Building foundation outer wall lateral earth pressure simulation applying device

Abstract

The application discloses a building foundation outer wall lateral soil pressure simulation applying device, which comprises a thrust applying device and a geotechnical lateral soil pressure simulation device; wherein the geotechnical lateral soil pressure simulation device is in the shape of a right trapezoid; the inclined surface of the geotechnical lateral soil pressure simulation device is used for abutting against the geotechnical material; the thrust applying device is used for applying a thrust to the right angle surface of the geotechnical lateral soil pressure simulation device, so that the geotechnical lateral soil pressure simulation device is in close contact with the geotechnical material; and the device is helpful to solve the problems that the distribution rule of the lateral pressure applied to the building foundation lateral wall by horizontally moving a flat thrust plate does not conform to the actual situation, the lateral pressure applied to the position with a relatively shallow buried depth is too large, and the lateral pressure applied to the position with a relatively deep buried depth is relatively small.

Description

Technical Field

[0001] This invention belongs to the field of building technology, specifically a device for simulating and applying lateral earth pressure on the exterior walls of building foundations. Background Technology

[0002] Scaled-down model testing is an important method for simulating the vibration reduction effect of building foundations. In engineering applications, when controlling vibration of building foundations, it is usually necessary to isolate and block the propagation path of the vibration by means of the foundation slab and side walls, such as installing vibration isolation pads under the foundation slab and on the basement side walls.

[0003] In conducting vibration reduction experiments on scaled-down models of buildings, it is usually necessary to implement corresponding vibration reduction measures for the building foundation and sidewalls. The design of vibration control measures for the building foundation in engineering projects requires considering the compressive stress level of the building model's base to design the natural frequency of the isolation system, thereby refining the relevant parameters of the isolation materials and carrying out the installation of the base materials. When selecting side pads, the lateral earth pressure load on the actual building foundation sidewalls must be considered. In experimental studies of the vibration reduction effect of scaled-down models of buildings, the natural frequency of the model experiment and the lateral pressure on the scaled-down model's foundation sidewalls must be determined based on the natural frequency of the isolation system in the actual project, the lateral pressure load on the building foundation sidewalls, and the similarity coefficients of the scaled-down experimental model.

[0004] Research and analysis revealed that some scholars have designed and invented compressive stress experimental devices that simulate building foundations and sidewalls. Some of these scholars use sandbox models for simulation. During the experiment, relevant soil and rock media are backfilled around the basement of a scaled-down model of the building to apply lateral pressure from the soil and rock materials of the building foundation sidewalls to the basement sidewalls. However, in this method, the vibration transmission medium in the fabrication of the experimental box is entirely soil and rock. Therefore, repeated excavation, backfilling, and compaction of the soil and rock media are required for various experimental conditions, resulting in a long experimental cycle. Furthermore, this method requires a high degree of consistency in the compaction level.

[0005] In addition, some scholars have designed and developed experimental devices to simulate lateral earth pressure on underground structures of building foundations, based on experimental requirements. These devices involve installing a horizontally moving, straight push plate along the building's sidewalls. A power source applies a specified lateral thrust to the push plate to further simulate the lateral pressure on the foundation's sidewalls. The level of lateral pressure application is treated to be equivalent to actual earth pressure. This experimental device can precisely adjust the equivalent lateral earth pressure on the building foundation, but it cannot reflect the characteristic that the lateral earth pressure on the foundation gradually increases with the building's burial depth, as shown in the attached figure. Figure 1As shown in the figure, γ represents the unit weight of the soil and rock medium; K0 represents the lateral pressure coefficient; and H represents the burial depth of the soil and rock medium. Therefore, the experimental setup exerts a greater constraint force on the sidewall region of the building foundation near the ground surface, and a relatively smaller constraint force on the region closer to the foundation. This will inevitably have an additional impact on the vibration of the building structure during the experiment.

[0006] Therefore, how to solve the problem that the lateral pressure applied to the sidewall of the building foundation by moving the horizontally straight push plate does not match the actual situation, and that the lateral pressure applied to shallower locations is too large, while the lateral pressure applied to deeper locations is too small, has become the key issue of current research. Summary of the Invention

[0007] In view of the above problems, the present invention provides a device for simulating the application of lateral earth pressure on the exterior wall of a building foundation, which at least solves some of the above-mentioned technical problems. By simulating the interaction between soil and rock materials and experimental models, it helps to solve problems such as the lateral pressure applied to the side wall of a building foundation by moving a horizontally straight push plate in reality not matching the actual situation, the excessive lateral pressure applied at shallow locations, and the insufficient lateral pressure applied at deep locations.

[0008] The present invention provides a device for simulating and applying lateral earth pressure on the exterior wall of a building foundation, comprising: a thrust application device (1) and a soil and rock lateral earth pressure simulation device (2);

[0009] The soil pressure simulation device (2) is in the shape of a right trapezoid;

[0010] The inclined surface of the soil pressure simulation device (2) is used to abut against the soil material;

[0011] The thrust application device (1) is used to apply thrust to the right-angled surface of the soil pressure simulation device (2) so that the soil pressure simulation device (2) is in close contact with the soil material.

[0012] Furthermore, the soil and rock material is located between the basement side wall of the building model and the soil and rock pressure simulation device (2).

[0013] Furthermore, the soil pressure simulation device (2) includes a constraint box (21), a pressure regulating airbag (22), and a direct action plate (23);

[0014] The constraint box (21) is provided with multiple transverse partitions, and each transverse partition is provided with the pressure regulating airbag (22);

[0015] The upper end of the opening side of the constraint box (21) is hinged to the direct action plate (23); the direct action plate (23) is used to abut against the soil and rock material.

[0016] Furthermore, the initial length of the pressure regulating airbag on each of the transverse partitions is a preset size longer than the initial length of the pressure regulating airbag on the previous transverse partition.

[0017] Furthermore, the upper end of the opening side of the constraint box (21) is hinged to the direct action plate (23) via the constraint shaft (24).

[0018] Furthermore, the direct action plate (23) is composed of multiple plate-shaped structures connected by hinges.

[0019] Furthermore, a pair of fixed slide rails (25) are installed on both the upper and lower sides of the constraint box (21); the constraint box (21) is slidably connected to the fixed slide rails (25);

[0020] After the thrust application device (1) applies a thrust to the other side of the opening of the constraint box (21), the constraint box (21) slides laterally on the fixed slide rail (25).

[0021] Furthermore, the constraint box (21) is slidably connected to the fixed slide rail (25) via the constraint ear (26).

[0022] Compared with the prior art, the lateral earth pressure simulation application device for building foundation exterior walls described in this invention has the following beneficial effects:

[0023] This invention is applied to a scaled-down model test chamber with a basement structure, where a small amount of soil and rock is filled around the building. A thrust application device laterally pushes the soil pressure simulation device to achieve the horizontal constraint of the soil lateral on the building foundation in that direction; the simulation of soil pressure is achieved by precisely adjusting the lateral thrust of the thrust application device.

[0024] This invention can determine the length difference between the uppermost and lowermost high-precision pressure-adjusting airbags based on commonly used soil lateral pressure parameters, directly simulating the real lateral earth pressure distribution. Furthermore, based on the experimental device of this invention, which is designed for a special triangular earth pressure distribution, the triangular soil pressure of specific soil types can be achieved by precisely adjusting the pressure of each airbag after compression. This allows for accurate simulation of triangular earth pressure in different soil types (in this embodiment, the cross-section of the soil lateral pressure simulation device is trapezoidal, and the lateral earth pressure applied during operation is the simulated soil lateral pressure; in real life, the lateral pressure of the foundation sidewall of a building basement exhibits a triangular distribution).

[0025] In this invention, by setting different initial lengths of the pressure-regulating airbags before they are compressed, the pressure of the airbags at different depths after they are compressed is achieved, and finally the direct action plate applies different pressures to the outside at different depths, thus achieving the application of different lateral pressures that vary with depth.

[0026] In this invention, the soil and rock materials between the direct-acting plate and the basement structure can be arbitrarily replaced, thereby quickly simulating different soil and rock materials and solving the problem of repeated and large-scale excavation of soil and rock in traditional experiments.

[0027] Traditional scaled-down model test chambers apply lateral pressure to the perimeter of underground structures using a full soil and rock medium. The magnitude of this lateral pressure depends on the experimenter's extensive experience in compacting the soil and rock. In contrast, this invention allows for the lateral movement of the soil pressure simulation mechanism by adjusting a high-precision thrust application mechanism. This enables rapid application and unloading of lateral soil pressure, saving the cost of hiring professional soil and rock testing personnel and improving experimental efficiency.

[0028] This invention only requires a small amount of soil and rock material to be buried at the location of the direct action plate and the basement side wall of the building model to achieve a realistic simulation of the soil and rock friction coefficient.

[0029] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0030] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0031] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0032] Figure 1 A schematic diagram of the lateral static earth pressure distribution provided for existing related technologies.

[0033] Figure 2 This is a schematic diagram of the lateral static earth pressure distribution provided for an embodiment of the present invention.

[0034] Figure 3 This is a schematic diagram of the structure of the lateral earth pressure simulation application device for the exterior wall of a building foundation provided in an embodiment of the present invention.

[0035] Figure 4 This is a schematic diagram of the structure before load application, provided in an embodiment of the present invention.

[0036] Figure 5 This is a schematic diagram of the structure after load application, provided for an embodiment of the present invention.

[0037] Figure 6 This is a schematic diagram illustrating the principle before load application, provided in an embodiment of the present invention.

[0038] Figure 7 This is a schematic diagram illustrating the principle after load application, provided in an embodiment of the present invention. Detailed Implementation

[0039] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0040] In this embodiment of the invention, to accurately simulate the lateral earth pressure of the building structure based on actual conditions, the basement sidewall of the building model is set as a vertical wall, and the basement sidewall of the building model is in a state of static equilibrium with the lateral soil and rock materials. The formula for calculating the static earth pressure of the soil and rock materials is expressed as:

[0041] Vertical force: E = γH

[0042] Horizontal force: E0=γK0H

[0043] Where γ represents the unit weight of the soil and rock material; K0 represents the lateral pressure coefficient; and H represents the burial depth of the soil and rock material.

[0044] Based on the above formulas for calculating static earth pressure in geotechnical materials, it can be seen that the lateral earth pressure on a building structure increases with the increase of the structural depth. The specific distribution is as follows: Figure 2 As shown in the diagram. Based on this distribution map, the earth pressure angle is expressed as:

[0045]

[0046] Based on the distribution of lateral static earth pressure on the sidewalls of a building, this embodiment of the invention provides a device for simulating and applying lateral earth pressure on the exterior walls of a building foundation, such as... Figure 3 As shown, the device includes a thrust application device 1 and a soil pressure simulation device 2; wherein, the soil pressure simulation device 2 is a right trapezoid; the inclined surface of the soil pressure simulation device 2 is used to abut against the soil material; the soil material is located between the basement side wall of the building model and the soil pressure simulation device 2; when the thrust application device 1 applies a thrust to the right-angled surface of the soil pressure simulation device 2, the soil pressure simulation device 2 can be brought into close contact with the soil material, and the specific thrust applied can be precisely controlled.

[0047] The aforementioned soil and rock lateral pressure simulation device 2 includes a constraint box 21, a pressure regulating airbag 22, and a direct action plate 23; wherein:

[0048] The constraint box 21 is equipped with multiple transverse partitions, and each transverse partition is equipped with a pressure regulating airbag 22. The initial length of the pressure regulating airbag on each transverse partition is a preset size longer than the initial length of the pressure regulating airbag on the previous transverse partition. Finally, these multiple pressure regulating airbags form an inclined plane. In this embodiment of the invention, there are a total of 5 transverse partitions, and each transverse partition is equipped with a pressure regulating airbag, which are called airbag 1, airbag 2, airbag 3, airbag 4 and airbag 5 from bottom to top. Among them, the length of airbag 1 is the same as the length of the constraint box, and each subsequent airbag is a preset size longer than the previous airbag, so that the shape of the last 5 airbags is exactly the hypotenuse of a right trapezoid, that is, the inclined plane of the soil pressure simulation device 2.

[0049] The opening side of the constraint box 21 (i.e. Figure 3 The upper end of the left side of the constraint box 21 is hinged to the direct action plate 23; the direct action plate 23 is used to abut against the soil and rock material. In this embodiment of the invention, the upper end of the opening side of the constraint box 21 is hinged to the direct action plate 23 through the constraint shaft 24; the direct action plate 23 is composed of multiple plate-shaped structures hinged together, the number of plate-shaped structures is the same as the number of airbags, and each plate-shaped structure corresponds to one airbag; based on this, the force of each airbag acts on the corresponding plate-shaped structure, which can ensure that the airbag pressure can be directly transmitted to the soil and rock structure through the plate-shaped structure, without being affected by the pressure of adjacent airbags;

[0050] The aforementioned soil and rock materials refer to different names for soil, rock, and other soil and rock structures on the earth; including miscellaneous fill, clay, silt, sand, gravel, mudstone, etc. Due to different geological conditions in different regions, the soil and rock materials selected will also vary.

[0051] A pair of fixed slide rails 25 are installed on both the upper and lower sides of the constraint box 21; the constraint box 21 is slidably connected to the fixed slide rails 25; in this embodiment of the invention, the constraint box 21 is slidably connected to the fixed slide rails 25 via constraint earrings 26; when the thrust application device 1 is on the other side of the opening of the constraint box 21 (i.e. Figure 3 After the right side of the constraint box is pushed, the constraint box 21 slides laterally on the fixed slide rail 25 through the constraint lug 26, so that the soil pressure simulation device 2 gradually comes into close contact with the soil material.

[0052] In this embodiment of the invention, a high-precision thrust application device laterally pushes the constraint box to move laterally, causing the hinged direct-acting plate 23 to directly contact the basement sidewall or soil material. During this process, multiple closed pressure-regulating airbags of different lengths with the same cross-section are laterally compressed, pushing the direct-acting plate; see [link to related documentation]. Figure 4 As shown, airbag 1 to airbag nAs the initial airbag length decreases, the pressure it bears also gradually decreases, allowing for the application of different lateral earth pressures at different burial depths. The final state of the device after the induction process is shown in [reference needed]. Figure 5 As shown, by installing different types of soil and rock materials between the push plate and the basement of the architectural model, the interaction between real soil and rock and the experimental model is simulated. During the process of the pressure-regulating airbag pushing the direct-acting plate, the direct-acting plate is compressed and rotates along the constraint axis, gradually coming into close contact with the soil and rock materials.

[0053] The working principle of the lateral earth pressure simulation application device for building foundation exterior walls provided in this embodiment of the invention will be explained below:

[0054] In this embodiment of the invention, the lateral load application device uses sealed cavities with the same cross-section S but different lengths as the main lateral pressure regulating device (i.e., pressure regulating airbag). Gas with the same initial pressure P0 is filled into the cavities. An external force pushes the entire application device to move laterally, adjusting the horizontal positional relationship between the direct-acting plate and the experimental object. This adjusts the contact degree between the direct-acting plate and the basement sidewall of the building model, simulating the magnitude of lateral earth pressure under different soil and rock materials. See the relevant schematic diagram. Figure 6 and Figure 7 As shown.

[0055] The high-precision pressure-regulating airbags are compressed relatively slowly, and the temperature change of the gas before and after compression is negligible. The initial lateral length of each high-precision pressure-regulating airbag is designed based on the ideal gas law. The distance design process is as follows:

[0056] The ideal gas law is expressed as:

[0057] PV = nRT

[0058] P represents the pressure of an ideal gas; V represents the volume of an ideal gas; n represents the amount of substance of the gas; T represents the thermodynamic temperature of an ideal gas; and R represents the ideal gas constant.

[0059] Because each airbag is sealed, there is no gas leakage before and after the airbag is compressed. Due to the slow application process, the gas temperature change is negligible. That is:

[0060] P0V0=P1V1

[0061] P0 represents the initial internal gas pressure of the airbag; V0 represents the initial internal gas volume of the airbag; P1 represents the stable internal gas pressure of the airbag after compression; V1 represents the stable internal gas volume of the airbag after compression.

[0062] The airbags in the experimental setup have the same cross-sectional area, S, and are housed within compartments of identical cross-sections. The compartment lengths differ, meaning the cross-sectional area of ​​the cavity remains unchanged before and after compression. Therefore, the above formulas can be simplified to:

[0063] P0L0=P1L1

[0064] P0 represents the initial internal gas pressure of the airbag; L0 represents the initial total length of the airbag; P1 represents the stable internal gas pressure of the airbag after compression; L1 represents the stable total length of the airbag after compression.

[0065] When the experimental setup perfectly simulated the lateral earth pressure on the building foundation, the maximum lateral earth pressure on the basement was consistent with the pressure of the lowest airbag 1. That is:

[0066] kP1=E0

[0067] k represents the similarity coefficient between the experimental conditions and the actual situation; P1 represents the gas pressure inside the airbag in the stable state after compression; E0 represents the horizontal earth pressure of the basement at a burial depth H.

[0068] The derivation and simplification yields:

[0069]

[0070] When the experimental setup perfectly simulates the actual lateral earth pressure of a building, the inclination angle of the actual lateral earth pressure slope is consistent with the angle between the direct-acting plate and the horizontal direction in the earth pressure simulation device, i.e., θ = α.

[0071] θ represents the angle between the hypotenuse of the actual lateral earth pressure and the horizontal plane (see attached diagram). Figure 2 ); The angle between the direct-acting plate and the horizontal direction in the α-rock and soil pressure simulation device (see attached figure) Figure 6 );

[0072] Derivation:

[0073]

[0074]

[0075] Right now:

[0076]

[0077] Where ΔL=L0-L1; that is, ΔL=hK0; h represents the height of the constraint box (i.e., the height of the soil pressure simulation device).

[0078] This invention, through theoretical calculations and derivation, obtains a simulation experimental device capable of fully simulating the static lateral pressure distribution characteristics of real soil and rock. The length difference between the upper and lower airbags of the experimental device should meet the requirement of ΔL (ΔL = hK0). The length difference between the uppermost and lowermost high-precision pressure-regulating airbags can be set according to commonly used soil and rock parameters. In addition, the initial pressure of each airbag should meet the requirement of P0.

[0079] This invention replaces the original, simplistic, and crude method of applying uniform load with a lateral force application device that can adjust the magnitude of the lateral constraint force for different burial depths. Considering the characteristics of lateral earth pressure in soil and rock—the deeper the burial, the greater the lateral earth pressure—arbitrary lateral earth pressure simulation can be performed by adjusting the lateral load application level of the entire lateral baffle. This not only allows for precise pressure adjustment but also optimizes the experimental process and accelerates the experimental progress. It avoids the process of repeated excavation and saves on the cost and technical difficulty of preparing the soil and rock media.

[0080] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device for simulating and applying lateral earth pressure on the exterior wall of a building foundation, characterized in that, include: Thrust application device (1) and soil pressure simulation device (2); The soil pressure simulation device (2) is in the shape of a right trapezoid; The inclined surface of the soil pressure simulation device (2) is used to abut against the soil material; The thrust application device (1) is used to apply thrust to the right-angled surface of the soil pressure simulation device (2) so that the soil pressure simulation device (2) is in close contact with the soil material; The soil pressure simulation device (2) includes a constraint box (21), a pressure regulating airbag (22), and a direct action plate (23). The constraint box (21) is provided with multiple transverse partitions, and each transverse partition is provided with the pressure regulating airbag (22). The upper end of the opening side of the constraint box (21) is hinged to the direct action plate (23); the direct action plate (23) is used to abut against the soil and rock material; The initial length of the pressure regulating airbag on each of the transverse partitions is a preset size longer than the initial length of the pressure regulating airbag on the previous transverse partition; The upper end of the opening side of the constraint box (21) is hinged to the direct action plate (23) via the constraint shaft (24); The direct-acting plate (23) is composed of multiple plate-shaped hinges.

2. The device for simulating and applying lateral earth pressure on the exterior wall of a building foundation as described in claim 1, characterized in that, The soil and rock material is located between the side wall of the building model and the soil and rock pressure simulation device (2).

3. The device for simulating and applying lateral earth pressure on the exterior wall of a building foundation as described in claim 1, characterized in that, A pair of fixed slide rails (25) are installed on both the upper and lower sides of the constraint box (21); the constraint box (21) is slidably connected to the fixed slide rails (25); After the thrust application device (1) applies a thrust to the other side of the opening of the constraint box (21), the constraint box (21) slides laterally on the fixed slide rail (25).

4. The device for simulating and applying lateral earth pressure on the exterior wall of a building foundation as described in claim 3, characterized in that, The constraint box (21) is slidably connected to the fixed slide rail (25) via the constraint ear (26).

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