An anti-floating anchor rod structure for hard rock foundation pit construction

Abstract

The present invention belongs to the technical field of anti-floating anchor rods, and specifically relates to an anti-floating anchor rod structure used for foundation pit construction in hard rock formations. A structural grouting pipe, a threaded connecting rod movably arranged in the grouting pipe, an anchor head arranged at the lower end of the grouting pipe and detachably connected to the threaded connecting rod, a first ring body arranged on the outer peripheral side of the end of the grouting pipe close to the anchor head, a second ring body arranged on the outer peripheral side of the end of the anchor head close to the grouting pipe, and a supporting structure with two ends respectively hinged to the first ring body and the second ring body. The present invention separates the grouting pipe and the anchor head during grouting through the arrangement of the first ring body, the second ring body and the supporting structure, and the structure removed along with the grouting pipe can be recycled, which greatly reduces the economic cost and has the advantages of strong operability and good economy.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-floating anchor rods, and in particular relates to an anti-floating anchor rod structure used for hard rock stratum foundation pit construction. Background Art

[0002] With the rapid development of urban construction and the continuous increase in population in large and medium-sized cities, the demand for the rapid construction of high-rise buildings and underground spaces is increasing. The plane size of the basement is much larger than the main area above ground. The problem that follows is that the excavation depth of the foundation pit is getting deeper and deeper, and the burial depth of the foundation is increasing. In cities with abundant groundwater levels, especially coastal cities like Guangzhou, Shanghai, and Shenzhen, the basement water level is very high, and the rock layer is mostly sand. The basement will produce buoyancy on the structure buried in the soil. If the dead weight of the structure is less than the buoyancy, the bottom plate of the structure will arch and crack under the action of the buoyancy, and even the entire structure will float, causing the structure to be damaged, thus affecting its use. Therefore, the construction of anti-floating anchor rods is increasingly being used in engineering.

[0003] The construction process of anti-floating anchor rods in the prior art generally includes: an anchor head with a screw is drilled into a hole by a drill rod, a placement hole is opened on the screw anchor head, the drill rod enters the placement hole of the screw anchor head and is detachably connected, after the drill rod drills the screw to a predetermined hole depth, the steel bar passes through the drill rod into the placement hole and is connected to the screw anchor head, then the connector at the front end of the drill rod and the screw anchor head is detached, and while the drill rod is lifted upward, cement slurry is injected into the hole, and the grouting is completed.

[0004] The document with the authorization announcement number CN118327058B discloses an anti-floating anchor and its supporting structure, including a plurality of rod bodies that are detachably connected in sequence, the rod bodies are provided with a grouting channel for passing a grouting pipe, and the rod bodies are provided with a plurality of grouting holes connected to the grouting channel; the bottom end of the rod body connected to the drilled hole is connected with a connecting structure for strengthening the connection with the bearing layer, and the rod body connected to the top of the hole is provided with a supporting structure for supporting and limiting the rod body. Among them, the construction principle of strengthening the connection between the connecting structure and the bearing layer includes: when the anchor rod body enters the bottom of the hole, pressure is applied to the anchor rod body, driving the movable shaft and the anchor rod body to move relative to each other, and the connecting structure is unfolded, thereby expanding the hole-type limit with the bottom of the hole, increasing the tensile strength of the anti-floating anchor.

[0005] However, this solution still has the following problems: the connection structure is cast in the hole together with the anchor rod body, which consumes a lot of materials and has high economic cost.

[0006] To this end, the inventors have proposed an anti-floating anchor rod structure for hard rock foundation pit construction to solve the above-mentioned technical problems. Summary of the invention

[0007] In view of the above-mentioned problems, the purpose of the present invention is to provide an anti-floating anchor rod structure for hard rock foundation pit construction. Through the arrangement of the first ring body, the second ring body and the supporting structure, the grouting pipe and the anchor head are separated during grouting, and the structure removed along with the grouting pipe can be recycled, which greatly reduces the economic cost and has the advantages of strong operability and good economy.

[0008] The specific technical solutions of the present invention are as follows:

[0009] A floating-resistant anchor structure for hard rock foundation pit construction comprises a grouting pipe, a threaded connecting rod movably arranged in the grouting pipe, an anchor head arranged at the lower end of the grouting pipe and detachably connected to the threaded connecting rod, a first ring body arranged on the outer peripheral side of the end of the grouting pipe close to the anchor head, a second ring body arranged on the outer peripheral side of the end of the anchor head close to the grouting pipe, and a supporting structure with two ends hinged to the first ring body and the second ring body respectively; the second ring body comprises a second ring body main body, a limiting ring body fixedly arranged on the anchor head and located on a side of the second ring body away from the first ring body, and at least two clamping members hinged on the anchor head and used for clamping and fixing the second ring body; the supporting structure comprises at least a first rod body hinged to the first ring body and a second rod body hinged to the second ring body; the end of the first rod body away from the first ring body is hinged to the end of the second rod body away from the second ring body.

[0010] As a further preferred embodiment of the present invention, the clamping member includes a side groove arranged on the end of the anchor head, a fixing rod arranged between the groove walls on both sides of the side groove, a clamping plate having one end rotatably connected to the fixing rod and the other end extending radially along the anchor head to the outside of the anchor head, and a retaining piece arranged at the connection between the clamping plate and the side groove.

[0011] As a further preferred embodiment of the present invention, the retaining member includes a mounting opening arranged on the end of the clamping plate located in the side slot, and a torsion spring sleeved on the rod body of the fixing rod located at the mounting opening and connected to the side slot.

[0012] As a further preferred embodiment of the present invention, the number of the clamping members is 3 to 6, and they are distributed at intervals along the circumference of the anchor head.

[0013] As a further preferred embodiment of the present invention, a mounting block is provided at the end of the second rod body away from the second ring body, and the mounting block is provided with chisel teeth.

[0014] As a further preferred embodiment of the present invention, the first ring body includes a first ring body main body and two mounting protrusions which are arranged on the outer surface of the grouting pipe and are used to fix the position of the first ring body main body.

[0015] As a further preferred embodiment of the present invention, a spiral rib is arranged on the outer surface of the anchor head, and a threaded hole threadedly connected to the threaded connecting rod is arranged at the end of the anchor head.

[0016] As a further preferred embodiment of the present invention, a grouting channel is arranged in the grouting pipe, and a grouting hole communicating with the grouting channel is arranged on the pipe wall of the grouting pipe.

[0017] As a further preferred embodiment of the present invention, the grouting channel is provided with a reduced diameter section adapted to the threaded connecting rod near the anchor head.

[0018] As a further preferred embodiment of the present invention, the number of the supporting structures is 3 to 6.

[0019] The beneficial effects of the present invention are:

[0020] The anti-floating anchor rod structure provided by the present invention can separate the grouting pipe from the anchor head during grouting by arranging the first ring body, the second ring body and the supporting structure, and the structure removed with the grouting pipe can be recycled, which greatly reduces the economic cost.

[0021] The anti-floating anchor structure provided by the present invention strengthens the connection strength between the lower end of the anchor and the bottom surface and side walls of the channel through the arrangement of the first ring body, the second ring body and the supporting structure, and further improves the overall anti-floating performance of the anchor. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Attached Figure 1 It is a schematic diagram of the structure of the present invention at the main viewing angle.

[0023] Attached Figure 2 The structure diagram of the lower end of the anchor rod of the present invention is shown in FIG. Figure 1 .

[0024] Attached Figure 3 The structure diagram of the lower end of the anchor rod of the present invention is shown in FIG. Figure 2 .

[0025] Attached Figure 4 It is a schematic structural diagram of the supporting structure of the present invention when viewed from a side angle.

[0026] Attached Figure 5 It is a structural schematic diagram of the local schematic diagram A of the present invention.

[0027] Description of the drawings: grouting pipe 1, threaded connecting rod 2, anchor head 3, first ring body 4, second ring body 5, supporting structure 6;

[0028] Grouting channel 11, grouting hole 12, reduced diameter section 13;

[0029] Spiral ribs 31, threaded holes 32;

[0030] A first ring body 41 and a mounting protrusion 42;

[0031] A second ring body 51, a limiting ring body 52, and a clamping member 53;

[0032] Side slot 531, fixing rod 532, clamping plate 533, retaining member 534;

[0033] Mounting port 534a, torsion spring 534b;

[0034] A first rod body 61 and a second rod body 62;

[0035] Mounting block 621 and chisel teeth 622 . DETAILED DESCRIPTION

[0036] In the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the product of the invention is usually placed when in use, or are directions or positional relationships commonly understood by those skilled in the art. These directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0037] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms such as "setting" and "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection: it can be a mechanical connection or an electrical connection: it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] First of all, it should be pointed out that the anti-floating anchor rod structure described in the present invention is applied to foundation pit construction in hard rock areas. Hard rock refers to rock formations with a Pugh hardness coefficient f greater than or equal to 4, generally mixed metamorphic rocks. These rock formations have high hardness and are difficult to drill. Long drill rods are generally used for drilling. After the drilling and hole cleaning is completed, the anti-floating anchor rod provided by the present invention is hoisted into the hole and subsequently installed.

[0039] It is worth noting that the surface wall of the hole formed in the rock formation is relatively smooth, and the effect of using a structure supporting the hole wall to fix the anchor rod is not good due to factors such as slipping.

[0040] In addition, in actual construction scenarios, in order to ensure that the anchor rod is stable and does not tilt during grouting, a certain amount of gravel or other building materials are usually filled into the bottom of the hole before grouting to provide a certain support effect on the bottom of the anchor rod. However, the borehole itself has a small diameter, and building materials (usually excavated materials obtained by drilling) thrown in from above are easily stuck in the hole and cannot sink to the bottom of the hole, which not only fails to support the anchor rod, but also has an adverse effect on the fixed position of the anchor rod and the grouting quality.

[0041] Based on this, the present invention proposes an anti-floating anchor rod structure for hard rock foundation pit construction, and the following is a specific embodiment:

[0042] Reference Figure 1 ~Attached Figure 5 As shown, the present embodiment provides an anti-floating anchor rod structure for hard rock foundation pit construction, comprising a grouting pipe 1, a threaded connecting rod 2 movably arranged in the grouting pipe 1, an anchor head 3 arranged at the lower end of the grouting pipe 1 and detachably connected to the threaded connecting rod 2, a first ring body 4 arranged on the outer peripheral side of the end of the grouting pipe 1 close to the anchor head 3, a second ring body 5 arranged on the outer peripheral side of the end of the anchor head 3 close to the grouting pipe 1, and a supporting structure 6 having two ends hinged to the first ring body 4 and the second ring body 5 respectively.

[0043] It is understandable that a foundation base plate cushion layer is provided on the ground, a foundation base plate is provided on the top surface of the foundation base plate cushion layer, a perforation is provided on the top plate of the foundation base plate to allow the grouting pipe to pass through, and the grouting pipe also penetrates the foundation base plate cushion layer to enter the borehole, and a reinforcing plug ring is provided at the gap between the perforation of the foundation base plate cushion layer and the grouting pipe to reinforce the grouting pipe to ensure that the grouting pipe is centered and vertical. Furthermore, a ball bearing for reducing wear is provided between the reinforcing plug ring and the grouting pipe. In addition, a driving structure for lifting the grouting pipe and driving the threaded connecting rod to rotate is also provided on the foundation base plate. A plurality of positioning support structures for connecting to the borehole wall are distributed axially at intervals on the outer peripheral side of the grouting pipe 11 to fix the position of the grouting pipe, and the positioning support structure has a channel for fixing the grouting pipe for secondary grouting. The above structures are all known technologies to those skilled in the art, so they will not be described in detail.

[0044] In this embodiment, a grouting channel 11 is provided in the grouting pipe 1, and a grouting hole 12 connected to the grouting channel 11 is provided on the pipe wall of the grouting pipe 1, and a reduced diameter section 13 adapted to the threaded connecting rod 2 is provided near the anchor head 3. The grouting channel 11 runs through the entire grouting pipe, and the aperture of the grouting channel 11 needs to be larger than the diameter of the threaded connecting rod 2, preferably 1.2 to 1.5 times of the threaded connecting rod 2, so as to ensure the grouting rate and effect; the grouting holes 12 are distributed on the outer peripheral side of the grouting pipe 1 at a certain interval, and are inclined downward in the cross section to guide the flow direction of the slurry; the reduced diameter section 13 is slightly larger than the diameter of the threaded connecting rod 2 to ensure the smooth passage of the threaded connecting rod 2, preferably, a smooth sleeve is provided at the gap between the reduced diameter section 13 and the threaded connecting rod 2, and the smooth sleeve can be made of hard polytetrafluoroethylene, which not only strengthens the fixing effect of the threaded connecting rod 2, but also reduces the friction between the two. The above-mentioned slurry generally adopts cement mortar commonly used in the art, such as M15, M20, M25, M30, etc., which is obtained by mixing during on-site construction.

[0045] In this embodiment, a spiral rib 31 is provided on the outer surface of the anchor head 3, and a threaded hole 32 is provided at the end of the anchor head 3 to be threadedly connected to the threaded connecting rod 2. The lower end of the anchor head 3 is a pointed tip, which cooperates with the spiral rib 31 to strengthen the drilling ability of the anchor head 3; the threaded connection between the threaded connecting rod 2 and the threaded hole 32 ensures the connection strength between the threaded connecting rod 2 and the anchor head 3 while satisfying the detachable connection, and as the threaded connecting rod 2 is screwed in, the lower end of the grouting pipe 1 can also be driven close to the upper end of the anchor head 3, so that the injection position of the grouting pipe 1 is closer to the bottom of the hole.

[0046] In this embodiment, the first ring body 4 includes a first ring body 41 and two mounting protrusions 42 arranged on the outer surface of the grouting pipe 1 and used to fix the position of the first ring body 41. The first ring body 41 is sleeved outside the grouting pipe 1 and is fixed by the upper and lower mounting protrusions 42. Preferably, balls can be arranged on the inner ring surface and the upper and lower surfaces of the first ring body 41 to prevent the grouting pipe 1 from rotating under the drive of the threaded connecting rod 2, thereby driving the first ring body 41 to rotate; the mounting protrusions 42 are preferably ring bodies, which can be fixed to the grouting pipe 1 by bonding, welding, etc.

[0047] In this embodiment, the second ring body 5 includes a second ring body 51, a limiting ring body 52 fixedly arranged on the anchor head 3 and located on the side of the second ring body 51 away from the first ring body 4, and at least two clamping members 53 hinged on the anchor head 3 and used to clamp and fix the second ring body 51. Preferably, the number of the clamping members 53 is 3 to 6, and they are distributed at the same interval along the circumference of the anchor head 3. Among them, a resistance-enhancing layer for enhancing the friction effect between the second ring body 51 and the outer surface of the anchor head 3 is provided on the inner ring surface of the second ring body 51, which is used to ensure that the second ring body 5 can be driven to rotate synchronously when the anchor head 3 rotates. The material of the resistance-enhancing layer can be a material with a high friction coefficient such as rubber, or it can be achieved by processing the surface into a rough texture; the clamping member 53 can maintain a vertical state with the side wall of the anchor head 3 when there is no force applied in the axial direction, so as to cooperate with the limiting ring body 52 to fix the second ring body 51 from the upper and lower directions.

[0048] In this embodiment, the number of the support structures 6 is 3 to 6, which are distributed along the circumference at the same interval. They are preferably staggered with the clamping member 53 in a top view to avoid mutual influence between the two. The support structure 6 includes at least a first rod 61 hinged to the first ring body 4 and a second rod 62 hinged to the second ring body 5; the end of the first rod 61 away from the first ring body 4 is hinged to the end of the second rod 62 away from the second ring body 5. The connection between the first rod 61 and the second rod 62, as well as the connection between the first rod 61 and the second rod 62 respectively with the first ring body 4 and the second ring body 5 are all hinged, and the structure for realizing the hinge can directly adopt the commonly used structure in the field. Multiple support structures 6 constitute a skeleton structure similar to an "umbrella". When the grouting pipe 1 moves downward, the connection angle between the first rod 61 and the second rod 62 changes, so that the "umbrella" structure is unfolded, so that the connection between the first rod 61 and the second rod 62 is first abutted against the wall of the borehole. At this time, if the height of the grouting pipe 1 is controlled to remain unchanged, the unfolding state of the "umbrella" mechanism can be ensured to remain unchanged. The unfolded structure is helpful to fix the position of the lower end of the anchor rod, and reduce the influence of the vibration generated when the anchor rod 3 rotates driven by the threaded connecting rod 2 on the anchor rod.

[0049] In this embodiment, the clamping member 53 includes a side slot 531 disposed on the end of the anchor head 3, a fixing rod 532 disposed between the groove walls on both sides of the side slot 531, a clamping plate 533 having one end rotatably connected to the fixing rod 532 and the other end extending radially along the anchor head 3 to the outside of the anchor head 3, and a retaining member 534 disposed at the connection between the clamping plate 533 and the side slot 531. Further preferably, the retaining member 534 includes a mounting opening 534a disposed on the end of the clamping plate 533 located in the side slot 531, and a torsion spring 534b sleeved on the rod body of the fixing rod 532 located at the mounting opening 534a and connected to the side slot 531. Among them, the side groove 531 is located at the side end of the upper surface of the anchor head 3, that is, the side groove 531 has an upper opening and a side opening to ensure the smooth rotation of the clamping plate 533; the lower surface of the clamping plate 533 is as close to the lower bottom surface of the side groove 531 as possible to reduce the downward displacement range of the clamping plate 533; the torsion spring 534b can help to keep the clamping plate 533 perpendicular to the side wall of the anchor head 3. When the clamping plate 533 is subjected to an axial upward force, the clamping plate 533 overcomes the force of the torsion spring 534b and then changes from an angle perpendicular to the side wall of the shaft head 3 to an angle parallel to the side wall of the shaft head 3. The clamping force on the upper end of the second ring body 51 disappears. At this time, as the grouting pipe 1 rises, the support structure 6 drives the second ring body 51 to lift and detach from the anchor head 3, thereby achieving a recycling effect.

[0050] In this embodiment, a mounting block 621 is provided at the end of the second rod body 62 away from the second ring body 5, and a chisel tooth 622 is provided on the mounting block 621. After the chisel tooth 622 abuts against the borehole wall, it can cut the borehole wall as the anchor head 3 rotates, thereby processing an annular groove on the borehole wall, and the waste chiseled by the chisel tooth will directly fall on the bottom surface of the borehole to supplement the thickness of the gravel layer on the bottom surface, and after the grouting is completed, the slurry filled in the annular groove further strengthens the connection strength between the lower end of the anchor rod and the borehole, thereby improving the anti-floating performance of the anchor rod.

[0051] The anti-floating anchor rod structure provided in this embodiment has the following working principles: after the hole is drilled and cleaned, the foundation base plate cushion layer and the foundation base plate are constructed on the ground, the first ring body and the second ring body are respectively connected to the grouting pipe and the anchor head, the threaded connecting rod is screwed into the threaded channel on the anchor head, and the screwing depth of the threaded connecting rod is controlled to ensure that the support structure is in a contracted state. The grouting pipe with the positioning support structure installed on the surface drives the anchor head to be put into the drill hole together until the anchor head abuts against the bottom surface of the hole. Then the threaded connecting rod is rotated to further reduce the distance between the anchor head and the grouting pipe. At this time, the support structure is unfolded under compression until the end of the support structure abuts against the hole wall. The driving structure is started to drive the threaded connecting rod to drive the anchor head to rotate, and the rotation of the anchor head drives the support structure to rotate, and at the same time, the bottom surface and the hole wall are drilled. The waste generated by drilling is accumulated to a certain height to assist in the fixation of the lower end of the anchor rod. After the drilling is completed, the slurry is transported through the grouting channel and output to the drill hole through the grouting hole. The grouting pipe is lifted while grouting until the initial grouting is completed. At this time, the grouting at the lower part of the anchor rod forms an enlarged part facing downward and outward, which greatly enhances the connection strength between the anchor rod and the rock formation and improves the anti-floating performance of the anchor rod.

[0052] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An anti-floating anchor structure for hard rock foundation pit construction, characterized in that: It comprises a grouting pipe (1), a threaded connecting rod (2) movably arranged in the grouting pipe (1), an anchor head (3) arranged at the lower end of the grouting pipe (1) and detachably connected to the threaded connecting rod (2), a first ring body (4) arranged on the outer peripheral side of the end of the grouting pipe (1) close to the anchor head (3), a second ring body (5) arranged on the outer peripheral side of the end of the anchor head (3) close to the grouting pipe (1), and a supporting structure (6) with two ends respectively hinged to the first ring body (4) and the second ring body (5); The second ring body (5) comprises a second ring body main body (51), a limiting ring body (52) fixedly arranged on the anchor head (3) and located on a side of the second ring body main body (51) away from the first ring body (4), and at least two clamping members (53) hinged on the anchor head (3) and used for clamping and fixing the second ring body main body (51); The support structure (6) comprises at least a first rod (61) hinged to the first ring (4) and a second rod (62) hinged to the second ring (5); an end of the first rod (61) away from the first ring (4) is hinged to an end of the second rod (62) away from the second ring (5); The clamping member (53) comprises a side slot (531) arranged at the end of the anchor head (3), a fixing rod (532) arranged between the groove walls on both sides of the side slot (531), a clamping plate (533) having one end rotatably connected to the fixing rod (532) and the other end extending radially along the anchor head (3) to the outside of the anchor head (3), and a retaining piece (534) arranged at the connection between the clamping plate (533) and the side slot (531); The retaining member (534) comprises a mounting opening (534a) arranged on the end of the clamping plate (533) located in the side slot (531), and a torsion spring (534b) sleeved on the rod body of the fixing rod (532) located at the mounting opening (534a) and connected to the side slot (531).

2. The anti-floating anchor structure for hard rock foundation pit construction according to claim 1 is characterized by: The number of the clamping members (53) is 3 to 6, and they are distributed at intervals along the circumference of the anchor head (3).

3. The anti-floating anchor structure for hard rock foundation pit construction according to claim 1 is characterized by: A mounting block (621) is provided at the end of the second rod body (62) away from the second ring body (5), and chisel teeth (622) are provided on the mounting block (621).

4. The anti-floating anchor structure for hard rock foundation pit construction according to claim 1 is characterized by: The first ring body (4) comprises a first ring body main body (41) and two mounting protrusions (42) arranged on the outer surface of the grouting pipe (1) and used to fix the position of the first ring body main body (41).

5. The anti-floating anchor structure for hard rock foundation pit construction according to claim 1 is characterized by: A spiral rib (31) is provided on the outer surface of the anchor head (3), and a threaded hole (32) is provided at the end of the anchor head (3) to be threadedly connected to the threaded connecting rod (2).

6. The anti-floating anchor structure for hard rock foundation pit construction according to claim 1, characterized in that: A grouting channel (11) is provided in the grouting pipe (1), and a grouting hole (12) communicating with the grouting channel (11) is provided on the pipe wall of the grouting pipe (1).

7. The anti-floating anchor structure for hard rock foundation pit construction according to claim 6 is characterized by: The grouting channel (11) is provided with a reduced diameter section (13) adapted to the threaded connecting rod (2) near the anchor head (3).

8. The anti-floating anchor structure for hard rock foundation pit construction according to claim 1, characterized in that: The number of the supporting structures (6) is 3 to 6.

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