the structural strength of the foundation soil, and rearrange the particles to cause the foundation to have a cavity and collapse, thereby reducing the bearing capacity of the foundation and endangering the stability of the upper building.

[0004] Therefore, a new anti-floating and anti-seepage structure is needed for the existing building in the water-rich sand layer, which can balance the buoyancy and achieve the purpose of reinforcing the layer to improve the bearing and anti-seepage. SUMMARY

[0005] To address the aforementioned technical problems, this invention provides an anti-buoyancy anchor structure and construction method for existing buildings.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A buoyancy-resistant anchor structure for existing buildings is provided, characterized in that it includes,

[0008] Grouting anchor bolts, anchor plates, and locking structures;

[0009] The grouting anchor rod is a steel pipe, one open end of which is a grouting port. The steel pipe wall is provided with grouting holes and grout inlet holes, and the steel pipe wall is fixedly connected to the irregular structure.

[0010] The anchor plate has a through hole at its center, through which the grouting anchor rod passes. The axis of the through hole coincides with the axis of the grouting anchor rod, and the distance between the anchor plate and the grouting port is 10cm-20cm.

[0011] The locking structure is located on the side of the anchor plate facing the grouting port, and the locking structure is used to prevent the grouting anchor rod from shifting from the anchor plate.

[0012] Preferably, it has a grouting bladder;

[0013] The grouting bag is located on the side of the anchor plate away from the grouting port. The grouting anchor passes through the grouting bag, and both ends of the grouting bag are sealed and fixed to the outer side wall of the grouting anchor. The grouting anchor wrapped by the grouting bag has a grout inlet hole.

[0014] The grouting anchor has a sealing ball inside. The sealing ball is located on the side of the grout inlet hole away from the grouting port, and there is no grouting hole between the sealing ball and the grout inlet hole. The sealing ball is used to prevent the air from flowing between the two sides of the sealing ball inside the grouting anchor. The sealing ball can move inside the grouting anchor under the action of force F.

[0015] Preferably, the irregular structure is made of steel sheet, and the irregular structure is a barbed structure, and satisfies the following conditions:

[0016] On the same irregular structure, there are points A and B. If the distance from point A to the grouting port is greater than the distance from point B to the grouting port, then the distance from point A to the anti-buoyancy anchor is greater than the distance from point B to the anti-buoyancy anchor.

[0017] The spacing between the irregular structures in the axial direction of the grouting anchor is 15cm-20cm. On the cross-section perpendicular to the axis of the grouting anchor, the three irregular structures are evenly distributed on the outer wall of the grouting anchor.

[0018] Preferably, the grouting holes are located on the side of the anchoring plate away from the grouting port, and the distance between the grouting holes and the grouting port is greater than the distance between the grouting holes and the grouting port, the grouting holes are spaced apart in the axial direction of the grouting anchor rod, and the grouting holes are uniformly distributed in the cross-sectional direction of the grouting hole, the diameter of the grouting hole is 1-2cm;

[0019] The anti-floating anchor rod is sealed away from the grouting port.

[0020] Preferably, the grouting holes are spaced apart in the axial direction of the grouting anchor rod, and satisfy,

[0021] D1<D2<...<Dn, D2-D1<D3-D2<...<Dn-D(n-1), wherein Dn represents the distance between the grouting hole and the grouting port in the axial direction of the grouting anchor rod, n is the total number of different distances between the grouting hole and the grouting port in the axial direction of the grouting anchor rod, and n is an integer greater than 3.

[0022] Preferably, the movable anchor rod is provided;

[0023] The movable anchor rod is a steel pipe, the pipe wall of the movable anchor rod is provided with a grouting hole, and the pipe wall of the movable anchor rod is fixedly connected with the special-shaped structure.

[0024] The end of the grouting anchor rod away from the grouting port is connected with the movable anchor rod through a connecting piece.

[0025] Preferably,

[0026] A plurality of movable anchor rods are provided, and the movable anchor rods are connected through connecting pieces, and the connecting pieces are trapezoidal thread connecting pieces.

[0027] A construction method of an existing building anti-floating anchor rod, comprising the structure of the existing building anti-floating anchor rod, characterized in that it comprises,

[0028] S1, grouting hole positioning: measuring the elevation of the site, determining the deformation position of the site, and performing line measurement according to the design requirements to determine the drilling position and the hole elevation, and marking on the ground;

[0029] S2, drilling: according to the site layout point, the drill bit is aligned with the center position of the drilling point, the verticality of the drill rod is ensured to be not more than 1%, and the drilling diameter and depth are not less than the design value;

[0030] S3, drilling flushing: after drilling to the specified depth, clean water is continuously pressed into the drilling hole to flush out the rock debris and gravel in the drilling hole, and the cracks around the drilling hole are flushed clean, and the duration of this process is not less than 10min;

[0031] S4, Grouting Anchor Bolt Fabrication: Determine the length and number of sections of the grouting anchor bolt according to the borehole diameter and depth, fabricate trapezoidal threaded connectors, drill grouting holes on the anchor bolt, cut irregular structures and weld the irregular structures onto the outer wall of the grouting anchor bolt;

[0032] S5, Grouting Bag Fabrication: Determine the position and length of the grouting bag based on the drilling depth and the thickness of the anti-seepage base plate. Drill multiple grouting holes at the location where the grouting anchor is wrapped by the bag. Wrap geotextile around the bag and seal both ends of the bag to the grouting anchor with sealing tape and fastening rings. Insert a sealing ball into the grouting anchor, with its depth exceeding the depth of the grouting hole.

[0033] S6, Anchor Plate Fabrication: The anchor plate is made of steel plate;

[0034] S7, Anchor bolt installation and grouting: The prepared grouting anchor bolt is lowered into the borehole, and the grouting anchor bolt is pressed into the specified depth using the borehole.

[0035] Prepare the first grouting liquid for bag grouting, and use a grouting pump to inject the first grouting liquid into the grouting anchor. When the cement grout initially sets, use high-pressure water to flush the grouting port of the grouting anchor to remove residual cement, and then wait for it to set for 1 day.

[0036] S8, seepage prevention and anchoring grouting: The second grouting liquid is prepared using cement, water-reducing agent, quick-setting agent, etc. Static pressure grouting and intermittent grouting are carried out through the grouting port of the grouting anchor using a grouting pump until a sudden increase in grouting liquid occurs and remains stable. The grouting volume is reduced and the grouting pressure change is observed. When the pressure continues to rise, grouting can be terminated and the orifice sealed. It is allowed to set for more than 7 days.

[0037] S9, Installation of anchor plate and application of prestress: When the strength of the grouting anti-seepage structure and the anchor body reaches the design value, apply prestress to the anchor rod body after installing the anchor plate to tension the anchor rod.

[0038] The maximum tensile force is 0.5 times the destructive force. The tensioning is carried out in 5 stages, and the tensioning process is kept at a constant speed. When each load level is reached, it is maintained for 5-10 minutes, and the surface deformation is detected.

[0039] S10, Fill and seal the anchor plate: Use cement mortar to fill the anchor pit so that it is level with the original ground surface.

[0040] Preferably, the anchor plate is not less than 10mm thick, the anchor plate is not less than 300mm wide, the width of the anchor pit is 30mm-40mm wider than the width of the anchor plate, and the depth of the anchor pit is 10mm greater than the thickness of the anchor plate.

[0041] The grouting anchor rod is a seamless steel pipe, the diameter of the grouting anchor rod is not less than 50 mm, the wall thickness of the grouting anchor rod is not less than 5 mm, and the length of the grouting anchor rod is 10 cm longer than the drilling depth;

[0042] The length of the grouting bag is 20 cm-40 cm, and the height of the sealed end of the grouting bag and the grouting anchor rod is lower than the height of the lowest point of the anti-seepage floor.

[0043] Preferably, in S7, the water-cement ratio of the first grouting liquid is 0.6, and the pressure of the bag grouting causes the sealing rubber ball to be immovable.

[0044] Preferably, in S8, the water-cement ratio of the first grouting liquid is 0.6-1.0, and the water-reducing agent, accelerator and the like in the admixture are all percentages of the weight of cement.

[0045] The beneficial effects of the present application are embodied in providing a kind of existing building anti-floating anchor rod structure and construction method.

[0046] (1) Compared with the traditional anti-floating structure, the present application combines grouting reinforcement with anti-floating anchor rod, and utilizes the self-weight of the geological structure to resist the buoyancy generated by groundwater.

[0047] (2) The present application overcomes the deformation of the bottom plate caused by the thin anti-water bottom plate, and simultaneously realizes the thickening of the waterproof bottom plate by using grouting reinforcement in the opposite direction, thereby providing structural support for the application of anchor rod prestress.

[0048] (3) Compared with the traditional anti-floating anchor rod, the present application realizes structural resistance, solves the problem of anti-floating structure not being able to prevent seepage, and avoids the structural damage caused by groundwater seepage. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 It is a kind of existing building anti-floating anchor rod structure schematic diagram;

[0050] Figure 2 It is a kind of grouting anchor rod structure schematic diagram;

[0051] Figure 3 It is a kind of special-shaped structure schematic diagram;

[0052] Figure 4 It is a kind of grouting bag and grouting anchor rod section view;

[0053] Figure 5 It is a kind of existing building anti-floating anchor rod construction method flow chart.

[0054] BRIEF DESCRIPTION OF DRAWINGS

[0055] Grouting anchor rod 1, anchor plate 2, locking structure 3, grouting bag 4, special-shaped structure 5, trapezoidal thread connecting piece 6, anti-seepage bottom plate 7;

[0056] Slurry inlet hole 101, slurry injection hole 102;

[0057] Fastening ring 402, sealing tape 403. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0059] Please refer to Figures 1-5 The specific embodiments provided by the present application are as follows:

[0060] Embodiment 1:

[0061] This embodiment refers to Figures 1-4 As shown in the figure, an anti-floating anchor rod structure for existing building, characterized in that, comprising,

[0062] Slurry injection anchor rod 1, anchor plate 2, locking structure 3;

[0063] Among them, the slurry injection anchor rod 1 is a steel pipe, one open end of the slurry injection anchor rod 1 is a slurry injection port, the steel pipe wall is provided with a slurry injection hole 102 and a slurry inlet hole 101, and the steel pipe wall is fixedly connected with the special-shaped knot 5;

[0064] Among them, the anchor plate 2 has a through hole at the center position, the slurry injection anchor rod 1 passes through the through hole, the axis of the through hole coincides with the axis of the slurry injection anchor rod 1, and the distance between the anchor plate 2 and the slurry injection port is 10-20 cm;

[0065] Among them, the locking structure 3 is located on the side of the anchor plate 2 facing the slurry injection port, and the locking structure 3 is used to prevent the slurry injection anchor rod 1 from moving with the anchor plate 2.

[0066] With a slurry injection bag 4;

[0067] Among them, the slurry injection bag 4 is located on the side of the anchor plate 2 away from the slurry injection port, the slurry injection anchor rod 1 passes through the slurry injection bag 4, and the two ends of the slurry injection bag 4 are respectively sealed and fixed on the outer side wall of the slurry injection anchor rod 1, and the slurry injection anchor rod 1 position wrapped by the slurry injection bag 4 has a slurry inlet hole 101;

[0068] The slurry injection anchor rod 1 has a sealing rubber ball inside, the sealing rubber ball is located on the side of the slurry inlet hole 101 away from the slurry injection port, and there is no slurry injection hole 102 between the sealing rubber ball and the slurry inlet hole 101, the sealing rubber ball is used to prevent the air on both sides of the sealing rubber ball inside the slurry injection anchor rod 1 from flowing, and the sealing rubber ball can move inside the slurry injection anchor rod 1 under the action of force F.

[0069] For the existing building which has been inhabited for many years, due to the rainy season or heavy rain and other reasons, the groundwater level of the existing building is higher than the anti-floating water level, the waterproof floor of the building structure is uplifted, cracked, partially damaged or floated as a whole, the basement floor is flooded, and even the structure is damaged, which affects the safe use and operation of the building structure. Therefore, in order to effectively cope with the adverse effects caused by the rising of groundwater level on the building structure, the design and implementation of the anti-floating structure are crucial.

[0070] In the embodiment, as shown in Figures 1-4 The existing building anti-floating anchor rod structure is characterized by comprising a grouting anchor rod 1, an anchoring plate 2, and a locking structure 3. The grouting anchor rod 1 is a steel pipe, one open end of the grouting anchor rod 1 is a grouting port, the steel pipe wall is provided with a grouting hole 102 and a grouting inlet hole 101, and the steel pipe wall is fixedly connected with a special-shaped structure 5. The grouting port is used for pouring anti-floating grouting slurry, the grouting slurry flows in the steel pipe from the grouting port, and the grouting slurry flows out of the steel pipe through the grouting hole 102 and the grouting inlet hole 101. The anchoring plate 2 has a through hole at the center position, the grouting anchor rod 1 penetrates the through hole, the axis of the through hole coincides with the axis of the grouting anchor rod 1, and the distance between the anchoring plate 2 and the grouting port is 10-20 cm. The locking structure 3 is located on the side of the anchoring plate 2 facing the grouting port, and the locking structure 3 is used to prevent the grouting anchor rod 1 from moving with the anchoring plate 2. There is a grouting bag 4. The grouting bag 4 is located on the side of the anchoring plate 2 away from the grouting port, the grouting anchor rod 1 penetrates the grouting bag 4, and the two ends of the grouting bag 4 are respectively sealed and fixed on the outer side wall of the grouting anchor rod 1. The grouting anchor rod 1 position wrapped by the grouting bag 4 has a grouting inlet hole 101. The grouting anchor rod 1 has a sealing rubber ball inside, the sealing rubber ball is located on the side of the grouting inlet hole 101 away from the grouting port, and there is no grouting hole 102 between the sealing rubber ball and the grouting inlet hole 101. The sealing rubber ball is used to prevent the air on both sides of the sealing rubber ball inside the grouting anchor rod 1 from flowing, and the sealing rubber ball can move inside the grouting anchor rod 1 under the action of force F. The grouting bag 4 is made of geotextile, which not only has good water permeability, but also has sufficient strength and elongation. When grouting the grouting bag 4, the sealing rubber ball is located inside the grouting anchor rod 1, the sealing rubber ball is located between the grouting inlet hole 101 and the grouting hole 102, the grouting slurry can only enter the inside of the grouting bag 4 through the grouting inlet hole 101, and until it cannot continue to enter the bag, it indicates that the bag grouting is complete. The bag is used to seal with the impermeable floor to provide a static pressure grouting environment for anchoring grouting.

[0071] Embodiment 2:

[0072] This embodiment refers to Figure 3As shown in the drawings, wherein (a) represents a side view of the special-shaped structure, (b) represents a top view of the special-shaped structure, the special-shaped structure 5 is made of a steel sheet, the special-shaped structure 5 is a barb structure, and satisfies,

[0073] The same special-shaped structure 5 has an A point and a B point, if the distance from the A point to the grouting port is greater than the distance from the B point to the grouting port, the distance from the A point to the anti-floating anchor rod is greater than the distance from the B point to the anti-floating anchor rod;

[0074] The interval of the special-shaped structure 5 in the axial direction of the grouting anchor rod 1 is 15-20 cm, and in the cross section perpendicular to the axis of the grouting anchor rod 1, the three special-shaped structures 5 are uniformly distributed on the outer wall of the grouting anchor rod 1.

[0075] In the embodiment, the special-shaped structure 5 is made of a steel sheet, the special-shaped structure 5 is a barb structure, and satisfies, the same special-shaped structure 5 has an A point and a B point, if the distance from the A point to the grouting port is greater than the distance from the B point to the grouting port, the distance from the A point to the anti-floating anchor rod is greater than the distance from the B point to the anti-floating anchor rod; the interval of the special-shaped structure 5 in the axial direction of the grouting anchor rod 1 is 15-20 cm, and in the cross section perpendicular to the axis of the grouting anchor rod 1, the three special-shaped structures 5 are uniformly distributed on the outer wall of the grouting anchor rod 1. By welding the barb-shaped special-shaped structure 5 on the grouting anchor rod 1, the contact area of the grouting anchor rod 1 and the anti-seepage reinforced body after the grouting slurry solidifies can be increased, the friction force between the grouting anchor rod 1 and the anti-seepage reinforced body can be increased, and thus the pull-out resistance of the anti-floating anchor rod structure can be improved.

[0076] Embodiment 3:

[0077] The grouting hole 102 is located on the side of the anchoring plate 2 away from the grouting port, and the distance between the grouting hole 102 and the grouting port is greater than the distance between the grouting hole 101 and the grouting port, the interval of the grouting hole 102 in the axial direction of the grouting anchor rod 1 is 15-20 cm, and in the cross section direction of the grouting hole 102, three grouting holes 102 are uniformly distributed, and the diameter of the grouting hole 102 is 1-2 cm;

[0078] The end of the anti-floating anchor rod away from the grouting port is sealed.

[0079] In the embodiment, the grouting holes 102 are located on the side of the anchoring plate 2 away from the grouting port, and the distance between the grouting holes 102 and the grouting port is greater than the distance between the grouting inlet 101 and the grouting port. The distance between the grouting holes 102 in the axial direction of the grouting anchor 1 is 15-20 cm, and three grouting holes 102 are uniformly distributed in the cross-sectional direction of the grouting hole 102. The diameter of the grouting hole 102 is 1-2 cm. For the same static pressure grouting, the end of the anti-floating anchor away from the grouting port is sealed, which can make more grouting slurry diffuse towards the side of the grouting anchor 1, thereby forming a larger volume of anti-permeation reinforcement on the side of the grouting anchor 1, and improving the anti-permeation ability of the building group.

[0080] Embodiment 4:

[0081] The grouting holes 102 are spaced apart in the axial direction of the grouting anchor 1, and satisfy,

[0082] D1 < D2 <... < Dn, D2-D1 < D3-D2 <... < Dn-D(n-1), wherein Dn represents the distance between the grouting hole 102 and the grouting port in the axial direction of the grouting anchor 1, n is the total number of different distances between the grouting hole 102 and the grouting port in the axial direction of the grouting anchor 1, and n is an integer greater than 3.

[0083] In the embodiment, when static pressure grouting or intermittent grouting is performed, the farther the distance from the grouting port, the greater the pressure difference between the inside and outside of the grouting hole 102, and the more easily the grouting slurry diffuses from the inside to the outside of the grouting hole 102, thereby more easily penetrating into the sand and gravel layer. When the grouting holes 102 have the same spacing, the speed of slurry diffusion into sand and gravel at the deep grouting hole 102 is greater than that at the shallow grouting hole 102 during grouting. At this time, the sand and gravel around the deep grouting hole 102 is first penetrated to the preset range, and the sand and gravel around the shallow grouting hole 102 has not been penetrated to the preset range. At this time, the penetrated sand and gravel around the shallow grouting hole 102 begins to solidify, and the sand and gravel around the shallow grouting hole 102 cannot be penetrated to the preset range. Thus, the anti-floating effect and anti-permeation function of the anti-floating anchor are affected.

[0084] In the embodiment, the grouting holes 102 are spaced apart in the axial direction of the grouting anchor rod 1, and satisfy D1 < D2 <... < Dn, D2-D1 < D3-D2 <... < Dn-D(n-1), where Dn represents the distance between the grouting hole 102 and the grouting port in the axial direction of the grouting anchor rod 1, n is the total number of different distances between the grouting hole 102 and the grouting port in the axial direction of the grouting anchor rod 1, and n is an integer greater than 3. By adjusting the spacing of the grouting holes 102 in the axial direction of the grouting anchor rod 1, the speed of the grout spreading into the sand and pebbles at the grouting hole 102 with a large depth is reduced compared to the speed of the grout spreading into the sand and pebbles at the grouting hole 102 with a small depth, so that the time difference between the time taken for the grout to penetrate to the preset range at the grouting hole 102 with a large depth and the time taken for the grout to penetrate to the preset range at the grouting hole 102 with a small depth is smaller, thereby ensuring that the volume of the anti-seepage reinforced body formed reaches the preset value, and the anti-seepage area reaches the preset area.

[0085] Embodiment 5:

[0086] 6. The anti-floating anchor rod structure for an existing building according to claim 3, characterized in that

[0087] has a movable anchor rod;

[0088] wherein the movable anchor rod is a steel pipe, the pipe wall of the movable anchor rod is provided with grouting holes 102, and the pipe wall of the movable anchor rod is fixedly connected with the special-shaped structure 5;

[0089] one end of the grouting anchor rod 1 away from the grouting port is connected with the movable anchor rod through a connecting piece.

[0090] For the characteristics of the existing building itself, the length of the anchor rod is often limited by the basement space in the anti-floating reinforcement project of the existing basement structure, and the conventional anti-floating anchor rod needs to be welded and constructed in sections, and the lengths of the anti-floating anchor rods required at different positions are different, and it is low in efficiency to manufacture each kind of anti-floating anchor rod separately.

[0091] In the embodiment, the movable anchor rod is provided, wherein the movable anchor rod is a steel pipe, the pipe wall of the movable anchor rod is provided with grouting holes 102, and the pipe wall of the movable anchor rod is fixedly connected with the special-shaped structure 5; one end of the grouting anchor rod 1 away from the grouting port is connected with the movable anchor rod through a connecting piece. There are a plurality of movable anchor rods, and the movable anchor rods are connected with each other through connecting pieces, and the connecting pieces are trapezoidal threaded connecting pieces 6. For the grouting anchor rods 1 that are only different in length, the grouting anchor rods 1 with a unified standard and the same length can be set as first grouting anchor rods 1, the first grouting anchor rods 1 are mass-produced, the movable anchor rods are cut on site to have different lengths, and then the movable anchor rods are welded or connected with the first grouting anchor rods 1 to become the anti-floating anchor rods required for the final construction. The present application can save the time for on-site manufacturing of the anti-floating anchor rods and improve the construction efficiency.

[0092] Embodiment 6:

[0093] The plurality of movable anchor rods are connected by a connecting piece, which is a trapezoidal thread connecting piece 66.

[0094] In the embodiment, for the anti-floating anchor rod with a large length, a plurality of movable anchor rods are connected to work together, the grouting anchor rod 1 and the movable anchor rod are connected by threads, if the threads at the connecting position are loose, due to the change of the underground water floating force, the anchoring body is easily pulled and broken, and the anti-floating structure loses the tensile capacity, and the building structure also loses the protection of the anti-floating function. Therefore, the movable anchor rod and the movable anchor rod are connected by a connecting piece, which is a trapezoidal thread connecting piece 6. The trapezoidal thread connecting piece 6 has high tooth root strength and is not easy to be damaged, and can increase the service life of the anchoring body.

[0095] Embodiment 7:

[0096] The embodiment refers to Figure 5 The anti-floating anchor rod construction method for the existing building, comprising the anti-floating anchor rod structure for the existing building, characterized by comprising,

[0097] S1, grouting anchor hole positioning: measuring the elevation of the site, determining the deformation position of the site, and performing line measurement according to the design requirements, determining the hole position and the hole elevation, and marking on the ground;

[0098] S2, drilling: according to the site layout point, the drill bit of the drilling machine is aligned with the center position of the drilling point, the verticality of the drill rod is ensured to be not more than 1%, and the drilling diameter and depth are not less than the design value;

[0099] S3, drilling flushing: after drilling to the specified depth, clean water is continuously pressed into the drilling hole to flush out the rock debris and gravel in the drilling hole, and the cracks around the drilling hole are flushed clean, and the duration of this process is not less than 10 min;

[0100] S4, grouting anchor rod 1 manufacturing: according to the drilling diameter and depth, the length and the number of nodes of the grouting anchor rod 1 are determined, the trapezoidal thread connecting piece 6 is manufactured, the grouting hole 102 is drilled on the anchor rod, the special-shaped structure 5 is cut and welded on the outer pipe wall of the grouting anchor rod 1;

[0101] S5, grouting bag 4 manufacturing: according to the drilling depth and the thickness of the anti-seepage bottom plate 7, the position and the bag length of the grouting bag 4 are determined, a plurality of grouting holes 101 are drilled at the position where the grouting anchor rod 1 is wrapped by the bag, the bag position is wrapped with geotextile, and the two ends of the bag are sealed and fastened on the grouting anchor rod 1 by the sealing tape 403 and the fastening ring 402, and the sealing rubber ball is lowered into the grouting anchor rod 1, and the depth should exceed the depth of the grouting hole 101;

[0102] S6, Anchor Plate 2 Fabrication: Anchor Plate 2 is made of steel plate;

[0103] S7, Anchor bolt installation and bag grouting: The prepared grouting anchor bolt 1 is lowered into the borehole, and the grouting anchor bolt 1 is pressed into the specified depth using the borehole;

[0104] Prepare the first grouting liquid for bag grouting, and use a grouting pump to inject the first grouting liquid into the grouting anchor 1. When the cement grout initially sets, use high-pressure water to flush the grouting port of the grouting anchor 1 to remove residual cement, and then wait for it to set for 1 day.

[0105] S8, seepage prevention and anchoring grouting: The second grouting liquid is prepared using cement, water-reducing agent, quick-setting agent, etc. Static pressure grouting and intermittent grouting are carried out through the grouting port of grouting anchor 1 using a grouting pump until a sudden increase in grouting liquid occurs and remains stable. The grouting volume is reduced and the grouting pressure change is observed. When the pressure continues to rise, grouting can be terminated and the orifice is sealed. It is allowed to set for more than 7 days.

[0106] S9, Install anchor plate 2 and apply prestress: When the strength of the grouting anti-seepage structure and the anchor body reaches the design value, apply prestress to the anchor rod body after installing anchor plate 2 to tension the anchor rod.

[0107] The maximum tensile force is 0.5 times the destructive force. The tensioning is carried out in 5 stages, and the tensioning process is kept at a constant speed. When each load level is reached, it is maintained for 5-10 minutes, and the surface deformation is detected.

[0108] S10, Fill and seal anchor plate 2: Use cement mortar to fill the anchor pit so that it is level with the original ground surface.

[0109] The anchor plate 2 has a thickness of not less than 10mm, a width of not less than 300mm, a width of 30mm-40mm greater than the width of the anchor plate, and a depth of 10mm greater than the thickness of the anchor plate.

[0110] Grouting anchor 1 is a seamless steel pipe with a diameter of not less than 50mm, a wall thickness of not less than 5mm, and a length 10cm longer than the drilling depth.

[0111] The length of the grouting bag 4 is 20cm-40cm, and the height of the end of the grouting bag 4 that is sealed with the grouting anchor rod 1 is lower than the height of the lowest point of the impermeable floor.

[0112] In the embodiment, the anchor plate 2 has a thickness of not less than 10 mm, a width of not less than 300 mm, a width of the anchor pit being 30-40 mm more than that of the anchor plate, and a depth of the anchor pit being 10 mm more than the thickness of the anchor plate; the grouting anchor rod 1 is a seamless steel pipe, has a diameter of not less than 50 mm, a wall thickness of not less than 5 mm, and a length of 10 cm more than the drilling depth; the grouting anchor rod 1 is convenient for sealing after grouting. The length of the grouting bag 4 is 20-40 cm, and the height of the sealed end of the grouting bag 4 and the grouting anchor rod 1 is lower than the height of the lowest point of the anti-seepage floor. After the grouting bag 4 is fully inflated, the diameter thereof should be 1.2-1.5 times of the drilling diameter. The edge of the grouting bag 4 in contact with the anti-seepage floor is extruded, so that the outer edge of the grouting bag 4 is sealed with the anti-seepage floor. Since the anti-seepage floor is not easy to deform, the grouting bag 4 is easy to move relative to the anti-seepage floor during grouting, so that the grouting bag 4 loses the sealing effect. In the embodiment, the height of the sealed end of the grouting bag 4 and the grouting anchor rod 1 is lower than the height of the lowest point of the anti-seepage floor. After the grouting bag 4 is inflated, the bottom of the grouting bag 4 has more contact area with the anti-seepage floor, which greatly relieves the problem of movement of the grouting bag 4 and provides conditions for the pressure environment of grouting.

[0113] Embodiment 8:

[0114] In S7, the water-cement ratio of the first grouting liquid is 0.6, and the pressure of the bag grouting makes the sealing rubber ball not move.

[0115] In S8, the water-cement ratio of the first grouting liquid is 0.6-1.0, and the water-reducing agent, accelerator and the like in the admixture are all percentages of the weight of cement.

[0116] In the embodiment, the following steps are included:

[0117] Step one: drilling hole by a drilling machine;

[0118] According to the design drawing, the drilling position is laid out by a total station, the drilling machine is erected, the vertical deviation of the drilling machine is less than 1%, the drilling diameter is not less than 180 mm, and the thickness of the anti-floating anchor rod anchoring body is not less than 50 mm.

[0119] The new anti-floating anchor rod is located between four columns of the building structure, and the drilling hole spacing is 1.5-2.5 m.

[0120] After the drilling is completed, the drilling hole is flushed by a drilling rod and clean water, and the flushing time is 10 min.

[0121] Step two: manufacturing the grouting anchor rod 1;

[0122] According to the drilling depth, a hollow seamless steel pipe with a diameter of 50 mm is used as the grouting anchor rod 1, and the single length of the grouting anchor rod 1 is 3 m; the lowest end is a sealing structure, and the top end is provided with a trapezoidal thread for connecting the next anchor rod. A grouting hole 102 is drilled vertically at an interval of 20 cm on the grouting anchor rod 1, and the diameter is 15 mm; and a special-shaped structure 5 is welded.

[0123] According to the thickness of the anti-seepage bottom plate 7, the anti-floating anchor rod is higher than the ground surface by 10 cm, a grouting bag 4 with a diameter of 20 cm is drilled at a distance of 20 cm-30 cm from the top end, and the grouting bag 4 is tied, and a sealing rubber ball is lowered into the anti-floating anchor rod.

[0124] Step three: drilling and implanting the grouting anchor rod 1 and once-bag grouting

[0125] The grouting anchor rod 1 is lowered into the hole, and the drill is pressed into the bottom of the hole. After one section is lowered, the second section of the anchor rod is connected by using the trapezoidal thread, and the connection is reinforced by electric welding.

[0126] The first grouting liquid is prepared as a micro-expanding cement grout with a water-cement ratio of 0.6. The first grouting liquid is injected along the grouting port by using a grouting pump to make the grouting bag 4 expand, realize the sealing of the hole, and then wait for 1 d.

[0127] Step four: anti-seepage and anchoring grouting

[0128] The second grouting liquid is prepared as an anti-seepage anchoring grout by using cement, polycarboxylic acid water reducing agent, water glass and modified fiber. The water-cement ratio is 0.6, the polycarboxylic acid water reducing agent is 0.3%, the water glass and the cement slurry are in a volume ratio of 1:1, and the modified fiber is added in an amount of 1.5% of the mass of the cement.

[0129] Start grouting, and record the change of grouting pressure and the deformation of the ground surface during the grouting process. The grouting pressure is generally not more than 0.5 MPa to prevent the independent foundation from being lifted. After the grouting is completed, wait for 7 d.

[0130] Step five: tensioning and anchoring

[0131] According to the previous destructive tensioning test, the failure anchoring force of the 6 m-7 m long anchor rod is 12 t. Therefore, the maximum design tensioning force is 8 t when the production tensioning is carried out. After the anchoring plate 2 is installed, the tensioning is carried out in 5 stages.

[0132] Example 9:

[0133] Step one: drill hole;

[0134] According to the design drawing, the total station instrument is used to arrange the drilling position, the drill is erected, the vertical deviation of the drill is less than 1%, the drilling diameter is not less than 180 mm, and the thickness of the anti-floating anchor rod anchoring body is not less than 50 mm.

[0135] The new anti-floating anchor rod is located between the four columns of the building structure, with a drilling interval of 4 m, and an anti-seepage grouting hole 102 is arranged between the two anchor holes.

[0136] After drilling, the drill rod and clean water are used to flush the drill hole, and the flushing time is 10 min.

[0137] Step two: production of grouting anchor rod 1

[0138] According to the drilling depth, a hollow seamless steel pipe with a diameter of 50 mm is used as the grouting anchor rod 1, and the single length of the grouting anchor rod 1 is 3 m; the lowest end is a sealing structure, and the top end is provided with a trapezoidal thread for connecting the lower anchor rod. The grouting hole 102 is drilled vertically at an interval of 20 cm, with a diameter of 15 mm; and the special-shaped structure 5 is welded.

[0139] According to the thickness of the anti-seepage bottom plate 7, which is 20 cm, the anchor rod is higher than the ground surface by 10 cm, and a diameter of 20 cm is drilled between 20 cm-30 cm from the top end. The bag grout inlet is tied and the sealing rubber ball is lowered.

[0140] Step three: drilling and implanting grouting anchor rod 1 and one bag grouting

[0141] The anchor rod is lowered into the hole, and the drill is pressed into the bottom of the hole. After one section is lowered, the second section is used with the trapezoidal thread, and the connection is reinforced and connected by electric welding.

[0142] The first grouting liquid is prepared as a micro-expanding cement grout with a water-cement ratio of 0.6, which is injected along the grouting pipe using a grouting pump to make the grouting bag 4 expand, realize the sealing of the hole, and then wait for 1 d.

[0143] Step four: anti-seepage and anchoring grouting

[0144] The second grouting liquid is prepared as an anti-seepage anchoring grout using cement, polycarboxylic acid water reducing agent, water glass and modified fiber, with a water-cement ratio of 0.6, a polycarboxylic acid water reducing agent of 0.3%, a water glass to cement volume ratio of 1:1, and a modified fiber addition of 1.5% of the cement mass.

[0145] Start grouting, record the change of grouting pressure and ground deformation during grouting, the grouting pressure generally does not exceed 0.5 MPa, to prevent the independent foundation from lifting, and wait for 7 d after grouting is completed.

[0146] The anti-seepage grouting adopts pure pressure grouting with hole closure, and the design grouting volume per unit length is 0.8 m3.

[0147] Step five: tensioning and anchoring

[0148] According to the previous destructive tensioning test, the failure anchoring force of the 6m-7m long anchor rod is 12t. Therefore, the maximum design tensioning force is 8t during production tensioning. After installing the anchoring plate 2, tensioning is carried out in 5 stages.

[0149] In the description of the embodiments of the present application, it needs to be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "center", "top", "bottom", "top", "bottom", "inner", "outer", "inner side", "outer side" and the like indicate the orientation or positional relationship.

[0150] In the description of the embodiments of the present application, it needs to be understood that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "assembling" should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0151] In the description of the embodiments of the present application, specific features, structures, materials or characteristics can be combined in any one or more embodiments or examples in a suitable manner.

[0152] In the description of the embodiments of the present application, it needs to be understood that "-" and "~" represent the range of the same of two numerical values, and the range includes the end points. For example: "A-B" represents the range of greater than or equal to A and less than or equal to B. "A~B" represents the range of greater than or equal to A and less than or equal to B.

[0153] In the description of the embodiments of the present application, the term "and / or" herein is only a description of the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " herein generally represents that the front and rear associated objects are a kind of "or" relationship. Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. An anti-buoyancy anchor structure for existing buildings, characterized in that, including, grouting anchor rods, anchoring plates, and locking structures; wherein, the grouting anchor rod is a steel pipe, one open end of the grouting anchor rod is a grouting port, the steel pipe wall is provided with grouting holes and slurry inlet holes, and the steel pipe wall is fixedly connected to a special-shaped structure; wherein, a through hole is provided at the center position of the anchoring plate, the grouting anchor rod passes through the through hole, the axis of the through hole coincides with the axis of the grouting anchor rod, and the distance between the anchoring plate and the grouting port is 10 cm - 20 cm; wherein, the locking structure is located on the side of the anchoring plate facing the grouting port, and the locking structure is used to prevent displacement between the grouting anchor rod and the anchoring plate; having a grouting bladder; wherein, the grouting bladder is located on the side of the anchoring plate背离注浆口 (should be 'opposite to the grouting port' in English), the grouting anchor rod passes through the grouting bladder, and both ends of the grouting bladder are respectively sealed and fixed on the outer wall of the grouting anchor rod, and a slurry inlet hole is provided at the position of the grouting anchor rod wrapped by the grouting bladder; a sealing rubber ball is provided inside the grouting anchor rod, the sealing rubber ball is located on the side of the slurry inlet hole背离注浆口 (should be 'opposite to the grouting port' in English), and there is no grouting hole between the sealing rubber ball and the slurry inlet hole. The sealing rubber ball is used to prevent the air circulation on both sides of the sealing rubber ball inside the grouting anchor rod, and the sealing rubber ball can move inside the grouting anchor rod under the action of force F.

2. The anti-floating anchor rod structure of an existing building according to claim 1, wherein the special-shaped structure is made of steel sheets, the special-shaped structure is a barbed structure, and satisfies there are points A and B on the same special-shaped structure. If the distance from point A to the grouting port is greater than the distance from point B to the grouting port, the distance between point A and the anti-floating anchor rod is greater than the distance between point B and the anti-floating anchor rod; in the axial direction of the grouting anchor rod, the spacing of the special-shaped structures is 15 cm - 20 cm, and in the cross-section perpendicular to the axis of the grouting anchor rod, 3 special-shaped structures are evenly distributed on the outer wall of the grouting anchor rod.

3. The anti-floating anchor rod structure of an existing building according to claim 2, wherein the grouting holes are located on the side of the anchoring plate背离注浆口 (should be 'opposite to the grouting port' in English), and the distance between the grouting holes and the grouting port is greater than the distance between the slurry inlet holes and the grouting port. In the axial direction of the grouting anchor rod, the spacing of the grouting holes is 15 cm - 20 cm, and 3 grouting holes are evenly distributed in the cross-section direction of the grouting holes, and the diameter of the grouting holes is 1 cm - 2 cm; one end of the anti-floating anchor rod背离注浆口 (should be 'opposite to the grouting port' in English) is sealed.

4. The anti-floating anchor rod structure of an existing building according to claim 3, wherein the spacing of the grouting holes in the axial direction of the grouting anchor rod is different, and satisfies D1 < D2 <... < Dn, D2 - D1 < D3 - D2 <... < Dn - D(n - 1), where Dn represents the distance between the grouting hole and the grouting port in the axial direction of the grouting anchor rod, and n is the total number of different distances between the grouting holes and the grouting port in the axial direction of the grouting anchor rod, and n is an integer greater than 3.

5. The anti-floating anchor rod structure of an existing building according to claim 2, wherein there is a movable anchor rod; wherein, the movable anchor rod is a steel pipe, the pipe wall of the movable anchor rod is provided with grouting holes, and the pipe wall of the movable anchor rod is fixedly connected to a special-shaped structure; one end of the grouting anchor rod背离注浆口 (should be 'opposite to the grouting port' in English) is connected to the movable anchor rod through a connecting piece.

6. The anti-floating anchor rod structure of an existing building according to claim 5, wherein It has multiple movable anchor bolts, which are connected to each other by a connector, which is a trapezoidal threaded connector.

7. A method for constructing anti-buoyancy anchors for existing buildings, comprising an anti-buoyancy anchor structure for existing buildings as described in any one of claims 1-6, characterized in that, include, S1, Grouting Anchor Hole Positioning: Measure the elevation of the site, determine the location of site deformation, and conduct line measurement according to design requirements to determine the drilling position and borehole elevation, and mark it on the ground; S2, Drilling: Based on the on-site layout points, align the drill bit of the drilling rig with the center of the drilling point, ensuring that the verticality of the drill rod does not exceed 1%, and that the drilling diameter and depth are not less than the design values; S3, Borehole flushing: After drilling to the specified depth, continuously press clean water into the borehole to flush out the rock cuttings and gravel, and clean the cracks around the borehole. This process should last for no less than 10 minutes. S4, Grouting Anchor Bolt Fabrication: Determine the length and number of sections of the grouting anchor bolt according to the borehole diameter and depth, fabricate trapezoidal threaded connectors, drill grouting holes on the anchor bolt, cut irregular structures and weld the irregular structures onto the outer wall of the grouting anchor bolt; S5, Grouting Bag Fabrication: Determine the position and length of the grouting bag based on the drilling depth and the thickness of the anti-seepage base plate. Drill multiple grouting holes at the location where the grouting anchor is wrapped by the bag. Wrap geotextile around the bag and seal both ends of the bag to the grouting anchor with sealing tape and fastening rings. Insert a sealing ball into the grouting anchor, with its depth exceeding the depth of the grouting hole. S6, Anchor Plate Fabrication: The anchor plate is made of steel plate; S7, Anchor bolt installation and bag grouting: The prepared grouting anchor bolt is lowered into the borehole, and the grouting anchor bolt is pressed into the specified depth using the borehole; Prepare the first grouting liquid for bag grouting, and use a grouting pump to inject the first grouting liquid into the grouting anchor. When the cement grout initially sets, use high-pressure water to flush the grouting port of the grouting anchor to remove residual cement, and then wait for it to set for 1 day. S8, seepage prevention and anchoring grouting: The second grouting liquid is prepared using cement, water-reducing agent and quick-setting agent. Static pressure grouting and intermittent grouting are carried out through the grouting port of the grouting anchor using a grouting pump until a sudden increase in grouting liquid occurs and remains stable. The grouting volume is reduced and the grouting pressure change is observed. When the pressure continues to rise, grouting can be terminated and the orifice is sealed. It is allowed to set for more than 7 days. S9, Installation of anchor plate and application of prestress: When the strength of the grouting anti-seepage structure and the anchor body reaches the design value, apply prestress to the anchor rod body after installing the anchor plate to tension the anchor rod. The maximum tensile force is 0.5 times the destructive force. The tensioning is carried out in 5 stages, and the tensioning process is kept at a constant speed. When each load level is reached, it is maintained for 5-10 minutes, and the surface deformation is detected. S10, Fill and seal the anchor plate: Use cement mortar to fill the anchor pit so that it is level with the original ground surface.

8. The construction method for anti-buoyancy anchor bolts in existing buildings according to claim 7, characterized in that, The anchor plate is not less than 10mm thick, the anchor plate is not less than 300mm wide, the width of the anchor pit is 30mm-40mm wider than the width of the anchor plate, and the depth of the anchor pit is 10mm greater than the thickness of the anchor plate. The grouting anchor is a seamless steel pipe with a diameter of not less than 50mm, a wall thickness of not less than 5mm, and a length 10cm longer than the drilling depth. The length of the grouting bag is 20cm-40cm, and the height of the end of the grouting bag that is sealed with the grouting anchor is lower than the height of the lowest point of the anti-seepage base plate.

9. A method for constructing anti-buoyancy anchors for existing buildings according to claim 8, characterized in that, In S7, the water-cement ratio of the first grouting liquid is 0.6, and the pressure of the grouting bag prevents the sealing ball from moving.

10. A method for constructing anti-buoyancy anchors for existing buildings according to claim 9, characterized in that, In S8, the water-cement ratio of the second grouting fluid is 0.6-1.0, and the water-reducing agent and quick-setting agent in the admixtures are both percentages of the cement weight.

Images