Method for monitoring wet shotcreting of concrete under tunnel steel arch support and scanning device thereof

Abstract

The invention provides a method for monitoring wet spraying of concrete under tunnel steel arch support and a scanning device thereof, and the method comprises the following steps: in a wet spraying machine operation gap, a laser scanning unit axially moves from the position of a positioner to the direction of a tunnel face so as to scan the surface of a tunnel rock wall; acquiring geometric point cloud data of rock walls exposed between adjacent steel arches; taking a continuous three-truss steel arch as a target, and in the mobile scanning process of the laser scanning unit, extracting scanning points of a scanning path of the laser scanning unit, which are tangent to two sides of the middle steel arch and coincide with a rock wall; and splicing and calculating opposite scanning areas on the two sides of the scanning point to obtain rock wall geometric point cloud data of the shielding part of the middle steel arch. According to the method, the geometric point cloud data of the rock wall exposed between the adjacent steel arches are combined, and the complete form data of the surface of the rock wall are accurately obtained by splicing the geometric point cloud data of the rock wall of the shielding part of the steel arches; and interference of splashed concrete materials can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering construction, and in particular to a monitoring method and a scanning device for wet spraying of concrete under tunnel steel arch support. Background Art

[0002] The primary support section refers to a temporary support structure that is quickly applied after tunnel excavation to prevent the surrounding rock from loosening, deforming or collapsing at an early stage. This support measure is intended to maintain the stability of the tunnel section, ensure the safety of construction workers, and provide support for the subsequent permanent support system.

[0003] Wet concrete spraying is a commonly used support method in tunnel engineering. For example, after drilling and blasting, a large amount of concrete needs to be sprayed on the exposed rock surface to form a protective layer to prevent further deterioration of the rock layer. For lower-grade surrounding rocks, steel arches are often required for support before concrete spraying.

[0004] With the advancement of technology and the increasing demand for intelligent tunnel construction, it is necessary to quickly evaluate the actual rebound data of concrete on the wall and the over-excavation data while mechanized tunnel construction is in progress to assist in adjusting the on-site spraying construction process. Due to the obstruction of the steel arch, the scanning data of each cycle will not be the complete morphological data of the rock wall, which causes certain deviations in traditional fixed-point laser scanning and other methods; in addition, the stones splashing at the wet spraying site are also dangerous, and fixed-point scanning equipment is difficult to adapt to this harsh environment.

[0005] It can be seen that how to conduct real-time dynamic monitoring and analysis to accurately obtain the adsorption and bonding conditions of concrete on the tunnel rock wall surface and provide data support for information-based and intelligent tunnel construction control is an urgent problem to be solved. Summary of the invention

[0006] The technical problem to be solved by the present invention is how to obtain complete morphological data of the tunnel rock wall surface to monitor the adsorption and bonding of concrete.

[0007] In order to solve the above technical problems, the present invention provides a monitoring method for wet spraying of concrete under tunnel steel arch support, the method comprising the following steps:

[0008] Obtaining geometric point cloud data of rock walls exposed between adjacent steel arches: During the intervals between the wet spraying machine operations, the laser scanning unit moves axially from the locator position toward the tunnel face to scan the tunnel rock wall surface and obtain geometric point cloud data of rock walls exposed between adjacent steel arches;

[0009] Obtaining geometric point cloud data of the rock wall of the part blocked by the steel arch: taking three consecutive steel arches as the target, during the mobile scanning process of the laser scanning unit, extracting the scanning points where the scanning path of the laser scanning unit is tangent to both sides of the middle steel arch and coincides with the rock wall; splicing and calculating the scanning areas facing each other on both sides of the scanning point, and obtaining the geometric point cloud data of the rock wall of the part blocked by the middle steel arch;

[0010] Obtaining the spraying volume of the wet spraying machine in the current operation cycle: Calculate the spraying volume of the wet spraying machine in the current operation cycle based on the acquired complete geometric data of concrete attached to the rock wall after wet spraying in the current operation cycle.

[0011] Furthermore, before the wet spraying machine is operated, it also includes:

[0012] Arranging a guide rail with a bracket and carrying the laser scanning unit near the tunnel centerline, the guide rail spanning the wet spraying area and the completion area;

[0013] The positioner is arranged at one end of the guide rail away from the wet spraying area;

[0014] An inertial navigation unit and a control computer are arranged in the laser scanning unit to calculate the coordinates of the laser scanning unit moving along the guide rail.

[0015] Furthermore, the step of obtaining the geometric point cloud data of the rock wall of the portion blocked by the steel arch frame further includes:

[0016] Along the moving direction of the laser scanning unit, three consecutive steel arch frames are taken as targets, and are recorded as the first steel arch frame, the second steel arch frame and the third steel arch frame in sequence;

[0017] It is recorded that when the scanning path of the laser scanning unit is tangent to the two sides of the second steel arch frame in sequence and the scanning point coincides with the rock wall, the corresponding positions of the laser scanning unit are the first position and the third position in sequence;

[0018] When the scanning path of the laser scanning unit is tangent to both sides of the second steel arch frame at the same time, the corresponding position of the laser scanning unit is the second position;

[0019] When the laser scanning unit moves to the first position, the rock wall surface that can be scanned is S1; when the laser scanning unit moves to the third position, the rock wall surface that can be scanned is S2; then the rock wall geometric point cloud data of the part blocked by the second steel arch is S1+S2;

[0020] When the laser scanning unit moves to the second position, the geometric point cloud data of the rock wall exposed between the first steel arch frame and the second steel arch frame is S2a;

[0021] When the laser scanning unit moves to the second position, the geometric point cloud data of the rock wall exposed between the second steel arch frame and the third steel arch frame is S2b;

[0022] Then the complete rock wall geometric point cloud data between the first steel arch frame and the third steel arch frame is S2a+S1+S2+S2b.

[0023] Furthermore, the method of obtaining the spraying volume of the wet spraying machine in the current operation cycle also includes:

[0024] Each scanning cycle of the laser scanning unit corresponds to the start S start and end S end Geometric point cloud data of two rock wall surfaces;

[0025] The S start and S end Perform surface fitting processing to obtain the geometric data of concrete attached to the rock wall;

[0026] The actual rebound rate is calculated based on the geometric data of the concrete attached to the rock wall, and the over-excavation and under-excavation are evaluated to guide the next cycle of wet spraying operation of the wet spraying machine.

[0027] A scanning device for wet spraying of concrete under the support of a tunnel steel arch frame, wherein the scanning device is applied to a monitoring method for wet spraying of concrete under the support of a tunnel steel arch frame.

[0028] Furthermore, the scanning device comprises:

[0029] A guide rail is arranged near the center line of the tunnel and spans the wet spraying area and the completion area, and a positioner is also provided at the end of the guide rail in the completion area;

[0030] The laser scanning unit can move axially along the guide rail to scan the surface of the tunnel rock wall.

[0031] Furthermore, an inertial navigation unit and a control computer are provided in the laser scanning unit, wherein the inertial navigation unit can calculate the Y-axis coordinate position of the axial movement of the laser scanning unit to assist in splicing the rock wall geometric point cloud data of the part blocked by the steel arch.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention combines the geometric point cloud data of the rock wall exposed between adjacent steel arch frames and splices the geometric point cloud data of the rock wall blocked by the steel arch frames, so as to accurately obtain the complete morphological data of the rock wall surface and effectively monitor the adsorption and bonding of concrete; at the same time, it can effectively avoid the interference of splashing concrete materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the spatial arrangement of a scanning device disclosed in an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of a scanning device disclosed in an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of the geometric point cloud data analysis process of the rock wall of the steel arch frame shielding part disclosed in the embodiment of the present invention.

[0037] In the figure:

[0038] 00. Rock wall; 01. Steel arch; 10. Guide rail; 11. Positioner; 20. Laser scanning unit; 21. Inertial navigation unit; 22. Control computer. DETAILED DESCRIPTION

[0039] In order to make the technical scheme and technical effect of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0040] The present invention aims to provide a monitoring method for wet spraying of concrete under the support of a tunnel steel arch and a laser scanning device thereof, so as to solve the drawbacks that traditional fixed-point scanning equipment cannot scan the complete morphological data of the rock wall due to the obstruction of the steel arch, and is difficult to adapt to dangerous environments such as splashing stones at the wet spraying site.

[0041] Scanning device for wet spraying of concrete under steel arch support in tunnels:

[0042] refer to Figure 1-2 The scanning device mainly includes a guide rail 10 and a laser scanning unit 20. The steel arch frame 01 supporting the rock wall 00 is a commonly used I-beam welded segmented arch frame in tunnels, and its size is known.

[0043] Specifically, the guide rail 10 is arranged near the center line of the tunnel and crosses the wet spraying area and the completion area, and a positioner 11 is provided at the end of the guide rail 10 in the completion area. The positioner 11 is a limited trigger device, and the positioner 11 is provided in principle so as not to hinder the movement of the wet spraying machine. Preferably, the guide rail 10 is a straight steel rail, which carries and drives the rapid movement of the laser scanning unit 20, and has brackets at both ends for fixing to the ground.

[0044] Specifically, the laser scanning unit 20 can move axially along the guide rail 10 to scan the surface of the tunnel rock wall 00. Preferably, the laser scanning unit 20 uses a laser radar that can scan 360°, for example, DJI MID360. The laser scanning unit 20 is provided with an inertial navigation unit 21 and a control computer 22; wherein the inertial navigation unit 21 is a common integral inertial navigation calculation unit such as IMU, for example, the IMU unit contained in DJI MID360. The inertial navigation unit 21 can calculate the Y-axis coordinate position of the axial movement of the laser scanning unit 20 to assist in splicing the geometric point cloud data of the rock wall 00 blocked by the steel arch frame 01; the control computer 22 is an embedded computer with a certain computing power.

[0045] When the laser scanning unit 20 moves to the locator 11 at the end of the guide rail 10, the locator 11 will send a trigger signal. The control computer 22 receives the trigger signal, indicating that the laser scanning unit 20 has reached a fixed position. At this time, the laser scanning unit 20 is turned off and the calculation is terminated.

[0046] Monitoring method for wet spraying of concrete under tunnel steel arch support:

[0047] The monitoring method for wet spraying of concrete under tunnel steel arch support provided by the present invention is applied to the above-mentioned scanning device.

[0048] refer to Figure 3 , the specific monitoring method includes the following steps:

[0049] Step 1: Arrange the scanning device.

[0050] Before the wet spraying machine starts, a guide rail 10 with a bracket and carrying a laser scanning unit 20 is arranged near the center line of the tunnel, and the guide rail 10 spans the wet spraying area and the completion area; a positioner 11 is arranged at one end of the guide rail 10 away from the wet spraying area;

[0051] An inertial navigation unit 21 and a control computer 22 are arranged in the laser scanning unit 20 to calculate the Y-axis coordinate of the laser scanning unit 20 moving along the guide rail 10 .

[0052] Step 2: Obtain geometric point cloud data of the rock wall 00 exposed between adjacent steel arch frames 01.

[0053] During the intervals between wet spraying machine operations, the laser scanning unit 20 moves axially from the position of the locator 11 toward the tunnel face to scan the surface of the tunnel rock wall 00, and the inertial navigation unit 21 is started to integrate to obtain the geometric point cloud data of the rock wall 00 exposed between adjacent steel arches 01; wherein the tunnel face is located at the deepest end of the guide rail 10. Figure 3 S2a and S2b are the geometric point cloud data of the exposed rock wall 00 scanned by the laser scanning unit 20.

[0054] Step 3: Obtain the geometric point cloud data of the rock wall that is blocked by the steel arch.

[0055] Taking three consecutive steel arch frames as the target, during the mobile scanning process of the laser scanning unit, the scanning points where the scanning path of the laser scanning unit is tangent to both sides of the middle steel arch frame and coincides with the rock wall are extracted; the scanning areas facing each other on both sides of the scanning point are spliced ​​and calculated to obtain the geometric point cloud data of the rock wall of the part blocked by the middle steel arch frame.

[0056] Figure 3 For the illustrated embodiment, along the moving direction of the laser scanning unit 20, three consecutive steel arch frames 01 are taken as targets, and are sequentially recorded as the first steel arch frame, the second steel arch frame, and the third steel arch frame;

[0057] It is noted that when the scanning path of the laser scanning unit 20 is tangent to both sides of the second steel arch frame in sequence and the scanning point coincides with the rock wall, the corresponding positions of the laser scanning unit 220 are the first position and the third position in sequence;

[0058] When the scanning path of the laser scanning unit 20 is tangent to both sides of the second steel arch frame at the same time, the corresponding position of the laser scanning unit is the second position;

[0059] When the laser scanning unit 20 moves to the first position, the rock wall surface that can be scanned is S1;

[0060] When the laser scanning unit 20 moves to the third position, the rock wall surface that can be scanned is S2;

[0061] Then the geometric point cloud data of the rock wall shielded by the second steel arch is S1+S2;

[0062] When the laser scanning unit 20 moves to the second position, the geometric point cloud data of the rock wall exposed between the first steel arch frame and the second steel arch frame is S2a;

[0063] When the laser scanning unit 20 moves to the second position, the geometric point cloud data of the rock wall exposed between the second steel arch frame and the third steel arch frame is S2b;

[0064] The complete rock wall geometric point cloud data between the first steel arch frame and the third steel arch frame are spliced ​​into S2a+S1+S2+S2b.

[0065] Similarly, the rock wall behind each steel arch frame 01 can be completely spliced ​​together, thereby removing the impact of the steel arch frame 01.

[0066] Step 4: Get the spraying volume of the wet spraying machine in the current operation cycle.

[0067] Based on the complete geometric data of concrete attachment to the rock wall after wet spraying in the current operation cycle, the accurate spraying volume of the wet spraying machine in the current operation cycle is calculated.

[0068] Specifically, each scanning cycle of the laser scanning unit 20 corresponds to the start S start and end S end The geometric point cloud data of the two rock wall surfaces; S start and S end All of them are spliced ​​through step 3 and face fitting processing is performed through CloudCompare software to obtain the geometric data of concrete attachment to the rock wall; based on the geometric data of concrete attachment to the rock wall, the actual rebound rate of concrete is calculated and the over-excavation and under-excavation are evaluated to guide the next cycle of wet spraying operation of the wet spraying machine.

[0069] After the laser scanning unit 20 moves to one end of the face of the guide rail 10 , the scanning is finished, and it retreats to one end of the positioner 11 and enters a dormant state.

[0070] During the next wet spraying machine operation interval, return to step 2 and start the next scanning cycle to obtain the geometric data of the concrete attached to the rock wall after each wet spraying.

[0071] On the one hand, the laser scanning unit 20 scans in the gaps between wet spraying operations, effectively avoiding the interference of splashing concrete; on the other hand, during the uninterrupted scanning process, the laser scanning unit 20 can obtain scanning data with the complete shape of the rock wall in each cycle through splicing calculation, even if there is a steel arch obstruction, solving the data deviation problem of traditional fixed-point laser scanning. It can cooperate with mechanized wet spraying applications, guide workers to adjust the concrete formula and spraying on site, and provide basic data support for information-based intelligent tunnel construction control.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A monitoring method for wet spraying of concrete under tunnel steel arch support, characterized in that: The method comprises the following steps: Obtaining geometric point cloud data of rock walls exposed between adjacent steel arches: During the intervals between the wet spraying machine operations, the laser scanning unit moves axially from the locator position toward the tunnel face to scan the tunnel rock wall surface and obtain geometric point cloud data of rock walls exposed between adjacent steel arches; Obtaining geometric point cloud data of the rock wall of the part blocked by the steel arch: taking three consecutive steel arches as the target, during the mobile scanning process of the laser scanning unit, extracting the scanning points where the scanning path of the laser scanning unit is tangent to both sides of the middle steel arch and coincides with the rock wall; splicing and calculating the scanning areas facing each other on both sides of the scanning point, and obtaining the geometric point cloud data of the rock wall of the part blocked by the middle steel arch; Obtaining the spraying volume of the wet spraying machine in the current operation cycle: Calculate the spraying volume of the wet spraying machine in the current operation cycle based on the acquired complete geometric data of concrete attached to the rock wall after wet spraying in the current operation cycle.

2. The monitoring method for wet spraying of concrete under tunnel steel arch support according to claim 1 is characterized in that: Before the wet spraying machine is operated, it also includes: Arranging a guide rail with a bracket and carrying the laser scanning unit near the tunnel centerline, the guide rail spanning the wet spraying area and the completion area; The positioner is arranged at one end of the guide rail away from the wet spraying area; An inertial navigation unit and a control computer are arranged in the laser scanning unit to calculate the coordinates of the laser scanning unit moving along the guide rail.

3. The monitoring method for wet spraying of concrete under tunnel steel arch support according to claim 1 is characterized in that: The step of obtaining the rock wall geometric point cloud data of the portion blocked by the steel arch frame further includes: Along the moving direction of the laser scanning unit, three consecutive steel arch frames are taken as targets, and are recorded as the first steel arch frame, the second steel arch frame and the third steel arch frame in sequence; It is recorded that when the scanning path of the laser scanning unit is tangent to the two sides of the second steel arch frame in sequence and the scanning point coincides with the rock wall, the corresponding positions of the laser scanning unit are the first position and the third position in sequence; When the scanning path of the laser scanning unit is tangent to both sides of the second steel arch frame at the same time, the corresponding position of the laser scanning unit is the second position; When the laser scanning unit moves to the first position, the rock wall surface that can be scanned is S1; When the laser scanning unit moves to the third position, the rock wall surface that can be scanned is S2; Then the rock wall geometric point cloud data of the part blocked by the second steel arch is S1+S2; When the laser scanning unit moves to the second position, the geometric point cloud data of the rock wall exposed between the first steel arch frame and the second steel arch frame is S2a; When the laser scanning unit moves to the second position, the geometric point cloud data of the rock wall exposed between the second steel arch frame and the third steel arch frame is S2b; Then the complete rock wall geometric point cloud data between the first steel arch frame and the third steel arch frame is S2a+S1+S2+S2b.

4. The monitoring method for wet spraying of concrete under tunnel steel arch support according to claim 1 is characterized in that: The method of obtaining the spraying volume of the wet spraying machine in the current operation cycle also includes: Each scanning cycle of the laser scanning unit corresponds to the start S start and end S end Geometric point cloud data of two rock wall surfaces; The S start and S end Perform surface fitting processing to obtain the geometric data of concrete attached to the rock wall; The actual rebound rate of the concrete is calculated based on the geometric data of the concrete attached to the rock wall, and the over-excavation and under-excavation are evaluated to guide the next cycle of wet spraying operation of the wet spraying machine.

5. A scanning device for wet spraying of concrete under the support of a tunnel steel arch, characterized in that: The scanning device is applied to the monitoring method of wet spraying of concrete under tunnel steel arch support as described in any one of claims 1-4.

6. The scanning device for wet spraying of concrete under tunnel steel arch support according to claim 5 is characterized in that: The scanning device comprises: A guide rail is arranged near the center line of the tunnel and spans the wet spraying area and the completion area, and a positioner is also provided at the end of the guide rail in the completion area; The laser scanning unit can move axially along the guide rail to scan the surface of the tunnel rock wall.

7. The scanning device for wet spraying of concrete under tunnel steel arch support according to claim 6 is characterized in that: The laser scanning unit is provided with an inertial navigation unit and a control computer, wherein the inertial navigation unit can calculate the Y-axis coordinate position of the axial movement of the laser scanning unit to assist in splicing the rock wall geometric point cloud data of the part blocked by the steel arch.

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