A method for detecting the effect of pre-grouting on the ground of a vertical shaft by geophysical logging

Abstract

The application discloses a method for detecting the effect of ground pre-grouting of a vertical shaft by using geophysical logging, before grouting, 1-3 grouting holes are selected and drilled to the designed depth; a geophysical logging system is arranged; the selected grouting holes are subjected to geophysical logging before and after grouting by using the geophysical logging system; the physical properties of the stratum reflected by the geophysical logging data of the grouting holes before and after grouting are compared and analyzed, the change trend of the water conductivity and stability of the grouted stratum is obtained, and the grouting water plugging and reinforcement effect is evaluated. The geophysical logging method is used for detecting the water plugging and reinforcement effect of the ground pre-grouting of a vertical shaft, and a simple and reliable evaluation method is provided, the defects of large hydrological test error and slow excavation measurement lag in the current evaluation method are overcome, the stratum condition information and guidance are provided for the grouting engineering construction, reliable basis is provided for the grouting engineering acceptance, and technical support is provided for the application of the ground pre-grouting technology of a vertical shaft and the safe and rapid construction of a vertical shaft.

Description

Technical Field

[0001] This invention relates to the technical field of methods for detecting the pre-grouting effect on the surface of vertical shafts. Specifically, it is a method for detecting the pre-grouting effect on the surface of vertical shafts using geophysical logging. Background Technology

[0002] Vertical shafts are widely used in mining, transportation, tunneling, and water conservancy. When encountering aquifers or soft, fractured rock formations, surface pre-grouting is a common water-blocking and reinforcement technique. This involves drilling holes in the ground and injecting prepared grout into the rock formation via a grouting pump and pipelines. After the grout solidifies, it seals water channels or consolidates loose, fractured rock, forming a curtain around the shaft within a certain range, thus achieving water blocking or reinforcement and ensuring safe and rapid shaft construction. Surface pre-grouting is a hidden underground project, and due to the complexity and heterogeneity of geological conditions, there has been no reliable and effective means to inspect and evaluate the grouting effect. Currently, there are two main methods for inspecting the effectiveness of surface pre-grouting in vertical shafts:

[0003] (1) Hydrological test

[0004] By conducting water pressure, injection, or pumping tests on the grouting formation through the final grouting hole, hydrological parameters such as permeability or water flow rate after grouting are calculated, and the remaining wellbore inflow is derived to evaluate the improvement in permeability and water conductivity, thus assessing the grouting effect. However, hydrological test calculation methods are based on certain assumptions, such as homogeneity and isotropy. Due to the complexity and heterogeneity of formation conditions, hydrological calculation results often contain significant errors, making it impossible to accurately evaluate the water-blocking effect of grouting and to assess the reinforcement effect of grouting.

[0005] (2) Actual excavation inspection

[0006] After grouting is completed, the remaining water inflow is calculated and the rock mass consolidation is observed through actual observations during the excavation and lining of the well shaft, thus evaluating the grouting's water-blocking and reinforcement effects. This method is the most intuitive and accurate, but it is a post-incident inspection and cannot guide the prevention, adjustment, and remediation of surface pre-grouting, which is not conducive to ensuring the quality of surface pre-grouting construction.

[0007] Geophysical logging (or simply well logging) utilizes the geophysical properties of rock formations, such as electrochemical, electrical, acoustic, and radioactive characteristics, to measure geophysical parameters through boreholes. This allows for the study of borehole geological profiles, the detection of valuable minerals, and the resolution of underground geological problems. Well logging methods are widely used in coal, petroleum, metallic and non-metallic mineral resources, as well as hydrogeology and engineering geology, but have not yet been applied to the detection of the effectiveness of surface pre-grouting in vertical shafts. Summary of the Invention

[0008] Therefore, the technical problem to be solved by the present invention is to provide a method for geophysical logging to detect the effect of surface pre-grouting in vertical shafts. By combining logging tests to measure the changes in the physical properties of the grouting strata before and after grouting, the method interprets and analyzes the improvement in the water conductivity and overall strength of the grouting strata, thereby evaluating the effect of grouting and water plugging reinforcement, guiding grouting construction, and serving as an important basis for the acceptance of grouting projects.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0010] A method for geophysical logging to detect the surface pre-grouting effect of vertical shafts includes the following steps:

[0011] (A) Before grouting, select 1 to 3 grouting holes and drill to the designed depth;

[0012] (B) Deploy the geophysical logging system;

[0013] (C) Use geophysical logging systems to perform pre-grouting geophysical logging on the injection section of the selected grouting hole;

[0014] (D) Grout the grouting holes. After grouting is completed, select 1 to 3 grouting holes and drill to the designed depth.

[0015] (E) Geophysical logging is performed on the injection section of the selected grouting hole using a geophysical logging system after grouting.

[0016] (F) Compare and analyze the formation physical characteristics reflected by the geophysical logging data of the injection section of the grouting hole before and after grouting, obtain the changing trend of the water conductivity and stability of the injection formation, and evaluate the effect of grouting water plugging and reinforcement.

[0017] In the above-mentioned method for geophysical logging to detect the surface pre-grouting effect of vertical shafts, in step (A), before grouting, 1 to 3 grouting holes are selected, drilled to the designed depth, and the flushing fluid is adjusted in time to complete the flushing of the grouting holes, ensuring that the rock cuttings sedimentation and flushing fluid concentration in the hole are within the allowable range, and ensuring that the designed logging depth is reached and the safety of the hole is guaranteed.

[0018] The above-mentioned method for geophysical logging to detect the surface pre-grouting effect of a vertical shaft includes, in step (B), a geophysical logging system comprising downhole instruments, logging cables, and surface instruments inside a logging vehicle; one end of the logging cable is connected to the downhole instruments, and the other end is connected to the surface instruments inside the logging vehicle; the downhole instruments are used to receive or detect relevant signals in the surrounding medium, including resistivity signals, acoustic signals, natural gamma signals, natural potential signals, and wellbore signals, as well as well inclination, azimuth, and well temperature parameters; the logging cables are used to raise and lower the downhole instruments, determine the depth of the downhole instruments, and are responsible for communication between the surface instruments and equipment and the downhole instruments; the surface instruments are used to process and record the measurement signals from the downhole instruments.

[0019] The above-mentioned method for geophysical logging to detect the surface pre-grouting effect of vertical shafts

[0020] (B-1) Drive the logging truck to a suitable position next to the grouting hole, adjust the direction, check the ground instruments and the downhole instruments to be lowered in the logging truck, and install the lower pulley and upper pulley using the drilling rig frame and the drilling rig traveling trolley (4);

[0021] (B-2) Pass one end of the logging cable through the lower and upper pulleys, connect the downhole instruments, and then carefully place it into the grouting hole.

[0022] In the above-mentioned method for geophysical logging to detect the surface pre-grouting effect of vertical shafts, in step (C):

[0023] (C-1) Downlink Logging: Lower downhole instruments at the required speed as specified in the specifications. During the descent, the downhole instruments perform logging operations and transmit the logging data to the surface instruments via the logging cable.

[0024] (C-2) Upward logging: After the downhole logging reaches the designed depth, the downhole instrument is raised at the speed required by the specification. The downhole instrument performs logging during the upward process and transmits the logging data to the surface instrument through the logging cable.

[0025] (C-3) After logging is completed, the logging data collected by the ground instruments is processed and interpreted to form a result map, which can be used to guide grouting construction.

[0026] In the above-mentioned method for geophysical logging to detect the surface pre-grouting effect of a vertical shaft, in step (D), after grouting is completed, a grouting hole is drilled again according to the method in step (A); in step (E), geophysical logging is performed after grouting according to the method in step (C) to obtain logging data after grouting.

[0027] The above-mentioned method for detecting the surface pre-grouting effect of a vertical shaft using geophysical logging, in steps (C) and (E), involves the geophysical logging system detecting the effect before and after grouting. Acoustic waves and resistivity are used to evaluate the grouting effect; natural gamma ray, spontaneous potential, and well diameter are used for lithological identification and classification; and well inclination, azimuth, and well temperature are used to understand the borehole trajectory and geothermal changes.

[0028] In the above-mentioned method for geophysical logging to detect the surface pre-grouting effect of vertical shafts, the judgment criteria for the aquifer section in step (F) are as follows: after grouting, if the resistivity of the grouted section increases significantly and the acoustic velocity increases significantly, with the resistivity value of the aquifer section after grouting increasing by more than 30% and the acoustic velocity value after grouting increasing by more than 20% compared to before grouting, combined with other geological data and grouting construction data, it can be determined that the water-bearing performance of the aquifer section has been significantly reduced, and the grouting water-blocking effect has been achieved.

[0029] The above-mentioned method for geophysical logging to detect the surface pre-grouting effect of vertical shafts, in step (F), the criteria for judging the fractured section are as follows: after grouting, if the acoustic wave velocity of the fractured section increases significantly, the overall acoustic wave velocity value after grouting is more than 30% higher than before grouting, the resistivity increases significantly, the overall apparent resistivity value after grouting is more than 20% higher than before grouting, and there is no obvious well diameter enlargement, combined with other geological data and grouting construction data, it can be determined that the rock mass strength and integrity of the fractured section are significantly improved, and the grouting reinforcement effect is achieved.

[0030] The technical solution of the present invention achieves the following beneficial technical effects:

[0031] Applying geophysical logging methods to detect the effectiveness of surface pre-grouting and water plugging reinforcement in vertical shafts provides an advanced, simple, and reliable evaluation method for surface pre-grouting in vertical shafts. This overcomes the shortcomings of current evaluation methods, such as large errors in hydrological tests and delayed timeliness of excavation measurements. It also provides more information and guidance on geological conditions for grouting engineering construction, a reliable basis for grouting engineering acceptance, and better technical support for the application of surface pre-grouting technology in vertical shafts and the safe and rapid construction of vertical shafts.

[0032] The criteria for determining the aquifer section are as follows: after grouting, if the resistivity of the grouting section increases significantly and the acoustic velocity increases significantly, with the overall resistivity of the aquifer section increasing by more than 30% and the overall acoustic velocity increasing by more than 20% after grouting, combined with other geological data and grouting construction data, it can be determined that the water-bearing performance of the aquifer section has been significantly reduced, and the grouting has achieved the effect of water plugging.

[0033] The criteria for determining the fractured section are as follows: after grouting, if the acoustic velocity of the fractured section increases significantly, with the overall acoustic velocity value after grouting being more than 30% higher than before grouting, and the resistivity increases significantly, with the apparent resistivity value after grouting being more than 20% higher than before grouting, and there is no obvious well diameter enlargement, then combined with other geological data and grouting construction data, it can be determined that the rock mass strength and integrity of the fractured section have been significantly improved, achieving the grouting reinforcement effect. Attached Figure Description

[0034] Figure 1 A schematic diagram of the geophysical logging system of this invention;

[0035] Figure 2 Plan view of the arrangement of vertical shaft grouting holes and cross-hole resistivity CT in the embodiment;

[0036] Figure 3 Comparison of logging curves in the embodiments (all);

[0037] Figure 4a Figure 3Comparison of logging curves of boreholes S3 and S2 before and after grouting (within the red box in the middle) (partial):

[0038] The 380.10–385.59 m segment (only observe the blue acoustic time difference curve and the black apparent resistivity curve);

[0039] Figure 4b Figure 3 Comparison of logging curves of boreholes S3 and S2 before and after grouting within the red box (partial): 451.2~468m segment (only look at the blue sonic transit time curve and the black apparent resistivity curve).

[0040] The reference numerals in the figure are as follows: 1-logging vehicle, 2-lower pulley, 3-upper pulley, 4-drilling rig traveling block, 5-drill tower, 6-grouting hole casing, 7-logging cable, 8-downhole instruments, 9-grouting hole. Detailed Implementation

[0041] Depending on the geophysical parameters measured, geophysical logging is divided into electrical logging (measuring resistivity), acoustic logging (measuring acoustic wave velocity or amplitude), and radioactive logging (measuring radioactive concentration, such as natural gamma logging or effects produced under artificial radioactive conditions, such as gamma-gamma logging and neutron logging). Many logging methods have been developed, such as apparent resistivity logging, lateral logging, microelectrode logging, natural gamma logging, gamma-gamma logging, neutron-neutron logging, neutron-gamma logging, acoustic logging, caliper logging, and well fluid resistivity logging.

[0042] The main purpose of grouting is to plug water and reinforce the formation, that is, to improve the water-bearing characteristics, strength, and stability of the formation.

[0043] (a) The main parameters reflecting the water-bearing characteristics and geophysical parameters of the formation are electrical parameters, such as resistivity and spontaneous potential. Formations with more pores and abundant water have lower resistivity, and vice versa.

[0044] (b) Geophysical parameters reflecting the strength and stability of strata are mainly elastic wave velocity and resistivity. Dense, strong and stable strata have higher elastic wave velocity and higher resistivity, while weak strata have lower elastic wave velocity and lower resistivity.

[0045] (c) In addition, the natural γ value usually increases with the increase of the mud content of sedimentary rocks, and the spontaneous potential also reflects the mud content of the strata, which is of great significance for the division of aquifers.

[0046] (d) In formations with high strength and good stability, the grouting hole diameter is small, close to the drill bit diameter; conversely, the well diameter is easily enlarged.

[0047] Therefore, when geophysical logging is used to detect the grouting effect, methods such as apparent resistivity logging, sonic logging, natural gamma logging, spontaneous potential logging, and caliper logging can be used to help divide the formation and comprehensively evaluate the grouting effect, but they should not be used as quantitative standards to judge the grouting effect.

[0048] Take the Xianglushan Tunnel, Section 2 of the Dali Phase I construction project in the Dianzhong Water Diversion Project, as an example.

[0049] 1. Overview

[0050] The Dianzhong Water Diversion Project is a landmark project among my country's major water-saving and water-supply projects. The project consists of two parts: a water source project and a water conveyance project. The water source project is located in Shigou Town, Yulong County, drawing water from the Jinsha River about 1.5 kilometers upstream of Shigou Town and pumping it to the main canal. The water conveyance project starts at Wangchengpo in Shigou Town, Lijiang, passing through Lijiang City, Dali Prefecture, Chuxiong Prefecture, Kunming City, and Yuxi City, ending at Xinpobei in Honghe Prefecture.

[0051] The Xianglushan Tunnel, Section 2 of the Dali Phase I construction of the Dianzhong Water Diversion Project, is located in Lijiang City. To expedite construction, a new vertical shaft was added at the Xianglushan Tunnel. The shaft traverses strata primarily consisting of Triassic Beiya Formation limestone, dolomitic limestone, and Tertiary intrusive andesitic basalt. The surrounding rock is unstable and rich in groundwater. To ensure construction safety and the smooth progress of the project, grouting and water-blocking reinforcement treatment was required around the shaft before construction.

[0052] The wellbore surface grouting project is designed using a straight-hole + S-hole scheme. Straight-hole grouting is performed on the upper and middle strata within the wellbore depth range. After completion, the drilling equipment is moved to a location farther from the wellbore center, and the S-hole scheme is used to grout the lower and middle strata within the wellbore depth range. While the S-holes are being constructed, the excavation and lining of the upper wellbore can begin, allowing the excavation and lining of the upper wellbore to proceed simultaneously with the grouting of the lower wellbore, thus shortening the overall construction period.

[0053] After the borehole is formed, the aquifer around the well is treated by the downhole segmented grouting method to form a water-blocking curtain. Clay cement grout is mainly used for grouting, combined with a certain amount of single-liquid cement grout to reinforce large karst caves and fractured strata.

[0054] The design parameters for grouting holes are shown in Table 1 and... Figure 1 :

[0055] Table 1 Drilling Design Parameters

[0056]

[0057] Based on the analysis of the current research status at home and abroad, there is no existing method for checking and evaluating the pre-grouting effect of vertical shafts using geophysical exploration. Therefore, this project aims to study methods for detecting and evaluating the grouting effect using geophysical logging.

[0058] 2. Specific Exploration Plan

[0059] To study soft rock grouting technology and evaluate its effectiveness, geophysical logging was conducted in the same area before and after grouting. The grouting effect was evaluated by assessing the changes in physical properties before and after grouting.

[0060] (A) Before grouting, see Figure 2 Select the S3 grouting hole and drill to the designed depth; after grouting, select the S2 grouting hole and perform well logging exploration.

[0061] Before grouting, select grouting hole S3. After grouting, select grouting hole S2. Drill to the designed depth and adjust the flushing fluid in time to complete the flushing of the grouting hole. Ensure that the rock cuttings sedimentation and flushing fluid concentration in the hole are within the allowable range, and ensure that the designed logging depth is reached and the hole is safe.

[0062] Based on the on-site progress conditions, the logging depth of the S3 grouting hole is 360–518 m, and the logging depth of the S2 grouting hole is 360–570 m. The comparison before and after grouting is only for the 360–518 m section.

[0063] (B) Deploy the geophysical logging system;

[0064] like Figure 1 As shown, the geophysical logging system includes a downhole instrument 8, a logging cable 7, and a surface instrument inside the logging vehicle 1. One end of the logging cable 7 is connected to the downhole instrument 8, and the other end is connected to the surface instrument inside the logging vehicle 1. The downhole instrument 8 is used to receive (or detect) relevant signals in the surrounding medium, including resistivity signals and acoustic signals. The logging cable 7 is used to raise and lower the downhole instrument 8, determine the depth of the downhole instrument, and is responsible for communication between the surface instrument and equipment and the downhole instrument. The surface instrument is used to process and record the measurement signals from the downhole instrument 8.

[0065] (B-1) Drive the logging truck 1 to a suitable position next to the grouting holes 9 (S2 grouting hole and S3 grouting hole), adjust the direction, check the ground instruments and the downhole instruments 8 to be lowered in the logging truck 1, and install the lower pulley 2 and upper pulley 3 using the drilling rig frame 5 and the drilling rig traveling trolley 4.

[0066] (B-2) Pass one end of the logging cable 7 through the lower pulley 2 and the upper pulley 3, then connect the downhole instrument 8, and then carefully place it into the grouting hole 9 (grouting hole S2 and grouting hole S3).

[0067] (C) Use geophysical logging system to perform pre-grouting geophysical logging on the injection section of the selected grouting hole 9 (grouting hole S2 and grouting hole S3);

[0068] (C-1) Downlink Logging: The downhole instrument 8 is lowered at the speed required by specifications. During the descent, the downhole instrument 8 performs logging and transmits the logging data to the surface instruments via the logging cable 7.

[0069] (C-2) Upward logging: After the downlink logging reaches the designed depth, the downhole instrument 8 is raised at the speed required by the specification. The downhole instrument 8 performs logging during the upward process and transmits the logging data to the surface instrument through the logging cable 7.

[0070] (C-3) After logging is completed, the logging data collected by the ground instruments is processed and interpreted to form a result map, which can be used to guide grouting construction.

[0071] (D) Use the geophysical logging system to perform post-grouting geophysical logging on the injection section of the selected grouting hole 9; perform post-grouting geophysical logging according to the method in step (C), obtain post-grouting logging data, process and interpret it, and form a result map.

[0072] After logging is completed, the logging data is processed and interpreted. Data processing mainly includes depth alignment, slope correction, smoothing filtering, and environmental correction to ensure that each logging parameter corresponds more accurately to the target rock layer, eliminate interference, and standardize the logging data. Then, an interpretation model is established for each logging parameter, reasonable interpretation parameters are determined, and the geological parameters of each rock layer are calculated. Combined with other geological data, the geological characteristics reflected by the logging are interpreted, and logging result curves are output. By analyzing and comparing the logging data and curves before and after grouting, combined with other geological data and grouting construction data, the grouting water plugging and reinforcement effect can be evaluated.

[0073] In this embodiment, the logging methods include compensated acoustic logging (AC), three-lateral apparent resistivity (NR), natural gamma (GR), spontaneous potential (SP), and wellbore diameter (CAL), as well as parameters such as well inclination, azimuth (DEVI, AZIM), and well temperature (TEMP). Natural gamma (GR), spontaneous potential (SP), and wellbore diameter parameters are mainly used for lithological identification and classification, while well inclination, azimuth, and well temperature are used to understand the borehole trajectory and geothermal changes. Compensated acoustic logging and three-lateral apparent resistivity are mainly used for evaluating grouting effectiveness.

[0074] (F) Compare and analyze the formation physical characteristics reflected by the geophysical logging data of the injection section of the grouting hole before and after grouting, obtain the changing trend of the water conductivity and stability of the injection formation, and evaluate the effect of grouting water plugging and reinforcement.

[0075] Geophysical logging was performed on borehole S3 before grouting and on borehole S2 after grouting. The grouting effect was evaluated by comparing the results before and after grouting. See Figure 3 .

[0076] from Figure 4a and Figure 4b As can be seen, before grouting, borehole S3 had two distinct weak aquifer sections: ① 380.10–385.59 m and ② 451.2–468 m. After grouting, the wave velocity and resistivity of borehole S2 corresponding to section ① (weak aquifer section) did not decrease significantly, except for a diameter increase in the 385–387.1 m section. Similarly, there was no significant decrease in wave velocity and resistivity in section ② (weak aquifer section), except for a slight decrease at a depth of approximately 454 m. The comparison of wave velocity and resistivity before and after grouting is shown in Tables 2 and 3. This indicates that after grouting, the resistivity and wave velocity of the fractured aquifer section were significantly improved, achieving both reinforcement and water-blocking effects.

[0077] Table 2 Comparison of longitudinal wave velocities before and after grouting

[0078]

[0079] Table 3 Comparison of resistivity values ​​before and after grouting

[0080]

[0081] Based on experience gained during construction, the following judgment criteria are summarized:

[0082] The criteria for determining the aquifer section are as follows: after grouting, if the resistivity of the grouting section increases significantly and the acoustic velocity increases significantly, with the overall resistivity of the aquifer section increasing by more than 30% and the overall acoustic velocity increasing by more than 20% after grouting, combined with other geological data and grouting construction data, it can be determined that the water-bearing performance of the aquifer section has been significantly reduced, and the grouting has achieved the effect of water plugging.

[0083] The criteria for determining the fractured section are as follows: after grouting, if the acoustic velocity of the fractured section increases significantly, the overall acoustic velocity value after grouting is more than 30% higher than before grouting, the resistivity increases significantly, the overall apparent resistivity value after grouting is more than 30% higher than before grouting, and there is no obvious well diameter enlargement, combined with other geological data and grouting construction data, it can be determined that the rock mass strength and integrity of the fractured section are significantly improved, and the grouting reinforcement effect is achieved.

[0084] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A method for detecting the surface pre-grouting effect of a vertical shaft using geophysical logging, characterized in that, Includes the following steps: (A) Before grouting, select 1 to 3 grouting holes (9) and drill to the designed depth; (B) Deploy the geophysical logging system; (C) Use geophysical logging system to perform pre-grouting geophysical logging on the injection section of the selected grouting hole (9); (D) Grout the grouting holes (9). After grouting is completed, select 1 to 3 grouting holes and drill to the designed depth. (E) Geophysical logging is performed on the injection section of the selected grouting hole (9) using a geophysical logging system after grouting. (F) Compare and analyze the formation physical characteristics reflected by the geophysical logging data of the injection section of the grouting hole before and after grouting, obtain the changing trend of the water conductivity and stability of the injected formation, and evaluate the grouting water plugging and reinforcement effect. In steps (C) and (E), the geophysical logging system detects the effects before and after grouting. Acoustic and resistivity signals are used to evaluate the grouting effect; natural gamma signals, spontaneous potential signals, and well caliper signals are used for lithology identification and classification; and well inclination, azimuth, and well temperature parameters are used to understand the borehole trajectory and geothermal changes. In step (F), the criteria for determining the aquifer section are as follows: after grouting, if the resistivity of the grouting section increases significantly and the acoustic velocity increases significantly, with the resistivity of the aquifer section increasing by more than 30% and the acoustic velocity increasing by more than 20% after grouting, combined with other geological data and grouting construction data, it can be determined that the water-bearing performance of the aquifer section has been significantly reduced, and the grouting has achieved the water-blocking effect. In step (F), the criteria for determining the fractured section are as follows: after grouting, if the acoustic velocity of the fractured section increases significantly, the overall acoustic velocity value after grouting is more than 30% higher than before grouting, the resistivity increases significantly, the overall apparent resistivity value after grouting is more than 20% higher than before grouting, and there is no obvious well diameter enlargement, combined with other geological data and grouting construction data, it can be determined that the rock mass strength and integrity of the fractured section are significantly improved, and the grouting reinforcement effect is achieved.

2. The method for detecting the surface pre-grouting effect of a vertical shaft using geophysical logging according to claim 1, characterized in that, In step (A), before grouting, select 1 to 3 grouting holes (9), drill to the designed depth, adjust the flushing fluid in time, and complete the flushing of the grouting holes (9) to ensure that the rock cuttings sedimentation and flushing fluid concentration in the hole are within the allowable range, and to ensure that the designed logging depth and the safety in the hole are achieved.

3. The method for detecting the surface pre-grouting effect of a vertical shaft using geophysical logging according to claim 1, characterized in that, In step (B), the geophysical logging system includes a downhole instrument (8), a logging cable (7), and a surface instrument inside the logging vehicle (1); one end of the logging cable (7) is connected to the downhole instrument (8), and the other end of the logging cable (7) is connected to the surface instrument inside the logging vehicle (1); the downhole instrument (8) is used to receive or detect relevant signals in the surrounding medium, including resistivity signals, acoustic signals, natural gamma signals, natural potential signals, and wellbore signals, as well as well inclination, azimuth, and well temperature parameters; the logging cable (7) is used to lift and lower the downhole instrument (8), determine the depth of the downhole instrument, and is responsible for communication between the surface instrument and equipment and the downhole instrument; The surface instruments are used to process and record the measurement signals from the downhole instruments (8).

4. The method for detecting the surface pre-grouting effect of a vertical shaft using geophysical logging according to claim 3, characterized in that, (B-1) Drive the logging truck (1) to a suitable position next to the grouting hole (9), adjust the direction, check the ground instruments and the downhole instruments (8) to be lowered in the logging truck (1), and install the lower pulley (2) and upper pulley (3) using the drilling rig frame (5) and the drilling rig traveling trolley (4). (B-2) Pass one end of the logging cable (7) through the lower pulley (2) and the upper pulley (3), then connect the downhole instrument (8), and then carefully place it into the grouting hole (9).

5. The method for detecting the surface pre-grouting effect of a vertical shaft using geophysical logging according to claim 4, characterized in that, In step (C): (C-1) Downlink Logging: The downhole instrument (8) is lowered at the specified speed. During the descent, the downhole instrument (8) performs logging and transmits the logging data to the surface instrument via the logging cable (7). (C-2) Upward logging: After the downward logging reaches the designed depth, the downhole instrument (8) is raised at the speed required by the specification. The downhole instrument (8) performs logging during the upward process and transmits the logging data to the surface instrument through the logging cable (7). (C-3) After logging is completed, the logging data collected by the ground instruments is processed and interpreted to form a result map, which can be used to guide grouting construction.

6. The method for detecting the surface pre-grouting effect of a vertical shaft using geophysical logging according to claim 5, characterized in that, In step (D), after grouting is completed, grouting holes (9) are drilled again according to the method in step (A); in step (E), geophysical logging is performed after grouting according to the method in step (C) to obtain logging data after grouting.

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