Visual road and bridge transition section differential settlement monitoring model test device

Abstract

The utility model discloses a visual road and bridge transition section differential settlement monitoring model test device, which relates to the technical field of settlement monitoring equipment and comprises a test box, the bottom of the test box is filled with foundation soil to form a soft soil foundation, and the soft soil foundation is filled with roadbed filling soil and foam light soil in a layered manner. The multi-layer roadbed filling soil and the foam light soil are connected to form a multi-step structure; a plurality of soil pressure sensors are arranged in each layer of foam light soil and each layer of roadbed filling soil, and a strain gauge is arranged at the bottom of each layer of foam light soil; a plurality of multi-point displacement meters which are in one-to-one correspondence with the central points of the horizontal sections of the multi-step structure are buried in the soft soil foundation, two anchor heads are arranged on the upper portion and the lower portion of the contact face between the soft soil foundation and the foam light soil and between the soft soil foundation and the roadbed filling soil respectively for each multi-point displacement meter, and one anchor head is arranged on the top face of the filled soil body. The design of the utility model is suitable for sensor position arrangement in a stepped roadbed scene, and accurate acquisition and monitoring of differential settlement data are realized.

Description

Technical Field

[0001] The utility model relates to the technical field of settlement monitoring equipment, in particular to a monitoring model test device for visualizing differential settlement of a road-bridge transition section. Background Art

[0002] The statements herein merely provide background art related to the present invention and do not necessarily constitute prior art.

[0003] Differential settlement at the bridge-road transition section is the fundamental cause of vehicle bouncing at the bridgehead and a significant factor affecting driving stability. Controlling differential settlement requires both reasonable differential settlement control standards and effective treatment measures. Traditional foundation treatment technologies cannot fundamentally address differential settlement. However, foamed lightweight soil, a lightweight, high-strength roadbed filler, when used in abutment backfill projects, not only simplifies construction techniques and improves quality, but also reduces roadbed deadweight, fundamentally reducing differential settlement. Therefore, foamed lightweight soil is widely used in abutment backfill projects on highways and other roads.

[0004] However, most existing research focuses on the mechanical properties of foam lightweight soil, the application of solid waste materials, the influence relationship between various materials, and on-site construction methods. There is little research on the bearing capacity of foam lightweight soil itself and its interaction with other structures when used as embankment filler. Moreover, the few studies are mostly numerical simulations at the theoretical level, that is, they are mainly based on modeling, derivation, and analysis, and lack indoor experimental observation and verification. The theoretical analysis is often quite different from the actual engineering practice and needs continuous adjustment and improvement. It is difficult to provide accurate data support for the research on differential settlement control of actual road and bridge transition sections. Utility Model Content

[0005] In response to the above-mentioned problems and defects in the prior art, the utility model provides a visual monitoring model test device for differential settlement of road-bridge transition sections. The proposed device is an indoor simulation test device, which can effectively simulate the stepped roadbed scenario in actual on-site engineering, and through the positional layout of soil pressure sensors, strain gauges, and multi-point displacement meters suitable for the stepped roadbed scenario, accurate acquisition and monitoring of differential settlement data can be achieved, which can provide a more accurate reference for the backfill construction of highway abutments and provide accurate data support for the research on differential settlement control of road-bridge transition sections.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A model test device for visualizing differential settlement monitoring of a road-bridge transition section includes a test box, the bottom of which is filled with foundation soil to form a soft soil foundation, and the soft soil foundation is filled with roadbed fill and foamed lightweight soil in layers, wherein the multiple layers of roadbed fill and foamed lightweight soil are connected to form a multi-level stepped structure;

[0008] Multiple soil pressure sensors are installed in each layer of foam lightweight soil and each layer of roadbed fill, and a strain gauge is installed at the bottom of each layer of foam lightweight soil; multiple multi-point displacement meters corresponding to the center points of the horizontal sections of the multi-level stepped structure are buried in the soft soil foundation. The multi-point displacement meter includes a displacement meter body and multiple soil anchor heads vertically connected to it. For each multi-point displacement meter, two anchor heads are respectively arranged at the upper and lower positions of the contact surface between the soft soil foundation and the foam lightweight soil and the roadbed fill, and one anchor head is arranged on the top surface of the soil filled in the test box.

[0009] According to a further technical solution, a plurality of soil pressure sensors are provided on the bottom surface of each layer of foam lightweight soil and each layer of roadbed fill, and the positions of the plurality of soil pressure sensors in each layer correspond to the center points of the horizontal sections of the multi-step structure.

[0010] According to a further technical solution, soil pressure sensors are also provided at the contact surface between each layer of foam lightweight soil and the side plate of the test box and at the connection surface between each layer of foam lightweight soil and the roadbed fill.

[0011] According to a further technical solution, the strain gauge in each layer is arranged at the center point of the horizontal section of the step.

[0012] According to a further technical solution, the test box is composed of two transparent side panels and two opaque side panels that are symmetrically arranged.

[0013] According to a further technical solution, a loader for loading the roadbed fill and foam lightweight soil is provided on the upper portion of the test box.

[0014] According to a further technical solution, the soil pressure sensor, strain gauge and multi-point displacement meter are all electrically connected to a data acquisition device outside the test box through wires.

[0015] According to a further technical solution, the side panels of the test box are provided with drill holes for routing wires.

[0016] According to a further technical solution, the height of each step in the multi-step structure is 0.075 to 0.15 m.

[0017] According to a further technical solution, the slope ratio of the height to the width of each step in the multi-step structure is 1:1 to 1:2.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The utility model provides a visual monitoring model test device for differential settlement of road-bridge transition sections. The proposed device is an indoor simulation test device, which can effectively simulate the stepped roadbed scene in actual on-site engineering. By positioning earth pressure sensors, strain gauges, and multi-point displacement meters suitable for the stepped roadbed scene, the accurate acquisition and monitoring of differential settlement data can be achieved. It can provide a more accurate reference for the backfill construction of highway abutments and provide accurate data support for the research on differential settlement control of road-bridge transition sections. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.

[0021] Figure 1 It is a schematic diagram of the soil filling in the monitoring model test device of the utility model;

[0022] Figure 2 It is a schematic diagram of the arrangement of strain gauges in the monitoring model test device of the utility model;

[0023] Figure 3 It is a schematic diagram of the arrangement of earth pressure sensors in the monitoring model test device of the utility model;

[0024] Figure 4 It is a schematic diagram of the arrangement of multi-point displacement meters in the monitoring model test device of the utility model.

[0025] Among them, 1. Test box; 2. Soft soil foundation; 3. Roadbed fill; 4. Foam lightweight soil; 5. Strain gauge; 6. Transparent side panel; 7. Opaque side panel; 8. Soil pressure sensor; 9. Multi-point displacement meter. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0027] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0028] like Figure 1As shown, a monitoring model test device for visualizing differential settlement of a road-bridge transition section includes a test box 1. The bottom of the test box 1 is filled with foundation soil to form a soft soil foundation 2. The soft soil foundation 2 is filled with roadbed fill 3 and foam lightweight soil 4 in layers, and the connection surface between the roadbed fill 3 and the foam lightweight soil 4 is multi-stepped, that is, multiple layers of roadbed fill and foam lightweight soil are connected to form a multi-step structure.

[0029] like Figure 2 As shown, the test chamber consists of two symmetrically arranged transparent side panels 6 and two opaque side panels 7. The chamber is filled with soil, and a loader is located above the chamber to load the roadbed fill and foam lightweight soil. Loading is performed using the loader, and the transparent side panels facilitate observation and monitoring of the loading of the soil inside the chamber, as well as differential settlement of the lightweight soil platform backfill area during loading.

[0030] like Figure 3 As shown, each layer of foamed lightweight soil and each layer of roadbed fill is equipped with multiple soil pressure sensors 8. The soil pressure sensors used in this utility model are conventional pressure sensor devices. Specifically, multiple soil pressure sensors are installed on the bottom surface of each layer of foamed lightweight soil and each layer of roadbed fill. The positions of the multiple soil pressure sensors in each layer correspond to the center points of the horizontal sections of the multi-step structure. In other words, in the vertical plane where each step is located, a soil pressure sensor is installed at the bottom of each layer of foamed lightweight soil and / or each layer of roadbed fill. Furthermore, soil pressure sensors are also installed at the interface between each layer of foamed lightweight soil and the side panels of the test chamber, as well as at the interface between each layer of foamed lightweight soil and the roadbed fill.

[0031] By burying soil pressure sensors that match the stepped roadbed scenario, it is possible to comprehensively and effectively collect pressure data on the foam lightweight soil and roadbed fill during the loading process, monitor the changing patterns of soil pressure at different depths, and the mechanical properties of the interaction between lightweight soil and other structures, thereby realizing the monitoring of differential settlement of the lightweight soil abutment backfill area. Through the layout of the soil pressure sensors, it is possible to monitor the changing patterns of soil pressure at different distances from the abutment; monitor the changing patterns of soil pressure with roadbed depth at the same position from the abutment, and quantify the improvement effect of lightweight soil on the abutment backfill pressure; monitor the size of the abutment backfill soil pressure at different roadbed depths; monitor the force transmission patterns between the contact surface of lightweight soil and conventional roadbed fill, etc., providing accurate data support for subsequent research on differential settlement control of road-bridge transition sections.

[0032] like Figure 2 As shown, a strain gauge 5 is provided at the bottom of each layer of foam lightweight soil, and the position of the strain gauge 5 in each layer is set at the center point of the horizontal section of the step.

[0033] By sticking strain gauges at the bottom of the foam lightweight soil, the tensile strain and cracking of the foam lightweight soil layer at the bottom during loading are collected and monitored, providing accurate data support for subsequent research on differential settlement control of road and bridge transition sections.

[0034] A plurality of multi-point displacement meters corresponding to the center points of the horizontal sections of the multi-level stepped structure are buried in the soft soil foundation. The multi-point displacement meter includes a displacement meter body and a plurality of soil anchor heads (the anchor heads are flanges) vertically connected thereto. For each multi-point displacement meter, two anchor heads are respectively arranged at the upper and lower positions of the contact surface between the soft soil foundation and other filling soil bodies. The other filling soil bodies include foam lightweight soil and roadbed fill, and an anchor head is arranged on the top surface of the soil body filled with the test box.

[0035] Specifically, such as Figure 4 As shown, in the present invention, four multi-point displacement meters 9 are buried in the soft soil foundation, and each multi-point displacement meter 9 includes a plurality of soil anchor heads, two of which are respectively arranged at the upper and lower positions of the contact surface between the soft soil foundation and the foam lightweight soil, and two of which are respectively arranged at the upper and lower positions of the contact surface between the soft soil foundation and the roadbed fill (since the leftmost soft soil foundation is only in contact with the foam lightweight soil, only soil anchor heads are arranged above and below this contact surface; since the rightmost soft soil foundation is only in contact with the roadbed fill, only soil anchor heads are arranged above and below this contact surface). Based on the above arrangement, the relative displacement of the contact surface between the foam lightweight soil and other structures (i.e., the soft soil foundation and the roadbed fill) can be detected, and the relative displacement (i.e., settlement) of the contact surface between the soft soil foundation at different points and other filling soil bodies above can be monitored.

[0036] Through the buried layout of the multi-point displacement meter matching the stepped roadbed scenario, the relative displacement between the foam lightweight soil and other structures can be comprehensively and effectively collected and monitored. Specifically, the amount of settlement of the roadbed top surface at different distances from the abutment can be monitored; the variation pattern of the foundation compression under different roadbed filling materials, and the improvement effect of lightweight soil on the post-construction settlement of the abutment back can be obtained at the same time; the relative displacement between the lightweight soil and the foundation soil, and the contact surface of conventional roadbed fill, etc., can provide accurate data support for subsequent research on differential settlement control of road-bridge transition sections.

[0037] In addition, the above-mentioned soil pressure sensor, strain gauge and multi-point displacement meter are all electrically connected to the data acquisition device outside the test box through wires; the side panel of the test box is provided with drill holes for wiring wires, which facilitates the wires to pass through and connect to the external data acquisition device.

[0038] Furthermore, in the actual road bridge transition section, the height of each step in the multi-step ladder structure is 0.5 to 1m, and the slope ratio of the height to the width of each step in the multi-step ladder structure is 1:1 to 1:2. Using a similarity of 20:3 and using all the devices proposed in the utility model to simulate the actual road bridge transition section, the height of each step in the multi-step ladder structure is 0.075 to 0.15m. Specifically, Figure 1 and Figure 2 As shown, in this device, the length of the test box (i.e., the length of the transparent side panels) represents the transition section length, which is 1.65m; the width of the test box (i.e., the length of the opaque side panels) represents the lane width, which is 0.75m; and the height of the test box is greater than or equal to 1.2m. The test box is filled with soil, wherein the depth of the soft soil foundation (i.e., the foundation thickness) is 0.75m. The multi-step structure is a three-step structure, and the height of the three-step structure represents the roadbed height, which is 0.45m. The height of each step is 0.15m, and the horizontal section length (i.e., width) of each step is 0.3m. The horizontal section length where the foam lightweight soil contacts the soft soil foundation represents the base length, which is 0.75m. The design of the above step height and width, etc., all meet the "Highway Roadbed Design Code JTGD30-2015" and the "Technical Code for Bubble Mix Lightweight Fill Engineering."

[0039] The specific working process of this utility model is as follows:

[0040] According to the above-mentioned visual monitoring model test device for differential settlement of road-bridge transition sections, the roadbed fill and foam lightweight soil inside the test box were filled, and the soil pressure sensor, strain gauge and multi-point displacement meter were laid out. The soil pressure sensor, strain gauge and multi-point displacement meter were connected to the external data acquisition instrument via wires.

[0041] The loading was carried out using a loader installed on the upper part of the test chamber. The differential settlement of the lightweight soil platform backfill area during the loading process was observed and monitored through the transparent side panels. The corresponding monitoring data was obtained through the data acquisition instrument, providing accurate data support for the subsequent research on differential settlement control of road-bridge transition sections.

[0042] Although the above description of the specific implementation methods of the present invention is combined with the accompanying drawings, it does not limit the scope of protection of the present invention. Technical personnel in the relevant field should understand that on the basis of the technical solution of the present invention, various modifications or deformations that can be made by technical personnel in this field without creative work are still within the scope of protection of the present invention.

Claims

1. A visual monitoring model test device for differential settlement of road-bridge transition sections, characterized by: The test box comprises a test box, the bottom of which is filled with foundation soil to form a soft soil foundation, the soft soil foundation is filled with roadbed fill soil and foam lightweight soil in layers, and the multiple layers of roadbed fill soil and foam lightweight soil are connected to form a multi-level stepped structure; Multiple soil pressure sensors are installed in each layer of foam lightweight soil and each layer of roadbed fill, and a strain gauge is installed at the bottom of each layer of foam lightweight soil; multiple multi-point displacement meters corresponding to the center points of the horizontal sections of the multi-level stepped structure are buried in the soft soil foundation. The multi-point displacement meter includes a displacement meter body and multiple soil anchor heads vertically connected to it. For each multi-point displacement meter, two anchor heads are respectively arranged at the upper and lower positions of the contact surface between the soft soil foundation and the foam lightweight soil and the roadbed fill, and one anchor head is arranged on the top surface of the soil filled in the test box.

2. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 1 is characterized in that: The bottom surface of each layer of foam lightweight soil and each layer of roadbed fill is provided with a plurality of soil pressure sensors, and the positions of the plurality of soil pressure sensors in each layer correspond to the center points of the horizontal sections of the multi-step structure.

3. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 2 is characterized in that: Soil pressure sensors are also provided at the contact surface between each layer of foam lightweight soil and the side plate of the test box, as well as at the connection surface between each layer of foam lightweight soil and the roadbed fill.

4. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 1 is characterized in that: The position of the strain gauge in each layer is set at the center point of the horizontal section of the step.

5. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 1 is characterized in that: The test box is composed of two transparent side panels and two opaque side panels that are symmetrically arranged.

6. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 1 is characterized in that: A loader for loading roadbed fill and foam lightweight soil is arranged on the upper part of the test box.

7. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 1 is characterized in that: The soil pressure sensor, strain gauge and multi-point displacement meter are all electrically connected to a data acquisition device outside the test box through wires.

8. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 7 is characterized in that: The side panels of the test box are provided with drilling holes for wiring.

9. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 1 is characterized in that: The height of each step in the multi-step structure is 0.075 to 0.15 m.

10. The visual monitoring model test device for differential settlement of a road-bridge transition section according to claim 1, characterized in that: The slope ratio of the height to the width of each step in the multi-step structure is 1:1 to 1:2.

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