A tensile-shear coupling compensation anti-leakage type prestressed anchor rod and a construction method thereof

Abstract

The application provides a tension-shear coupling compensation anti-leakage type prestressed anchor rod and a construction method, relates to the technical field of tunnel, slope or foundation pit support, and comprises a rod body, the rod body comprises an anchoring part and an anti-seepage part, the anchoring part is used for fixing an anchoring agent, the anti-seepage part is connected with an anti-seepage layer, and the anti-seepage layer is located at the orifice position of an anchor hole; the anti-seepage layer is arranged at the orifice position of the anchor hole, a seepage plugging structure can be formed on the front surrounding rock, water pressure and seepage can be relieved and plugged, the cohesion and friction angle of the weak structural surface and the shear stress concentration position of the surrounding rock can be effectively enhanced, the stability of the surrounding rock is improved, production safety is ensured, production efficiency is improved, and the construction environment is optimized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel, slope or foundation pit support, in particular to a tension-shear coupling compensation anti-leakage type prestressed anchor rod and construction method. BACKGROUND

[0002] At present, the traditional anchor rod used in the field of urban rail transit tunnel, slope or foundation pit does not exert prestress, cannot exert minimum principal stress on the free surface, and cannot form a prestressed arch to enhance the stability of surrounding rock; the shear resistance of the traditional anchor cable is compensated by the axial tensile stress of the anchor cable, which is easy to cause the dispersion of tensile stress and even loss during the resistance to shear deformation.

[0003] Moreover, in water-rich strata, the drawbacks of traditional anchor rods have not been taken seriously, which affects the civilized construction, and mainly affects the formation of seepage channels in the shallow surrounding rock after drilling and setting, reduces the cohesion and friction angle of the weak structural plane and shear stress concentration of the surrounding rock, reduces the stability of the surrounding rock, and affects the safety of production. At the same time, if the surrounding rock contains illite montmorillonite, it is easy to cause the expansion of the shallow surrounding rock to the free surface, which further affects the safety of production. SUMMARY

[0004] The present application aims to provide a tension-shear coupling compensation anti-leakage type prestressed anchor rod and construction method, which can form a seepage plugging structure in the front surrounding rock, so that the water pressure and seepage are relieved and plugged, and the stability of the surrounding rock is enhanced;

[0005] The present application provides a tension-shear coupling compensation anti-leakage type prestressed anchor rod, comprising a rod body, the rod body comprises an anchoring part and an anti-seepage part, the anchoring part is used for fixing an anchoring agent, the anti-seepage part is connected with an anti-seepage layer, and the anti-seepage layer is located at the orifice position of the anchor hole.

[0006] Further, the anti-seepage layer comprises a waterproof plugging layer, which is used for plugging the excess hole.

[0007] Further, the anti-seepage layer further comprises a waterproof cushion layer, which is located outside the waterproof plugging layer, and the waterproof cushion layer is used for blocking the seepage water.

[0008] Further, the anti-seepage layer further comprises a surrounding rock coupling layer, which is located outside the waterproof cushion layer and flush with the free surface of the surrounding rock.

[0009] Further, the anchor hole comprises a hole expansion section, which is located at the orifice of the anchor hole, and the anti-seepage layer is tightly embedded inside the hole expansion section.

[0010] Further, the rod body further comprises a compensation part, the compensation part is located between the anchoring part and the anti-seepage part, and an outer side of the compensation part is sleeved with a drilling steel casing pipe.

[0011] Further, two ends of the compensation part are respectively sleeved with tensile-shear coupling compensation bodies, the tensile-shear coupling compensation bodies are hollow circular truncated cone-shaped, small end faces of the two tensile-shear coupling compensation bodies are oppositely arranged, and two ends of the drilling steel casing pipe are respectively connected with the two tensile-shear coupling compensation bodies.

[0012] Further, the drilling steel casing pipe comprises a drilling section, a casing section and a connecting section connected in sequence, the drilling section comprises an outward-expanding drill bit, the casing section is provided with parallel or spiral circumferential slits on a pipe wall, and the connecting section is provided with a connecting mechanism for being connected with a drilling machine.

[0013] Further, an outer side of the surrounding rock coupling layer is provided with a tray, and the tray is provided with a grouting hole.

[0014] The application further provides a construction method of the tensile-shear coupling compensation anti-seepage type prestressed anchor rod.

[0015] S1: determining an anchoring position, and drilling the anchor hole at the anchoring position;

[0016] S2: arranging the tensile-shear coupling compensation body at one end of the compensation part close to the anchoring part;

[0017] S3: placing the anchoring agent in the anchor hole, and sending the anchoring agent to the bottom of the anchor hole by the rod body;

[0018] S4: connecting the rod body with an anchor rod drilling machine at one end of the rod body located outside the drilling hole, starting the anchor rod drilling machine, breaking and rotating the anchoring agent to be consolidated, and then disconnecting the rod body from the anchor rod drilling machine;

[0019] S5: connecting the drilling steel casing pipe with the anchor rod drilling machine, starting the anchor rod drilling machine to sleeve the drilling steel casing pipe on the rod body and send the drilling steel casing pipe into the anchor hole, and then disconnecting the drilling steel casing pipe from the anchor rod drilling machine;

[0020] S6: expanding a hollow drill bit to be installed to the anchor rod drilling machine, and drilling the surrounding rock with the center of the rod body as the center to form the reaming section;

[0021] S7: arranging the tensile-shear coupling compensation body at one end of the compensation part close to the anti-seepage part;

[0022] S8: arranging the anti-seepage layer in the reaming section;

[0023] S9: mounting a tray and an anchorage device on a part of the rod body exposed from the anchor hole.

[0024] S10: tensioning the rod body to a prestress value.

[0025] The technical scheme of the present application can form a seepage blocking structure for the front surrounding rock by setting the anti-seepage layer at the orifice position of the anchor hole, so that the water pressure and seepage are relieved and blocked, the cohesion and friction angle of the weak structural surface and shear stress concentration of the surrounding rock are effectively enhanced, the stability of the surrounding rock is improved, the production safety is ensured, the production efficiency is improved, and the construction environment is optimized. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme in the specific embodiments or prior art of the present application, the drawings needed in the specific embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0027] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0028] Figure 2 It is a schematic diagram of the present application Figure 1 Another perspective view;

[0029] Figure 3 It is a schematic diagram of the anti-seepage layer of the present application;

[0030] Figure 4 It is an exploded view of the main body structure of the present application;

[0031] Figure 5 It is a schematic diagram of the parallel slotted pipe of the present application;

[0032] Figure 6 It is a schematic diagram of the slotted pipe surrounded by the present application;

[0033] Explanation of reference signs:

[0034] 1-rod body, 101-anchor part, 102-compensation part, 103-anti-seepage part, 2-anchor agent, 3-anti-seepage layer, 301-water blocking layer, 302-waterproof cushion layer, 303-surrounding rock coupling layer, 4-anchor hole, 5-hole expanding section, 6-drilling steel casing, 7-drilling section, 8-casing section, 9-connection section, 10-tension shear coupling compensation body. DETAILED DESCRIPTION

[0035] The technical solutions of the present application will be clearly and completely described below in conjunction with the embodiments. 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 skilled in the art without creative work fall within the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0037] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited. In addition, the terms "mounting", "connecting", "connecting" should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0038] Embodiment 1

[0039] As shown in Figure 1 and Figure 2 The present application provides a tensile-shear coupling compensation anti-leakage type prestressed anchor rod, which comprises a rod body 1, the rod body 1 comprises an anchoring part 101 and an anti-seepage part 103, the anchoring part 101 is used for connecting an anchoring agent 2, and the anti-seepage part 103 is connected with an anti-seepage layer 3, and the anti-seepage layer 3 is located at the hole opening position of an anchor hole 4.

[0040] Specifically, the rod body 1 can be a steel anchor rod, a glass steel anchor rod, or an anchor cable steel strand, etc. When the rod body 1 is a steel anchor rod or a glass steel anchor rod, the rod body 1 can be lengthened by using a joint rod screw. The anchoring part 101 and the anti-seepage part 103 are two end parts of the rod body 1. The anchoring part 101 has a certain length and is used to fix the anchoring agent 2. The anti-seepage part 103 has a shorter length and is used to fix the anti-seepage layer 3. The anchor hole 4 is drilled on the surrounding rock by using an anchor rod drilling machine. The anchoring agent 2 is inserted into the anchoring part 101 and is sent into the anchor hole 4 by the rod body 1. The anchoring agent 2 is made of a resin anchoring agent 2, an unsaturated polyester resin anchoring agent 2, or a polyurethane anchoring agent 2. Such anchoring agents 2 can be purchased on or off the market. The number of the anchoring agent 2 can be freely designed according to the hole diameter and depth of the anchor hole 4. The anti-seepage layer 3 is used to block and isolate the seepage channel and prevent the seepage channel formed in the shallow surrounding rock after drilling from reducing the cohesion and friction angle of the shear stress concentration of the weak structural plane of the surrounding rock, thereby reducing the stability of the surrounding rock. The anti-seepage layer 3 can be a combined layer or a special material layer as long as it can effectively block the seepage. In addition, the end part of the rod body 1 exposed outside the anchor hole 4 is also connected with a positioner, an anchor, and a lock.

[0041] As shown in Figure 3 , the anti-seepage layer 3 includes a waterproof sealing layer 301. The waterproof sealing layer 301 is used to seal the excess hole.

[0042] Specifically, the waterproof sealing layer 301 is made of a plastic waterproof glue, a coating waterproof layer, etc. It is located closest to the surrounding rock side (or closely adheres to the surrounding rock), has a gap between the rod body 1 and the anchor hole 4, or a grouting hole reserved in the anchor hole 4, etc., which can all cause seepage. The waterproof sealing layer 301 is annular. The inner ring and the outer ring are closely adhered to the rod body 1 and the surrounding rock surface respectively to seal the seepage.

[0043] As shown in Figure 3 , the anti-seepage layer 3 also includes a waterproof cushion layer 302. The waterproof cushion layer 302 is located outside the waterproof sealing layer 301. The waterproof cushion layer 302 is used to block the seepage water.

[0044] Specifically, the waterproof cushion layer 302 is made of a waterproof cement mortar, a coiled material, a coating, etc. It is located outside the waterproof sealing layer 301. The thickness of the waterproof cushion layer 302 is slightly smaller than that of the waterproof sealing layer 301. Since it is not directly in contact with the surrounding rock, it has better waterproof performance and longer service life, and can provide additional waterproof performance for the anti-seepage layer 3.

[0045] As shown in Figure 3 , the anti-seepage layer 3 also includes a surrounding rock coupling layer 303. The surrounding rock coupling layer 303 is located outside the waterproof cushion layer 302 and is flush with the surrounding rock surface. The surrounding rock coupling layer 303 is used to provide a stress transmission medium and pressure for the waterproof sealing layer 301 and the waterproof cushion layer 302.

[0046] Specifically, the material of the surrounding rock coupling layer 303 is waterproof cement mortar, which is located outside the waterproof cushion layer 302 and flush with the free surface of the surrounding rock. The surrounding rock coupling layer 303 is the outermost waterproof structure, which is firm and stable after forming, and can resist corrosion and other harsh conditions. On the one hand, the surrounding rock coupling layer 303 can provide a stress transmission medium for the waterproof plugging layer 301 and the waterproof cushion layer 302, and improve the mechanical properties and service life of the waterproof plugging layer 301 and the waterproof cushion layer 302. On the other hand, the surrounding rock coupling layer 303 can provide a certain pressure to make the entire anti-seepage layer 3 closely fit, thereby improving the waterproof performance.

[0047] As shown in Figure 1 and Figure 2 , the anchor hole 4 includes a reaming section 5, which is located at the opening of the anchor hole 4, and the anti-seepage layer 3 is closely fitted inside the reaming section 5.

[0048] Specifically, the reaming section 5 is located near the free surface of the surrounding rock. The reaming section 5 is a concentric circle with the anchor hole 4, with the anchor rod center point as the center. The hole diameter of the reaming section 5 is greater than 2 times the hole diameter of the anchor hole 4. The depth of the reaming section 5 can be 10% of the length of the anchor rod, which is determined according to the seepage water pressure. The reaming section 5 is mainly used for installing the anti-seepage layer 3. Since there is a stepped surface with a reduced cross section between the reaming section 5 and the anchor hole 4, when the anti-seepage layer 3 is closely fitted in the reaming section 5, the flow resistance and anti-seepage effect are better.

[0049] As shown in Figure 4 , the rod body 1 further includes a compensation part 102, which is located between the anchoring part 101 and the anti-seepage part 103. The outer side of the compensation part 102 is sleeved with a drilling steel casing pipe 6.

[0050] Specifically, the compensation part 102 is a section of the rod body 1 located between the anchoring part 101 and the anti-seepage part 103. It is mainly used for sleeving the drilling steel casing pipe 6 and fixing the tension-shear coupling compensation body 10 to compensate and convert the tensile stress and shear stress of the anchor rod, thereby improving the mechanical properties of the anchor rod. If the length of the rod body 1 is insufficient, the drilling steel casing pipe 6 can be connected.

[0051] As shown in Figure 4 , the two ends of the compensation part 102 are respectively sleeved with a tension-shear coupling compensation body 10. The tension-shear coupling compensation body 10 is a hollow circular truncated cone. The small ends of the two tension-shear coupling compensation bodies 10 are oppositely arranged. The two ends of the drilling steel casing pipe 6 are respectively connected with the small ends of the two tension-shear coupling compensation bodies 10.

[0052] Specifically, the tension-shear coupling compensation body 10 is similar to a hollow circular truncated cone, the maximum diameter of which is smaller than the diameter of the borehole, two tension-shear coupling compensation bodies 10 are welded at two ends of the compensation part 102 (or the connection parts of the compensation part 102, the anchoring part 101 and the anti-seepage part 103), and the small end faces of the two tension-shear coupling compensation bodies 10 are both directed to the central position of the compensation part 102; it should be easily understood that, when the rod body 1 is subjected to tensile stress, the shear resistance of the rod body 1 can be improved due to the tension-shear coupling compensation body 10 in the form of a circular truncated cone, and when the rod body 1 is subjected to shear stress, the tensile resistance of the rod body 1 can be improved due to the tension-shear coupling compensation body 10 in the form of a circular truncated cone, that is, the two tension-shear coupling compensation bodies 10 can effectively optimize the distribution of the tensile stress and the shear stress borne by the anchor rod; the drilling steel casing 6 can support and protect the inner wall of the anchor hole 4 outwardly and protect the rod body 1 inwardly.

[0053] As shown in Figure 5 and Figure 6 , the drilling steel casing 6 comprises a drilling section 7, a casing section 8 and a connecting section 9 connected in sequence, the drilling section 7 comprises an outwardly expanding drill head, the casing section 8 is provided with parallel or spiral circumferential slits on the pipe wall, and the connecting section 9 is provided with a connecting mechanism for connecting with a drilling machine.

[0054] Specifically, the drilling steel casing 6 is a tubular material, the drilling section 7 is an outwardly expanding hollow drill head structure formed by machining one end of a steel pipe raw material before construction, the diameter of the outwardly expanding hollow drill head is slightly smaller than the diameter of the drill head of the drilling machine, that is, the drilling steel casing 6 can be rotated and drilled into the anchor hole 4 through the drilling section 7, the diameter of the drilling section 7 is greater than the minimum diameter of the tension-shear coupling compensation body 10 and smaller than the maximum diameter of the tension-shear coupling compensation body 10; a plurality of slits are formed on the outer side of the pipe wall of the casing section 8, the slits can be machined into slits parallel to the axial direction of the steel casing rod body 1 or reverse drilling spiral slits along the axial direction of the steel casing rod body 1, which can help to scrape the hole wall of the anchor hole 4 during the drilling process of the entire drilling steel casing 6, and can be used for grouting into the anchor hole 4 when necessary; the connecting section 9 is the tail end of the entire drilling steel casing 6, and the connecting mechanism can be a pin or a thread machined to match the anchor rod drilling machine, which can be connected with the anchor rod drilling machine.

[0055] A tray is arranged outside the surrounding rock coupling layer 303, and a grouting hole is formed in the tray.

[0056] Specifically, the purpose of the grouting hole is to perform secondary grouting to block the seepage water when necessary.

[0057] The application further provides a construction method of the tension-shear coupling compensation anti-seepage type prestressed anchor rod, which comprises the following steps:

[0058] S1: determining an anchoring position, and drilling an anchor hole 4 at the determined anchoring position;

[0059] S2: The tensile-shear coupling compensation body 10 is arranged near one end of the anchoring part 101;

[0060] S3: The anchoring agent 2 is put into the anchor hole 4, and the rod body 1 sends the anchoring agent 2 to the bottom of the anchor hole 4;

[0061] S4: The rod body 1 is connected to the anchor rod drill at one end outside the drill hole, the anchor rod drill is started, the anchoring agent 2 is broken and rotated to be consolidated, and then the connection between the rod body 1 and the anchor rod drill is released;

[0062] S5: The drilling steel sleeve 6 is connected to the anchor rod drill, the anchor rod drill is started to sleeve the drilling steel sleeve 6 on the rod body 1 and rotate to send it into the anchor hole 4, and then the connection between the drilling steel sleeve 6 and the anchor rod drill is released;

[0063] S6: The enlarged hollow drill bit is installed to the anchor rod drill to drill the surrounding rock with the center of the rod body 1 as the center to form the reaming section 5;

[0064] S7: The tensile-shear coupling compensation body 10 is arranged near one end of the anchoring part 101;

[0065] S8: The anti-seepage layer 3 is arranged in the reaming section 5;

[0066] S9: The part of the rod body 1 exposed from the anchor hole 4 is installed with a tray and an anchor;

[0067] S10: The rod body 1 is tensioned to a prestressed value.

[0068] Specifically:

[0069] In S1, if there are sundries remaining in the anchor hole 4 after drilling, the anchor hole 4 can be cleaned, for example, high-pressure air flushing or water flushing;

[0070] In S2, the small end of the tensile-shear coupling compensation body 10 faces the anti-seepage part 103;

[0071] In S3, if the rod body 1 is not deep enough in the anchor hole 4, multiple rod bodies 1 can be connected to meet the requirements;

[0072] In S4, the anchor rod drill is rotated for 5-10 seconds or until the anchor rod drill cannot rotate;

[0073] In S5, if the drilling steel sleeve 6 is not deep enough in the anchor hole 4, multiple drilling steel sleeves 6 can be connected to meet the requirements;

[0074] In S7, the small end of the tensile-shear coupling compensation body 10 faces the anchoring part 101, and the maximum diameter section of the tensile-shear coupling body is deeper than the enlarged section position;

[0075] In S8, including S8.1: the waterproof plugging layer 301 material is applied to plug the deepest section of the enlarged section; S8.2: the waterproof cushion layer 302 is installed outside the waterproof plugging layer 301; S8.3: the surrounding rock coupling layer 303 is arranged outside the waterproof cushion layer 302 and is flush with the surrounding rock.

[0076] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A tensile-shear coupling compensation anti-leakage type prestressed anchor rod, characterized in that, The rod body comprises an anchoring part for fixing an anchoring agent and an anti-seepage part on which an anti-seepage layer is connected, and the anti-seepage layer is located at the orifice position of the anchor hole. The anti-seepage layer comprises a waterproof sealing layer for sealing excess channels. The anti-seepage layer further comprises a waterproof cushion layer located outside the waterproof sealing layer, and the waterproof cushion layer is used for blocking seepage water. The anti-seepage layer further comprises a surrounding rock coupling layer located outside the waterproof cushion layer and flush with the free surface of the surrounding rock. The anchor hole comprises a hole expansion section located at the orifice of the anchor hole, and there is a stepped surface with a reduced cross section between the hole expansion section and the anchor hole, and the anti-seepage layer is tightly embedded inside the hole expansion section. The rod body further comprises a compensation part located between the anchoring part and the anti-seepage part, and a drilling steel casing is sleeved outside the compensation part. Two ends of the compensation part are respectively sleeved with tensile-shear coupling compensation bodies, the tensile-shear coupling compensation bodies are hollow circular truncated cone-shaped, small end faces of the two tensile-shear coupling compensation bodies are oppositely arranged, and two ends of the drilling steel casing are respectively connected with the two tensile-shear coupling compensation bodies; when the rod body is subjected to tensile stress, the tensile-shear coupling compensation bodies of the circular truncated cone shape can improve the shear resistance of the rod body; when the rod body is subjected to shear stress, the tensile-shear coupling compensation bodies of the circular truncated cone shape can improve the tensile resistance of the rod body, that is, the two tensile-shear coupling compensation bodies can optimize the distribution of the tensile stress and shear stress of the anchor rod.

2. The anti-leakage type prestressed anchor rod of claim 1, wherein, The drilling steel casing comprises a drilling section, a casing section and a connecting section connected in sequence, the drilling section comprises an outwardly expanding drill bit, the casing section is provided with parallel or spiral circumferential slits on the pipe wall, and the connecting section is provided with a connecting mechanism for connecting with a drilling machine.

3. The anti-leakage type prestressed anchor rod of claim 2, wherein, A tray is arranged outside the surrounding rock coupling layer, and a grouting hole is arranged on the tray.

4. A construction method of the anti-leakage type prestressed anchor rod with the tensile-shear coupling compensation according to claim 2, characterized in that, The method comprises the following steps: S1: determining an anchoring position, and drilling the anchor hole at the anchoring position; S2: arranging the tensile-shear coupling compensation body at one end of the compensation part close to the anchoring part; S3: placing the anchoring agent in the anchor hole, and sending the anchoring agent to the bottom of the anchor hole by the rod body; S4: connecting the anchor rod drilling machine to one end of the rod body outside the borehole, starting the anchor rod drilling machine, breaking and rotating the anchoring agent to solidify, and then disconnecting the rod body and the anchor rod drilling machine; S5: connecting the drilling steel casing with the anchor rod drilling machine, starting the anchor rod drilling machine to sleeve the drilling steel casing on the rod body and rotate to send it into the anchor hole, and then disconnecting the drilling steel casing and the anchor rod drilling machine; S6: expanding the hollow drill bit to be installed to the anchor rod drilling machine, and drilling the surrounding rock with the center of the rod body as the center to form the hole expansion section; S7: arranging the tensile-shear coupling compensation body at one end of the compensation part close to the anti-seepage part; S8: arranging the anti-seepage layer in the hole expansion section; S9: installing the tray and the anchorage device on the part of the rod body exposed from the anchor hole; S10: tensioning the rod body to a prestressed value.

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