Method for designing and testing full-section grouting plugging parameters of water-rich tunnel

Abstract

The invention discloses a water-rich tunnel full-section grouting plugging parameter design and test method which comprises the following steps: firstly, establishing a tunnel numerical model by utilizing FLAC3D software according to engineering data, simulating different grouting water plugging ring thicknesses and permeability working conditions based on a fluid-solid coupling numerical simulation method, and analyzing the stability of tunnel surrounding rock; the optimal grouting thickness and grouting permeability characteristics are obtained; secondly, geophysical prospecting is carried out on a full-section grouting section to obtain an electromagnetic rate map around the tunnel, and the actual thickness of a grouting water plugging ring is analyzed; thirdly, a detection hole is drilled in the water plugging ring, the water seepage amount of the water plugging ring is measured, the permeability coefficient of the water plugging ring near the detection hole is inversed through a calculation formula, the analytical relation between the permeability coefficient and the map is established, and the effect of the permeability coefficient of the whole periphery of the grouting section can be analyzed through the map; and obtaining the permeability coefficient and thickness of the actual water plugging ring at the periphery of the tunnel according to the map, comparing the optimal grouting thickness and permeability coefficient scheme obtained by simulation, and guiding the adjustment of the grouting construction process.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and in particular to a method for designing and testing the full-section grouting plugging parameters of a water-rich tunnel. Background Art

[0002] Tunnels (caverns) and underground engineering (collectively referred to as tunnels in this patent for convenience of expression) play an important role in national infrastructure construction. It effectively utilizes the surface space and has a positive impact on transportation and environmental protection. The seepage and gushing water in water-rich tunnels are highly related to construction safety and the underground environment. Therefore, it is very important to select safe and reasonable technical measures for groundwater plugging and disposal. Drainage tunnels discharge the groundwater around the tunnel, effectively controlling the pore water pressure around. However, the long-term discharge of groundwater may cause deterioration or even damage to the groundwater environment, resulting in changes in surrounding rock stress, and finally problems such as surface collapse and tunnel structure damage, which is not conducive to the environmental protection around the tunnel. The water-blocking tunnel controls the pore water pressure around the tunnel by water blocking, and has less impact on the hydrogeological environment around the tunnel, which is conducive to soil and water conservation and more in line with the concept of green development.

[0003] There are various on-site grouting water-blocking technical schemes, including surface grouting, local single-point grouting, curtain grouting, full-section grouting, etc. Among them, full-section grouting has strong applicability, is widely used in different construction environments such as sandy soil, clay, and gravel, and has a significant water-blocking effect in tunnel projects under high water level conditions. At the construction site, the determination of the full-section grouting scheme often lacks certain scientific guidance. Choosing the grouting water-blocking scheme too empirically is likely to cause problems such as material waste and poor water-blocking effect. Therefore, it is necessary to propose a scientific method system for determining some parameters of on-site full-section grouting.

[0004] Currently, the commonly used numerical simulation methods in the field of geotechnical engineering are the finite difference method, the discrete element method, etc., and the commonly used software includes FLAC3D, PFC3D, ABAQUS, etc. The finite difference software FLAC3D uses a continuous grid model and has the following advantages: one is that it can analyze a large engineering numerical model, and the other is that it has high calculation efficiency and is more advantageous for macroscopic mechanical analysis. Therefore, the present invention proposes to use the method of FLAC3D fluid-solid coupling simulation to determine some parameters of tunnel full-section grouting.

[0005] Tunnel geophysical exploration technology belongs to advanced geological prediction and is a technology used to evaluate the geological environment state of tunnels and their surroundings. It mainly obtains geological information inside and around the tunnel through physical exploration means. Commonly used exploration means include acoustic exploration, ground-penetrating radar, electromagnetic method, etc. Applying tunnel geophysical exploration technology to the detection of the full-section grouting water-blocking circle can better analyze the on-site grouting water-blocking effect. However, currently, tunnel geophysical exploration technology and the electromagnetic method have not been effectively combined. Summary of the Invention

[0006] In order to solve the problems in the background technology, the present invention proposes a method for designing and testing the full-section grouting plugging parameters of a water-rich tunnel. This method effectively combines the electromagnetic method with tunnel geophysical exploration technology, improves and combines the grouting water-blocking parameter design and testing technical system of numerical simulation and on-site detection, and provides guarantee for the safe and efficient construction of the full-section grouting of the water-rich tunnel.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A method for designing and testing the full-section grouting plugging parameters of a water-rich tunnel, comprising the following steps:

[0008] S1. According to the on-site survey data, establish a numerical model of the continuous surrounding rock of the tunnel using modeling software, import it into the finite difference software FLAC3D, divide the grouting thickness and the permeability coefficient of the water-blocking circle into multiple working conditions, and then conduct excavation simulations under the fluid-solid coupling conditions of multiple working conditions. After the tunnel is excavated, the pore water pressure around the tunnel hole shows a funnel-shaped distribution;

[0009] S2. Extract the average flow velocity around the tunnel hole in the model, obtain the seepage flow rate around the tunnel excavation hole after grouting according to the seepage flow rate calculation formula Q = S·v, calculate the seepage flow rates under multiple grouting thicknesses and permeability coefficients of the water-blocking circle working conditions and compare them with each other. Considering economy and water-blocking efficiency, obtain the optimal grouting water-blocking permeability coefficient and the optimal thickness of the water-blocking circle;

[0010] S3. Conduct on-site grouting according to the permeability coefficient and thickness scheme of the water-blocking circle determined in step S2. After the slurry solidifies, conduct electromagnetic geophysical exploration and detection along the inside of the full-section grouting water-blocking area of the tunnel to obtain the relationship map of resistivity - and the radial distance from the tunnel inner wall;

[0011] S4. The actual thickness of the water-blocking circle can be obtained through the resistivity - and the radial distance from the tunnel inner wall relationship map. Drill detection holes in the on-site water-blocking circle of the tunnel, with the hole depth being 1 / 2 to 2 / 3 of the thickness of the water-blocking circle, obtain the seepage water volume data in the holes, and then inversely calculate the permeability coefficient of the grouting water-blocking circle near the detection holes through the seepage water volume calculation formula;

[0012] S5. Combine the permeability coefficient of the area near the detection holes of the grouting water-blocking circle obtained with the geophysical exploration map, analyze the analytical relationship between the two, establish an analytical solution, and thus analyze the permeability coefficient of the entire perimeter of the tunnel;

[0013] S6. According to the analytical results in S5, compare the optimal grouting water-blocking permeability coefficient and the optimal thickness of the water-blocking circle obtained by simulation in S2, evaluate the construction effect of the on-site grouting water-blocking circle, and use this as a basis to timely adjust the grouting material and construction technology in the subsequent construction. The optimal adjustment result is that the analytical result in S5 falls within the range of the optimal grouting water-blocking permeability coefficient and the optimal thickness of the water-blocking circle obtained by simulation in S2.

[0014] Preferably, in S1, when modeling, the tunnel grouting water-blocking ring is divided into multiple parts according to different thicknesses; subsequently, when conducting excavation simulation, grouting parameters are assigned to the areas where different water-blocking rings are located for each calculation condition, and different permeability coefficients are assigned to the water-blocking rings.

[0015] Preferably, when extracting the average flow velocity in S2, in the plot operation interface of FLAC3D, click the "+" sign and select to add the data to be displayed in the model, select vectors, and in the newly added vectors drop-down item, select specificdischarge, then the tunnel seepage velocity distribution can be retrieved. Then, by placing the mouse on the arrow at the tunnel wall to view its velocity value, the average seepage velocity v per meter of the tunnel can be obtained, and then according to the seepage flow rate calculation formula Q = S·v, the seepage flow rate around the tunnel excavation after grouting can be obtained.

[0016] In the above formula: Q is the seepage flow rate, or the water discharge in the tunnel, with the unit of m 3 / s; S is the cross-sectional area of the tunnel, with the unit of m 2 ; v is the seepage flow velocity, with the unit of m / s.

[0017] Preferably, when analyzing the resistivity spectrum to obtain the thickness of the water-blocking ring in S4, since the resistivity of the soil in the water-blocking ring increases significantly after grouting, in the resistivity spectrum, the radial length corresponding to the section with a higher resistivity is the actual grouting thickness. When analyzing the relationship between the permeability coefficient and the geophysical prospecting spectrum, it is necessary to establish a corresponding analytical relationship between the resistivity in the electromagnetic geophysical prospecting spectrum and the permeability coefficient of the tunnel full-section grouting water-blocking ring, so that the permeability coefficient of the entire perimeter of the tunnel full-section grouting water-blocking ring can be analyzed according to the spectrum. The analytical relationship expression between the resistivity and the permeability coefficient of the water-blocking ring is:

[0018]

[0019] In the above analytical relationship, k s is the permeability coefficient of the water-blocking ring, in cm / s; m is the resistivity of the electromagnetic geophysical prospecting, in Ω·m.

[0020] Preferably, in S5, by comparing the permeability coefficient of the entire perimeter of the on-site tunnel with the simulation scheme, the adjustment direction of the subsequent construction process is determined, and the grouting material mix ratio and construction process are optimized to make the permeability coefficient of the on-site water-blocking ring fit the simulation scheme in terms of magnitude.

[0021] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0022] A method for designing and testing the full-section grouting sealing parameters of a water-rich tunnel of the present invention uses numerical simulation to pre-analyze the full-section grouting scheme of a water-rich tunnel, avoids material waste caused by over-reliance on experience in construction, and achieves the effect of scientifically formulating a grouting sealing parameter scheme.

[0023] A method for designing and testing the parameters of full-face grouting plugging in a water-rich tunnel combines numerical simulation with on-site inspection, applies theory to practice, and theory and on-site practice complement each other. By inspecting the water-blocking effect of grouting on-site, the construction process is adjusted in a timely manner to approach the optimal plugging parameter scheme.

[0024] A method for designing and testing the parameters of full-face grouting plugging in a water-rich tunnel adopts the methods of electromagnetic tunnel geophysical exploration and drilling detection holes during the process of on-site inspection of the water-blocking effect of the water-blocking ring. The resistivity index of the geophysical exploration map and the water seepage volume in the hole are used as key quantities, and the analytical relationships among the seepage characteristics, thickness, and map of the on-site water-blocking ring are established, giving play to the advantage that the analytical formula can quickly analyze the full-perimeter water-blocking area. This method system of combining multiple technical means such as numerical simulation, tunnel geophysical exploration, and drilling detection in the present invention not only makes the full-face grouting more scientific and efficient, but also provides new ideas and directions for the design of tunnel water-blocking construction plans, promoting the sustainable development of tunnel waterproofing and drainage projects. Brief Description of the Drawings

[0025] Figure 1 It is a flow chart of the method of the present invention.

[0026] Figure 2 It is a distribution diagram of the seepage field after tunnel excavation in the present invention.

[0027] Figure 3 It is a multi-condition division diagram of the model water-blocking ring according to the thickness in the numerical simulation of the present invention.

[0028] Figure 4 It is a regular curve diagram of the tunnel seepage flow rate changing with the permeability coefficient and grouting thickness in the present invention.

[0029] Figure 5 It is a schematic diagram of extracting the seepage velocity in the completed numerical model of the present invention.

[0030] Figure 6 It is an example diagram of electromagnetic tunnel geophysical exploration map in a certain water conveyance project of the present invention. Detailed Description of the Invention

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] Please refer to Figure 1 - Figure 6, the present invention provides a method for designing and testing the full-section grouting plugging parameters of a water-rich tunnel, including:

[0033] S1, according to the on-site survey data, use Rhinocero modeling software to establish a numerical model of the continuous surrounding rock of the tunnel, import it into the finite difference software FLAC3D to carry out excavation simulation under fluid-solid coupling conditions. After the tunnel excavation, the pore water pressure around the tunnel hole is distributed in a funnel shape. (As Figure 2 )

[0034] In the above process, for the accuracy of the simulation results, the tunnel grouting water-blocking ring is divided into multiple parts (such as Figure 3 ) according to different thicknesses during modeling. Subsequently, during the excavation simulation, each calculation condition assigns grouting parameters to the areas where different water-blocking rings are located and assigns different permeability coefficients to the water-blocking rings to realize the simulation of different water-blocking ring thicknesses and different permeability coefficient conditions of the full-section grouting of the water-rich tunnel.

[0035] S2, extract the average flow velocity around the tunnel hole in the model, and obtain the seepage flow rate around the tunnel excavation hole after grouting according to the seepage flow rate calculation formula Q = S·v. Calculate the seepage flow rates under other grouting thicknesses and water-blocking ring permeability coefficient conditions in the same way, and analyze the variation law of the flow rate around the tunnel hole under different water-blocking ring thicknesses and permeability coefficients (such as Figure 4 ) to obtain the optimal grouting water-blocking permeability coefficient and the optimal water-blocking ring thickness.

[0036] For the extraction of the average flow velocity mentioned in step S2, the specific method is: in the plot operation interface of FLAC3D, click the "+" sign and select to add the data to be displayed in the model, select vectors, and select specific discharge in the newly added vectors drop-down item to call out the tunnel seepage velocity distribution. Then, view its velocity value by placing the mouse on the arrow at the tunnel wall (such as Figure 5 ) to obtain the average seepage velocity v per meter of the tunnel.

[0037] For the above calculation formula: Q is the seepage flow rate (the water discharge in the tunnel), m 3 / s; S is the cross-sectional area of the tunnel, m 2 ; v is the seepage flow velocity, m / s.

[0038] S3, carry out on-site grouting according to the water-blocking ring permeability coefficient and thickness scheme determined in step S2. After the slurry solidifies, conduct electromagnetic geophysical exploration on the full-section grouting water-blocking area of the tunnel to obtain the resistivity - radial distance relationship map from the tunnel inner wall (such as Figure 6 )

[0039] This method uses the electromagnetic tunnel geophysical exploration technology to obtain the resistivity changes around the tunnel, which serves as the data basis for analyzing the permeability characteristics and thickness of the tunnel water-blocking ring.

[0040] S4. In the map, the length of the radial distance from the tunnel inner wall corresponding to the section with a higher resistivity is the actual grouting thickness. Drill inspection holes in the on-site water-blocking ring of the tunnel, with the hole depth being 1 / 2 to 2 / 3 of the water-blocking ring thickness, obtain the water seepage volume data in the holes, and then inversely calculate the permeability coefficient of the grouting water-blocking ring near the inspection holes through the water seepage volume calculation formula.

[0041] Regarding what is described in S4: In the map, the length of the radial distance from the tunnel inner wall corresponding to the section with a higher resistivity is the actual grouting thickness. When analyzing the water-blocking ring thickness from the resistivity map, since the resistivity of the soil in the water-blocking ring increases significantly after grouting, in the resistivity map, the radial length corresponding to the section with a higher resistivity is the actual grouting thickness. The hole depth is 1 / 2 to 2 / 3 of the water-blocking ring thickness, aiming not to drill through the water-blocking ring to protect the overall structural integrity of the water-blocking ring and avoid the difficulty of repairing the water-blocking ring due to local damage of the grouting body. There are many water seepage volume calculation formulas, generally including the analytical relationship between the tunnel water discharge and the surrounding rock permeability coefficient. In actual application, attention should be paid to the applicable conditions of each formula. The commonly used water seepage volume calculation formulas are as follows in the table:

[0042] Table 1 Commonly Used Tunnel Water Seepage Volume Calculation Formulas

[0043]

[0044] S5. Combine the permeability coefficient of the area near the inspection holes of the grouting water-blocking ring obtained with the geophysical exploration map, analyze the analytical relationship between the two, establish an analytical solution, and thus analyze the permeability coefficient of the entire perimeter of the tunnel.

[0045] Regarding what is described in S5: Analyze the analytical relationship between the two, establish an analytical solution, and thus analyze the permeability coefficient of the entire perimeter of the tunnel. It means establishing a corresponding analytical relationship between the resistivity in the electromagnetic geophysical exploration map and the permeability coefficient of the full-section grouting water-blocking ring of the tunnel, so that the permeability coefficient of the full perimeter of the full-section grouting water-blocking ring of the tunnel can be analyzed according to the map.

[0046] S6. According to the analytical results in S4, compare the simulated permeability coefficient and thickness scheme, evaluate the construction effect of the on-site grouting water-blocking ring, and use this as a basis to timely adjust the grouting materials and construction technology in the subsequent construction.

[0047] By comparing the magnitude between the on-site tunnel full-perimeter permeability coefficient and the simulated scheme, determine the adjustment direction of the subsequent construction technology, optimize the grouting material mix ratio and construction procedures, etc., so that the on-site water-blocking ring permeability coefficient is in the same order of magnitude as the simulated scheme.

[0048] To more clearly illustrate the specific implementation manners of the present invention, an embodiment is provided below:

[0049] A full-section grouting plugging parameter design and inspection method for a water-rich tunnel of the present invention is as follows in its specific implementation manners:

[0050] S1. Based on a tunnel of a water conveyance project, where the groundwater level is about 65 m above the tunnel, a 50-m water-rich test section is selected as the length of the numerical model, and the overall size of the model is determined to be 100 m × 50 m × 100 m according to the tunnel dimensions. A whole continuous grid model is established using the software Rhinoceros. The grid model is imported into FLAC3D, named and grouped, and a series of numerical simulations under fluid-solid coupling such as applying the water surface (zone water plane), ground stress balance (zone face apply velocity-normal 0), and excavation (zone delete range position 050) are carried out by inputting command stream codes. Table 2 shows the material parameters of the formation and the water-blocking ring.

[0051] Table 2 Mechanical Parameter Table of Surrounding Rock and Water-Blocking Ring

[0052]

[0053] S2. In the plot operation interface of FLAC3D, click the '+' sign and select to add the data to be displayed in the model, select vectors, and select specific discharge in the newly added vectors drop-down item to call out the tunnel seepage velocity distribution. Then, place the mouse on the arrow at the tunnel wall to view its velocity value, so as to obtain the average seepage velocity of the tunnel. According to the seepage flow calculation formula Q = S·v, the seepage flow around the tunnel excavation after grouting is obtained. Calculate the seepage flows under other grouting thicknesses and water-blocking ring permeability coefficients in the same way and fit them into a curve. By analyzing the curve law and considering the water-blocking effect and economic factors, it can be obtained that the thickness of the full-section grouting water-blocking ring for this tunnel project is preferably 2 m, and the permeability coefficient of the water-blocking ring reaches 3.68×10 -7 cm / s to 7.36×10 -7 cm / s is the best.

[0054] S3. Conduct full-face grouting on some sections of the site (referred to as section A for convenience of description). After the grout solidifies, use the high-frequency magnetotelluric sounding (HMT) of the EH4 system inside the tunnel in section A to obtain the relationship spectrum between resistivity and detection distance along the longitudinal direction of section A. After full-face grouting of the tunnel, the resistivity reflected by the grouted body in electromagnetic detection is different from that of the surrounding rock. Therefore, the actual thickness of the water-blocking circle of the tunnel can be obtained according to the mutation of resistivity in the spectrum. Through spectrum analysis, it is found that the minimum grouting thickness of section A is about 1.8 m, which is less than the optimal water-blocking circle thickness of 2 m. Therefore, when conducting full-face grouting in subsequent sections, the construction process should be adjusted in a timely manner to appropriately increase the thickness of the water-blocking circle.

[0055] S4. Drill 3 detection holes for the water-blocking circle inside the tunnel. The diameters of hole No. 1, hole No. 2, and hole No. 3 are 0.2 m, and the hole depths are 0.9 m, 1.0 m, and 1.2 m respectively, all within the range of 1 / 2 to 2 / 3 of the water-blocking circle thickness, that is, 0.9 m to 1.2 m. Obtain the water seepage data in the holes. Considering the geological characteristics of this water conveyance project, use the calculation empirical formula of Yoshi Oshima to back-calculate the permeability coefficient of the grouted water-blocking circle near the detection holes:

[0056]

[0057] In the formula: Q0 is the maximum water seepage volume of the tunnel passing through the water-bearing body, m 3 / s; K is the permeability coefficient of the water-bearing body, m / s; H is the distance from the static water level to the center of the detection hole, m; d is the cross-sectional diameter of the detection hole, m; L is the length of the detection hole passing through the water-bearing body, m.

[0058] After back-calculation, the permeability coefficients of the water-blocking circles near the 3 detection holes in section A are: 5.1×10 -6 cm / s for hole No. 1, 6.3×10 -6 cm / s for hole No. 2, and 2.4×10 -6 cm / s for hole No. 3. The resistivities at the corresponding positions of the three hole positions in the geophysical prospecting spectrum are 410 Ω·m, 430 Ω·m, and 320 Ω·m respectively. Through analysis, the analytical relationship between resistivity and the permeability coefficient of the water-blocking circle is obtained:

[0059]

[0060] In the above analytical relationship, k s is the permeability coefficient of the water-blocking circle, cm / s; m is the resistivity of electromagnetic geophysical prospecting, Ω·m.

[0061] It should be noted that the above analytical relationship is only to more specifically express the idea of this patent and is only applicable to the water conveyance project in this embodiment. Due to different projects and different engineering geological conditions, the obtained analytical relationship is also different, and specific projects need to be analyzed specifically.

[0062] S5. According to the parsing relationship, combined with the map, the seepage coefficient of the water plugging ring in the entire section A is calculated, and the minimum value is 1.03×10 -6 cm / s, while the optimal seepage coefficient of the water plugging ring obtained in step S2 is 3.68×10 -7 cm / s to 7.36×10 -7 cm / s. Therefore, the seepage coefficient of the entire section A is too large, and the mix ratio of the grouting material and the construction process should be adjusted in a timely manner during the subsequent grouting to appropriately reduce the seepage coefficient of the grouting water plugging ring.

[0063] In summary, a design and inspection method for the full-section grouting plugging parameters of a water-rich tunnel in the present invention provides an effective technical system for the design and inspection of the full-section grouting construction of a water-rich tunnel, making the on-site grouting construction plan more scientific and avoiding material waste caused by poor grouting water plugging effect.

[0064] The above description of the present invention and its implementation manners is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual structure is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and design similar structural modes and embodiments without creative work without departing from the purpose of the present invention's creation, they shall fall within the protection scope of the present invention.

Claims

1. A method for designing and testing the full-face grouting plugging parameters of a water-rich tunnel, characterized in that It includes the following steps: S1. According to the on-site survey data, establish a numerical model of the continuous surrounding rock of the tunnel using modeling software, import it into the finite difference software FLAC3D, divide the grouting thickness and the permeability coefficient of the water-blocking ring into multiple working conditions, and then conduct excavation simulations under the fluid-solid coupling conditions of multiple working conditions. After the tunnel excavation, the pore water pressure around the tunnel opening is distributed in a funnel shape. S2. Extract the average flow velocity around the tunnel opening in the model. According to the seepage flow rate calculation formula Q = S·v, obtain the seepage flow rate around the tunnel opening after grouting. Calculate the seepage flow rates under multiple working conditions of grouting thickness and permeability coefficient of the water-blocking ring and compare them with each other. Considering economy and water-blocking efficiency, obtain the optimal grouting water-blocking permeability coefficient and the optimal thickness of the water-blocking ring. S3. Conduct on-site grouting according to the permeability coefficient and thickness scheme of the water-blocking ring determined in step S2. After the grout solidifies, conduct electromagnetic geophysical exploration and detection along the inside of the fully grouted water-blocking area of the tunnel to obtain a resistivity - radial distance relationship map from the tunnel inner wall. S4. Obtain the actual thickness of the water-blocking ring through the resistivity - radial distance relationship map from the tunnel inner wall. Drill detection holes in the on-site water-blocking ring of the tunnel, with the hole depth being 1 / 2 to 2 / 3 of the thickness of the water-blocking ring, obtain the water inflow data in the holes, and then inversely calculate the permeability coefficient of the grouting water-blocking ring near the detection holes through the water inflow calculation formula. S5. Combine the permeability coefficient of the area near the detection holes of the grouting water-blocking ring obtained with the geophysical exploration map, analyze the analytical relationship between the two, establish an analytical solution, and thus analyze the permeability coefficient of the entire perimeter of the tunnel. S6. According to the analytical results in S5, compare the optimal grouting water-blocking permeability coefficient and the optimal thickness of the water-blocking ring obtained from the simulation in S2, evaluate the construction effect of the on-site grouting water-blocking ring, and use this as a basis to timely adjust the grouting materials and construction technology in subsequent construction. It is the optimal adjustment result that the analytical results in S5 fall within the range of the optimal grouting water-blocking permeability coefficient and the optimal thickness of the water-blocking ring obtained from the simulation in S2.

2. The full-section grouting plugging parameter design and inspection method for a water-rich tunnel according to claim 1, characterized in that: In S1, when modeling, divide the grouting water-blocking ring of the tunnel into multiple parts according to different thicknesses; subsequently, when conducting excavation simulations, assign grouting parameters to the areas where different water-blocking rings are located for each calculation working condition, and assign different permeability coefficients to the water-blocking rings.

3. A full-face grouting plugging parameter design and inspection method for water-rich tunnels according to claim 1, characterized in that: When extracting the average flow velocity in S2, on the plot operation interface of FLAC3D, click the "+" sign and select to add the data to be displayed in the model, select vectors, select specificdischarge in the newly added vectors drop-down item, then the tunnel seepage velocity distribution can be displayed. Then, by placing the mouse on the arrow at the tunnel wall to view its velocity value, the average seepage velocity v per meter of the tunnel can be obtained. According to the seepage flow rate calculation formula Q = S·v, obtain the seepage flow rate around the tunnel opening after grouting. In the above formula: Q is the seepage flow rate or the water discharge in the tunnel, with the unit of m 3 / s; S is the area inside the tunnel, with the unit of m 2 ; v is the seepage velocity, with the unit of m / s.

4. A full-face grouting plugging parameter design and inspection method for a water-rich tunnel according to claim 1, characterized in that: When analyzing the resistivity map in S4 to obtain the thickness of the water-blocking ring, since the resistivity of the soil in the water-blocking ring increases significantly after grouting, in the resistivity map, the radial length corresponding to the section with a higher resistivity is the actual grouting thickness; when analyzing the relationship between the permeability coefficient and the geophysical prospecting map in S4, it is necessary to establish a corresponding analytical relationship between the resistivity in the electromagnetic geophysical prospecting map and the permeability coefficient of the tunnel full-section grouting water-blocking ring, so that the permeability coefficient of the entire perimeter of the tunnel full-section grouting water-blocking ring can be analyzed from the map. The analytical relationship expression between the resistivity and the permeability coefficient of the water-blocking ring is as follows: In the above parsing relationship, k s is the permeability coefficient of the water-blocking ring, cm / s; m is the resistivity of the electromagnetic geophysical prospecting, Ω·m.

5. A full-section grouting plugging parameter design and inspection method for a water-rich tunnel according to claim 1, characterized in that: In S5, by comparing the permeability coefficient of the entire perimeter of the on-site tunnel with that of the simulation scheme, the adjustment direction of the subsequent construction process and the optimization of the grouting material mix ratio and construction process are determined, so that the permeability coefficient of the on-site water-blocking ring fits the simulation scheme in terms of magnitude.

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