A vibration table experimental model box and a model box assembly method

Abstract

The present application relates to the technical fields of geotechnical engineering, and discloses a shaking table experiment model box and a model box assembly method, which comprises a bottom frame, a plurality of shear frames, a top block, a truss and a prestressed tendon. The bottom frame is arranged on a shaking table, and the surface of the bottom frame is provided with a plurality of shear frames in a stacked manner. The plurality of shear frames enclose an accommodating cavity with an opening facing upward, which is used for placing experimental samples. The long side of the shear frame is provided with a truss, and the truss is provided with a prestressed tendon. By arranging the truss on the long side of the shear frame, the side wall of the shear frame can be effectively reinforced, thereby avoiding the deformation of the shear frame. Meanwhile, the prestressed tendon is arranged on the truss to apply prestress to the truss, further improving the stability of the shear frame.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, specifically to a shaking table test model box and a method for assembling the model box. Background Technology

[0002] In geotechnical shaking table tests, the test soil box is used to hold the model soil. After the model soil is filled, the lateral earth pressure generated by the soil will compress the model box. When the amount of soil is large, it will cause severe flexural deformation of the model box, which will cause the soil to expand and deform towards the surrounding boundaries. In order to better simulate the shear deformation of the original soil under seismic loading and reduce the "model box effect", the model soil box is usually designed as a layered structure that can undergo shear deformation.

[0003] Currently, existing layered shear soil boxes in China typically use ball bearings between adjacent frames to allow for independent movement of different frame layers, thus enabling longitudinal and lateral movement between adjacent frames. However, in experiments, there is no limit to the length of the frames. In experiments with longer model boxes, the experimental soil will be squeezed against the long sidewalls of the frames during filling, and the sidewalls of longer frames or model boxes will deform, leading to cracking after the soil and sidewalls deform together, thus affecting the experiment.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a shaking table test model box and a method for assembling the model box, which aims to solve the problem that the frame is easily deformed by compression when the test soil is filled, resulting in soil cracking and affecting the experiment.

[0006] The technical solution adopted by this invention to solve the technical problem is as follows:

[0007] A shaking table test model box, comprising:

[0008] Bottom frame;

[0009] Multiple shearing frames are stacked on the bottom frame; the multiple shearing frames cooperate to form an upward-facing receiving cavity, which is used to place experimental samples.

[0010] A top block, disposed on the shear frame, is used for rolling action in any direction between two adjacent shear frames;

[0011] A truss is installed on the long side of the shear frame to reinforce the sidewalls of the shear frame.

[0012] Prestressing tendons; the two ends of the prestressing tendons are respectively disposed on the two short sides of the shear frame, and the prestressing tendons cooperate with the truss to apply prestress to the truss.

[0013] Furthermore, the truss is provided with guide rail assemblies, and the guide rail assemblies of two adjacent trusses cooperate to allow the two adjacent shear frames to slide against each other.

[0014] Furthermore, the guide rail assembly includes:

[0015] The first guide rail is installed on the top wall of the truss;

[0016] The second guide rail is disposed on the bottom wall of the truss; the slider of the first guide rail is connected to the slider of the second guide rail; the slider of the first guide rail of the truss is connected to the slider of the second guide rail of the adjacent truss.

[0017] Furthermore, the truss includes:

[0018] Multiple support rods are provided on the long side of the shear frame; the length of the multiple support rods gradually decreases from the midpoint of the shear frame towards both sides.

[0019] Furthermore, one end of the prestressing tendon is fixedly disposed on the first short side of the shear frame, and the other end is disposed on the second short side of the shear frame through a snap-fit ​​assembly. The prestress applied by the prestressing tendon to the support rod can be adjusted through the snap-fit ​​assembly.

[0020] Furthermore, the surface of the shear frame is provided with a plurality of upward-facing recessed grooves, the recessed grooves corresponding to the bottom wall of the upper layer of the shear frame, and an adjustment component is provided inside the recessed groove. The adjustment component cooperates with the top block so that the top block extends upward out of the recessed groove and abuts against the shear frame.

[0021] Furthermore, the adjusting component is any one of a spring, a hydraulic telescopic rod, and an inflatable airbag.

[0022] Furthermore, the top block is a bullseye bearing, and the side wall of the bullseye bearing is provided with rollers, which abut against the side wall of the settling trough.

[0023] Furthermore, it also includes:

[0024] Multiple lifting bases are disposed on the surface of the vibration table;

[0025] A bottom reinforcement layer is disposed on the surface of the plurality of lifting bases; the shear frame is located on the bottom reinforcement layer, and a reinforcing rib is provided between the bottom reinforcement layer and the lifting base.

[0026] An assembly method for a model box, based on the above-mentioned shaking table test model box, includes:

[0027] Multiple shear frames are stacked on the bottom frame and aligned to form the receiving cavity;

[0028] The plastic film is placed concavely into the receiving cavity;

[0029] The experimental soil was placed inside the plastic film and moistened.

[0030] Adjust the prestressing tendons to keep the sidewalls of the shear frame straight, and start the vibration table to conduct the experiment.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] In this invention, a bottom frame is set on a vibration table, and multiple shear frames are stacked on the surface of the bottom frame. The multiple shear frames enclose an upward-facing receiving cavity for placing experimental samples. A truss is set on the long side of the shear frame, and prestressing tendons are set on the truss. By setting a truss on the long side of the shear frame, the side wall of the shear frame can be effectively reinforced, thereby avoiding deformation of the shear frame. At the same time, the prestressing tendons on the truss can apply prestress to the truss, further improving the stability of the shear frame. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0034] Figure 2 This is a schematic diagram of the bullseye bearing structure of the present invention.

[0035] Figure 3 for Figure 2 Enlarged diagram of point A in the middle.

[0036] Figure 4 This is a top view of the model box structure of the present invention.

[0037] Figure 5 This is a schematic diagram of the shear frame structure of the present invention.

[0038] Figure 6 This is a schematic diagram of two adjacent shear frame structures of the present invention.

[0039] Figure 7 This is a flowchart of the vibration table test method of the present invention.

[0040] The numbers in the diagram represent: 1. Bottom frame; 11. Lifting base; 12. Bottom reinforcement layer; 2. Shear frame; 21. Sinking trough; 3. Enclosure panel; 4. Top block; 41. Roller; 5. Adjustment assembly; 6. Truss; 61. Support rod; 62. First guide rail; 63. Second guide rail; 7. Prestressed tendon. Detailed Implementation

[0041] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] In view of the shortcomings of the prior art, this embodiment provides a shaking table experimental model box and an assembly method for the model box, which can be referred to as follows:

[0045] As attached Figure 1 and attached Figure 2As shown, a shaking table experimental model box includes a bottom frame 1, multiple shear frames 2, a top block 4, a truss 6, and prestressing tendons 7. The bottom frame 1 is set on the shaking table, and multiple shear frames 2 are stacked on the surface of the bottom frame 1. The multiple shear frames 2 enclose an upward-facing receiving cavity for placing experimental samples. The top block 4 is set on the shear frame 2, and the top block 4 abuts against the shear frame 2 above it, allowing adjacent shear frames 2 to roll in any direction. The truss 6 is set on the long side of the shear frame 2 to reinforce the long side of the shear frame 2. The two ends of the prestressing tendon 7 are respectively set on the two short sides of the shear frame 2, and the prestressing tendon 7 cooperates with the side walls of multiple support rods 61 to apply prestress to the multiple support rods 61.

[0046] The bottom frame 1 refers to the basic steel structure that supports the shear layer. It can be constructed using welded truss beams to provide stable support for the upper structure. The lifting base 11 is fixed to the vibration table. Through diagonal bracing and the bottom reinforcement layer 12, a larger model box size can be obtained, enabling larger-scale vibration experiments on a limited platform. The shear frame 2 refers to rigid frame units arranged in layers, such as rectangular frames formed by splicing channel steel. The combination of each layer of frames constitutes the receiving chamber.

[0047] Prestressing tendons 7 refer to flexible components with pre-tensioned stress, which can be implemented using steel strands or high-strength steel wire ropes. Both ends are fixed to the short sidewall of the shear layer using anchors. Support members 61 refer to supporting components distributed along the long side of the shear layer, which can be implemented using channel steel or I-beams. Support members 61 are arranged symmetrically to form a truss structure 6, and prestressing tendons 7 are arranged along the sidewall of support members 61.

[0048] Specifically, the prestressing force of the prestressing tendon 7 is applied to the truss 6 structure and then to the side wall of the shear frame 2. Multiple shear frames 2 are stacked, and adjacent shear frames 2 are in contact through the top block 4 so that adjacent shear frames 2 can roll in any direction. Experimental soil is placed into the cavity and moistened. Then, the prestress on the truss 6 can be adjusted by the prestressing tendon 7 to ensure the straightness of the long side wall of the shear frame 2, which is convenient for simulation experiments.

[0049] Compared with existing technologies, traditional layered shear soil boxes rely on the stiffness of the shear frame 2 itself to resist deformation, which is prone to bending instability in long-span structures. This application establishes a reverse stress field to balance the lateral force after the soil load is applied through the truss 6 and the prestressed active reinforcement mechanism, and strictly controls the flatness of the shear frame.

[0050] Through the above technical solutions, this application effectively suppresses the bending deformation of the long-span shear frame 2 under soil pressure, maintaining the stability of the shear frame 2. The prestressing constraint of the prestressed tendons 7 prevents the overall instability of the shear frame 2. The active reinforcement mechanism of the prestressed tendons 7 ensures the stability of the shear frame 2 during the initial preparation, ensuring that the soil shear deformation is consistent with the actual seismic response, and improving the reliability of experimental data.

[0051] In this embodiment, the top of the topmost shear frame 2 is provided with a surrounding plate 3. The surrounding plate 3 is ring-shaped and matches the opening of the receiving cavity to increase the depth of the receiving cavity; at the same time, it avoids splashing of experimental soil or water when wetting the experimental soil and during the experiment.

[0052] This application further proposes that the truss 6 is provided with a guide rail assembly, and the guide rail assemblies of two adjacent trusses 6 cooperate to allow two adjacent shear frames 2 to slide against each other.

[0053] Truss 6 bears most of the vertical load of the model box, while top block 4 bears a smaller portion. Truss 6 refers to a supporting structure composed of multiple struts 61, which can be a long strip structure. The guide rail assembly refers to a sliding guide structure composed of a first guide rail 62 and a second guide rail 63. Specifically, it can be achieved by connecting the first guide rail 62 on the top wall and the second guide rail 63 on the bottom wall through sliders. The guide rail assemblies of adjacent trusses 6 are cross-connected through sliders.

[0054] Specifically, the first guide rail 62 slider in the guide rail assembly forms a cross connection with the second guide rail 63 slider of the adjacent truss 6. When the vibration load is transmitted to the shear layer, the guide rail assembly guides the adjacent layer to make relative displacement along the preset sliding trajectory. The two guide rails can deform in coordination, thereby realizing shear deformation in any direction in the horizontal plane. The linkage between the adjacent sliders maintains the flatness of the contact surface of the shear frame 2.

[0055] Compared to existing technologies, traditional layered shear boxes rely solely on ball bearings to move adjacent shear frames 2. However, excessive force on the ball bearings can cause damage. Furthermore, the ball bearing design limits the movement distance between shear layers. When the edge of a shear layer moves past the ball bearings, that layer experiences no vertical force and directly presses onto the next shear layer. This solution enhances the bending resistance of the shear frame 2 through a truss structure 6, maintaining its flatness under soil pressure. Simultaneously, the combination of two guide rail assemblies allows for sliding in any direction within the horizontal plane, and the length of the guide rails provides limiting protection, preventing adjacent shear layers from slipping out.

[0056] Furthermore, the interaction of the guide rail assemblies between two adjacent trusses 6 can also be used to bear the vertical force of the shear layer.

[0057] Through the above technical solution, the sliding trajectory between adjacent shear layers is precisely defined by the guide rail assembly, and the two adjacent trusses 6 always remain in close contact during vibration. The uniformity of the contact stress distribution between the ball and the shear frame 2 is improved and dispersed, and the boundary constraint conditions of the soil during the experiment are closer to the free field state.

[0058] In this embodiment, the top block 4 is disposed on the short side of the shear frame 2, and the truss 6 is disposed on the long side of the shear frame 2; I-beams are disposed on the short plate of the shear frame 2 for reinforcement.

[0059] As attached Figure 5 As shown, this application further proposes a guide rail assembly including a first guide rail 62 and a second guide rail 63. The first guide rail 62 is disposed on the top wall of the truss 6, and the second guide rail 63 is disposed on the bottom wall of the truss 6. The sliders of the first guide rail 62 of two adjacent trusses 6 are connected to the sliders of the second guide rail 63.

[0060] The first guide rail 62 refers to a linear sliding component installed on the top bearing surface of the truss 6. Specifically, it can be implemented using a T-slot guide rail in conjunction with a ball bearing slider, used to guide the shear frame 2 to move horizontally. The second guide rail 62 refers to a linear sliding component installed on the bottom bearing surface of the truss 6, installed in the same manner as the first guide rail 62, used to form a linkage constraint with the second guide rail 63 of the adjacent truss 6. The slider connection between the first guide rail 62 and the second guide rail 63 refers to fixing the sliders of both through rigid connecting rods or connecting plates, such as using bolts to connect steel plates to achieve linkage, so that the upper and lower guide rails form a synchronous sliding mechanism. The cross-layer connection of the guide rail sliders between trusses 6 refers to connecting the slider of the first guide rail 62 at the top of the current truss 6 with the slider of the second guide rail 63 at the bottom of the adjacent truss 6 through a hinged pin, such as using a universal joint connector to achieve multi-directional freedom constraints.

[0061] Specifically, when the shear frame 2 moves, the upper truss 6 can slide along the longitudinal or transverse direction of the shear frame 2 under the action of the first guide rail 62 and the second guide rail 63. Adjacent trusses 6 form a linkage system through cross-layer connecting sliders. During transverse displacement, the universal joint connector allows adjacent shear frames 2 to slide relative to each other in the XY plane, thereby achieving shear deformation in any direction within the plane.

[0062] Compared with existing technologies, traditional single-layer ball bearings are prone to detachment from the shear frame 2 in long-span frames, leading to overload of the remaining ball bearings and failure to guide the movement of the shear frame 2. This solution forms a bidirectional constraint through the linkage of upper and lower guide rails, decomposing the deformation of the shear frame 2 into synchronous displacements of the upper and lower layers, avoiding stress concentration at a single support point. At the same time, through the action of the first guide rail 62 and the second guide rail 63, large-scale free sliding of the truss 6 in the XY plane can be achieved.

[0063] Through the above technical solution, this application effectively solves the problem of poor contact when the long model box frame slides, ensuring that frames of different lengths maintain planar contact during movement. The linkage constraint of the upper and lower guide rails reduces the force on the bullseye bearing and improves the service life of the bullseye bearing. At the same time, through the action of the first guide rail 62 and the second guide rail 63, the shear frame 2 can slide arbitrarily in the XY plane.

[0064] As attached Figure 5 As shown, this application further proposes a truss 6 structure for a shaking table experimental model box, which includes multiple support rods 61 arranged on the long side of the shear frame 2.

[0065] Furthermore, the bending moment on the long side of the shear frame 2 is larger in the middle and decreases from the middle to both sides. In order to reduce the overall weight of the model box and make reasonable use of steel, the length of the support rod 61 is gradually shortened from the midpoint of the shear frame 2 to both sides.

[0066] The multiple support rods 61 can be arranged in an alternating manner to improve the support for the side wall of the shear frame 2; at the same time, the arrangement of the multiple support rods 61 also facilitates the installation of the first guide rail 62 and the second guide rail 63, providing convenience for the movement of the shear frame 2.

[0067] Because the length of the support rod 61 gradually shortens from the middle of the side wall of the shear frame 2 towards both sides, the prestressing tendons 7 are arranged in an arc shape along the outer wall of the multiple support rods 61, with the middle position of the side wall of the shear frame 2 being the highest point. When soil pressure acts on the shear frame, the force on the support rod 61 cancels out the torque generated by the prestressing, thereby suppressing the deformation of the long side wall of the shear frame 2. At the same time, the continuous tensioning of the prestressing tendons 7 forms a cooperative force-bearing system among the multiple support rods 61.

[0068] Furthermore, the support rod 61 can also be a semi-circular arc rod, with both ends of the arc rod set on the side wall of the shear frame 2, and multiple arc rods arranged in an array along the length direction of the side wall of the shear frame 2, and multiple arc rods can be in an interlaced state. Through the arc rods and the interlacing of the arc rods, the deformation of the shear frame 2 under the action of the lateral force of the soil layer can be effectively avoided.

[0069] As attached Figure 5 and attached Figure 6 As shown, in this embodiment, the sidewall of the shear frame 2 is provided with multiple trusses 6, which are arranged in an array to make the sidewall of the shear frame 2 more stable.

[0070] As attached Figure 4 and attached Figure 5As shown, this application further proposes that one end of the prestressing tendon 7 is fixedly set on the first short side of the shear frame 2, and the other end is set on the second short side of the shear frame 2 through a snap-fit ​​assembly. The prestress applied to the support rod 61 by the prestressing tendon 7 can be adjusted through the snap-fit ​​assembly.

[0071] The prestressing tendon 7 refers to a high-strength material component used to apply tensile force. Specifically, it can be made of steel strand or carbon fiber bundle. Through tension, it generates a reverse restraint force on the support rod 61 to counteract the lateral pressure of the soil. The clip assembly refers to an adjustable fastening device. Specifically, it can be implemented using a threaded locking mechanism or a ratchet clamp, or through the adjustment method of a belt in existing technology. By changing the fastening position of the clip, the effective length of the prestressing tendon 7 is adjusted, thereby controlling the magnitude of the prestress applied to the support rod 61.

[0072] Specifically, one end of the prestressing tendon 7 is fixed to the first short side to form an anchorage foundation, and the other end is arranged on the side wall of the support rod 61 and connected to the snap-fit ​​assembly on the second short side. When the shear frame 2 of the model box deforms due to excessive length or soil pressure, the operator can shorten the effective length of the prestressing tendon 7 by adjusting the locking position of the snap-fit ​​assembly, thereby increasing the compressive force on the support rod 61 and allowing the shear frame 2 to return to a straight state under prestress. This dynamic adjustment mechanism ensures that the shear frame 2 maintains a uniformly distributed prestress throughout the experiment, thus resisting bending deformation. After the experimental backfilling is completed, the lower layer of shear frame 2 experiences greater stress than the upper layer. The prestress of each layer can be adjusted according to the stress of the shear frame 2 to strictly control the flatness of each layer of shear frame 2.

[0073] Through the above technical solution, this application solves the problem of bending deformation of the side wall of the shear frame 2 of the model box due to excessive length. At the same time, the prestress adjustment operation is simplified by the tightness adjustment function of the buckle assembly, ensuring that the side wall of the shear frame 2 remains straight throughout the experiment, effectively improving the reliability of the vibration table experimental data.

[0074] As attached Figure 5 and attached Figure 6 As shown, this application further proposes that the surface of the shear frame 2 is provided with a plurality of upward-facing recesses 21, the recesses 21 corresponding to the bottom wall of the upper layer of the shear frame 2; a top block 4 is vertically slidably arranged in the recesses 21, and an adjustment component 5 is also provided in the recesses 21. By adjusting the component 5, the top block 4 can be driven to extend upward out of the recesses 21 and abut against the bottom of the shear frame 2.

[0075] The recess 21 refers to a square groove machined onto the surface of the frame. The top block 4 is a bullseye bearing, which is a spherical rolling component with multi-directional rolling function, such as a spherical bearing with an internal ball cage, and can rotate freely within the recess 21. The adjusting component 5 refers to the actuator that controls the lifting and lowering of the bearing, such as a sleeve structure with a built-in spring, which adjusts the bearing support height by preloading the spring.

[0076] Specifically, the bottom frame 1 establishes a stable support platform, and multiple stacked shear frames 2 slide between layers via top blocks 4 within the recess 21. During installation, the bottom of the frame is tilted, and the adjusting component 5 pushes the bearing to move vertically along the recess 21, compensating for the contact surface gap caused by the deformation of the shear frames 2. The top blocks 4 within the recess 21 not only allow the shear frames 2 to move but also adjust their height to maintain uniform contact pressure. The enclosure plate 3 seals the top of the receiving cavity, forming a complete experimental space. Each layer of shear frames 2 forms a dynamic support system through adjustable bearings, and bullseye bushings provide support force during vibration to achieve the experimental purpose.

[0077] Compared to existing technologies, traditional solutions using fixed-height ball bearing supports cannot accommodate uneven contact surfaces caused by frame deformation. This solution utilizes a height-adjustable top block 4 in conjunction with an adjustment component 5 to adjust the support point height in real time, eliminating gaps caused by the bending of the shear frame 2. This dynamic adjustment mechanism effectively solves the stress concentration problem caused by the deformation of the long shear frame 2.

[0078] Through the above technical solution, this application achieves dynamic compensation of the interlayer support height, ensuring uniform stress on the contact surfaces of the shear frames 2 in each layer. The top block 4 maintains effective contact under the action of the adjusting component 5, preventing support failure due to deformation of the shear frame 2. The sinkhole 21 also restricts the bearing movement direction, preventing unexpected displacement from interfering with experimental data. This design significantly improves the structural stability of the long-size model box, providing a reliable guarantee for accurately simulating soil shear deformation.

[0079] As attached Figure 3 As shown, this application further proposes that the adjustment component 5 is any one of a spring, a hydraulic telescopic rod, and an inflatable airbag.

[0080] A spring is an elastic element that deforms elastically when subjected to external force and returns to its original shape after the force is removed. It can be implemented using helical springs or disc springs, and its elastic modulus can be selected based on the actual support requirements using different materials or structural forms. A hydraulic telescopic rod is a rod-shaped component that achieves telescopic movement through hydraulic drive. It can be implemented using single-acting or double-acting hydraulic cylinders, and the hydraulic system pressure can be adjusted to control the support force. An inflatable airbag is a sealed cavity made of flexible material that expands by being filled with compressed gas. It can be made of rubber or polyurethane, and the internal air pressure can be adjusted using an external air pump.

[0081] Specifically, when the model box frame experiences localized bending along its length, the spring automatically adjusts the vertical support force through elastic deformation, ensuring that the top block 4 remains in contact with the upper shear frame 2. The hydraulic telescopic rod can precisely adjust its lifting stroke through an external hydraulic control system, compensating for the deformation of the shear frame 2 in real time. The inflatable airbag adjusts its expansion height by changing its internal air pressure, flexibly adapting to the bending deformation of the shear frame 2. During the experiment, the adjustment component 5 dynamically adjusts the vertical position of the top block 4 according to the displacement changes of the shear frame 2, ensuring a uniform pressure distribution on the shear frame 2 and preventing the top block from detaching from contact or stress concentration due to localized deformation of the shear frame 2.

[0082] Through the above technical solution, this application solves the problem of poor ball contact caused by the deformation of the long shear frame 2. By dynamically adjusting the support force, stable contact between the shear frames 2 is maintained, while the local effect of soil pressure on the shear frame 2 structure is dispersed, preventing irreversible bending deformation of the shear frame 2 and ensuring the accuracy of soil boundary conditions during the experiment. At the same time, this application provides a variety of dynamic adjustment methods, which can be selected according to experimental requirements.

[0083] Furthermore, a sensor can be installed at the bottom of the hydraulic telescopic rod or airbag. The force exerted on the top block 4 is applied to the sensor through the hydraulic telescopic rod or airbag, and the shear force borne by the top block 4 can be clearly detected. Based on the value detected by the sensor, the height of the top block 4 extending out of the sink 21 can be adjusted so that the shear force borne by each top block 4 is the same.

[0084] As attached Figure 3 As shown, this application further proposes that the top block 4 is a bullseye bearing, and the side wall of the bullseye bearing is provided with a roller 41, which abuts against the side wall of the settling trough 21.

[0085] Roller 41 refers to a cylindrical or spherical rolling element with a rotation axis, specifically a metal wheel with ball bearings, which transmits lateral loads through rolling contact. The sidewalls of the groove 21 refer to the vertical surfaces on both sides of the groove 21 formed on the surface of the model box shear frame 2. These can be constructed of hardened metal plates or polymer materials, with surfaces machined into smooth planes or curved surfaces to constrain the movement trajectory of the roller 41.

[0086] Specifically, when the vibration table generates lateral shear force, the bullseye bearing tends to displace within the groove 21. At this time, the roller 41 forms rolling contact with the sidewall of the groove 21, converting the sliding friction between the bullseye bearing sidewall and the groove 21 sidewall into rolling friction. The roller 41 absorbs the displacement energy through its own rotational motion, preventing direct contact between the bullseye bearing body and the groove 21 sidewall. This structure maintains the load-bearing capacity of the bullseye bearing while reducing the coefficient of friction of the contact surface through the rolling support structure, enabling the bullseye bearing to move without obstruction during shear deformation and ensuring the independent movement accuracy of the interlayer frame.

[0087] Through the above technical solution, this application transforms the sliding process of the bullseye bearing within the settling groove 21 into a rolling motion mode, significantly reducing the frictional resistance of the contact surface and avoiding localized stress concentration caused by sliding friction. This structure ensures smooth relative movement of each layer of shear frame 2 during the shaking table experiment, preventing the deformation of the shear frame 2 from interfering with the boundary conditions of the experimental soil, thereby improving the accuracy of seismic wave propagation simulation.

[0088] As attached Figure 1 As shown, this application further proposes a plurality of lifting bases 11 disposed on the surface of the vibration table; a bottom reinforcement layer 12 disposed on the surface of the plurality of lifting bases 11; a shear frame 2 located on the bottom reinforcement layer 12, and a reinforcing rib disposed between the bottom reinforcement layer 12 and the lifting bases 11.

[0089] The lifting base 11 refers to a distributed support structure set on the surface of the vibration table, which can be made of metal. It is used to lift the bearing surface of the vibration table to a set height and provide multi-point support for the bottom reinforcement layer 12. The bottom reinforcement layer 12 refers to a rigid bearing layer covering the surface of the lifting base 11, which can be made of welded steel plates. It is used to support the shear frame 2 and maintain the flatness of its mounting surface. The reinforcing ribs are anti-deformation components connecting the lifting base 11 and the bottom reinforcement layer 12. They can be made of angle steel, I-beams, or steel strips welded together to form a grid structure, which is used to resist the shear force and bending stress generated during vibration.

[0090] Specifically, the lifting bases 11 are spaced apart on the surface of the vibration table, forming multiple independent support points, which reduces local stress concentration by dispersing the vibration transmission path. The bottom reinforcement layer 12 covers all the lifting bases 11 to form a continuous rigid surface, eliminating the tilting of the shear frame 2 caused by the unevenness of the vibration table surface. Reinforcing ribs construct triangular or cross-bracing structures at the connection between the lifting bases 11 and the bottom reinforcement layer 12, which increase the bending stiffness of the contact surface to suppress vibration-induced deformation, while also constraining the horizontal displacement of the lifting bases 11, ensuring the geometric stability of the bottom reinforcement layer 12 under dynamic loads.

[0091] Through the above technical solution, this application can solve the problem of frame bending caused by insufficient stiffness of the bottom support structure of the model box during vibration. By combining multi-point distributed support with a rigid bearing layer, the flatness of the installation plane of the shear frame 2 is maintained, avoiding stress concentration caused by shear layer misalignment. The cross-support structure of the reinforcing ribs suppresses dynamic deformation during vibration transmission, ensuring the consistency of soil boundary conditions during the experiment, thereby improving the accuracy of shaking table experimental data.

[0092] The lifting base 11 can also expand the area of ​​the model box. The lifting base 11 is connected to the vibration table surface by bolts to enable the vibration table model box to be cantilevered, so that it exceeds the size range of the vibration table.

[0093] In this embodiment, the bottom shear frame 2 is welded to the bottom frame 1 to ensure its stability; only the first guide rail 62 is provided on the truss 6 of the bottom shear frame 2.

[0094] As attached Figure 7 As shown, this application also proposes an assembly method for a model box, based on the above-mentioned shaking table experimental model box, including the following steps:

[0095] S100, multiple shear frames are stacked on the bottom frame and aligned to form the receiving cavity.

[0096] The vibration table is equipped with a lifting base 11 and a bottom reinforcement layer 12. Multiple shear frames 2 are stacked on the bottom frame 1 to form a receiving cavity. Then, the protrusion height of each bullseye bearing is adjusted by the adjustment component 5 so that each bullseye bearing bears the same shear force.

[0097] After the shear frame 2 is set up, the enclosure 3 can be placed on top of the shear frame 2 and fixed by welding to increase the depth of the containment cavity and prevent experimental soil or water from splashing out of the containment cavity.

[0098] S200, the plastic film is placed concavely into the receiving cavity;

[0099] Multiple stacked shear frames 2, together with a bottom reinforcing layer 12, form an upward-facing receiving cavity. Then, a plastic film is placed concavely into the receiving cavity to cover the gap between adjacent shear frames 2, facilitating the placement of experimental soil.

[0100] The plastic film can wrap the experimental soil, preventing the soil from directly contacting the shear layer. It can also form a closed groove with an opening at the top to prevent water from seeping into the experimental soil, while simulating the free deformation state under infinite boundary conditions.

[0101] S300, the experimental soil is placed inside the plastic film and moistened;

[0102] The experimental soil was placed inside a plastic film and leveled. Then water was injected into the experimental soil to moisten it and meet the experimental requirements.

[0103] Among them, wetting the experimental soil refers to adding water to the soil placed in the film, which can be achieved by spraying or soaking, so that the soil moisture is close to the actual working conditions, ensuring the authenticity of the shear deformation response.

[0104] S400, adjust the prestressed tendons to keep the sidewalls of the shear frame straight, and start the vibration table to conduct the experiment.

[0105] When the experimental soil is filled and water is injected, it will cause more compressive force on the side wall of the shear frame 2, which will cause the side wall of the shear frame 2 to bend. At this time, the length of the prestressing tendon 7 can be adjusted to adjust the prestress of the truss 6 on the side wall of the shear frame 2, so that the shear frame 2 can maintain its initial square structure and the side wall of the shear frame 2 can be kept straight, and then the experiment can be carried out.

[0106] Specifically, in the shaking table experiment, the vertical position of all bullseye bearings was matched with the shear force distribution in their respective areas by adjusting component 5, eliminating stress concentration caused by poor contact. A plastic film forms a flexible wrapping layer within the containment cavity, isolating the soil from direct friction with the shear layer and simulating the unconstrained state of the soil by an infinite field boundary through the film's own extensibility. The shear wave propagation characteristics generated by the wetted soil during vibration are closer to the actual foundation response. The prestressed tendons 7, through the preload applied to the short sides at both ends, balance the bending moment of the lateral soil pressure on the long side of the shear frame 2, ensuring the frame maintains a square structure under dynamic loads and avoiding soil displacement errors caused by bending deformation.

[0107] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the solutions disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the claims.

Claims

1. A shaking table experimental model box, characterized in that, include: Bottom frame; Multiple shearing frames are stacked on the bottom frame; Multiple shearing frames are fitted together to form an upward-opening receiving cavity, which is used to place experimental samples. A top block, disposed on the shear frame, is used for rolling action in any direction between two adjacent shear frames; A truss, mounted on the long side of the shear frame, is used to reinforce the sidewalls of the shear frame. Prestressing tendons; the two ends of the prestressing tendons are respectively disposed on the two short sides of the shear frame, and the prestressing tendons cooperate with the truss to apply prestress to the truss; The truss is provided with a guide rail assembly, and the guide rail assemblies of two adjacent trusses cooperate to allow the two adjacent shear frames to slide against each other; The guide rail assembly includes: The first guide rail is installed on the top wall of the truss; The second guide rail is disposed on the bottom wall of the truss; the slider of the first guide rail is connected to the slider of the second guide rail; the slider of the first guide rail of the truss is connected to the slider of the second guide rail of the adjacent truss, and the first guide rail and the second guide rail are cross-connected by sliders; The truss includes: Multiple support rods are provided on the long side of the shear frame; the length of the multiple support rods gradually shortens from the midpoint of the shear frame to both sides, and the prestressing tendons are arranged in an arc shape along the outer wall of the multiple support rods.

2. The shaking table experimental model box according to claim 1, characterized in that, One end of the prestressing tendon is fixedly disposed on the first short side of the shear frame, and the other end is disposed on the second short side of the shear frame through a snap-fit ​​assembly. The prestress applied by the prestressing tendon to the support rod can be adjusted through the snap-fit ​​assembly.

3. The shaking table experimental model box according to claim 1, characterized in that, The surface of the shear frame is provided with multiple upward-facing recessed grooves, which correspond to the bottom wall of the upper layer of the shear frame. An adjustment component is provided inside the recessed groove, which cooperates with the top block so that the top block extends upward into the recessed groove and abuts against the shear frame.

4. The shaking table experimental model box according to claim 3, characterized in that, The adjustment component is any one of a spring, a hydraulic telescopic rod, and an inflatable airbag.

5. A shaking table experimental model box according to claim 3, characterized in that, The top block is a bullseye bearing, and the side wall of the bullseye bearing is provided with rollers, which abut against the side wall of the settling trough.

6. The shaking table experimental model box according to claim 1, characterized in that, It also includes: Multiple lifting bases are disposed on the surface of the vibration table; A bottom reinforcement layer is disposed on the surface of the plurality of lifting bases; the shear frame is located on the bottom reinforcement layer, and a reinforcing rib is provided between the bottom reinforcement layer and the lifting base.

7. A method for assembling a model box, based on a shaking table experimental model box according to any one of claims 1-6, characterized in that, include: Multiple shear frames are stacked on the bottom frame and aligned to form the receiving cavity; The plastic film is placed concavely into the receiving cavity; The experimental soil was placed inside the plastic film and moistened. Adjust the prestressing tendons to keep the sidewalls of the shear frame straight, and start the vibration table to conduct the experiment.

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