A construction method for installing an anchor rod by using a self-dissolving bagged mortar roll

Abstract

This invention discloses a construction method for installing anchor bolts using self-dissolving bagged mortar rolls, comprising the following steps: 1. Determining the cross-sectional radius of the self-dissolving bagged mortar roll; 2. Determining the specifications of the self-dissolving bag; 3. Preparing the self-dissolving bagged mortar roll and inserting it into the drilled hole; 4. Installing the anchor bolt. The self-dissolving bag of this invention is a specially customized water-soluble self-dissolving bag based on the different actual conditions inside each engineering hole. The dissolution time and rate of the self-dissolving mortar bag inserted into the anchor bolt hole are controlled by the dissolution temperature of the self-dissolving bag. The self-dissolving bag can effectively disperse in the mortar, improve the early strength development of the mortar, enhance the durability and impermeability of the mortar, effectively reduce the porosity inside the mortar, and improve the density of the mortar. There is no fiber bag residue in the anchor bolt hole, and it will not form adverse factors that hinder the bonding effect between the mortar and the inner wall of the hole, or between the mortar and the anchor bolt. The self-dissolving bag has no effect on the adhesion ability of the mortar.

Description

Technical Field

[0001] This invention belongs to the field of anchor installation technology, specifically relating to a construction method for installing anchors using self-dissolving bagged mortar rolls. Background Technology

[0002] In the construction of underground engineering projects for hydropower stations, the installation of mortar anchors is a crucial step, with vertical and inclined anchor installations being particularly challenging. Ordinary mortar anchors are full-length bonded anchors with a very simple structure. Construction involves drilling holes, inserting grouting pipes while simultaneously injecting grout, then inserting threaded reinforcing bars (the length depending on the surrounding rock), and finally welding them to a steel frame or steel grating. Ordinary mortar anchors have significant advantages: firstly, they are inexpensive, with relatively low costs and simple construction, making them economically attractive; secondly, their installation is quick due to the simple manufacturing process, requiring no complex equipment or specialized skills. However, ordinary mortar anchors also have the following drawbacks: Firstly, the fullness of grout injection in ordinary anchor holes is subject to human error, which may affect the anchoring effect, especially in anchors longer than 3.0 meters. This could lead to a significant discrepancy between the actual effective anchoring zone and the design requirements. Secondly, grouting at the large inclination angle of the arch crown is relatively difficult due to the weight of the mortar and the adhesion of the borehole wall. After grouting, the mortar in the anchor hole is easily lost. Insufficient grout fullness and exposed reinforcing steel not only fail to restrain the deformation of the surrounding rock but also make the anchor susceptible to groundwater erosion, leading to corrosion of the steel rod and ultimately its failure, affecting the anchor's durability. Furthermore, it fails to meet the standard requirements for grout density, resulting in substandard anchor construction quality. Thirdly, it has poor adaptability: in weak and fractured rock formations and other unfavorable strata, borehole collapse is common after drilling, and ordinary mortar anchors are less capable of handling this. Fourthly, there is no guarantee for anchor centering. Due to the weight of the anchor and the fluidity of the mortar, under inclined conditions within the anchor hole, the anchor will lean against and adhere tightly to one side of the borehole wall, resulting in eccentricity and an inability to guarantee an effective and uniform mortar protective layer, leading to poor anchor durability. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a construction method for installing anchor rods using self-dissolving bagged mortar rolls, which addresses the shortcomings of the prior art.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a construction method for installing anchor bolts using self-dissolving bagged mortar rolls, characterized in that the construction method includes the following steps:

[0005] Step 1: Determine the cross-sectional radius of the self-dissolving bagged mortar roll: According to the formula... Determine the cross-sectional radius r of the self-dissolving bagged mortar roll, where, Let be the radius of the borehole. The radius of the anchor bolt; the self-dissolving bagged mortar roll includes a self-dissolving bag and mortar filled inside the self-dissolving bag;

[0006] Step 2: Determine the specifications of the self-dissolving bag: The specifications of the self-dissolving bag include the dissolution temperature and the length of the self-dissolving bag; the length of the self-dissolving bag is determined based on the length of the drilled hole and the number of self-dissolving bags used; the dissolution temperature of the self-dissolving bag is determined based on the water dissolution rate and time of the self-dissolving bag, and thus the specifications of the self-dissolving bag are determined.

[0007] Step 3: Prepare self-dissolving bagged mortar rolls and load them into the borehole: Fill the prepared mortar into self-dissolving bags and seal the bag openings. Then, load the sealed self-dissolving bagged mortar rolls into the borehole according to the required quantity. Sealing plates are connected to the outer sides of multiple self-dissolving bagged mortar rolls in the borehole, as well as the outer side of the outermost self-dissolving bagged mortar roll in the borehole. Multiple sealing plates are used to position the anchor rods and seal the holes. A through hole is opened in the center of the sealing plate for the anchor rods to pass through.

[0008] Step 4: Install the anchor rod: Rotate the anchor rod and pass it through multiple through holes. After passing through multiple through holes, the rotating anchor rod will pass through multiple self-dissolving bags in sequence until it is inserted to the bottom of the hole. Then rotate it out 30-50mm. When the steel anchor rod is inserted, under the combined action of frictional heat, hydration heat of mortar and ambient temperature, the self-dissolving bags will begin to dissolve in the mortar, thus completing the anchoring construction of the anchor rod.

[0009] The above-mentioned construction method for installing anchor bolts using self-dissolving bagged mortar rolls is characterized in that: the self-dissolving bag is a polyvinyl alcohol self-dissolving bag.

[0010] The above-mentioned construction method for installing anchor bolts using self-dissolving bagged mortar rolls is characterized in that: the dominant factors corresponding to the dissolution temperature of the self-dissolving bag include the ambient temperature inside the tunnel, the temperature of the mixing water, the frictional heat generated when the steel anchor bolt is inserted, and the heat of hydration of the mortar.

[0011] The above-mentioned construction method for installing anchor bolts using self-dissolving bagged mortar rolls is characterized in that: in step three, the mortar includes cement, sand, and water, and the mass ratio of the mortar is: cement: sand: water = 1:(1~1.5):(0.45~0.5); the mixed mortar is filled into self-dissolving bags using a mortar bagging machine, sealed using a mortar bag sealing machine, and then the sealed self-dissolving bagged mortar rolls are filled into the borehole according to the required quantity.

[0012] The above-mentioned construction method for installing anchor bolts using self-dissolving bagged mortar rolls is characterized in that: the mortar also includes active materials containing silicon and aluminum or a designed amount of mixed materials, wherein the mixed materials include hydrated lime powder or gypsum powder.

[0013] The above-mentioned construction method for installing anchor bolts using self-dissolving bagged mortar rolls is characterized in that: the number of sealing plates is 3 to 5, the diameter of the through hole is 2 mm larger than the diameter of the anchor bolt, and the diameter of the sealing plate is 1 to 2 mm smaller than the diameter of the drill hole.

[0014] The above-mentioned construction method for installing anchor bolts using self-dissolving bagged mortar rolls is characterized in that: the anchor bolts are fed into the borehole using an anchor bolting machine or a pneumatic anchor bolting drill.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The self-dissolving bag of this invention is a specially customized water-soluble self-dissolving bag based on the different actual conditions inside each engineering hole. The dissolution time and speed of the self-dissolving mortar bag inserted into the anchor bolt hole are controlled by the dissolution temperature of the self-dissolving bag. The self-dissolving bag is a fiber bag made of water-soluble PVA solution through spinning, stretching, drying and heat treatment under dry heat conditions. It has good solubility in water and can be effectively dispersed in mortar. It can also improve the early strength development of mortar, enhance the durability and impermeability of mortar, effectively reduce the porosity inside the mortar, and improve the density of mortar. There is no fiber bag residue in the anchor bolt hole, and it will not form an adverse factor that hinders the bonding effect between mortar and the inner wall of the hole, or between mortar and anchor bolt. The self-dissolving bag has no effect on the adhesion ability of mortar, which is convenient for widespread use.

[0017] 2. The self-dissolving bagged mortar roll of the present invention includes a self-dissolving bag and mortar filled in the self-dissolving bag. The use of self-dissolving bagging reduces mortar outflow and overflow, and ensures the compactness of the mortar filling in the anchor bolt hole.

[0018] 3. The method of the present invention is simple. When filling the hole with self-dissolving bagged mortar, 3 to 5 inner sealing plates are placed at the outermost bagged mortar roll and inside the hole along with the mortar roll. The sealing plate ring can effectively prevent mortar from overflowing, greatly improve the mortar density, solve the problem of low density in existing construction, and at the same time serve as a centering positioning device for the anchor rod in the hole. While improving the grouting density of the anchor rod, it can also simultaneously correct the eccentricity of the anchor rod body, ultimately improving the overall anchor rod construction quality.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method of the present invention.

[0021] Figure 2 This is a construction layout diagram for the present invention.

[0022] Figure 3 for Figure 2 The left view.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1—Drill hole; 2—Self-dissolving bag; 3—Mortar; 4—Sealing plate; 5—Through hole. Detailed Implementation

[0025] like Figures 1 to 3 As shown, the present invention provides a construction method for installing anchor bolts using self-dissolving bagged mortar rolls, comprising the following steps:

[0026] Step 1: Determine the cross-sectional radius of the self-dissolving bagged mortar roll: According to the formula... Determine the cross-sectional radius r of the self-dissolving bagged mortar roll, where, Let the radius of borehole 1 be . The radius of the anchor bolt is given. The self-dissolving bagged mortar roll includes a self-dissolving bag 2 and mortar 3 filled inside the self-dissolving bag 2.

[0027] Step 2: Determine the specifications of the self-dissolving bag: The specifications of the self-dissolving bag include the dissolution temperature and length of the self-dissolving bag 2; the length of the self-dissolving bag 2 is determined based on the length of the drill hole 1 and the number of self-dissolving bags 2 used; the dissolution temperature of the self-dissolving bag 2 is determined based on the water dissolution rate and time of the self-dissolving bag 2, and thus the specifications of the self-dissolving bag are determined.

[0028] Step 3: Prepare self-dissolving bagged mortar rolls and load them into the borehole: Fill the prepared mortar 3 into the self-dissolving bag 2 and seal the bag opening. Then, load the sealed self-dissolving bagged mortar rolls into the borehole 1 according to the required quantity. The outer sides of the multiple self-dissolving bagged mortar rolls in the borehole 1 and the outer side of the outermost self-dissolving bagged mortar roll in the borehole 1 are connected to sealing plates 4. Multiple sealing plates 4 are used to position the anchor rods and seal the holes. The sealing plates 4 have through holes 5 at their center for the anchor rods to pass through.

[0029] Step 4: Install the anchor rod: Rotate the anchor rod and pass it through multiple through holes 5. After passing through multiple through holes 5, the rotating anchor rod passes through multiple self-dissolving bags 2 in sequence until it is inserted to the bottom of the hole. Then rotate it out 30-50mm. When the steel anchor rod is inserted, under the combined action of frictional heat, hydration heat of mortar and ambient temperature, the self-dissolving bags 2 begin to dissolve in the mortar, thus completing the anchoring construction of the anchor rod.

[0030] It should be noted that the self-dissolving bagged mortar roll includes a self-dissolving bag and the mortar inside the bag. The use of self-dissolving bags reduces mortar outflow and overflow, ensuring the compactness of the mortar filling in the anchor bolt holes. The self-dissolving bag is a specially customized water-soluble self-dissolving bag based on the specific conditions of each engineering hole. The dissolution time and rate of the self-dissolving mortar bag inside the anchor bolt hole are controlled by the dissolution temperature of the bag. The self-dissolving bag is a fiber bag made from water-soluble PVA solution through spinning, stretching, drying, and heat treatment under dry heat conditions. It has good solubility in water and can effectively disperse in the mortar, improving the early strength development of the mortar, enhancing its durability and impermeability, effectively reducing internal porosity, and increasing the compactness of the mortar. There is no fiber bag residue inside the anchor bolt hole, preventing it from affecting the mortar's structure. The self-dissolving bag creates unfavorable factors that hinder the bonding effect between the grout and the inner wall of the hole, and between the grout and the anchor rod. However, the self-dissolving bag does not affect the adhesion ability of the grout. When filling the hole with the self-dissolving bagged grout, 3 to 5 inner sealing plates are placed at the outermost bag opening and inside the hole along with the grout roll. The sealing plate ring can effectively prevent grout overflow and backflow. The density of the anchor rod can be judged by observing the amount of grout overflowing from the hole opening, which greatly improves the grout density and solves the problem of low density in the current construction. At the same time, as a centering positioning device for the anchor rod in the hole, it can simultaneously correct the eccentricity of the anchor rod body while improving the grouting density of the anchor rod, ultimately improving the overall anchor rod construction quality.

[0031] In this embodiment, the self-dissolving bag 2 is a polyvinyl alcohol self-dissolving bag.

[0032] It should be noted that self-dissolving bags are mortar bags specially made of water-soluble polyvinyl alcohol (PVA). These specially made water-soluble PVA bags not only have certain strength and elongation, but also good acid and alkali resistance. Moreover, they can dissolve in water at ideal temperatures. After dissolving, they are odorless and non-toxic, and the aqueous solution is colorless and transparent. They can decompose naturally in a short time, without causing any pollution to the environment. They are 100% green and environmentally friendly products.

[0033] Polyvinyl alcohol (PVA) has good solubility in water and can be effectively dispersed in mortar. PVA can effectively control the setting time of mortar, preventing it from setting too quickly, thus improving its workability during construction. In addition, PVA can improve the early strength development of mortar, enhance its durability and impermeability, effectively reduce the porosity of the mortar, and increase its density. At the same time, PVA has good water resistance and chemical stability, which can improve the long-term performance of mortar.

[0034] In this embodiment, the dominant factors corresponding to the dissolution temperature of the self-dissolving bag 2 include the ambient temperature inside the tunnel, the temperature of the mixing water, the frictional heat generated when the steel anchor is inserted, and the heat of hydration of the mortar.

[0035] In this embodiment, in step three, the mortar 3 includes cement, sand and water, and the mass ratio of mortar 3 is: cement: sand: water = 1: (1~1.5): (0.45~0.5); the mixed mortar is loaded into self-dissolving bags 2 through a mortar bag loading machine, sealed with a mortar bag sealing machine, and then the sealed self-dissolving bagged mortar rolls are loaded into the drill hole 1 according to the required quantity.

[0036] In this embodiment, the mortar 3 also includes active materials containing silicon and aluminum or a designed amount of mixed materials, the mixed materials including hydrated lime powder or gypsum powder.

[0037] It should be noted that the mortar used in self-dissolving bagged mortar rolls requires the addition of some active materials containing silicon and aluminum, or a certain amount of mixed materials, such as hydrated lime powder and gypsum powder, during the mixing process to improve the quality and stability of the anchor mortar and meet the technical requirements for its consistency, fluidity, segregation, water retention, and shrinkage. When hydrated lime powder comes into contact with water, a chemical reaction occurs to generate calcium hydroxide. This process releases a large amount of heat, which helps to increase the overall temperature of the mortar roll and allows the PVA fiber cloth mortar bag to dissolve fully.

[0038] In this embodiment, the number of sealing plates 4 is 3 to 5, the diameter of the through hole 5 is 2 mm larger than the diameter of the anchor rod, and the diameter of the sealing plate 4 is 1 to 2 mm smaller than the diameter of the drill hole 1.

[0039] In this embodiment, the anchor bolt is inserted into the borehole 1 using an anchor bolting machine or a pneumatic anchor bolting drill.

[0040] When using this invention, mortar is mixed, bagged, sealed, and inserted into the hole at the anchor bolt construction site. The process is timely and adjusted according to the anchor bolt construction situation, avoiding material waste by mixing and using it immediately. Small mixing equipment, a dedicated handheld mortar bagging machine, a handheld mortar roll sealing machine, a self-dissolving bagged mortar roll insertion tool, and a steel bar anchor bolt extrusion device are selected.

[0041] The construction method of filling the borehole 1 with self-dissolving bagged mortar rolls can also provide some support or replenishment when encountering borehole collapse or borehole wall deformation, and the effect is good.

[0042] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, or equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A construction method for installing anchor bolts using self-dissolving bagged mortar rolls, characterized in that, The construction method includes the following steps: Step 1: Determine the cross-sectional radius of the self-dissolving bagged mortar roll: According to the formula... Determine the cross-sectional radius r of the self-dissolving bagged mortar roll, where, Let the radius of the borehole (1) be , For the radius of the anchor bolt, the self-dissolving bagged mortar roll includes a self-dissolving bag (2) and mortar (3) filled in the self-dissolving bag (2); Step 2: Determine the specifications of the self-dissolving bag: The specifications of the self-dissolving bag include the dissolution temperature of the self-dissolving bag (2) and the length of the self-dissolving bag (2); the length of the self-dissolving bag (2) is determined according to the length of the drill hole (1) and the number of self-dissolving bags (2) used; the dissolution temperature of the self-dissolving bag (2) is determined according to the water dissolution rate and time of the self-dissolving bag (2), and then the specifications of the self-dissolving bag are determined. Step 3: Prepare self-dissolving bagged mortar rolls and load them into the borehole: Load the mixed mortar (3) into the self-dissolving bag (2) and seal the bag opening. Then load the sealed self-dissolving bagged mortar rolls into the borehole (1) according to the required quantity. The outer sides of the multiple self-dissolving bagged mortar rolls in the borehole (1) and the outer side of the outermost self-dissolving bagged mortar roll in the borehole (1) are connected to sealing plates (4). Multiple sealing plates (4) are used to position the anchor rods and seal the holes. The center of the sealing plate (4) is provided with a through hole (5) for the anchor rods to pass through. Step 4, Install the anchor rod: Rotate the anchor rod and pass it through multiple through holes (5). After the rotating anchor rod passes through multiple through holes (5), it passes through multiple self-dissolving bags (2) in sequence until it is inserted to the bottom of the hole. Then rotate it out 30-50mm. When the steel anchor rod is inserted, under the combined action of frictional heat, hydration heat of mortar and ambient temperature, the self-dissolving bags (2) begin to dissolve in the mortar, thus completing the anchoring construction of the anchor rod. The self-dissolving bag (2) is a polyvinyl alcohol self-dissolving bag.

2. The construction method for installing anchor bolts using self-dissolving bagged mortar rolls according to claim 1, characterized in that: The dominant factors corresponding to the dissolution temperature of the self-dissolving bag (2) include the ambient temperature inside the tunnel, the temperature of the mixing water, the frictional heat generated when the steel anchor rod is inserted, and the heat of hydration of the mortar.

3. The construction method for installing anchor bolts using self-dissolving bagged mortar rolls according to claim 1, characterized in that: In step three, the mortar (3) includes cement, sand and water, and the mass ratio of the mortar (3) is: cement: sand: water = 1: (1~1.5): (0.45~0.5). The mixed mortar is loaded into a self-dissolving bag (2) through a mortar bag loading machine, sealed with a mortar bag sealing machine, and then the sealed self-dissolving bag mortar rolls are loaded into the borehole (1) according to the required quantity.

4. The construction method for installing anchor bolts using self-dissolving bagged mortar rolls according to claim 3, characterized in that: The mortar (3) also includes active materials containing silicon and aluminum or a designed amount of mixed materials, including hydrated lime powder or gypsum powder.

5. A construction method for installing anchor bolts using self-dissolving bagged mortar rolls according to claim 1, characterized in that: The number of sealing plates (4) is 3 to 5. The diameter of the through hole (5) is 2 mm larger than the diameter of the anchor rod, and the diameter of the sealing plate (4) is 1 to 2 mm smaller than the diameter of the drill hole (1).

6. A construction method for installing anchor bolts using self-dissolving bagged mortar rolls according to claim 1, characterized in that: The anchor bolt is inserted into the borehole (1) using an anchor bolting machine or a pneumatic anchor bolting drill.

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