Tunnel surrounding rock deformation monitoring target device

Abstract

The utility model discloses a tunnel surrounding rock deformation monitoring target device, and relates to the technical field of geotechnical engineering surrounding rock monitoring. The tunnel surrounding rock deformation monitoring target device is characterized in that a plurality of groups of target devices are arranged on surrounding rock of a cavern at equal intervals, each target device comprises a displacement meter, a connection module and a laser scanning target, the displacement meters are buried in the surrounding rock, the connection modules are arranged on the side wall of the surrounding rock and fixedly connected with mounting bases of the displacement meters, and the laser scanning targets are arranged on the mounting bases of the displacement meters. The laser scanning target is installed on the connection module. According to the utility model, surrounding rock internal deformation observation and apparent deformation observation are combined into one, three-dimensional laser scanning point cloud data in different time periods are corrected by using internal displacement monitoring results of the multi-point displacement meter, influence factors of surrounding rock displacement on target positions are considered, and the influence of homonymy point offset on multi-time-period point cloud registration is reduced; the connecting module is adopted as a connecting assembly of the multipoint displacement meter and the reflection target, and the connecting module has the advantages that the structure is simple, and the multipoint displacement meter does not need to be structurally modified.

Description

Technical Field

[0001] The utility model relates to the technical field of surrounding rock monitoring in geotechnical engineering, in particular to a tunnel surrounding rock deformation monitoring target device combined with a multi-point displacement meter. Background Art

[0002] Surrounding rock deformation observation is an essential key project in the excavation and construction process of underground cavern projects. The surrounding rock deformation observation data reflects the surrounding rock properties during the excavation and construction process to a certain extent, and can provide engineers with more detailed dynamic information, which strongly supports the dynamic design of the project, construction organization optimization and engineering safety control.

[0003] At present, the deformation monitoring of surrounding rock during the excavation of underground cavern projects mainly adopts the principle of "overall design and key monitoring". On the one hand, a reasonable monitoring deployment plan is designed considering the overall spatial and temporal distribution; on the other hand, monitoring sections are set up densely for key parts. Surrounding rock deformation observation can be divided into two categories: surface observation and internal observation. At present, surface observation mainly relies on total stations, levels and convergence meters for monitoring, while internal observation mostly uses multi-point displacement meters to monitor the deformation at different depths inside the surrounding rock and determine the range of surrounding rock relaxation and expansion. However, these methods are fixed-point monitoring through a limited number of characteristic sections, which inevitably have blind spots in the monitoring space and cannot well reflect the overall deformation of the surrounding rock of the underground cavern.

[0004] In recent years, 3D laser scanning technology has made great progress in stability, accuracy, and ease of operation, and can fully obtain high-density point cloud data on the surrounding rock surface. In the 3D laser scanning process, it is generally necessary to set up no less than three auxiliary targets or same-name point markers to assist in laser point cloud data splicing, multi-period point cloud registration and other operations. The current process of using 3D laser scanning to observe the deformation of the surrounding rock of underground cavern projects is: first, use 3D laser scanning technology to collect the appearance of the cavern surrounding rock at different times; then, according to the deployed targets or same-name point markers, the cavern surrounding rock point clouds of different periods are registered and compared to calculate and analyze the deformation of the cavern surrounding rock.

[0005] However, fixedly deployed targets or homonymous point markers often shift with the deformation of the surrounding rock. Laser scanning can only obtain surface data of the cavern surrounding rock, and only relies on multi-period underground cavern surrounding rock point cloud data for direct comparison and analysis. Although it can reflect the deformation of the surrounding rock of the underground cavern project, it cannot obtain the true value of the deformation of the cavern surrounding rock, and additional monitoring data must be supplemented. Summary of the invention

[0006] The utility model aims to solve the deficiencies in the prior art and provides a tunnel surrounding rock deformation monitoring target device which collects target offset conditions to assist in correcting surrounding rock deformation calculation values ​​and is combined with a multi-point displacement meter.

[0007] The utility model is a target device for monitoring deformation of tunnel surrounding rock. Multiple groups of target devices are arranged at equal intervals on the surrounding rock of the cavern. The target device is characterized in that it includes a displacement meter, a connection module and a laser scanning target. The displacement meter is buried in the surrounding rock. The connection module is arranged on the side wall of the surrounding rock and is fixedly connected to the mounting base of the displacement meter. The laser scanning target is installed on the connection module, wherein:

[0008] A fixed installation interface is provided on the installation base of the displacement meter, and is fixedly connected to the connection module through the fixed installation interface;

[0009] The connection module includes a shield shell and a tilt sensor. The tilt sensor is installed inside the shield shell. A fixing bolt is provided at one end of the shield shell. The fixing bolt fixes the shield shell on the mounting base through a fixed mounting interface. A mounting bolt is provided at the other end of the shield shell. The laser scanning target is mounted on the end of the shield shell through the mounting bolt. A cable outlet hole is provided on the outer side of the shield shell. The power supply line and the data cable pass through the cable outlet hole.

[0010] The laser scanning target comprises a target base and a reflective target. The target base is fixed on the shield shell by mounting bolts, and the reflective target is mounted on the target base.

[0011] The cable outlet hole of the protective cover shell is equipped with an elastic sealing component, which is used to seal the cable outlet hole after the cable is passed through. Due to the effect of the elastic sealing component, water and fine particles cannot enter the interior of the protective cover shell, thereby protecting the inclination sensor.

[0012] The axis of the inclination sensor is parallel to the axis of the displacement meter, which facilitates the determination of the posture of the axis of the displacement meter drilling installation.

[0013] The reflective target is spherical in shape, which facilitates the fitting of the target's geometric features during laser scanning at different angles.

[0014] When the reflective target is a planar target with a clear reflective center, the reflective target needs to have bidirectional rotation capability, and the reflective center maintains a constant spatial position during the rotation process.

[0015] The working principle of the utility model device is as follows:

[0016] During the excavation and construction of the surrounding rock of the underground cavern, multiple groups of displacement meters are arranged on the monitoring section to observe the internal deformation of the surrounding rock. The utility model is used to jointly arrange a three-dimensional laser scanning reflection target at the installation end of the multi-point displacement meter to perform three-dimensional laser scanning observation of the surrounding rock of the underground cavern at a specific frequency; the observation data is transmitted to the data processing center through a data cable. During the data processing, the laser point cloud data of multiple measuring stations in the same period are spliced ​​with the target as the same-name point; for the point cloud data of the surrounding rock of the underground cavern at different periods, the target displacement value measured by the multi-point displacement meter and the measurement result of the inclination sensor are combined, and the point cloud data are corrected with the point cloud coordinates of the target as a reference, and the point cloud data of the surrounding rock at different periods are further compared and analyzed to calculate a comprehensive analysis of the deformation of the surrounding rock of the underground cavern.

[0017] Compared with the prior art, the utility model has the following characteristics:

[0018] 1. The utility model combines the observation of internal deformation of surrounding rock and the observation of apparent deformation into one, uses the internal displacement monitoring results of the multi-point displacement meter to correct the three-dimensional laser scanning point cloud data of different periods, considers the influence of surrounding rock displacement on the target position, and reduces the influence of the same-name point offset on the multi-period point cloud registration;

[0019] 2. The utility model adopts a connection module as a connection component between the multi-point displacement meter and the reflection target, which has the advantages of simple structure and no need for structural modification of the multi-point displacement meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an overall structural diagram of the laser target device combined with the multi-point displacement meter of the utility model.

[0021] Figure 2 It is a partial enlarged view of the installation base of the displacement meter of the utility model.

[0022] Figure 3 It is a partial enlarged view of the connection module of the utility model.

[0023] Figure 4 It is a schematic cross-sectional diagram of the device arrangement of the utility model.

[0024] In the figure, there are a protective cover shell 1, a tilt sensor 2, a cable outlet hole 3, a reflection target 4, a target base 5, a mounting base 6, a fixing bolt 7, a fixing bolt 8, a mounting bolt 9, and a displacement meter 10. DETAILED DESCRIPTION

[0025] Embodiment 1: A target device for monitoring deformation of surrounding rock of a tunnel, wherein multiple groups of target devices are arranged at equal intervals on the surrounding rock of a cavern, the target device comprises a displacement meter, a connection module and a laser scanning target, the displacement meter is buried in the surrounding rock, the connection module is arranged on the side wall of the surrounding rock and is fixedly connected to the installation base of the displacement meter, the laser scanning target is installed on the connection module, the displacement meter is selected to be able to meet the function of monitoring displacement inside the rock mass and have considerable durability, such as the vibrating string multi-point displacement meter of Nanjing Genan Industrial Co., Ltd.; wherein:

[0026] A fixed installation interface is provided on the installation base of the displacement meter, and is fixedly connected to the connection module through the fixed installation interface;

[0027] The connection module includes a shield shell and a tilt sensor. The tilt sensor is installed inside the shield shell. A fixing bolt is provided at one end of the shield shell. The fixing bolt fixes the shield shell on the mounting base through a fixed mounting interface. The tilt sensor needs to meet the requirements of accuracy and durability, and at the same time needs to be small in size for easy integration, such as the digital output ultra-high precision dual-axis tilt sensor BWS2000 of Beiwei Sensing, or the LoRaWAN tilt sensor and LoRa tilt sensor of Xingzong IoT; a mounting bolt is provided at the other end of the shield shell, and the laser scanning target is installed on the end of the shield shell through the mounting bolt; a cable outlet hole is provided on the outer side of the shield shell, and the power supply line and data cable pass through the cable outlet hole;

[0028] The laser scanning target comprises a target base and a reflective target. The target base is fixed on the shield shell by mounting bolts, and the reflective target is mounted on the target base.

[0029] The cable outlet hole of the protective cover shell is equipped with an elastic sealing component. The elastic sealing component is made of elastic and flexible materials, such as rubber or airbags, and the cable outlet hole is sealed after the cable is passed through. Due to the effect of the elastic sealing component, water and fine particles cannot enter the interior of the protective cover shell, thereby protecting the inclination sensor.

[0030] The axis of the inclination sensor is parallel to the axis of the displacement meter, which is convenient for determining the attitude of the displacement meter drilling installation axis. The reflective target is spherical in shape, which is convenient for fitting the target geometric features during laser scanning at different angles.

[0031] When the reflective target is a planar target with a clear reflective center, the reflective target needs to have bidirectional rotation capability, and the reflective center maintains a constant spatial position during the rotation process.

[0032] During the excavation and construction of the surrounding rock of the underground cavern, multiple groups of displacement meters are arranged on the monitoring section to observe the internal deformation of the surrounding rock. The utility model is used to jointly arrange a three-dimensional laser scanning reflection target at the installation end of the multi-point displacement meter to perform three-dimensional laser scanning observation of the surrounding rock of the underground cavern at a specific frequency; the observation data is transmitted to the data processing center through a data cable. During the data processing, the laser point cloud data of multiple measuring stations in the same period are spliced ​​with the target as the same-name point; for the point cloud data of the surrounding rock of the underground cavern at different periods, the target displacement value measured by the multi-point displacement meter and the measurement result of the inclination sensor are combined, and the point cloud data are corrected with the point cloud coordinates of the target as a reference, and the point cloud data of the surrounding rock at different periods are further compared and analyzed to calculate a comprehensive analysis of the deformation of the surrounding rock of the underground cavern.

Claims

1. A target device for monitoring deformation of surrounding rock in a tunnel, wherein multiple groups of target devices are arranged at equal intervals on the surrounding rock of the cavern, characterized in that The target device includes a displacement meter, a connection module and a laser scanning target. The displacement meter is buried in the surrounding rock. The connection module is arranged on the side wall of the surrounding rock and is fixedly connected to the mounting base of the displacement meter. The laser scanning target is installed on the connection module, wherein: A fixed installation interface is provided on the installation base of the displacement meter, and is fixedly connected to the connection module through the fixed installation interface; The connection module includes a shield shell and a tilt sensor. The tilt sensor is installed inside the shield shell. A fixing bolt is provided at one end of the shield shell. The fixing bolt fixes the shield shell on the mounting base through a fixed mounting interface. A mounting bolt is provided at the other end of the shield shell. The laser scanning target is mounted on the end of the shield shell through the mounting bolt. A cable outlet hole is provided on the outer side of the shield shell. The power supply line and the data cable pass through the cable outlet hole. The laser scanning target comprises a target base and a reflective target. The target base is fixed on the shield shell by mounting bolts, and the reflective target is mounted on the target base.

2. The target device for monitoring deformation of surrounding rock in tunnel according to claim 1, characterized in that The cable outlet hole of the protective cover shell is equipped with an elastic sealing component.

3. The target device for monitoring deformation of surrounding rock in tunnel according to claim 1, characterized in that The axis of the inclination sensor is parallel to the axis of the displacement meter.

4. The target device for monitoring deformation of surrounding rock in tunnel according to claim 1, characterized in that The reflective target is spherical in shape.

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