A method for determining grouting parameters

Abstract

The application provides a grouting parameter determination method, and relates to the technical field of underground engineering grouting reinforcement. The grouting parameter determination method comprises the following steps: drawing a foundation circle on a construction stratum, constructing a grouting hole with the center of the foundation circle, and constructing two observation holes with the endpoints of any radius of the foundation circle as the center; preparing a slurry, filling the observation holes with water, and injecting the slurry into the grouting hole; gradually increasing the grouting pressure during the grouting process, and recording the grouting pressure P when water overflows from any observation hole; keeping the grouting pressure as P, continuing to inject the remaining slurry, and recording the water overflowed from the observation hole; and determining the grouting diffusion radius. Through the parameter determination method, the in-situ test of the stratum needing reinforcement can be performed, the grouting diffusion radius and the corresponding grouting pressure can be directly determined, the grouting diffusion effect can be accurately reflected, the accurate design of the grouting reinforcement engineering can be guided, the grouting can be accurately controlled, the expected reinforcement effect can be ensured, and the risk safety control can be realized.

Description

Technical Field

[0001] This invention relates to the field of underground engineering grouting reinforcement technology, and more specifically, to a method for determining grouting parameters. Background Technology

[0002] As underground engineering construction technology becomes more and more mature, when tunnel boring machines pass through unfavorable strata or major risk sources, stratum reinforcement measures have emerged, and various reinforcement technologies have also emerged one after another. Various strata also have their corresponding grouting reinforcement methods. The grouting reinforcement effect is the core of our ultimate concern, and the core influencing factor for achieving the grouting reinforcement effect is the grout diffusion radius.

[0003] When designing grouting, the grouting diffusion radius is often given as a range value, mostly based on experience, and partly based on laboratory simulation test values. However, the actual grouting environment differs greatly from experience judgments and laboratory environments, resulting in a large difference between the experience value or simulation test value and the actual value. This often leads to grouting waste or the actual grouting effect not meeting expectations during grouting reinforcement. Furthermore, in laboratory grouting, the soil layer has already been disturbed, making it difficult to simulate the actual grouting conditions of the strata. Summary of the Invention

[0004] The present invention aims to solve the problem that there is a large difference between the empirical value or simulated test value and the actual value of the grouting diffusion radius.

[0005] To address the above problems, this invention provides a method for determining grouting parameters, comprising the following steps: Step 1: Draw a foundation circle on the construction site. Construct a grouting hole with the center of the foundation circle as the center, and construct two observation holes with the endpoint of any diameter of the foundation circle as the center. Step 2: Prepare a total amount of grout Q. First, fill the two observation holes with water, and then inject the prepared grout into the grouting hole. Gradually increase the grouting pressure during the grouting process. When water overflows from any observation hole, record the grouting pressure P at this time. Step 3: Maintain the grouting pressure at P and continue grouting the remaining grout. Record the amount of water overflowing from the two observation holes after grouting. Step 4: Determine the grouting diffusion radius based on the recorded data.

[0006] The grouting parameter determination method provided by this invention has, but is not limited to, the following beneficial effects compared to existing technologies: Underground engineering projects are typically conducted 30-40 meters underground, where water fills the fissures in the strata. During grouting, the grout forces the water out of these fissures. Observation holes are placed near the grouting holes and filled with water. When water overflows from an observation hole, it indicates that the grout, by forcing the water out of the fissures, can compress it into the observation hole, causing it to overflow. This is analogous to the principle of communicating vessels, meaning that under the grouting pressure, the grout can diffuse through the strata fissures from the grouting hole to the observation hole. Based on this principle, observation holes are placed at equal intervals on both sides of the grouting hole. During grouting, if water overflows from any observation hole, it means that under the grouting pressure, the grout can just diffuse into the observation hole where water overflows. At this grouting pressure, the diffusion radius of the grout in the direction of the observation hole where water overflows is the distance from the center of the grouting hole to the center of the observation hole. If water also overflows from the other observation hole at the same time, it means that the diffusion radius of the grout in the direction of the other observation hole is also the distance from the center of the grouting hole to the center of the observation hole. At this point, it can be determined that under the grouting pressure, the grout diffusion radius is the distance from the center of the grouting hole to the center of the observation hole. If no water overflows from the other observation hole at this time, it means that the diffusion radius of the grout in the direction of the observation hole where no water overflows is less than the distance from the center of the grouting hole to the center of the observation hole. At this time, continue to inject the remaining grout, collect the amount of water overflowing from both observation holes, and determine the ratio of the diffusion radius in the direction of the observation hole where no water overflowed before to the diffusion radius in the direction of the observation hole where water overflowed before by the ratio of the amount of water overflowing from the observation holes on both sides. Then, calculate the diffusion radius in the direction of the observation hole where no water overflowed before. Take the average value of the diffusion radii in the two observation hole directions as the diffusion radius of the grout under the grouting pressure. By using this parameter determination method, in-situ tests on the strata that need to be reinforced, the grout diffusion radius and the corresponding grouting pressure can be determined intuitively, which can accurately reflect the grout diffusion effect. This helps to guide the precise design and accurate control of grouting in grouting reinforcement projects, ensure that the reinforcement achieves the expected effect, and realize risk and safety management.

[0007] Furthermore, the grouting hole and the two observation holes have the same diameter and are set as follows: , mm, the radius of the basic circle is set to , mm.

[0008] Furthermore, let there be two observation holes, X and Y. When water overflows from either observation hole, record the grouting pressure P at that moment. Then, continue injecting the remaining grout under the grouting pressure P. Let the total amount of grout injected at this time be Q, and let the amount of water overflowing from observation hole X be q. X Let q be the amount of water overflowing from hole Y. Y .

[0009] Furthermore, if the grouting diffusion radius is set to R, then, In qX >q Y hour, ; In q X ≤q Y hour, .

[0010] Furthermore, the method for determining grouting parameters also includes determining the grouting allowance coefficient based on recorded data. The grouting allowance coefficient is the proportion of the total water overflowing from all observation holes after they are sequentially arranged along the circumference of the foundation circle to the total injected grout volume Q. Let the grouting allowance coefficient be K, then... .

[0011] Furthermore, the initial grouting pressure is 0, and the grouting pressure is gradually increased at a rate of 0.1 MPa.

[0012] Furthermore, the water-cement ratio of the grout used for grouting is 1:1.

[0013] The present invention also provides a test structure for the above-mentioned method for determining grouting parameters, comprising: Grouting holes; The observation holes are two in number and symmetrically arranged on both sides of the grouting hole. The two observation holes and the grouting hole have the same diameter. The grouting hole is provided with a grouting pipe, and the outer end of the grouting pipe is connected to the grouting equipment; The observation hole was filled with water.

[0014] Furthermore, a sleeve valve tube is coaxially arranged inside the grouting hole, a grout stopper is arranged inside the sleeve valve tube, and a sleeve material is filled between the portion of the outer wall of the sleeve valve tube above the grout stopper and the inner wall of the grouting hole.

[0015] Furthermore, a PVC pipe is coaxially inserted into the opening of the observation hole, and the outer wall of the PVC pipe and the opening of the observation hole are sealed and fixed with concrete. An overflow pipe is connected to the upper end of the PVC pipe, and a measuring cylinder is connected to the end of the overflow pipe away from the PVC pipe. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the test structure used for determining grouting parameters.

[0017] Explanation of reference numerals in the attached figures: 1. Grouting hole; 11. Grouting pipe; 12. Grouting equipment; 13. Sleeve valve pipe; 14. Grout stop plug; 15. Shell material; 2. Observation hole; 21. Observation hole X; 22. Observation hole Y; 23. PVC pipe; 24. Overflow pipe; 25. Measuring cylinder. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, specific embodiments of this application are described clearly and completely below with reference to the accompanying drawings. It should be understood that the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments described in this application without creative effort will fall within the scope of protection of this application.

[0019] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application; the terms "comprising," "including," "having," "containing," "comprise," etc., in the specification, claims, and accompanying drawings of this application are open-ended terms. They indicate that a method comprises one or more steps, or an apparatus comprises one or more elements, but do not exclude the inclusion of other steps or elements. The terms "first," "second," etc., in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0022] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0023] See Figure 1 A method for determining grouting parameters according to an embodiment of the present invention includes the following steps: Step 1: Draw a foundation circle on the construction site. Construct a grouting hole 1 with the center of the foundation circle as the center, and construct two observation holes 2 with the endpoint of any diameter of the foundation circle as the center. Step 2: Prepare a total amount of grout Q. First, fill the two observation holes 2 with water, and then inject the prepared grout into the grouting hole 1. Gradually increase the grouting pressure during the grouting process. When water overflows from any observation hole 2, record the grouting pressure P at this time. Step 3: Maintain the grouting pressure at P and continue grouting the remaining grout. Record the amount of water overflowing from the two observation holes 2 after grouting. Step 4: Determine the grouting diffusion radius based on the recorded data.

[0024] In this embodiment, the underground project is typically located 30 to 40 meters underground, with water filling the fissures in the strata. During grouting, the grout forces the water into these fissures. By setting up observation holes 2 near the grouting hole 1 and filling them with water, the overflow of water from the observation holes 2 indicates that the grout, by forcing the water into the fissures, can push the water into the observation holes 2, causing the water to overflow. This is analogous to the principle of communicating vessels, demonstrating that under this grouting pressure, the grout can diffuse from the grouting hole 1 to the observation hole 2 through the strata fissures. Based on the above principle, observation holes 2 are equidistantly arranged on both sides of the grouting hole 1. During the grouting process, if water overflows from any observation hole 2, it indicates that the grout can just diffuse into the observation hole 2 where water overflows under the grouting pressure. Under this grouting pressure, the diffusion radius of the grout in the direction of the observation hole 2 where water overflows is the distance from the center of the grouting hole 1 to the center of the observation hole 2. If water also overflows from the other observation hole 2 at this time, it indicates that the diffusion radius of the grout in the direction of the other observation hole 2 is also the distance from the center of the grouting hole 1 to the center of the observation hole 2. It can be determined that under this grouting pressure, the grout diffusion radius is the distance from the center of grouting hole 1 to the center of observation hole 2. If no water overflows from the other observation hole 2 at this time, it means that the diffusion radius of the grout in the direction of the observation hole 2 where no water overflows is less than the distance from the center of grouting hole 1 to the center of observation hole 2. At this time, continue to inject the remaining grout, collect the amount of water overflowing from both observation holes 2, and determine the ratio of the diffusion radius in the direction of the observation hole 2 where no water overflowed before to the diffusion radius in the direction of the observation hole 2 where water overflowed before by the ratio of the amount of water overflowing from the observation holes 2 on both sides. Then, calculate the diffusion radius in the direction of the observation hole 2 where no water overflowed before. Take the average value of the diffusion radii in the two observation holes 2 directions as the diffusion radius of the grout under this grouting pressure. By using this parameter determination method and conducting on-site tests in the strata that need to be reinforced, the grout diffusion radius can be accurately determined, which directly reflects the grout diffusion effect, that is, the size of the water overflow from observation hole 2. At the same time, the grouting pressure can be determined, which helps to guide the precise design and precise control of grouting in grouting reinforcement projects, ensure that the reinforcement achieves the expected effect, and realize risk and safety management.

[0025] The amount of grout Q to be prepared is determined based on the geological environment to be reinforced. When the geological formation is loose, the diffusion coefficient is large, and a small amount of grout will result in overflow. When the geological formation is dense, the diffusion coefficient is small, and even a large amount of grout may not overflow. The grout is generally prepared using a cement grout mixing tank, with each tank containing 1 m³. For example, if we determine that 0.6 m³ is needed under the current geological conditions, we prepare one tank. When about 0.6 m³ of grout is injected, water will start to overflow. The remaining grout can be injected at the same injection pressure as when water overflows. By continuing to inject grout, the overflow amount in observation holes 2 on both sides is collected, and the average diffusion radius is calculated. Of course, if after one tank of grout is injected, there is still no water overflowing from observation hole 2 or only water overflowing, we can prepare another tank or half a tank of grout to continue the experiment.

[0026] In addition, if water overflows from one observation hole 2 but not from the other, and if no water overflows from the other observation hole 2 after injecting the remaining grout, we can continue to prepare a certain amount of grout and continue to inject it. The amount prepared depends on the formation environment, such as half a bucket. If no water overflows at this time, it is determined that under the grouting pressure P, the grout does not diffuse in the direction of the observation hole 2 where no water overflows, that is, the diffusion radius is zero.

[0027] Of course, the basic circle is obtained by drawing a line at the construction stratum that needs grouting reinforcement. The radius of the basic circle is the distance from the center of grouting hole 1 to the center of observation hole 2. Alternatively, a straight line can be drawn, with the midpoint of the line as the center of the circle for grouting hole 1, and the two endpoints of the line as the centers of the two observation holes 2.

[0028] Furthermore, the diameter of the grouting hole 1 and the two observation holes 2 are the same and set as b, b = 50~100mm, and the radius of the foundation circle is set as a, a = 1000~3000mm.

[0029] In this embodiment, the size of grouting hole 1 and observation hole 2 are constructed according to the size of grouting hole 1 during normal grouting reinforcement. The radius of the foundation circle, that is, the distance from the center of grouting hole 1 to the center of observation hole 2, is estimated based on the approximate arrangement distance of reinforcement piles under the current geological conditions, and is generally between 1000 and 3000 mm.

[0030] Furthermore, let the two observation holes 2 be observation hole X21 and observation hole Y22, respectively. When water overflows from either observation hole 2, record the grouting pressure P at this time. Then, continue to inject the remaining grout under the grouting pressure P. The total amount of grout injected at this time is Q, and the amount of water overflowing from observation hole X21 is denoted as q. X Let q be the amount of water overflowing from observation hole Y22. Y Let the grouting diffusion radius be R, then, In q X >q Y hour, ; In q X ≤q Y hour, .

[0031] In this embodiment, at q X >q Y At that time, water first overflowed from observation hole X21. Subsequently, after the remaining slurry was injected under pressure P, the amount of water overflowing from observation hole X21 was q. X Observe the amount of water overflowing from hole Y22, q Y The amount of water overflowing from observation hole Y22 is equal to the amount of water overflowing from observation hole X21. Therefore, it can be determined that the diffusion radius in the Y22 direction of the observation hole is the same as the diffusion radius in the X21 direction of the observation hole. And if the diffusion radius in the X21 direction of the observation hole is determined to be 'a', then the grout diffusion radius can be calculated by averaging the values. Similarly, in q X <q Y hour, Of course, in q X =q Y When the diffusion radius in the X21 and Y22 directions of the observation hole is the same, it can be determined that the diffusion radius is a, and the above formula also applies; when q X or q Y When the value is 0, it is assumed that the slurry does not diffuse in the direction of observation hole 2 where the overflow rate is 0. At this time, the diffusion radius can be determined as 0. .

[0032] In geological environments, the diffusion capacity of grout is generally consistent in all directions, with little difference. For example, along the direction from one observation hole 2 to another, the diffusion capacity of grout is basically the same, or gradually increases or decreases slightly. This is reflected in the overflow volume q collected in observation hole X21 after grouting. X And the overflow q of observation hole Y22 Y The difference won't be too big.

[0033] Furthermore, the method for determining grouting parameters also includes determining the grouting allowance coefficient based on recorded data. The grouting allowance coefficient is the proportion of the total water overflowing from observation holes 2 after they are arranged sequentially along the circumference of the foundation circle to the total injected grout volume Q. Let the grouting allowance coefficient be K, then... .

[0034] In this embodiment, the grouting allowance coefficient is also determined by the recorded data. Specifically, the grouting allowance coefficient is the ratio of the total amount of water overflowing from the observation holes 2 arranged sequentially around the circumference of the foundation circle when the total amount of injected grout is Q. This can be understood as the grouting diffusion process, where a portion of the grout fills into the stratum, and after filling, it continues to fill outwards. The portion that overflows from the observation holes 2 is the remaining portion after filling the stratum. The grout diffuses in the stratum from the grouting point outwards. Therefore, the total amount of holes on the circumference of the foundation circle is calculated, and then the ratio is used to determine the total amount of cement grout that diffuses outwards per cubic meter during subsequent stratum grouting reinforcement, guiding the estimation of grout usage during stratum grouting reinforcement.

[0035] In the formula for calculating the grouting allowance coefficient K, Indicates a radius of How many objects with a diameter of [missing information] can fit on the circumference of a circle? The question asks how many observation holes (2) can be placed on the circumference of the basic circle. This calculation is a rough estimate; a more detailed calculation would require further details. For radius The circumference of the circle, The distance between the centers of two adjacent observation holes 2; This indicates the average amount of water overflowing from each observation well 2, expressed in ml. -6 The total volume of slurry, Q, is corrected for by unit and expressed in m³.

[0036] Furthermore, the initial grouting pressure is 0, and the grouting pressure is gradually increased at a rate of 0.1 MPa.

[0037] During grouting reinforcement of the formation, the grouting pressure is generally between 0.8 and 2.0 MPa. In this embodiment, the initial grouting pressure is 0, and the grouting pressure is gradually increased at a rate of 0.1 MPa to observe whether water overflows from observation hole 2.

[0038] Furthermore, the water-cement ratio of the grout used for grouting is 1:1.

[0039] The water-cement ratio of grout commonly used for grouting reinforcement of strata is 1:1.

[0040] Taking a test before a grouting reinforcement project as an example, the specific geological environment was a soil-like strongly weathered quartz sandstone stratum. The diameter of the grouting hole 1 and the observation hole 2 was 75 mm, the hole spacing a was 1500 m, and the drilling depth was 30 m. When the grouting pressure was 1.2 MPa, water overflowed from the observation hole 2. At this time, the amount of grout injected was about 0.4 m³. Under the grouting pressure of 1.2 MPa, about 0.6 m³ of grout was injected. The total amount of grout injected was about 1 m³, i.e., one bucket. The overflow volume of the two observation holes 2 was 782 ml and 801 ml, respectively. According to the above formula, the grouting diffusion radius R = 1482 mm, which is about 1.48 m, and the grouting margin coefficient K = 0.0994.

[0041] Reference Figure 1 An experimental structure according to an embodiment of the present invention includes, Grouting hole 1; There are two observation holes 2, which are symmetrically arranged on both sides of the grouting hole 1. The diameters of the two observation holes 2 and the grouting hole 1 are the same. A grouting pipe 11 is installed inside the grouting hole 1, and the outer end of the grouting pipe 11 is connected to the grouting equipment 12. Fill observation hole 2 with water.

[0042] Furthermore, a sleeve valve tube 13 is coaxially arranged inside the grouting hole 1, and a grout stop plug 14 is arranged inside the sleeve valve tube 13. The outer wall of the sleeve valve tube 13 above the grout stop plug 14 and the inner wall of the grouting hole 1 are filled with a casing material 15.

[0043] Furthermore, a PVC pipe 23 is coaxially inserted into the opening of the observation hole 2. The outer wall of the PVC pipe 23 and the opening of the observation hole 2 are sealed and fixed with concrete. An overflow pipe 24 is connected to the upper end of the PVC pipe 23, and a measuring cylinder 25 is connected to the end of the overflow pipe 24 away from the PVC pipe 23.

[0044] In this embodiment, the specific steps for conducting the experiment using the above-described experimental structure include: Step 1: Prepare one set of grouting equipment 12, several sleeve valve pipes 13, one grouting pipe 11 (with grouting head), one grout stop plug 14, PVC pipe 23, overflow pipe 24 (soft hose), pressure gauge, measuring cylinder 25, record sheet, etc. Step 2: First, construct one grouting hole 1 and two observation holes 2. The three holes are in a straight line and the diameter of each hole is b. The observation holes 2 are located on both sides of the grouting hole 1, and the center distance between the observation holes 2 and the center of the grouting hole 1 is a. Step 3: Insert the casing material 15 into the grouting hole 1, then seal the bottom end of the sleeve valve pipe 13 and insert it into the bottom of the grouting hole 1; install the PVC pipe 23 with the top opening in the observation hole 2, with half of it protruding from the ground, and seal and fix it with concrete at the ground. After it solidifies, a water pipe can be coaxially installed inside the observation hole 2. The lower end of the water pipe is a certain distance from the bottom of the observation hole 2. This distance is within the effective grouting reinforcement thickness range or slightly greater than this range. Step 4: Fill the observation hole 2 with water until it overflows from the opening at the top of the PVC pipe 23; Step 5: Make a hole at the top of the PVC pipe 23 through the observation hole 2 and connect a flexible hose. Connect the other end of the flexible hose to the measuring cylinder 25. Step 6: Connect the grouting pipe 11 to the grouting hole 1. Connect one end of the grouting pipe 11 to the grout stop plug 14, and then insert it into the bottom of the sleeve valve pipe 13 inside the grouting hole 1. Step 7: Prepare a certain amount of cement slurry Q with a water-cement ratio of 1:1; Step 8: Grout into grouting hole 1. Start the grouting pressure from 0 and gradually increase it by 0.1 MPa each time. Have a designated person observe the water flow from observation hole 2. When water overflows from observation hole 2, record the grouting pressure P. Step 9: Then maintain the grouting pressure at P and continue grouting until all the grout is used up. Then record the amount of water collected in the two measuring cylinders. Step 10: Calculate the grouting diffusion radius and grouting allowance coefficient.

[0045] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for determining grouting parameters, characterized in that, Includes the following steps: Step 1: Draw a foundation circle on the construction site, and construct a grouting hole with the center of the foundation circle as the center (1). Construct two observation holes with the endpoint of any diameter of the foundation circle as the center (2). Step 2: Prepare a total amount of grout Q. First, fill the two observation holes (2) with water, and then inject the prepared grout into the grouting hole (1). Gradually increase the grouting pressure during the grouting process. When water overflows from any observation hole (2), record the grouting pressure P at this time. Step 3: Maintain the grouting pressure at P and continue grouting the remaining grout. Record the amount of water overflowing from the two observation holes (2) after grouting. Step 4: Determine the grouting diffusion radius based on the recorded data.

2. The method for determining grouting parameters according to claim 1, characterized in that, The grouting hole (1) and the two observation holes (2) have the same diameter and are set as b, b = 50~100mm. The radius of the foundation circle is set as a, a = 1000~3000mm.

3. The method for determining grouting parameters according to claim 2, characterized in that, Two observation holes (2) are observation hole X (21) and observation hole Y (22), when water overflows in any one observation hole (2), record the grouting pressure P at this time, then continue to inject the remaining slurry under the grouting pressure P, at this time the total amount of the injected slurry is Q, the water overflowed in observation hole X (21) is set as q X , and the water overflowed in observation hole Y (22) is set as q Y .

4. The method for determining grouting parameters according to claim 3, characterized in that, Let the grouting diffusion radius be R, then, In q X >q Y hour, ; In q X ≤q Y hour, .

5. The method for determining grouting parameters according to claim 3, characterized in that, It also includes determining the grouting allowance coefficient based on the recorded data. The grouting allowance coefficient is the ratio of the total water overflowing from all observation holes (2) after they are arranged sequentially along the circumference of the foundation circle to the total injected grout volume Q. Let the grouting allowance coefficient be K, then... 。 6. The method for determining grouting parameters according to claim 1, characterized in that, The initial grouting pressure is 0, and the grouting pressure is gradually increased at a rate of 0.1 MPa.

7. The method for determining grouting parameters according to claim 1, characterized in that, The water-cement ratio of the grout used for grouting is 1:

1.

8. A test structure for use in the grouting parameter determination method according to any one of claims 1 to 7, characterized in that, include, Grouting hole (1); Observation holes (2), there are two observation holes (2) and they are symmetrically arranged on both sides of the grouting hole (1). The two observation holes (2) and the grouting hole (1) have the same diameter; The grouting hole (1) is provided with a grouting pipe (11), and the outer end of the grouting pipe (11) is connected to the grouting equipment (12). The observation hole (2) is filled with water.

9. The test structure according to claim 8, characterized in that, A sleeve valve tube (13) is coaxially arranged inside the grouting hole (1), and a grout stop plug (14) is arranged inside the sleeve valve tube (13). The part of the outer wall of the sleeve valve tube (13) above the grout stop plug (14) and the inner wall of the grouting hole (1) are filled with shell material (15).

10. The test structure according to claim 8, characterized in that, A PVC pipe (23) is coaxially inserted at the opening of the observation hole (2). The outer wall of the PVC pipe (23) and the opening of the observation hole (2) are sealed and fixed with concrete. An overflow pipe (24) is connected to the upper end of the PVC pipe (23). A measuring cylinder (25) is connected to the end of the overflow pipe (24) away from the PVC pipe (23).

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