CN103147777B - Pumping paste prestress full bolting anchor rod/cable supporting method - Google Patents

Abstract

The invention relates to a pumping paste prestress full bolting anchor rod/cable supporting method. Two kinds of paste grouting liquid with different solidification time are adopted as anchoring agents, a flexible pipe is inserted into a drilling hole, rapid hardening paste serous fluid is filled into the drilling hole through the flexible pipe, then, delayed coagulation paste serous fluid is filled into the drilling hole, an anchor rod/cable is inserted into the drilling hole, the exposed section of the anchor rod/cable is sequentially provided with an upper tray and a wedge-shaped anchor tool, after the rapid hardening paste serous fluid is solidified, a tensioning instrument tensions the outer exposed section of the anchor rod/cable, the pretightening force is exerted in the full-length range of the anchor rod/cable, and the full-length anchoring is formed after the delayed coagulation paste serous fluid is solidified. The pumping paste prestress full bolting anchor rod/cable supporting method has the advantages that the anchoring problem of deep holes can be solved, the control can be realized through regulating the addition quantity of rapid hardening agents, the inner and outer sections of the anchor rod/cable are respectively anchored by fast and slow paste serous fluid, the pretightening force and the full-length anchoring are organically combined, the construction process is simple, the control effect of the anchor rod/cable on the surrounding rock deformation is effectively improved, and the supporting problems of high-ground stress, high-dynamic-pressure and great-deformation roadway of the deep well are solved.

Description

Pumping paste prestressed full anchor bolt/cable support method

technical field

The invention relates to the control and support technology of surrounding rocks in coal mine roadways, in particular to a pumping paste prestressed full-bolt bolt/cable support method suitable for roadway surrounding rocks.

Background technique

In geotechnical and mining engineering, bolt support is a surrounding rock control technology with two functions of support and reinforcement. Compared with frame support, it has been widely used in countries all over the world for its remarkable technical and economic benefits. Rods as the basic support form include single anchors, anchor beams (belts), anchor beams (belts) nets, and anchors and anchors/cables. The bolt support system has developed rapidly and is widely used at home and abroad. In coal mine roadway support, it has become one of the essential key technologies for coal mines to achieve high production and high efficiency.

Prestressed bolt/cable is a new type of support technology developed on the basis of bolt support with large anchorage depth, high bearing capacity, and large pre-tightening force, which can mobilize surrounding rock in a wide range Under difficult conditions (such as large-section roadways and intersections, compound broken roof roadways, geological structure influence zones, etc.), the use of bolt/cable reinforcement technology can ensure the stability and safety of surrounding rock, and has become a The main means of reinforcement in difficult roadways.

With the increasing demand for energy and increasing mining intensity, shallow resources are decreasing day by day. Many mines at home and abroad have entered the state of deep resource mining. In the complex environment of coupling, the deformation of the roadway is large, the deformation time is long, the surrounding rock is severely broken, and the failure of anchor rods and cables is frequent, so the maintenance of the roadway is very difficult. Traditional prestressed anchor rods/cables generally use resin coils for end anchorage. Although this method has high bonding strength, fast curing, and high safety and reliability, it cannot achieve prestressed full-length anchorage, so that it cannot be anchored under high stress and large deformation conditions. It is prone to stress concentration and fracture. At present, the grouting method is generally used to realize the full-length anchorage of the bolt/cable, but there are problems such as complicated hole sealing process, serious running and grout leakage, and poor anchoring effect. The above phenomenon seriously affects the control effect of bolt/cable support on the surrounding rock, especially it cannot solve the support problems of deep weak broken, dynamic pressure and large deformation roadways.

Contents of the invention

Technical problem: The purpose of this invention is to overcome the deficiencies in the prior art and provide a simple, easy-to-construct, and effective pumping paste prestressed full-bolt/cable support method.

Technical solution: The pumping paste prestressed full anchor bolt/cable support method of the present invention includes drilling and cleaning holes on the roadway rock surface, and the steps are as follows:

a, prepare two kinds of quick-setting paste slurry and slow-setting paste slurry with different setting times;

b. Insert a hose connected to the grouting pump in the borehole on the rock face of the roadway until the bottom of the borehole;

c. Calculate the amount of paste grout required for prestressed full anchorage according to the diameter and anchorage length of the borehole, anchor rod/cable, and set the length of the anchorage section of the quick-setting paste grout to 1/6 of the depth of the borehole. The length of the anchoring section of the gelled grout is 5/6 of the drilling depth;

d. Turn on the grouting pump and inject the quick-setting paste slurry into the drill hole through the hose, and then inject the slow-setting paste slurry into the drill hole. While injecting the two kinds of paste slurry, slowly pull out the hose, so that Quick-setting paste slurry and slow-setting paste slurry fill the gap of the extraction hose;

e. Insert the anchor rod/cable into the drill hole, fill the annular gap around the anchor rod/cable with the extruded quick-setting paste slurry and slow-setting paste grout, and install trays on the exposed sections of the anchor rod/cable in turn , Wedge anchorage;

f. After the quick-setting paste slurry is solidified, use a tensioner to tension the exposed section of the anchor rod/cable, and apply a pre-tightening force within the entire length of the anchor rod/cable. After the slow-setting paste slurry is solidified, it will form Full length anchor.

The quick-setting paste slurry is configured by water, cement, anchoring additive, and quick-setting agent according to the mass ratio, wherein the mass ratio of water and cement is 0.25 ~ 0.35, and the anchoring additive is 3% ~ 5% of the amount of cement, The accelerator is 2%~3% of the cement content, and the setting time is 30min.

The retarded paste slurry is configured by water, cement and anchoring additives according to the mass ratio, wherein the mass ratio of water and cement is 0.25 ~ 0.35, the anchoring additive is 3% ~ 5% of the amount of cement, and the setting time is 6 Hours.

Beneficial effects: the invention uses two paste grouting fluids with different solidification times as the anchoring agent, which has good thixotropy and fluidity. The falling phenomenon can effectively avoid the problem of ordinary cement grout that is easy to leak. At the same time, the two paste grouts with different setting times have a sufficient setting time difference. After the quick-setting paste grout is solidified, the anchor/cable will be pre-tightened. , the slow-setting paste slurry will not solidify until the prestress is applied for a period of time. In this way, the pre-tightening force is combined with the full-length anchorage, which effectively improves the control effect of the bolt/cable on the deformation of the surrounding rock, and can solve the problem of deep wells and high ground. The support problem of roadway with strong stress, dynamic pressure and large deformation. The present invention can realize the full-length anchorage of prestressed bolts/cables, effectively improve the anchoring force of a single bolt/cable to the surrounding rock, thereby improving the support effect of the roadway and reducing the support density of the bolt/cable, compared with the traditional The end-anchor method allows greater deformation of the anchor body, which can solve the problem of deep well high-stress roadway support. The invention can also be used in surrounding rock support in other geotechnical, water conservancy and national defense projects. It can effectively solve the problem of limited anchorage length and inability to adapt to large deformation of roadway surrounding rock under deep high stress conditions existing in the existing bolt/cable support technology. The method is simple, easy to construct, good in anchoring effect, and has wide practicability. the

Description of drawings

Fig. 1 is the grouting process schematic diagram of the present invention;

Figure 2 is a schematic diagram of anchor rod/cable installation.

In the figure, 1-roadway rock surface, 2-drilling hole, 3-hose, 4-quick-setting paste slurry, 5-retarding paste slurry, 6-bolt/cable, 7-tray, 8-wedge anchor Tool.

Detailed ways

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings:

Embodiment 1,

(1) Mix the slurry according to the water and cement mass ratio of 0.25, respectively configure quick-setting paste slurry 4 and retarding paste slurry 5: take 2000 grams of cement, 500 grams of water, and 60 grams of FLOWCABLE anchoring additive produced by BASF, 40 grams of quick-setting agent, fully stirred to prepare quick-setting paste slurry 4; then take 2000 grams of cement, 500 grams of water, 60 grams of FLOWCABLE anchoring additive produced by BASF, and prepare retarded paste after completely stirring Serum 5;

(2) Drill hole 2 on the roadway rock surface 1, the diameter of the hole is 28mm, the depth of the hole is 6000mm, and the hole is cleaned;

(3) Insert the hose 3 with an inner diameter of 15mm and an outer diameter of 22mm into the bottom of the drill hole 2;

(4) According to the diameter and anchorage length of borehole 2, anchor rod/cable 6, calculate the amount of paste grout injection required for prestressed full anchorage by the following formula,

                                                                           

In the formula, s - paste slurry injection volume;

D - drilling diameter;

d — bolt/cable diameter;

l— anchor length

Take the borehole diameter as 28mm, the anchor rod/cable diameter as 22mm, the length of the quick-setting paste grout 4 anchor section as 1000mm, and the slow-setting paste slurry 5 anchor section as 5000mm in length,

Then the above formula calculates that the injection volumes of the quick-setting paste slurry 4 and the slow-setting paste slurry 5 are 0.24L and 1.18L respectively,

(5) Turn on the grouting pump, inject the prepared quick-setting paste slurry 4 and slow-setting paste slurry 5 into the borehole 2 through the hose 3, and control the injection volume through the metering device on the grouting pump; Inject the quick-setting paste slurry 4 into the borehole 2, and then inject the slow-setting paste slurry 5 into the borehole 2. While injecting the two kinds of paste slurry, slowly pull out the hose 3 to make the quick-setting paste slurry 4 , The retarded paste slurry 5 fills the gap in the extraction hose 3;

(6) Insert the anchor rod/cable 6 with a diameter of 22mm and a length of 6300mm into the drill hole 2, and the extruded quick-setting paste slurry 4 and retarded paste slurry 5 are filled in the annular gap around the anchor rod/cable 6 , install the tray 7 and the wedge anchor 8 in sequence on the exposed section of the anchor rod/cable 6;

(7) After the quick-setting paste slurry 4 is solidified for 30 minutes, use a tensioner to tension and pre-tighten the anchor rod/cable 6, apply a pre-tightening force within the entire length of the anchor rod/cable 6, and finally wait for the retarded paste After 6 hours of coagulation of the body serum 5, full-length anchoring was formed.

Embodiment 2,

It is basically the same as Example 1, and the similarities are omitted. The difference: the slurry is mixed according to the water and cement mass ratio of 0.3, and the quick-setting paste slurry 4 and the retarding paste slurry 5 are respectively prepared: take 2000 grams of cement, 600 grams of water, and 60 grams of FLOWCABLE anchoring additive produced by BASF , 40 grams of quick-setting agent, and get the required quick-setting paste slurry 4 after fully stirring; then take 2000 grams of cement, 600 grams of water, and 60 grams of FLOWCABLE anchoring additive produced by BASF, and stir completely to get Desired retarded cream slurry5.

Embodiment 3,

It is basically the same as Example 1, and the similarities are omitted. The difference: according to the water-cement mass ratio of 0.35 to mix the slurry, configure the fast and slow paste slurry 4 and 5 respectively: take 2000 grams of cement, 700 grams of water, 60 grams of FLOWCABLE anchoring additive produced by BASF, and 40 grams of quick-setting agent After fully stirring, the required quick-setting paste slurry 4 is obtained; then 2000 grams of cement, 700 grams of water, and 60 grams of FLOWCABLE anchoring additive produced by BASF are obtained, and the required retarding paste is obtained after fully stirring. Paste Serum5.

Claims (1)

1. the full anchor anchor pole/rope supporting method of pumping lotion prestressing force, is included in the upper boring (2) of tunnel scar (1), clear hole, it is characterized in that:

The rapid hardening lotion slurries (4) that a, preparation two kinds of setting times are different and slow setting lotion slurries (5); Described rapid hardening lotion slurries (4) are configured in mass ratio formed by water, cement, anchoring additive, accelerating admixtures, wherein the mass ratio of water and cement is 0.25 ~ 0.35, anchoring additive is 3% ~ 5% of cement amount, and accelerating admixture is 2% ~ 3% of cement amount, and setting time is 30min; Described slow setting lotion slurries (5) are configured in mass ratio formed by water, cement, anchoring additives, and wherein the mass ratio of water and cement is 0.25 ~ 0.35, and anchoring additive is 3% ~ 5% of cement amount, and setting time is 6 hours;

The flexible pipe (3) be connected with grouting pump is inserted, until the bottom of hole (2) in b, boring (2) on described tunnel scar (1);

C, calculate lotion slurries injection rate needed for the full anchoring of prestressing force according to boring (2), the diameter of anchor pole/rope (6) and anchorage length, set the length of rapid hardening lotion slurries (4) anchoring section as 1/6 of (2) degree of depth of holing, the length of slow setting lotion slurries (5) anchoring section is 5/6 of boring (2) degree of depth;

D, open grouting pump and first in boring (2), inject rapid hardening lotion slurries (4) by flexible pipe (3), and then slow setting lotion slurries (5) is injected in boring (2), two kinds of lotion slurries inject while slowly extracted out by flexible pipe (3), make rapid hardening lotion slurries (4), slow setting lotion slurries (5) fill up extract out flexible pipe (3) space;

E, by anchor pole/rope (6) insert boring (2) in, the rapid hardening lotion slurries (4) extruded, slow setting lotion slurries (5) are filled in anchor pole/rope (6) annulus around, load onto pallet (7), wedge shape ground tackle (8) successively at the revealed section of anchor pole/rope (6);

F, after rapid hardening lotion slurries (4) solidify, stretch-draw instrument is used to carry out stretch-draw to anchor pole/rope (6) revealed section, in anchor pole/rope (6) length range, apply pretightning force, after slow setting lotion slurries (5) solidify, namely form full length fastening.