Construction method for detecting earth surface directional grouting curtain range through radio wave method

Abstract

The invention discloses a construction method for detecting an earth surface directional grouting curtain range by an electric wave method, which comprises the following steps: step (1), after grouting holes are formed, a signal transmitting end and a signal receiving end of an electric wave detection instrument are respectively lowered to horizontal grouting sections of the grouting holes, and electric wave data information between the two different grouting holes is acquired; (2) electric wave data information of a horizontal grouting section between any two grouting holes in all the grouting holes is collected; (3) after grouting reinforcement, all the grouting holes are swept open, and the steps are repeated to obtain electric wave data information of a horizontal grouting section between any two grouting holes; and (4) comparing the difference of the electric wave data information collected before and after grouting reinforcement, and evaluating the grouting effect. The method is suitable for evaluating the field deep hole grouting curtain range, and can solve the problems that an existing detection method has inadaptability in ground pre-grouting effect evaluation and cannot well meet engineering requirements.

Description

Technical Field

[0001] This invention relates to the field of grouting curtain quality inspection technology. Specifically, it is a construction method for detecting the range of directional grouting curtains on the ground surface using electromagnetic wave methods. Background Technology

[0002] With the vigorous development of water conservancy construction in my country, the geological conditions encountered are becoming increasingly complex. Deeply buried tunnels often encounter fault fracture zones characterized by their great depth and width, posing risks of large deformation of the surrounding rock and water / mud inrush. Surface pre-grouting, as an important method of water-blocking and reinforcement, is highly applicable in the treatment of deep-buried tunnels. However, current methods for detecting the grouting curtain in surface pre-grouting projects are not yet perfect. Due to limitations in existing detection technologies and accuracy, it is difficult to accurately determine the extent of the grouting curtain after grouting, lacking guidance for evaluating the grouting effect. Therefore, it is urgent to find feasible detection technologies based on existing detection methods and by improving construction methods to provide a basis for judging the grouting curtain.

[0003] Patent CN118601580A discloses a method for curtain grouting reinforcement and effect evaluation of tunnel groups in deep backfill areas, mainly used in shallow buried strata. Patent CN114320308A discloses a design and grouting process for vertical shaft grouting under deep asymmetric stress conditions, mainly applied to vertical shaft straight hole grouting. Patent CN108802828A discloses a method for quality inspection of borehole curtains, mainly used in straight hole sections of dam and mine grouting, where holes are drilled around the curtain ring to evaluate the quality of the grouting curtain. For surface pre-grouting projects, drilling holes outside the curtain ring in deep buried strata requires as much time and effort as drilling a new grouting hole; therefore, existing grouting curtain inspection methods are not applicable. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide a construction method for detecting the range of directional grouting curtain on the ground using the radio wave method. This method is applicable to the evaluation of the range of deep hole grouting curtain on site and can solve the problem that existing detection methods are not suitable for evaluating the effect of ground pre-grouting and cannot well serve the needs of engineering projects.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A construction method for detecting the range of directional grouting curtain on the ground surface using radio wave method includes the following steps: Step (1): After the grouting holes are formed, the signal transmitter and signal receiver of the electromagnetic wave detection instrument are lowered to the horizontal grouting sections of two different grouting holes respectively. The electromagnetic wave data between the two different grouting holes is collected by moving the relative positions of the signal transmitter and signal receiver. Compared with magnetic signals, electromagnetic waves have a longer propagation distance and stronger anti-interference ability, so the stratigraphic feature information obtained by this method is more accurate. Step (2): By sequentially transferring the signal transmitter and signal receiver to other different grouting holes, collect the radio wave data information of the horizontal grouting section between any two grouting holes in all grouting holes; Step (3): After grouting reinforcement, sweep open all the grouting holes and repeat steps (1) and (2) to obtain the electromagnetic wave data information of the horizontal grouting section between any two grouting holes in all the grouting holes. Step (4): Compare the differences in the radio wave data collected before and after grouting reinforcement, evaluate the grouting effect based on the comparison results, and determine the effective grouting curtain range for surface directional grouting.

[0006] The above-mentioned construction method for detecting the scope of directional grouting curtain on the ground surface using the radio wave method, in step (1), the operation method for collecting radio wave data information between two different grouting holes is as follows: Step (1-1): After the grouting holes are formed, the horizontal grouting sections of all grouting holes are divided into N observation points, and the distance between any two adjacent observation points is less than or equal to 5m, so as to ensure that complete radio wave data information of the horizontal grouting section is obtained. Steps (1-2): Lower the signal transmitter and signal receiver to the target observation points of the first grouting hole and the second grouting hole respectively to collect data; the target observation points of the first grouting hole and the second grouting hole are located corresponding to each other. Steps (1-3): After the data acquisition of the target observation point is completed, the signal transmitter and signal receiver are moved synchronously and parallel to the next observation point in the horizontal section of the grouting hole, and the data acquisition continues until the data acquisition of N observation points between the first grouting hole and the second grouting hole is completed.

[0007] In the above-mentioned construction method for detecting the directional grouting curtain range of the ground surface using the radio wave method, in step (2), assuming the number of grouting holes is M, the operation method for collecting radio wave data information of the horizontal grouting section between any two grouting holes is as follows: Step (2-1): Lower the signal transmitter and signal receiver to the first grouting hole and the second grouting hole respectively, and collect the radio wave data information between the first grouting hole and the second grouting hole; Step (2-2): Transfer the signal receiving end sequentially to the third grouting hole to the Mth grouting hole, and sequentially collect the radio wave data information between the first grouting hole and the third grouting hole to the Mth grouting hole; Step (2-3): Transfer the signal transmitting end to the second grouting hole and the signal receiving end to the third grouting hole to the Mth grouting hole, and collect the radio wave data information between the second grouting hole and the third grouting hole to the Mth grouting hole; Step (2-4): Transfer the signal transmitter sequentially to the third grouting hole to the Mth grouting hole, and repeat step (2-3) until the radio wave data information between any two grouting holes is collected.

[0008] The above-mentioned method for detecting the construction range of directional grouting curtain on the ground surface using the radio wave method evaluates the grouting effect as follows: compare the differences in radio wave data before and after grouting in each observation interval, and calculate the amplification value of the radio wave signal; the amplification value of the radio wave signal along the straight-line distance between two grouting holes represents the grouting reinforcement effect between the two grouting holes; if the amplification value is higher, the grouting reinforcement effect is better; if the amplification value between the two grouting holes is significantly smaller, the grouting effect between the two grouting holes is poor.

[0009] The above-mentioned construction method for detecting the scope of surface directional grouting curtain using the radio wave method determines the scope of the surface directional grouting curtain based on the comparison results. A closed curve is plotted by connecting the amplification values ​​of different grouting holes. The closed curves plotted with the same amplification value represent the effective grouting curtain. An effective grouting curtain refers to the formation of a complete and closed grouting ring between the grouting holes after grouting, meaning continuous grout diffusion between two grouting holes. The radio wave signal will show a significant amplification after grouting. Since the surrounding rock in different areas is heterogeneous, the amplification value of the radio wave is used to evaluate the grouting curtain scope. The same amplification value indicates that the reinforcement effect is basically consistent. If the amplification value between the two nearest grouting holes differs significantly from that of other grouting holes, it indicates poor grout diffusion in that area, resulting in a poor quality of the effective grouting curtain, failing to form a curtain within the closed grouting hole ring.

[0010] The above-mentioned construction method for detecting the scope of directional grouting curtain on the ground using radio wave method requires a radio wave data acquisition time of 1-2 hours between the signal transmitting end and the signal receiving end.

[0011] In the above-mentioned construction method for detecting the scope of directional grouting curtain on the ground using the radio wave method, the signal transmitter and the signal receiver are connected to different drill rods, and the drill rods are lowered to the target position of the grouting hole.

[0012] The above-mentioned construction method for detecting the scope of directional grouting curtain on the ground using radio wave method has both the signal transmitting end and the signal receiving end as storage type capable of storing data in real time.

[0013] The technical solution of the present invention achieves the following beneficial technical effects: 1. The present invention relates to a construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method. This method is for pre-grouting projects on the ground surface of deep-buried tunnels (caves). After grouting is completed, the range of the grouting curtain is detected using the radio wave method to identify the formation range of the grouting curtain and determine whether an effective grouting curtain has been formed. This facilitates the analysis of the grouting reinforcement effect around the deep-buried tunnel and provides guidance for grouting effect evaluation and subsequent construction.

[0014] 2. The present invention provides a construction method for detecting the scope of directional grouting curtains on the surface using the radio wave method. By optimizing the radio wave method test, it is applicable to the evaluation of the scope of deep-hole grouting curtains in the field. By utilizing existing grouting holes in the ground pre-grouting project for stratum exploration and grouting effect analysis, it can quantitatively reveal the reinforcement effect of the surrounding rock after grouting and the formation range of the grouting curtain within the envelope of the grouting hole. At the same time, it can also indirectly analyze the changes in the mechanical properties of the surrounding rock after grouting, providing relevant technical means for subsequent grouting quality testing and surrounding rock support design.

[0015] 3. The construction method for detecting the scope of surface directional grouting curtain using the radio wave method of this invention can quickly provide guidance for surface pre-grouting construction. It allows for rapid evaluation of the grouting curtain near the axis of the excavation face before tunnel or roadway excavation reaches the working face, solving the current problem of insufficient grouting curtain evaluation methods and providing parameter basis for surface pre-grouting quality control. Simultaneously, by comparing the differences in monitoring data before and after grouting, this method can quantify relevant geological parameters, providing a basis for subsequent working face support design. Attached Figure Description

[0016] Figure 1 A schematic diagram of the cross-sectional view of the grouting curtain detection range in an embodiment of the present invention using the radio wave method; Figure 2 A schematic diagram of the electromagnetic wave detection range between two grouting holes in an embodiment of the present invention; Figure 3 A schematic diagram of wave detection in an embodiment of the present invention (the detection range is formed by using one grouting hole as the signal transmitting end and the remaining grouting holes as the signal receiving ends). Figure 4 A schematic diagram of the radio wave detection method for tunnel axis in this embodiment of the invention (with the remaining holes as signal transmitting ends and the corresponding grouting holes as signal receiving ends, forming the grouting detection range). Figure 5 A schematic diagram of the range of grouting curtain detection using the radio wave method along the tunnel axis in this embodiment of the invention.

[0017] The reference numerals in the figure are: 1-grouting hole; 2-tunnel; 3-grout diffusion range. Detailed Implementation

[0018] The construction method for detecting the scope of directional grouting curtain on the ground surface using the radio wave method in this embodiment includes the following steps: Step (1), as follows Figure 1 As shown, after the grouting holes are formed, the signal transmitter and receiver of the electromagnetic wave detection instrument are lowered to the horizontal grouting sections of two different grouting holes, respectively. Electron wave data between the two different grouting holes is collected by moving the relative positions of the signal transmitter and receiver. The specific operation method is as follows: Step (1-1): After the grouting holes are formed, the horizontal grouting sections of all grouting holes are divided into 5 observation points; Steps (1-2), as follows Figure 3 As shown, in this embodiment, there are 6 grouting holes. The signal transmitter and receiver are respectively lowered to the target observation points of the first and second grouting holes for data acquisition. The target observation points of the first and second grouting holes correspond to each other (corresponding means that the line connecting the target observation points of the first and second grouting holes is perpendicular to the tunnel axis). After the grouting holes in the horizontal section are formed, the drill rod and drill bit are pulled out of the borehole. Then, the signal transmitter and receiver are connected to the drill rod. Both the signal transmitter and receiver are storage type and can store data in real time. The signal transmitter and receiver correspond to different boreholes, so they are connected to different drilling rigs. Steps (1-3): After 2 hours of data acquisition at the target observation point (the specific acquisition time can be adjusted based on signal strength and acquisition frequency), the signal transmitter and receiver are moved synchronously and parallelly to the next observation point on the horizontal section of the grouting hole. Data acquisition continues until data acquisition at all 5 observation points between the first and second grouting holes is completed, and the acquired data is exported. At this time, the detection range between the first and second grouting holes detected by the radio wave detection instrument is as follows: Figure 2 As shown.

[0019] Step (2): By sequentially transferring the signal transmitter and receiver to other different grouting holes, collect the electromagnetic wave data information of the horizontal grouting section between any two grouting holes; the specific operation method is as follows: Step (2-1): Lower the signal transmitter and signal receiver to the first grouting hole and the second grouting hole respectively, and collect the radio wave data information between the first grouting hole and the second grouting hole; Step (2-2): The signal receiving end is sequentially moved to the third to sixth grouting holes, and the radio wave data information between the first and sixth grouting holes is collected sequentially. At this time, the detection range obtained after collecting radio wave data information between the first grouting hole and the other five grouting holes is as follows: Figure 3 As shown.

[0020] Step (2-3): Transfer the signal transmitting end to the second grouting hole and the signal receiving end to the third to sixth grouting holes to collect the radio wave data information between the second grouting hole and the third to sixth grouting holes; Step (2-4): Transfer the signal transmitting end sequentially to the third to sixth grouting holes, and repeat step (2-3) until the radio wave data information between any two grouting holes is collected; in this embodiment, there are 6 grouting holes, therefore, a total of 15 sets of radio wave data information are obtained by pairing them up; the detection range obtained after the radio wave data information between any two of the 6 grouting holes has been collected is as follows. Figure 4 As shown. Complete geological information was obtained between all boreholes, depicting the geological conditions within the grouting borehole area.

[0021] Step (3): After grouting reinforcement, sweep open all the grouting holes and repeat steps (1) and (2) at the original observation point to obtain the electromagnetic wave data information of the horizontal grouting section between any two grouting holes in all the grouting holes. Step (4): Compare the differences in radio wave data collected before and after grouting reinforcement, calculate the range of the surface directional grouting curtain based on the comparison results, and evaluate the grouting effect.

[0022] like Figure 5 As shown, based on the collected radio wave signal detection data, the largest circular inner area within the outline connecting the two grouting holes (outside the thick black line) is evaluated. The difference in radio wave signals before and after grouting within this area is used to evaluate the effective grouting curtain range and grouting effect.

[0023] The method for evaluating the grouting effect is as follows: Compare the differences in radio wave data before and after grouting in each observation interval, and calculate the amplification value of the radio wave signal. The amplification value of the radio wave signal along the straight-line distance between two grouting holes represents the grouting reinforcement effect between the two holes. A higher amplification value indicates a better grouting reinforcement effect; a significantly lower amplification value between two grouting holes indicates a poor grouting effect. Taking the same cross-section as an example, plot a closed curve of the amplification values ​​along the line connecting the two closest grouting holes. A higher amplification value between the two grouting holes indicates a better grouting reinforcement effect; a significantly lower amplification value along the straight-line distance between the two grouting holes indicates a poor grouting effect.

[0024] The method for determining the effective grouting curtain range of surface directional grouting based on the comparison results is as follows: Draw a closed curve by plotting the increase values ​​on the line connecting different grouting holes; draw a closed curve for curves with the same increase value, which represents the effective grouting curtain (see...). Figure 5 ).

[0025] This embodiment utilizes pre-grouting holes on the ground. After the grouting holes are formed, radio wave detection instruments are lowered into each hole. Each instrument consists of a transmitter and a receiver. The transmitter is placed in one grouting hole, and the receiver is placed in another. The instruments are moved parallel to each other within the horizontal grouting section of the grouting holes to acquire the signals between them. Then, the relative positions of the instruments are changed to obtain the stratigraphic characteristics within the grouting hole envelope. After grouting reinforcement, the holes are swept, and the receiver and transmitter are placed in different grouting holes again following the same steps to obtain stratigraphic information within the grouting hole envelope area after grouting. This method is applicable to the evaluation of the range of deep-hole grouting curtains in the field. It can quantitatively reveal the reinforcement effect of the surrounding rock after grouting and the formation range of the grouting curtain within the grouting hole envelope. It can also indirectly analyze the changes in the mechanical properties of the surrounding rock after grouting, providing relevant technical means for subsequent grouting quality testing and surrounding rock support design.

[0026] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A construction method for detecting the range of directional grouting curtain on the ground surface using radio wave method, characterized in that, Includes the following steps: Step (1): After the grouting holes are formed, the signal transmitting end and the signal receiving end of the electromagnetic wave detection instrument are lowered to the horizontal grouting sections of two different grouting holes respectively. The electromagnetic wave data information between the two different grouting holes is collected by moving the relative positions of the signal transmitting end and the signal receiving end. Step (2): By sequentially transferring the signal transmitter and signal receiver to other different grouting holes, collect the radio wave data information of the horizontal grouting section between any two grouting holes in all grouting holes; Step (3): After grouting reinforcement, sweep open all the grouting holes and repeat steps (1) and (2) to obtain the electromagnetic wave data information of the horizontal grouting section between any two grouting holes in all the grouting holes. Step (4): Compare the differences in the radio wave data collected before and after grouting reinforcement, evaluate the grouting effect based on the comparison results, and determine the effective grouting curtain range for surface directional grouting.

2. The construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method according to claim 1, characterized in that, In step (1), the operation method for collecting electromagnetic wave data between two different grouting holes is as follows: Step (1-1): After the grouting holes are formed, the horizontal grouting sections of all grouting holes are divided into N observation points, and the distance between any two adjacent observation points is less than or equal to 5m. Steps (1-2): Lower the signal transmitter and signal receiver to the target observation points of the first grouting hole and the second grouting hole respectively to collect data; the target observation points of the first grouting hole and the second grouting hole are located corresponding to each other. Steps (1-3): After the data acquisition of the target observation point is completed, the signal transmitter and signal receiver are moved synchronously and parallel to the next observation point in the horizontal section of the grouting hole, and the data acquisition continues until the data acquisition of N observation points between the first grouting hole and the second grouting hole is completed.

3. The construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method according to claim 1, characterized in that, In step (2), assuming the number of grouting holes is M, the operation method for collecting the electromagnetic wave data information of the horizontal grouting section between any two grouting holes is as follows: Step (2-1): Lower the signal transmitter and signal receiver to the first grouting hole and the second grouting hole respectively, and collect the radio wave data information between the first grouting hole and the second grouting hole; Step (2-2): Transfer the signal receiving end sequentially to the third grouting hole to the Mth grouting hole, and sequentially collect the radio wave data information between the first grouting hole and the third grouting hole to the Mth grouting hole; Step (2-3): Transfer the signal transmitting end to the second grouting hole and the signal receiving end to the third grouting hole to the Mth grouting hole, and collect the radio wave data information between the second grouting hole and the third grouting hole to the Mth grouting hole; Step (2-4): Transfer the signal transmitter sequentially to the third grouting hole to the Mth grouting hole, and repeat step (2-3) until the radio wave data information between any two grouting holes is collected.

4. The construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method according to claim 1, characterized in that, The method for evaluating the grouting effect is as follows: compare the differences in radio wave data before and after grouting in each observation interval, and calculate the amplification value of the radio wave signal; the amplification value of the radio wave signal on the straight distance between two grouting holes represents the grouting reinforcement effect between the two grouting holes; if the amplification value is higher, the grouting reinforcement effect is better, and if the amplification value is smaller, the grouting effect between the two grouting holes is poor.

5. The construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method according to claim 4, characterized in that, The method for determining the scope of the surface directional grouting curtain based on the comparison results is as follows: draw a closed curve by plotting the increase value on the line connecting different grouting holes. The closed curve plotted with the same increase value is the effective grouting curtain.

6. The construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method according to any one of claims 1-5, characterized in that, The radio wave data acquisition time between the signal transmitter and the signal receiver is 1-2 hours.

7. The construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method according to any one of claims 1-5, characterized in that, The signal transmitter and signal receiver are connected to different drill rods and lowered to the target position of the grouting hole via the drill rods.

8. The construction method for detecting the range of directional grouting curtain on the ground surface using the radio wave method according to any one of claims 1-5, characterized in that, Both the signal transmitter and the signal receiver are storage-type devices capable of storing data in real time.

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