Correction method for bearing capacity result of rock anchor anchorage field reduced scale model test

Abstract

The invention discloses a method for correcting a bearing capacity result of a rock anchor anchorage on-site scale model test, and belongs to the field of on-site rock mass mechanical tests, and the method comprises the following steps: carrying out a rock anchor anchorage on-site scale model test; obtaining a rock anchor anchorage bearing capacity test value and a bearing body damage contour; calculating the volume and the gravity of the rock anchor anchorage supporting body; carrying out stress analysis on the rock anchor anchorage bearing body; drawing a stress analysis chart of the rock anchor anchorage supporting body; amplifying a gravity component on the stress analysis chart of the anchorage bearing body of the rock anchor, and re-drawing a corrected stress analysis chart; and obtaining the corrected value of the anchorage bearing capacity of the rock anchor. The mechanical mechanism of the rock anchor anchorage is disclosed, and the method has the advantages of being reliable in theory and easy to operate. By correcting the bearing capacity obtained by the rock anchor anchorage field scale model test, the problem that the bearing capacity test result is conservative can be solved, the trueness of the result is improved, the guiding significance of the test on engineering is enhanced, and the popularization and application of the rock anchor anchorage field scale model test in engineering practice are promoted.

Description

Technical Field

[0001] The invention relates to the technical field of on-site rock mass mechanics tests, and in particular to a method for correcting bearing capacity results of an on-site scaled model test of a rock anchor. Background Art

[0002] Anchorage is an important basic load-bearing structure of suspension bridge. In the past, due to the constraints of economic and technological development, suspension bridge anchorage usually adopts gravity anchorage and tunnel anchorage, and has accumulated rich experience and research and technical achievements in gravity anchorage and tunnel anchorage engineering application. Compared with gravity anchorage and tunnel anchorage, rock anchorage is a new type of anchorage structure. It is to cast reinforced concrete anchor plates on the surface of the mountain, cast reinforced concrete anchor plates inside the mountain after excavation, and then make dozens of holes for burying prestressed anchor cables between the front and rear anchor plates. By applying prestress to the rock mass clamped by the front and rear anchor plates, a load-bearing structure that bears the tension of the main cable of the suspension bridge is formed. It has the significant advantages of small engineering volume, economy and environmental protection, and makes full use of the bearing capacity of the rock mass, but the structure is novel and the mechanical mechanism is complex. At present, there are not many cases of using rock anchor schemes abroad, and China has only begun to explore the use of this anchor scheme. How to demonstrate the bearing capacity and safety and stability of rock anchors is a technical direction that urgently needs to be focused on.

[0003] At present, the evaluation of the bearing capacity and safety stability of rock anchors is usually studied by theoretical calculation analysis, on-site scaled model test and numerical simulation. Referring to the research history and experience of tunnel anchors, conducting on-site scaled model test of rock anchors is a reliable method to intuitively obtain the bearing capacity of rock anchors. However, the on-site scaled model test of rock anchors is based on the similarity principle of elastic mechanics. It requires that the model and the prototype are made of the same material, and the geometric size of the model is reduced by a certain proportion from the structural size of the prototype. The test load is applied to the model according to the similarity relationship, but the influence of the model's own gravity after scaling is ignored. According to the similarity principle, the gravity of the on-site model of the rock anchor after scaling is reduced more than the theoretical value, and gravity is a resistance force for the entire force system of the rock anchor, which causes the bearing capacity results obtained by the on-site scaled model test of the rock anchor to be smaller than the actual value. How to reduce the difference between the rock anchor field scaled model test technology in truly describing the mechanical properties of the prototype rock anchor, improve the authenticity of the bearing capacity results, and enhance the guiding significance of the rock anchor field scaled model test for engineering is particularly urgent and important. Through extensive literature review, there has been no report on the improvement of the rock anchor field scaled model test technology or the correction of the results. Due to the limitations of the field rock mechanics test method, it is difficult to improve the field scaled model test construction and loading technology. Therefore, it is of great value to invent a correction method for the bearing capacity results after the test based on theoretical derivation. Summary of the invention

[0004] In order to solve the problem in the prior art that the bearing capacity results obtained from the existing rock anchor anchoring on-site scaled model test are conservative, the present invention provides a method for correcting the bearing capacity results of the rock anchor anchoring on-site scaled model test.

[0005] In order to realize the above technical solution, the present invention provides a method for correcting the bearing capacity results of a rock anchor on-site scaled model test, comprising the steps of:

[0006] S1: Construct a scaled model of rock anchor and conduct on-site scaled model test of rock anchor;

[0007] S2: Obtain the test value of the rock anchor bearing capacity and the failure contour of the bearing body;

[0008] S3: Calculate the volume and gravity of the rock anchor bearing body;

[0009] S4: Conduct stress analysis on the rock anchor bearing body;

[0010] S5: Draw the force analysis diagram of the rock anchor bearing body;

[0011] S6: Enlarge the gravity component on the force analysis diagram of the rock anchor bearing body and redraw the corrected force analysis diagram;

[0013] S7: Obtain the correction value of the rock anchor bearing capacity.

[0014] Furthermore, step S1 includes sub-steps:

[0015] S1.1: Design a scaled model of rock anchor according to the similarity principle of elastic mechanics. Select a location with representative engineering geological conditions in the actual bridge rock anchor project area and build a rock anchor model with a scale ratio of 1:N according to the similarity principle. When the body force is not considered, the similarity relationship between the model and the prototype is:

[0016] Geometry:

[0017] Modulus of elasticity: E m =E p

[0018] Strength: R m =R p

[0019] Load:

[0020] S1.2: Install loading and measuring equipment;

[0021] S1.3: Load and measure the scaled model of the rock anchor until the model fails and draw the load-displacement curve.

[0022] Furthermore, step S2 includes sub-steps:

[0023] S2.1: The maximum loading load is obtained through the load-displacement curve measured during the loading process of the scaled rock anchor model, and is determined as the bearing capacity of the scaled rock anchor model;

[0024] S2.2: By analyzing the time and space of the surface cracks exposed inside and outside the rock anchor model, the failure mode of the rock anchor and the failure profile of the bearing body are generalized.

[0025] Furthermore, step S3 includes sub-steps:

[0026] S3.1: Draw the three-dimensional shape of the rock anchor bearing body through the generalized rock anchor bearing body failure contour, and calculate the volume of the rock anchor bearing body;

[0027] S3.2: Based on the calculated volume of the rock anchor bearing body, the density of the rock mass of the rock anchor is obtained by consulting the geological survey data, and the gravity of the rock anchor bearing body is calculated using the following formula:

[0028] W=Vρg

[0029] Further, step S4 includes sub-steps:

[0030] S4.1: Take the rock anchor bearing body as an independent unit and treat it as a rigid body;

[0031] S4.2: Analysis of the additional load F applied to the anchor bearing element during the test loading 附 , the weight W of the rock anchor bearing body itself and the resistance F of the external rock mass to the rock anchor bearing body 抗 ;

[0032] S4.3: Indicate the additional load F obtained in step S2 whose magnitude and direction are known. 附 .

[0033] S4.4: marking the self-weight W of the rock anchor bearing body obtained in step S3, the magnitude and direction of which are known;

[0034] Further, step S5 includes sub-steps:

[0035] S5.1: It is assumed that when the rock anchor system fails, all external forces acting on the rock anchor bearing body reach a state of mechanical equilibrium;

[0036] S5.2: Draw a force analysis diagram of the rock anchor bearing body and add F 附 and W are drawn end to end;

[0037] S5.3: According to the triangle closure condition principle of the external force on the system in limit equilibrium, obtain the resistance F of the external rock mass to the rock anchor bearing body 抗 .

[0038] Further, step S6 includes sub-steps:

[0039] S6.1: On the force analysis diagram obtained in step S5.3, the weight W of the rock anchor bearing body itself is magnified by N times and marked with W2;

[0040] S6.2: Determine the new resultant force F by graphical method;

[0041] S6.3: Decompose the resultant force F along the rock anchor test loading direction and the perpendicular direction to the force F 附2 and F1.

[0042] S6.4: The resistance of the original external rock mass to the rock anchor bearing body F 抗 The resistance growth F1 of the external rock mass to the rock anchor bearing body after the gravity is amplified is vector-summed according to the drawing method to obtain the total resistance F1 of the external rock mass to the rock anchor bearing body after the gravity is amplified. 抗2 ;

[0043] S6.5: Based on the obtained W2, F 附2 and F 抗2 Redraw the revised force analysis diagram.

[0044] Further, step S7 includes sub-steps:

[0045] S7.1: By comparing the F on the force analysis diagram before and after correction 附 and F 附2 , it is known that F 附 According to the principle of proportion, determine F 附2 size;

[0046] S7.2: The F 附2 Determined as the correction value of the rock anchor bearing capacity.

[0047] In summary, the present invention has the following beneficial effects compared with the prior art:

[0048] Based on theoretical analysis and mechanical derivation, the present invention adopts a graphical method to correct the bearing capacity results of the on-site scaled model test of the rock anchor, solves the problem that the bearing capacity test results are conservative, improves the authenticity of the results, enhances the guiding significance of the test to the project, and further promotes the promotion and application of the on-site scaled model test of the rock anchor in engineering practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0050] Figure 1 A flow chart of a method for correcting bearing capacity results of a rock anchor on-site scaled model test provided by the present invention;

[0051] Figure 2 It is a schematic diagram of carrying out a scaled model test of a rock anchor in an embodiment of the present invention;

[0052] Figure 3 A bearing body failure contour effect diagram obtained by a field scaled model test of a rock anchor in an embodiment of the present invention;

[0053] Figure 4 It is a force analysis diagram of the rock anchor bearing body in an embodiment of the present invention;

[0054] Figure 5 This is a force analysis diagram of the modified rock anchor bearing body in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form can also include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0057] See also Figure 1 As shown, the present invention provides a method for correcting the bearing capacity results of a rock anchor on-site scaled model test, comprising the steps of:

[0058] S1: Construct a scaled model of rock anchor and conduct on-site scaled model test of rock anchor;

[0059] S2: Obtain the test value of the rock anchor bearing capacity and the failure contour of the bearing body;

[0060] S3: Calculate the volume and gravity of the rock anchor bearing body;

[0061] S4: Conduct stress analysis on the rock anchor bearing body;

[0062] S5: Draw the force analysis diagram of the rock anchor bearing body;

[0063] S6: Enlarge the gravity component on the force analysis diagram of the rock anchor bearing body and redraw the corrected force analysis diagram;

[0064] S7: Obtain the correction value of the rock anchor bearing capacity.

[0065] As a preferred embodiment, step S1 includes sub-steps:

[0066] S1.1: Design a scaled model of rock anchor according to the similarity principle of elastic mechanics. Select a location with representative engineering geological conditions in the actual bridge rock anchor project area and build a rock anchor model with a scale ratio of 1:N according to the similarity principle. When the body force is not considered, the similarity relationship between the model and the prototype is:

[0067] Geometry:

[0068] Modulus of elasticity: E m =E p

[0069] Strength: R m =R p

[0070] Load:

[0071] Where: L m and L p are the structural geometric length dimensions of the model and prototype respectively; E m and E p are the elastic modulus of the model and prototype materials respectively; R m and R p are the strength characteristic values ​​of the model and prototype respectively; N m and N p are the load values ​​applied to the model and prototype respectively; N is the scale ratio.

[0072] S1.2: Install loading and measuring equipment;

[0073] S1.3: Load and measure the scaled model of the rock anchor until the model fails and draw the load-displacement curve.

[0074] As a preferred embodiment, step S2 includes the following sub-steps:

[0075] S2.1: The maximum loading load is obtained through the load-displacement curve measured during the loading process of the scaled rock anchor model, and is determined as the bearing capacity of the scaled rock anchor model;

[0076] S2.2: By analyzing the time and space of the surface cracks exposed inside and outside the rock anchor model, the failure mode of the rock anchor and the failure profile of the bearing body are generalized.

[0077] As a preferred embodiment, step S3 includes sub-steps:

[0078] S3.1: Draw the three-dimensional shape of the rock anchor bearing body through the generalized rock anchor bearing body failure contour, and calculate the volume of the rock anchor bearing body;

[0079] S3.2: Based on the calculated volume of the rock anchor bearing body, consult the geological survey data to obtain the density of the rock anchor rock mass, and use the following formula to calculate the gravity of the rock anchor bearing body:

[0080] W=Vρg

[0081] Where: W is the gravity of the rock anchor bearing body, V is the volume of the rock anchor bearing body, ρ is the density of the rock mass of the rock anchor, and g is the gravitational acceleration.

[0082] As a preferred embodiment, step S4 includes the following sub-steps:

[0083] S4.1: Take the rock anchor bearing body as an independent unit and treat it as a rigid body;

[0084] S4.2: Analysis of the additional load F applied to the anchor bearing element during the test loading 附 , the weight W of the rock anchor bearing body itself and the resistance F of the external rock mass to the rock anchor bearing body 抗 These three forces constitute all the external forces on the rock anchor bearing body, among which F 抗 It includes the tensile stress, compressive stress and shear stress on the four surfaces of the rock anchor bearing body failure contour;

[0085] S4.3: Indicate the additional load F obtained in step S2 whose magnitude and direction are known. 附 .

[0086] S4.4: marking the self-weight W of the rock anchor bearing body obtained in step S3, the magnitude and direction of which are known;

[0087] As a preferred embodiment, step S5 includes sub-steps:

[0088] S5.1: It is assumed that when the rock anchor system fails, all failure surfaces on the failure contour of the rock anchor bearing body reach the limit state at the same time. According to the limit equilibrium principle, all external forces acting on the rock anchor bearing body reach the mechanical equilibrium state.

[0089] S5.2: Draw a force analysis diagram of the rock anchor bearing body and add F 附and W are drawn end to end;

[0090] S5.3: According to the triangle closure condition principle of the external force on the system in limit equilibrium, obtain the resistance F of the external rock mass to the rock anchor bearing body 抗 The resistance is the total vector sum of all forces exerted by the external rock mass on the rock anchor bearing body, without distinguishing the stress distribution and stress resultant on each failure surface of the rock anchor bearing body.

[0091] As a preferred embodiment, step S6 includes the following sub-steps:

[0092] S6.1: According to the similarity principle, the gravity of the rock anchor model only needs to be reduced by N 2 times, which is actually reduced by N 3 times, which is reduced by N. On the force analysis diagram obtained in step S5.3, the weight W of the rock anchor bearing body itself is magnified by N times and marked as W2;

[0093] S6.2: Assume that the failure mode of the rock anchor model remains unchanged after the self-weight stress increases, that is, the failure contour of the rock anchor bearing body remains unchanged. Similarly, according to the principle that the external force on the system meets the triangle closure condition at the limit equilibrium, the magnitude and direction of the amplified rock anchor bearing body's own gravity W2 and the resistance F of the external rock mass to the rock anchor bearing body are known. 抗 The magnitude and direction of the new resultant force F can be obtained by graphical construction;

[0094] S6.3: The resultant force F actually consists of two parts. One part is the additional load that the rock anchor model can bear after the gravity is amplified, and the other part is the increase in the resistance of the external rock mass to the rock anchor bearing body after the gravity is amplified. The resultant force F is decomposed along the loading direction of the rock anchor test and its vertical direction into force F 附2 and F1.

[0095] S6.4: The resistance of the original external rock mass to the rock anchor bearing body F 抗 The resistance growth F1 of the external rock mass to the rock anchor bearing body after the gravity is amplified is vector-summed according to the drawing method to obtain the total resistance F1 of the external rock mass to the rock anchor bearing body after the gravity is amplified. 抗2 , compared with F 抗2 and F 抗 , F 抗2 The size of F 抗 The magnitude of the rock anchor model is large, but in different directions. Its essence is the influence of various distributed stresses on the failure contour surface of the rock anchor bearing body after the deadweight stress increases.

[0096] S6.5: Based on the obtained W2, F 附2 and F 抗2 Redraw the revised force analysis diagram.

[0097] As a preferred embodiment, step S7 includes sub-steps:

[0098] S7.1: By comparing the F on the force analysis diagram before and after correction 附 and F 附2 , it is known that F 附 According to the principle of proportion, determine F 附2 size;

[0099] S7.2: The F 附2 Determined as the correction value of the rock anchor bearing capacity.

[0100] In order to prove the reliability of the results obtained in the model correction process of the correction method for the bearing capacity results of the rock anchor anchorage field scaled model test provided by the present invention, this method is demonstrated by the following examples:

[0101] The main span of a bridge is 1488mm, and the maximum tension of a single main cable is 324346kN. A rock anchor anchoring scheme was adopted on one bank, and the bedrock is slightly weathered dacite. The inclination angle between the axis of the rock anchor body and the horizontal plane is 37°, the oblique length is 40m, and the maximum burial depth after excavation is 48.4m. 34 high-precision prestressed anchor rock holes are made in a plum blossom shape in each rock anchor body, and several φ15.2mm epoxy steel strand cables are installed in each rock hole. The front and rear anchor plates are both C55 reinforced concrete structures.

[0102] like Figure 2 As shown in the figure, slightly weathered dacite strata are used as the surrounding rock of the model anchorage near the anchorage engineering area of ​​the bridge. The surface and the rear anchorage chamber rock mass are excavated according to the size of the real bridge rock anchorage at 1:10, so that the inclined length of the rock anchorage is 4m, the inclination angle of the rock anchorage to the horizontal direction is 37°, and the azimuth angle of the rock anchorage is 58°, which is consistent with the real bridge anchorage. The maximum vertical burial depth of the model anchorage is 4.84m. Then, two 1.3m wide × 1.4m high × 0.4m thick C55 reinforced concrete anchorage plates are cast on the front anchorage surface, and one 6.2m wide × 1.5m high × 0.4m thick C55 reinforced concrete anchorage plate is cast on the rear anchorage surface. Finally, 12 φ76mm holes are made in 2 rows and 6 columns on the front and rear anchorage plates to apply prestress to the front and rear anchorage plates. Seven unbonded φ15.2mm prestressed steel strands were installed in each borehole, and 12 150-ton hollow hydraulic jacks and prestressed steel strands were installed on the front anchor surface to form a prestressed loading system. Twenty-eight 300-ton hydraulic jacks were installed on the rear anchor surface to form a rear anchor surface thrust loading system. Fourteen surface displacement meters were installed on the front and rear anchor surfaces, and six borehole multi-point displacement meters were installed deep in the rock mass to test the deformation of the rock anchor.

[0103] The scaled model of rock anchor was loaded and measured. When loaded to 45408kN, the first visible crack appeared on the ground surface; when loaded to 71356kN, the number and width of surface cracks increased, but the pressure and deformation remained stable; when loaded from 71356kN to 77843kN, the deformation increased rapidly, and the pressure dropped sharply with the increase of deformation. The pressure fluctuated violently and could not remain stable. At the same time, the concrete of the rear anchor plate was broken and damaged at the jack's point of application. The load-displacement curve shows that the bearing capacity of the rock anchor model is 71356kN, and the direction is 37° upward.

[0104] Many surface cracks appeared in the scaled model of rock anchor during loading. Through the temporal and spatial analysis of the occurrence of cracks, it was generalized into a failure mode in which the rear edge tensile crack surface penetrated, the two sides of the crack surface tracked the steep angle joint tensile shear fracture penetration, and the bottom sliding surface tracked the slow angle joint dislocation to form an overall failure. The rock anchor failure contour and rock anchor bearing body were obtained, such as Figure 3 As shown in Figure 2, the volume of the rock anchor bearing body is calculated to be 107m 3 .

[0105] According to the geological survey report, the density of slightly weathered dacite is 2550kg / m 3 The weight of the rock anchor bearing body is calculated to be 2672 kN, and the direction is vertically downward.

[0106] like Figure 4 As shown, the force analysis of the rock anchor bearing body is carried out. Under the limit equilibrium state, the rock anchor bearing body is subjected to a gravity of 2672kN in the vertical downward direction, and an additional load of 71356kN, which is 11 times the design load, in the oblique upward direction of 37°. A force analysis diagram of the rock anchor bearing body is drawn, and the graphical method is used to obtain the resistance of the external rock mass to the rock anchor bearing body, which is 69781kN in the oblique downward direction of 35°.

[0107] like Figure 5 As shown in the figure, the gravity component on the force analysis diagram of the rock anchor bearing body is magnified 10 times, and the revised force analysis diagram is redrawn. The additional load on the rock anchor bearing body is obtained by graphical method as 85828kN.

[0108] 85828kN is determined as the corrected bearing capacity of rock anchor, that is, the corrected bearing capacity of rock anchor is 85828kN, which is 13.2 times the design load. Compared with before correction, the bearing capacity is increased by 20%, which provides guidance for the safety evaluation and optimization design of rock anchor. The essence of the increase in bearing capacity after correction by this method is the increase in its own gravity resistance component, and the increase in shear strength on the failure contour surface due to the increase in gravity is not taken into account. Objectively, due to the complex stress distribution on the shear failure surface, it is difficult to accurately calculate the increase in shear strength on the failure contour surface due to the increase in gravity.

[0109] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for correcting the bearing capacity results of a rock anchor on-site scaled model test, characterized in that: Includes steps: S1: Construct a scaled model of rock anchor and conduct on-site scaled model test of rock anchor; S2: Obtain the test value of the rock anchor bearing capacity and the failure contour of the bearing body; S3: Calculate the volume and gravity of the rock anchor bearing body; S4: Conduct stress analysis on the rock anchor bearing body; S5: Draw the force analysis diagram of the rock anchor bearing body; S6: Enlarge the gravity component on the force analysis diagram of the rock anchor bearing body and redraw the corrected force analysis diagram; S7: Obtain the correction value of the rock anchor bearing capacity.

2. The method for correcting the bearing capacity results of the on-site scaled model test of rock anchor according to claim 1 is characterized in that: Step S1 includes sub-steps: S1.1: Design a scaled model of rock anchor according to the similarity principle of elastic mechanics. Select a location with representative engineering geological conditions in the actual bridge rock anchor project area and build a rock anchor model with a scale ratio of 1:N according to the similarity principle. When the body force is not considered, the similarity relationship between the model and the prototype is: Geometry: Elastic modulus: E m =E p Strength: R m =R p Load: S1.2: Install loading and measuring equipment; S1.3: Load and measure the scaled model of the rock anchor until the model fails and draw the load-displacement curve.

3. The method for correcting the bearing capacity results of a rock anchor on-site scaled model test according to claim 1, characterized in that: Step S2 includes the following sub-steps: S2.1: The maximum loading load is obtained through the load-displacement curve measured during the loading process of the scaled rock anchor model, and is determined as the bearing capacity of the scaled rock anchor model; S2.2: By analyzing the time and space of the surface cracks exposed inside and outside the rock anchor model, the failure mode of the rock anchor and the failure profile of the bearing body are generalized.

4. The method for correcting the bearing capacity results of a rock anchor on-site scaled model test according to claim 1 is characterized in that: Step S3 includes sub-steps: S3.1: Draw the three-dimensional shape of the rock anchor bearing body through the generalized rock anchor bearing body failure contour, and calculate the volume of the rock anchor bearing body; S3.2: Based on the calculated volume of the rock anchor bearing body, consult the geological survey data to obtain the density of the rock anchor rock mass, and use the following formula to calculate the gravity of the rock anchor bearing body: W=Vρg.

5. The method for correcting the bearing capacity results of a rock anchor on-site scaled model test according to claim 1 is characterized in that: Step S4 includes the sub-steps of: S4.1: Take the rock anchor bearing body as an independent unit and treat it as a rigid body; S4.2: Analysis of the additional load F applied to the anchor bearing element during the test loading 附 , the weight W of the rock anchor bearing body itself and the resistance F of the external rock mass to the rock anchor bearing body 抗 ; S4.4: Label the additional load obtained in step S2. The additional load F is known in magnitude and direction. 附 ; S4.3: Indicate the magnitude and direction of the known rock anchor bearing body's own weight W obtained in step S3.

6. The method for correcting the bearing capacity results of a rock anchor on-site scaled model test according to claim 1 is characterized in that: Step S5 includes sub-steps: S5.1: It is assumed that when the rock anchor system fails, all external forces acting on the rock anchor bearing body reach a state of mechanical equilibrium; S5.2: Draw a force analysis diagram of the rock anchor bearing body and add F 附 and W are drawn end to end; S5.3: According to the triangle closure condition principle of the external force on the system in limit equilibrium, obtain the resistance F of the external rock mass to the rock anchor bearing body 抗 .

7. A method for correcting the bearing capacity results of a rock anchor on-site scaled model test according to claim 6, characterized in that: Step S6 includes the sub-steps of: S6.1: On the force analysis diagram obtained in step S5.3, the weight W of the rock anchor bearing body itself is magnified by N times and marked with W2; S6.2: Determine the new resultant force F by graphical method; S6.3: Decompose the resultant force F along the rock anchor test loading direction and the perpendicular direction to the force F 附2 and F1; S6.4: The resistance of the original external rock mass to the rock anchor bearing body F 抗 The resistance growth F1 of the external rock mass to the rock anchor bearing body after the gravity is amplified is vector-summed according to the drawing method to obtain the total resistance F1 of the external rock mass to the rock anchor bearing body after the gravity is amplified. 抗2 ; S6.5: Based on the obtained W2, F 附2 and F 抗2 Redraw the revised force analysis diagram.

8. The method for correcting the bearing capacity results of a rock anchor on-site scaled model test according to claim 7, characterized in that: Step S7 includes sub-steps: S7.1: By comparing the F on the force analysis diagram before and after correction 附 and F 附2 , it is known that F 附 According to the principle of proportion, determine F 附2 size; S7.2: The F 附2 Determined as the correction value of the rock anchor bearing capacity.

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