Construction method of soft soil roadbed with high groundwater level in fish pond section

Abstract

The application discloses a construction method of a soft soil roadbed of a fish pond section with a high underground water level, which comprises the following steps: sequentially performing water pumping, dredging and replacement treatment on a fish pond flow plastic silt foundation, laying mud and stones to form an operation platform after the replacement treatment is completed, and the operation platform is used for bearing a pile machine to carry out construction operation; according to design drawings and on-site survey results, accurate line laying is performed on the operation platform after the pretreatment is completed to determine a pile position, the pile position is marked and then is reviewed to ensure that a pile position deviation meets relevant specification requirements; the pile machine of a cement mixing pile is moved to the preset pile position, a pile frame is adjusted to a vertical state, a four-spraying-four-mixing + pile end double-stopping piling process is adopted, each process of spraying, stopping and lifting is completed according to a preset time sequence, and preset construction parameters are matched to ensure that the pile body is uniformly and densely mixed; after the construction of a single pile body is completed, the step S300 is repeated until the construction of all the pile bodies is completed. The application effectively improves the reinforcement quality and construction safety of the soft soil roadbed and takes into account the construction efficiency and economy.

Description

Technical Field

[0001] This invention belongs to the field of road construction technology, and more specifically, relates to a construction method for soft soil subgrade with high groundwater level in fishpond areas. Background Technology

[0002] With the rapid advancement of infrastructure construction such as municipal roads and water conservancy projects, soft soil foundation treatment has become a core aspect of engineering construction. Among these technologies, cement mixing piles have become the mainstream technology for soft soil foundation reinforcement due to their advantages such as minimal construction disturbance, controllable costs, and wide applicability. They are widely used in various engineering projects for soft soil foundation treatment. Especially in areas with dense fishponds and high groundwater levels, cement mixing piles forcibly mix the solidifying agent with the soft soil, causing the soft soil to harden and form piles with a certain strength and integrity. These piles work synergistically with the soil between the piles to form a composite foundation, effectively improving the bearing capacity of the foundation, controlling post-construction settlement, and meeting the basic requirements of engineering construction.

[0003] Currently, in soft soil foundation treatment projects with high groundwater levels in fishpond areas, conventional cement mixing pile construction schemes have formed a preliminary technical system, covering basic aspects such as site pretreatment, pile location layout, and mixing and pile formation. However, in actual engineering applications, fishpond areas are characterized by thick layers of fluid-plastic silt, high groundwater levels, and complex construction conditions. Simultaneously, the safety protection of existing structures such as high-voltage power towers must be considered. Existing construction schemes are gradually revealing many shortcomings, failing to meet the construction needs under complex conditions. Conventional mixing processes often employ basic spraying and mixing methods, which are unsuitable for the reinforcement requirements of deep soft soil in fishponds, easily leading to quality problems such as uneven pile mixing, loose pile ends, and grout interruption. Furthermore, there is a lack of standardized handling procedures for sudden failures such as grout interruption and machine shutdown, resulting in poor pile continuity and insufficient bearing capacity. In addition, existing construction schemes do not allow for flexible process switching. When constructing around existing structures such as high-voltage power towers, it is impossible to balance the safety of the structures with the soft soil foundation reinforcement effect, often resorting to relocating the structures or abandoning partial reinforcement, resulting in poor economy and practicality. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, this invention provides a construction method for soft soil subgrades with high groundwater levels in fishpond areas. By optimizing the site pretreatment and pile position control system, and implementing supporting protective and precise positioning measures, it avoids construction safety hazards, ensures the reliability of the construction foundation, and adapts to the special working conditions of fishponds. Through innovative four-spraying and four-mixing + double-stop pile-forming process and standardized closed-loop fault handling, and through targeted measures such as re-spraying and re-mixing, pipeline cleaning, and pile replacement, it avoids defects such as broken piles and mud inclusions, ensuring the continuity of the pile body. By flexibly switching between two processes in high-voltage power tower sections, it resolves the contradiction between protecting existing structures and reinforcing soft soil foundations, improves the project's economy and applicability, and broadens its application scope.

[0005] To achieve the above objectives, the present invention provides a construction method for soft soil subgrade with high groundwater level in fishpond areas, comprising the following steps: S100: The fishpond's fluidized silt foundation is sequentially pumped out, dredged, and replaced. After the replacement is completed, mudstone is laid to form a working platform, which is used to support the pile driver to carry out construction operations. S200: Based on the design drawings and on-site survey results, accurately lay out the pile positions on the pre-processed work platform to determine the pile positions. After marking the pile positions, conduct a verification to ensure that the pile position deviations meet the relevant specifications. S300: Move the cement mixing pile driver to the preset pile position, adjust the pile frame to a vertical state, and adopt the four-spray four-mix + pile end double stop pile forming process. Complete the spraying, stopping and lifting processes according to the preset sequence, and match the preset construction parameters to ensure that the pile body is mixed evenly and densely. S400: After the construction of a single pile is completed, repeat step S300 until the construction of all piles is completed.

[0006] Furthermore, in step S100, the silt is dredged and replaced to 30cm below the designed elevation of the pile top, and then a 30cm thick layer of mudstone is laid to form a working platform.

[0007] Furthermore, in step 200, the pile position determination is carried out by using a total station for precise positioning, with a pile position deviation of no more than 5cm. The piles are marked with red and white paint. The verification adopts a double inspection system, with construction personnel and supervisors jointly verifying the piles. Only after the verification is qualified can the subsequent construction procedures be carried out.

[0008] Further, step S300 specifically includes: S310: As the drill rod sinks, the shotcrete equipment is started simultaneously to spray grout. After the drill rod sinks to the designed position at the pile end, it is paused for 30 seconds to ensure that the grout at the pile end is full and dense. S320: After the first stop at the pile tip is completed, the drill rod is lifted and grouting is continued to be sprayed to complete the first lifting and grouting mixing of the pile body. S330: After the drill rod is raised to the designated position, it is lowered again and grouting continues. After it is lowered to the pile end position, it is held for 30 seconds to enhance the mixing effect of the pile end and the pile body. S340: After the second stop at the pile tip, the drill rod is raised again and grouting continues to be sprayed to complete the mixing and pile forming operation of the entire pile body; The preset construction parameters are as follows: the lifting speed is controlled at 0.5 to 0.8 m / min, the cement dosage is controlled at 60 kg / m, and the water-cement ratio is controlled at 0.5 to 0.6.

[0009] Furthermore, in step S300, if a grouting interruption occurs during the construction of the cement mixing pile, the lifting operation is immediately stopped, the drill rod is lowered to 0.5m below the grouting interruption point, and the grouting equipment is restarted for re-grouting and re-mixing.

[0010] Furthermore, in step S300, if the downtime exceeds 3 hours due to power outage or pipe blockage during the construction of cement mixing piles, the drill rod is immediately removed, the pipe is thoroughly cleaned with clean water, and after the equipment is restored to normal, the original pile foundation is continued to be constructed at the original construction location. After the original pile foundation is completed, a new pile foundation is installed at its adjacent location.

[0011] Furthermore, in the same road soft soil treatment project, the construction process is divided according to the safe distance between the construction area and the high-voltage power tower: for conventional construction sections not restricted by the safe distance of the high-voltage power tower, the cement mixing pile process is used for soft soil treatment; for construction sections within the safe distance range of the high-voltage power tower, the high-pressure jet grouting pile process is switched to be used for soft soil treatment.

[0012] Furthermore, the construction process of the high-pressure jet grouting pile is as follows: the high-pressure jet grouting equipment is moved to the preset pile position, clean water or thin slurry is used as the drilling medium, the drilling rig is controlled to drill at a uniform speed until the designed pile bottom depth is reached, the high-pressure grouting equipment at the bottom of the hole is turned on, and the drill rod is controlled to rotate at a uniform speed and slowly lifted upward. The impact force of the high-pressure slurry is used to cut and mix the soil around the hole, so that the slurry and the soil are fully mixed, ensuring that the slurry and the soil are evenly mixed to form a continuous and complete pile body, until the drill rod is lifted to the designed elevation of the pile top, and the construction of a single high-pressure jet grouting pile is completed.

[0013] Furthermore, if a grouting interruption occurs during high-pressure jet grouting pile construction, the lifting operation should be stopped immediately, the drill rod should be lowered to 0.5m below the grouting interruption point, and the jet grouting equipment should be restarted for re-jetting and re-mixing. If the downtime exceeds 3 hours due to abnormal situations such as power outages or pipe blockages during construction, the drill rod should be removed immediately, and the pipeline should be thoroughly cleaned with clean water. After the equipment is restored to normal, the original pile foundation should be supplemented at the original construction location. After the original pile foundation is completed, a new pile foundation should be installed at the adjacent location.

[0014] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects: 1. This invention discloses a construction method for soft soil subgrade with high groundwater level in fishpond areas. By sequentially implementing pumping, dredging, replacement, and laying of mud-stone working platforms on the fluid plastic silt subgrade of the fishpond, and setting up a temporary drainage system, slope protection piles, and impermeable membrane, it solves problems such as soft soil overturning, pile driver entrapment, and slope collapse. At the same time, it adopts a total station for precise layout combined with a double inspection system to strictly control pile position deviation. Through clear marking and multiple calibrations, it ensures accurate pile positioning, laying a solid foundation for subsequent pile construction. It achieves synergistic effect of pretreatment and pile position control, improves construction safety and early construction efficiency, and is suitable for the special working conditions of fishponds with high groundwater level and fluid plastic silt.

[0015] 2. This invention provides a construction method for soft soil subgrade with high groundwater levels in fishpond areas. By employing a four-spray, four-mix + double-stop pile-forming process, combined with precisely matched construction parameters, it solves common quality problems in traditional processes such as uneven pile mixing, loose pile ends, and voids. This method improves the density, strength, and bonding force of the piles with the soft soil. Simultaneously, it establishes standardized closed-loop handling rules for sudden failures such as grout interruption and prolonged downtime. Through targeted measures such as re-spraying and re-mixing, pipeline cleaning, and pile replacement, it avoids defects such as broken piles and mud inclusions, ensuring pile continuity. Combined with comprehensive construction records, it achieves quality traceability, further enhancing the bearing capacity of the composite foundation and meeting the reinforcement needs of deep soft soil foundations in fishponds.

[0016] 3. The present invention provides a construction method for soft soil subgrade with high groundwater level in fishpond areas. It proposes a dual-process flexible switching method for high-voltage power tower sections. Based on the safe distance between the construction area and the high-voltage power tower, it flexibly switches between cement mixing piles and high-pressure jet grouting piles. Cement mixing piles are used in conventional sections to ensure economy and construction efficiency, while high-pressure jet grouting piles with compact size are used within the safe range of the high-voltage power tower to avoid safety risks. There is no need to relocate the power tower or abandon local reinforcement. It takes into account both the protection of existing structures and the reinforcement effect of soft soil foundation, improves the economy and applicability of the project, and broadens the application scenarios of the present invention.

[0017] 4. The present invention provides a construction method for soft soil subgrade with high groundwater level in fishpond areas. Through supporting measures such as skip pile construction, pile head slurry removal, full-process construction record, and quality acceptance, it integrates all aspects of site pretreatment, pile location, pile construction, and fault handling to form an integrated closed-loop management system. This effectively improves the stability and controllability of construction quality, increases the first-pass yield rate, reduces construction costs and quality risks, and fills the gap in existing technology for integrated construction of the entire process under complex conditions in fishponds. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart illustrating a construction method for a soft soil subgrade with a high groundwater level in a fishpond area, according to an embodiment of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0020] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0021] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0022] In this patent, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0023] Example 1 like Figure 1 As shown in the figure, this embodiment of the invention provides a construction method for soft soil subgrade with high groundwater level in fishpond areas, including the following steps: S100: The fishpond's fluidized silt foundation is sequentially pumped out, dredged, and replaced. After the replacement is completed, mudstone is laid to form a working platform, which is used to support the pile driver to carry out construction operations. Before pumping, a temporary drainage system must be set up around the fishpond. High-powered sewage pumps are used in groups to pump water, and the groundwater level is monitored in real time during the pumping process to control the pumping rate and prevent the surrounding soil from settling and collapsing due to a sudden drop in water level. At the same time, protective piles and impermeable membranes are installed on the slopes of the fishpond to prevent soil from the outside from flowing into the fishpond and affecting the dredging operation. During dredging, excavators are used in conjunction with manual cleaning. After dredging, well-graded crushed stone or lime-soil is used for replacement. During the replacement process, it is laid and compacted in layers, with each layer controlled to a thickness of 20-30cm. Compaction is carried out using a small road roller until the design compaction standard is met. After the replacement is completed, mud-bound stones are immediately laid to form a working platform, ensuring that the bearing capacity of the working platform meets the requirements of the pile driver construction and preventing settlement or tilting during pile driver operation, which would affect the construction quality.

[0024] S200: Based on the design drawings and on-site survey results, accurately lay out the pile positions on the pre-processed work platform to determine the pile positions. After marking the pile positions, conduct a verification to ensure that the pile position deviations meet the relevant specifications. Before setting out the lines, the surface of the work platform must be leveled and cleaned, removing debris and loose soil to ensure a flat reference surface. A total station is used for precise positioning during the setting out process. First, the control points of the roadbed axis are determined according to the design drawings. Then, using these control points as a reference, the coordinates of each pile position are set out point by point. The instrument needs to be calibrated multiple times during the setting out process to reduce measurement errors. Pile positions are marked with red and white paint, with a circle of at least 10cm in diameter drawn at the center of each pile position. A double-check system is used for verification, with both construction and supervision personnel jointly verifying the coordinates. During verification, the pile coordinates are remeasured using a total station and compared with the design coordinates to ensure that the pile position deviation does not exceed the specifications. The clarity and accuracy of the pile position markings are also checked. Only after verification is passed can subsequent construction procedures proceed. If the verification reveals that the pile position deviation exceeds the standard, the lines must be set out again, marked, and verified again until it is satisfactory.

[0025] S300: Move the cement mixing pile driver to the preset pile position, adjust the pile frame to a vertical state, and adopt the four-spray four-mix + pile end double stop pile forming process. Complete the spraying, stopping and lifting processes according to the preset sequence, and match the preset construction parameters to ensure that the pile body is mixed evenly and densely. Before the pile driver is positioned, the performance of the equipment must be checked, including the mixing shaft speed, grouting pump pressure, and lifting speed, to ensure normal operation. Simultaneously, the verticality of the pile frame must be checked using a level and plumb bob for double calibration, ensuring the vertical deviation is no more than 1%. The pile forming process employs a four-spray, four-mix technique: grouting and mixing twice during the pile driver's descent and twice during lifting. The descent speed is controlled at 0.8-1.2 m / min, the lifting speed at 0.5-0.8 m / min, and the grouting pressure maintained at 0.3-0.5 MPa. A double-stop process is required at the pile tip: when the mixing shaft reaches the designed pile tip elevation, it stops for a certain time while grouting continues to ensure the pile tip is fully filled with cement grout. Pre-set construction parameters must be determined based on the properties of the soft soil and the required bearing capacity of the foundation.

[0026] S400: After the construction of a single pile is completed, repeat step S300 until the construction of all piles is completed.

[0027] After the construction of a single pile is completed, the laitance at the pile head must be cleaned promptly, and records such as pile number, construction time, and construction personnel must be kept for subsequent quality traceability. For batch construction, a skip-pile construction method should be adopted to avoid mutual interference between adjacent piles, which could affect pile quality. The spacing between skipped piles should be no less than twice the pile diameter. After all piles are constructed, a comprehensive quality inspection of the pile body is required. Only after passing the inspection can the next roadbed construction procedure proceed.

[0028] Furthermore, in step S100, the silt is dredged and replaced to 30cm below the designed elevation of the pile top, and then a 30cm thick layer of mudstone is laid to form a working platform.

[0029] The dredging and backfilling to 30cm below the design elevation of the pile top is to allow for the thickness of the mud-bearing stone working platform. This prevents the platform from encroaching on the effective length of the pile after its installation, ensuring a proper connection between the top of the pile and the roadbed structure. The mud-bearing stone thickness is strictly controlled at 30cm, using graded mud-bearing stone. It is laid and compacted in layers using a small road roller. The bearing capacity meets the operational requirements, ensuring the stability of the piling machine during operation without significant settlement. This provides a flat and solid working foundation for subsequent pile positioning and piling machine construction. Simultaneously, a drainage slope must be set around the mud-bearing stone working platform to promptly drain rainwater and surface water, preventing water accumulation and softening of the platform, which could affect its bearing capacity.

[0030] Furthermore, in step 200, the pile position determination is carried out by using a total station for precise positioning, with a pile position deviation of no more than 5cm. The piles are marked with red and white paint. The verification adopts a double inspection system, with construction personnel and supervisors jointly verifying the piles. Only after the verification is qualified can the subsequent construction procedures be carried out.

[0031] Before positioning with a total station, the instrument must be calibrated to ensure measurement accuracy. Positioning is performed using the coordinate method, combined with on-site survey results, to correct for measurement errors caused by terrain undulations, ensuring that the pile coordinates are consistent with the design drawings. Pile position deviation must be strictly controlled within 5cm to avoid affecting the pile's load-bearing capacity and the overall stability of the roadbed due to excessive deviation. Red and white paint markings must be clear and conspicuous. In low light or rainy conditions, reflective markers can be placed at the marked locations to facilitate pile driver alignment. During the double-inspection verification process, construction personnel first conduct a self-inspection. After passing the self-inspection, the work is submitted to the supervisor for re-inspection. The re-inspection requires re-measuring the pile coordinates and checking the integrity of the markings. If problems such as pile position deviation or blurred markings are found during the re-inspection, immediate rectification is required. The piles must be re-laid out, re-marked, and re-checked until the requirements are met. It is strictly forbidden to proceed to the next stage without re-inspection or with an unqualified re-inspection.

[0032] Further, step S300 specifically includes: S310: As the drill rod sinks, the shotcrete equipment is started simultaneously to spray grout. After the drill rod sinks to the designed position at the pile end, it is paused for 30 seconds to ensure that the grout at the pile end is full and dense. S320: After the first stop at the pile tip is completed, the drill rod is lifted and grouting is continued to be sprayed to complete the first lifting and grouting mixing of the pile body. S330: After the drill rod is raised to the designated position, it is lowered again and grouting continues. After it is lowered to the pile end position, it is held for 30 seconds to enhance the mixing effect of the pile end and the pile body. S340: After the second stop at the pile tip, the drill rod is raised again and grouting continues to be sprayed to complete the mixing and pile forming operation of the entire pile body; The preset construction parameters are as follows: the lifting speed is controlled at 0.5 to 0.8 m / min, the cement dosage is controlled at 60 kg / m, and the water-cement ratio is controlled at 0.5 to 0.6.

[0033] Before lowering the drill rod, check the grouting pipe for blockages to avoid affecting grouting. During lowering, maintain a uniform speed and precise grouting to ensure even penetration of the grout into the soft soil, avoiding missed or insufficient grouting. After lowering to the pile tip, pause to allow the grout to fill the voids and enhance its bonding with the soil, preventing voids and weak piles. Before lifting, confirm the grouting equipment is stable, lift at a uniform speed, and continue grouting, observing the grouting status, matching supply and demand, and controlling the mixing effect to prepare for secondary mixing. After the drill rod is lifted to the designated position, lower it smoothly for secondary grouting to reinforce the pile. Pause again at the pile tip for additional grouting and mixing to ensure uniform pile quality. During the second lifting, grout should be sprayed at a uniform speed, controlling the rhythm, observing mixing resistance, and troubleshooting any abnormalities. After pile completion, clean up any residual grout and record the results. Construction parameters are determined based on site conditions, strictly adhering to preset standards, controlling lifting speed, cement usage, and water-cement ratio, and monitoring and recording throughout the process to ensure construction consistency.

[0034] Furthermore, in step S300, if a grouting interruption occurs during the construction of the cement mixing pile, the lifting operation is immediately stopped, the drill rod is lowered to 0.5m below the grouting interruption point, and the grouting equipment is restarted for re-grouting and re-mixing.

[0035] Grouting interruptions are often caused by blockages in the grouting pipes, insufficient cement grout supply, or equipment malfunctions. Upon discovering a grouting interruption, the drill rod lifting must be stopped immediately to prevent dry drilling, which could lead to quality defects such as broken piles or mud inclusions. The drill rod should be slowly lowered to 0.5m below the grouting interruption point, ensuring a smooth descent and avoiding sudden drops to prevent disturbance to the already mixed pile. Before restarting the grouting equipment, check the pipe patency, clear any blockages, and replenish sufficient compliant cement grout. After confirming that the grouting pressure and flow rate are normal, begin re-grouting and re-mixing. During re-grouting and re-mixing, control the drill rod lifting speed to match the original construction speed to ensure the interrupted grout area is fully filled and evenly mixed. Normal construction can only resume after re-grouting is completed. Simultaneously, record the grouting interruption time, treatment measures, and treatment effects for subsequent quality traceability.

[0036] Furthermore, in step S300, if the downtime exceeds 3 hours due to power outage or pipe blockage during the construction of cement mixing piles, the drill rod is immediately removed, the pipe is thoroughly cleaned with clean water, and after the equipment is restored to normal, the original pile foundation is continued to be constructed at the original construction location. After the original pile foundation is completed, a new pile foundation is installed at its adjacent location.

[0037] If a power outage, pipe blockage, or other abnormal situation causes the machine to be shut down for more than 3 hours, the cement slurry will solidify inside the pipe, clogging it. Furthermore, the already mixed pile slurry will begin to solidify. Continuing construction will lead to poor pile joints; therefore, the drill rod must be removed immediately. After removing the drill rod, the grouting pipe and mixing head should be repeatedly flushed with high-pressure clean water until no residual slurry remains in the pipe and the effluent is clear, preventing any solidified slurry from affecting subsequent construction. Once the equipment is back to normal, construction should resume at the original pile location to the designed pile length. After the original pile foundation is completed, a new pile foundation should be installed adjacent to it, with construction parameters identical to the original pile foundation. This is to compensate for any defects in the pile quality that may have occurred during the downtime and ensure that the roadbed bearing capacity meets design requirements. After the installation is completed, a record should be made of the installation, noting the reason for installation, location, and construction parameters.

[0038] Furthermore, in the same road soft soil treatment project, the construction process is divided according to the safe distance between the construction area and the high-voltage power tower: for conventional construction sections not restricted by the safe distance of the high-voltage power tower, the cement mixing pile process is used for soft soil treatment; for construction sections within the safe distance range of the high-voltage power tower, the high-pressure jet grouting pile process is switched to be used for soft soil treatment.

[0039] Before dividing the construction process, it is necessary to accurately define the safety distance based on relevant national standards, the voltage level of the high-voltage power tower, the tower foundation parameters, and the results of on-site surveys. Warning signs should be used to clearly demarcate the sections, and records of these demarcations should be kept. When using cement mixing pile technology in conventional construction sections, the aforementioned construction process, preset parameters, and abnormal handling requirements must be strictly followed to ensure the quality of pile formation. Within the safety distance of the high-voltage power tower, compact high-pressure jet grouting equipment should be selected to mitigate safety risks. The safety distance should be verified before construction, and construction parameters should be monitored throughout the process to ensure that both construction safety and soft soil foundation treatment quality meet the standards.

[0040] Furthermore, the construction process of the high-pressure jet grouting pile is as follows: the high-pressure jet grouting equipment is moved to the preset pile position, clean water or thin slurry is used as the drilling medium, the drilling rig is controlled to drill at a uniform speed until the designed pile bottom depth is reached, the high-pressure grouting equipment at the bottom of the hole is turned on, and the drill rod is controlled to rotate at a uniform speed and slowly lifted upward. The impact force of the high-pressure slurry is used to cut and mix the soil around the hole, so that the slurry and the soil are fully mixed, ensuring that the slurry and the soil are evenly mixed to form a continuous and complete pile body, until the drill rod is lifted to the designed elevation of the pile top, and the construction of a single high-pressure jet grouting pile is completed.

[0041] After moving the high-pressure jet grouting equipment to the preset pile position, a comprehensive inspection of the equipment is required. The pile position deviation must be calibrated, and the equipment's level and drill rod verticality adjusted to ensure stable placement and precise alignment, laying the foundation for subsequent construction. Clean water or thin slurry should be used as the drilling medium, ensuring it is clean and free of impurities to prevent clogging of the drill rod and nozzles. The medium's properties must also meet construction requirements to facilitate smooth drilling and minimize disturbance to the borehole wall soil. During the controlled uniform drilling process, the drilling status must be observed in real time, and the drilling rhythm adjusted flexibly according to the actual soil conditions. Excessive drilling speed can lead to borehole wall collapse, while excessively slow drilling can affect construction efficiency, ensuring a smooth and orderly drilling process. After drilling to the designed pile bottom depth, a pause is required to remove sediment from the bottom of the hole, ensuring a flat bottom free of debris. This provides favorable conditions for subsequent high-pressure grouting and pile formation, preventing sediment from affecting the density of the pile bottom. Before starting the high-pressure grouting equipment at the bottom of the hole, it is necessary to check the unobstructedness of the grouting pipeline and the operating status of the equipment. Only start the equipment after confirming there are no faults to ensure stable grouting pressure and avoid affecting the grouting effect due to equipment failure or pipeline blockage. When controlling the drill rod to rotate at a uniform speed and slowly lift it upwards, it is necessary to ensure that the rotation and lifting actions are coordinated and at a uniform rate, so that the high-pressure grout can be evenly sprayed onto the soil around the hole, ensuring that the grout and soil are in full contact and mixed. When using the impact force of the high-pressure grout to cut and mix the soil around the hole, the grout spraying status must be observed throughout the process to ensure that the grout is sprayed evenly and without interruption, allowing the grout to fully integrate with the soil around the hole and improving the integrity of the pile. To ensure that the grout and soil are evenly mixed to form a continuous and complete pile, the mixing effect must be carefully controlled to avoid defects such as grout separation from the soil, mud inclusions, or voids in the pile, ensuring that the pile quality meets the design requirements. After the drill rod is raised to the design elevation of the pile top, grouting should continue for a period of time to replenish the grout at the pile top, so as to avoid problems such as false piles or lack of grout at the pile top and ensure that the pile top is dense. After the construction of a single high-pressure jet grouting pile is completed, the equipment and the grout around the borehole should be cleaned in time, and construction records should be made.

[0042] Furthermore, if a grouting interruption occurs during high-pressure jet grouting pile construction, the lifting operation should be stopped immediately, the drill rod should be lowered to 0.5m below the grouting interruption point, and the jet grouting equipment should be restarted for re-jetting and re-mixing. If the downtime exceeds 3 hours due to abnormal situations such as power outages or pipe blockages during construction, the drill rod should be removed immediately, and the pipeline should be thoroughly cleaned with clean water. After the equipment is restored to normal, the original pile foundation should be supplemented at the original construction location. After the original pile foundation is completed, a new pile foundation should be installed at the adjacent location.

[0043] After the grouting is interrupted, it is necessary to first check for faults such as pipe blockage and grout supply. When lowering the drill rod, the operation should be smooth to avoid disturbing the already constructed piles. When re-grouting, the original construction parameters should be kept consistent to ensure that the grouting interruption area is filled tightly and there are no defects such as broken piles or mud inclusions. After the treatment is completed, the fault and treatment situation should be recorded to facilitate quality traceability.

[0044] If the machine is shut down for more than 3 hours, the drill rods must be removed in time, and the pipes and nozzles must be repeatedly flushed with high-pressure clean water to prevent the slurry from solidifying and clogging the equipment. New pile foundations should be installed adjacent to the original pile foundations, and the parameters of the new pile foundations should be consistent with the original pile foundations. After construction, the two pile bodies should be inspected for quality to ensure that the bearing capacity meets the standards.

[0045] Furthermore, to achieve precise control and adaptive optimization of the construction process, the construction method for soft soil subgrade with high groundwater level in fishpond areas also integrates an Internet of Things-based real-time monitoring and adaptive adjustment system for construction parameters. This system works in conjunction with cement mixing pile machine and high-pressure jet grouting pile machine to form an integrated closed-loop control unit for perception, decision-making and execution, adapting to the construction conditions of uneven soft soil and high groundwater level in fishponds, and ensuring the stability of pile quality. Specifically, data sensing and action execution devices are installed at key parts of cement mixing pile machines or high-pressure jet grouting pile machines. A torque sensor is installed at the drill rod power head to collect real-time rotational torque data reflecting changes in ground hardness; a high-precision depth encoder is installed on the winch system to acquire real-time drilling rod sinking and lifting depths; an electromagnetic flowmeter and pressure transmitter are installed on the cement slurry delivery main pipeline to monitor slurry injection flow rate and pressure in real-time; and an inclination sensor is installed on the pile frame to monitor the drill rod's verticality. Correspondingly, the pile machine's hydraulic drive system is equipped with an electro-hydraulic proportional valve for stepless adjustment of the drill rod's lifting and sinking speed, and the slurry delivery pipeline is equipped with an electric regulating valve for precise slurry flow rate adjustment. All sensors and actuators are connected to the pile machine controller via an industrial bus to achieve real-time data transmission and command issuance.

[0046] The pile driver controller or the on-site industrial computer connected to it has a preset benchmark construction parameter model and an adaptive expert rule base. The benchmark construction parameter model includes core parameters such as standard lifting speed and standard shotcrete flow rate. The expert rule base contains a series of control logics based on the construction process quality requirements of soft soil subgrade.

[0047] During the construction of cement mixing piles or high-pressure jet grouting piles, this system executes a closed-loop adaptive control process. Specifically, the sensor group collects torque, depth, flow rate, pressure, and inclination angle data in real time and transmits them synchronously to the pile driver controller, enabling real-time sensing of multiple parameters during the construction process. The pile driver controller uses depth data as a time reference, fuses and aligns multi-source monitoring data, and performs real-time comparison and analysis with the benchmark construction parameter model and expert rule base to accurately determine the deviation between the construction conditions and design requirements. Based on the comparison and analysis results, the pile driver controller generates targeted control commands; for example, when the drill bit is detected to have entered a hard soil layer, it automatically lowers and raises the hoist. The speed is increased slightly and the grouting pressure is increased to ensure the mixing and reinforcement strength of the stratum section, which is suitable for the complex strata of fishpond sections. When the instantaneous flow rate of grout is detected to be lower than the preset ratio of the design flow rate, an audible and visual alarm is immediately issued and the drill rod lifting is automatically suspended, switching to in-situ mixing mode. This triggers the abnormal handling process preset by the present invention to avoid quality defects such as grout interruption and mud inclusion. Subsequently, control commands are sent to actuators such as electro-hydraulic proportional valves and electric regulating valves to realize real-time, dynamic, and adaptive adjustment of construction parameters, ensuring that the construction process parameters are accurately matched with the stratum conditions and design requirements throughout the entire pile depth, and guaranteeing the treatment effect of soft soil subgrade.

[0048] Meanwhile, the pile driver controller uploads real-time construction data and adjustment logs to the cloud server via a wireless transmission module. The cloud platform stores and analyzes the data, displaying the "depth-torque" and "depth-flow" curves and verticality changes of each pile in the form of visual charts. The platform automatically generates a digital archive containing information such as a unique pile number, construction time, total grout volume, and key parameter curves. This digital archive serves as a traceable quality record for concealed works. When construction parameters exceed limits, the platform can send early warning information to management personnel, achieving full-process control of construction quality.

[0049] By introducing an IoT monitoring and adaptive adjustment system, this invention can intelligently sense changes in the strata and adjust construction actions in real time, effectively solving the problem of pile quality dispersion caused by the unevenness of soft soil in fishpond areas. It moves quality control from pre-acceptance of results to dynamic process assurance, significantly improving the uniformity of pile formation, overall bearing capacity and first-time pass rate of composite foundations, and adapting to the construction needs of soft soil subgrades with high groundwater levels in fishpond areas.

[0050] Those skilled in the art will readily understand that the above description is merely 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 scope of protection of the present invention.

Claims

1. A construction method for soft soil roadbed with a high groundwater level in a fishpond area, characterized in that, Includes the following steps: S100: The fishpond's fluidized silt foundation is sequentially pumped out, dredged, and replaced. After the replacement is completed, mudstone is laid to form a working platform, which is used to support the pile driver to carry out construction operations. S200: Based on the design drawings and on-site survey results, accurately lay out the pile positions on the pre-processed work platform to determine the pile positions. After marking the pile positions, conduct a verification to ensure that the pile position deviations meet the relevant specifications. S300: Move the cement mixing pile driver to the preset pile position, adjust the pile frame to a vertical state, and adopt the four-spray four-mix + pile end double stop pile forming process. Complete the spraying, stopping and lifting processes according to the preset sequence, and match the preset construction parameters to ensure that the pile body is mixed evenly and densely. S400: After the construction of a single pile is completed, repeat step S300 until the construction of all piles is completed.

2. The construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 1, characterized in that, In step S100, silt is cleared and replaced to 30cm below the designed elevation of the pile top, and then a 30cm thick mudstone is laid to form a working platform.

3. The construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 1, characterized in that, In step 200, the pile position determination is carried out using a total station for precise positioning, with a pile position deviation of no more than 5cm. The piles are marked with red and white paint. The verification is carried out using a double inspection system, with construction personnel and supervisors jointly verifying the piles. Only after the verification is qualified can the subsequent construction procedures be carried out.

4. The construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 1, characterized in that, Step S300 specifically includes: S310: As the drill rod sinks, the shotcrete equipment is started simultaneously to spray grout. After the drill rod sinks to the designed position at the pile end, it is paused for 30 seconds to ensure that the grout at the pile end is full and dense. S320: After the first stop at the pile tip is completed, the drill rod is lifted and grouting is continued to be sprayed to complete the first lifting and grouting mixing of the pile body. S330: After the drill rod is raised to the designated position, it is lowered again and grouting continues. After it is lowered to the pile end position, it is held for 30 seconds to enhance the mixing effect of the pile end and the pile body. S340: After the second stop at the pile tip, the drill rod is raised again and grouting continues to be sprayed to complete the mixing and pile forming operation of the entire pile body; The preset construction parameters are as follows: the lifting speed is controlled at 0.5 to 0.8 m / min, the cement dosage is controlled at 60 kg / m, and the water-cement ratio is controlled at 0.5 to 0.

6.

5. A construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 4, characterized in that, In step S300, if a grouting interruption occurs during the construction of cement mixing piles, the lifting operation should be stopped immediately, the drill rod should be lowered to 0.5m below the grouting interruption point, and the grouting equipment should be restarted for re-grouting and re-mixing.

6. The construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 5, characterized in that, In step S300, if the downtime exceeds 3 hours due to power outage or pipe blockage during the construction of cement mixing piles, the drill rod is immediately removed, the pipe is thoroughly cleaned with clean water, and after the equipment is restored to normal, the original pile foundation is continued to be constructed at the original construction location. After the original pile foundation is completed, a new pile foundation is installed at its adjacent location.

7. The construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 1, characterized in that, In the same soft soil foundation treatment project, the construction process is divided according to the safe distance between the construction area and the high-voltage power tower: for conventional construction sections that are not restricted by the safe distance of the high-voltage power tower, the cement mixing pile process is used for soft soil foundation treatment; for construction sections within the safe distance range of the high-voltage power tower, the high-pressure jet grouting pile process is switched to be used for soft soil foundation treatment.

8. A construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 7, characterized in that, The construction process of the high-pressure jet grouting pile is as follows: the high-pressure jet grouting equipment is moved to the preset pile position, clean water or thin slurry is used as the drilling medium, the drilling rig is controlled to drill at a uniform speed until the designed pile bottom depth is reached, the high-pressure grouting equipment at the bottom of the hole is turned on, and the drill rod is controlled to rotate at a uniform speed and slowly lifted upward. The impact force of the high-pressure slurry is used to cut and mix the soil around the hole, so that the slurry and the soil are fully mixed, ensuring that the slurry and the soil are evenly mixed to form a continuous and complete pile body, until the drill rod is lifted to the designed elevation of the pile top, and the construction of a single high-pressure jet grouting pile is completed.

9. A construction method for a soft soil roadbed with a high groundwater level in a fishpond area according to claim 8, characterized in that, If a grouting interruption occurs during high-pressure jet grouting pile construction, immediately stop the lifting operation, lower the drill rod to 0.5m below the grouting interruption point, and restart the jet grouting equipment for re-jetting and re-mixing. If the downtime exceeds 3 hours due to abnormal situations such as power outages or pipe blockages during construction, the drill rod should be removed immediately, and the pipeline should be thoroughly cleaned with clean water. After the equipment is restored to normal, the original pile foundation should be supplemented at the original construction location. After the original pile foundation is completed, a new pile foundation should be installed at the adjacent location.

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