Stratum reinforcement method for shaft construction of recent water-rich sand layer

Abstract

The invention discloses a stratum reinforcement method for shaft construction of a recent water-rich sand layer, and relates to the technical field of solid potassium salt mine vertical shaft construction. The method comprises the steps of site leveling, measurement and hole arrangement, drilling, slurry preparation, high-pressure jet grouting, cleaning and backfilling. The core is that a double-row staggered three-flower-shaped hole distribution mode is adopted; in the high-pressure rotary jet grouting process, grouting parameters are dynamically adjusted through a preset algorithm model based on the grout return amount, the jet pressure and the vibration signal monitored in real time, and stratum self-adaptive intelligent regulation and control are achieved. And a staged composite slurry system is adopted, and a bionic root-shaped three-dimensional net-shaped curtain structure is formed at a specific depth. According to the method, integration of accurate and efficient reinforcement and reliable water stop of the loose and weak water-rich sand-bearing stratum is achieved, sand-bearing stratum water is blocked on the outer side of the jet grouting pile, the problems that construction is difficult, wall caving is prone to occurring and water permeation is prone to occurring in the stratum of this kind in a traditional method are solved, the construction safety and efficiency and the engineering quality are remarkably improved, and the construction cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of construction technology for vertical shafts in solid potassium salt mines, specifically to a method for reinforcing the strata during shaft construction in Neogene water-rich sand layers. Background Technology

[0002] Currently, the construction of potash mine shafts in Laos primarily employs conventional shaft sinking methods. Influenced by early regional geological structures, geological movements, and groundwater levels, the Neogene strata in Lao solid potash mining areas often contain thick layers of water-rich sand. These strata are mainly composed of medium-coarse sand, gravel, and clay, characterized by their softness, looseness, low bearing capacity and stability, and high permeability. Coupled with the high local groundwater level, this results in harsh and challenging construction conditions during shaft drilling through these strata, increasing the risk of major safety accidents such as rock spalling and water inrush, causing significant economic losses and severely impacting mine construction progress.

[0003] In existing technologies, some projects combine temporary surface drainage with temporary reinforcement of the excavated strata. However, this method is ineffective and unreliable in highly water-rich sandy layers. Other projects use surface curtain grouting to form a seepage barrier, but this process is complex, slow, requires a large grout volume, and is costly. Furthermore, the quality of the seepage barrier and its water-stopping effect are difficult to control in water-rich and sandy strata, thus limiting its application.

[0004] Therefore, there is an urgent need for a formation reinforcement method that can quickly and effectively reinforce the Neogene water-rich sand layer, achieve reliable water stoppage, and ensure safe and rapid well construction. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing technologies and provide a method for ground reinforcement during well construction in Neogene water-rich sand layers. This method addresses the technical problems of poor surrounding rock stability and high risk of water permeation during well construction in loose, weak, and water-rich sand layers, achieving integrated reinforcement and water-stopping, and improving construction efficiency and safety.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This application provides a method for ground reinforcement during well construction in Neogene water-rich sandy layers, including the following steps: Surface clearing and site leveling; The grouting holes are measured and located along the outer edge of the well wall structure to complete the measurement and hole positioning; Adjust the drilling rig's position and correct its verticality. Perform drilling operations according to the designed grouting depth, which penetrates the water-rich sand layer to be reinforced. Use silicate cement to prepare the grouting fluid; After setting the high-pressure jet grouting parameters and lowering the jet pipe to the design depth, high-pressure jet grouting is carried out from bottom to top. During the grouting process, the jet grouting parameters are dynamically adjusted based on the grouting parameters and vibration signals monitored in real time by sensors, using a preset algorithm model. Clean all pipelines after grouting is completed; Perform static pressure grouting until the grout no longer settles at the grouting hole.

[0007] Optionally, the step involves measuring and positioning the grouting holes along the outer edge of the well wall structure to complete the measurement and positioning of the holes. The multi-row grouting holes include: inner row grouting holes and outer row grouting holes. The centers of the inner row grouting holes and the outer row grouting holes are located on different circumferences concentric with the well wall, and the centers of the inner and outer rows grouting holes are arranged in an alternating manner.

[0008] Optionally, the step involves dynamically adjusting the jet grouting parameters based on real-time monitoring of grouting parameters and vibration signals by sensors, using a preset algorithm model. Specifically, this includes at least one of the following algorithm models: Algorithm Model 1: First Adjustment Model Based on Return Slurry Amount and Pressure Real-time monitoring of slurry return volume Q and injection pressure P; When Q remains consistently greater than the set threshold Q0, it is determined that the formation has entered a loose formation, and the output is adjusted accordingly. ; Speed ​​of improvement: ; When P is continuously greater than the set threshold P0 and Q is continuously less than the set threshold Q1, it is determined that a dense interlayer has been encountered, and the output is adjusted: start the repeated swinging jet program. Algorithm Model 2: Second Adjustment Model Based on Vibration Spectrum Analysis Vibration time-domain signals are acquired using a high-frequency vibration sensor. The spectrum is obtained by performing a fast Fourier transform on it. :

[0009] in, This represents the time-domain waveform of the vibration signal acquired from the high-frequency vibration sensor. Indicates vibration signal The frequency domain representation obtained after Fast Fourier Transform For frequency, For time, ∫ represents time. Integration operations; Calculate the correlation coefficient ρ between the current spectrum and the pre-stored stratigraphic standard spectrum library:

[0010] in, The correlation coefficient is... For the pre-stored stratigraphic standard spectrum, for covariance, For the current spectrum standard deviation Standard spectrum Standard deviation; If the correlation coefficient between ρ and a certain type of formation is higher than the confidence threshold, it is determined that the formation has entered that type of formation, and the corresponding preset grouting strategy is executed.

[0011] Optionally, the steps include setting high-pressure jet grouting parameters, lowering the jetting pipe to the designed depth, and then performing high-pressure jet grouting from bottom to top. The high-pressure jet grouting employs a staged composite grout system, which includes at least: The first slurry contains a quick-setting component and a fiber-reinforcing component; The second slurry contains water-retaining components and water-reducing dispersing components; The third slurry has a water-cement ratio greater than 1:1; The control system controls the sequential switching of the slurry system based on the lifting depth and / or real-time monitoring data.

[0012] Optionally, the grouting fluid may also contain pre-absorbed zeolite powder, microcapsules containing mineralizing microorganisms, and nano-silica; the pre-absorbed zeolite powder is used for internal curing of the formed pile body, the mineralizing microorganisms are activated after contact with water to heal microcracks that may occur in the pile body in the later stage, and the nano-silica is used to improve the long-term strength of the pile body.

[0013] Optionally, in the high-pressure jet grouting process from bottom to top, the high-pressure jet is controlled to be directionally sprayed laterally within a specific depth range of at least some of the grouting holes, thereby forming a radially reinforced consolidation body outside the vertical main jet grouting pile body. The reinforced consolidation body connects adjacent vertical piles into an integral network structure in three-dimensional space.

[0014] Optionally, during the steps of adjusting the drilling rig's position and correcting its verticality, and conducting drilling operations according to the designed grouting depth, the verticality of the borehole is ensured through phased re-measurement and adjustment. The error between the drill rod center and the designed grouting hole position is controlled within a preset first accuracy range.

[0015] Optionally, in the step of using silicate cement to prepare the grout, the water-cement ratio of the grout ranges from 0.7:1 to 1:1; and / or, the fineness of the ordinary silicate cement used in the grout meets a preset standard; and / or, the grout is filtered before use.

[0016] Optionally, if the high-pressure jet grouting is interrupted for any reason during the bottom-up high-pressure jet grouting process, an overlapping spraying procedure shall be performed when construction resumes; wherein the length of the overlapping is determined according to the duration of the interruption.

[0017] Optionally, the method is based on Building Information Modeling (BIM) for integrated management; the BIM platform performs the following operations: Before construction, a three-dimensional digital model containing geological information, well casing, and designed pile locations should be established. During construction, drilling rig positioning data, real-time monitoring of grouting parameters, vibration spectrum identification results, and dynamic adjustment instructions are integrated. The actual construction status of each pile and the sensed stratum information are dynamically updated in the three-dimensional digital model to generate a visualized digital archive of the entire process and provide quality early warning.

[0018] Compared with the prior art, the present invention has the following significant advantages: By introducing an intelligent algorithm model based on multi-sensor data fusion, real-time identification of complex strata and dynamic optimization and adjustment of grouting process are achieved, solving the problem of poor adaptability of fixed parameter processes. A double-row staggered hole layout and a staged composite grout system, combined with a biomimetic three-dimensional curtain structure, form a continuous curtain with high strength, high integrity, and high impermeability, significantly improving load-bearing and water-stopping performance. By introducing internal curing, self-healing, and nano-reinforcing components into the grout, the jet grouting pile body is endowed with the ability to continuously increase strength and autonomously repair micro-damage, extending the service life of the well shaft. Based on the BIM platform, the entire process from design, construction to acceptance is visualized and traceable, enabling refined management that greatly improves the control level of project quality and construction efficiency. This invention combines reinforcement and water-stopping into one, with a highly efficient and reliable process that can significantly shorten the construction period and reduce project costs, making it particularly suitable for the construction of potash mine vertical shafts in Laos and other regions. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the plan layout of jet grouting piles for a method of reinforcing the strata in a Neogene water-rich sand layer well construction, as disclosed in an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the cross-sectional layout of jet grouting piles for a wellbore construction and ground reinforcement method for a Neogene water-rich sand layer, as disclosed in an embodiment of the present invention.

[0021] Attached reference numerals: 1. Inner grouting hole; 2. Outer grouting hole; 3. Center of the inner grouting hole; 4. Center of the outer grouting hole; 5. Well wall structure; 6. High-pressure jet grouting pile; 7. Neogene water-rich sand layer; 8. Lower strata. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Furthermore, elements in this invention are referred to as being "fixed to" or "set on" another element, which may be directly on the other element or may also include an intervening element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or may also include an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementations.

[0024] Example 1 Please see Figures 1-2 This application provides a method for ground reinforcement during well construction in a recent water-rich sandy layer, comprising the following steps: Steps S1-S7 Step S1. Surface clearing and site leveling.

[0025] Step S2. Measure and locate the grouting holes along the outer edge of the well wall structure to complete the measurement and hole positioning; the multiple rows of grouting holes include: inner row of grouting holes and outer row of grouting holes; the centers of the inner row of grouting holes and the outer row of grouting holes are located on different circumferences concentric with the well wall, and the centers of the inner and outer rows of grouting holes are arranged alternately; as a preferred embodiment, the grouting holes are arranged in two rows along the outer edge of the well wall structure, the center of the inner row of grouting holes is 350 mm from the outer edge of the well wall structure, the center of the outer row of grouting holes is 650 mm from the outer edge of the well wall structure, the spacing between the centers of the grouting holes in the same row is 400 mm, and the spacing between the centers of the inner and outer rows of grouting holes is 300 mm. The relevant parameters can be adjusted according to the diameter of the jet grouting pile. The centers of the inner and outer rows of grouting holes are concentric with the well wall circle.

[0026] Step S3. Adjust the drilling rig's position and correct its verticality. Perform drilling operations according to the designed grouting depth, which penetrates the water-rich sand layer to be reinforced. The verticality of the borehole is ensured through phased re-measurement and adjustment. The error between the drill rod center and the designed grouting hole position is controlled within a preset first accuracy range. As a preferred embodiment, correcting the drilling rig's verticality specifically means ensuring that the error between the drill rod center and the designed grouting hole position is within 50mm.

[0027] Step S4. Use silicate cement to prepare grouting fluid; wherein, as a preferred embodiment, the grout is prepared using ordinary silicate cement with a grade not lower than P·O42.5, and the water-cement ratio is 1:0.7~1:1.

[0028] Furthermore, the grouting fluid also contains pre-absorbed zeolite powder, microcapsules containing mineralizing microorganisms, and nano-silica; the pre-absorbed zeolite powder is used for internal curing of the formed pile body, the mineralizing microorganisms are activated after contact with water to heal microcracks that may occur in the pile body in the later stage, and the nano-silica is used to improve the long-term strength of the pile body.

[0029] Furthermore, ordinary silicate cement should meet the requirement that the residue on an 80μm square-hole sieve is no more than 5%, and the water used for slurry preparation must meet the requirements for mixing hydraulic concrete. The slurry must be strictly filtered before use to avoid clogging of the spray pipe.

[0030] Step S5. Set the high-pressure jet grouting parameters, lower the jet pipe to the design depth, and perform high-pressure jet grouting from bottom to top; during the grouting process, based on the grouting parameters and vibration signals monitored in real time by the sensors, the jet grouting parameters are dynamically adjusted through a preset algorithm model.

[0031] In this embodiment, to achieve intelligent dynamic control of the grouting process, the present invention deploys a multi-sensor fusion monitoring system, specifically including: a high-pressure jet pressure sensor, installed on the main outlet pipeline of the high-pressure mud pump or at the top interface of the jet pipe, for real-time monitoring of the jet pressure (P); a slurry flow meter, installed on the same high-pressure pipeline, for measuring the grouting flow rate; a return slurry flow meter, installed at the inlet of the surface return slurry guide channel or slurry collection box, for monitoring the return slurry volume (Q); and a core high-frequency vibration sensor at the borehole opening, rigidly installed on the drilling rig mast near the borehole opening or at the borehole guide base, for collecting the vibration time-domain signal (v(t)) transmitted through the drill pipe, which can be used to identify the stratum lithology after spectral analysis. In addition, the system is also connected to the drilling rig control system to read the lifting speed and rotation speed. All sensor data are transmitted to the central control system in real time, providing multi-source input for the pre-set intelligent algorithm model, realizing real-time perception of stratum changes and automatic adjustment of grouting parameters.

[0032] In this embodiment, the grouting borehole deviation rate is mainly affected by the sand layer, pebble layer, and whetstone layer. During drilling, a uniform drilling method is adopted. Every three grouting pipes are lowered, the verticality of the drill rod and drill rig track is re-measured. If deviation is found, the verticality of the drill rig is adjusted in time, and drilling continues until the design depth is reached. In addition, if the high-pressure jet grouting work is stopped for any reason, before resuming construction, the nozzle should be lowered by 0.5 meters and overlapped before continuing to lift and grout. The interruption depth and time should be recorded. If grouting work is stopped for more than 2 hours, the pump body and grout delivery pipeline must be cleaned before construction can continue.

[0033] In this embodiment, during the high-pressure jet grouting from bottom to top, the high-pressure jet is controlled to be directionally sprayed laterally within a specific depth range of at least some of the grouting holes, thereby forming a radially reinforced consolidation body outside the vertical main jet grouting pile body. The reinforced consolidation body connects adjacent vertical piles into an integral network structure in three-dimensional space.

[0034] In this embodiment, high-pressure jet grouting is carried out using a staged composite grout system. The grout system includes at least: a first grout containing a quick-setting component and a fiber-reinforcing component; a second grout containing a water-retaining component and a water-reducing and dispersing component; and a third grout with a water-cement ratio greater than 1:1. The control system controls the sequential switching of the grout system for injection based on the lifting depth and / or real-time monitoring data.

[0035] In this embodiment, high-pressure jet grouting parameters are set, and grouting is performed by jet grouting through a lower pipe. The deviation rate of the grouting hole is controlled below 3%. Generally speaking, the high-pressure jet grouting parameters are: grout pressure 25-28 MPa; lifting speed 15-25 cm / min; jet flow rate 50-100 L / min; rotation speed 20 r / min. The aforementioned pre-defined algorithm models specifically include at least one of the following algorithm models: Algorithm Model 1: First Adjustment Model Based on Return Slurry Amount and Pressure Real-time monitoring of slurry return volume Q and injection pressure P; When Q remains consistently greater than the set threshold Q0, it is determined that the formation has entered a loose formation, and the output is adjusted accordingly. ; Speed ​​of improvement: ; When P is continuously greater than the set threshold P0 and Q is continuously less than the set threshold Q1, it is determined that a dense interlayer has been encountered, and the output is adjusted: start the repeated swinging jet program. Algorithm Model 2: Second Adjustment Model Based on Vibration Spectrum Analysis Vibration time-domain signals are acquired using a high-frequency vibration sensor. The spectrum is obtained by performing a fast Fourier transform on it. :

[0036] in, This represents the time-domain waveform of the vibration signal acquired from the high-frequency vibration sensor. Indicates vibration signal The frequency domain representation obtained after Fast Fourier Transform For frequency, For time, ∫ represents time. Integration operations; Calculate the correlation coefficient ρ between the current spectrum and the pre-stored stratigraphic standard spectrum library:

[0037] in, The correlation coefficient is... For the pre-stored stratigraphic standard spectrum, for covariance, For the current spectrum standard deviation Standard spectrum Standard deviation; If the correlation coefficient between ρ and a certain type of formation is higher than the confidence threshold, it is determined that the formation has entered that type of formation, and the corresponding preset grouting strategy is executed.

[0038] In this embodiment, as a preferred implementation, the final pile diameter of the high-pressure jet grouting is 500 mm, the spacing between the pile cores in the same row is no more than 400 mm, the interlocking thickness of the piles in the same row is no less than 100 mm, and the inner and outer rows of piles are interlocked in a triangular shape with an interlocking thickness of no less than 200 mm.

[0039] Step S6. Clean all pipelines after grouting is completed; Step S7. Perform static pressure grouting until the grout no longer sinks at the grouting hole.

[0040] In one specific embodiment, in the step of preparing the grouting fluid with silicate cement, the water-cement ratio of the grout is in the range of 0.7:1 to 1:1; and / or, the fineness of the ordinary silicate cement used in the grout meets a preset standard; and / or, the grout is filtered before use.

[0041] In one specific implementation, during the high-pressure jet grouting process from bottom to top, if the high-pressure jet grouting is interrupted for any reason, an overlapping spraying procedure is performed when construction resumes; wherein, the length of the overlapping is determined according to the duration of the interruption.

[0042] Specifically: During the jet grouting process, when encountering strata with gelatinous, strongly, or moderately weathered interlayers, drilling is required first. If no such strata are encountered, the jet grout can be lowered directly. To prevent nozzle clogging, water or grout is supplied simultaneously with the jet grout as it is lowered to the design depth. Once the jet grout has reached the design depth, jetting is performed for 1-3 minutes. After the injected grout emerges, the jet grout is then simultaneously jetted, rotated, and lifted from bottom to top at a predetermined lifting and rotation speed until the design elevation is reached.

[0043] In one specific implementation, the method is based on Building Information Modeling (BIM) for integrated management; the BIM platform performs the following operations: Before construction, a three-dimensional digital model containing geological information, well casing, and designed pile locations should be established. During construction, drilling rig positioning data, real-time monitoring of grouting parameters, vibration spectrum identification results, and dynamic adjustment instructions are integrated. The actual construction status of each pile and the sensed stratum information are dynamically updated in the three-dimensional digital model to generate a visualized digital archive of the entire process and provide quality early warning.

[0044] Example 2 Based on Example 1, this example applies the method of the present invention to cross the Neogene water-rich sand layer in a vertical shaft project of a potash mine in Laos.

[0045] Construction preparation: Clear and level the site around the well shaft.

[0046] Measuring the fabric aperture: as attached Figure 1 As shown, two rows of grouting holes are arranged along the outer edge of the well wall structure. The center of the inner row of holes is 350mm from the well wall, and the center of the outer row of holes is 650mm from the well wall. The center distance between the holes in the same row is 400mm, and the center distance between the inner and outer rows of holes is 300mm. The center circles of the inner row of holes, the outer row of holes, and the well wall are concentric.

[0047] Drilling: Position the drilling rig, correct the verticality, and ensure that the error between the drill rod center and the designed hole position is less than 50mm. Drill to the designed depth, penetrating the water-rich sand layer to enter the lower stable strata. Recheck the verticality after every three drilled sections.

[0048] Slurry preparation: Use P·042.5 grade ordinary Portland cement, and control the residue on an 80μm square mesh sieve to be ≤5%. Prepare composite slurries with water-cement ratios of 0.8:1 (first slurry, with added water glass and polypropylene fiber), 1:1 (second slurry, with added bentonite and water-reducing agent, and added pre-absorbent zeolite powder, microbial capsules and nano silica), and 1.2:1 (third slurry). All slurries are filtered before use.

[0049] High-pressure jet grouting: Parameter settings: injection pressure 26MPa, lifting speed 20cm / min, rotation speed 20r / min.

[0050] Intelligent control: Spraying begins after the pipe reaches the designed depth. During the process, the system monitors the return slurry volume, pressure, and vibration signals in real time. When Algorithm Model 2 identifies a quicksand layer through spectrum analysis (correlation coefficient ρ>0.8), the system automatically switches to the first slurry and appropriately increases the pressure and decreases the lifting speed. When encountering a gravel layer (P is consistently high and Q is low), the system automatically initiates oscillating spraying.

[0051] Forming a biomimetic structure: At key depths, the nozzles are controlled to perform directional lateral spraying, forming a structure as shown in the image. Figure 2The radially reinforced consolidation structure shown connects adjacent high-pressure jet grouting piles into a network.

[0052] Interruption handling: If interruption occurs for any reason, when resuming, lower the pipe by 0.5m and perform overlapping spraying; if the interruption exceeds 2 hours, clean the pipeline.

[0053] Cleaning and backfilling: After grouting a single hole, immediately clean the pipeline. Then, perform static pressure backfilling grouting on all grouting holes until the grout at the hole opening no longer settles.

[0054] BIM Management: The entire process is monitored through the BIM platform, integrating all data and displaying construction progress and quality cloud maps in real time, thus achieving digital management.

[0055] Experimental Example Comparative experiment of the reinforcement effect of the method of the present invention and the traditional high-pressure jet grouting method 1. Experimental Objective The invention verifies the superiority of the "intelligent dynamic control high-pressure jet grouting method" proposed in this invention over the traditional fixed-parameter high-pressure jet grouting method in terms of pile quality, water-stopping performance, and construction efficiency when reinforcing Neogene water-rich sand layers.

[0056] 2. Experimental Site and Geological Conditions Site: The experimental site was selected as the typical Neogene water-rich sandy layer area that the shaft of a potash mine in Laos was to traverse.

[0057] Geological conditions: According to the survey, the experimental strata are mainly medium-coarse sand, interspersed with gravel lenses and discontinuous clay interlayers, with a groundwater level at a depth of 2.0 meters. This stratum has a heterogeneous structure and high permeability, making it an ideal location for testing the adaptive capabilities of this invention.

[0058] 3. Experimental Design Two experimental zones were set up in adjacent areas, and different construction methods were used for each zone: Comparison area: Traditional high-pressure rotary jet spraying method is used.

[0059] Hole layout: Single row of grouting holes, with a spacing of 1.2 meters between pile cores.

[0060] Grout: Pure cement grout with a single water-cement ratio (1:1).

[0061] Parameters: Fixed injection pressure 25MPa, lifting speed 25cm / min.

[0062] Control: No real-time monitoring or dynamic adjustment.

[0063] Invention area: The method of this invention is adopted.

[0064] Hole arrangement: double row, staggered arrangement (parameters same as in the embodiment).

[0065] Slurry: A staged composite slurry system (same as the example).

[0066] Parameters: The baseline parameters are the same as those in the comparison area, but the intelligent dynamic control system is enabled.

[0067] Control: Real-time feedback and feedforward control based on slurry return volume, pressure, and vibration spectrum.

[0068] 4. Detection methods and data Twenty-eight days after construction was completed, excavation and core drilling tests were conducted on the two experimental areas. Key data comparisons are as follows:

[0069] The comparative experimental data above clearly demonstrate that, in terms of pile quality, the jet grouting piles produced by this invention are far superior to those produced by traditional methods in terms of diameter, strength, uniformity, and integrity. Regarding core functionality, the curtain constructed by this invention achieves an order-of-magnitude improvement in impermeability, effectively sealing water-rich sand layers. In terms of construction efficiency, this invention, through intelligent and adaptive control, significantly improves construction efficiency, pile quality reliability, and material utilization, while reducing the time and cost of handling abnormal geological conditions.

[0070] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0071] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for ground reinforcement during well construction in Neogene water-rich sandy layers, characterized in that, Includes the following steps: Surface clearing and site leveling; The grouting holes are measured and located along the outer edge of the well wall structure to complete the measurement and hole positioning; Adjust the drilling rig's position and correct its verticality. Perform drilling operations according to the designed grouting depth, which penetrates the water-rich sand layer to be reinforced. Use silicate cement to prepare the grouting fluid; After setting the high-pressure jet grouting parameters and lowering the jet pipe to the design depth, high-pressure jet grouting is carried out from bottom to top. During the grouting process, the jet grouting parameters are dynamically adjusted based on the grouting parameters and vibration signals monitored in real time by sensors, using a preset algorithm model. Clean all pipelines after grouting is completed; Perform static pressure grouting until the grout no longer settles at the grouting hole.

2. The method according to claim 1, characterized in that, The steps involve measuring and locating the grouting holes along the outer edge of the well wall structure to complete the measurement and positioning of the holes. The multiple rows of grouting holes include: inner row of grouting holes and outer row of grouting holes. The center of the inner row of grouting holes and the center of the outer row of grouting holes are located on different circumferences concentric with the well wall, and the centers of the inner and outer rows of grouting holes are arranged alternately.

3. The method according to claim 1, characterized in that, The steps involve dynamically adjusting the jet grouting parameters based on real-time monitoring of grouting parameters and vibration signals by sensors, using a preset algorithm model. Specifically, this includes at least one of the following algorithm models: Algorithm Model 1: First Adjustment Model Based on Return Slurry Amount and Pressure Real-time monitoring of slurry return volume Q and injection pressure P; When Q remains consistently greater than the set threshold Q0, it is determined that the formation has entered a loose formation, and the output is adjusted accordingly. ； Speed ​​of improvement: ； When P is continuously greater than the set threshold P0 and Q is continuously less than the set threshold Q1, it is determined that a dense interlayer has been encountered, and the output is adjusted: start the repeated swing spray program. Algorithm Model 2: Second Adjustment Model Based on Vibration Spectrum Analysis Vibration time-domain signals are collected using a high-frequency vibration sensor. The spectrum is obtained by performing a fast Fourier transform on it. : ； in, This represents the time-domain waveform of the vibration signal acquired from the high-frequency vibration sensor. Indicates vibration signal The frequency domain representation obtained after Fast Fourier Transform For frequency, For time, ∫ represents time. Integration operations; Calculate the correlation coefficient ρ between the current spectrum and the pre-stored stratigraphic standard spectrum library: ； in, The correlation coefficient is... For the pre-stored stratigraphic standard spectrum, for covariance, For the current spectrum standard deviation Standard spectrum Standard deviation; If the correlation coefficient between ρ and a certain type of formation is higher than the confidence threshold, it is determined that the formation has entered that type of formation, and the corresponding preset grouting strategy is executed.

4. The method according to claim 1 or 3, characterized in that, The steps involve setting the high-pressure jet grouting parameters, lowering the jet pipe to the designed depth, and then performing high-pressure jet grouting from bottom to top. The high-pressure jet grouting employs a staged composite grout system, which includes at least the following components: The first slurry contains a quick-setting component and a fiber-reinforcing component; The second slurry contains water-retaining components and water-reducing dispersing components; The third slurry has a water-cement ratio greater than 1:1; The control system controls the sequential switching of the slurry system based on the lifting depth and / or real-time monitoring data.

5. The method according to claim 4, characterized in that, The grouting fluid also contains pre-absorbed zeolite powder, microcapsules containing mineralizing microorganisms, and nano-silica. The pre-absorbed zeolite powder is used for internal curing of the formed pile body, the mineralizing microorganisms are activated after contact with water to heal microcracks that may occur in the pile body in the later stage, and the nano-silica is used to improve the long-term strength of the pile body.

6. The method according to claim 1, characterized in that, In the high-pressure jet grouting process, which proceeds from bottom to top, the high-pressure jet is controlled to be directionally sprayed laterally within a specific depth range of at least some of the grouting holes, thereby forming a radially reinforced consolidation body outside the vertical main jet grouting pile body. The reinforced consolidation body connects adjacent vertical piles into an integral network structure in three-dimensional space.

7. The method according to claim 2, characterized in that, The process involves adjusting the drilling rig's position, correcting its verticality, and drilling according to the designed grouting depth. The verticality of the borehole is ensured through phased re-measurement and adjustment. The error between the drill rod center and the designed grouting hole position is controlled within a preset first accuracy range.

8. The method according to claim 1, characterized in that, In the step of preparing the grout using silicate cement, the water-cement ratio of the grout ranges from 0.7:1 to 1:1; and / or, the fineness of the ordinary silicate cement used in the grout meets a preset standard; and / or, the grout is filtered before use.

9. The method according to claim 1, characterized in that, If the high-pressure jet grouting is interrupted for any reason during the bottom-up high-pressure jet grouting process, an overlapping spraying procedure will be performed when construction resumes; wherein, the length of the overlapping is determined according to the duration of the interruption.

10. The method according to claim 1, characterized in that, The method is based on Building Information Modeling (BIM) for integrated management; the BIM platform performs the following operations: Before construction, a three-dimensional digital model containing geological information, well casing, and designed pile locations should be established. During construction, drilling rig positioning data, real-time monitoring of grouting parameters, vibration spectrum identification results, and dynamic adjustment instructions are integrated. The actual construction status of each pile and the sensed stratum information are dynamically updated in the three-dimensional digital model to generate a visualized digital archive of the entire process and provide quality early warning.

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