CN107130988B - A liquid carbon dioxide blasting antireflection grouting composite anchor - Google Patents

Abstract

The invention discloses a liquid carbon dioxide blasting anti-reflection grouting composite anchor rod, which comprises an anchor rod body and an expansion shell anchoring head, wherein the anchor rod body comprises a liquid storage pipe, an energy discharging head fixedly connected to the front end of the liquid storage pipe and a filling head detachably connected to the rear end of the liquid storage pipe, a release pipeline communicated with the inner cavity of the liquid storage pipe is arranged in the energy discharging head, and an exhaust hole penetrating through the release pipeline is arranged on the outer wall of the energy discharging head; an energy release sheet is arranged between the inner cavity of the liquid storage pipe and the release pipeline; the expansion shell anchoring head is connected to the front end of the energy release head; the filling head is provided with a liquid filling hole communicated with the inner cavity of the liquid storage tube and a valve for controlling the liquid filling hole to be opened and closed, and the rear end of the inner cavity of the liquid storage tube is provided with a heating element. The invention induces cracking through liquid carbon dioxide blasting, effectively expands the range of a fracture zone in the rock body, and creates more favorable conditions for grouting reinforcement; meanwhile, the carbon dioxide blasting tube is directly used as a grouting channel to perform rock mass grouting reinforcement, so that the organic combination of induced blasting and grouting is realized.

Description

A liquid carbon dioxide blasting anti-reflection grouting composite anchor

technical field

The invention relates to the technical field of rock and soil reinforcement and support, in particular to a liquid carbon dioxide blasting anti-reflection grouting composite bolt.

Background technique

Bolt support is the most economical and effective method to solve stability problems in geotechnical engineering. It has been widely used in various projects such as slope treatment, deep foundation pit support, surrounding rock reinforcement, and structural compression. However, the support and reinforcement of broken rock masses has always been a difficult problem in the field of rock and soil anchoring engineering construction. Especially when the thickness of the broken rock mass exceeds a certain distance, the anchorage section supported by bolts or anchor cables can only act on the broken rock and soil mass. In the middle, the support functions such as suspension and extrusion cannot be formed, effective anchoring cannot be carried out, and the safety of the project cannot be guaranteed. However, when grouting support or combined anchoring and grouting support is used, in the case of insufficient development of cracks in the broken rock mass, the diffusion radius of the grouting slurry is small and the amount of grouting is low, resulting in a small thickness of the main and auxiliary bearing circles, and the roadway or Under the action of stress concentration, the surrounding rock of the upper wall of the stope will gradually lose its balance and form new damage, which is difficult to meet the purpose of strengthening the surrounding rock in the broken area.

In view of the poor connectivity of cracks in the broken rock mass and the small amount of grouting, some people have proposed to use the method of conventional blasting anti-reflection grouting for joint support of anchoring and grouting. Control, may lead to a sharp increase in the dense radial cracks around the blast hole, and it is impossible to form a uniform crack zone. After blasting, it is easy to cause new stress concentration in the deep surrounding rock explosion cracking zone, which will affect the stability of the surrounding rock. At the same time, the blasting safety factor of traditional explosives is low, the possibility of squibs cannot be ruled out, the applicable conditions are limited, the operation process is relatively complicated, and the dust and a large amount of harmful gases generated by blasting pollute the working environment.

Contents of the invention

The technical problem to be solved by the present invention is to provide a liquid carbon dioxide blasting anti-reflection grouting that realizes no pollution in the blasting process, adjustable energy, and controllable release mode when reinforcing the above-mentioned surrounding rocks with moderately developed joints and fissures and poor connectivity. Composite bolts to increase the range of cracks in the surrounding rock, expand the diffusion radius of the grout, improve the grouting effect of the surrounding rock, improve and improve the mechanical properties of the surrounding rock, control the deformation of the surrounding rock, and realize the double support function of the bolt and grouting .

In order to solve the above-mentioned technical problems, the liquid carbon dioxide blasting anti-reflection grouting composite anchor provided by the present invention includes an anchor body and an expansion shell anchor head. A discharge head and a filling head detachably connected to the rear end of the liquid storage pipe, the discharge head is provided with a release pipeline connected to the inner cavity of the liquid storage pipe, and the outer wall is provided with a vent hole passing through the release pipeline; An energy-dissipating sheet is provided between the inner cavity of the liquid storage tube and the release pipeline; the expansion shell anchor head is connected to the front end of the energy-discharging head; the filling head is provided with a liquid filling hole that communicates with the inner cavity of the liquid storage tube and a valve for controlling the opening and closing of the liquid filling hole, and a heating element is arranged at the rear end of the inner chamber of the liquid storage tube.

Further, the expansion shell anchoring head includes a screw rod, a wedge nut and two corresponding expansion shell clips. One end of the screw is fixedly connected to the front end of the energy dissipation head, and the other end is connected between the two expansion shell clips. Pass through and screw-fit with the screw hole of the wedge nut. The wedge nut is provided with a wedge-shaped surface matched with the expansion shell clip. The two expansion shell clips are connected together through the tapered end cap at the front end.

Further, the outer surface of the expander clip is an inverted sawtooth-shaped conical surface, and the inverted sawtooth is arranged in a circumferential direction.

Further, the length and diameter of the anchor rod body are processed according to requirements, and the outer surfaces of the liquid storage pipe and the energy dissipation head are provided with trapezoidal threads.

In the liquid carbon dioxide blasting anti-reflection grouting composite bolt adopting the above-mentioned technical solution, a retaining ring with a backing plate is arranged at the rear end of the liquid storage pipe.

In the present invention, the filling head and the liquid storage pipe are connected by threads, and the surface of the liquid storage pipe body forms a trapezoidal thread, which is beneficial for the bolt to drill in a rotating manner and closely fit with the rock mass.

The support steps of the liquid carbon dioxide blasting antireflection grouting composite bolt are as follows:

1. Before the roadway surrounding rock bolting and grouting support reinforcement construction, the first choice is to carry out engineering geological survey, rock physical and mechanical parameter test and roadway loose circle test to obtain rock physical and mechanical parameters, structural surface development status, roadway loose circle range and other basic parameters;

2. Combined with the properties of the surrounding rock, determine the position of the vent hole of the composite bolt according to the corresponding blasting theory calculation. After determining the position and depth of the vent hole, further determine the depth of the anchor hole and the total length of the composite bolt. The diameter of the composite bolt is generally taken as 30 -45mm; The bolt body can be equipped with energy-discharging heads with different arrangement angles and quantities of vent holes according to the actual cracking direction, and the position of the vent holes can be adjusted as needed;

3. When constructing anchor holes with a diameter smaller than the anchor rod, the composite anchor rod is drilled along the anchor hole to ensure that the liquid storage pipe and the energy discharge head are coupled with the anchor hole wall to increase friction; the expansion shell anchor head rotates the anchor rod body Move the wedge nut to one end of the filling head, through the wedging action of the wedge nut, the expansion shell anchor head is forced to open, embedded in the hole wall, and the anchor rod is fixed in the rock mass, and the liquid storage pipe is reinforced by the backing plate and retaining ring at the end , realizing prestressing on the bolt and forming radial resistance to the rock mass;

4. After the anchor bolt is fixed, the liquid carbon dioxide is filled through the filling head. The filling amount is reasonably determined according to the blasting pressure value required for induced blasting on the basis of the physical and mechanical properties of the rock mass and the quality classification of the surrounding rock, so as to ensure that The integrity of the rock is not damaged;

5. Turn on the power supply of the heating element, so that the liquid carbon dioxide is rapidly converted from a liquid state to a gaseous state, and the high-energy (pressure) airflow expands to cause the energy release sheet to open, and then it is discharged from the vent hole of the energy release head to achieve the effect of inducing cracking and induce cracking After the completion, after a certain period of crack expansion and development of anti-reflection stage, the filling head and heating element are disassembled, and the grout is pumped into the liquid storage pipe through the grouting pump and enters the anchor hole and rock mass crack through the vent hole of the discharge head. Until it fills the crack structure surface in the rock body, the double support of anchoring and grouting can be achieved.

The beneficial effects of the present invention are: using liquid carbon dioxide high-pressure gas blasting to replace traditional explosive blasting, while ensuring that the surrounding rock mass is not damaged as a whole, it can induce cracking in a certain depth of rock mass, so that the orientation of the crack zone is uniform Expansion, effectively expanding the range of fissure zones in the rock body, creating more favorable conditions for grouting reinforcement; at the same time, directly using carbon dioxide blasting pipes as grouting channels to implement rock mass grouting reinforcement, realizing the organic combination of induced blasting and grouting; using carbon dioxide For blasting, the arrangement angle of vent holes and the number of energy-dissipating heads can be artificially arranged according to the nature of the surrounding rock and the characteristics of the structural surface to achieve the effect of energy-concentrated perforation blasting; the traditional explosive blasting is replaced by physical explosion, and the explosion is pollution-free and has no treatment The danger of dumb guns and blind guns is eliminated, and the operation is simple, the safety is greatly improved, and the effect of anchor injection double support is effectively improved.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the schematic structural view of the expansion shell anchoring head in the present invention;

Fig. 3 is a cross-sectional schematic diagram of the energy dissipation head in the present invention;

Fig. 4 is the blasting construction schematic diagram of using the present invention to carry out roadway surrounding rock support;

Fig. 5 is the grouting construction schematic diagram of using the present invention to carry out roadway surrounding rock support;

Among them: 1-filling head; 2-movable pin; 3-backing plate; 4-liquid storage pipe; 5-energy discharge head; 6-vent hole; 7-screw; Nut; 10-dissipating sheet; 11-heating element; 12-retaining ring; 13-valve; 14-filling hole; 15-anchor hole; 16-rock crack; 17-grouting pump; ; 19-tapered end cap.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1 to 5, a liquid carbon dioxide blasting anti-reflection grouting composite anchor includes an anchor body and an expansion shell anchor head. The anchor body includes a liquid storage tube 4 fixedly connected to the liquid storage tube 4 The energy-discharging head 5 at the front end and the filling head 1 detachably connected to the rear end of the liquid storage pipe 4, the energy-discharging head 5 is provided with a release pipeline 18 communicating with the inner cavity of the liquid storage pipe 4, and the outer wall is provided with a through-hole The exhaust hole 6 of the above-mentioned release pipeline; an energy-dissipating piece 10 is provided between the inner cavity of the liquid storage pipe and the release pipeline 18; specifically, the energy-discharging head 5 rotates in the liquid storage pipe 4, and passes through The positioning ring formed by protruding on the inner wall of the liquid storage pipe 4 is positioned, the energy dissipation sheet 10 is located between the positioning ring and the energy dissipation head 5, and the expansion shell anchoring head is connected to the front end of the energy dissipation head 5; The filling head 1 is provided with a liquid filling hole 14 communicating with the inner chamber of the liquid storage tube and a valve 13 for controlling the opening and closing of the liquid filling hole 14 , and a heating element 11 is provided at the rear end of the inner cavity of the liquid storage tube.

Specifically, the expansion shell anchoring head includes a screw rod 7, a wedge nut 9 and expansion shell clips 8 correspondingly arranged on two petals. The shell clamps 8 pass through and are screwed with the screw holes of the wedge nut 9. The wedge nut 9 is provided with a wedge-shaped surface that matches the expansion shell clamp 8. The two-petal expansion shell clamp 8 passes through the front end The tapered end caps 19 of the wedge nut 9 are connected together, and the distance between the two wedge-shaped surfaces of the wedge nut 9 gradually decreases from front to back. Preferably, the outer surface of the expander clip 8 is an inverted serrated tapered surface , the inverted serrations are arranged in a circumferential direction, thereby increasing the frictional force between the anchoring head of the expansion shell and the hole wall of the rock formation, thereby increasing the anchoring force of the bolt.

Wherein, the length and diameter of the anchor rod body are processed as required, and trapezoidal threads are arranged on the outer surfaces of the liquid storage pipe 4 and the energy-dissipating head 5, thereby facilitating the drilling of the anchor rod.

In order to facilitate the adjustment of the direction of the vent hole 6 in the anchor hole, the filling head 1 is provided with a score line corresponding to the position of the vent hole 6 .

In the above technical solution, a retaining ring 12 with a backing plate 3 is provided at the rear end of the liquid storage pipe 4, and the shown retaining ring 12 is positioned and installed on the liquid storage pipe 4 by the movable pin 2.

The support steps of the liquid carbon dioxide blasting antireflection grouting composite bolt are as follows:

1. Before the roadway surrounding rock bolting and grouting support reinforcement construction, the first choice is to carry out engineering geological survey, rock physical and mechanical parameter test and roadway loose circle test to obtain rock physical and mechanical parameters, structural surface development status, roadway loose circle range and other basic parameters;

2. Combined with the nature of the surrounding rock, the position of the vent hole 6 in the composite anchor is determined according to the corresponding blasting theory calculation. After determining the position and depth of the vent hole 6, further determine the depth of the anchor hole and the total length of the composite anchor. The diameter is taken as 35mm; the bolt body can be selected according to the actual direction of cracking induced by the energy-dissipating head with different arrangement angles and numbers of vent holes, and the position of the vent hole can be adjusted as required; in this embodiment, the energy-dissipating head 5 There are two rows of four prefabricated air vents 6 arranged vertically and symmetrically. The position of the vent hole 6 and the filling head 1 are marked correspondingly with the engraved line, so as to grasp the direction of the vent hole 6 in the rock body during installation of the composite bolt into the anchor hole and fixing process;

3. An anchor hole 15 with a diameter smaller than the anchor rod is constructed in the surrounding rock of the roadway, and the composite anchor rod is drilled along the anchor hole to ensure the coupling between the anchor rod body and the anchor hole wall and increase the friction; The anchor rod body moves the wedge nut 9 to the direction of the filling head 1, and through the wedging action of the wedge nut 9, the expansion shell clip 8 is forced to open and embedded in the hole wall, so that the anchor rod is fixed in the rock mass; the liquid storage pipe 4 passes through The backing plate 3 and the retaining ring 12 at the tail end are reinforced to apply prestress to the bolt and form radial resistance to the rock mass;

4. After the bolt is fixed, fill a certain amount of liquid carbon dioxide into the liquid storage pipe 4 through the liquid filling hole 14 on the filling head 1. The filling amount is based on the physical and mechanical properties of the rock mass and the quality classification of the surrounding rock. Reasonably determine the blast pressure value required for induced blasting to ensure that the integrity of the surrounding rock is not damaged;

5. Turn on the power supply of the heating element 11, so that the liquid carbon dioxide is rapidly converted from a liquid state to a gaseous state, and the high-energy (pressure) airflow expands to cause the energy release sheet 10 to open, and then it is discharged from the vent hole 6 of the energy release head 5 to realize the induced cracking effect ; After the induced cracking is completed, the grouting can be carried out after a certain period of crack expansion and development and enhancement stage. At this time, the filling head 1 and the heating element 11 are disassembled, and the slurry is pumped into the liquid storage pipe 4 through the grouting pump 17 and enters the anchor hole 15 and the rock mass fissure 16 through the vent hole 6 of the energy discharge head 5 until the grout is filled. The structural surface of the crack in the body achieves the double support of anchoring and injection.

The above is only a description of specific implementation examples of the present invention, and cannot limit the scope of protection of the rights of the present invention once. All changes, modifications, additions or substitutions made within the essential scope of the invention shall also belong to the protection scope of the present invention.

Claims (3)

1. The utility model provides a liquid carbon dioxide blasting anti-reflection slip casting composite anchor, includes the stock body of rod and expands shell anchor head, its characterized in that: the anchor rod body comprises a liquid storage pipe, an energy discharging head fixedly connected to the front end of the liquid storage pipe and a filling head detachably connected to the rear end of the liquid storage pipe, a release pipeline communicated with the inner cavity of the liquid storage pipe is arranged in the energy discharging head, and an exhaust hole penetrating through the release pipeline is arranged on the outer wall of the energy discharging head; an energy release sheet is arranged between the inner cavity of the liquid storage pipe and the release pipeline; the expansion shell anchoring head is connected to the front end of the energy release head; the filling head is provided with a liquid filling hole communicated with the inner cavity of the liquid storage tube and a valve for controlling the liquid filling hole to be opened and closed, and the rear end of the inner cavity of the liquid storage tube is provided with a heating element;

the expansion shell anchoring head comprises a screw rod, a wedge-shaped nut and expansion shell clamping pieces which are correspondingly arranged, one end of the screw rod is fixedly connected with the front end of the energy release head, the other end of the screw rod penetrates through the space between the two expansion shell clamping pieces and is in threaded connection with a screw hole of the wedge-shaped nut, the wedge-shaped nut is provided with a wedge-shaped surface matched with the expansion shell clamping pieces, and the two expansion shell clamping pieces are connected together through a conical end cap at the front end; the distance between the two wedge faces of the wedge nut gradually becomes smaller from front to back;

the outer surface of the expansion shell clamping piece is an inverted saw-tooth-shaped conical surface, and the inverted saw teeth are distributed in a circumferential direction;

the outer surfaces of the liquid storage pipe and the energy discharging head are provided with trapezoidal threads.

2. The liquid carbon dioxide blasting anti-reflection grouting composite anchor rod according to claim 1, wherein: and the filling head is provided with a scribing line corresponding to the position of the exhaust hole.

3. The liquid carbon dioxide blasting anti-reflection grouting composite anchor rod according to claim 1 or 2, wherein: the rear end of the liquid storage pipe is provided with a baffle ring with a backing plate.