Prestressed pipe pile reinforcing construction method and system suitable for soft soil foundation

Abstract

The invention discloses a prestressed pipe pile reinforcing construction method and system suitable for a soft soil foundation, and relates to the technical field of geotechnical engineering. Comprising the steps that S1, initial parameters and strategies are obtained, and geological parameters, underground water level conditions and prestressed pipe pile design parameters of a soft soil foundation are obtained; an initial foundation reinforcement model is constructed based on the parameters, and an initial pile sinking strategy is generated and comprises pile position arrangement, a pile sinking sequence and a predicted bearing capacity target; and S2, real-time pile sinking and sensing. According to the method, an initial foundation reinforcement model is constructed by obtaining soft soil foundation geology parameters, underground water level conditions and prestressed pipe pile design parameters, and a pile sinking strategy is generated. In the pile sinking process, the multi-dimensional sensor set is used for collecting the pile body perpendicularity, the penetration resistance and the pore water pressure response data of the soil body around the pile in real time, soft soil disturbance is effectively reduced, and temporary loss of the strength of the soil body around the pile is avoided.

Description

Technical Field

[0001] This invention relates to the field of geotechnical engineering technology, specifically to a method and system for reinforcing soft soil foundations using prestressed pipe piles. Background Technology

[0002] Soft soil, with its high compressibility, low bearing capacity, and strong rheological properties, has always been a highly challenging foundation type in geotechnical engineering, widely distributed in coastal areas, lacustrine and fluvial sedimentary plains, and reclaimed land areas. In building construction, transportation infrastructure, and energy facility construction, soft soil foundations, if not effectively reinforced, are highly susceptible to uneven settlement, structural tilting, and even instability, seriously threatening project safety and service life. Therefore, foundation reinforcement technology, as a core component in ensuring the quality of engineering construction in soft soil areas, has received considerable attention for its reliability, economy, and construction efficiency. Among these technologies, prestressed concrete pipe piles, due to their high strength, convenient construction, and stable quality, have become one of the mainstream pile types for soft soil foundation treatment.

[0003] Among them, the prestressed concrete pipe pile reinforcement construction method applicable to soft soil foundations aims to improve the overall bearing capacity of the foundation and control settlement deformation by sinking high-strength prestressed concrete pipe piles into the weak soil layer to form a composite foundation or end-bearing pile system. This method usually involves key procedures such as pile location layout, pile driving, pile splicing and connection and final pressure control. Its construction effect is highly dependent on the accurate understanding of soil characteristics, pile-soil interaction and load transfer mechanism.

[0004] Existing technologies for prestressed concrete pipe pile construction in soft soil foundations still have shortcomings: First, traditional pile driving techniques cause severe disturbance to soft soil, easily leading to a sudden increase in pore water pressure and soil remodeling, resulting in a temporary loss of soil strength around the pile and affecting the bearing capacity of the pile foundation. Second, pile splicing operations mostly use welding or mechanical connections, which makes it difficult to ensure the sealing and structural integrity of the connection nodes in soft soil environments with high water content and low strength, posing risks of corrosion and disintegration. Third, the construction process lacks real-time dynamic monitoring of pile verticality, penetration resistance, and soil response, making it difficult to achieve precise final pressure control, easily causing under-pressure or over-pressure, affecting the reinforcement effect. Finally, existing systems do not provide closed-loop feedback of geological parameters, construction parameters, and pile foundation performance, and cannot dynamically optimize construction strategies based on the variability of soft soil layers, resulting in large dispersion in reinforcement quality and a high rate of rework. These problems are particularly prominent in complex conditions such as deep soft soil, high groundwater levels, or adjacent existing structures, urgently requiring a prestressed concrete pipe pile reinforcement construction method and system that integrates precise sensing, intelligent control, and reliable connection. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a prestressed pipe pile reinforcement construction method and system suitable for soft soil foundations, solving the problems of severe soft soil disturbance, poor pile splice sealing and structural integrity, difficulty in accurate final compaction, and inability to dynamically optimize construction strategies in existing technologies.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a prestressed pipe pile reinforcement construction method applicable to soft soil foundations, comprising: S1. Obtain initial parameters and strategies, including geological parameters of the soft soil foundation, groundwater level conditions, and prestressed pipe pile design parameters; construct an initial foundation reinforcement model based on the parameters, and generate an initial pile driving strategy, including pile location layout, pile driving sequence, and expected bearing capacity target. S2. Real-time pile driving and sensing: The pile driving equipment is started to drive the first section of the prestressed pipe pile into the preset pile position. The equipment includes a penetration pressure adjustment module and a multi-dimensional sensor group. During the pile driving process, the multi-dimensional sensor group is used to collect real-time data on pile verticality, penetration resistance and pore water pressure response of the soil around the pile. S3. Intelligent pile connection and evaluation: After the first pile section is driven to a preset depth, the second pile section is connected by a seamless pre-tightening connection mechanism. The mechanism achieves the connection between the piles through mechanical locking and elastic sealing. During the connection process, the pre-tightening force, sealing performance and structural integrity parameters of the connection node are monitored in real time to obtain the connection quality evaluation results. S4. Precise final pressure and verification: Based on the real-time collected data and the connection quality assessment results, the penetration pressure is dynamically adjusted through the penetration pressure adjustment module; when the penetration resistance reaches the preset final pressure standard or the settlement rate meets the requirements, the pile driving is terminated; on-site testing of the pile foundation bearing capacity is carried out to obtain the actual bearing capacity and to verify the final pressure. S5. Closed-loop optimization and updating: Integrate and analyze the geological parameters, construction parameters, and pile foundation performance parameters to construct a construction effect feedback model; Based on the feedback model, dynamically adjust the initial foundation reinforcement model and optimize subsequent pile driving strategies and parameters, including penetration pressure curves, pile splicing depths, and final pressure standards.

[0007] Furthermore, the acquired geological parameters, groundwater level conditions, and prestressed pipe pile design parameters include: The physical and mechanical properties, distribution, and thickness of the soil layers are obtained through geological exploration reports; the depth of groundwater level and permeability coefficient are obtained through hydrogeological data; and the strength grade and wall thickness of prestressed pipe piles are obtained through design drawings.

[0008] Furthermore, the multidimensional sensor array includes: Inclination sensors are used to monitor the verticality of the pile; pressure sensors are used to monitor penetration resistance; and pore water pressure sensors are used to monitor the pore water pressure response of the soil around the pile.

[0009] Furthermore, the seamless pre-tightening connection mechanism includes: A sleeve connector is fitted onto the connecting ends of the upper and lower pile sections; a pre-tightening bolt is used to fix the sleeve connector; and an elastic sealing ring is used to seal the connection node.

[0010] Furthermore, the real-time monitoring of connection node preload, sealing performance, and structural integrity parameters, and the preliminary assessment, include: Preload is detected by pressure sensors; sealing condition is detected by acoustic or optical sensors; and structural stability is assessed by vibration sensors.

[0011] Furthermore, the dynamic adjustment of the penetration pressure via the penetration pressure adjustment module includes: When the detected penetration resistance is lower than the preset threshold, the penetration pressure is increased; when the penetration resistance is higher than the preset threshold or the verticality deviation of the pile exceeds the allowable range, the penetration pressure is reduced or the pile driving is suspended for correction.

[0012] Furthermore, the preset final pressure standard includes: The pile end resistance reaches the critical value required by the design bearing capacity; or the settlement per unit time of the pile body is less than the preset stable settlement rate threshold; or the rebound at the pile top meets the design specifications.

[0013] Furthermore, the construction effect feedback model includes: Establish a database of mapping relationships between geological parameters, pile driving parameters, connection quality, and pile bearing capacity; analyze historical data using machine learning algorithms, train and optimize the feedback model to predict the optimal pile driving parameters.

[0014] Furthermore, the dynamic adjustment of the initial foundation reinforcement model and optimization of subsequent pile driving strategies and parameters include: Based on the analysis results of the construction effect feedback model, the subsequent pile location layout plan or pile driving depth is revised; based on the deviation between the actual bearing capacity and the expected bearing capacity target, the expected penetration pressure curve or final pressure standard of the subsequent piles is dynamically adjusted.

[0015] The present invention also provides a prestressed pipe pile reinforcement construction system suitable for soft soil foundations, applied to any of the above-described prestressed pipe pile reinforcement construction methods for soft soil foundations, comprising: The data processing and strategy generation module is used to acquire geological parameters, groundwater level conditions and prestressed pipe pile design parameters, and generate an initial pile driving strategy based on the parameters. The pile driving sensing and control module is used to drive the pile driving equipment to drive the prestressed pipe pile into the preset pile position, and to collect data on pile verticality, penetration resistance and pore water pressure response of the soil around the pile in real time during the pile driving process, and to dynamically adjust the penetration pressure according to the collected data to achieve precise final pressure. The intelligent pile splicing and evaluation module is used to connect prestressed pipe pile segments using a seamless pre-tightening connection mechanism, and to conduct preliminary evaluation by monitoring the pre-tightening force, sealing performance and structural integrity parameters of the connection nodes in real time during the connection process. The construction optimization feedback module is used to integrate and analyze geological parameters, construction parameters, and pile foundation performance parameters, and optimize the pile driving strategy and parameters for subsequent pile locations based on the analysis results.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention constructs an initial foundation reinforcement model and generates a pile driving strategy by acquiring geological parameters of soft soil, groundwater level conditions, and prestressed pipe pile design parameters. During pile driving, a multi-dimensional sensor group is used to collect real-time data on pile verticality, penetration resistance, and pore water pressure response of the surrounding soil, effectively reducing soft soil disturbance and preventing temporary loss of soil strength. A seamless pre-tightening connection mechanism is used to connect the piles through mechanical locking and elastic sealing, while monitoring connection node parameters to improve joint sealing and structural integrity and reduce the risk of corrosion and disconnection. The penetration pressure adjustment module dynamically adjusts the penetration pressure based on real-time data, and combines a preset final pressure standard with on-site pile bearing capacity testing to achieve precise final pressure and avoid under-pressure or over-pressure. By integrating geological parameters, construction parameters, and pile performance parameters, a construction effect feedback model is constructed to dynamically adjust the initial model and optimize subsequent pile driving strategies, reducing reinforcement quality dispersion and repetitive construction. Ultimately, this significantly improves the reinforcement quality and stability of soft soil foundations and can better adapt to complex conditions such as deep soft soil and high groundwater levels. Attached Figure Description

[0017] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a system structure diagram of the present invention. Detailed Implementation

[0018] 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.

[0019] Please see Figure 1 This invention provides a method for reinforcing soft soil foundations using prestressed pipe piles, comprising: S1. Obtain initial parameters and strategies, including geological parameters of soft soil foundation, groundwater level conditions, and prestressed pipe pile design parameters; construct an initial foundation reinforcement model based on the parameters, and generate an initial pile driving strategy, including pile location layout, pile driving sequence, and expected bearing capacity target. S2. Real-time pile driving and sensing: The pile driving equipment is started to drive the first section of the prestressed pipe pile into the preset pile position. The equipment includes a penetration pressure adjustment module and a multi-dimensional sensor group. During the pile driving process, the multi-dimensional sensor group is used to collect real-time data on pile verticality, penetration resistance and pore water pressure response of the soil around the pile. S3. Intelligent pile connection and evaluation: After the first pile section is driven to the preset depth, the second pile section is connected by a seamless pre-tightening connection mechanism. The mechanism achieves the connection between the piles through mechanical locking and elastic sealing. During the connection process, the pre-tightening force, sealing performance and structural integrity parameters of the connection node are monitored in real time to obtain the connection quality evaluation results. S4. Precise final pressure and verification: Based on real-time data collection and connection quality assessment results, the penetration pressure is dynamically adjusted through the penetration pressure adjustment module; when the penetration resistance reaches the preset final pressure standard or the settlement rate meets the requirements, the pile driving is terminated; on-site testing of the pile foundation bearing capacity is conducted to obtain the actual bearing capacity and the final pressure is verified. S5. Closed-loop optimization and updating integrates and analyzes geological parameters, construction parameters, and pile foundation performance parameters to construct a construction effect feedback model. Based on the feedback model, the initial foundation reinforcement model is dynamically adjusted to optimize subsequent pile driving strategies and parameters, including penetration pressure curves, pile splicing depth, and final pressure standards.

[0020] Specifically, when carrying out prestressed concrete pipe pile reinforcement construction on soft soil foundations, the first step is to obtain initial parameters and strategies. By collecting detailed geological exploration reports of the project area, the physical and mechanical properties of the soft soil foundation, such as soil cohesion, internal friction angle, and compression modulus, are extracted to clarify the distribution range and thickness of different soil layers. Hydrogeological surveys are used to determine the groundwater level depth and soil permeability coefficient. Simultaneously, based on engineering design drawings, the design parameters such as the strength grade and wall thickness of the prestressed concrete pipe piles are determined. Based on these parameters, an initial foundation reinforcement model is constructed using finite element analysis software. Combining the deformation characteristics of the soft soil foundation with the stress law of the pipe piles, an initial pile driving strategy is generated. The pile placement fully considers the differences in soil bearing capacity, avoiding excessive soil disturbance caused by dense pile placement in the same area. A skip-driving method is adopted for the pile driving sequence to reduce mutual interference between adjacent pile constructions. At the same time, a target bearing capacity that meets the project requirements is set.

[0021] Start the pile driving equipment to drive the first section of the prestressed pipe pile into the preset pile position. The equipment is equipped with a penetration pressure adjustment module and a multi-dimensional sensor group. During the pile driving process, the multi-dimensional sensor group continuously operates. Among them, the tilt sensors are installed in the upper and middle parts of the pile body to collect the inclination data of the pile body in real time to monitor the verticality; the pressure sensors are installed at the contact part between the pile top and the pile driving equipment to dynamically capture the changes in penetration resistance; the pore water pressure sensors are buried at a distance of 1-2 times the pile diameter around the pile to record the pore water pressure response of the soil around the pile. These data are transmitted to the control terminal in real time through the wireless transmission module, facilitating the construction personnel to grasp the pile driving state in real time.

[0022] When the first section of the pile body sinks to the preset depth, such as 1 / 3 of the designed pile length, use a weldless pre-tightening connection mechanism to connect the second section of the pile body. First, sleeve the steel sleeve connector on the connecting ends of the upper and lower sections of the pile body, place an elastic sealing ring at the contact between the inner side of the sleeve and the pile body, and then fix the sleeve through the pre-tightening bolts. During the connection process, monitor the pre-tightening force, sealing performance and structural integrity parameters of the connection node in real time. Detect the pre-tightening force through the pressure sensor, detect the sealing state through the acoustic sensor, and evaluate the structural stability through the vibration sensor to form an evaluation result of the connection quality.

[0023] After completing the pile connection, combine the real-time collected pile driving data with the connection quality evaluation result, and dynamically adjust the penetration pressure through the penetration pressure adjustment module. The adjustment basis is shown in formula (1): ; where P is the adjusted penetration pressure; is the current penetration pressure; is the normalized penetration resistance deviation, , f is the actual penetration resistance, is the preset threshold of penetration resistance, and through processing, make the dimensions of the penetration resistance deviation and the verticality deviation consistent; is the normalized verticality deviation, , θ is the actual verticality deviation of the pile body, is the allowable deviation of the pile body verticality; k1 and k2 are weight coefficients, which are determined by the analytic hierarchy process. Invite 5-8 geotechnical engineering experts to score the importance of penetration resistance control and verticality control on a scale of 1-9, construct a judgment matrix to calculate the weights and conduct a consistency test. Usually, take k1 = 0.6 and k2 = 0.4. If f < f0, after substituting into formula (1), P > P0, appropriately increase the penetration pressure to ensure the pile driving efficiency; if f > f0 or θ > θ0, after substituting into formula (1), P < P0, reduce the penetration pressure; if If it exceeds 0.2, that is, the verticality deviation exceeds 20% of the allowable value, stop pile sinking, and use the equipment's deviation correction mechanism to adjust the pile body posture. When the penetration resistance reaches the preset final pressure standard and the settlement rate meets the requirements, stop pile sinking. Subsequently, conduct an on-site test of the pile foundation bearing capacity using a static load test to obtain the actual bearing capacity F actual, and compare it with the predicted bearing capacity F in the construction effect feedback model to complete the final pressure verification.

[0024] Finally, integrate construction parameters such as geological parameters, pile sinking pressure, and pile sinking speed during the construction process, as well as performance parameters such as the bearing capacity of the pile foundation, to establish a database. Analyze the data through machine learning algorithms to construct a construction effect feedback model. The core is the prediction relationship of the pile foundation bearing capacity, as shown in Formula (2): ; Among them, F is the predicted actual bearing capacity of the pile foundation; a, b, and c are regression coefficients obtained by fitting the database data using the least squares method. Taking the average penetration pressure p, pile sinking depth h, and compression modulus E of the pile tip soil layer as independent variables and F as the dependent variable, construct an error function and find the partial derivatives to solve the equation to determine the coefficients; p is the average penetration pressure during pile sinking; h is the pile sinking depth; E is the compression modulus of the pile tip soil layer, which is extracted from the geological parameters. Dynamically adjust the initial foundation reinforcement model based on the analysis results of Formula (2). For example, if F actual < F in a certain area and the difference exceeds 10%, the pile spacing can be appropriately reduced for subsequent pile position layout, or substitute it into Formula (1) to adjust the penetration pressure curve, pile splicing depth, and final pressure standard to achieve the closed-loop optimization of the construction strategy.

[0025] In this embodiment, the obtained geological parameters, groundwater level conditions, and prestressed pipe pile design parameters include: Obtain the physical and mechanical properties, distribution, and thickness of the soil layer through the geological exploration report; obtain the buried depth and permeability coefficient of the groundwater level through the hydrogeological data; obtain the strength grade and wall thickness of the prestressed pipe pile through the design drawings.

[0026] Specifically, when acquiring geological parameters, the physical and mechanical properties of the soil layers are extracted from the geological exploration report, including key indicators such as cohesion, internal friction angle, and compression modulus of each soil layer. Simultaneously, the horizontal distribution range and vertical thickness of different soil layers are clarified, providing a basis for judging the soil layer bearing capacity, the preset threshold f0 for penetration resistance, and the compression modulus E of the soil layer at the pile tip. When acquiring groundwater level conditions, the groundwater depth is determined by combining borehole water level monitoring data from hydrogeological data. The soil permeability coefficient is obtained through indoor permeability tests or field pumping tests to clarify the groundwater permeability law and avoid adverse effects of groundwater on the pile driving process and pressure adjustment. When acquiring prestressed pipe pile design parameters, the strength grade, outer diameter, and wall thickness of the pipe piles are determined based on the engineering design drawings to ensure that the performance of the pipe piles themselves meets the bearing capacity transfer requirements and guarantees the rationality of subsequent construction stages. This implementation method ensures the accuracy and comprehensiveness of initial parameter acquisition, providing reliable data support for subsequent model construction and strategy generation.

[0027] In this embodiment, the multidimensional sensor group includes: Inclination sensors are used to monitor the verticality of the pile; pressure sensors are used to monitor penetration resistance; and pore water pressure sensors are used to monitor the pore water pressure response of the soil around the pile.

[0028] Specifically, in the multi-dimensional sensor group, the tilt sensor uses a dual-axis tilt sensor with a measurement accuracy of 0.1°, which can meet the needs of monitoring the verticality of the pile during pile driving in soft soil foundations. During installation, it is fixed in an unobstructed position in the upper middle part of the pile to capture changes in the pile's tilt angle in real time to obtain the actual verticality deviation θ, and promptly detect any tendency for pile tilting. The pressure sensor uses a piezoelectric pressure sensor with a response speed of less than 1ms and a measurement range of 0-50MPa. It is installed at the contact interface between the pile top and the pile driving equipment to directly sense the pressure applied by the equipment during pile driving and convert it into actual penetration resistance f. The pore water pressure sensor uses a vibrating wire pore water pressure sensor with a measurement accuracy of ±0.5kPa. Before pile construction, it is drilled and installed at a distance of 1-2 times the pile diameter around the pile to accurately monitor changes in pore water pressure in the soil around the pile caused by pile driving disturbance, providing auxiliary basis for judging soil stability and adjusting penetration pressure. This implementation method can achieve real-time and accurate monitoring of key pile driving parameters, providing timely data support for pile driving process control and reducing quality risks caused by abnormal pile driving conditions.

[0029] In this embodiment, the weldless pre-tightening connection mechanism includes: Sleeve connector, which is fitted onto the connecting ends of the upper and lower pile sections; pre-tightening bolt, which is used to fix the sleeve connector; elastic sealing ring, which is used to achieve sealing of the connection node.

[0030] Specifically, in the seamless pre-tightening connection mechanism, the sleeve connector is made of Q355 steel, which has a yield strength ≥345MPa and can withstand the load transmitted by the pile. The inner diameter of the sleeve is 2-3mm larger than the outer diameter of the pile to ensure that the upper and lower pile sections can be smoothly inserted into the sleeve. The pre-tightening bolts are 8.8 grade high-strength bolts, with specifications determined according to the diameter of the pipe pile, to ensure that the bolts can provide sufficient pre-tightening force and prevent the connection joint from loosening during the load transfer process. The elastic sealing ring is made of nitrile rubber with a Shore hardness of 50-60, which has good elasticity and corrosion resistance. The cross-section is designed as an O-type to tightly fit the gap between the sleeve and the pile, preventing groundwater seepage and joint corrosion. During installation, first clean the top of the lower pile section, put on the sleeve, place the elastic sealing ring in the groove inside the sleeve, then align the upper pile section with the lower pile section and insert it into the sleeve. Finally, tighten the pre-tightening bolts with a wrench to complete the pile connection. This implementation method avoids the welding defects that are prone to occur in traditional welding connections. By combining mechanical locking with elastic sealing, it improves the firmness and sealing of the pile connection and reduces the risk of corrosion and disengagement at the pile connection nodes.

[0031] In this embodiment, the preload, sealing performance, and structural integrity parameters of the connection nodes are monitored in real time, and a preliminary assessment is performed, including: Preload is detected by pressure sensors; sealing condition is detected by acoustic or optical sensors; and structural stability is assessed by vibration sensors.

[0032] Specifically, during real-time monitoring of connection node parameters, a miniature pressure sensor is installed at the end of the pre-tightening bolt. The sensor is connected to a data acquisition terminal to collect bolt pre-tightening force data in real time. If the pre-tightening force does not meet design requirements, such as being lower than 90% of the design value, it is tightened promptly to ensure the connection node can transmit load-bearing capacity. An ultrasonic sensor is used as the acoustic sensor, attached to the outside of the sleeve, emitting a 50kHz ultrasonic signal to the connection node. If there is a gap in the seal, the ultrasonic signal will leak. The sealing status is judged by monitoring the signal attenuation. When the attenuation exceeds 10%, the seal is deemed unqualified, and the sealing ring is reinstalled. An accelerometer is installed in the middle of the sleeve as a vibration sensor to collect the vibration frequency and amplitude of the connection node under slight external disturbances. If the connection node structure is unstable, the vibration frequency will deviate from the design value; for example, if the design vibration frequency is 20Hz, the actual deviation may exceed 2Hz, which is used to assess structural integrity. Through multi-dimensional monitoring and comprehensive data analysis, a connection quality assessment result is formed. If the assessment result is unsatisfactory, the connection method is adjusted or the connection components are replaced promptly.

[0033] In this embodiment, the penetration pressure is dynamically adjusted by the penetration pressure adjustment module, including: When the monitored penetration resistance is lower than the preset threshold, the penetration pressure is increased; when the penetration resistance is higher than the preset threshold or the deviation of the pile body垂直度 exceeds the allowable range, the penetration pressure is decreased or the pile sinking is suspended for deviation correction.

[0034] Specifically, before dynamically adjusting the penetration pressure through the penetration pressure adjustment module, first calculate the preset threshold f0 of the penetration resistance at different pile sinking stages according to the geological parameters of the soft soil foundation and the pipe pile design parameters, and at the same time determine the allowable deviation θ0 of the pile body垂直度, which is set to 0.5% according to the "Technical Code for Building Pile Foundations". During the pile sinking process, based on the actually measured penetration resistance f and the actual垂直度 deviation θ collected in real time, use formula (1) to calculate the adjusted penetration pressure P: ; Where P is the adjusted penetration pressure; is the current penetration pressure; is the normalized penetration resistance deviation, , f is the actually measured penetration resistance, is the preset threshold of the penetration resistance, and through processing, the dimensions of the penetration resistance deviation and the垂直度 deviation are made consistent; is the normalized垂直度 deviation, , θ is the actual垂直度 deviation of the pile body, is the allowable deviation of the pile body垂直度; k1 and k2 are weight coefficients, which are determined by the analytic hierarchy process. Invite 5-8 geotechnical engineering experts to score the importance of penetration resistance control and垂直度 control on a scale of 1-9, construct a judgment matrix to calculate the weights and conduct a consistency test, and determine that k1 = 0.6 and k2 = 0.4.

[0035] If it is monitored that f < f0, after substituting into formula (1), P > P0, and the penetration pressure is appropriately increased to ensure the pile sinking efficiency; if f > f0 or θ > θ0, after substituting into formula (1), P < P0, and the penetration pressure is decreased; if exceeds 0.2, that is, the垂直度 deviation exceeds the allowable value by 20%, the pile sinking is suspended, and the pile body attitude is adjusted using the equipment deviation correction mechanism. After θ drops within the range of θ0, the pile sinking is continued. This implementation method can achieve precise control of the pile sinking pressure, avoid underpressure or overpressure situations, and at the same time ensure the垂直度 of the pile body and improve the quality of the pile sinking construction.

[0036] In this embodiment, the preset final pressure standard includes: The end resistance reaches the critical value required by the design bearing capacity; or, the settlement amount of the pile body per unit time is less than the preset stable settlement rate threshold; or, the pile top rebound amount meets the requirements of the design code.

[0037] Specifically, when setting the final pressure standard, the critical value of the pile end resistance is calculated based on the pile foundation bearing capacity requirements of the engineering design and combined with geological parameters. That is, the final pressure value of f0 in formula (1). For example, when the design bearing capacity is 2000kN, the critical value of the pile end resistance is set to 1800kN to ensure that the pile end can provide sufficient support. Referring to the settlement characteristics of soft soil foundation, a stable settlement rate threshold of the pile body settlement per unit time is set, such as 1mm / min. When the settlement rate is lower than this threshold, it indicates that the pile body has basically stabilized. Based on the elastic characteristics of prestressed pipe piles, the allowable range of the pile top rebound is determined. For example, the rebound amount is <5mm to avoid the excessive rebound amount affecting the long-term stability of the pile foundation. During the pile driving process, the pile end resistance is monitored by a pressure sensor, and the pile body settlement rate and the pile top rebound amount are monitored by a displacement gauge. When any index reaches the preset final pressure standard, the pile driving can be terminated. This implementation method can accurately determine the timing of pile driving termination, ensure that the pile foundation bearing capacity meets the design requirements, and avoid excessive pile driving that would cause resource waste or pile damage.

[0038] In this embodiment, a construction effect feedback model is constructed, including: Establish a database of mapping relationships between geological parameters, pile driving parameters, connection quality, and pile bearing capacity; analyze historical data using machine learning algorithms, train and optimize the feedback model to predict the optimal pile driving parameters.

[0039] Specifically, when constructing the construction effect feedback model, the geological parameters during the project construction process are first collected, such as the compression modulus of the soil layer at the pile tip; pile driving parameters, such as the average penetration pressure and pile driving depth; and pile splicing quality inspection data, such as the pre-tightening force and pile foundation bearing capacity test results. At the same time, relevant data from previous similar soft soil foundation prestressed pipe pile reinforcement projects are integrated to establish a database of mapping relationships between geological parameters, pile driving parameters, connection quality, and pile foundation bearing capacity. A linear regression model is used to construct the bearing capacity prediction relationship, and its expression is shown in formula (2): ; Where F is the predicted actual bearing capacity of the pile foundation; a, b, and c are regression coefficients obtained by fitting data from the database using the least squares method, with p, h, and E as independent variables and F as the dependent variable, an error function is constructed. Take the partial derivatives of a, b, and c respectively and set the partial derivatives to 0. Solve the system of equations to obtain the coefficient values. For example, after fitting, we get a=0.3, b=5, and c=2. p is the average penetration pressure during the pile driving process; h is the pile driving depth; E is the compression modulus of the soil layer at the pile tip, which is extracted from the geological exploration report. For example, E=8MPa for silty clay layer.

[0040] 70% of the data in the database is used as the training set and substituted into formula (2) to optimize the coefficients a, b, and c. 30% of the data is used as the validation set to test the model prediction accuracy. When the prediction error is less than 5%, the final construction effect feedback model is determined and the optimal pile driving parameters are predicted by this model.

[0041] In this embodiment, the initial foundation reinforcement model is dynamically adjusted and the pile driving strategy and parameters for subsequent pile locations are optimized, including: Based on the analysis results of the construction effect feedback model, the subsequent pile location layout plan or pile driving depth is revised; based on the deviation between the actual bearing capacity and the expected bearing capacity target, the expected penetration pressure curve or final pressure standard of the subsequent piles is dynamically adjusted.

[0042] Specifically, when dynamically adjusting the initial foundation reinforcement model and optimizing the subsequent pile driving strategy, the predicted bearing capacity F output by the construction effect feedback model is first analyzed using formula (2). If the actual bearing capacity F of the pile foundation after construction in a certain area is lower than F and F<0.9, combined with geological parameters, such as the small compression modulus E of the soil layer at the pile tip, the subsequent pile layout scheme is modified, and the pile spacing is appropriately reduced, such as from 2.5m to 2.2m to enhance the overall bearing capacity of the foundation, or the pile driving depth h is adjusted. Substituting h into formula (2), if h increases by 5... If the predicted value of F increases by 8% when the initial penetration pressure is %, the subsequent pile driving depth will be increased by 5%. If the model analysis shows that the penetration pressure curve is unreasonable, such as when the initial penetration pressure P0 is used for construction, the fluctuation of P calculated by formula (1) exceeds 10%. According to the actual geological conditions, such as in soft soil areas with a smaller E, the expected penetration pressure curve of the subsequent piles will be adjusted. For example, the initial P0 will be increased by 10%, and the formula (1) will be substituted to make the P adjustment more stable. If the final pressure standard is set too high, the penetration resistance preset threshold f0 will be appropriately reduced by combining the comparison results of F and F in formula (2). This implementation method can dynamically optimize the strategy according to the actual construction situation, making the subsequent construction more adaptable to the variability of soft soil foundation, reducing repeated construction, and improving the overall reinforcement effect.

[0043] Please see Figure 2 The present invention also provides a prestressed pipe pile reinforcement construction system suitable for soft soil foundations, applicable to any of the above-mentioned prestressed pipe pile reinforcement construction methods for soft soil foundations, comprising: The data processing and strategy generation module is used to acquire geological parameters, groundwater level conditions and prestressed pipe pile design parameters, and generate an initial pile driving strategy based on the parameters. The pile driving sensing and control module is used to drive the pile driving equipment to drive the prestressed pipe pile into the preset pile position, and to collect data on pile verticality, penetration resistance and pore water pressure response of the soil around the pile in real time during the pile driving process, and to dynamically adjust the penetration pressure according to the collected data to achieve precise final pressure. The intelligent pile splicing and evaluation module is used to connect prestressed pipe pile segments using a seamless pre-tightening connection mechanism, and to conduct preliminary evaluation by monitoring the pre-tightening force, sealing performance and structural integrity parameters of the connection nodes in real time during the connection process. The construction optimization feedback module is used to integrate and analyze geological parameters, construction parameters, and pile foundation performance parameters, and optimize the pile driving strategy and parameters for subsequent pile locations based on the analysis results.

[0044] Specifically, the data processing and strategy generation module is equipped with professional data processing software. It receives data from geological exploration reports, hydrogeological data and design drawings through a data interface, automatically extracts geological parameters, groundwater level conditions and prestressed pipe pile design parameters, uses the built-in finite element analysis module to build an initial foundation reinforcement model, generates an initial pile driving strategy by combining it with an engineering experience database, and transmits the strategy to other modules.

[0045] The pile driving perception and control module includes a hydraulic drive unit and a data acquisition unit. The hydraulic drive unit is connected to the pile driving equipment and drives the equipment to drive the prestressed pipe pile into the preset pile position according to the initial pile driving strategy. The data acquisition unit is connected to the multi-dimensional sensor group and collects the actual penetration resistance, actual pile verticality deviation and pore water pressure response data of the soil around the pile in real time. The data is transmitted to the control unit. The control unit substitutes the data into the formula (1) to calculate the adjusted penetration pressure P. The output pressure of the hydraulic drive unit is dynamically adjusted by the penetration pressure adjustment unit to achieve accurate final pressure.

[0046] The intelligent pile splicing and evaluation module is equipped with a mechanical control unit and a monitoring unit. The mechanical control unit controls the action of the seamless pre-tightening connection mechanism to complete the pile splicing operations such as sleeve installation and bolt tightening. The monitoring unit is connected to pressure sensors, acoustic sensors and vibration sensors to collect the pre-tightening force, sealing status and structural integrity parameters of the connection node in real time. The data is analyzed through the built-in evaluation algorithm to generate the connection quality evaluation result, ensuring that the connection node meets the load-bearing capacity transmission requirements in formula (2).

[0047] The construction optimization feedback module receives geological parameters, construction parameters, and pile foundation performance parameters through the data bus, establishes a comprehensive database, integrates and analyzes the data using the linear regression model of formula (2) built into the machine learning module, updates the construction effect feedback model, generates subsequent pile driving strategies and parameter optimization schemes based on the model analysis results, and transmits them to the data processing and strategy generation module to achieve closed-loop optimization of the system. This system realizes intelligent and integrated management and control of prestressed pipe pile reinforcement construction in soft soil foundations, improves construction efficiency and reinforcement quality, and adapts to complex soft soil foundation conditions.

[0048] In summary, this invention constructs an initial foundation reinforcement model and generates a pile driving strategy by acquiring geological parameters of soft soil, groundwater level conditions, and prestressed pipe pile design parameters. During the pile driving process, a multi-dimensional sensor group is used to collect real-time data on pile verticality, penetration resistance, and pore water pressure response of the surrounding soil, effectively reducing soft soil disturbance and preventing temporary loss of soil strength. A seamless pre-tightening connection mechanism is adopted to achieve pile connection through mechanical locking and elastic sealing, while monitoring connection node parameters to improve the sealing performance and structural integrity of the pile joint and reduce the risk of corrosion and disconnection. The penetration pressure adjustment module dynamically adjusts the penetration pressure based on real-time data, and combines the preset final pressure standard with on-site pile bearing capacity testing to achieve precise final pressure and avoid under-pressure or over-pressure. By integrating geological parameters, construction parameters, and pile performance parameters to construct a construction effect feedback model, the initial model is dynamically adjusted and subsequent pile driving strategies are optimized, reducing the dispersion of reinforcement quality and repeated construction. Ultimately, this significantly improves the reinforcement quality and stability of soft soil foundations and can better adapt to complex conditions such as deep soft soil and high groundwater levels.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover 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 process, method, article, or apparatus.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for reinforcing soft soil foundations using prestressed pipe piles, characterized in that, include: S1. Obtain initial parameters and strategies, including geological parameters of soft soil foundation, groundwater level conditions, and design parameters of prestressed pipe piles; Based on the parameters, an initial foundation reinforcement model is constructed, and an initial pile driving strategy is generated, including pile location layout, pile driving sequence and expected bearing capacity target; S2. Real-time pile driving and sensing: Start the pile driving equipment to drive the first section of the prestressed pipe pile into the preset pile position. The equipment includes a penetration pressure adjustment module and a multi-dimensional sensor group. During the pile driving process, the multi-dimensional sensor group is used to collect real-time data on pile verticality, penetration resistance, and pore water pressure response of the soil around the pile. S3. Intelligent pile connection and evaluation: After the first pile section is driven to a preset depth, the second pile section is connected by a seamless pre-tightening connection mechanism. The mechanism achieves the connection between the piles through mechanical locking and elastic sealing. During the connection process, the pre-tightening force, sealing performance and structural integrity parameters of the connection node are monitored in real time to obtain the connection quality evaluation results. S4. Precise final pressure and verification: Based on the real-time collected data and the connection quality assessment results, the penetration pressure is dynamically adjusted through the penetration pressure adjustment module; when the penetration resistance reaches the preset final pressure standard or the settlement rate meets the requirements, the pile driving is terminated. Conduct on-site tests of pile foundation bearing capacity to obtain the actual bearing capacity and perform final pressure verification; S5. Closed-loop optimization and updating: Integrate and analyze the geological parameters, construction parameters, and pile foundation performance parameters to construct a construction effect feedback model; Based on the feedback model, dynamically adjust the initial foundation reinforcement model and optimize subsequent pile driving strategies and parameters, including penetration pressure curves, pile splicing depths, and final pressure standards.

2. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The acquired geological parameters, groundwater level conditions, and prestressed pipe pile design parameters include: The physical and mechanical properties, distribution, and thickness of the soil layers are obtained through geological exploration reports; the depth of groundwater level and permeability coefficient are obtained through hydrogeological data; and the strength grade and wall thickness of prestressed pipe piles are obtained through design drawings.

3. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The multidimensional sensor group includes: Inclination sensors are used to monitor the verticality of the pile; pressure sensors are used to monitor penetration resistance; and pore water pressure sensors are used to monitor the pore water pressure response of the soil around the pile.

4. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The seamless pre-tightening connection mechanism includes: A sleeve connector is fitted onto the connecting ends of the upper and lower pile sections; a pre-tightening bolt is used to fix the sleeve connector; and an elastic sealing ring is used to seal the connection node.

5. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The real-time monitoring of connection node preload, sealing performance, and structural integrity parameters, and the preliminary assessment, include: Preload is detected by pressure sensors; sealing condition is detected by acoustic or optical sensors; and structural stability is assessed by vibration sensors.

6. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The method of dynamically adjusting the penetration pressure through the penetration pressure adjustment module includes: When the detected penetration resistance is lower than the preset threshold, the penetration pressure is increased; when the penetration resistance is higher than the preset threshold or the verticality deviation of the pile exceeds the allowable range, the penetration pressure is reduced or the pile driving is suspended for correction.

7. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The preset final pressure standard includes: The pile end resistance reaches the critical value required by the design bearing capacity; or the settlement per unit time of the pile body is less than the preset stable settlement rate threshold; or the rebound at the pile top meets the design specifications.

8. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The construction effect feedback model includes: Establish a database of mapping relationships between geological parameters, pile driving parameters, connection quality, and pile bearing capacity; analyze historical data using machine learning algorithms, train and optimize the feedback model to predict the optimal pile driving parameters.

9. The prestressed pipe pile reinforcement construction method for soft soil foundations according to claim 1, characterized in that, The dynamic adjustment of the initial foundation reinforcement model and optimization of subsequent pile driving strategies and parameters include: Based on the analysis results of the construction effect feedback model, the subsequent pile location layout plan or pile driving depth is revised; based on the deviation between the actual bearing capacity and the expected bearing capacity target, the expected penetration pressure curve or final pressure standard of the subsequent piles is dynamically adjusted.

10. A prestressed pipe pile reinforcement construction system suitable for soft soil foundations, applied to the prestressed pipe pile reinforcement construction method for soft soil foundations as described in any one of claims 1-9, characterized in that, include: The data processing and strategy generation module is used to acquire geological parameters, groundwater level conditions and prestressed pipe pile design parameters, and generate an initial pile driving strategy based on the parameters. The pile driving sensing and control module is used to drive the pile driving equipment to drive the prestressed pipe pile into the preset pile position, and to collect data on pile verticality, penetration resistance and pore water pressure response of the soil around the pile in real time during the pile driving process, and to dynamically adjust the penetration pressure according to the collected data to achieve precise final pressure. The intelligent pile splicing and evaluation module is used to connect prestressed pipe pile segments using a seamless pre-tightening connection mechanism, and to conduct preliminary evaluation by monitoring the pre-tightening force, sealing performance and structural integrity parameters of the connection nodes in real time during the connection process. The construction optimization feedback module is used to integrate and analyze geological parameters, construction parameters, and pile foundation performance parameters, and optimize the pile driving strategy and parameters for subsequent pile locations based on the analysis results.

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