Reinforced earth retaining wall tension testing device and testing method

Abstract

The present application belongs to the technical field of geotechnical engineering, and discloses a reinforced soil retaining wall's reinforcement material down pull testing device and testing method. The rolling friction force between the roller and the longitudinal beam at the back end of the model box replaces the sliding friction force of the direct contact between the retaining wall module and the longitudinal beam at the back end of the model box. There is no contact between the existing retaining wall and the side wall of the model box, so there is no friction force between them. When monitoring the down pull of the reinforcement material, the loss caused by the friction force is effectively reduced. The down pull obtained by the present application can provide clear evidence for the strain concentration phenomenon at the connection between the reinforcement material and the existing retaining wall, and promote the innovation of the reinforcement material strength design method. The total down pull obtained by the testing can be used as an exact and additional load, which is input into the calculation of the stability of the existing retaining wall foundation, and is used for evaluating the stability and deformation of the bearing capacity of the foundation under the existing retaining wall.

Description

Technical Field

[0001] This invention belongs to the field of geotechnical engineering technology, and in particular relates to a device and method for testing the tensile strength of the reinforcing bars in a reinforced soil retaining wall. Background Technology

[0002] Reinforced soil retaining walls, as a flexible retaining structure with good stress-deformation characteristics, low cost, aesthetic appearance, and excellent seismic performance, are widely used in highway embankment subgrades. However, due to space constraints in some sites, the length of the reinforcement in the reinforced soil retaining wall does not meet the minimum length specified in the code (0.7 times the wall height), resulting in insufficient tensile stability of the reinforcement and subsequent instability failure. In this situation, current relevant codes and engineering practices address the issue by connecting the ends of the reinforcement in the reinforced soil retaining wall to the existing highway retaining wall.

[0003] Due to the weight of the fill soil and the overlying load, differential settlement will occur at the connection between the reinforced soil retaining wall and the existing retaining wall. The newly built reinforced soil retaining wall will experience significant settlement, while the existing retaining wall will experience minimal settlement. This differential settlement will cause the reinforcement material connected to the existing retaining wall to exert a very large downward force on it, which may lead to shear failure of the foundation soil beneath the existing retaining wall, affecting the stability and safety of the entire roadbed structure. Therefore, it is essential to accurately assess and measure the magnitude of the total downward force exerted by the reinforcement material on the existing retaining wall.

[0004] The most reliable method for testing the tensile strength of reinforcing bars is to use a full-scale indoor test, which is also the method used in this invention. However, current full-scale tests for measuring the tensile strength of reinforcing bars still face the following challenges:

[0005] 1. Existing retaining walls experience complex stresses. The combined force of the sand and reinforcement in a reinforced soil retaining wall generates a horizontal tensile force at the top and a horizontal thrust at the bottom, with the latter exerting a greater thrust. Therefore, the overall force is a horizontal thrust. To prevent horizontal displacement, the existing retaining wall must be provided with horizontal support. Currently, in laboratory testing, the existing retaining wall is constructed as a single, integral structure and placed directly against a model box. However, when the existing retaining wall is in direct contact with the sidewall of the model box, the friction between them is enormous. This significant friction offsets most of the downward tension exerted by the reinforcement on the existing retaining wall, leading to highly inaccurate testing.

[0006] 2. To study the magnitude of the tensile force of reinforcing bars under various factors (such as the spacing between reinforcing bars), a large number of full-scale tests are often required. Retaining wall modules constructed from single concrete masonry blocks are large in volume, difficult to hoist, and inconvenient to construct. Retaining wall modules assembled from multiple concrete masonry blocks are difficult to stabilize because they are subjected to horizontal tensile forces at the top and horizontal thrust forces at the bottom.

[0007] Therefore, the present invention provides a device and method for testing the tensile strength of the reinforcing bars in a reinforced soil retaining wall to overcome the above-mentioned problems. Summary of the Invention

[0008] The purpose of this invention is to provide a device for testing the tensile force of reinforced soil retaining walls, so as to accurately evaluate the magnitude of the total tensile force of the reinforcement in the reinforced soil retaining wall on the existing retaining wall through full-scale tests in the laboratory.

[0009] Another objective of this invention is to provide a measurement method for the above-described device to calculate the total tensile force of the reinforcing bars, which is then used as a precise additional load for calculating the stability of existing retaining wall foundations.

[0010] The technical solution adopted in this invention is a tensile testing device for the reinforcing bars of a reinforced soil retaining wall, comprising a model box. The model box has a foundation located at its bottom near the front end, upon which wall modules are stacked layer by layer. A weighing platform is located at the bottom of the model box near the rear end, upon which retaining wall modules are stacked.

[0011] The longitudinal section of the retaining wall module is a right-angled trapezoidal structure, with steel hooks provided on its inclined surface and its vertical surface used to fix steel plates.

[0012] Support frames are provided at both the upper and lower ends of the steel plate, and the rollers are mounted on the support frames via rotating shafts. The rollers are in contact with the longitudinal beam at the rear end of the model box.

[0013] Furthermore, the front, rear, and top of the model box are all open, with a rear longitudinal beam and a cross beam at the rear opening and a top cross beam at the top opening weld. The side walls of the model box on both sides are closed surfaces, and a side wall longitudinal beam is provided on the side wall. The rear longitudinal beam and the side wall longitudinal beam are both perpendicular to the ground.

[0014] Furthermore, the space between the wall module and the retaining wall module is filled with sand, and a loading plate is set on the top surface of the uppermost layer of sand. The loading plate is formed by splicing multiple rectangular concrete slabs, and a jack is fixed below the top beam of the model box. The other end of the jack is in contact with the loading plate.

[0015] Furthermore, the steel plate is provided with two rows of bolt holes, and the bolts pass through the upper and lower rows of bolt holes of the steel plate respectively. The nuts are tightened to fix the upper and lower ends of the steel plate to the lower and upper sides of the vertical surfaces of the two adjacent retaining wall modules respectively.

[0016] Furthermore, reinforcing bars are laid horizontally in the sand, with one end of the reinforcing bar fixed to a steel hook and the other end extending between the upper and lower wall modules, and fixed by the friction between the wall modules and the gravel.

[0017] Furthermore, geotextile is used to cover the gaps between the retaining wall module and the side wall of the model box, as well as the gaps between the weighing platform and the side wall of the model box.

[0018] Furthermore, the weighing platform is also equipped with a load sensor, and the load reading instrument is connected to the load sensor.

[0019] Furthermore, the wall module is a hollow structure that runs vertically through the wall, with the hollowed-out area in the middle filled with gravel.

[0020] The technical solution of the present invention also includes a method for testing the tensile force of reinforcement in a reinforced soil retaining wall, using a device for testing the tensile force of reinforcement in a reinforced soil retaining wall, the steps of which include:

[0021] S1. First, use a crane to place the weighing platform inside the model box. Then, connect the first steel plate with rollers to the first retaining wall module and hoist the first retaining wall module with steel plate and rollers onto the weighing platform.

[0022] S2, connect the second steel plate with rollers to the second retaining wall module, and hoist the second retaining wall module with steel plate and rollers onto the first retaining wall module. The rollers contact the longitudinal beam at the rear end of the model box. Then connect the steel plate of the first retaining wall module to the second retaining wall module, so that the first retaining wall module and the second retaining wall module are connected by steel plate.

[0023] S3. Following the methods of steps S1 to S2, install multiple retaining wall modules and corresponding steel plates in sequence until the design elevation is reached, thereby connecting all retaining wall modules into a whole. Read and record the data through a load reading instrument. At this time, the data is the overall mass M1 of the existing retaining wall module. Then, use geotextile to cover the gaps between the retaining wall module and the side wall of the model box, as well as between the weighing platform and the side wall of the model box.

[0024] S4. Place the foundation in the model box near the front end, then place the wall module on the foundation and fill the hollowed-out area in the middle of the wall module with gravel. Then fill the space between the retaining wall module and the wall module with sand. When the sand is filled to the corresponding layer of reinforcement, install the reinforcement of that layer. Then place the next wall module and continue to fill the sand on top of the installed reinforcement. Repeat this process until the design height of the reinforced soil retaining wall is reached. Read the mass M2 on the load reading instrument.

[0025] S5 applies load to the sand using jacks and a loading plate. And read the third mass M using a load cell. p ;

[0026] S6, based on the first mass M1, the second mass M2 and the third mass M pIn addition to the dimensions and material properties of the reinforced soil retaining wall, the tensile force of the reinforcement (6) per unit width on the retaining wall module (4) is calculated. When the load is 0, the calculation method is as follows:

[0027] ;

[0028] Under load Under action, the downward force of the reinforcing bar (6) per unit width F The calculation formula is:

[0029] ;

[0030] In the formula, The readings are from the load reading instrument under the self-weight of the sand. For load Load reading under load For the overall quality of the retaining wall module, The density of sandy soil, The height from the top surface of the weighing platform to the top surface of the sand. Let g be the difference between the bottom width and the top width of the multiple retaining wall modules along the first horizontal direction, and g be the acceleration due to gravity. The load applied to the jack The length of the retaining wall module along the second horizontal direction, which is perpendicular to the first horizontal direction.

[0031] The beneficial effects of this invention are:

[0032] 1. In this invention, the existing retaining wall and the side wall of the model box do not contact each other, so there is no friction between them. When monitoring the tensile force of the reinforcing bars, the loss caused by friction is effectively reduced.

[0033] 2. In this invention, the existing retaining wall contacts the rear end of the model box through rollers, which not only provides horizontal support for the existing retaining wall, but also replaces the sliding friction of direct contact in the prior art with the rolling friction of the rollers, which greatly reduces the friction force and reduces the loss caused by friction force when monitoring the downward force of the reinforcing bars.

[0034] 3. The wall module design and reinforcement laying sequence provided by this invention can ensure that the reinforcement is taut when laid in sand, which is convenient for construction and can avoid the loss of reinforcement tension and excessive deformation of the wall module caused by reinforcement slack.

[0035] 4. The existing retaining wall of this invention is a modular type, composed of stacked retaining wall modules, which reduces installation difficulties. The connection of the retaining wall modules can effectively cope with the complex mechanical conditions of the existing retaining wall being under tension at the top and compression at the bottom, ensuring its stability. This ensures that the mechanical properties of the reinforced soil retaining wall in front of the existing retaining wall are not affected by the deformation of the existing retaining wall. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic diagram of the planar structure of the testing device of the present invention.

[0038] Figure 2 This is a three-dimensional structural schematic diagram of the testing device of the present invention.

[0039] Figure 3 The wall module of the present invention is shown in (a) as a top view and (b) as a vertical sectional view.

[0040] Figure 4 This is a schematic diagram of the connection between the two retaining wall modules in this invention.

[0041] Figure 5 This is a schematic diagram of the steel plate and rollers connecting the retaining wall module of the present invention.

[0042] Figure 6 This is a schematic diagram of the geotextile covering gap in the present invention, wherein (a) is a schematic diagram of the first gap between the geotextile covering retaining wall module and the side wall of the model box, and (b) is a schematic diagram of the second gap between the weighing platform and the side wall of the model box.

[0043] Figure 7 This is a flowchart of the method for testing the tensile strength of the reinforcing bars in the reinforced soil retaining wall of this invention.

[0044] In the diagram, 1. Model box, 2. Foundation, 3. Wall module, 4. Retaining wall module, 5. Sand, 6. Reinforcing steel, 7. Reinforcing steel hook, 8. Bolt, 9. Loading plate, 10. Jack, 11. Weighing platform, 12. Load reading instrument, 13. Roller, 14. Nut, 15. Steel plate, 16. Bolt hole, 17. Geotextile, 18. Gravel, 19. Side wall of model box, 20. Top beam of model box, 21. Rear longitudinal beam of model box, 22. Side longitudinal beam of model box. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] An embodiment of the present invention provides a tensile testing device for the reinforcing bars of a reinforced soil retaining wall, comprising a model box 1. The front and rear ends of the model box 1 are open. The front opening is used for personnel to enter and exit and for transporting materials such as the foundation 2, wall modules 3, and reinforcing bars 6 required for the construction of the reinforced soil retaining wall. The rear opening is welded with a longitudinal beam 21 and a crossbeam. The opening provides operating space for connecting two adjacent retaining wall modules 4. The top of the model box 1 is also open, and a top crossbeam 20 is welded to the top opening.

[0047] like Figure 2 As shown, the side walls 19 of the model box 1 on both sides are closed surfaces and are welded with longitudinal beams 22. For easy observation, one of the side walls can be designed to be transparent.

[0048] The rear longitudinal beam 21 and the side longitudinal beam 22 of the model box are both perpendicular to the ground.

[0049] Preferably, all the horizontal and vertical beams of the model box 1 are square tubes with a cross section of 120mm×120mm and a wall thickness of 5mm.

[0050] like Figure 1 As shown, a foundation 2 is set at the bottom near the front end of the model box 1, and wall modules 3 are stacked layer by layer on the foundation 2; a weighing platform 11 is set at the bottom near the rear end of the model box 1, and retaining wall modules 4 are stacked on the weighing platform 11. Sand 5 is filled between the wall modules 3 and the retaining wall modules 4.

[0051] The side of the weighing platform 11 that contacts the sand 5 is a closed surface, which can prevent the sand 5 from leaking into it. A load sensor is also installed inside the weighing platform 11. The load reading instrument 12 is connected to the load sensor and can directly read the mass above the weighing platform 11.

[0052] The longitudinal section of the retaining wall module 4 is a right-angled trapezoidal structure, and a steel bar hook 7 is provided on its inclined surface. Its vertical surface is used to fix the steel plate 15. The steel bar hook 7 is used to fix the reinforcing bar 6.

[0053] The retaining wall module 4 can also adopt a rectangular structure, and when it adopts a trapezoidal structure, the inclination angle of its slope can be set according to specific needs.

[0054] The steel plate 15 is provided with two rows of bolt holes 16. Bolts 8 pass through the upper and lower rows of bolt holes 16 of the steel plate 15 respectively, and nuts 14 are tightened to fix the upper and lower ends of the steel plate 15 to the lower and upper sides of the vertical plane of two adjacent retaining wall modules 4 respectively, thereby realizing the connection of the upper and lower adjacent retaining wall modules 4.

[0055] like Figure 5As shown, support frames are welded to both the upper and lower ends of the steel plate 15. The roller 13 is mounted on the support frame via a rotating shaft and can roll up and down in the vertical direction. The roller 13 contacts the rear longitudinal beam 21 of the model box, which not only realizes the lateral support of the model box 1 for the retaining wall module 4, but also replaces the sliding friction of the direct contact between the retaining wall module 4 and the rear longitudinal beam 21 of the model box with the rolling friction between the roller 13 and the rear longitudinal beam 21 of the model box. This greatly reduces the loss of the downward force of the reinforcing bar 6 caused by friction and increases the accuracy of the test.

[0056] Multiple layers of reinforcing bars 6 are horizontally laid in the sand 5. One end of each reinforcing bar 6 is fixed to a steel hook 7, and the other end extends between the upper and lower wall modules 3, and is fixed by the friction between the wall modules 3 and the gravel 18. The hollowed-out area in the middle of the wall module 3 is filled with gravel 18, which provides friction to achieve a frictional connection between the reinforcing bars 6 and the wall module 3.

[0057] like Figure 6 As shown, the lengths of the retaining wall module 4 and the weighing platform 11 along the second horizontal direction (Y direction) are less than the length of the model box 1. Therefore, there is no contact between the retaining wall module 4 and the side wall 19 of the model box 1, nor between the weighing platform 11 and the side wall 19 of the model box, and no friction. Geotextile 17 covers the gaps between the retaining wall module 4 and the side wall 19 of the model box, as well as the gaps between the weighing platform 11 and the side wall 19 of the model box, effectively preventing sand 5 from leaking into the gaps.

[0058] A loading plate 9 is provided on the top surface of the uppermost layer of sand 5. The loading plate 9 is formed by splicing multiple rectangular concrete slabs. A jack 10 is fixed below the top crossbeam 20 of the model box. The other end of the jack 10 is in contact with the loading plate 9 and is used to apply a downward force. The top crossbeam 20 of the model box and the longitudinal beam 22 of the side wall of the model box can serve as a reaction frame for the jack 10 to transfer the force to the bottom plate of the model box.

[0059] The height of the weighing platform 11 can be selected as 200mm, and the width is the same as that of the bottom retaining wall module 4, which can be selected as 757mm.

[0060] The thickness of each concrete slab can be selected as 60mm, and the length and width can be selected as 500mm×400mm.

[0061] like Figure 3 As shown (where (a) is a top view and (b) is a vertical sectional view), the wall module 3 is a hollow structure that runs vertically through the wall. It is prefabricated using C30 concrete. The height of the wall module 3 in the vertical direction (Z direction) can be selected as 200mm, and the width in the first horizontal direction (X direction) can be selected as 300mm. The height of the hollowed-out area in the middle in the vertical direction can be selected as 200mm, and the width in the first horizontal direction can be selected as 200mm.

[0062] The foundation 2 is strip-shaped, extending along the second horizontal direction (Y direction), made of C30 precast concrete, and is a solid structure. Its height can be selected as 200mm, and its length along the second horizontal direction can be selected as 400mm.

[0063] The retaining wall module 4 is made of C30 precast concrete and is a solid structure. The height of the retaining wall module 4 can be selected as 800mm. The total height of the four retaining wall modules 4 after stacking is 3200mm. The top width of the uppermost retaining wall module 4 can be selected as 300mm, and the bottom width of the lowermost retaining wall module 4 can be selected as 757mm.

[0064] In this invention, the rolling friction of rollers replaces the sliding friction of the existing retaining wall directly against the model box, which greatly reduces the friction force to the point that it can be almost ignored.

[0065] Embodiments of the present invention also provide a method for testing the tensile strength of reinforcement in a reinforced soil retaining wall, using a device for testing the tensile strength of reinforcement in a reinforced soil retaining wall, the flowchart of which is shown below. Figure 7 As shown, the steps include:

[0066] S1. First, use a crane to place the weighing platform 11 inside the model box 1. Then, connect the first steel plate 15 with rollers 13 to the first retaining wall module 4. Then, hoist the first retaining wall module 4 with steel plate 15 and rollers 13 (i.e., the lowest existing retaining wall module) onto the weighing platform 11. When hoisting, make sure that the rollers 13 on the first steel plate 15 are in contact with the longitudinal beam 21 at the rear end of the model box.

[0067] S2, connect the second steel plate 15 equipped with rollers 13 to the second retaining wall module 4, and hoist the second retaining wall module 4 with steel plate 15 and rollers 13 onto the first retaining wall module 4. The rollers 13 contact the longitudinal beam 21 at the rear end of the model box. Then connect the steel plate 15 of the first retaining wall module 4 to the second retaining wall module 4, thereby connecting the first retaining wall module 4 and the second retaining wall module 4 through the steel plate 15. Figure 4 As shown.

[0068] S3, following steps S1-S2, install multiple retaining wall modules 4 and corresponding steel plates 15 sequentially until the design elevation is reached, thus connecting all retaining wall modules 4 into a single unit. Read and record the data using the load reading instrument 12; this data represents the overall mass M1 of the existing retaining wall modules 4. Then, cover the gaps between the retaining wall modules 4 and the model box sidewall 19, and between the weighing platform 11 and the model box sidewall 19, using geotextile 17. Figure 6 As shown, (a) is a schematic diagram of the first gap between the geotextile-covered retaining wall module and the side wall of the model box, and (b) is a schematic diagram of the second gap between the weighing platform and the side wall of the model box.

[0069] S4. Place the foundation 2 into the model box 1 near the front end, then place the wall module 3 on the foundation 2, and fill the hollowed-out area in the middle of the wall module 3 with gravel 18, making the gravel 18 flush with the upper surface of the wall module 3. Next, fill the space between the retaining wall module 4 and the wall module 3 with sand 5. When the sand 5 reaches the corresponding reinforcement layer 6 installation level, install the reinforcement layer 6, then place the next wall module 3, and continue filling with sand 5 above the installed reinforcement 6. Repeat this process until the designed height of the reinforced soil retaining wall is reached, and then read the mass M2 from the load reading instrument 12.

[0070] The reinforcement 6 is laid out as follows: First, the mesh of the reinforcement 6 is passed through the steel hooks 7 on the retaining wall module 4. Then, the other end of the reinforcement 6 is placed over the wall module 3 and tightened. Next, the wall module 3 above this layer of reinforcement 6 is placed. Gravel 18 is filled into the hollowed-out area in the middle of the upper wall module 3, and then the reinforcement 6 is loosened. Finally, sand 5 is filled on top of this layer of reinforcement 6. In actual engineering, during the laying process of the reinforcement 6 in the reinforced soil retaining wall, the connection points between the reinforcement 6 and the retaining wall module 4 and the wall module 3 should be kept taut. Otherwise, on the one hand, the wall module 3 will deform too much, and on the other hand, it will be difficult to achieve the connection function between the reinforcement 6 and the retaining wall module 4. Furthermore, if the reinforcement 6 is in a relaxed state during the filling of sand 5, the downward pull of the reinforcement on the retaining wall module 4 will be too small, and the test value will obviously not conform to actual engineering applications.

[0071] S5, load P is applied to sand 5 through jack 10 and loading plate 9, and the third mass M is read through load reading instrument 12. p ;

[0072] S6, based on the first mass M1, the second mass M2 and the third mass M p In addition to the dimensions and material properties of the reinforced soil retaining wall, calculate the downward force F (in N) of the reinforcement 6 per unit width on the retaining wall module 4. When the load is 0, the calculation method is as follows:

[0073] ;

[0074] Under load Under the action of the reinforcement bar 6, the formula for calculating the tensile force (in N) F per unit width (1m) is as follows:

[0075] ;

[0076] In the formula, The readings are from the load reading instrument under the self-weight of sand 5, in kg. For load The reading of the load reading instrument under action, in kg; The total mass of retaining wall module 4 is expressed in kg. The density of sand 5 is expressed in kg / m³. 3 ; The height from the upper surface of the weighing platform 11 to the top surface of the sand 5 is in meters. The difference between the bottom width and the top width of the multiple retaining wall modules 4 along the first horizontal direction is expressed in meters. The load applied to jack 10, in N; The length of the retaining wall module 4 along the second horizontal direction, which is perpendicular to the first horizontal direction, is in meters. Represents gravitational acceleration, unit .

[0077] In this invention, M2×g is the gravity converted from the mass (in kg) obtained by the weighing platform 11 under the self-weight of the sand 5; The total weight of the retaining wall module 4; above the weighing platform 11, in addition to the retaining wall module 4, there is also a triangular section of sand 5 perpendicular to the second horizontal direction. The weight of the sand 5 above the weighing platform 11; The width of the second horizontal direction is The downward force generated by the self-weight of the sand 5 is converted into the downward force per unit width. In this invention, the shear stress at the interface between the sand 5 above the weighing platform 11 and the sand 5 above the non-weighing platform 11 is extremely small and can be ignored.

[0078] The tensile force obtained by this invention can provide clear evidence for the strain concentration phenomenon at the connection between the reinforcement and the existing retaining wall, promoting the innovation of reinforcement strength design methods. Moreover, the total tensile force obtained by the test can be used as a precise additional load to be input into the stability calculation of the existing retaining wall foundation, and used to evaluate the bearing capacity stability and deformation of the foundation below the existing retaining wall. In addition, this testing device is an indoor full-scale testing device, and the test data obtained is true and reliable, providing true and reliable design parameters for projects with similar structural forms.

[0079] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0080] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A method for testing the tensile strength of reinforcing bars in a reinforced soil retaining wall, characterized by the following steps: include: S1, first use a crane to place the weighing platform (11) inside the model box (1), then connect the first steel plate (15) with rollers (13) to the first retaining wall module (4), and hoist the first retaining wall module (4) with steel plate (15) and rollers (13) onto the weighing platform (11); S2, connect the second steel plate (15) equipped with roller (13) to the second retaining wall module (4), and hoist the second retaining wall module (4) with steel plate (15) and roller (13) onto the first retaining wall module (4). The roller (13) contacts the longitudinal beam (21) at the rear end of the model box. Then connect the steel plate (15) of the first retaining wall module (4) to the second retaining wall module (4), so that the first retaining wall module (4) and the second retaining wall module (4) are connected through the steel plate (15). S3. According to the method of steps S1~S2, install multiple retaining wall modules (4) and corresponding steel plates (15) in sequence until the design elevation is reached, so that all retaining wall modules (4) are connected into a whole. Read and record the data through the load reading instrument (12). At this time, the data is the overall mass M1 of the existing retaining wall module (4). Use geotextile (17) to cover the gap between the retaining wall module (4) and the side wall (19) of the model box, and between the weighing platform (11) and the side wall (19) of the model box. S4, place the foundation (2) into the model box (1) near the front end, then place the wall module (3) on the foundation (2), and fill the hollowed-out area in the middle of the wall module (3) with gravel (18). Then fill the sand (5) between the retaining wall module (4) and the wall module (3). When the sand (5) is filled to the corresponding layer of reinforcement (6) at the elevation, lay the reinforcement (6) of that layer. Then place the next wall module (3), and continue to fill the sand (5) above the laid reinforcement (6). Repeat this process until the design height of the reinforced soil retaining wall is reached, and read the mass M2 on the load reading instrument (12). S5, load is applied to the sand (5) by jack (10) and loading plate (9). The third mass M is read by the load reading instrument (12). p ; S6, based on the first mass M1, the second mass M2 and the third mass M p In addition to the dimensions and material properties of the reinforced soil retaining wall, the tensile force of the reinforcement (6) per unit width on the retaining wall module (4) is calculated. When the load is 0, the calculation method is as follows: ； Under load Under the action, the downward force of the reinforcing bar (6) per unit width F The calculation formula is: ； In the formula, The readings are from the load reading instrument under the self-weight of the sand. For load Load reading under load For the overall quality of the retaining wall module, The density of sandy soil, The height from the top surface of the weighing platform to the top surface of the sand. The difference between the bottom width and the top width of multiple retaining wall modules along the first horizontal direction. It is the acceleration due to gravity. The load applied to the jack The length of the retaining wall module along the second horizontal direction, which is perpendicular to the first horizontal direction.

2. The method for testing the tensile strength of reinforcement in a reinforced soil retaining wall according to claim 1, characterized in that, The tensile testing device for reinforced soil retaining wall is used. The weighing platform (11) mentioned in S1 is set at the bottom of the model box (1) near the rear end. The longitudinal section of the retaining wall module (4) is a right trapezoidal structure. A steel hook (7) is set on its inclined surface, and its vertical surface is used to fix the steel plate (15). Support frames are set at both the upper and lower ends of the steel plate (15), and the roller (13) is installed on the support frame through the rotating shaft.

3. The method for testing the tensile strength of reinforcement in a reinforced soil retaining wall according to claim 1, characterized in that, The front end, rear end and top of the model box (1) are open. The rear end is provided with a rear longitudinal beam (21) and a cross beam, and the top is provided with a top cross beam (20). The side walls (19) on both sides of the model box (1) are closed surfaces, and the side walls (19) are provided with a side longitudinal beam (22). The rear longitudinal beam (21) and the side longitudinal beam (22) are both perpendicular to the ground.

4. The method for testing the tensile strength of reinforcement in a reinforced soil retaining wall according to claim 1, characterized in that, After the wall module (3) described in S4 is stacked to the design elevation, a loading plate (9) is set on the top surface of the uppermost layer of sand (5). The loading plate (9) is formed by splicing multiple rectangular concrete slabs. A jack (10) is fixed below the top beam (20) of the model box. The other end of the jack (10) is in contact with the loading plate (9).

5. The method for testing the tensile strength of reinforcement in a reinforced soil retaining wall according to claim 1, characterized in that, The steel plate (15) is provided with two rows of bolt holes (16). The bolts (8) pass through the upper and lower rows of bolt holes (16) of the steel plate (15) respectively, and the nuts (14) are tightened to fix the upper and lower ends of the steel plate (15) to the lower and upper sides of the vertical plane of the two adjacent retaining wall modules (4) respectively.

6. The method for testing the tensile strength of reinforcement in a reinforced soil retaining wall according to claim 1, characterized in that, The wall module (3) is a hollow structure that runs vertically through the wall.

7. The method for testing the tensile strength of reinforcement in a reinforced soil retaining wall according to claim 1, characterized in that, One end of the reinforcing bar (6) is fixed to the reinforcing bar hook (7), and the other end extends between the upper and lower wall modules (3) and is fixed by the friction between the wall module (3) and the gravel (18).

8. The method for testing the tensile strength of reinforcement in a reinforced soil retaining wall according to claim 1, characterized in that, The weighing platform (11) is equipped with a load sensor, and the load reading instrument (12) is connected to the load sensor.

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