CN2448925Y - Expansion crack pressure type prestressed mud injection anchor - Google Patents

Abstract

The utility model discloses an expansion crack type pressure type prestressed mud injection anchor tool composed of a prestressed rod body (1), a hollow rod body (2), an inner pressure bearing plate (3), an anchor head (4), a protective cover (5), an expansion device (6), an exhaust pipe (7), an outer pressure bearing plate (8), a mud stopping plug (9), an upper stop block (10), a lower stop block (11), etc. Meanwhile, the expansion crack type pressure type prestressed mud injection anchoring tool also provides a determining method of the application parameter of the anchor tool. Compared with a traditional prestressed anchor cable, the utility model has simple structure, convenient installation and low price. Compared with the common sand slurry anchoring rod support, the utility model has large support rigidity, high support reverse force and strong deformability for controlling surrounding rocks. The quality of a supporting structure is enhanced and support cost can be markedly lowered.

Description

Expansive pressure type prestressed grouting anchor

The utility model belongs to the field of supporting or reinforcing geotechnical engineering, and can be used for supporting or reinforcing various tunnels, shafts, side slopes, foundation pits and the like.

The ordinary mortar bolts widely used now, due to the hysteresis effect and passive bearing, the actual force of the bolt is very small, and the ability to control deformation is very poor. If the prestressed bolt is used, the situation will change; the current prestressed anchor cable has a complex structure , the price is expensive, and it is difficult to be widely used in various projects, especially tunnel projects.

The purpose of the utility model is to provide a kind of expansion-cracking pressure type prestressed grouting anchor with simple structure, low price and early bearing capacity for soft rock engineering, especially soft soil tunnel engineering.

In order to solve the above-mentioned tasks, the solution of the utility model is: replace the traditional single rod with several rods with different functions, at least one of which is a prestressed rod (1), and the inner end of the rod is equipped with an inner pressure plate (3 ), the expansion anchor head (4); the exposed end passes through the upper and lower pier (10), (11), and the rod body (1) mainly bears the prestressed tension load, and a deformation load rod body ( 2), these rods are made of high-strength steel or glass fiber resin.

Expansion-type pressure prestressed grouting anchorage, also known as TZL series anchorage, where T represents the inventor's surname, ZL is the first letter of Chinese pinyin for expansion and cracking; it consists of a prestressed rod body (1), a hollow rod body ( 2), inner pressure plate (3), anchor head (4), protective cover (5), expander (6), exhaust pipe (7), outer pressure plate (8), grout stopper (9 ), the upper pier (10), the lower pier (11), the nut (12), bellows (20).

The anchor head (4) is composed of an expansion shell (13) and an inverted wedge (14). The outer surface of the expansion shell is a cylindrical surface. There is no less than one connection point (16), the outer surface of the expansion shell is hollowed out, and the inner surface is a tapered surface; for the anchorage that uses a spring compression expander, the inner hole wall at the end of the expansion shell is provided with no less than two rings shaped protrusions (40), the inverted wedge wall is hollowed out, and the outer surface still maintains a continuous conical surface; there are no less than two longitudinal protrusions (17) on the outer side of the inverted wedge, which cooperate with the expansion joint of the expansion shell, and the tail end shrinks into a cylindrical shape. Thread (18) is locally established.

The pier is composed of upper and lower parts, both of which are cylindrical. The bottom surface of the lower pier (11) is a slope (21), and the upper surface is a truncated spherical surface (22); the upper pier (10) has no less than two holes. (23), the bottom is provided with a large hole that cooperates with the grout stopper, and the upper and lower pads form a spherical hinge support; the solid part of the pad is hollowed out, and the upper and lower pads are formed with high-strength plastic or cast iron.

The expander (6) can be spring compression type or pin wheel type, and the spring compression type expander is composed of expansion shell release ring (31), torsion spring (32), compression spring (33), support ring (38), positioning pin (36), lead wire (37); the lower end of the compression spring is placed on the support ring (38), the support ring is screwed or sleeved on the rod body, the upper end of (33) presses the tail end of the expansion shell; the expansion shell release ring (31) It is a cylindrical combination, and there are no less than two annular protrusions (40) on the outer side of the upper part, which cooperate with the annular protrusions in the inner hole at the end of the expansion shell, drill a hole in the center, and set threads locally to cooperate with the threads of the rod body; the torsion spring (32) One protrudes from the upper and lower sides, one of which is inserted into the reserved hole (34) of the support ring sleeve, and the other is fixed on the columnar protrusion of (31); the positioning pin positions the expansion shell release ring on the expansion shell In the tip hole (35) at the tail end, the lead wire (37) at the tail end of the positioning pin extends to the outside of the drilled hole; except for the expansion shell release ring and the insertion pin, the rest of the components are combined into one when leaving the factory, and the compression spring (33) is placed in a supported position. pressure state.

The needle-wheel type expander is made up of involute wheel (41), positioning needle bar (42), spring (43), and shell (44). The expander penetrates the rod body and passes through the protrusion (45 ) combined with the notch of the rod body, when the involute wheel rotates, the needle bar will be extruded from the side wall shell of the expander; the needle wheel expander has a simple structure and is suitable for short anchor rods, and the spring compression expander can be used for Longer shaft.

The grout stopper is cylindrical, the upper part is inserted into the round hole on the lower surface of the upper pier, and connected to each other as a whole, and the upper part of the grout stopper is provided with no less than two round holes (51) of different diameters for rod body, grouting Pipe etc. are inserted;

The protective cover (5) is a combination of a cylinder and an ellipsoid, hollow to accommodate the nut (12), and the end of the inner hole is partially threaded to cooperate with the thread (18) at the end of the inverted wedge. Expansion pressure type prestressed grouting The application parameters of the anchorage are determined by the dimensionless characteristic line method according to the following steps:

(1) Preliminary selection of primary support design parameters with typical engineering analogy;

叫松驰系数；(2) Establish dimensionless surrounding rock feature line ψ=f(λ), define It is called the virtual load coefficient or the reaction force coefficient;

called relaxation coefficient;

When the wall rock is elastic: ψ=1-λ;

When the wall rock is elastic-plastic: ψ=1-λ ^x0 (0<x ₀ <1) and ${\mathrm{\&psi;}}_t=\frac{q_t}{{\mathrm{\&sigma;}}_0},$ where _qt is the slump load, $x_0=\frac{1\mathrm{no}(1-{\mathrm{\&psi;}}_f)}{1\mathrm{no}{\mathrm{\&lambda;}}_f};$

(3) Establish dimensionless support characteristic line ψ=Sλ, define $S=\frac{{\mathrm{ku}}_{\&infin;}^{\mathrm{\&gamma;}}}{{\mathrm{\&sigma;}}_0}$ is the dimensionless stiffness of the support, and k is the support stiffness;

(4) Determine their reaction force coefficients on the dimensionless characteristic line according to the setting position and sequence of each component of the support;

In Fig. 8, 1 is the characteristic line of surrounding rock, 2 is the characteristic line of combined support, 3 is the characteristic line of bolt support, λ _f is the relaxation coefficient of the working face, ψ _f is the virtual load coefficient of the working face, and ψ _m is the bolt reaction coefficient, then bolt support reaction force σ _Wm =ψ _m σ ₀ ;

(5) Calculate the working load of the mortar anchor P _W =σ _Wm e _a e _c , where e _a and e _c are the distances between the mortar anchors along the two directions;

(6) Determine the design tensile load P _R of the prestressed anchor according to the bearing capacity of the anchor;

(7) Adjust the prestressed anchor spacing x _c , x _a according to the formula; $x_c={(1+\frac{P_R}{P_W})}^{\frac{1}{2}}{\left(\frac{{\mathrm{no}}_e}{{\mathrm{no}}_x}\right)}^{\frac{1}{2}}{e}_c$ $(\frac{x_a}{x_c}={\mathrm{no}}_x,\frac{e_a}{e_c}={\mathrm{no}}_e)$ when ${\mathrm{no}}_e={\mathrm{no}}_x=1,x={(1+\frac{P_R}{P_W})}^{\frac{1}{2}}e$

For the local area cut into separate bodies by the structural plane, the standard sliding force should be taken as the ordinate, and the standard sliding displacement should be used as the abscissa to establish the characteristic line, and the anchor spraying net support should be designed accordingly.

The above method is not a design method that completely matches with the New Austrian Method. If the conditions for selecting the original data are mature, the dimensionless characteristic line should be used to directly design the parameters of each component of the composite support in one step;

Since the anchorage used is the TZL series and the design method used is the characteristic line method, this method is also called the double T operation method.

Compared with the prior art, the utility model has the following significant advantages:

(1) The spherical hinge support can adapt to different slopes of the orifice and drilling in various anchoring directions, thus simplifying the leveling process of the orifice, automatically adjusting the axis of the rod body to be parallel to the axis of the drilling hole during tension, and reducing the loss of prestress during tension ;

(2) Compared with the existing prestressed anchor cables, the utility model has a simple structure, is easy to install, and is cheap;

(3) Compared with the existing ordinary mortar bolt support, the utility model has the advantages of large support rigidity, high support reaction force, strong ability to control the deformation of the surrounding rock, can reduce the convergence displacement of the tunnel, and improve the ground pressure of the support. carrying capacity.

(4) The anchor bolt parameters designed according to the characteristic line will greatly reduce the amount of anchor bolts.

Below in conjunction with embodiment the utility model is described in further detail:

Fig. 1 is the structural representation of the utility model embodiment one;

Fig. 2 is the structural representation of the second embodiment of the utility model;

Fig. 3 is the structural representation of anchor head of the present utility model;

Fig. 4 is a schematic structural view of the upper and lower pier of the utility model;

Fig. 5 is a schematic structural view of the spring compression type expander of the present invention;

Fig. 6 is a schematic structural view of the pin wheel expander of the present invention;

Fig. 7 is a schematic structural view of the utility model stopper;

Figure 8 is a schematic diagram of dimensionless surrounding rock feature lines and support feature lines.

Embodiment 1: Expansive pressure type double-rod prestressed grouting anchor.

Figure 1 is a schematic diagram of its structure, which consists of an unbonded rod body 1, a steel pipe 2, an inner pressure plate 3, an anchor head 4, a protective cover 5, an expander 6, an exhaust pipe 7, and an outer pressure plate 8. The grout stopper 9, the upper pier 10, the lower pier 11, and the nut 12; the anchor head is composed of an expansion shell 13 and an inverted wedge 14, and the outer surface of the expansion shell is cylindrical and provided with three through-length expansion joints 15 , there are connection points 16 at the middle and end of the expansion joint, the outer surface of the expansion shell is hollowed out into a discontinuous rectangular block, the inner surface of the expansion shell is conical, and the inner hole wall at the end of the expansion shell is provided with discontinuous three-stage bottleneck thread The inverted wedge wall is hollowed out into a radial wheel shape, and the outer surfaces on both sides are still continuous tapered surfaces; there are three longitudinal protrusions 17 on the outer side of the inverted wedge to cooperate with the expansion joints of the shell, and threads 18 are partially provided on the shrinking cylindrical surface at the tail end , combined with the inner thread of the protective cover.

The pier is composed of upper and lower parts. The bottom surface of the lower pier 11 is an elliptical surface 21, and the upper surface is a truncated spherical surface 22; A large hole is provided to cooperate with the stopper, and the stopper is connected with screws; the solid part of the pier is hollowed out and made of high-strength plastic.

The spring compression expander is set close to the expansion shell, and is composed of an expansion shell release ring 31, a torsion spring 32, a compression spring 33, a support ring 38, a positioning pin 36, and a lead wire 37; the expansion shell release ring is provided with 3 annular protrusions and The bottle mouth thread at the end of the expansion shell is engaged, and the support ring is fixed on the rod body with screws.

The installation, grouting, and tensioning procedures of the expansion-type pressure-type double-rod prestressed grouting anchor are: drilling, cleaning the hole, and sequentially combining the inner pressure plate, nut, expander, anchor head, and protective cover. On the rod body, hang the expansion shell release ring, tighten the torsion spring, insert the positioning pin, fix the support ring on the rod body with screws, release the compression spring, and insert the exhaust pipe into the reserved hole of the pressure bearing plate 3; The combined rod body together with the exhaust pipe is slowly sent into the drill hole. After it is in place, pull the lead wire 37, pull out the positioning pin 36, turn the expansion shell release ring 31 with the torsion spring, and make it disengage from the bottle mouth thread at the tail end of the expansion shell. The spring 33 pushes the expansion shell to open; insert the hollow rod body 2, put on the outer pressure plate, the lower pier, penetrate the slurry stopper and the upper pier in sequence, put on the nut, and perform the initial tension according to the displacement control, so that the expansion shell is completely Open it, and the installation is over; inject early-strength cement slurry, and when it reaches the design strength, it can be tensioned; this embodiment is suitable for tunnels or slopes with more than two types of soft rock, and the anchor rod length is more than 4 meters.

Example 2: Expansive pressure type single-rod prestressed grouting anchor

Figure 2 is a schematic diagram of its structure, which consists of a rolled threaded rib 1, a temporary grouting pipe 2, an inner pressure plate 3, an anchor head 4, a protective cover 5, an expander 6, an exhaust pipe 7, and an outer bearing Pressing plate 8, slurry stopper 9, upper pier 10, lower pier 11, nut 12, and plastic bellows 20; it differs from Embodiment 1 in that the expander adopts a pin-wheel structure, and the expander The involute wheel 41 is combined with the rod body through tenons and grooves 45; a plastic bellows is added outside the rod body, and its inner end is closely connected with the inner pressure plate, and its outer end is closely connected with the grout stopper. The grouting pipe 2 is removed after grouting .

The installation, grouting, and tensioning procedures of Embodiment 2 are: drilling, clearing holes, sequentially combining the inner pressure plate, nut, expander, anchor head, protective cover, exhaust pipe, and plastic bellows; The good rod body is slowly sent into the drilling hole, and when it is in place, the protective cover is pressed against the bottom of the hole, and then the anchor rod body is rotated counterclockwise to drive the involute wheel 41 to rotate, so that the positioning needle rod 42 is stretched out and pressed into the hole wall to prevent the expansion shaft Move to the direction; put on the outer pressure plate, upper pier and nut for initial tension, so that the expansion shell is opened; insert the grouting pipe from the reserved hole of the upper pier to grout outside the corrugated pipe, pull out the grout after the grout is full After the early-strength cement slurry reaches the design strength, it is stretched, and after the predetermined tension load is reached, the second grouting is made around the rod body from the reserved hole to facilitate long-term preservation of the prestress; the second embodiment is suitable for the second type Tunnel and slope support with very weak rock and soil and short anchor rods.

Claims (8)

1. A bursting pressure type prestressed grouting anchor, belonging to the field of rock and soil support or reinforcement, which includes a rod body (1), (2), an inner pressure plate (3), an anchor head (4), a protection Cover (5), expander (6), exhaust pipe (7), outer bearing plate (8), slurry stopper (9), upper and lower pads (10), (11), nut (12), The bellows (20) is characterized in that the rod body (1) includes at least one rod material, with threads at both ends, and its inner end is equipped with a bursting anchor head (4), a protective cover (5), an expander ( 6), the inner pressure plate (3), the rod body can also have a hollow pipe (2), and the rod body is made of high-strength steel or glass fiber resin; The anchor head (4) is composed of an expanding tube (13) and an inverted wedge (14). The strips are generally long expansion joints (15), and at least one connection point (16) is provided in the expansion joints, and both the inverted wedge and the expansion shell can be hollowed out; the upper and lower pads (10), (11) form a spherical joint support, and the contact surface is On the truncated spherical surface (22), there are not less than two holes on the upper pier (10), the bottom is provided with a large hole that matches the grout stopper, the bottom of the lower pier (11) is a slope (21), and the upper and lower pier The solid part can be hollowed out; the expander (6) can be spring-compressed or pinwheel-type, and the spring-compressed expander consists of an expansion shell release ring (31), a torsion spring (32), a compression spring (33), a support ring (38), positioning pin (36), lead wire (37), the pinwheel type expander is made up of involute wheel (41), positioning needle bar (42), spring (43), shell (44), and the pulp stop The plug (9) is cylindrical, and its upper part fits with the opening of the upper pier and is integrated with the upper pier. The upper part of the stopper is provided with no less than two round holes, and the lower part of the stopper is a large round hole; The application parameters of the expansion-burst pressure type prestressed grouting anchor combination support are determined by the dimensionless characteristic line according to the following steps, (1) Use the dimensionless characteristic line to determine the working load PW of the prestressed anchor; (2) Determine the design tensile load PR of the prestressed anchor according to the bearing capacity of the anchor; (3) Adjust the prestressed anchor spacing x _c , x _a according to the formula; $x_c={(1+\frac{P_R}{P_W})}^{\frac{1}{2}}{\left(\frac{{\mathrm{no}}_e}{{\mathrm{no}}_x}\right)}^{\frac{1}{2}}{e}_c$ $(\frac{x_a}{x_c}={\mathrm{no}}_x,\frac{e_a}{e_c}={\mathrm{no}}_e)$ when ${\mathrm{no}}_e={\mathrm{no}}_x=1,x={(1+\frac{P_R}{P_W})}^{\frac{1}{2}}e$ For the local area cut into separate bodies by the structural plane, the characteristic line should be established with the standardized sliding force as the ordinate and the standardized sliding displacement as the abscissa, and the application parameters of the prestressed bolt combination support should be determined accordingly; When the conditions for selecting the original data are mature, the parameters of each component of the prestressed bolt composite support should be designed in one step directly by using the dimensionless characteristic line. 2. According to claim 1, the expansive pressure type prestressed grouting anchor is characterized in that the working load P _W of the prestressed anchor rod is determined according to the following steps, a) Establish dimensionless surrounding rock characteristic line ψ=f(λ),

It is called the virtual load coefficient or reaction force coefficient, is called the relaxation coefficient; b) establish dimensionless support characteristic line ψ=Sλ, $S=\frac{{\mathrm{ku}}_{\&infin;}^{\mathrm{\&gamma;}}}{{\mathrm{\&sigma;}}_0}$ is the dimensionless stiffness of the support, and K is the support stiffness; c) Determine their reaction force coefficient ψ _i on the dimensionless characteristic line according to the setting position and sequence of each component of the support, then the bolt support reaction force σ _Wm =ψ _m σ ₀ , where ψ _m is the anchor support reaction coefficient; d) Calculate the working load of the anchor rod P _W =σ _Wm e _a e _c , where e _a and e _c are the distances between the anchor rods along the two directions. 3. According to claim 1, the expandable pressure-type prestressed grouting anchor is characterized in that the outer surface of the expansion shell 13 is cylindrical, the inner surface is conical, and there are no less than two expansion joints on the expansion shell. (15), at least one connection point (16) is provided in the expansion joint, and no less than two annular protrusions (40) can be provided on the inner side of the tail end of the expansion shell, and the outer surface of the expansion shell can be hollowed out. 4. According to claim 1, the expansive pressure-type prestressed grouting anchor is characterized in that the inverted wedge (14) is a cone, with a hole in the middle and a local thread, and no less than two longitudinal protrusions can be provided on the outer side of the inverted wedge (17), the inverted wedge wall can be hollowed out, the tail end shrinks into a cylindrical shape, and the outer part is provided with threads (18). 5. According to claim 1, the expansive pressure-type prestressed grouting anchorage is characterized in that the pier is composed of two parts, the upper pier (10) and the lower pier (11), both of which are cylindrical, and the bottom of the lower pier It is an inclined plane (21), and the upper surface is a truncated spherical surface (22); there are no less than two holes on the upper pier (10), the bottom is provided with a large hole matched with the grout stopper, and the lower surface is also a truncated spherical surface (22 ), the upper and lower pads form the spherical joint bearing. 6. According to claim 1, the expansive pressure type prestressed grouting anchor is characterized in that the spring compression type expander consists of an expansion shell release ring (31), a torsion spring (32), a compression spring (33), a support ring (38), locating pin (36), lead wire (37) are made up of, and except shell expansion release ring (31), locating pin (36), other parts are assembled into one, and compression spring (33) is in compressed state. 7. According to claim 1, the expansive pressure-type prestressed grouting anchor is characterized in that the pin wheel expander consists of an involute wheel (41), a positioning needle rod (42), a spring (43), and a casing (44 ) composition, the protrusion (45) on the inner hole of the involute wheel is combined with the gap of the rod body, and the rotation of the rod body drives the involute wheel (41) to extrude the needle rod (42) from the side wall of the expander. 8. According to claim 1, the expansive pressure-type prestressed grouting anchor is characterized in that the grout stopper is cylindrical, the upper end part is inserted into the opening on the lower surface of the upper pier, and the upper part of the grout stopper is provided with not less than Two circular holes (51) cooperate with the reserved holes of the upper pier, and the bottom of the grout stopper is a large circular hole (52).

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