A tunnel excavation water inflow evaluation method based on advanced hole drilling high pressure water gushing

Abstract

The application discloses a tunnel excavation water gushing amount evaluation method based on advanced hole exploration high-pressure water gushing, and belongs to the technical field of tunnel water gushing amount calculation. The method comprises the following steps: S1, according to the surrounding rock physical property characteristics displayed by the geophysical seismic wave reflection method, a drilling interval is divided into a plurality of segments to obtain drilling segments; S2, according to the drilling segments, the water yield of each segment is obtained; S3, according to the drilling segments and the water yield of each segment, in combination with the rock mass permeability classification standard, the permeability coefficients of different rock mass structures are preliminarily judged; and S4, in combination with the water head height, the permeability coefficient, the depth of the drilling segment and the equivalent diameter of the tunnel section, the segmented water gushing amount is predicted. The method can integrate and utilize the advanced drilling and geophysical data, predict the tunnel excavation water gushing amount, accurately identify the high water gushing risk segment within a short distance, provide timely and reliable quantitative basis for tunnel construction drainage scheme design, grouting water plugging and risk plan making, and significantly improve the ability of the tunnel construction to cope with water inrush disasters.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction water inflow prediction technology, and in particular to a method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes. Background Technology

[0002] In tunnel engineering, especially in the construction of deep-buried tunnels, underwater tunnels, and tunnels traversing complex geological structures (such as faults and fracture zones), water inrush is one of the main risks. Accurate prediction of water inrush volume is crucial not only for construction safety but also directly impacts drainage design, construction schedule, and project investment. Currently, horizontal boreholes, as one of the most common and direct methods of advanced geological forecasting, are widely used to reveal the geological conditions ahead of the tunnel face. However, in actual construction, there is still a lack of effective and convenient methods for quantitatively assessing the water inrush volume in the unexcavated section ahead using the information revealed by boreholes, particularly high-pressure water inrush information.

[0003] In existing technologies, water inflow prediction largely relies on empirical formulas, numerical simulations, or hydrogeological analogies. Empirical formulas are often overly simplified and have limited applicability; while numerical simulations offer high accuracy, parameter acquisition is difficult and the modeling cycle is long, failing to meet the needs of rapid on-site decision-making; hydrogeological analogies require hydrogeological parameters from similar geological conditions, which are often difficult to obtain in complex mountain tunnels. Especially in high-pressure fracture water sections, the potentially large water inflow after tunnel excavation poses a significant safety threat and increases costs to construction. Therefore, effectively utilizing the advanced horizontal borehole data obtained during construction, particularly the high-pressure water inflow conditions revealed by these boreholes, to establish a rapid and practical method for assessing tunnel excavation water inflow is of great practical significance for guiding on-site construction and controlling the risk of water inrush. Summary of the Invention

[0004] The purpose of this invention is to overcome the problems in the prior art, such as the difficulty in calculating the water volume in the unexcavated section behind the tunnel face and the inability to obtain the corresponding water inflow prediction results in a timely manner based on borehole information. This invention provides a method for evaluating the water inflow in tunnel excavation based on high-pressure water inflow from advanced exploratory boreholes, which is a method for quickly calculating the water volume in the unexcavated section behind the tunnel face during tunnel construction and excavation.

[0005] In a first aspect, the present invention provides a method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes, comprising the following steps:

[0006] S1. Based on the physical characteristics of the surrounding rock shown by the geophysical seismic wave reflection method, the borehole section is divided into several segments to obtain the borehole segments; S2. Obtain the water output during the advanced horizontal drilling process of each section according to the drilling segment; S3. Based on the borehole sections and the water volume in each section, combined with the rock mass permeability classification standard, the permeability coefficient of different rock mass structures is initially determined; S4. Based on the water head height, the permeability coefficient, the depth of the borehole segments, and the equivalent diameter of the tunnel cross-section, predict the segmented water inflow during tunnel excavation.

[0007] Based on the surrounding rock physical properties revealed by geophysical seismic wave reflection, the borehole section is divided into several segments. Anomaly zones in the surrounding rock are accurately identified using geophysical seismic wave reflection, allowing for early prediction of adverse geological structures and preventing geological disasters such as water and mud inrushes, thus ensuring the safety of construction personnel and equipment. Then, the water volume produced during the advanced horizontal drilling process in each segment is obtained. The permeability coefficient is calculated using the rock mass permeability grading standard. Finally, combining the water head height, the permeability coefficient, the depth of the borehole segment, and the equivalent diameter of the tunnel cross-section, the segmented water inflow during tunnel excavation is predicted, converting the small-diameter water inflow observed in the borehole into the predicted water inflow at the tunnel excavation cross-section. This invention combines theoretical basis with field operability, providing construction personnel with crucial early warnings of water inflow risks in a short time.

[0008] Furthermore, before tunnel excavation, if the variation range of water inflow and water pressure in the advanced horizontal exploratory boreholes does not exceed ±30%, the water inflow and water pressure in the advanced horizontal exploratory boreholes should be basically stable, exhibiting a stable flow phenomenon.

[0009] Furthermore, based on the anomalies in the surrounding rock revealed by the geophysical seismic wave reflection method, the surrounding rock structure is segmented. The specific method includes: based on the geophysical anomaly segmentation, the rock mass structure within the borehole length L is divided into n segments: M1, M2, ..., Mn.

[0010] Furthermore, the specific method for obtaining the water volume during the drilling process of the advanced horizontal borehole is as follows: Record the advanced horizontal borehole with a borehole length L. When drilling reaches the geophysical exploration section M1, the depth is... Record the excavation length water volume of section When drilling reached geophysical section M2, the depth was... Record the excavation length water volume of section When drilling reaches the geophysical exploration section Mn at a depth of L, record the excavation length. water volume of section .

[0011] Furthermore, by combining borehole segmentation and rock mass characteristics with case experience, the permeability coefficients of different rock mass structures are preliminarily determined by interpolation through table lookup. The rock mass permeability classification standard includes extremely low permeability, low permeability, weak permeability, moderate permeability, strong permeability, and extremely high permeability levels. Each level is associated with a permeability coefficient range, rock mass characteristics, and borehole water volume.

[0012] Furthermore, the rock mass permeability classification criteria are as follows:

[0013] As a more specific preferred option, the method for initially determining the permeability coefficient is as follows: based on the ratio of the water volume in each section to the water volume revealed by the borehole, the standard permeability coefficient corresponding to the water volume revealed by the borehole is calculated by subtracting it.

[0014] Furthermore, in step S4, the formula for calculating the predicted water inflow volume in each tunnel excavation segment is as follows:

[0015] In the formula, Q represents the inflow rate, measured in cubic meters per second (m³). 3 / h;q n The water volume of the nth segment is expressed in meters (m³). 3 / h;K n L is the permeability coefficient of the nth segment, expressed in m / d. n d is the excavation length (m) of the nth segment; d is the equivalent diameter of the tunnel cross-section (m); H is the water head height (m).

[0016] Furthermore, the method also includes: calculating the total excavation water inflow based on the predicted water inflow of each segment, and forming a prediction table including the borehole segment, the water volume of the borehole segment, the permeability coefficient of the segment, and the predicted excavation water volume, so that on-site technicians can intuitively grasp the distribution and total amount of water inflow, and provide a quantitative basis for drainage capacity configuration.

[0017] Furthermore, the method is particularly suitable for tunnel construction in areas with well-developed high-pressure fissure water, and is used to assess the risks to the inclined shaft reverse slope drainage system after tunnel excavation, and to formulate or adjust drainage plans and emergency response plans accordingly.

[0018] The present invention also provides an electronic device, including at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions that are executed by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described method for evaluating tunnel excavation water inflow based on high-pressure water inflow from advanced exploratory boreholes.

[0019] Compared with the prior art, the beneficial effects of the present invention include: 1. This invention provides a method for assessing water inflow during tunnel excavation based on high-pressure water inflow from pre-exploration boreholes. According to the surrounding rock properties revealed by geophysical seismic wave reflection, the borehole section is divided into several segments. Anomaly zones in the surrounding rock are accurately identified using geophysical seismic wave reflection, allowing for early prediction of adverse geological structures and preventing geological disasters such as water and mud inrushes, thus ensuring the safety of construction personnel and equipment. Then, the water volume produced during the pre-exploration horizontal drilling process in each segment is obtained. The permeability coefficient is calculated using a rock permeability grading standard. Finally, combining the water head height, the permeability coefficient, the depth of the borehole segment, and the equivalent diameter of the tunnel cross-section, the segmented water inflow during tunnel excavation is predicted, converting the small-diameter water inflow observed in the borehole into the predicted water inflow at the tunnel excavation cross-section. This invention's solution balances theoretical basis with field operability, providing construction personnel with crucial early warning of water inflow risks.

[0020] 2. This invention provides a method for assessing tunnel excavation water inflow based on high-pressure water inflow from advanced boreholes. It can quickly predict tunnel excavation water inflow using conventional on-site advanced drilling data, and can especially accurately identify high-risk water inflow sections within a short distance. This provides timely and reliable quantitative basis for tunnel construction drainage scheme design, grouting and water plugging, and risk contingency plan formulation, significantly improving the tunnel construction's ability to cope with water inrush disasters. Attached Figure Description

[0021] Figure 1 The flowchart of the present invention is a method for assessing the water inflow during tunnel excavation based on high-pressure water inflow from advanced exploratory boreholes. Figure 2 The following are field photos of a tunnel face in Embodiment 2 of the present invention: (a) shows the overall situation of the tunnel face, and (b) shows a magnified view of a portion on the right side. Figure 3 This is a field diagram of high-pressure water inrush at the orifice of the advanced horizontal borehole in an embodiment of the present invention. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0023] Example 1 like Figure 1 As shown, a method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes is provided, comprising the following steps: S1. Based on the rock physical properties shown by the geophysical seismic reflection method (TSP), the borehole section is divided into several segments to obtain the borehole segments; The following principles should be followed when interpreting TSP results data: (1) The higher the amplitude of the reflected wave, the greater the difference between the reflection coefficient and the wave impedance.

[0024] (2) If the reflection of the transverse wave S is stronger than that of the longitudinal wave P, it indicates that the rock strata are saturated with groundwater. Care must be taken when comparing any reflection amplitude, as the reflection amplitude is susceptible to random noise and data processing.

[0025] (3) A sudden increase in Vp (longitudinal wave velocity) / Vs (transverse wave velocity) or Poisson's ratio u is caused by the presence of fluid.

[0026] (4) If Vp decreases, it indicates that the crack density or porosity has increased.

[0027] (5) If the Young's modulus increases, the rock strength increases; conversely, the rock strength decreases.

[0028] Based on the anomalies in the surrounding rock revealed by the geophysical seismic wave reflection method, the surrounding rock structure is segmented. The specific method includes: dividing the rock mass structure within the borehole length L into n segments, M1, M2, ..., Mn, according to the geophysical anomaly segmentation.

[0029] Based on the principles and working experience of the TSP method, reflected wave groups that are close to the tunnel axis and have high energy are identified as anomaly zones in the surrounding rock. The classification of these anomaly zones is then based on parameters such as seismic wave velocity, reflected wave phase, Poisson's ratio, and Young's modulus. This classification serves as the basis for borehole segmentation and has direct engineering significance. The specific steps for segmenting the borehole are as follows: Based on the principles and working experience of the TSP method, reflected wave groups that are close to the tunnel axis and have high energy are identified as anomaly zones in the surrounding rock. The types of surrounding rock anomaly zones are classified by comprehensively considering parameters such as seismic wave velocity, reflected wave phase, Poisson's ratio, and Young's modulus; Based on the type and distribution of the abnormal area, the borehole section is divided into several segments, resulting in borehole segments. S2. The water output during the advanced horizontal drilling process of each segment is obtained. Before tunnel excavation, if the variation in water inflow and water pressure in the advanced horizontal exploratory borehole does not exceed ±30%, it is determined that the water flow and water pressure are basically stable and exhibit a stable flow phenomenon, in order to ensure the reliability of subsequent calculation parameters.

[0030] The specific method for obtaining the water volume during advanced horizontal drilling is as follows: Record the length L of the advance horizontal borehole. When drilling reaches the geophysical exploration section M1, the depth is... Record the excavation length water volume of section When drilling reached geophysical section M2, the depth was... Record the excavation length water volume of section When drilling reaches the geophysical exploration section Mn, the depth is... Record the excavation length water volume of section By recording the corresponding water inflow in detail for each segment, the changes in rock mass structure and the location of the water outlet segment can be identified more accurately.

[0031] Record The method for measuring water volume is as follows: collect water in a bucket and then measure the water volume.

[0032] S3. Based on the borehole sections and the water volume in each section, combined with the rock mass permeability classification standard, the permeability coefficient of different rock mass structures is initially determined; Based on the drilling segmentation and rock mass characteristics, permeability coefficients for different rock mass structures are preliminarily determined through table lookup and interpolation. This classification standard includes at least four levels: very low permeability, low permeability, weak permeability, moderate permeability, strong permeability, and very high permeability. Each level is associated with a permeability coefficient range, rock mass characteristics, and the range of water volume revealed in the borehole. The permeability level and permeability coefficient are initially determined based on the water volume revealed in each borehole segment. Specifically, the standard permeability coefficient corresponding to the revealed water volume is calculated by subtracting it from the ratio of the water volume in each segment to the total water volume revealed in the borehole. K n =q n / q 标 K 标， q 标 The amount of water revealed by the borehole is expressed in meters (m). 3 / h, q n The water volume of the nth segment is expressed in meters (m³). 3 / h, Kn is the permeability coefficient of the nth segment, with units of m / d. K 标 This is the standard permeability coefficient, expressed in m / d.

[0033] Refer to Table 1 below and interpolate based on the water output from the borehole.

[0034] Table 1. Rock Mass Permeability Classification Standards

[0035] For example, if a section of the borehole reveals a water volume of 2.7 m... 3 / h, according to the rock mass permeability classification standard, it belongs to weakly permeable (water volume range 1-10 m³ / h). 3 If the permeability coefficient is (2.7 / 10) × 0.0863 = 0.023 m / d, then the recommended permeability coefficient is (2.7 / 10) × 0.0863 = 0.023 m / d; for example, if the borehole reveals a water flow of 15 m³ / h, then the recommended permeability coefficient is (2.7 / 10) × 0.0863 = 0.023 m / d. 3 / h, which is classified as medium permeability (water volume range 10-50 m³ / h).3 If the water volume is / h, then the recommended permeability coefficient is (15 / 50)×8.63 =2.589 m / d. This interpolation method utilizes empirical data from the standard and combines it with actual on-site water volume measurements, improving the objectivity and accuracy of the permeability coefficient value.

[0036] S4. Based on the water head height, the permeability coefficient, and the equivalent diameter of the tunnel cross section, predict the segmented water inflow during tunnel excavation.

[0037] The formula for predicting the water inflow during tunnel excavation is as follows:

[0038] In the formula, Q represents the inflow rate, measured in cubic meters per second (m³). 3 / h;q n The water volume of the nth segment is expressed in meters (m³). 3 / h;K n L is the permeability coefficient of the nth segment, expressed in m / d. n Let be the excavation length (m) of the nth segment; d be the equivalent diameter of the tunnel cross-section (m); and H be the water head height (m). This formula, based on Darcy's law, converts the water inflow from a small borehole diameter into an equivalent cross-sectional area and a permeability coefficient to calculate the water inflow under the tunnel cross-sectional dimensions. Its physical meaning is clear, and the calculation is simple.

[0039] Based on the on-site drilling conditions and calculation formulas, drilling parameters were statistically analyzed in segments. The permeability coefficient was determined by analyzing the difference in water inflow from the boreholes. In summary, it is estimated that the water inflow within the subsequent 30m excavation borehole will be approximately 174m³. 3 The predicted inflow rate is shown in Table 2 below.

[0040] Table 2. Prediction based on borehole water inflow

[0041] In some embodiments, the method further includes: calculating the total excavation water inflow based on the predicted water inflow of each segment, and forming a prediction table including the length of the geophysical anomaly segment, the water volume of the segment borehole, the segment permeability coefficient, and the predicted excavation water volume, so that on-site technicians can intuitively grasp the distribution and total amount of water inflow, and provide a quantitative basis for drainage capacity configuration.

[0042] The above method is particularly suitable for tunnel construction in areas with high-pressure fissure water development. It is used to assess the risks to the inclined shaft reverse slope drainage system after tunnel excavation and to formulate or adjust drainage plans and emergency plans accordingly.

[0043] Example 2 This embodiment provides a method for assessing water inflow during tunnel excavation based on high-pressure water inflow from advance exploratory boreholes, illustrated by an engineering example of a tunnel under construction traversing a large fault (hereinafter referred to as F1 fault). The tunnel has complex geological conditions, with lithology mainly consisting of sandstone interbedded with slate. Due to the influence of the fault structure, the rock mass is extremely fragmented, making it a potential high-pressure water inflow risk section.

[0044] The F1 fault strikes N10°-15°W / 70°-80°SW, intersecting the route at a small angle. Within the tunnel section, the fault's affected width is approximately 308 meters, intersecting the tunnel at mileages from D6K261+723 to D6K262+031, with a tunnel depth of approximately 227 meters. The current working face is at D6K262+019.3. The upper bench at this location reveals surrounding rock consisting of sandstone and slate interbedded with carbonaceous slate, a grayish-black color, exhibiting strong weathering interspersed with weak weathering. The rock mass has a thin-layered structure, with an attitude of N25°E / 60°NW. On-site observation reveals highly developed joints and fissures; the fissures on the left are filled with quartz veins, while the surrounding rock on the right is extremely fractured. Two main sets of joints are observed: Joint ① with an attitude of N85°W / 75°NE, and Joint ② with an attitude of N58°E / 35°SE. Affected by the F1 fault, the rock mass exhibits significant compression and twisting, poor bonding of structural surfaces, and poor surrounding rock stability. For example... Figure 2 As shown in (a) and (b), water is dripping from the face along the fissures, which is preliminarily identified as a weakly water-rich section. Due to the great burial depth and fractured structure, there is a possibility of high-pressure water inrush during subsequent excavation.

[0045] The implementation steps for assessing tunnel excavation water inflow based on high-pressure water inflow from pre-exploratory boreholes are as follows: S1. Based on the rock physical properties shown by the geophysical seismic reflection method (TSP), the borehole section is divided into several segments; Based on the geophysical anomaly classification criteria, the rock mass structure within the 30-meter borehole depth is divided into two segments, as shown in Table 3: Table 3 Rock mass structure classification

[0046] The first segment L1 corresponds to the mileage D6K262+019.3 ~ +026, with a length L1 = 6.7 meters.

[0047] The second segment L2 corresponds to the mileage D6K262+026 ~ +049.3, with a length L2 = 23.3 meters.

[0048] S2. Obtain the water output during the advanced horizontal drilling process of each section according to the drilling segment; To investigate the geological and hydrological conditions within a 30-meter radius ahead of the tunnel face, a horizontal borehole was drilled at D6K262+019.3. The borehole was positioned 3 meters below the arch crown, with a 5° upward angle, and terminated at D6K262+049.3, for a total drilling length L of 30 meters. During drilling, technicians meticulously recorded the real-time changes in borehole water inflow. Observations showed that the water inflow and pressure within the borehole remained relatively stable during drilling, satisfying the steady-flow assumption. Specific records are as follows: When drilling from the face (0 meters) to a depth of L1 = 6.7 meters (corresponding to mileage D6K262+026), the average borehole water inflow q1 was measured to be 2.7 m. 3 / h. The water inflow in this section is small, suggesting it is a relatively intact, weakly permeable rock mass.

[0049] When drilling progressed from 6.7 meters to a depth of L2 = 23.3 meters (corresponding to mileage D6K262+049.3), the average borehole water inflow q2 was measured to increase to 15 m³ / s. 3 / h. The sudden increase in water inflow in this section is presumed to be a tectonic fracture zone or a zone with dense fissures, belonging to a medium-permeability rock mass.

[0050] After drilling was completed, the water gushing from the borehole mouth formed a semi-hole stream with relatively high pressure. Figure 3 As shown, this visually reflects the risk of high water pressure ahead.

[0051] The corresponding borehole water inflow q for each segment n This is the average measured water volume within this section: q1 = 2.7 m. 3 / h, q2=15 m 3 / h.

[0052] S3. Based on the borehole sections and the water volume in each section, combined with the rock mass permeability classification standard, the permeability coefficient of different rock mass structures is initially determined; Based on empirical values ​​from rock mass permeability classification cases, and combined with the water inflow revealed by boreholes in each segment, a preliminary assessment of the permeability coefficient was made. For the first segment L1, the borehole water inflow was 2.7 m³. 3 / h, which falls under the "slightly permeable" category (water volume range 1~10 m³). 3 / h). The permeability coefficient is calculated using the reduction method: the maximum water volume for this grade is 10 m³. 3 The standard permeability coefficient is 0.0863 m / d. Therefore, K1 = (2.7 / 10) × 0.0863 = 0.0233 m / d, and the value is taken as 0.023 m / d. For the second section L2, the borehole inflow is 15 m³ / h. 3 / h, which falls under the "medium permeability" category (water volume range 10~50 m³ / h). 3 / h). Using the reduction method: the maximum water flow rate for this grade is 50 m³ / h, and the standard permeability coefficient is 8.63 m / d. Therefore, K2 = (15 / 50) × 8.63 = 2.589 m / d.

[0053] S4. Based on the water head height, the permeability coefficient, the depth of the borehole segments, and the equivalent diameter of the tunnel cross-section, predict the segmented water inflow during tunnel excavation.

[0054] This step uses the formula provided by this invention:

[0055] In this embodiment, the tunnel has a horseshoe-shaped cross-section, and the calculated equivalent diameter d of the tunnel cross-section is approximately 12 meters. The tunnel depth is approximately 227 meters, and the groundwater level is close to the surface; therefore, the water head is taken as 227 meters. The permeability coefficient K for each segment is... n and segment length L n This has been determined in steps S2 and S3.

[0056] Based on this, the predicted excavation water inflow for each segment is calculated: First segment =6.7m×2×3.14×0.023 m / d×227m / 1n(4×227m / 12m) =50.7 m 3 / d Note the consistency of units. Unit conversions are required here: permeability coefficient K is in m / d, length L is in m, diameter d is in m, and head H is in m. Calculation results should be in meters. 3 / d. Needs to be converted to m. 3 / h.

[0057] More precise calculation: 0.023m / d = 0.023 / 24 ≈ 0.0009583 m / h.

[0058] Q1=6.7m×2×3.14×0.0009583 m / h×227m / 1n(4×227m / 12m)=2.11 m 3 / h.

[0059] Similarly, Q2 = 23.3m × 2 × 3.14 × 2.589 / 24 m / h × 227m / 1n(4 × 227m / 12m) = 828.21 m 3 / h.

[0060] In summary, the maximum water inflow within the 30m section is Q1 + Q2 = 830.32 m³. 3 / h.

[0061] Example 3 This embodiment also provides an electronic device, including at least one processor, a memory communicatively connected to the at least one processor, and at least one input / output interface communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enable the at least one processor to perform the tunnel excavation water inflow assessment method based on high-pressure water inflow from advanced exploratory boreholes as described in Embodiment 1 above. The input / output interface may include a display, keyboard, mouse, and USB interface for inputting and outputting data.

[0062] The electronic device can be an electronic device for the client, such as a mobile phone, laptop, tablet, desktop computer, etc., to execute the tunnel excavation water inflow assessment method based on high-pressure water inflow in advance exploratory boreholes according to Embodiment 1.

[0063] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for assessing tunnel excavation water inflow based on high-pressure water inflow from pre-exploration boreholes, characterized in that, Includes the following steps: S1. Based on the physical characteristics of the surrounding rock shown by the geophysical seismic wave reflection method, the borehole section is divided into several segments to obtain the borehole segments; S2. Obtain the water output during the advanced horizontal drilling process of each section according to the drilling segment; S3. Based on the borehole sections and the water volume in each section, combined with the rock mass permeability classification standard, the permeability coefficient of different rock mass structures is initially determined; S4. Based on the water head height, the permeability coefficient, the depth of the borehole segments, and the equivalent diameter of the tunnel cross-section, predict the segmented water inflow during tunnel excavation.

2. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes as described in claim 1, characterized in that, Before tunnel excavation, if the variation range of water inflow and water pressure in the advanced horizontal exploratory boreholes does not exceed ±30%, the water inflow and water pressure in the advanced horizontal exploratory boreholes should be basically stable, exhibiting a stable flow phenomenon.

3. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes, as described in claim 1, is characterized in that... Based on the anomalies in the surrounding rock revealed by the geophysical seismic wave reflection method, the surrounding rock structure is segmented. The specific method includes: dividing the rock mass structure within the borehole length L into n segments, M1, M2, ..., Mn, according to the geophysical anomaly segmentation.

4. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes, as described in claim 3, is characterized in that... The specific method for obtaining the water volume during the drilling process of the advanced horizontal borehole is as follows: Record the advanced horizontal borehole with a borehole length L. When drilling reaches the geophysical exploration section M1, the depth is... Record the excavation length water volume of section When drilling reaches geophysical section M2, the depth is... Record the excavation length water volume of section When drilling reaches the geophysical exploration section Mn at a depth of L, record the excavation length. water volume of section .

5. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes, as described in claim 1, is characterized in that... Combining borehole segmentation and rock mass characteristics with case experience, permeability coefficients of different rock mass structures are preliminarily determined by interpolation through table lookup. The rock mass permeability classification standard includes extremely low permeability, low permeability, weak permeability, moderate permeability, strong permeability, and extremely high permeability levels. Each level is associated with a permeability coefficient range, rock mass characteristics, and borehole water volume.

6. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes according to claim 1, characterized in that, The rock mass permeability classification criteria are shown in the table below:

7. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes, as described in claim 6, is characterized in that... The method for initially determining the permeability coefficient is as follows: based on the ratio of the water volume in each section to the water volume revealed by the borehole, the standard permeability coefficient corresponding to the water volume revealed by the borehole is calculated by subtracting it.

8. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes according to claim 1, characterized in that, In step S4, the formula for predicting the water inflow volume in each tunnel excavation segment is as follows: In the formula, Q represents the inflow rate, measured in cubic meters per second (m³). 3 / h;q n The water volume of the nth segment is expressed in meters (m³). 3 / h;K n L is the permeability coefficient of the nth segment, expressed in m / d. n d is the excavation length (m) of the nth segment; d is the equivalent diameter of the tunnel cross-section (m); H is the water head height (m).

9. The method for assessing tunnel excavation water inflow based on high-pressure water inflow from advance exploratory boreholes according to claim 1, characterized in that, The method further includes: calculating the total excavation water inflow based on the predicted water inflow of each segment, and forming a prediction table including the borehole segments, the water volume of each segment borehole, the permeability coefficient of each segment, and the predicted excavation water volume.

10. An electronic device comprising at least one processor and a memory communicatively connected to said at least one processor; said memory storing instructions executable by said at least one processor, characterized in that, The instructions are executed by the at least one processor to enable the at least one processor to perform the method for evaluating tunnel excavation water inflow based on high-pressure water inflow from advanced exploratory boreholes, as described in any one of claims 1-9.

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