Dynamic control method and control system for grouting reinforcement of water-rich layered surrounding rock tunnels

Abstract

A dynamic control method and control system for grouting reinforcement in water-rich layered surrounding rock tunnels includes the following steps: using advanced geological surveys to obtain data on bedding plane orientation, water pressure, fault fracture zones, and the distribution of seepage areas; in layered surrounding rock sections, dividing grouting zones according to bedding dip angles, employing high-pressure fracturing grouting in bedding-parallel zones and permeation grouting in bedding-crossing zones; in fault fracture zones, dividing fault fracture zone grouting zones according to fault width and geological conditions, and using anchor bolts of different depths for grouting; dynamically adjusting the nanocomposite grout mix ratio based on real-time water pressure in each grouting zone; dynamically adjusting grouting pressure and flow rate through an intelligent control system; and evaluating the grouting effect using transient electromagnetic methods and performing secondary grouting for reinforcement. This application enables dynamic control of grouting parameters based on bedding plane conditions during grouting.

Description

Technical Field

[0001] This invention belongs to the technical field of tunnel engineering excavation, and specifically relates to a dynamic control method and control system for grouting reinforcement of water-rich layered surrounding rock tunnels. Background Technology

[0002] In water-rich, fractured, layered rock tunnels, TBM excavation faces significant risks such as rock instability and sudden water inrush. Traditional grouting techniques have shortcomings, such as uncontrollable grout diffusion, excessive grout diffusion along bedding planes due to the anisotropy of layered rock masses, resulting in material waste rates as high as 40%; fixed grouting pressure and flow rates cannot adapt to water pressure fluctuations and dynamic fracture expansion, leading to a water shut-off rate of less than 60%; grouting effect evaluation relies on manual experience, with secondary grouting response cycles exceeding 30 minutes, resulting in low accident prevention efficiency. Existing grouting methods based on permeability coefficient classification have failed to adequately address the impact of bedding planes and dynamic control issues. Summary of the Invention

[0003] This invention provides a dynamic control method and control system for grouting reinforcement of water-rich layered surrounding rock tunnels, which solves the problem that existing grouting methods based on permeability coefficient classification cannot effectively address the influence of bedding planes and dynamic control.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: On the one hand, this application provides a dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels, including the following steps: Step 1: Use advanced geological exploration to obtain data on the attitude of bedding planes, as well as the distribution of water pressure, fault fracture zones, and seepage areas; Step 2: In the layered surrounding rock section, the grouting area is divided according to the dip angle of the bedding. High-pressure fracturing grouting is used in the bedding area, and permeation grouting is used in the bedding area. Step 3: In the fault fracture zone, divide the fault fracture zone into grouting areas according to the width of the fault fracture zone and the strata conditions, and use anchor bolts of different depths for grouting. Step 4: Dynamically adjust the nanocomposite grout ratio based on the real-time water pressure of each grouting area; Step 5: Dynamically adjust the grouting pressure and flow rate through the intelligent control system; Step 6: Evaluate the grouting effect using transient electromagnetic method and perform secondary grouting to achieve reinforcement. Furthermore, in step one, based on the TSP seismic wave reflection method and ground-penetrating radar, the attitude of the bedding plane and the distribution of interlayer water pressure within a range of 50-100m in front of the tunnel face are obtained, as well as data such as the thickness of the fault fracture zone, the longitudinal extension length of the seepage area, and the seepage pressure.

[0005] Furthermore, in step two, grouting is carried out in the conventional area using cement mortar. The grouting pressure in the layered area is 2.5-3MPa, the water-cement ratio of the grout is 0.6:1, and the diffusion radius is ≥3m; the grouting pressure in the layered area is 1.0-1.5MPa, the water-cement ratio of the grout is 0.8:1, and the diffusion radius is ≥5m.

[0006] Furthermore, in step three, based on the width of the fault fracture zone... W f Classify according to geological conditions, and W f Areas <2m deep and filled with clay are defined as Class I strata; W f =2-5m, the area filled with debris is defined as Class II strata; W f Areas with a depth greater than 5m and high water conductivity are defined as Class III strata.

[0007] Furthermore, in step three, the grouting pressure for Class I formations is 1.0-1.5 MPa, and the water-cement ratio of the grout is 0.8:1; the grouting pressure for Class II formations is 1.8-2.5 MPa, and the water-cement ratio of the grout is 0.6:1; for Class III formations, staged grouting is adopted, that is, firstly, ordinary quick-setting grout is injected to block the water inflow channels, the gel time of ordinary quick-setting grout is ≤1 min, and then high-pressure injection of nano-composite grout is carried out, with a grouting pressure ≥2.5 MPa.

[0008] Furthermore, in step four, when 3MPa≥water pressure≥1MPa, a fast-setting nanocomposite slurry is used. The fast-setting nanocomposite slurry includes 40%-50% silicate cement, 5%-8% nano silica, 10%-15% water glass, 0.5%-1% anti-water dispersant, and the remaining component is water.

[0009] Furthermore, in step five, in the layered surrounding rock area, the dynamic adjustment formula for grouting pressure is: ; in, This is the actual grouting pressure. As the reference pressure, For bedding plane density, This represents the maximum permissible bedding density.

[0010] Furthermore, in step five, in the fault fracture zone, based on the width of the fault fracture zone... W f and hydraulic conductivity K f To achieve adjustment of grouting pressure, the dynamic adjustment formula for grouting pressure is as follows: ; in P fFor grouting pressure in the fault fracture zone area, P 0 is the baseline pressure. K f The coefficient of conductivity is 1. W f This represents the width of the fault fracture zone.

[0011] On the other hand, this application provides a dynamic control system for grouting reinforcement of water-rich layered surrounding rock tunnels, used to realize the above-mentioned dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels, including: The geological exploration module is used to detect and identify the attitude of bedding in layered surrounding rocks and the location and width of fault fracture zones. It can generate a three-dimensional model of the distribution of bedding planes and fault fracture zones in front of the tunnel face in real time. The dynamic decision-making module has a built-in database of grouting parameters for different dip angles, water-pressure layered surrounding rock areas and different levels of fault fracture zones. It is used to receive data transmitted by the geological exploration module and output grouting parameters according to the database. The grouting execution module is used to automatically adjust the grouting pressure and reasonable grout ratio and control the on-site grouting according to the zoning design of the layered surrounding rock area and the graded grouting of the fault fracture zone based on the decision parameters. The effect feedback module is used to detect the slurry diffusion range and water blocking rate, and uses 5G wireless transmission to send the test data back to the dynamic decision module in real time. Furthermore, the geological exploration module includes a TSP303 seismograph, a ground-penetrating radar, and a borehole CT scanner; The grouting execution module includes a variable frequency hydraulic pump, a multi-channel flow meter, a dual-liquid grout mixer, and multiple grouting anchors of different lengths; The effect feedback module includes a transient electromagnetic instrument and a piezometer.

[0012] The present invention can achieve the following beneficial effects: 1. This invention solves the problems of uneven grout diffusion and low water blocking rate in traditional technologies by using advanced detection, layered and zoned grouting strategies and dynamic parameter matching. It also achieves minute-level risk response and is suitable for tunnel projects in high water pressure layered surrounding rock. It effectively reduces the probability of sudden water inrush accidents during TBM tunneling and has significant engineering application value.

[0013] 2. This application proposes solutions for various geological conditions in water-rich fractured layered surrounding rock tunnels, including both in-situ and reverse-situ regions of the layered surrounding rock area, as well as various strata in the fault fracture zone. It also proposes grouting parameter adjustment schemes for each type of geological condition, thus realizing the adjustment of grouting parameters under various geological conditions throughout the tunnel.

[0014] 3. By utilizing the grouting reinforcement method and control system of this application, the water blocking rate is increased from the traditional 60% to 92%, and the material cost is reduced by 35%; the uniformity of grout diffusion is improved by 40%, and the thickness of the reinforcement layer is increased by 50%; the response time to sudden water inrush accidents is shortened to less than 3 minutes, the grouting effect is significantly improved, and the response to emergencies is faster, reducing the occurrence of construction accidents. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a process flow diagram of the TBM excavation and grouting reinforcement method for water-rich fractured layered surrounding rock tunnels according to the present invention. Figure 2 This is a schematic diagram illustrating the tunneling effect of the bedding zone strata according to the present invention; Figure 3 This is a schematic diagram illustrating the tunneling effect of the strata in the cutting area according to the present invention; Figure 4 This is a graph showing the compressive strength of the slurry in this invention. Figure 5 This is a diagram illustrating the architecture of the dynamic control system for grouting reinforcement in water-rich layered surrounding rock tunnels according to the present invention.

[0016] The attached diagram lists the components represented by each number as follows: 1. Geological exploration module; 2. Dynamic decision-making module; 3. Grouting execution module; 4. Effect feedback module. Detailed Implementation

[0017] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0018] The geological conditions of a certain water diversion tunnel project are interbedded sandstone and slate with bedding angles of 25°-50° and water pressure of 0.8-1.5MPa. During the tunnel drilling process, there are conventional layered surrounding rock sections and fault fractured sections, and in one section, the water pressure suddenly increases from 1.0MPa to 2.2MPa. This application uses the above-mentioned water diversion tunnel project as an example to illustrate the solution. The method of this invention can solve the problem of grouting during tunneling in sandstone and slate strata.

[0019] A method for grouting reinforcement of TBM tunnels in water-rich fractured layered surrounding rock, referring to Figures 1 to 4 This includes the following steps: Step 1: Advanced geological exploration is employed to obtain data on bedding plane attitude, water pressure, fault fracture zones, and the distribution of seepage areas. Specifically, based on the TSP seismic wave reflection method and ground-penetrating radar, the bedding plane attitude and interlayer water pressure distribution within a range of 50-100m ahead of the tunnel face are acquired. Data on the thickness, longitudinal extension length, and seepage pressure of fault fracture zones and seepage areas are also obtained. The bedding plane attitude includes parameters such as dip angle and strike. In the above embodiment, the bedding dip angle of the tested layered surrounding rock area is 25°-50°, the water pressure is 0.8-1.5MPa, the thickness of the tested fault fracture zone is 3m, and the water pressure is 2MPa.

[0020] Step 2: Layered grouting design for layered surrounding rock areas: Divide the grouting areas according to the bedding dip angle, such as... Figure 1 As shown, regions with a bedding dip angle α ≤ 30° are defined as bedding-parallel regions, which are grouted using high-pressure fracturing grouting. Regions with a bedding dip angle α > 30° are defined as sheared regions, which are grouted using penetrating grouting. Regardless of whether bedding-parallel or sheared regions are grouted, the grouting holes are arranged perpendicular to the bedding plane.

[0021] The layered grouting design specifically includes: grouting in conventional areas using cement mortar, with a grouting pressure of 2.5-3 MPa, a water-cement ratio of 0.6:1, and a diffusion radius of ≥3m in the in-layer areas; and a grouting pressure of 1.0-1.5 MPa, a water-cement ratio of 0.8:1, and a diffusion radius of ≥5m in the cross-layer areas.

[0022] Step 3: Based on the width of the fault fracture zone and the geological conditions, the fault fracture zone is divided into grouting areas, and grouting is performed using anchor bolts of varying depths. Specifically, based on the width of the fault fracture zone... W f The rough geological conditions were classified and classified. W f Areas <2m deep and filled with clay are defined as Class I strata; W f =2-5m, the area filled with debris is defined as Class II strata; W f Areas with a depth greater than 5m and high water conductivity are defined as Class III strata. Grouting anchors of different depths are used for precise positioning and grouting according to the stratum classification.

[0023] Specifically, the grouting pressure for Class I strata is 1.0-1.5 MPa, and the water-cement ratio of the grout is 0.8:1; the grouting pressure for Class II strata is 1.8-2.5 MPa, and the water-cement ratio of the grout is 0.6:1; for Class III strata, staged grouting is adopted, that is, firstly, ordinary quick-setting grout is injected to block the water inflow channels, and the gel time of ordinary quick-setting grout is ≤1 min, and then nano-composite grout is injected under high pressure, with a grouting pressure ≥2.5 MPa.

[0024] Step 4: Adjust the nanocomposite grout ratio dynamically based on the real-time water pressure of each grouting area. Specifically, adjust the grout gel time and compressive strength based on the real-time water pressure monitoring data of different areas. When 3MPa ≥ water pressure ≥ 1MPa, use a fast-setting nanocomposite grout. The fast-setting nanocomposite grout includes 40%-50% silicate cement, 5%-8% nano silica, 10%-15% water glass, 0.5%-1% anti-water dispersant, and the remaining component is water. The gel time of this type of fast-setting nanocomposite grout is ≤3min, and the compressive strength is ≥20MPa.

[0025] Specifically, when grouting the bedding zone, the grouting parameters were adjusted to a grouting pressure of 2.8 MPa, a flow rate of 80 L / min, and a quick-setting nano-composite grout mix of 45% cement, 6% nano-silica, and 12% water glass. When grouting the cross-bedding zone, the grouting parameters were adjusted to a grouting pressure of 1.2 MPa, a flow rate of 100 L / min, and a grout mix of 40% cement, 5% nano-silica, and 10% water glass. The grout strength curve is shown below. Figure 3 As shown.

[0026] Step 5: Dynamically adjust grouting pressure and flow rate through the intelligent control system: The grouting pressure is dynamically adjusted through the intelligent grouting system at the tail of the TBM shield, with an adjustment range of 0.5-3MPa and an adjustment flow rate of 20-100L / min. The grouting pressure is negatively correlated with the bedding density and the flow rate is positively correlated with the fracture aperture.

[0027] In layered surrounding rock areas, the dynamic adjustment formula for grouting pressure is: ; in, This is the actual grouting pressure. As the reference pressure, , where is the bedding plane density (strips / m). The maximum allowable bedding density is set at 10 bedding planes / m.

[0028] In the fault fracture zone region, based on the width of the fault fracture zone W f and hydraulic conductivity K f The formula for dynamically adjusting grouting pressure is:

[0029] in P f For grouting pressure in the fault fracture zone area, P 0 is the baseline pressure. K f The coefficient of conductivity is ρ (m / s). W f The width of the fault fracture zone is in meters (m).

[0030] Step Six: Evaluate and reinforce the grouting effect using transient electromagnetic method: Use transient electromagnetic method to detect the grout diffusion radius, and perform secondary grouting on areas that do not meet the standard until the permeability coefficient of the surrounding rock is ≤1×10⁻⁶. -7 m / s.

[0031] The secondary grouting uses ultrafine cement-water glass dual-liquid grout with a water-cement ratio of 0.5:1, and the grouting pressure is increased to 1.2-1.5 times the initial pressure.

[0032] This application also discloses a dynamic control system for grouting reinforcement during tunnel excavation in water-rich layered surrounding rock, referring to... Figure 5 It includes a geological exploration module 1, a dynamic decision-making module 2, a grouting execution module 3, and an effect feedback module 4.

[0033] The geological exploration module 1 is used to detect and identify the attitude of layered surrounding rock bedding and the location and width of fault fracture zones. It can generate a 3D model of the bedding plane and fault fracture zone distribution in front of the tunnel face in real time. The geological exploration module 1 includes a TSP303 seismograph, a ground-penetrating radar, and a borehole CT scanner. The TSP303 seismograph has a detection depth of 150m and a resolution of 0.5m, and is used to detect and identify the attitude of layered surrounding rock bedding and the location and width of fault fracture zones. The ground-penetrating radar has a frequency of 100MHz-1GHz and 16 channels, and is used to scan the distribution of surrounding rock bedding and fault fracture zone fractures 50m in front of the tunnel face in real time. The borehole CT scanner provides 360° rotating imaging with a resolution of 1mm, and is used to analyze the distribution of interlayer filling and fault fracture zone material.

[0034] The dynamic decision module 2 has a built-in database of grouting parameters for layered surrounding rock areas with different dip angles and water pressures, as well as fault fracture zones of different levels. It outputs grouting parameters based on this database. The dynamic decision module 2 is based on a BP neural network algorithm. Inputs include the bedding density, water pressure, fracture aperture of the layered surrounding rock, and the thickness, water pressure, and hydraulic conductivity of the fault fracture zone. Based on a decision tree model, it inputs the geological exploration parameters and weights for the layered surrounding rock area and the fault fracture zone. Specifically, the dynamic decision module 2 receives real-time data transmitted from the geological exploration module 1, analyzes the received data according to the built-in database, and outputs parameters for various conditions based on the stratigraphic situation: for bedding areas: grouting pressure 2.5-3 MPa, grout water-cement ratio 0.6:1, diffusion radius ≥3m; or for cross-bedding areas: grouting pressure 1.0-1.5 MPa, grout water-cement ratio 0.8:1, diffusion radius ≥5m; or for Class II strata: grouting pressure 1.8-2.5 MPa, grout water-cement ratio 0.6:1, etc.

[0035] Grouting execution module 3 automatically adjusts the grouting pressure and slurry ratio according to the zoning design of the layered surrounding rock area and the graded grouting of the fault fracture zone, thereby controlling the on-site grouting. Grouting execution module 3 includes a variable frequency hydraulic pump, a multi-channel flow meter, a dual-liquid slurry mixer, and multiple grouting anchor bolts of different lengths.

[0036] A variable frequency hydraulic pump is used to adjust the grouting pressure, with a pressure range of 0-10 MPa and a flow rate of 0-200 L / min. A multi-channel flow meter with a range of 0-150 L / min and a pressure resistance of 15 MPa is used to monitor water flow changes in the grouting area in real time. A dual-liquid grout mixer is controlled by a proportional valve, with an adjustable mixing ratio ranging from 0.1 to 1.0. Based on pressure and flow data feedback, it is used to select and adjust the type of injected nano-grout, quick-setting grout, and the injection ratio of each grout in real time. The grouting anchor bolts have a diameter of 20 mm and a length ranging from 5 m to 15 m, with different lengths selected according to different grouting depth requirements. A piezometer with a range of 0-5 MPa is also installed to monitor water pressure changes during the grouting process in real time.

[0037] The effect feedback module 4 is used to detect the slurry diffusion range and water blocking rate, and uses 5G wireless transmission to send the test data back to the dynamic decision module 2 in real time. The effect feedback module 4 includes a transient electromagnetic instrument and a piezometer. The transient electromagnetic instrument and the piezometer are used to detect the slurry diffusion range and water blocking rate. The transient electromagnetic instrument has a transmission frequency of 25Hz-7.5kHz. The piezometer has a range of 0-5MPa and is arranged at a spacing of 2m×2m.

[0038] Using the dynamic control method and control system for grouting reinforcement in water-rich layered surrounding rock tunnels as described in this application, when the water pressure in a certain section suddenly increases from 1.0 MPa to 2.2 MPa, the system automatically switches to quick-setting grout, and the grouting pressure is increased to 2.5 MPa, successfully avoiding water inrush accidents. The response time is 2 minutes and 45 seconds, the water blocking rate is 92%, the grout diffusion uniformity is improved by 40%, and the material cost is reduced by 38%.

[0039] The above description is only a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels, characterized in that, Includes the following steps: Step 1: Use advanced geological exploration to obtain data on the attitude of bedding planes, as well as the distribution of water pressure, fault fracture zones, and seepage areas; Step 2: In the layered surrounding rock section, the grouting area is divided according to the dip angle of the bedding. High-pressure fracturing grouting is used in the bedding area, and permeation grouting is used in the bedding area. Step 3: In the fault fracture zone, divide the fault fracture zone into grouting areas according to the width of the fault fracture zone and the strata conditions, and use anchor bolts of different depths for grouting. Step 4: Dynamically adjust the nanocomposite grout ratio based on the real-time water pressure of each grouting area; Step 5: Dynamically adjust the grouting pressure and flow rate through the intelligent control system: In layered surrounding rock areas, the dynamic adjustment formula for grouting pressure is: ； in, This is the actual grouting pressure. As the reference pressure, For bedding plane density, The maximum allowable bedding density; Based on the width of the fault fracture zone in the fault fracture area W f and hydraulic conductivity K f To achieve adjustment of grouting pressure, the dynamic adjustment formula for grouting pressure is as follows: ； in P f For grouting pressure in the fault fracture zone area, P 0 is the baseline pressure. K f The coefficient of conductivity is 1. W f The width of the fault fracture zone; Step 6: Evaluate the grouting effect using transient electromagnetic method and perform secondary grouting to achieve reinforcement.

2. The dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels according to claim 1, characterized in that: In step one, based on the TSP seismic wave reflection method and ground-penetrating radar, the attitude of the bedding plane and the distribution of interlayer water pressure within a range of 50-100m in front of the tunnel face are obtained, as well as the thickness, longitudinal extension length and seepage pressure data of the fault fracture zone and seepage area.

3. The dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels according to claim 1, characterized in that: In step two, cement mortar is used for grouting in the conventional area. The grouting pressure in the layered area is 2.5-3MPa, the water-cement ratio of the grout is 0.6:1, and the diffusion radius is ≥3m. The grouting pressure in the layered area is 1.0-1.5MPa, the water-cement ratio of the grout is 0.8:1, and the diffusion radius is ≥5m.

4. The dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels according to claim 1, characterized in that: In step three, based on the width of the fault fracture zone... W f Classify according to geological conditions, and W f Areas <2m deep and filled with clay are defined as Class I strata; W f =2-5m, the area filled with debris is defined as Class II strata; Will W f Areas with a depth greater than 5m and high water conductivity are defined as Class III strata.

5. The dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels according to claim 4, characterized in that: In step three, the grouting pressure for Class I formations is 1.0-1.5 MPa, and the water-cement ratio of the grout is 0.8:1; the grouting pressure for Class II formations is 1.8-2.5 MPa, and the water-cement ratio of the grout is 0.6:1; for Class III formations, staged grouting is adopted, that is, ordinary quick-setting grout is first injected to block the water inflow channels, the gel time of ordinary quick-setting grout is ≤1 min, and then nano-composite grout is injected under high pressure, with a grouting pressure ≥2.5 MPa.

6. The dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels according to claim 1, characterized in that: In step four, when the water pressure is ≥1MPa, a fast-setting nanocomposite grout is used. The fast-setting nanocomposite grout includes 40%-50% silicate cement, 5%-8% nano silica, 10%-15% water glass, 0.5%-1% anti-water dispersant, and the remaining component is water.

7. A dynamic control system for grouting reinforcement of water-rich layered surrounding rock tunnels, used to implement the dynamic control method for grouting reinforcement of water-rich layered surrounding rock tunnels as described in any one of claims 1-6, characterized in that, include: The geological exploration module is used to detect and identify the attitude of bedding in layered surrounding rocks and the location and width of fault fracture zones. It can generate a three-dimensional model of the distribution of bedding planes and fault fracture zones in front of the tunnel face in real time. The dynamic decision-making module has a built-in database of grouting parameters for different dip angles, water-pressure layered surrounding rock areas and different levels of fault fracture zones. It is used to receive data transmitted by the geological exploration module and output grouting parameters according to the database. The grouting execution module is used to automatically adjust the grouting pressure and reasonable grout ratio and control the on-site grouting according to the zoning design of the layered surrounding rock area and the graded grouting of the fault fracture zone based on the decision parameters. The effect feedback module is used to detect the slurry diffusion range and water blocking rate, and uses 5G wireless transmission to send the test data back to the dynamic decision module in real time.

8. The dynamic control system for grouting reinforcement of water-rich layered surrounding rock tunnels according to claim 7, characterized in that: The geological exploration module includes a TSP303 seismograph, a ground-penetrating radar, and a borehole CT scanner. The grouting execution module includes a variable frequency hydraulic pump, a multi-channel flow meter, a dual-liquid grout mixer, and multiple grouting anchors of different lengths; The effect feedback module includes a transient electromagnetic instrument and a piezometer.

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