A test system for studying near-field high-speed rail seismic signals

Abstract

The present invention provides a test system for studying near-field high-speed railway seismic signals, comprising: a detachable model box, a pier-foundation coupling subsystem, a soil layer drainage and consolidation subsystem, an oscillator subsystem and a signal acquisition subsystem. The test method comprises: designing a test scheme, making a coupling model, soil layer drainage and consolidation, instrument layout, oscillation and signal acquisition. Compared with the prior art, the test system of the present invention can simulate the drainage and consolidation of the high-speed railway foundation and the movement characteristics of the earthquake source, and reflect the interference phenomenon of the high-speed railway seismic signal. By establishing a reasonable mapping between the model scale and the engineering scale, the piers and foundations in the model are close to the actual situation, which is of great significance for studying the propagation and attenuation law of the near-field high-speed railway seismic signal.

Description

Technical Field

[0001] The invention relates to a test system for high-speed rail seismic signals, in particular to a test system that can be used to study near-field high-speed rail seismic signals. Background Art

[0002] As a repeatable artificial seismic source, the vibrations generated by high-speed rail during operation have an impact on the roadbed, bridges and surrounding buildings. The destructive effect of high-speed rail seismic waves on structures such as bridges and foundations cannot be ignored. Especially in some rock strata with developed cracks, seismic waves can cause the development of rock cracks. The high-speed rail foundation may sink under the long-term action of repeated seismic waves, affecting the safety of high-speed rail operations.

[0003] Conventional research on near-field high-speed rail seismic signals mostly relies on field experiments, which are extremely costly and require complex operating systems. Due to the large near-field range of actual high-speed rail and the complex and changeable geological conditions, it is impossible to accurately summarize the propagation and attenuation laws of high-speed rail seismic signals, especially in theory, there is a lack of a complete propagation and destruction mechanism. Traditional model tests can only approximately simulate the vibration response characteristics of the structure by superimposing static loads and dynamic disturbances, but cannot simulate the mobility of the earthquake source and the interference phenomenon of seismic signals. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the existing test technology, the present invention provides a test system that can be used to study near-field high-speed rail seismic signals.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A test system for studying near-field high-speed rail seismic signals, comprising:

[0007] A removable model box, supported by a rigid base, for loading the pier-foundation coupling model;

[0008] The pier-foundation coupling model, with the upper layer being soil and the lower layer being rock, is used to simulate the near-field environment of high-speed rail;

[0009] The soil drainage and consolidation subsystem applies load to the soil layer by loading the steel plate to drain and consolidate the soil layer. The free water is discharged through the drainage holes, which is used to simulate the reinforcement of the high-speed railway foundation.

[0010] The oscillator system generates vibrations through the host, controller, motor switch and variable frequency vibration motor to simulate the moving high-speed rail passing through the top of the bridge pier as the earthquake source;

[0011] The signal acquisition subsystem receives and stores near-field high-speed rail seismic signals through broadband detectors, converters, data concentrators, and a host computer;

[0012] The test method of the test system includes the following steps:

[0013] Step 1: Design the experimental plan.

[0014] Establish a reasonable mapping relationship between the model scale and the engineering scale, determine the spacing, bottom depth and top height of the model piers according to the actual high-speed rail parameters and the pier spacing, design the simulated high-speed rail train speed, determine the vibration time interval of each vibration motor, and design the size of the pier-foundation coupling model;

[0015] Step 2: Create a coupling model.

[0016] Arrange the rigid base and the bottom plate of the detachable model box in the concrete curing environment, assemble the detachable model box enclosure and fix it with long rod screws, arrange the foundation in the detachable model box, first arrange the lower rock layer, wait for the rock layer to solidify and the strength reaches 75% of the design strength, arrange the upper soil layer, and use the PVC cylinder to pour concrete to make the bridge pier. The position of the bottom and top surfaces of the PVC cylinder is determined according to the designed test plan;

[0017] Step 3: Soil drainage and consolidation,

[0018] Place a loading steel plate on the upper surface of the soil layer to compact the soil layer and allow free water to drain through drainage holes;

[0019] Step 4: Instrument layout,

[0020] Remove the panels of the detachable model box and place broadband geophones in the rock and soil layers of the pier-foundation coupling model;

[0021] Step 5: Oscillation and signal acquisition,

[0022] The controller controls the motor switch through the host, so that the variable frequency vibration motors on the top of the pier start running in sequence. The starting running time and interval of each variable frequency vibration motor depend on the simulated high-speed train speed. Finally, the near-field high-speed rail seismic signal is received and stored through the signal acquisition subsystem.

[0023] The side surface of the detachable model box is provided with protrusions, grooves and screw holes for assembling and fixing the detachable model box.

[0024] The broadband detector is arranged in the rock layer before it is completely solidified and the strength reaches 75% of the design strength. The broadband detector is arranged in the soil layer after the soil layer is drained and consolidated.

[0025] The thickness of the loading steel plate is in the range of 10-30 mm, and the weight is in the range of 157-471 kg, so that the soil layer has sufficient density after drainage and consolidation.

[0026] The rigid base is in the shape of a rectangular ring with a height ranging from 30 to 80 mm and a hollow in the middle so as to reduce the influence of seismic wave reflection on seismic signal reception.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention can simulate the drainage consolidation of high-speed railway foundation and the movement characteristics of the earthquake source.

[0029] 2. The present invention establishes a reasonable mapping between the model scale and the engineering scale, so that the bridge piers and foundations in the model are close to the actual situation, which is of great significance for studying the propagation and attenuation laws of near-field high-speed rail seismic signals.

[0030] 3. The present invention can reflect the interference phenomenon of high-speed rail seismic signals, and has beneficial conditions for the research on high-speed rail seismic wave interference.

[0031] 4. The detachable model box of the present invention is easy to install and disassemble. The model box can be used to first make a rock layer and arrange a broadband detector of the rock layer, and then make a soil layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of the test system for near-field high-speed railway seismic signals of the present invention;

[0033] Figure 2 It is a schematic diagram of a detachable model box with a rigid base according to the present invention;

[0034] Figure 3 A reference schematic diagram for the layout of the broadband detector of the present invention;

[0035] In the figure: 1-main unit; 2-controller; 3-motor switch; 4-variable frequency vibration motor; 5-converter; 6-data concentrator; 7-wideband detector; 8-detachable model box; 9-rigid base; 10-drainage hole; 11-loading steel plate; 12-concrete bridge pier; 13-soil layer; 14-rock layer; 15-fixing plug; 16-long rod screw. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0037] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0038] 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 term "comprising" is used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0039] In the present invention, the directions or positional relationships indicated by terms such as "upper", "lower", "left", "right", "front", "back", "middle", "bottom", and "top" are based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention. They do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0040] In the following description, various aspects of the present invention will be described, however, it will be apparent to those skilled in the art that the present invention may be implemented using only some or all of the structures or processes of the present invention. Specific numbers, configurations, and sequences are described for clarity of explanation, but it is apparent that the present invention may be implemented without these specific details. In other cases, some well-known features will not be described in detail in order not to confuse the present invention.

[0041] See also Figure 1-3According to the actual high-speed rail parameters and the pier spacing, the model pier spacing is determined to be 500 mm, wherein the concrete piers (12) at both ends are 250 mm away from the outer edge of the model, the bottom depth of the concrete pier (12) is 600 mm, the top height of the concrete pier (12) is 150 mm, the designed high-speed rail train speed is 300 km / h, the vibration time interval of each variable frequency vibration motor (4) is 0.6 s, and the size of the designed pier-foundation coupling model is 2000 mm (length) × 1000 mm (width) × 1000 mm (height), wherein the soil layer (13) is 200 mm thick, and the rock layer (14) is 800 mm thick. A coupling model is manufactured by arranging a rectangular ring-shaped rigid base (9) with a height of 50 mm and a hollow middle portion and a 50 mm thick bottom plate of a detachable model box (8) in a concrete curing environment, assembling a detachable model box (8) enclosure, providing a protrusion, a groove and a screw hole on the side of the detachable model box (8), and fixing the detachable model box (8) with a long rod screw (16). A foundation is arranged in the detachable model box (8), firstly arranging a lower rock layer (14), and arranging an upper soil layer (13) after the rock layer (14) solidifies and the strength reaches 75% of the design strength. Concrete is poured in a PVC cylinder to manufacture a concrete bridge pier (12), wherein the bottom surface depth of the PVC cylinder is 600 mm and the top surface height is 150 mm. The soil layer (13) is drained and consolidated, and a loading steel plate (11) is placed on the upper surface of the soil layer (13). The loading steel plate (11) is 10 mm thick and weighs 150 kg, so that the soil layer (13) is compacted and free water is discharged through the drainage hole (10). Instrument layout, the enclosure of the detachable model box (8) is removed, and when the strength of the rock layer (14) reaches 75% of the design strength, a broadband detector (7) is laid out in the rock layer (14) of the pier-foundation coupling model. After the soil layer (13) is drained and consolidated, a broadband detector is laid out in the soil layer (13) of the pier-foundation coupling model. Vibration and signal collection: the controller (2) controls the motor switch (3) through the host (1), so that the variable frequency vibration motor (4) on the top of the concrete pier (12) starts to run in sequence at intervals of 0.6 seconds. At the same time, the near-field high-speed rail seismic signal is received and stored in sequence through the broadband detector (7), data concentrator (6), converter (5) and host (1) in the signal collection subsystem.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have many substitutions and changes. Any modification, substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0043] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A test system for studying near-field high-speed rail seismic signals, characterized in that: include: A removable model box, supported by a rigid base, for loading the pier-foundation coupling model; The pier-foundation coupling model has a soil layer on the upper layer and a rock layer on the lower layer, which is used to simulate the near-field environment of the high-speed railway. The soil drainage and consolidation subsystem applies a load to the soil layer by loading a steel plate to drain and consolidate the soil layer, and the free water is discharged through the drainage holes, which is used to simulate the reinforcement of the high-speed railway foundation. The vibration generating subsystem generates vibrations through the host, controller, motor switch and variable frequency vibration motor to simulate the moving high-speed railway passing through the top of the bridge pier as the earthquake source; the signal acquisition subsystem receives and stores the near-field high-speed railway seismic signals through the broadband detector, converter, data concentrator and host; The test method of the test system includes the following steps: Step 1: Design the experimental plan. Establish a reasonable mapping relationship between the model scale and the engineering scale, determine the spacing, bottom depth and top height of the model piers according to the actual high-speed rail parameters and the pier spacing, design the simulated high-speed rail train speed, determine the vibration time interval of each vibration motor, and design the size of the pier-foundation coupling model; Step 2: Create a coupling model. Arrange the rigid base and the bottom plate of the detachable model box in the concrete curing environment, assemble the detachable model box enclosure and fix it with long rod screws, arrange the foundation in the detachable model box, first arrange the lower rock layer, wait for the rock layer to solidify and the strength reaches 75% of the design strength, arrange the upper soil layer, and use the PVC cylinder to pour concrete to make the bridge pier. The position of the bottom and top surfaces of the PVC cylinder is determined according to the designed test plan; Step 3: Soil drainage and consolidation, Place a loading steel plate on the upper surface of the soil layer to compact the soil layer and allow free water to drain through drainage holes; Step 4: Instrument layout, Remove the panels of the detachable model box and place broadband geophones in the rock and soil layers of the pier-foundation coupling model; Step 5: Oscillation and signal acquisition, The controller controls the motor switch through the host, so that the variable frequency vibration motors on the top of the pier start running in sequence. The starting running time and interval of each variable frequency vibration motor depend on the simulated high-speed train speed. Finally, the near-field high-speed rail seismic signal is received and stored through the signal acquisition subsystem.

2. A test system for studying near-field high-speed rail seismic signals as claimed in claim 1, characterized in that: The side surface of the detachable model box is provided with protrusions, grooves and screw holes for assembling and fixing the detachable model box.

3. The test system for studying near-field high-speed rail seismic signals according to claim 1, characterized in that: The broadband detector is arranged in the rock layer before it is completely solidified and the strength reaches 75% of the design strength. The broadband detector is arranged in the soil layer after the soil layer is drained and consolidated.

4. The test system for studying near-field high-speed rail seismic signals according to claim 1, characterized in that: The thickness of the loading steel plate is in the range of 10-30 mm, and the weight is in the range of 150-470 kg, so that the soil layer has sufficient density after drainage and consolidation.

5. The test system for studying near-field high-speed rail seismic signals according to claim 1, characterized in that: The rigid base is in the shape of a rectangular ring with a height ranging from 30 to 80 mm and a hollow in the middle so as to reduce the influence of seismic wave reflection on seismic signal reception.

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