Deep tunnel or tunnel earth surface directional grouting monitoring method

Abstract

The invention discloses a deep-buried tunnel or tunnel earth surface directional grouting monitoring method which comprises the following steps: S1, arranging signal holes: arranging the signal holes in front of L-shaped grouting holes, and lowering a detection device into a soft and broken stratum in the signal holes; s2, drilling an L-shaped grouting hole; s3, monitoring and collecting stratum information of the fracture zone, wherein the stratum information comprises stratum information in three time periods before grouting, in the grouting process and after grouting; and S4, stratum information data analysis and result output, wherein the monitored grouting diffusion rule is imported into the established geologic model, and the three-dimensional diffusion effect of grouting is visually reflected. According to the invention, the existing signal hole or geological hole can be used for implementation, so that the monitoring cost is reduced; the detection device is arranged on the fractured stratum, construction of grouting holes is not affected, and the change and diffusion rule of the stratum in the real grouting process can be obtained, so that a monitoring method is provided for deep-buried tunnel surface grouting, and an analysis basis is provided for deep-buried grouting technology and grouting mechanism analysis.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rock mass grouting monitoring. Specifically, it is a kind of deep-buried tunnel or tunnel surface directional grouting monitoring method. BACKGROUND

[0002] As a water plugging and stratum reinforcement technology, the advanced surface grouting technology has been applied in more and more projects because it does not interfere with underground construction and can pre-treat the tunnel (hole). However, due to the process characteristics of this advanced grouting reinforcement technology, it is difficult to arrange related monitoring instruments to comprehensively analyze the grouting process, so the grouting reinforcement mechanism and grouting effect analysis are lagging. Most analysis methods are based on the working face of the excavation in the roadway and indoor tests.

[0003] CN202410146491.4 discloses a method and system for monitoring the grouting pressure under the plate. CN202311179475.7 provides a method and device for monitoring the grouting effect of the coal mine ground area. CN202011527120.9 discloses a method, system and device for monitoring the grouting slurry diffusion area in the rock-soil mass. CN202310389628.4 provides a grouting monitoring device for gob area grouting and a gob area grouting method. CN201610035140.1 discloses a grouting diffusion three-dimensional monitoring system and monitoring method. The above-mentioned patents mainly monitor and analyze the grouting reinforcement based on the indoor or working face, and it is difficult to obtain the related data of the deep-buried stratum grouting, especially the slurry diffusion law and reinforcement mechanism of the slurry under different grouting pressures in the deep-buried stratum condition, and there is a lack of real data to guide the progress of the process and the research of the mechanism. In order to accurately reveal the water plugging and reinforcement mechanism and effect of the deep-buried tunnel (hole) surface grouting, it is urgent to propose a grouting monitoring method with high feasibility and accurate data, so as to provide a basis for the research of digital twin technology and grouting mechanism. SUMMARY

[0004] Therefore, the technical problem to be solved by the present application is to provide a deep-buried tunnel or tunnel surface directional grouting monitoring method to solve the problems of lagging effect analysis of grouting, inaccurate grouting monitoring and difficulty in monitoring operation by existing means.

[0005] To solve the above technical problems, the present application provides the following technical solution: a deep-buried tunnel or tunnel surface directional grouting monitoring method, comprising the following steps:

[0006] S1, arranging a signal hole: determining the position of the fracture zone, arranging a signal hole in front of the vertical section of the L-shaped grouting hole along the drilling direction of the deep-buried tunnel or tunnel, and lowering the detection device to the weak and fractured stratum in the signal hole;

[0007] S2, drilling L-shaped grouting hole: drilling and inclining the hole to the soft and broken stratum of the deep buried tunnel or tunnel according to the designed L-shaped grouting hole, lowering the casing for wall protection, and lowering the grout stopper in the casing for grouting;

[0008] S3, monitoring and collecting stratum information of the broken zone: collecting the stratum information of the soft and broken stratum by using the detection device before, during and after grouting in the L-shaped grouting hole;

[0009] S4, data analysis of stratum information and output of results: analyzing the stratum information collected in step S3 to obtain the grouting diffusion range and grouting diffusion speed; introducing the grouting diffusion range and grouting diffusion speed obtained by analysis into the established geological model to obtain a three-dimensional diffusion effect diagram of grouting.

[0010] Preferably, in step S1, when arranging the signal hole, the drill is used to drill vertically into the soft and broken stratum, and the bottom end of the signal hole is located above the horizontal section of the L-shaped grouting hole; the signal hole includes a casing section and a bare hole section from top to bottom; after drilling is completed, the casing is lowered to fix the hole wall, and the detection device is lowered to the bottom of the bare hole section of the signal hole through cable hoisting.

[0011] Preferably, in step S1, the bottom end of the signal hole is located 5-10 m above the horizontal section of the L-shaped grouting hole; the length of the bare hole section of the signal hole is 10-20 m; the 10-20 m long bare hole section facilitates the collected stratum information to be more accurate and true.

[0012] Preferably, in step S1, along the drilling direction of the deep buried tunnel or tunnel: the signal holes are uniformly distributed within the extension range of the soft and broken stratum; the distance between adjacent two signal holes is 50-60 m, and the horizontal distance between the first signal hole in front of the L-shaped grouting hole and the vertical section of the L-shaped grouting hole is 50-100 m.

[0013] Preferably, the detection device is a split type data sensor; the split type data sensor includes a signal transmitter and a signal receiver; the signal transmitter is placed in the signal hole, and the signal receiver is arranged in the L-shaped grouting hole and lowered with the grout stopper to the horizontal section of the L-shaped grouting hole, and the position of the signal receiver is 50-100 m away from the position of the signal transmitter.

[0014] Preferably, the above detection device is an integrated data sensor; the integrated data sensor includes a signal transmission module and a signal receiving module, and the signal transmission module and the signal receiving module are connected through a screw rod and then lowered into the signal hole.

[0015] Preferably, the shell and detection module of the above detection device adopt a corrosion-resistant sealing structure, and shielding measures are taken through a waterproof sealing ring and a corrosion-resistant coating.

[0016] Preferably, in step S3, the collection of stratum information after the end of grouting is continuous data acquisition after stopping grouting from the L-shaped grouting hole until the grouting slurry solidifies and no longer spreads.

[0017] Preferably, in the above step S3, the collected stratum information includes resistivity, voltage, current, frequency and waveform information.

[0018] Preferably, in the above step S4, the method for judging the grouting effect according to the resistivity change in the stratum information is: calculating the resistivity according to the monitored voltage and current, and judging the filling rate of the grouting slurry according to the change rate of the resistivity; the relationship between the change rate of the resistivity and the filling rate of the grouting slurry is:

[0019]

[0020] In the formula, is the change rate of the resistivity; is the resistivity of the water-containing fracture before grouting; is the resistivity of the slurry solidified body; S is the filling rate of the slurry in the fracture;

[0021] The method for judging the grouting effect according to the frequency change in the stratum information is: for the low frequency band of the frequency of the collected stratum information before grouting, which is less than or equal to 100 Hz: sensitive to the pore fluid, the water content in the medium decreases after grouting, and the current amplitude attenuates; find the characteristic frequency band for analysis, and evaluate the grouting effect according to the current attenuation amplitude, the larger the current attenuation amplitude, the better the grouting effect; for the high frequency band of the frequency of the collected stratum information before grouting, which is greater than or equal to 1 kHz: sensitive to the change of the rock mass skeleton, the signal penetration ability is enhanced after grouting and solidification; find the characteristic frequency band for analysis, and evaluate according to the increase amplitude of the resistivity, the larger the increase amplitude of the resistivity, the better the rock mass reinforcement effect.

[0022] The method for judging the grouting effect according to the waveform change in the stratum information is: the higher the waveform distortion rate before grouting, the stronger the non-uniformity of the medium; with the injection of the slurry, the non-uniformity of the medium decreases, the waveform tends to be a sine wave, and the total harmonic distortion decreases; the diffusion radius and the grouting diffusion range of the slurry are quantified by quantifying the decrease amplitude of the total harmonic distortion.

[0023] Since the diffusion speed of the slurry also has differences in different spatial angles in the same position, the application calculates the slurry diffusion speed according to the change range value of the stratum pressure, the grouting pressure and the stratum information. The diffusion speed of the slurry can be approximately obtained through the change of the stratum information. Taking the resistivity as an example: the resistivity of a position before grouting, the resistivity of the position monitored at a certain time during the grouting process has a change of greater than or equal to 20% (may be water displacement, or slurry diffusion to the position), the diffusion speed of the slurry is the ratio of the position to the position of the bottom of the grout plug.

[0024] The technical scheme of the application achieves the following beneficial technical effects:

[0025] 1. The application arranges the detection device in the soft and broken stratum, does not affect the construction of the grouting hole, can obtain the change and diffusion law of the stratum during the real grouting process, solves the problem that the existing analysis method cannot truly reveal the deep-buried tunnel or tunnel grouting reinforcement mechanism, and also provides accurate data for the digital twin technology, and promotes the progress of the deep-buried tunnel or tunnel surface grouting reinforcement technology;

[0026] 2. The application can truly monitor the deep-buried stratum, solves the problem that the grouting monitoring is not accurate and the existing means is difficult to implement operation, thereby providing a monitoring method for the deep-buried tunnel surface grouting, and providing an analysis basis for the deep-buried grouting process and grouting mechanism analysis;

[0027] 3. The application can use the existing geological holes as signal holes for implementation, and does not need to drill new holes or reduce the number of holes to be drilled, thereby further reducing the monitoring cost. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a deep-buried tunnel or tunnel surface directional grouting monitoring flowchart in the embodiment of the application.

[0029] Figure 2 It is a distribution diagram of the L-shaped grouting hole and the signal hole in the embodiment of the application.

[0030] The reference signs in the drawing are as follows: 1-drilling machine; 2-mountain; 3-L-shaped grouting hole; 4-signal hole; 5-detection device; 6-soft and broken stratum; 7-deep-buried tunnel or tunnel. DETAILED DESCRIPTION

[0031] The embodiment is described in combination with the drawings during implementation.

[0032] As shown in the drawing, Figure 1 a deep-buried tunnel or tunnel surface directional grouting monitoring method comprises the following steps:

[0033] S1, arranging a signal hole: first, the position of the fault zone is determined, and generally, the reinforcement area of the fault part is 200 m. The signal hole 4 (an existing geological hole) is arranged 50-100 m in front of the vertical section of the L-shaped grouting hole 3. The drilling machine 1 drills vertically into the soft and broken stratum 6, and the drilling depth is 5-10 m above the horizontal section of the L-shaped grouting hole 3. The signal hole 4 includes a casing section and a bare hole section from top to bottom. The length of the bare hole section of the signal hole 4 is 10-20 m. After drilling is completed, the casing section is lowered to fix the hole wall. The detection device 5 is lowered to the soft and broken stratum 6 in the signal hole 4 through cable hoisting. The final lowering position of the signal detector is the bare hole, which faces the real stratum environment. In this embodiment, the detection device 5 is an integrated data sensor. The integrated data sensor includes a signal transmitting module and a signal receiving module, and the signal transmitting module and the signal receiving module are connected by a screw rod and then lowered to the bottom of the bare hole section of the signal hole 4. The transmitting signal source and the receiving source of the detection device can receive signals within a range of 50-100 m. Although all the grouting ranges cannot be obtained, the grouting diffusion law can be obtained, and then the real grouting process is reflected, and the subsequent grouting reinforcement effect is analyzed.

[0034] The received signal is debugged to obtain the resistivity information within a certain range of the broken zone before grouting. If necessary, the detection device 5 is provided with anti-shielding measures, such as a corrosion-resistant sealing structure of the shell and the detection module, and an anti-shielding measure is taken through a waterproof sealing ring and a corrosion-resistant coating, so that the stability and accuracy of the signal can be effectively ensured. In this embodiment, as shown in FIG. 5, the detection device 5 adopts an integrated data sensor, and the lowering position is the bare hole, which faces the real stratum environment. The monitoring point is closer to the diffusion area, and the monitoring effect is more accurate. This method can monitor the diffusion reinforcement characteristics of the stratum in the whole grouting process, and provides a reliable operation method for the mechanism and effect evaluation of the directional drilling grouting of the deep-buried tunnel stratum. Figure 2

[0035] In other embodiments, if a larger grouting range is required along the drilling direction of the deep-buried tunnel or tunnel 7, a plurality of signal holes are uniformly arranged in the extension range of the soft and broken stratum 6 above the horizontal section of the L-shaped grouting hole 3 in front of the vertical section of the L-shaped grouting hole 3. The distance between two adjacent signal holes 4 is 50-60 m. The distance between the first signal hole 4 in front of the L-shaped grouting hole 3 and the L-shaped grouting hole 3 is 50-100 m, and the diffusion law of the whole section is further monitored.

[0036] In other embodiments, a split data sensor can be used as the detection device 5. The split data sensor includes a signal transmitter and a signal receiver. The signal transmitter is placed in the bottom of the bare hole section of the signal hole 4, and the signal receiver is arranged in the L-shaped grouting hole 3 and lowered in the horizontal section of the L-shaped grouting hole 3 with the grouting plug. The distance between the position of the signal receiver and the position of the signal transmitter is 50-100 m.​

[0037] S2. Drilling L-shaped grouting holes 3: L-shaped grouting holes 3 are formed by drilling L-shaped holes on the ground surface, creating inclined holes to the soft and fractured strata 6 of the deep-buried tunnel or tunnel 7, lowering the casing for wall protection and hole formation, and placing the grout stop plug at the grouting position inside the casing for grouting; if a split-type data sensor is used as a detection device, the signal receiver of the detection device is also arranged in the stratum when the grout stop plug is lowered.

[0038] S3. Monitoring and collection of information on the fractured zone: Grouting is carried out in L-shaped grouting holes 3. At the same time, the grouting diffusion law is monitored, including the formation resistivity, voltage, current, frequency and waveform at three time periods: before grouting, during grouting and after grouting.

[0039] S4. Stratigraphic Information Data Analysis and Result Output: By comparing and analyzing the stratigraphic information at three time periods—before grouting, during grouting, and after grouting—the grouting diffusion range and grouting diffusion rate are obtained, thus revealing the grouting diffusion law. The monitored grouting diffusion law is then imported into the established geological model to intuitively reflect the three-dimensional diffusion effect of grouting, thereby guiding grouting production.

[0040] Taking resistivity as an example, since grouting fills the cracks and reduces resistivity, the resistivity of the surrounding rock within the monitoring range decreases in real time during the grouting process. By comparing the magnitude of the resistivity decrease before and after, the grouting diffusion range and diffusion rate can be determined, thereby revealing the true grouting diffusion law.

[0041] Grouting diffusion law refers to the diffusion space and distance of strata with different lithologies and fracture development levels under different grouting process parameters (pressure, grout type) as grouting time changes. Taking the resistivity of a stratum as an example, the data obtained show the characteristics of stratum resistivity changes at different times. Then, based on the background value of stratum resistivity, the filling effect and spatial distribution characteristics of the grout are obtained.

[0042] The relationship between monitored geological information and grout diffusion:

[0043] 1. Resistivity is calculated by monitoring voltage and current. The core of the grouting diffusion law is to establish the resistivity change rate (…). Quantitative relationship between resistivity change rate and slurry filling rate (S). Relationship between resistivity change rate and filling rate:

[0044]

[0045] in: : Resistivity of water-bearing fractures before grouting (low value); : Resistivity of the solidified slurry (high value, typically >100 Ω·m); S: Filling rate of the slurry in the cracks (0~100%); Elevation of resistivity ∝S. The higher the slurry filling rate, the greater the increase in resistivity.

[0046] 2. Frequency:

[0047] For the low-frequency band (frequency ≤100Hz in the formation information collected before grouting): it is sensitive to pore fluids. After grouting, the water content in the medium decreases and the current amplitude attenuates. The characteristic frequency band is identified and analyzed. The effect is evaluated based on the current attenuation amplitude. The larger the current attenuation amplitude, the better the grouting effect.

[0048] For high-frequency bands (frequency ≥1kHz in the stratigraphic information collected before grouting): these bands are sensitive to changes in the rock mass framework, and the signal penetration ability is enhanced after grouting and solidification. Characteristic frequency bands are identified and analyzed, and the effect is evaluated based on the increase in resistivity; the greater the increase in resistivity, the better the rock mass reinforcement effect.

[0049] 3. Waveform;

[0050] Before grouting, the waveform distortion rate is high and the medium is highly inhomogeneous. As the grout is injected, the inhomogeneity of the medium decreases, the waveform approaches a sine wave, and the total harmonic distortion (THD) decreases. By quantifying the THD reduction, the diffusion radius of the grout can be quantified, thereby obtaining the grout diffusion range.

[0051] Since the diffusion rate of grout varies at different spatial angles within the same location, this invention calculates the grout diffusion rate based on the changes in formation pressure, grouting pressure, and formation information. The grout diffusion rate can be approximated by observing changes in formation information. Taking resistivity as an example: if the resistivity at a certain location before grouting changes by more than or equal to 20% at a certain time during grouting (this could be due to water being squeezed out or grout diffusing to that location), the grout diffusion rate is the ratio of the distance from that location to the bottom grout stop plug to the time elapsed.

[0052] 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 method for monitoring directional grouting on the surface of deeply buried tunnels or tunnels, characterized in that, Includes the following steps: S1. Arrange signal holes (4): Determine the location of the fracture zone, arrange signal holes (4) in front of the vertical section of the L-shaped grouting hole (3) along the drilling direction of the deep-buried tunnel or tunnel (7), and lower the detection device (5) into the weak and fractured stratum (6). S2. Drilling L-shaped grouting holes (3): Drill holes according to the designed L-shaped grouting holes (3) and make inclined holes to the soft and broken strata (6) of the deep buried tunnel or tunnel (7), lower the casing to form the hole for wall protection, and put the grout stop plug at the grouting position in the casing. S3. Monitoring and collection of stratigraphic information of fractured zone: Before grouting, during grouting and after grouting in L-shaped grouting hole (3), stratigraphic information of weak fractured strata (6) is collected by detection device (5); S4. Stratigraphic Information Data Analysis and Result Output: Analyze the stratigraphic information collected in step S3 to obtain the grouting diffusion range and grouting diffusion rate; The grouting diffusion range and grouting diffusion rate obtained from the analysis are imported into the established geological model to obtain a three-dimensional diffusion effect diagram of the grouting.

2. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 1, characterized in that, In step S1, when setting up the signal hole (4), the drilling rig (1) is used to drill vertically into the weak and broken stratum (6). The bottom of the signal hole (4) is located above the horizontal section of the L-shaped grouting hole (3). The signal hole (4) includes a casing section and a bare hole section from top to bottom. After drilling is completed, the casing is lowered to fix the hole wall in the casing section, and the detection device (5) is lowered to the bottom of the bare hole section of the signal hole (4) by cable hoisting.

3. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 2, characterized in that, In step S1, the bottom of the signal hole (4) is located 5 to 10 m above the horizontal section of the L-shaped grouting hole (3); the length of the bare hole section of the signal hole (4) is 10 to 20 m.

4. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 2, characterized in that, In step S1, along the drilling direction of the deep-buried tunnel or tunnel (7): the signal holes (4) are evenly distributed within the extension range of the weak and fractured strata (6); the distance between two adjacent signal holes (4) is 50 to 60 m, and the horizontal distance between the first signal hole (4) in front of the L-shaped grouting hole (3) and the vertical section of the L-shaped grouting hole (3) is 50 to 100 m.

5. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 1, characterized in that, The detection device (5) is a split data sensor; the split data sensor includes a signal transmitter and a signal receiver; the signal transmitter is placed in the signal hole (4), and the signal receiver is arranged in the L-shaped grouting hole (3), and is placed in the horizontal section of the L-shaped grouting hole (3) along with the grout stop plug, and the position of the signal receiver is 50-100m away from the position of the signal transmitter.

6. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 1, characterized in that, The detection device (5) is an integrated data sensor; the integrated data sensor includes a signal transmitting module and a signal receiving module, and the signal transmitting module and the signal receiving module are connected by a screw and then lowered into the signal hole (4).

7. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 1, characterized in that, The outer shell and detection module of the detection device (5) are both made of corrosion-resistant and sealed structure, and are protected by waterproof sealing rings and anti-corrosion coating.

8. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 1, characterized in that, In step S3, after grouting is completed, the collection of formation information is carried out by continuously collecting data after grouting stops at the L-shaped grouting hole (3) until the grout solidifies and no longer diffuses.

9. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 1, characterized in that, In step S3, the collected formation information includes resistivity, voltage, current, frequency, and waveform information.

10. The method for monitoring directional grouting on the surface of deep-buried tunnels or tunnels according to claim 9, characterized in that, In step S4, the method for judging the grouting effect based on the resistivity change in the formation information is as follows: The resistivity is calculated based on the monitored voltage and current, and the filling rate of the grout is determined based on the rate of change of resistivity; the relationship between the rate of change of resistivity and the filling rate of the grout is as follows: ； In the formula, The rate of change of resistivity; The resistivity of the water-bearing fractures before grouting; is the resistivity of the solidified slurry; S is the filling rate of the slurry in the crack. The method for judging the grouting effect based on frequency changes in stratigraphic information is as follows: For the low-frequency band of stratigraphic information collected before grouting (frequency less than or equal to 100Hz): it is sensitive to pore fluids. After grouting, the water content in the medium decreases, and the current amplitude attenuates. The characteristic frequency band is identified and analyzed, and the grouting effect is evaluated based on the current attenuation amplitude. The larger the current attenuation amplitude, the better the grouting effect. For the high-frequency band of stratigraphic information collected before grouting (frequency greater than or equal to 1kHz): it is sensitive to changes in the rock mass skeleton. After grouting solidification, the signal penetration ability is enhanced. The characteristic frequency band is identified and analyzed, and the effect is evaluated based on the increase in resistivity. The larger the increase in resistivity, the better the rock mass reinforcement effect. The method for judging the grouting effect based on waveform changes in formation information is as follows: the higher the waveform distortion rate before grouting, the stronger the inhomogeneity of the medium; as the grout is injected, the inhomogeneity of the medium decreases, the waveform approaches a sine wave, and the total harmonic distortion decreases; the diffusion radius of the grout and the grouting diffusion range are quantified by quantifying the reduction of total harmonic distortion. The grouting diffusion rate is calculated based on the variation values ​​of formation pressure, grouting pressure, and formation information.

Images