Vibrating table experiment model box and assembling method of model box

Abstract

The invention relates to the technical field of geotechnical engineering, and discloses a vibrating table experiment model box and an assembly method of the model box, the vibrating table experiment model box comprises a bottom frame, a plurality of shearing frames, a top block, a truss and prestressed tendons, the bottom frame is arranged on a vibrating table, and the multiple shearing frames are arranged on the surface of the bottom frame in a stacked mode; a containing cavity with an upward opening is defined by the multiple shearing frames and used for containing experimental samples, trusses are arranged on the long edges of the shearing frames, and prestressed tendons are arranged on the trusses; the trusses are arranged on the long edges of the shearing frame, the side walls of the shearing frame can be effectively reinforced, and therefore the situation that the shearing frame deforms is avoided; meanwhile, prestressed tendons are arranged on the trusses, prestress can be applied to the trusses, and the stability of the shearing frame is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical engineering, and in particular to a vibration table test model box and an assembling method of the model box. Background Art

[0002] In geotechnical shaking table tests, a test soil box is used to contain model soil. Once the model soil is filled, the lateral earth pressure exerted on the box compresses it. Large amounts of fill can severely cause the box to flex, leading to deformation of the soil mass extending toward its surrounding boundaries. To better simulate the shear deformation of the original soil under earthquake action and reduce the "model box effect," the model soil box is typically designed as a layered structure capable of shear deformation.

[0003] In order to enable different layers of frames to move independently, the existing layered shear soil boxes in China usually adopt the method of setting balls between two adjacent layers of frames, so that the longitudinal and lateral movement between adjacent frames can be achieved; however, in experiments, there is no limit on the length of the frame. In experiments with longer model boxes, the experimental soil will be squeezed toward the long side walls of the frame during filling, and the longer frame or model box side walls will deform, resulting in cracks after the coordinated deformation of the soil and the side walls, which will affect the experiment.

[0004] In view of this, the existing technology still needs to be improved and developed. Summary of the Invention

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a vibration table test model box and an assembly method for the model box, aiming to solve the problem in the prior art that the frame is easily deformed by being squeezed when the experimental soil is filled, thereby causing the soil to crack and affecting the experiment.

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows:

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

[0008] bottom frame;

[0009] A plurality of shearing frames are stacked on the bottom frame; the plurality of shearing frames cooperate to enclose a receiving cavity with an upward opening, and the receiving cavity is used to place the experimental sample;

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

[0011] trusses, provided on the long sides of the shear frame, for reinforcing the side walls of the shear frame;

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

[0013] Furthermore, the trusses are provided with guide rail assemblies, and the guide rail assemblies of two adjacent trusses cooperate with each other to enable the two adjacent shear frames to slide relative to each other.

[0014] Furthermore, the guide rail assembly includes:

[0015] a first guide rail, disposed on the top wall of the truss;

[0016] The second guide rail is arranged 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] A plurality of support rods are arranged on the long sides of the shearing frame; the lengths of the plurality of support rods are gradually shortened from the midpoint of the shearing frame toward both sides.

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

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

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

[0022] Furthermore, the top block is a bull's eye bearing, and a roller is provided on the side wall of the bull's eye bearing, and the roller abuts against the side wall of the sink.

[0023] Furthermore, it also includes:

[0024] A plurality of lifting bases are arranged on the surface of the vibration table;

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

[0026] A method for assembling a model box, based on the above-mentioned vibration table test model box, comprises:

[0027] stacking a plurality of the shear frames on the bottom frame and aligning them to form the accommodating cavity;

[0028] placing the plastic film into the accommodating cavity in a concave shape;

[0029] Putting the experimental soil into the plastic film and moistening it;

[0030] The prestressed tendons were adjusted so that the side walls of the shear frame remained straight, and the vibration table was started to conduct the experiment.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] In the present invention, the bottom frame is arranged on the vibration table, and a plurality of shear frames are arranged in a stacked manner on the surface of the bottom frame. The plurality of shear frames are combined to form a accommodating cavity with an opening facing upward for placing experimental samples. Trusses are arranged on the long sides of the shear frames, and prestressed tendons are arranged on the trusses. By arranging trusses on the long sides of the shear frames, the side walls of the shear frames can be effectively reinforced, thereby avoiding deformation of the shear frames. At the same time, prestressed tendons are arranged on the trusses, and prestress can be applied to the trusses, thereby further improving the stability of the shear frames. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 2 This is a schematic diagram of the bull's eye bearing structure of the present invention.

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

[0036] Figure 4 This is a schematic diagram of the top view of the model box 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 flow chart of the vibration table experimental method of the present invention.

[0040] The numbers in the figure indicate: 1. Bottom frame; 11. Lifting base; 12. Bottom reinforcement layer; 2. Shear frame; 21. Sink; 3. Enclosure; 4. Top block; 41. Roller; 5. Adjustment assembly; 6. Truss; 61. Support rod; 62. First guide rail; 63. Second guide rail; 7. Prestressed tendons. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solution and effect of the present invention clearer and more specific, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0042] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0043] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0044] In view of the shortcomings of the existing technology, this embodiment provides a vibration table test model box and an assembly method of the model box, which can be specifically referred to as follows:

[0045] As attached Figure 1 and attached Figure 2As shown, a vibration table test model box includes a bottom frame 1, multiple shear frames 2, a top block 4, a truss 6 and a prestressed tendon 7. The bottom frame 1 is arranged on the vibration table, and the surface of the bottom frame 1 is provided with multiple shear frames 2 in a stacked manner. The multiple shear frames 2 are combined to form a accommodating cavity with an upward opening for placing experimental samples; a top block 4 is provided on the shear frame 2, and the top block 4 is in contact with the shear frame 2 of the upper layer, so as to allow rolling in any direction between two adjacent shear frames 2; the truss 6 is provided on the long side of the shear frame 2 for reinforcing the long side of the shear frame 2; the two ends of the prestressed tendon 7 are respectively provided on the two short sides of the shear frame 2, and the prestressed tendon 7 cooperates with the side walls of the multiple support rods 61 to apply prestress to the multiple support rods 61.

[0046] The bottom frame 1 is the foundational steel structure that supports the shear layer. It can be constructed using welded truss beams, providing stable support for the superstructure. The lifting base 11 is fixed to the vibration table. Diagonal braces and a bottom reinforcement layer 12 allow for a larger model box size, enabling larger-scale vibration experiments on a limited table surface. The shear frame 2 is a stacked arrangement of rigid frame units, such as a rectangular frame formed by splicing channel steel. Each layer of the frame forms a chamber.

[0047] Prestressed tendons 7 are flexible members with pre-tensioned stress, specifically made of stranded steel or high-strength steel wire rope. Their ends are anchored to the short sidewalls of the shear layer via anchors. Support rods 61 are supporting members distributed along the long sides of the shear layer, specifically made of channel steel or I-beams. Support rods 61 are symmetrically arranged to form the truss 6 structure, with prestressed tendons 7 arranged along the sidewalls of support rods 61.

[0048] Specifically, the pre-tension of the prestressed tendons 7 acts on the truss 6 structure and then acts on the side walls of the shear frame 2; first, multiple shear frames 2 are stacked, and adjacent shear frames 2 are in contact with each other through the top blocks 4, so that the two adjacent shear frames 2 can roll in any direction; experimental soil is placed in the accommodating cavity and moistened, and then the prestress of the truss 6 can be adjusted through the prestressed tendons 7, thereby ensuring the straightness of the long side walls of the shear frame 2, which is convenient for simulation experiments.

[0049] Compared to existing technologies, traditional layered shear boxes rely on the rigidity of the shear frame 2 to resist deformation, making them prone to bending instability in long-span structures. This application utilizes trusses 6 and a prestressed active reinforcement mechanism to establish a reverse stress field after soil loads are applied to balance lateral forces, strictly controlling the flatness of the shear frame.

[0050] Through the above-mentioned technical solution, the present 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 prestressed constraint of the prestressed tendons 7 prevents the overall instability of the shear frame 2. The active reinforcement mechanism of the prestressed tendons 7 maintains the stability of the shear frame 2 during the initial preparation, ensuring that the shear deformation of the soil is consistent with the actual earthquake response, and improving the reliability of the experimental data.

[0051] In this embodiment, a panel 3 is provided on the top of the topmost shear frame 2. The panel 3 is annular and cooperates with the opening of the accommodating cavity to increase the depth of the accommodating cavity; at the same time, it prevents the experimental soil or water from splashing when the experimental soil is moistened and during the experiment.

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

[0053] The truss 6 bears most of the vertical load of the model box, while the top block 4 bears a smaller portion. The truss 6 is a support structure composed of multiple support rods 61, and can be a long strip. The guide rail assembly is a sliding guide structure composed of a first guide rail 62 and a second guide rail 63. Specifically, the first guide rail 62 on the top wall and the second guide rail 63 on the bottom wall are connected by sliders. The guide rail assemblies of adjacent trusses 6 are cross-connected by 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 layers to perform relative displacement along a preset sliding trajectory. The guide rails in both directions can deform cooperatively to achieve shear deformation in any direction in the horizontal plane. The linkage between 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 achieve the movement of adjacent shear frames 2. However, excessive force on the ball bearings can damage them, and the ball bearings limit the movement distance between shear layers. Once the edge of a shear layer moves past the ball bearings, it is no longer subject to vertical force and directly presses against the shear layer below. This solution enhances the bending resistance of the shear frame 2 through the truss 6 structure, allowing the shear frame 2 to remain flat under soil pressure. Simultaneously, the combination of two guide rail assemblies allows for sliding in any direction within the horizontal plane. The length of the guide rails provides limited protection, preventing adjacent shear layers from sliding out.

[0056] Furthermore, the interaction between 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, the two adjacent trusses 6 always maintain a close fit during the vibration process, 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 arranged on the short side of the shear frame 2, and the truss 6 is arranged on the long side of the shear frame 2; an I-beam is arranged on the short plate of the shear frame 2 for reinforcement.

[0059] As attached Figure 5 As shown, the present application further proposes that the guide rail assembly includes a first guide rail 62 and a second guide rail 63, the first guide rail 62 is arranged on the top wall of the truss 6, and the second guide rail 63 is arranged on the bottom wall of the truss 6; the sliders of the first guide rails 62 of the two adjacent trusses 6 are connected to the sliders of the second guide rails 63.

[0060] Among them, the first guide rail 62 refers to a linear sliding component installed on the top bearing surface of the truss 6, which can be specifically implemented by a T-slot guide rail combined with a ball slider, and is used to guide the shear frame 2 to move in the horizontal direction. The first guide rail 62 refers to a linear sliding component installed on the bottom bearing surface of the truss 6, which can be specifically installed in the same manner as the first guide rail 62, and is 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 two sliders through a rigid connecting rod or a connecting plate, for example, 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 the trusses 6 refers to connecting the first guide rail 62 slider at the top of the current truss 6 with the second guide rail 63 slider at the bottom of the adjacent truss 6 through a hinge pin, for example, using a universal joint connector to achieve multi-directional freedom constraints.

[0061] Specifically, when shear frame 2 moves, upper trusses 6, guided by first and second guide rails 62 and 63, slide longitudinally or transversely along shear frame 2. Adjacent trusses 6 form a linkage system via cross-layer connected sliders. During lateral displacement, universal joints allow adjacent shear frames 2 to slide relative to each other in the XY plane, enabling shear deformation in either direction within the plane.

[0062] Compared to existing technologies, traditional single-layer ball bearings are prone to detachment from the abutting shear frame 2 in long-span frames, resulting in overload on the remaining balls and an inability to guide the movement of the shear frame 2. This solution utilizes a bidirectional constraint formed by the linkage of upper and lower guide rails, breaking down the deformation of the shear frame 2 into two synchronized displacements, avoiding stress concentration at a single support point. Furthermore, the interaction of the first and second guide rails 62, 63 allows the truss 6 to slide freely over large dimensions in the XY plane.

[0063] Through the above technical solution, the present 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 constraints of the upper and lower guide rails reduce the force on the bull's eye bearing and increase the service life of the bull's eye 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 be arbitrarily slid in the XY plane.

[0064] As attached Figure 5 As shown, the present application further proposes a truss 6 structure of a vibration table test model box, which includes a plurality of support rods 61 arranged on the long sides 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 reasonably utilize steel, the length of the support rod 61 is gradually shortened from the midpoint of the shear frame 2 to both sides.

[0066] Among them, multiple support rods 61 can be arranged in a staggered manner, thereby improving the support effect on the side wall of the shear frame 2; at the same time, the arrangement of 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 struts 61 gradually decreases from the center of the shear frame 2 sidewalls toward the sides, the prestressed tendons 7 are arranged in an arc along the outer walls of the multiple struts 61, with the center of the shear frame 2 sidewalls being the highest point. When soil pressure acts on the shear layer frame, the force exerted on the struts 61 and the torque generated by the prestressing force offset each other, thereby suppressing deformation of the long sidewalls of the shear frame 2. Simultaneously, the continuous tensioning of the prestressed tendons 7 creates a coordinated force-bearing system among the multiple struts 61.

[0068] Furthermore, the support rod 61 can also be a semicircular arc rod, with both ends of the arc rod being arranged on the side walls of the shear frame 2, and multiple arc rods being arranged in an array along the length direction of the side walls of the shear frame 2, and multiple arc rods can be in a staggered state. Through the arc rods and the staggered manner of the arc rods, the shear frame 2 can be effectively prevented from being deformed under the action of the lateral force of the soil layer.

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

[0070] As attached Figure 4 and attached Figure 5As shown, the present application further proposes that one end of the prestressed 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 assembly, and the prestress applied by the prestressed tendon 7 to the support rod 61 can be adjusted through the snap assembly.

[0071] The prestressed tendon 7 is a high-strength material component used to apply tension, and can be implemented using steel strands or carbon fiber bundles. Through tension, it generates a reverse restraining force on the support rod 61 to offset the lateral pressure of the soil. The buckle assembly is a fixing device with adjustable connection tightness, and can be implemented using a threaded locking mechanism or a ratchet clamp, or through the adjustment method of a belt in the prior art. By changing the fastening position of the buckle, the effective length of the prestressed tendon 7 is adjusted, thereby controlling the amount of prestress applied to the support rod 61.

[0072] Specifically, one end of the prestressed tendon 7 is fixed to the first short side to form an anchoring foundation, and the other end is arranged on the side wall of the support rod 61 and connected to the snap assembly on the second short side. When the shear frame 2 of the model box is deformed due to excessive length or soil pressure, the operator can shorten the effective length of the prestressed tendon 7 by adjusting the locking position of the snap assembly, thereby increasing the squeezing force on the support rod 61 and restoring the shear frame 2 to a straight state under the action of prestress. This dynamic adjustment mechanism enables the shear frame 2 to always maintain uniformly distributed prestress during the experiment, thereby resisting the bending deformation of the shear frame 2. After the experimental filling is completed, the shear frame 2 of the lower layer is subjected to greater force than the upper shear frame 2. The prestress of each layer can be adjusted according to the force conditions of the shear frame 2, and the flatness of each layer of the shear frame 2 can be strictly controlled.

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

[0074] As attached Figure 5 and attached Figure 6 As shown, the present application further proposes that the surface of the shear frame 2 is provided with a plurality of upward-opening sinking grooves 21, and the sinking grooves 21 correspond to the bottom wall of the shear frame 2 of the upper layer; a top block 4 is vertically slidably arranged in the sinking groove 21, and an adjustment component 5 is also provided in the sinking groove 21. Through the setting of the adjustment component 5, the top block 4 can be driven to extend upward out of the sinking groove 21 and abut against the bottom of the shear frame 2.

[0075] The recessed groove 21 is a square groove machined into the frame surface. The top block 4 is a bull's eye bearing, a spherical rolling element with multi-directional rolling capabilities, such as a spherical bearing with an internal ball cage, which rotates freely within the recessed groove 21. The adjustment assembly 5 is an actuator that controls the bearing's elevation, such as a sleeve structure with a built-in spring, which adjusts the bearing's support height by preloading the spring.

[0076] Specifically, the bottom frame 1 establishes a stable support platform, and multiple stacked shear frames 2 achieve inter-layer sliding through the top block 4 in the sink 21. During installation, the bottom of the frame is in a tilted state, and the adjustment component 5 pushes the bearing to move vertically along the sink 21 to compensate for the contact surface gap caused by the deformation of the shear frame 2. The top block 4 in the sink 21 can not only realize the movement of the shear frame 2, but also adjust the height to maintain uniform contact pressure. The enclosure 3 closes the top of the accommodating cavity to form a complete experimental space. Each layer of shear frame 2 forms a dynamic support system through adjustable bearings, and provides support force through the bull's eye bushing during vibration to achieve the purpose of the test.

[0077] Compared to existing technologies, traditional solutions use fixed-height ball bearings, which cannot adapt to uneven contact surfaces caused by frame deformation. This solution uses a liftable top block 4 in conjunction with an adjustment assembly 5 to adjust the support point height in real time, eliminating gaps caused by bending of the shear frame 2. This dynamic adjustment mechanism effectively solves the stress concentration problem caused by deformation of the long shear frame 2.

[0078] Through the above-mentioned technical solution, this application achieves dynamic compensation of interlayer support height, ensuring uniform force on the contact surface of each layer of shear frame 2. The top block 4 always maintains effective contact under the action of the adjustment component 5, avoiding support failure caused by deformation of the shear frame 2. The trough 21 also limits the direction of bearing movement, preventing unexpected displacement from interfering with experimental data. This design significantly improves the structural stability of the long-scale model box and provides reliable guarantees for accurately simulating soil shear deformation.

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

[0080] Among them, a spring refers to an elastic element that can undergo elastic deformation when subjected to an external force and return to its original shape after the external force is removed. Specifically, it can be implemented by a coil spring or a disc spring, and its elastic modulus can be selected from different materials or structural forms according to the actual support requirements. A hydraulic telescopic rod refers to a rod-shaped component that achieves telescopic movement through hydraulic drive. Specifically, a single-acting or double-acting hydraulic cylinder structure can be used, and the pressure of the hydraulic system can be adjusted to control the size of the support force. An inflatable airbag refers to a closed cavity made of a flexible material that generates expansion force by filling it with compressed gas. Specifically, it can be made of rubber or polyurethane materials, and the air pressure inside the airbag can be adjusted by an external air pump.

[0081] Specifically, when the model box frame experiences local bending along its length, the spring automatically adjusts the vertical support force through elastic deformation, ensuring that the top block 4 always maintains contact with the upper shear frame 2. The hydraulic telescopic rod can precisely adjust the 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 the internal air pressure, flexibly adapting to the bending deformation of the shear frame 2. During the experiment, the adjustment component 5 dynamically adjusted the vertical position of the top block 4 according to the displacement changes of the shear frame 2, ensuring that the pressure on the shear frame 2 is evenly distributed, avoiding the top block from losing contact or stress concentration due to local deformation of the shear frame 2.

[0082] Through the above technical solution, the present application solves the problem of poor ball contact caused by the self-deformation of the long shear frame 2, maintains stable contact between the shear frames 2 by dynamically adjusting the supporting force, and at the same time disperses the local effect of soil pressure on the structure of the shear frame 2, preventing the shear frame 2 from undergoing irreversible bending deformation, and ensuring the accuracy of the soil boundary conditions during the experiment; at the same time, the present application provides a variety of dynamic adjustment methods, which can be selected according to experimental requirements.

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

[0084] As attached Figure 3 As shown, the present application further proposes that the top block 4 is a bull's eye bearing, and the side wall of the bull's eye bearing is provided with a roller 41 , and the roller 41 abuts against the side wall of the sink 21 .

[0085] The roller 41 is a cylindrical or spherical rolling element with a rotational axis. Specifically, it can be a metal wheel with a ball bearing, which transmits lateral loads through rolling contact. The sidewalls of the trough 21 are the vertical surfaces on either side of the trough 21 formed on the surface of the shear frame 2 of the mold box. Specifically, they can be constructed of hardened metal plates or polymer materials, with their surfaces machined to be smooth, flat, or curved, to constrain the motion trajectory of the roller 41.

[0086] Specifically, when the vibration table generates lateral shear force, the bull's eye bearing tends to displace within the trough 21. At this point, roller 41 forms rolling contact with the sidewalls of the trough 21, converting the sliding friction between the bull's eye bearing and the trough 21 into rolling friction. Roller 41 absorbs the displacement energy through its own rotational motion, preventing direct contact between the bull's eye bearing and the trough 21 sidewalls. This structure maintains the bull's eye bearing's load-bearing capacity while reducing the friction coefficient of the contact surface through the rolling support structure. This allows the bull's eye bearing to achieve unimpeded movement during shear deformation, ensuring the independent movement precision of the interlayer frame.

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

[0088] As attached Figure 1 As shown, the present application further proposes a plurality of lifting bases 11, which are arranged on the surface of the vibration table; a bottom reinforcement layer 12, which is arranged on the surface of the plurality of lifting bases 11; the shear frame 2 is located on the bottom reinforcement layer 12, and reinforcing ribs are arranged between the bottom reinforcement layer 12 and the lifting base 11.

[0089] The lifting base 11 refers to a distributed support structure provided on the surface of the vibration table, which can be made of metal 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 a steel plate welded structure to support the shear frame 2 and maintain the flatness of its installation surface. The reinforcing rib refers to an anti-deformation member connecting the lifting base 11 and the bottom reinforcement layer 12, which can be made of a grid structure formed by cross-welding of angle steel, I-beam or steel strips to resist the shear force and bending stress generated during the vibration process.

[0090] Specifically, the lifting bases 11 are spaced apart on the surface of the vibration table to form multiple independent support points, reducing local stress concentration by dispersing the vibration transmission path. The bottom reinforcement layer 12 covers all lifting bases 11 to form a continuous rigid surface, eliminating the tilt of the shear frame 2 caused by the uneven surface of the vibration table. Reinforcement ribs form a triangular or cross-bracing structure at the connection between the lifting bases 11 and the bottom reinforcement layer 12. This increases the bending stiffness of the contact surface to suppress deformation caused by vibration, while also constraining the horizontal displacement of the lifting base 11 and 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 rigidity of the bottom support structure of the model box during vibration. Through the cooperation of multi-point distributed support and rigid bearing layer, the flatness of the installation plane of the shear frame 2 is maintained, and stress concentration caused by shear layer misalignment is avoided. 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 the shaking table test data.

[0092] At the same time, the lifting base 11 can also be provided to expand the area of the model box. The lifting base 11 is connected to the vibration table surface by bolts to achieve the cantilevering of the vibration table model box, so that it exceeds the size range of the vibration table.

[0093] In this embodiment, the shear frame 2 at the bottom 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 shear frame 2 at the bottom.

[0094] As attached Figure 7 As shown, the present application also proposes a method for assembling a model box, based on the above-mentioned vibration table test model box, comprising the following steps:

[0095] S100 , stacking a plurality of the cutting frames on the bottom frame and aligning them to form the accommodating cavity.

[0096] The vibration table is provided 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 accommodating cavity, and then the protruding height of each bull's eye bearing is adjusted by the adjustment component 5 so that each bull's eye bearing bears the same shear force.

[0097] After the shearing frame 2 is arranged, the enclosure 3 can also be covered on the topmost shearing frame 2 and fixed by welding to increase the depth of the accommodating cavity and prevent the experimental soil or water from splashing out of the accommodating cavity.

[0098] S200, placing the plastic film into the receiving cavity in a concave shape;

[0099] Multiple stacked shear frames 2 are combined with the bottom reinforcement layer 12 to form a accommodating cavity with the opening facing upward, and then the plastic film is placed in a concave shape into the accommodating cavity to cover the gap between the two adjacent shear frames 2, making it convenient to place the experimental soil.

[0100] The plastic film can wrap the test soil to avoid direct contact between the soil and the shear layer. It can also form a closed groove with an upper opening to prevent water leakage in the test soil and simulate the free deformation state under infinite boundary conditions.

[0101] S300, placing the test soil into the plastic film and wetting it;

[0102] Place the experimental soil in a plastic film and fill it up, then inject water into the experimental soil to moisten it and meet the experimental requirements.

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

[0104] S400: Adjust the prestressed tendons so that the side walls of the shear frame remain 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 extrusion pressure on the side walls of the shear frame 2, causing the side walls of the shear frame 2 to bend. At this time, the length of the prestressed tendons 7 can be adjusted, and then the prestress of the truss 6 on the side walls of the shear frame 2 can be adjusted, so that the shear frame 2 maintains its initial square structure, that is, the side walls of the shear frame 2 remain straight, and then the experiment can be carried out.

[0106] Specifically, in the vibration table test, the vertical position of all bull's eye bearings is matched with the shear force distribution in the area where they are located by adjusting the component 5, eliminating the stress concentration caused by poor contact. The plastic film forms a flexible wrapping layer in the containment cavity, which not only isolates the direct friction between the soil and the shear layer, but also simulates the unconstrained state of the infinite field boundary on the soil through the ductility of the film itself. The shear wave propagation characteristics generated by the wetting soil during the vibration process are closer to the actual foundation response. The prestressed tendons 7 balance the bending moment of the lateral pressure of the soil on the long side of the shear frame 2 through the preload applied by the short sides at both ends, ensuring that the frame maintains a square structure under dynamic load and avoiding soil displacement errors caused by bending deformation.

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

Claims

1. A vibration table test model box, characterized in that: include: bottom frame; A plurality of shearing frames are stacked and arranged on the bottom frame; A plurality of the shear frames cooperate to enclose a receiving cavity with an upward opening, wherein the receiving cavity is used to place the experimental sample; A top block is provided on the shear frame and is used for rolling in any direction between two adjacent shear frames; trusses, provided on the long sides of the shear frame, for reinforcing the side walls of the shear frame; Prestressed tendons; the two ends of the prestressed tendons are respectively arranged on the two short sides of the shear frame, and the prestressed tendons cooperate with the truss to apply prestress to the truss.

2. A vibration table test model box according to claim 1, characterized in that: The trusses are provided with guide rail assemblies, and the guide rail assemblies of two adjacent trusses cooperate with each other to enable the two adjacent shear frames to slide relative to each other.

3. A vibration table test model box according to claim 2, characterized in that: The guide rail assembly comprises: a first guide rail, disposed on the top wall of the truss; The second guide rail is arranged 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.

4. A vibration table test model box according to claim 1, characterized in that: The truss comprises: A plurality of support rods are arranged on the long sides of the shearing frame; the lengths of the plurality of support rods are gradually shortened from the midpoint of the shearing frame toward both sides.

5. A vibration table test model box according to claim 4, characterized in that: One end of the prestressed tendon is fixedly arranged on the first short side of the shear frame, and the other end is arranged on the second short side of the shear frame through a snap assembly. The prestress applied by the prestressed tendon to the support rod can be adjusted through the snap assembly.

6. The vibration table test model box according to claim 1, characterized in that: The surface of the shearing frame is provided with a plurality of upward-opening grooves, the grooves corresponding to the bottom wall of the shearing frame of the upper layer, and an adjustment component is provided inside the groove, and the adjustment component cooperates with the top block so that the top block extends upward from the groove and abuts against the shearing frame.

7. A vibration table test model box according to claim 6, characterized in that: The adjustment component is any one of a spring, a hydraulic telescopic rod and an inflatable airbag.

8. The vibration table test model box according to claim 6, characterized in that: The top block is a bull's eye bearing, and a roller is provided on the side wall of the bull's eye bearing. The roller abuts against the side wall of the sink.

9. The vibration table test model box according to claim 1, characterized in that: It also includes: A plurality of lifting bases are arranged on the surface of the vibration table; A bottom reinforcement layer is provided on the surface of the plurality of lifting bases; the shear frame is located on the bottom reinforcement layer, and reinforcing ribs are provided between the bottom reinforcement layer and the lifting bases.

10. A method for assembling a model box, based on a vibration table test model box according to any one of claims 1 to 9, characterized in that: include: stacking a plurality of the shear frames on the bottom frame and aligning them to form the accommodating cavity; placing the plastic film into the accommodating cavity in a concave shape; Putting the experimental soil into the plastic film and moistening it; The prestressed tendons were adjusted so that the side walls of the shear frame remained straight, and the vibration table was started to conduct the experiment.

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