Quantitative calculation method for compression bearing capacity of grouting body of pressure type anti-floating anchor rod
Through indoor and in-situ experimental research and combined with theoretical analysis, a pressure bearing capacity calculation model for pressure anchor grouting bodies was established, which solved the problem of inaccurate calculation of grouting bodies in the existing technology, and achieved a more accurate bearing capacity evaluation.
Patent Information
- Application Number
- CN202510078015.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-17
- Publication Date
- 2025-06-03
AI Technical Summary
The prior art is difficult to accurately calculate the bearing capacity of the pressure-type floating anchor grouting body during the pressure process. It is affected by groundwater leakage, material and formation binding factors, resulting in inaccurate calculation results.
Through indoor simulation experiments and in-situ experiments, the influence of rib diameter, pressure bearing plate size, and design parameters of constraints on the pressure bearing capacity of the grouting body was studied. Combined with experimental data and theoretical analysis, a calculation model for the pressure bearing capacity of the pressure anchor grouting body was established, and the theoretical model was optimized to improve the accuracy of the calculation.
The accurate and scientific calculation of the pressure bearing capacity of the grouting body of the pressure-type floating anchor grouting body is achieved, the accuracy and reliability of the results are improved, and the problems of cracking damage and uncertain bearing capacity of the grouting body are solved.
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Figure CN120086474A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of anti - floating anchor rods, and particularly to a quantitative calculation method for the compressive bearing capacity of the grouting body of a pressure - type anti - floating anchor rod. Background Technique
[0002] Anchor rods are widely used in projects such as high - slope anchoring, deep - foundation - pit support, and anti - floating structures. According to the different stress states of the anchor - rod grouting body, anchor rods are generally divided into tension - type anchor rods and pressure - type anchor rods. The tendon of the pressure - type anchor rod is wrapped by a casing throughout its length to form a full - length non - bonded state. The load received by the anchor rod is directly transmitted to the bearing body at the bottom through the non - bonded tendon. After the bearing body squeezes the grouting body, the bearing capacity is provided by the side resistance at the interface between the grouting body and the rock - soil mass.
[0003] The calculation of the compressive bearing capacity of the grouting body at the bearing body of the pressure - type anchor rod is an extremely important link in the bearing - capacity design of the pressure - type anchor rod. During the construction process of the pressure - type anchor rod, the anchor rod is installed by pouring the grouting body. The grouting body and the anchor rod are fixed in the construction stratum. The grouting body of the anchor rod will be squeezed by the leakage of groundwater, resulting in the rupture and damage of the grouting body. Due to factors such as the material of the grouting body and the binding force of the stratum on the grouting body during the compression process of the anchor - rod grouting body, the compressive bearing capacity of the grouting body is different, which is not convenient for accurately and scientifically calculating the compressive bearing capacity of the anchor - rod grouting body. Summary of the Invention
[0004] The purpose of the present invention is to provide a quantitative calculation method for the compressive bearing capacity of the grouting body of a pressure - type anti - floating anchor rod to solve the problems raised in the above - mentioned background technique.
[0005] To achieve the above - mentioned purpose, the present invention provides the following technical solution: A quantitative calculation method for the compressive bearing capacity of the grouting body of a pressure - type anti - floating anchor rod, including the following specific steps:
[0006] Step S1: Indoor simulation experiment. Through indoor loading tests, study the influence and law of the tendon diameter, bearing - plate size, perforation of the bearing - plate tendon, and spiral - tendon factors on the compressive bearing capacity and failure mode of the grouting body;
[0007] Step S2: In - situ experiment. Based on the results of the indoor model experiment, select different strata to formulate an in - situ test plan to implement on - site tests and detections, and measure the compressive bearing capacity of the grouting body of the pressure - type anchor rod in - situ and compare it with the strength of the test block;
[0008] Step S3: Experimental data collection and processing. Combining the standard calculation method of the compressive bearing capacity of the grouting body and the results of the indoor experiment, further analyze the enhancement effect of the compressive bearing capacity of the grouting body of the pressure - type anchor rod;
[0009] Step S4: Establish an experimental model. Based on the indoor experiment and field test results, conduct research on the calculation model of the compressive bearing capacity of the grouted body of the pressure-type anchor rod, propose a calculation method for the compressive bearing capacity, optimize the theoretical model in combination with the test results, further conduct a quantitative study on the confinement effect of the calculation of the compressive bearing capacity of the grouted body of the pressure-type anchor rod, and finally propose a calculation method for the compressive bearing capacity of the grouted body of the pressure-type anchor rod.
[0010] Preferably, the indoor simulation experiment in step S1 includes the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod in the unconstrained state and the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod in the constrained state. The experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod in the unconstrained state conducts the compressive test of the grouted body for the grouted body with different bearing plate areas, spiral bars, opening diameters, and opening numbers by combining the design parameters of the bearing body and the tendon body of the pressure-type anti-floating anchor rod in the actual project.
[0011] Preferably, based on the research results of the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod in the unconstrained state, the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod in the constrained state further conducts an indoor experiment on the compressive mechanism of the grouted body of the pressure-type anchor rod in the constrained state. The main research parameters are the bearing plate, tendon diameter, tendon quantity, confinement size, spiral bar, and confinement strength. Study the compressive failure law, change law of compressive bearing capacity, and compressive failure mode of the grouted body with different bearing plate areas, opening diameters, opening numbers, and spiral bars under different confinement states, evaluate the influence law of confinement on the strength improvement of the grouted body, and reveal the influence mechanism and influence law of confinement on the compressive bearing capacity of the grouted body.
[0012] Preferably, the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod in the unconstrained state includes the following steps:
[0013] Step S11: Fabricate the experimental mold. Fabricate the grouted body casting mold through a round pipe.
[0014] Step S12: Cast the grouted body. Insert a round pipe at the center position of the mold, then add neat cement slurry to the inner cavity of the mold. After 7 days of curing, remove the round pipe at the center position and demold the grouted body.
[0015] Step S13: Conduct the experimental loading. Polish the top of the grouted body to be flat, and install two groups of strain gauges on both sides of the vertical surface of the grouted body. Each group has 3 strain gauges, which are in a horizontal state and are arranged vertically at intervals. The interval between two adjacent strain gauges is 40 mm.
[0016] Step S14: Conduct the experiment. Apply a pressure test to the grouted body through a universal testing machine. Place a pressure conduction column between the testing machine and the grouted body, and set displacement measuring instruments on both sides of the pressure conduction column. Use the testing machine to apply pressure to the conduction column, transfer the pressure to the grouted body until cracks appear in the grouted body, and continue to apply pressure until the grouted body is damaged.
[0017] Preferably, the experimental study on the compression mechanism of the pressure - type anchor grouted body under the constrained state includes the following steps:
[0018] Step S15: Fabricate the experimental mold. Form a casting mold for the grouted body by making a circular tube.
[0019] Step S16: Cast the grouted body. Insert a circular tube at the center of the mold, then add neat cement slurry into the inner cavity of the mold to form the grouted body. After the grouted body is formed, remove the circular tube and demold the grouted body.
[0020] Step S17: Construct the constraint body. Sleeve two semi - circular tube templates outside the grouted body to form a circular - tube - shaped cavity. Add neat cement slurry into the cavity between the template and the grouted body to form the constraint body. After curing for 7 days, remove the template to obtain the grouted body in the constrained state.
[0021] Step S18: Conduct the experimental loading. Polish the top of the grouted body to be flat, and install two groups of strain gauges on both sides of the vertical surface of the constraint body. Each group has 3 strain gauges, which are in a horizontal state and are arranged vertically at intervals. The interval between two adjacent strain gauges is 40 mm.
[0022] Step S19: Conduct the experiment. Apply a pressure test to the grouted body through a universal testing machine. Place a pressure conduction column between the testing machine and the grouted body, and set displacement measuring instruments on both sides of the pressure conduction column. Use the testing machine to apply pressure to the conduction column, transfer the pressure to the grouted body until cracks appear in the grouted body, and continue to apply pressure until the grouted body is damaged.
[0023] Preferably, the in - situ experiment includes the following steps:
[0024] Step S21: Select the formation. Develop an experimental plan according to different formations.
[0025] Step S22: Cast the grouted body. Open a grouting hole in the formation, place a circular tube at the center of the grouting, and then inject neat cement slurry into the grouting hole. After curing for 7 days, obtain the grouted body.
[0026] Step S23: Conduct the experimental loading. Open installation holes on both sides of the formation outside the grouting hole, and install two groups of load sensors and displacement gauges on both sides of the vertical surface of the grouted body. The load sensors and displacement gauges are located inside the installation holes.
[0027] Step S24: Conduct the experiment. Press the jack against the surface of the grouting body to tension the tendon, and use a load sensor and a displacement gauge to collect the tensile displacement and tensile load of the tendon respectively. Continuously apply pressure until the grouting body fails.
[0028] Preferably, the stress formula of the grouting body is as follows:
[0029]
[0030] where m 2 is the end area of the grouting body, is the internal friction angle of the grouting body, c g is the cohesion of the grouting body, σ n is the uniform compressive stress on the inner hole.
[0031] Preferably, the inner diameter of the restraint body is d, the outer diameter is d 1 , and for a cylinder with a uniform pressure on the inner hole, according to the polar coordinate solution of the axisymmetric plane stress problem in elasticity theory, it is as follows:
[0032]
[0033] ε φ is the circumferential strain, E and μ are the elastic modulus and Poisson's ratio of the restraint body respectively, and ρ is the polar radius with the geometric center of the circular ring restraint body as the pole in the polar coordinate system;
[0034] When the circumferential stress on the inner wall of the restraint body reaches the tensile strength of the restraint body, the restraint body fails, and at the same time the grouting body fails. It can be obtained that:
[0035]
[0036] σ t is the tensile strength of the grouting body, d 1 / d = n.
[0037] Preferably, the experimental model is established by using the press cone model to calculate the compressive bearing capacity of the grouting body at the bottom of the pressure - type anchor rod carrier. When the grouting body fails, the bottom grouting body can be divided into a compaction cone, a failure zone and an elastic zone.
[0038] Preferably, in the indoor simulation experiment in step S1, a cylindrical cement slurry body is used as the grouting body for vertical loading tests on the grouting body, to study the influence and law of various factors on the compressive failure mode of the pressure - type anchor rod grouting body, and to analyze the formation mechanism of different failure modes, so as to obtain the failure mechanism of the corresponding failure mode.
[0039] The technical effects and advantages of the present invention:
[0040] The present invention adopts a research method combining laboratory tests, in-situ tests, and theoretical analysis. With the compressive bearing capacity of the grouted body of the pressure-type anchor rod as the core, from the compressive failure mechanism of the grouted body of the pressure-type anchor rod, to the analysis of the compressive strengthening effect of the grouted body of the pressure-type anchor rod, and further to the physical and chemical calculation method of the compressive strengthening effect at three levels, using the test results of laboratory tests and the failure phenomena of the grouted body, combined with the results of field tests, to establish and improve the compressive failure model of the grouted body of the pressure-type anchor rod, and to propose a quantitative calculation method for the rock mass constraint effect to improve the accuracy of the results. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] Figure 1 It is a schematic diagram of the framework of the quantitative calculation method for the compressive bearing capacity of the grouted body of the pressure-type anti-floating anchor rod of the present invention.
[0042] Figure 2 It is a schematic diagram of the structure of the indoor simulation experiment of the present invention.
[0043] Figure 3 It is a schematic diagram of the test research process for the compressive mechanism of the grouted body of the pressure-type anchor rod under the unconstrained state of the present invention.
[0044] Figure 4 It is a schematic diagram of the test research process for the compressive mechanism of the grouted body of the pressure-type anchor rod under the constrained state of the present invention.
[0045] Figure 5 It is a schematic diagram of the in-situ experiment process of the present invention.
[0046] Figure 6 It is a schematic diagram of the load-displacement curve of the grouted body of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0047] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0048] The present invention provides a quantitative calculation method for the compressive bearing capacity of the grouted body of a pressure-type anti-floating anchor rod as shown in Figures 1-5 and includes the following specific steps:
[0049] Step S1: Indoor simulation experiment. Through indoor loading tests, study the influence and law of the diameter of the tendon, the size of the bearing plate, the perforation of the tendon on the bearing plate, and the spiral tendon on the compressive bearing capacity and failure mode of the grouted body;
[0050] Step S2: In-situ experiment. Based on the results of indoor model tests, different strata are selected to formulate an in-situ test plan for on-site tests and inspections. The compressive bearing capacity of the grouted body of the pressure-type anchor rod is tested in-situ and compared with the strength of the test block.
[0051] Step S3: Experimental data collection and processing. Combining the standard calculation method of the compressive bearing capacity of the grouted body and the results of indoor experiments, the enhancement effect of the compressive bearing capacity of the grouted body of the pressure-type anchor rod is further analyzed.
[0052] Step S4: Establish an experimental model. Based on the results of indoor experiments and on-site tests, research on the calculation model of the compressive bearing capacity of the grouted body of the pressure-type anchor rod is carried out, and a calculation method for the compressive bearing capacity is proposed. The theoretical model is optimized in combination with the test results, and the constraint effect of the calculation of the compressive bearing capacity of the grouted body of the pressure-type anchor rod is further quantitatively studied. Finally, a calculation method for the compressive bearing capacity of the grouted body of the pressure-type anchor rod is proposed.
[0053] The indoor simulation experiment in Step S1 includes the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod under the unconstrained state and the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod under the constrained state. The experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod under the unconstrained state is carried out by combining the design parameters of the bearing body and the reinforcement of the pressure-type anti-floating anchor rod in the actual project, and the compressive test of the grouted body is carried out for the grouted body with different bearing plate areas, spiral reinforcements, opening diameters and opening numbers.
[0054] Based on the results of the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod under the unconstrained state, the experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod under the constrained state is further carried out. The main research parameters are the bearing plate, the diameter of the reinforcement, the number of reinforcements, the size of the constraint, the spiral reinforcement and the strength of the constraint. The compressive failure law, the change law of the compressive bearing capacity and the compressive failure mode of the grouted body with different bearing plate areas, opening diameters and opening numbers, and spiral reinforcements under different constraint states are studied, the influence law of the constraint on the strength improvement of the grouted body is evaluated, and the influence mechanism and influence law of the constraint on the compressive bearing capacity of the grouted body are revealed.
[0055] The experimental study on the compressive mechanism of the grouted body of the pressure-type anchor rod under the unconstrained state includes the following steps:
[0056] Step S11: Fabrication of the experimental mold. The grout pouring mold is formed by fabricating a circular pipe.
[0057] Step S12: Grout pouring. A circular pipe is inserted through the center position of the mold, and then neat cement slurry is added to the inner cavity of the mold. After 7 days of curing, the circular pipe at the center position is removed, and the grouted body is demolded.
[0058] Step S13: Experiment loading. Grind the top of the grouting body to be flat, and install two groups of strain gauges on both sides of the vertical surface of the grouting body. Each group has 3 strain gauges, which are in a horizontal state and are arranged at vertical intervals. The interval between two adjacent strain gauges is 40 mm.
[0059] Step S14: Experiment conducting. Conduct a pressure test on the grouting body through a universal testing machine. Place a pressure conduction column between the testing machine and the grouting body, and set displacement measuring instruments on both sides of the pressure conduction column. Use the testing press to apply pressure to the conduction column, and transfer the pressure to the grouting body until cracks appear in the grouting body, and continue to apply pressure until the grouting body is damaged.
[0060] The experimental study on the compression mechanism of the pressure-type anchor grouting body under the constrained state includes the following steps:
[0061] Step S15: Experiment mold making. Make a grouting body casting mold through a circular pipe.
[0062] Step S16: Grouting body casting. Insert a circular pipe at the center position of the mold, and then add neat cement slurry to the inner cavity of the mold to form a grouting body. After the grouting body is formed, remove the circular pipe and demold the grouting body.
[0063] Step S17: Constraint body construction. Sleeve two semi-circular pipe templates outside the grouting body to form a circular tubular cavity. Add neat cement slurry to the inner cavity between the template and the grouting body to form a constraint body. After curing for 7 days, remove the template to obtain a grouting body in the constrained state.
[0064] Step S18: Experiment loading. Grind the top of the grouting body to be flat, and install two groups of strain gauges on both sides of the vertical surface of the constraint body. Each group has 3 strain gauges, which are in a horizontal state and are arranged at vertical intervals. The interval between two adjacent strain gauges is 40 mm.
[0065] Step S19: Experiment conducting. Conduct a pressure test on the grouting body through a universal testing machine. Place a pressure conduction column between the testing machine and the grouting body, and set displacement measuring instruments on both sides of the pressure conduction column. Use the testing press to apply pressure to the conduction column, and transfer the pressure to the grouting body until cracks appear in the grouting body, and continue to apply pressure until the grouting body is damaged.
[0066] The in-situ experiment includes the following steps:
[0067] Step S21: Select the formation. Develop an experimental plan according to different formations.
[0068] Step S22: Grouting body casting. Open a grouting hole in the formation, place a circular pipe at the center of the grouting, and then inject neat cement slurry into the grouting hole. After curing for 7 days, obtain a grouting body.
[0069] Step S23: Experimental loading. Installation holes are drilled on both sides of the formation outside the grouting holes, and two sets of load sensors and displacement gauges are installed on both sides of the vertical surface of the grout body. The load sensors and displacement gauges are located inside the installation holes.
[0070] Step S24: Experiment execution. The jack is pressed against the surface of the grout body to tension the tendon, and the load sensor and displacement gauge are used to collect the tensile displacement and tension load of the tendon respectively. Continuous pressure is applied until the grout body fails.
[0071] The stress formula of the grout body is as follows:
[0072]
[0073] Where m 2 is the end area of the grout body, is the internal friction angle of the grout body, c g is the cohesion of the grout body, σ n is the uniform compressive stress on the inner hole.
[0074] The inner diameter of the constraint body is d, the outer diameter is d 1 , and for a cylinder with a uniform pressure on the inner hole, according to the polar coordinate solution of the axisymmetric plane stress problem in elastic mechanics, it is as follows:
[0075]
[0076] is the circumferential strain, E and μ are the elastic modulus and Poisson's ratio of the constraint body respectively, and ρ is the polar radius with the geometric center of the circular ring constraint body as the pole of the polar coordinate system;
[0077] When the circumferential stress on the inner wall of the constraint body reaches the tensile strength of the constraint body, the constraint body fails, and at the same time the grout body fails. It can be obtained that:
[0078]
[0079] σ t is the tensile strength of the grout body, d 1 / d = n.
[0080] A compression cone model is used to calculate the compressive bearing capacity of the grout body at the bottom of the pressure-type anchor carrier when establishing the experimental model. When the grout body fails, the bottom grout body can be divided into a compaction cone, a failure zone, and an elastic zone.
[0081] When the grout body fails, an inverted conical compaction cone appears at the bottom of the cylindrical steel column. There are obvious fracture marks on the conical surface of the compaction cone. Carefully remove the grout body and peel off part of the broken body. Approximately a regular cone appears below the inverted cone. The generatrices of the regular cone and the inverted cone are approximately connected in a straight line, and the regular cone and the grout body at its bottom are relatively intact. However, the clamped part of the conical surfaces of the upper inverted cone and the lower regular cone splits into multiple blocks along the axial direction. Since the bottom of the steel column is not a smooth surface, after the grout body is compressed, under the restraint of the frictional force at the bottom of the steel column, the bottom takes the form of an inverted compaction cone, and the cone apex angle is 55.4 - 63.8°. When the load continues to increase, with the increase of the axial displacement, the conical surface of the compaction cone generates shear and extrusion forces on the surrounding grout body. When the restraint force of the restraint body on the grout body and the force on the surface of the bottom regular cone cannot balance it, the restraint body cracks and the grout body fails.
[0082] During the test process, after the load is applied to a certain value, several tiny cracks first appear on the inner wall of the restraint body. When the load continues to increase, the cracks further expand until the specimen fails rapidly, and the cracks in the restraint body penetrate the outer wall. The typical failure of the restraint body is mainly manifested as the restraint body being divided into 3 blocks by 3 radially penetrating cracks, and the included angle between adjacent cracks is approximately 120°. Based on the observed phenomena in the test, when the restraint body fails, it does not show a simple tensile failure along the circumferential thickness, but first undergoes tensile cracking in a certain range near the inner wall. Then, under the radial pressure of the grout body on the inner wall of the restraint body, a large splitting effect is generated on the uncracked restraint body, triggering an instantaneous splitting failure.
[0083] In the indoor simulation experiment in step S1, a cylindrical cement slurry body is used as the grout body to conduct a vertical loading test on the grout body, study the influence and law of various factors on the compression failure mode of the pressure - type anchor grout body, analyze the formation mechanism of different failure modes, and obtain the failure mechanism of the corresponding failure modes.
[0084] The load - displacement curve of the grout body is as Figure 6 shown.
[0085] The working principle of the present invention: In the present invention, through a research method combining indoor tests, in - situ tests, and theoretical analysis, with the compressive bearing capacity of the pressure - type anchor grout body as the core, from the compression failure mechanism of the pressure - type anchor grout body, to the analysis of the compression enhancement effect of the pressure - type anchor grout body, and further to the quantitative calculation method of the compression enhancement effect at three levels, the research on the compression enhancement effect and its quantitative calculation method of the pressure - type anti - floating anchor grout body is systematically carried out. Using the test results of indoor tests and the failure phenomena of the grout body, combined with the test results of on - site tests, a compression failure model of the pressure - type anchor grout body is established and improved, and a quantitative calculation method for the rock mass constraint effect is proposed based on this to improve the accuracy of the results.
[0086] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.
Claims
1. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body, characterized in that: The specific steps include: Step S1: Indoor simulation experiment, through indoor loading test, the effects and rules of the reinforcement diameter, the bearing plate size, the bearing plate reinforcement perforation, and the spiral reinforcement factors on the compressive bearing capacity and failure mode of the grouting body are studied; Step S2: In-situ experiment: Based on the results of the indoor model test, different strata are selected to formulate on-site in-situ test plans to implement on-site tests and inspections, and the compressive bearing capacity of the pressure-type anchor grouting body is tested in-situ and compared with the strength of the test block; Step S3: experimental data collection and processing, combined with the standard calculation method of the compressive bearing capacity of the grouting body and the indoor experimental results, further analyze the enhancement effect of the compressive bearing capacity of the pressure-type anchor grouting body; Step S4: Establish an experimental model. Based on the results of indoor and field experiments, conduct research on the calculation model of the compressive bearing capacity of the pressure-type anchor grouting body, and propose a calculation method for the compressive bearing capacity. Combined with the test results, optimize the theoretical model, further quantify the constraint effect of the calculation of the compressive bearing capacity of the pressure-type anchor grouting body, and finally propose a calculation method for the compressive bearing capacity of the pressure-type anchor grouting body.
2. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 1, characterized in that: The indoor simulation experiment in step S1 includes experimental research on the compression mechanism of pressure-type anchor grouting body under unconstrained state and experimental research on the compression mechanism of pressure-type anchor grouting body under constrained state. The experimental research on the compression mechanism of pressure-type anchor grouting body under unconstrained state combines the design parameters of pressure-type anti-floating anchor bearing body and reinforcement body in actual engineering, and carries out compression test on grouting body for grouting bodies with different bearing plate areas, spiral reinforcements, opening diameters and opening numbers.
3. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 2, characterized in that: The experimental study on the compressive mechanism of the pressure-type anchor grouting body under the constrained state is based on the experimental research results on the compressive mechanism of the pressure-type anchor grouting body under the unconstrained state. Further indoor tests on the compressive mechanism of the pressure-type anchor grouting body under the constrained state are carried out. The main research parameters are the pressure plate, tendon diameter, tendon number, constraint size, spiral tendon and constraint strength. The compressive failure law, compressive bearing capacity change law and compressive failure mode of the grouting body with different pressure plate areas, opening diameters and numbers of openings and spiral tendons under different constraint states are studied. The influence of constraint on the improvement of the strength of the grouting body is evaluated, and the influence mechanism and influence law of constraint on the compressive bearing capacity of the grouting body are revealed.
4. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 2, characterized in that: The experimental study on the compression mechanism of the pressure anchor grouting body under unconstrained state comprises the following steps: Step S11: Experimental mold making, forming a grouting casting mold by making a round tube; Step S12: pouring the grouting body, inserting a round tube at the center of the mold, and then adding cement paste into the inner cavity of the mold. After 7 days of curing, the round tube at the center is removed and the grouting body is demoulded; Step S13: Experimental loading, by grinding the top of the grouting body to be flat, and installing two sets of strain gauges on both sides of the vertical surface of the grouting body, each set of 3 strain gauges, in a horizontal state, vertically spaced, and the interval between two adjacent strain gauges is 40 mm; Step S14: During the experiment, the grouting body is subjected to a pressure test by a universal testing machine. A pressure transmission column is placed between the testing machine and the grouting body, and displacement measuring instruments are set on both sides of the pressure transmission column. The pressure test machine is used to pressurize the transmission column, and the pressure is transmitted to the grouting body until cracks appear in the grouting body. The pressure is continuously applied until the grouting body is destroyed.
5. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 2, characterized in that: The experimental study on the compression mechanism of the pressure anchor grouting body under the restrained state comprises the following steps: Step S15: Experimental mold making, forming a grouting casting mold by making a round tube; Step S16: pouring the grouting body, by inserting a round tube at the center of the mold, and then adding cement paste into the inner cavity of the mold to form the grouting body. After the grouting body is formed, the round tube is removed and the grouting body is demoulded; Step S17: constraining body construction, by sleeve two semicircular tube templates on the outside of the grouting body to form a tubular cavity, adding cement paste into the cavity between the template and the grouting body to form a constraining body, and after curing for 7 days, removing the template to obtain a grouting body in a constrained state; Step S18: Experimental loading, by grinding the top of the grouting body to be flat, and installing two sets of strain gauges on both sides of the vertical surface of the constraint body, each set of 3 strain gauges, in a horizontal state, vertically spaced, and the interval between two adjacent strain gauges is 40 mm; Step S19: During the experiment, the grouting body is pressure tested by a universal testing machine. A pressure transmission column is placed between the testing machine and the grouting body, and displacement measuring instruments are set on both sides of the pressure transmission column. The pressure test machine is used to pressurize the transmission column, and the pressure is transmitted to the grouting body until cracks appear in the grouting body. The pressure is continuously applied until the grouting body is destroyed.
6. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 1, characterized in that: The in situ experiment comprises the following steps: Step S21: Selecting a stratum and formulating an experimental plan according to different strata; Step S22: pouring the grouting body, by opening a grouting hole in the stratum, placing a round pipe at the center of the grouting circle, and then injecting cement slurry into the grouting hole, and curing for 7 days to obtain the grouting body; Step S23: experimental loading, by opening mounting holes on both sides of the stratum outside the grouting hole, and installing two sets of load sensors and displacement meters on both sides of the vertical surface of the grouting body, the load sensors and displacement meters are located inside the mounting holes; Step S24: The experiment is carried out by placing a jack on the surface of the grouting body to tension the reinforcement body, using a load sensor and a displacement meter to respectively collect the tensile displacement and tension load of the reinforcement body, and continuously applying pressure until the grouting body is destroyed.
7. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 1, characterized in that: The force formula of the grouting body is as follows: Where m 2 is the end area of the grouting body, is the internal friction angle of the grouting body, c g is the cohesion of the grouting body, σ n The inner hole is subjected to uniform compressive stress.
8. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 5, characterized in that: The inner diameter of the constraint body is d, the outer diameter is d1, and the inner hole is a cylinder with uniform pressure. The polar coordinate solution of the axisymmetric plane stress problem in elastic mechanics is as follows: ε φ is the hoop strain, E and μ are the elastic modulus and Poisson’s ratio of the constraint body, respectively, and ρ is the polar diameter of the polar coordinate system with the geometric center of the circular constraint body as the center; When the circumferential stress on the inner wall of the constraint reaches the tensile strength of the constraint, the constraint is destroyed and the grouting body is destroyed at the same time, we can get: σ t is the tensile strength of the grouting body, d1 / d=n.
9. A method for quantitatively calculating the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 1, characterized in that: The experimental model is established by using a compression cone model to calculate the compressive bearing capacity of the grouting body at the bottom of the pressure-type anchor bearing body. When the grouting body is destroyed, the bottom grouting body can be divided into a compression cone, a destruction zone and an elastic zone.
10. A quantitative calculation method for the compressive bearing capacity of a pressure-type anti-floating anchor grouting body according to claim 1, characterized in that: The indoor simulation experiment in step S1 intends to use cylindrical cement slurry as the grouting body to perform a vertical loading test on the grouting body, study the influence and law of various factors on the compressive failure mode of the pressure-type anchor grouting body, analyze the formation mechanism of different failure modes, and derive the failure mechanism of the corresponding failure mode.