Fractured stratum side slope anchoring device and construction method thereof

Abstract

The invention relates to the technical field of slope reinforcement, and discloses a fractured stratum slope anchoring device which comprises an anchor rod and a bearing plate, the bearing plate is connected to the end, close to the ground, of the anchor rod, and the bearing plate is used for fixing the anchor rod in a drill hole; the anchor rod is provided with a first through hole used for injecting grout, and the first through hole extends in the axial direction of the anchor rod. A plurality of second through holes which are formed in the axial direction of the anchor rod at intervals are formed in the peripheral surface of the anchor rod, extend in the direction perpendicular to the axis of the anchor rod and communicate with the first through holes; and barbs are arranged on the peripheral surface of the anchor rod, and are positioned on one side, close to the underground surface, of the second through hole. The anchoring device can enhance the anchoring performance. Meanwhile, the invention further provides a broken stratum side slope anchoring construction method.

Description

Technical Field

[0001] The present invention relates to the technical field of slope reinforcement, and in particular to a broken stratum slope anchoring device and a construction method thereof. Background Art

[0002] Slope anchoring projects in fractured strata often face challenges, including poor grouting effectiveness, insufficient anchoring force, difficulty in construction, and poor durability. Traditional grouting methods suffer from severe grout loss, making it difficult to form a uniformly consolidated structure. The anchor rods are not tightly bonded to the stratum, making them prone to slippage and failure. The drilling process is prone to hole collapse, resulting in low construction efficiency. Furthermore, long-term environmental influences such as groundwater and weathering degrade the anchoring performance. These issues severely hinder the stability of fractured strata slopes and the safety of the project.

[0003] In order to solve these problems, grouting can be carried out multiple times with better performance slurry to improve the anchoring performance. However, since the amount of grouting used in slope anchoring is large, using the same slurry for multiple grouting will increase the cost of slope anchoring and affect the company's profits.

[0004] The technical problem to be solved by the present invention is: how to improve the anchoring performance and reduce the cost when anchoring a broken stratum slope. Summary of the Invention

[0005] The main purpose of the present invention is to provide a slope anchoring device for broken strata, by arranging second through holes at intervals on the anchor rod and providing barbs near the second through holes, so that the slurry can diffuse to the nearby rock and soil and the barbs after flowing out of the second through holes, thereby ensuring the anchoring performance of the anchor rod and the slurry to the broken strata.

[0006] At the same time, a method for anchoring the slope of a broken stratum is also provided. Through secondary grouting, in the first grouting, a first slurry with lower fluidity is used to fill the large cracks in the broken stratum, and in the second grouting, a second slurry with higher fluidity is used to fill the micro cracks in the broken stratum. Since the cost of the second slurry is higher than that of the first slurry, this method can not only meet the crack grouting needs of the broken stratum, but also reduce the cost of the slurry.

[0007] To achieve the above objectives, the technical solutions adopted in this application are:

[0008] A broken stratum slope anchoring device comprises an anchor rod and a bearing plate, wherein the bearing plate is connected to one end of the anchor rod close to the ground, and the bearing plate is used to fix the anchor rod in a drilled hole; the anchor rod is provided with a first through hole for injecting slurry, and the first through hole extends along the axial direction of the anchor rod; the outer peripheral surface of the anchor rod is provided with a plurality of second through holes arranged at intervals along the axial direction of the anchor rod, the second through holes extend in a direction perpendicular to the axis of the anchor rod, and the second through holes are connected to the first through holes; the outer peripheral surface of the anchor rod is provided with barbs, and the barbs are located on the side of the second through hole close to the bottom surface of the ground.

[0009] Preferably, it also includes a pressure regulating unit, which includes a pressure sensor, a control valve and a controller; the control valve is connected to the end of the anchor rod close to the ground, and the control valve is used to control the grouting pressure when the external grouting port is grouting into the first through hole; the pressure sensor is used to detect the grouting pressure when the external grouting port is grouting into the first through hole; the controller is communicated with the pressure sensor and the control valve respectively.

[0010] Preferably, the diameter of the anchor rod is in the range of 25 to 40 mm; the diameter of the second through hole is in the range of 6 to 8 mm; the distance between the plurality of second through holes is in the range of 1 to 1.5 m; and the length of the barb is in the range of 20 to 30 mm.

[0011] At the same time, a method for anchoring a broken stratum slope is also provided, which is based on the above-mentioned broken stratum slope anchoring device and includes the following steps:

[0012] Step 1: Place the anchor rod in the drilled hole and fix it;

[0013] Step 2: injecting a first slurry into the first through hole, the first slurry flows out from the second through hole and diffuses into the surrounding rock and soil to form a primary grouting body, and the viscosity of the first slurry is 12-15s;

[0014] Step 3: After the first slurry is initially set, the second slurry is injected into the first through hole. The second slurry splits the primary grouting body from the second through hole and diffuses into the surrounding rock and soil to form a secondary grouting body. The viscosity of the second slurry is 8-10s;

[0015] The grouting pressure of the first slurry is lower than the grouting pressure of the second slurry.

[0016] This method uses secondary grouting. During the first grouting, the first slurry is used to fill the large cracks in the fractured formation. However, due to the poor fluidity of the first slurry, some microcracks remain unfilled. Therefore, during the second grouting, the second slurry is used to fill the microcracks in the fractured formation. Since the cost of the second slurry is higher than that of the first slurry, this method can significantly reduce the amount of second slurry used. Moreover, it does not affect the anchoring performance of the fractured formation, thereby increasing the company's profits.

[0017] It should be noted that the viscosity of the first slurry and the viscosity of the second slurry were measured using a Marsh viscometer;

[0018] In some embodiments, the viscosity of the first slurry is preferably 12s, 13s, 14s, or 15s, and the viscosity of the second slurry is preferably 8s, 9s, or 10s.

[0019] Preferably, the second slurry is composed of cement slurry and nano-silicon dioxide, and the mass ratio of cement slurry to nano-silicon dioxide is 100:2-5; the cement slurry is composed of cement, water glass and water, and the mass ratio of cement, water glass and water is 3-5:1:2.5.

[0020] In some embodiments, the mass ratio of cement slurry and nano-silica is 100:2, 100:3, 100:4, 100:5, and the mass ratio of cement, water glass and water is 3:1:2.5, 4:1:2.5, 5:1:2.5.

[0021] Preferably, the first slurry consists of cement and water, and the mass ratio of water to cement is 0.8-1.

[0022] In some embodiments, the mass ratio of water to cement is 0.8, 0.9, or 1.

[0023] Preferably, in step 2, the grouting pressure of the first slurry is 0.5 to 1 MPa, and the grouting volume of the first slurry is 1.2 to 1.5 times the volume of the borehole.

[0024] In some embodiments, the grouting pressure of the first slurry is 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa, or 1 MPa, and the grouting volume of the first slurry is 1.2 times, 1.3 times, 1.4 times, or 1.5 times the volume of the borehole.

[0025] Preferably, in step 3, the grouting pressure of the second slurry is 1.5 to 3 MPa, and the grouting volume of the second slurry is 0.5 to 0.8 times the volume of the borehole.

[0026] In some embodiments, the grouting pressure of the second slurry is 1.5 MPa, 1.8 MPa, 2.1 MPa, 2.4 MPa, 2.7 MPa, or 3 MPa, and the grouting volume of the second slurry is 0.5 times, 0.6 times, 0.7 times, or 0.8 times the volume of the borehole.

[0027] Preferably, the method further comprises step 4: covering the slope surface with fiber concrete.

[0028] Preferably, in step 4, the fiber concrete is steel fiber concrete or basalt fiber concrete, and the fiber content of the fiber concrete is 30-50 kg / m 3 The thickness of fiber concrete is 50 to 100 mm.

[0029] In some cases, the fiber content of fiber reinforced concrete is 30 kg / m 3 、35kg / m 3 , 40kg / m 3 , 45kg / m 3 , 50kg / m 3 The thickness of fiber concrete is 50mm, 60mm, 70mm, 80mm, 90mm and 100mm.

[0030] Compared with the existing technology, this solution has the following beneficial effects:

[0031] The anchoring device in this case arranges second through holes at intervals on the anchor rod and provides barbs near the second through holes. After the slurry flows out of the second through holes, the slurry can diffuse to the nearby rock and soil and the barbs, so that the primary grouting body can be connected with the barbs and the rock and soil, thereby improving the connection strength between the anchor rod and the rock and soil, thereby ensuring the anchoring performance of the anchor rod and slurry to the broken strata.

[0032] Furthermore, setting up a pressure regulating module can monitor and control the grouting pressure in real time, preventing excessive pressure from causing formation splitting or insufficient pressure from causing insufficient grouting, thereby ensuring construction quality.

[0033] This project employed a two-step grouting process: an initial low-pressure grouting to fill large cracks, followed by a secondary high-pressure grouting to form a high-strength consolidation mass. This ensured the grouting fully filled the cracks, creating a uniform, continuous grouting mass and significantly improving the grouting effect. By controlling the grouting pressure and grouting properties, grout loss and material waste were effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 Schematic diagram of the structure of the anchoring device of Example 1;

[0035] Figure 2 This is a flow chart of the anchoring construction method of Example 2;

[0036] Figure 3 This is an SEM image of the hydration product of the second slurry in Example 2;

[0037] Figure 4 This is the XRD pattern of the hydration product of the second slurry in Example 2. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0039] Example 1

[0040] refer to Figure 1-4 ,refer to Figure 1-4 , a broken stratum slope anchoring device, comprising an anchor rod 1 and a bearing plate 2, the bearing plate 2 being connected to the end of the anchor rod 1 close to the ground, and the bearing plate 2 being used to fix the anchor rod 1 in the drilled hole; the anchor rod 1 is provided with a first through hole 11 for injecting slurry, and the first through hole 11 extends along the axial direction of the anchor rod 1; the outer peripheral surface of the anchor rod 1 is provided with a plurality of second through holes 12 arranged at intervals along the axial direction of the anchor rod 1, the second through holes 12 extend in a direction perpendicular to the axis of the anchor rod 1, and the second through holes 12 are connected to the first through holes 11; the outer peripheral surface of the anchor rod 1 is provided with barbs 13, and the barbs 13 are located on the side of the second through holes 12 close to the bottom surface.

[0041] In this embodiment, the anchoring device is mainly used on the broken bottom slope.

[0042] The specific usage process of the anchoring device is as follows: first use a drilling machine to drill a hole at a suitable position in the broken stratum. After the drilling is completed, the anchor rod 1 is placed in the hole so that the end of the anchor rod 1 is exposed 50 cm above the ground and is preliminarily fixed. Then, the feed pipe mouth of the grouting machine is connected to the first through hole 11, and the grouting machine transports the slurry into the first through hole 11. The slurry in the first through hole 11 then diffuses from the second through hole 12 to the surrounding rock and soil, thereby filling the cracks in the broken bottom layer. At the same time, the slurry will also wrap around the barb 13, so that the anchor rod 1, barb 13, slurry, and rock and soil form a whole. The purpose of setting the barb 13 is to improve the connection strength between the anchor rod 1, slurry and rock and soil.

[0043] Furthermore, the projection of the barb 13 on a surface perpendicular to the axis of the second through hole 12 is a triangle.

[0044] Preferably, it also includes a pressure regulating unit 3, which includes a pressure sensor 31, a control valve 32 and a controller; the control valve 32 is connected to the end of the anchor rod 1 close to the ground, and the control valve 32 is used to control the grouting pressure when the external grouting port is grouting into the first through hole 11; the pressure sensor 31 is used to detect the grouting pressure when the external grouting port is grouting into the first through hole 11; the controller is communicated with the pressure sensor 31 and the control valve 32 respectively.

[0045] In this embodiment, the control valve 32 is a pressure control valve 32, more specifically an electromagnetic pressure control valve 32, for adjusting the grouting pressure of the slurry. The pressure sensor 31 is a pipeline pressure sensor 31. The controller is a PLC controller.

[0046] The feed pipe port of the grouting machine is connected to the anchor rod 1 via a control valve 32 , and the pressure sensor 31 is connected to one end of the control valve 32 close to the anchor rod 1 .

[0047] The controller (not shown in the figure) pre-sets the grouting pressure. When the grouting machine transports the slurry to the anchor rod 1, the pressure sensor 31 monitors the grouting pressure of the slurry in real time. When the pressure sensor 31 detects that the grouting pressure is insufficient or the grouting pressure is too high, the pressure sensor 31 sends a signal to the controller, and the controller then controls the control valve 32 to adjust the grouting pressure, thereby ensuring that the grouting pressure is within the set range and ensuring the grouting effect.

[0048] Preferably, the diameter of the anchor rod 1 is in the range of 25 to 40 mm; the diameter of the second through hole 12 is in the range of 6 to 8 mm; the distance between the plurality of second through holes 12 is in the range of 1 to 1.5 m; and the length of the barb 13 is in the range of 20 to 30 mm.

[0049] In this embodiment, the diameter range of the anchor rod 1 is 30 mm, the diameter range of the second through hole 12 is 7 mm, the distance between the second through holes 12 is 1.5 m, and the length of the barb 13 is 25 mm. Other values ​​can also be set according to actual needs.

[0050] The nano-silicon dioxide used in Examples 2-6 and Comparative Examples 1-2 was manufactured by Xianfeng Nano, with a model number of XFI05-1.

[0051] Example 2

[0052] refer to Figure 1-2 A method for anchoring a broken stratum slope is provided, based on the above-mentioned broken stratum slope anchoring device, comprising the following steps:

[0053] Before proceeding to step 1, a casing follow-up drilling rig is used to drill the broken formation. During the drilling process, wall protection mud is injected through the drill pipe to ensure the stability of the borehole wall and prevent hole collapse.

[0054] Among them, the borehole diameter is 130mm, the borehole depth is 10m, the wall protection mud is a mixture of bentonite and water, the viscosity of the wall protection mud is 28s, and the viscosity is measured by a Marsh viscometer. The borehole axis deviation is controlled within ±2° to ensure the accuracy of anchor rod installation; after drilling is completed, the residue in the hole is cleaned to ensure that the grouting channel is unobstructed.

[0055] Step 1: Use a hollow threaded steel pipe as an anchor rod, slowly insert the anchor rod into the drill hole, ensure that the anchor rod is aligned with the drill hole axis, and perform preliminary fixation. Leave 50cm at the exposed end of the anchor rod for installing the bearing plate;

[0056] Step 2: Use a grouting machine to inject the first slurry into the first through hole of the anchor rod. The first slurry flows out from the second through hole and spreads to the surrounding rock and soil, filling the large cracks in the broken stratum to form a primary grouting body.

[0057] The first slurry is composed of cement and water, the mass ratio of water to cement is 1, the viscosity of the first slurry is 12s, the grouting pressure of the first slurry is 0.5MPa, and the grouting volume of the first slurry is 1.5 times the volume of the borehole.

[0058] Step 3: After the first slurry has initially set, a grouting machine is used to inject the second slurry into the first through hole. The second slurry splits the primary grouting body from the second through hole and diffuses into the surrounding rock and soil. The second slurry fills the micro-cracks in the broken stratum and the gaps when the primary grouting body is broken, forming a secondary grouting body. The secondary grouting body and the primary grouting body form a "tree root-like" grouting body, thereby filling all the cracks in the broken stratum;

[0059] Among them, the second slurry is composed of cement slurry and nano-silica, the mass ratio of cement slurry and nano-silica is 100:3, the cement slurry is composed of cement, water glass and water, the mass ratio of cement, water glass and water is 4:1:2.5, the viscosity of the second slurry is 9s, the grouting pressure of the second slurry is 1.5MPa, and the grouting volume of the second slurry is 0.8 times the volume of the borehole.

[0060] Step 4: After the grouting is completed, let it stand for 24 hours to allow the first slurry and the second slurry to completely solidify. After complete solidification, install the bearing plate on the exposed end of the anchor rod. The bearing plate size is 200mm×200mm and the thickness is 12mm. Insert the nut on the exposed end of the anchor rod and tighten the nut with a torque wrench to ensure that the anchor rod is tightly connected to the bearing plate. The torque of the torque wrench is controlled at 120N·m. After the secondary fixing of the anchor rod is completed, use a concrete sprayer to spray the fiber with a fiber content of 40kg / m 3 The basalt fiber concrete covers the slope surface. The thickness of the fiber concrete covering the slope surface is 70mm, and the injection pressure is 0.4MPa to ensure that the concrete is tightly bonded to the slope surface.

[0061] Example 3

[0062] This embodiment is substantially the same as embodiment 2, except that: Step 2: a first slurry is injected into the first through hole of the anchor rod using a grouting machine; the first slurry flows out of the second through hole and diffuses into the surrounding rock and soil, filling large cracks in the broken stratum to form a primary grouting body;

[0063] The first slurry is composed of cement and water, the mass ratio of water to cement is 0.8, the viscosity of the first slurry is 15s, the grouting pressure of the first slurry is 1 MPa, and the grouting volume of the first slurry is 1.2 times the volume of the borehole.

[0064] Step 3: After the first slurry has initially set, a grouting machine is used to inject the second slurry into the first through hole. The second slurry splits the primary grouting body from the second through hole and diffuses into the surrounding rock and soil. The second slurry fills the micro-cracks in the broken stratum and the gaps when the primary grouting body is broken, forming a secondary grouting body. The secondary grouting body and the primary grouting body form a "tree root-like" grouting body, thereby filling all the cracks in the broken stratum;

[0065] Among them, the second slurry is composed of cement slurry and nano-silica, the mass ratio of cement slurry and nano-silica is 100:3, the cement slurry is composed of cement, water glass and water, the mass ratio of cement, water glass and water is 4:1:2.5, the viscosity of the second slurry is 9s, the grouting pressure of the second slurry is 3MPa, and the grouting volume of the second slurry is 0.5 times the volume of the borehole.

[0066] Example 4

[0067] This embodiment is substantially the same as embodiment 2, except that: Step 2: a first slurry is injected into the first through hole of the anchor rod using a grouting machine; the first slurry flows out of the second through hole and diffuses into the surrounding rock and soil, filling large cracks in the broken stratum to form a primary grouting body;

[0068] The first slurry is composed of cement and water, the mass ratio of water to cement is 0.9, the viscosity of the first slurry is 13s, the grouting pressure of the first slurry is 0.7 MPa, and the grouting volume of the first slurry is 1.3 times the volume of the borehole.

[0069] Step 3: After the first slurry has initially set, a grouting machine is used to inject the second slurry into the first through hole. The second slurry splits the primary grouting body from the second through hole and diffuses into the surrounding rock and soil. The second slurry fills the micro-cracks in the broken stratum and the gaps when the primary grouting body is broken, forming a secondary grouting body. The secondary grouting body and the primary grouting body form a "tree root-like" grouting body, thereby filling all the cracks in the broken stratum;

[0070] Among them, the second slurry is composed of cement slurry and nano-silica, the mass ratio of cement slurry and nano-silica is 100:3, the cement slurry is composed of cement, water glass and water, the mass ratio of cement, water glass and water is 4:1:2.5, the viscosity of the second slurry is 9s, the grouting pressure of the second slurry is 2.1MPa, and the grouting volume of the second slurry is 0.6 times the volume of the borehole.

[0071] Example 5

[0072] This embodiment is basically the same as Example 2, except that: the second slurry is composed of cement slurry and nano-silica, and the mass ratio of cement slurry to nano-silica is 100:2; the cement slurry is composed of cement, water glass and water, and the mass ratio of cement, water glass and water is 4:1:2.5.

[0073] Example 6

[0074] This embodiment is basically the same as Example 2, except that: the second slurry is composed of cement slurry and nano-silica, and the mass ratio of cement slurry to nano-silica is 100:5; the cement slurry is composed of cement, water glass and water, and the mass ratio of cement, water glass and water is 4:1:2.5.

[0075] Comparative Example 1

[0076] This comparative example is basically the same as Example 2, except that: Step 2: a first slurry is injected into the first through hole of the anchor rod using a grouting machine, the first slurry flows out from the second through hole, diffuses into the surrounding rock and soil, fills the large cracks in the broken stratum, and forms a primary grouting body;

[0077] The first slurry is composed of cement and water, the mass ratio of water to cement is 1, the viscosity of the first slurry is 12s, the grouting pressure of the first slurry is 0.5MPa, and the grouting volume of the first slurry is 1.5 times the volume of the borehole.

[0078] Step 3: After the first slurry is initially set, the first slurry is injected into the first through hole using a grouting machine. The first slurry splits the primary grouting body from the second through hole and spreads to the surrounding rock and soil to form a secondary grouting body.

[0079] Among them, the first slurry is composed of cement and water, the mass ratio of water to cement is 1, the viscosity of the first slurry is 12s, the second grouting pressure is 1.5MPa, and the second grouting volume is 0.8 times the borehole volume.

[0080] Comparative Example 2

[0081] This comparative example is basically the same as Example 2, except that: Step 2: a second slurry is injected into the first through hole of the anchor rod using a grouting machine, and the second slurry flows out of the second through hole and diffuses into the surrounding rock and soil to form a primary grouting body;

[0082] Among them, the second slurry is composed of cement slurry and nano-silica, the mass ratio of cement slurry and nano-silica is 100:3, the cement slurry is composed of cement, water glass and water, the mass ratio of cement, water glass and water is 4:1:2.5, the viscosity of the second slurry is 9s, the first grouting pressure is 0.5MPa, and the first grouting volume is 1.5 times the borehole volume.

[0083] Step 3: After the first slurry is initially set, a second slurry is injected into the first through hole using a grouting machine. The second slurry splits the primary grouting body from the second through hole and spreads to the surrounding rock and soil to form a secondary grouting body.

[0084] Among them, the second slurry is composed of cement slurry and nano-silica, the mass ratio of cement slurry and nano-silica is 100:3, the cement slurry is composed of cement, water glass and water, the mass ratio of cement, water glass and water is 4:1:2.5, the viscosity of the second slurry is 9s, the grouting pressure of the second slurry is 1.5MPa, and the grouting volume of the second slurry is 0.8 times the volume of the borehole.

[0085] The methods of Examples 2-6 and Comparative Examples 1-2 were used to anchor a slope in a fractured stratum. The testing method involved using a geological radar to detect cracks and cavities in the soil layer by transmitting and receiving radar waves. A rotational rheometer combined with the Herschel-Bulkley model was used to test the rheological properties of slurries with different ratios.

[0086] The results are shown in Table 1-4:

[0087] Table 1 Cracks in soil layers

[0088]

[0089]

[0090] Table 2 Mass ratio of cement slurry and nano-silica in the second slurry

[0091] Ratio number cement slurry Nanosilica A1 (control group) 100 0 A2 (Example 5) 100 2 A3 (Example 2) 100 3 A4 (Example 6) 100 5

[0092] Table 3 Shear stress of the second slurry with different ratios at various shear rates

[0093] <![CDATA[Shear rate (s -1 )]]> A1 A2 A3 A4 1 11.60 9.90 8.90 12.50 5 14.29 12.06 10.65 15.77 10 16.38 13.66 11.91 18.36 20 19.39 15.91 13.65 22.15 50 25.50 20.34 16.97 29.98 80 29.99 23.51 19.31 35.82 100 32.55 25.29 20.60 39.16

[0094] Table 4 Herschel-Bulkley rheological parameters of slurries with different ratios

[0095]

[0096]

[0097] Result analysis:

[0098] It can be seen from Examples 2-6 that the grouting method can be used to fill all cracks in the broken strata.

[0099] Compared with Comparative Example 1, Example 2 uses the method of Comparative Example 1 for construction, which will result in some microcracks, which will affect the anchoring performance of the grouting body. The reason for the presence of some microcracks may be that the first slurry is used for grouting in both grouting operations, and the first slurry has poor fluidity (high viscosity) and can flow into large cracks but not into microcracks. Moreover, the second grouting pressure is higher, which has no effect on the first slurry entering the microcracks.

[0100] Compared with Example 2, Example 2 can also fill all the cracks in the broken stratum using Example 2. However, both groutings in Example 2 use the second slurry, and the cost of the second slurry is higher. Moreover, the total grouting volume of the two groutings is large, which will greatly increase the cost of the enterprise.

[0101] In Example 2, the first grouting uses the first slurry, and the second grouting uses the second slurry. The first grouting is mainly to fill large cracks, and the required grouting amount is large, while the cost of the first slurry is low, and it meets the demand for filling large cracks. In the second grouting, the second slurry is used, and the second slurry is combined with a higher grouting pressure to fill micro cracks. At this time, the required grouting amount is smaller, which can greatly reduce the use of the second slurry and reduce corporate costs. From an economic point of view, the effect of Example 2 is better than that of Comparative Example 2.

[0102] As can be seen from Examples 2, 5, and 6, combined with Tables 2, 3, and 4, the shear thinning index of all ratios is less than 1, indicating that the second slurry has typical shear thinning properties and can significantly reduce viscosity under shear, which is beneficial for actual pumping and grouting operations. Among them, the yield stress and viscosity coefficient of the A3 (the second slurry of Example 2) ratio are the lowest, the shear thinning index is also the smallest, the fluidity is the best, and it has excellent construction adaptability and filling effect. The A2 (the second slurry of Example 5) ratio has significantly improved fluidity compared to A1 (no added nanosilica) while maintaining a certain stability, showing good shear thinning behavior and anti-settling ability. In contrast, the A1 slurry has a higher initial viscosity and average fluidity, which is suitable for conventional construction conditions; while the A4 (the second slurry of Example 6) ratio has the highest yield stress and viscosity coefficient. Although it has a certain thinning ability, it is under high pressure during pumping, which is suitable for scenarios with high requirements for anti-settling performance and a high tolerance for fluidity. Overall, the A3 (the second slurry of Example 2) ratio performs best in all rheological indicators.

[0103] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the claims and their equivalents.

Claims

1. A broken stratum slope anchoring device, characterized in that: It includes an anchor rod and a bearing plate, the bearing plate is connected to the end of the anchor rod close to the ground, and the bearing plate is used to fix the anchor rod in the drilled hole; the anchor rod is provided with a first through hole for injecting slurry, and the first through hole extends along the axial direction of the anchor rod; the outer peripheral surface of the anchor rod is provided with a plurality of second through holes arranged at intervals along the axial direction of the anchor rod, the second through holes extend in a direction perpendicular to the axis of the anchor rod, and the second through holes are connected to the first through holes; the outer peripheral surface of the anchor rod is provided with barbs, and the barbs are located on the side of the second through hole close to the bottom surface of the ground.

2. The broken stratum slope anchoring device according to claim 1, characterized in that: It also includes a pressure regulating unit, which includes a pressure sensor, a control valve and a controller; the control valve is connected to the end of the anchor rod close to the ground, and the control valve is used to control the grouting pressure when the external grouting port is grouting into the first through hole; the pressure sensor is used to detect the grouting pressure when the external grouting port is grouting into the first through hole; the controller is communicated with the pressure sensor and the control valve respectively.

3. The broken stratum slope anchoring device according to claim 1, characterized in that: The diameter of the anchor rod ranges from 25 to 40 mm; the diameter of the second through hole ranges from 6 to 8 mm; the distance between the plurality of second through holes ranges from 1 to 1.5 m; and the length of the barb ranges from 20 to 30 mm.

4. A method for anchoring a broken stratum slope, characterized in that: The broken stratum slope anchoring device according to any one of claims 1 to 3 comprises the following steps: Step 1: Place the anchor rod in the drilled hole and fix it; Step 2: injecting a first slurry into the first through hole, the first slurry flows out from the second through hole and diffuses into the surrounding rock and soil to form a primary grouting body, and the viscosity of the first slurry is 12-15s; Step 3: After the first slurry is initially set, the second slurry is injected into the first through hole. The second slurry splits the primary grouting body from the second through hole and diffuses into the surrounding rock and soil to form a secondary grouting body. The viscosity of the second slurry is 8-10s; The grouting pressure of the first slurry is lower than the grouting pressure of the second slurry.

5. The method for anchoring a broken stratum slope according to claim 4, characterized in that: The second slurry consists of cement slurry and nano-silicon dioxide, and the mass ratio of cement slurry to nano-silicon dioxide is 100:2-5; the cement slurry consists of cement, water glass and water, and the mass ratio of cement, water glass and water is 3-5:1:2.

5.

6. The method for anchoring a broken stratum slope according to claim 4, characterized in that: The first slurry consists of cement and water, and the mass ratio of water to cement is 0.8-1.

7. The method for anchoring a broken stratum slope according to claim 4, characterized in that: In step 2, the grouting pressure of the first slurry is 0.5 to 1 MPa, and the grouting volume of the first slurry is 1.2 to 1.5 times the volume of the borehole.

8. The method for anchoring a broken stratum slope according to claim 4, characterized in that: In step 3, the grouting pressure of the second slurry is 1.5 to 3 MPa, and the grouting volume of the second slurry is 0.5 to 0.8 times the volume of the drill hole.

9. The method for anchoring a broken stratum slope according to claim 4, characterized in that: Also included is step 4: covering the slope surface with fiber concrete.

10. The method for anchoring a broken stratum slope according to claim 9, characterized in that: In step 4, the fiber concrete is steel fiber concrete or basalt fiber concrete, and the fiber content of the fiber concrete is 30-50 kg / m 3 The thickness of fiber concrete is 50 to 100 mm.

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