Process for optimizing MJS construction method pile construction

Abstract

The invention discloses a technology for optimizing MJS construction method pile construction. The optimization technology comprises the steps that A, geology and environment investigation is conducted, wherein a construction scheme is formulated through geological investigation; b, monitoring point setting: monitoring the change of a soil body in the construction process; c, data analysis: determining key construction parameters based on theoretical analysis of the monitoring data, comparing the real-time monitoring data with a preset threshold value, and analyzing the stability of the soil body; d, simulation and prediction: simulating a construction process and predicting a construction result; e, process adjustment: comparing a construction simulation result with a monitoring result, and adjusting construction parameters of different construction stages; f, quality control, wherein the construction quality of the MJS pile is regularly checked and evaluated in the construction process; and G, completing evaluation: according to an evaluation result, improving the value of the construction parameter. According to the technology for optimizing MJS construction method pile construction, the soil body change caused by MJS construction method pile construction is monitored in real time, and based on the soil body change rule, the change in the soil body in the construction stage is analyzed so as to optimize the MJS construction method pile construction technology.

Description

Technical Field

[0001] This invention relates to the field of foundation engineering construction technology, and more specifically, to an optimized process for MJS method pile construction. Background Technology

[0002] In recent years, with the continuous improvement of my country's economic level, urban construction has also developed rapidly, with the height of above-ground buildings and the depth of basements constantly being refreshed. Major cities have invested heavily in the construction of underground municipal facilities such as subways and tunnels. Under these circumstances, foundation reinforcement has become an essential measure to ensure project safety and rapid construction. The Metro Jet System (MJS) high-pressure jet grouting method is based on the original high-pressure jet grouting method. It adopts a unique multi-hole pipe and a front-end forced grout suction device to achieve forced grout discharge in the borehole and monitoring of ground pressure. By adjusting the forced grout discharge volume, the ground pressure is controlled, so that the deep mud discharge and ground pressure are reasonably controlled, and the ground pressure is stabilized. This reduces the possibility of surface deformation during construction, significantly reduces the impact on the environment, and the reduction in ground pressure further ensures the pile diameter. Compared with the traditional jet grouting process, the MJS method reduces the impact of construction on the surrounding environment.

[0003] In the construction process of MJS method piles, the main reliance is on manual experience and on-site monitoring, including the following: 1. Recording monitoring data: Monitoring personnel should record monitoring data in detail, including monitoring time, monitoring point location, and monitoring value. Records should be clear and accurate for easy subsequent analysis and processing. 2. Analyzing monitoring data: Statistical analysis of the monitoring data should be conducted to identify patterns and trends in data changes. If abnormal data is found or exceeds the specified range, it should be analyzed and judged immediately to find the cause and take appropriate measures. 3. Feedback of monitoring results: Monitoring results should be promptly fed back to the construction supervisor and relevant personnel. Based on the monitoring results, construction plans and measures should be adjusted to ensure construction quality and safety. However, due to the excessive reliance on manual monitoring, which depends on the operation and experience of monitoring personnel, it is easily affected by human factors. The professional level, work attitude, and fatigue level of monitoring personnel can all affect the accuracy of monitoring results. Therefore, the existing MJS method pile construction process has the following drawbacks: For example, if the monitoring personnel operate improperly or make incorrect judgments, the monitoring data may deviate from the true value, thus affecting construction decisions. Furthermore, the monitoring efficiency during existing MJS method pile construction is relatively low. Compared to automated monitoring equipment, manual monitoring is generally less efficient. Manual monitoring requires personnel to be physically present on-site for measurement and recording, which is not only time-consuming and labor-intensive but may also affect the construction progress. In situations requiring real-time or high-frequency monitoring, manual monitoring may not meet the requirements. Secondly, the monitoring range is limited. The monitoring range of manual monitoring is usually restricted. Since monitoring personnel need to be physically present on-site, it may not be possible to cover all areas or points that need monitoring. This may lead to the omission of some important monitoring data, thus affecting the comprehensive assessment of construction quality. Thirdly, data processing and analysis capabilities are limited. The data processing and analysis capabilities of manual monitoring are relatively weak. Monitoring personnel usually need to manually record data and perform simple calculations and analyses, which may limit the accuracy and efficiency of data processing and analysis. At the same time, manual monitoring may not be able to identify and warn of potential safety hazards or quality problems in a timely manner. Finally, there is a high dependence on monitoring personnel. If the number of monitoring personnel is insufficient or their experience is lacking, it may not be able to effectively handle complex monitoring tasks. In addition, high staff turnover or lack of professional training can also affect the stability and reliability of monitoring results.

[0004] Therefore, how to solve the problems that traditional MJS method pile construction often relies on manual experience and on-site monitoring, resulting in incomplete data collection, untimely analysis, and inaccurate early warning, has become an urgent issue to be addressed in the current MJS method pile construction process. Summary of the Invention

[0005] This invention provides an optimized construction process for MJS method piles. Monitoring equipment is installed during the MJS method pile construction process to monitor in real time the soil pore water pressure, soil pressure, deep soil horizontal displacement, stratified settlement, and surface settlement caused by the construction. Based on the variation patterns of these parameters, the changes at each construction stage are analyzed, and the MJS method pile construction process is optimized.

[0006] The technical solution adopted by this invention to solve its technical problem is an optimized MJS method pile construction process. This optimized MJS method pile construction process is based on monitoring data from different construction stages of the MJS method pile, and includes the following steps:

[0007] A. Geological and Environmental Survey: Before construction, geological surveys are conducted to determine the geological structure, soil type, and groundwater level of the construction area, and a construction plan is formulated.

[0008] B. Monitoring point setup: Monitor soil settlement, soil displacement, and soil pressure during construction;

[0009] C. Data Analysis: Based on theoretical analysis of monitoring data, key construction parameters for different construction stages are determined, and real-time monitoring data are compared with preset thresholds to analyze soil stability.

[0010] D. Simulation and Prediction: Simulate the construction process and predict the construction results;

[0011] E. Process Adjustment: Compare the construction simulation results and monitoring results, and adjust the construction parameters for different construction stages;

[0012] F. Quality Control: Regular inspection and evaluation during construction. During the construction process, the quality of MJS pile construction will be regularly inspected and evaluated. The inspection and evaluation content includes pile integrity, bearing capacity and deformation parameters.

[0013] G. Complete the assessment: Based on the assessment results, improve the values ​​of the construction parameters.

[0014] Preferably, the geological exploration process in step A includes geological exploration equipment for exploration and a database for storing geological exploration data.

[0015] Preferably, the geological exploration equipment includes a ground-penetrating radar, a geological drilling rig, and a sampler. The ground-penetrating radar is used to investigate the geological structure of the construction area, the geological drilling rig is used to investigate the groundwater level information of the construction area by drilling, and the sampler is used to investigate the soil type of the construction area.

[0016] Preferably, the soil internal pressure in step B includes soil pore water pressure and soil pressure, the soil settlement includes stratified settlement and surface settlement, the soil displacement includes deep soil horizontal displacement, and the soil monitoring during construction includes a level for monitoring soil settlement, an inclinometer for monitoring soil displacement, and an internal pressure sensor and pore water pressure gauge for monitoring soil internal pressure.

[0017] Preferably, the pore water pressure gauge is installed within a range of 0.5 to 1.0 times the pile diameter from the edge of the MJS pile to monitor the pore water pressure of the soil.

[0018] Preferably, the key construction parameters in step C include grouting pressure, grouting flow rate, grouting time, drill rod lifting speed, drill rod rotation angle, mud discharge volume, and ground pressure control value.

[0019] Preferably, the method for inspecting and evaluating the construction quality of MJS piles in step F includes the low-stress fluctuation method and the high-strain dynamic pile test method. In step F, the low-stress fluctuation method and the high-strain dynamic pile test method are implemented through quality testing equipment to detect the integrity, bearing capacity and deformation parameters of the pile body during the construction of MJS piles.

[0020] Preferably, the quality testing equipment includes a low-stress fluctuation tester and a high-strain dynamic pile tester. The low-stress fluctuation tester is used to implement the low-stress fluctuation method to detect and analyze the integrity of the pile body; the high-strain dynamic pile tester is used to implement the high-strain dynamic pile test method to detect the bearing capacity and deformation of the pile body during the construction of MJS method piles.

[0021] The beneficial effects of this invention are as follows:

[0022] The present invention provides an optimized construction process for MJS method piles, which involves setting up monitoring equipment during the construction of MJS method piles to monitor in real time the soil pore water pressure, soil pressure, deep soil horizontal displacement, stratified settlement, and surface settlement caused by the construction of MJS method piles. Based on the variation law of soil pore water pressure, soil pressure, deep soil horizontal displacement, stratified settlement, and surface settlement, the mechanical changes in the construction stage are analyzed to optimize the construction process of MJS method piles.

[0023] This optimized MJS method pile construction process solves the problem that traditional MJS method pile construction often relies on manual experience and on-site monitoring, avoiding issues such as incomplete data collection, untimely analysis, and inaccurate early warning. It further improves the stability and reliability of MJS method pile construction and increases the construction efficiency of MJS method pile construction. Attached Figure Description

[0024] Figure 1This is a schematic diagram illustrating an optimized MJS method for pile construction according to the present invention. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Numerous specific details are set forth in the following description to enable those skilled in the art to fully understand the invention. However, the invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0028] In the description of the embodiments of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0030] like Figure 1 As shown, an optimized construction process for MJS method piles is proposed. This optimized construction process is based on monitoring data from different construction stages of the MJS method piles and includes the following steps:

[0031] A. Geological and Environmental Survey: Before construction, geological surveys are conducted to determine the geological structure, soil type, and groundwater level of the construction area, and a construction plan is formulated.

[0032] The geological exploration process includes geological exploration equipment and a database for storing geological exploration data. The equipment includes ground-penetrating radar, geological drilling rigs, and samplers. Ground-penetrating radar is used to investigate the geological structure of the construction area, geological drilling rigs are used to drill holes to investigate groundwater levels, and samplers are used to investigate soil types. Step A, based on the detailed geological information obtained from the geological exploration, effectively provides a scientific basis for the formulation of the construction plan, enabling construction personnel to develop appropriate plans, including pile location, pile diameter, and pile length.

[0033] B. Monitoring point setup: Monitor soil settlement, soil displacement, and soil pressure during construction;

[0034] In this embodiment, the soil pressure in step B includes pore water pressure and soil pressure; soil settlement includes stratified settlement and surface settlement; soil displacement includes horizontal displacement of deep soil; and soil monitoring during construction includes a level for monitoring soil settlement, an inclinometer for monitoring soil displacement, an in-situ pressure sensor for monitoring soil pressure, and a pore water pressure gauge. In one embodiment, the pore water pressure gauge is installed within 0.5 to 1.0 times the pile diameter from the edge of the MJS pile to monitor the pore water pressure; the in-situ pressure sensor is installed within the influence range of the MJS pile and in the deep soil; the inclinometer is installed around the foundation pit support structure to monitor the displacement of the soil around the foundation pit support structure; and the level is installed in a building adjacent to the MJS pile construction site to monitor the settlement of the soil under the building by monitoring the settlement of the building. The main parameters of the soil pore water pressure are excess pore water pressure, pore water pressure gradient, and dissipation rate. In one embodiment, the excess pore water pressure is ≤20 kPa during construction; the pore water pressure gradient is ≤2 kPa / m vertically and ≤0.5 kPa / m horizontally; and the dissipation rate is 0.1-0.5 kPa / h during the loading period and 0.05-0.2 kPa / h during the constant load period, which ensures the reinforcement effect while minimizing the impact on the surrounding environment.

[0035] C. Data Analysis: Based on theoretical analysis of monitoring data, key construction parameters for different construction stages are determined, and real-time monitoring data are compared with preset thresholds to analyze soil stability.

[0036] In this embodiment, the preset thresholds are set based on the following factors: design specifications (including maximum allowable displacement and critical pore water pressure); geological survey report (including the physical and mechanical properties of the silt layer, such as shear strength and compression modulus); and engineering experience (including safety thresholds for similar projects). In one embodiment, the preset thresholds are mainly as follows: cumulative horizontal displacement ≤ 10 mm, soil settlement rate ≤ 0.5 mm / day for 3 consecutive days; cumulative vertical displacement of surface settlement ≤ 15 mm, surface settlement rate ≤ 0.3 mm / day for 3 consecutive days; pore water pressure ≤ 20 kPa (excess pore pressure), pore water pressure dissipation rate ≥ 0.1 kPa / day; differential settlement due to deformation of adjacent buildings ≤ 10 mm, crack width of deformation of adjacent buildings ≤ 0.3 mm (new cracks); daily fluctuation range of groundwater level ≤ 0.5 m, and cumulative change of groundwater level throughout the construction process ≤ 1.0 m. Based on the comparison between real-time monitoring data and preset thresholds, key construction parameters are determined, including grouting pressure, grouting flow rate, grouting time, drill rod lifting speed, drill rod rotation angle, mud discharge volume, and ground pressure control value.

[0037] D. Simulation and Prediction: Simulate the construction process and predict the construction results;

[0038] E. Process Adjustment: Compare the construction simulation results and monitoring results, and adjust the construction parameters for different construction stages;

[0039] F. Quality Control: Regular inspection and evaluation during construction. During the construction process, the quality of MJS pile construction will be regularly inspected and evaluated. The inspection and evaluation content includes pile integrity, bearing capacity and deformation parameters.

[0040] In this embodiment, the methods for checking and evaluating the construction quality of MJS piles in step F include the low-stress fluctuation method and the high-strain dynamic pile test method. In step F, the low-stress fluctuation method and the high-strain dynamic pile test method are implemented using quality testing equipment to detect the pile integrity, bearing capacity, and deformation parameters during the construction of MJS piles. The quality testing equipment includes a low-stress fluctuation tester and a high-strain dynamic pile test machine. The low-stress fluctuation tester is used to implement the low-stress fluctuation method to analyze and judge the pile integrity; the high-strain dynamic pile test machine is used to implement the high-strain dynamic pile test method to detect the bearing capacity and deformation of the pile body during the construction of MJS piles.

[0041] G. Complete the assessment: Based on the assessment results, improve the values ​​of the construction parameters.

[0042] In this implementation, monitoring equipment is installed during the MJS method pile construction process to monitor soil changes caused by the construction in real time. By monitoring and analyzing data during construction, the system can promptly identify potential quality problems and safety hazards, providing timely early warnings and alarms to construction personnel, thereby preventing accidents and improving construction quality and safety. Furthermore, detailed geological information obtained through preliminary geological surveys provides a scientific basis for the formulation of construction plans; simultaneously, real-time monitoring provides real-time feedback of data during construction, offering real-time support for adjusting and optimizing the construction plan, ensuring its rationality and effectiveness. Moreover, this construction process employs a closed-loop management system of "monitoring → analysis → decision-making → control" to ensure the stability and safety of the silt layer reinforcement. By monitoring soil changes caused by MJS method pile construction in real time and utilizing the real-time monitoring data, key construction parameters can be adjusted in a timely manner, effectively improving the construction quality of MJS method piles.

[0043] Furthermore, in this embodiment, the low-stress fluctuation method for detecting pile integrity is categorized as follows: Class I (intact): wave velocity ≥ 4600 m / s, reflection amplitude ratio ≤ 0.08, no defective reflection, and clear pile bottom. Class II (minor defects): wave velocity 4200–4600 m / s, reflection amplitude ratio 0.08–0.25, localized minor reflection, and identifiable pile bottom. Class III (significant defects): wave velocity < 4200 m / s, reflection amplitude ratio > 0.25, strong defective reflection, and disappearance of pile bottom. When the low-stress fluctuation method detects a pile as Class III, it is considered to have significant defects and cannot continue to be used; the pile must be replaced for construction. The high-strain dynamic pile test method is used to test the bearing capacity and deformation parameters of MJS method piles during construction. If the pile integrity coefficient β ≥ 0.85, the elastic displacement threshold at the pile top ≤ 8mm, the damping coefficient J of the CASE method is uniformly taken as 0.3, and the bearing capacity safety factor KK ≥ 1.7, then the pile body of the MJS method pile is considered qualified.

[0044] In one embodiment, the present invention further includes a real-time monitoring system for monitoring the soil condition in real time during construction. The real-time monitoring system includes: a sensor network for real-time monitoring of changes in soil parameters caused by construction; and a transmission module for real-time transmission of data collected by the sensor network.

[0045] In a preferred embodiment, after the optimized MJS method pile construction process is completed, the test results of the quality testing equipment are further analyzed and judged. The key steps of this analysis and judgment are: 1. Data reliability verification: Checking the sensor installation quality and whether the hammering energy of the MJS method pile construction meets the standards, comparing multiple sets of data for the same pile to eliminate random errors; 2. Standard compliance judgment: Judging the MJS method pile construction based on the "Technical Specification for Testing of Building Foundation Piles" (JGJ106-2014); 3. Special evaluation of MJS reinforcement effect: Lateral resistance enhancement: Whether the soil resistance in the silt layer section of the high-strain data is significantly higher than that in the unreinforced area. Through the above analysis, the actual performance of the MJS-reinforced pile foundation can be comprehensively judged, providing a scientific basis for project acceptance or rectification.

[0046] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0047] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An optimized construction process for MJS method piles, wherein the optimized construction process for MJS method piles is based on monitoring data from different construction stages of the MJS method piles, characterized in that, The optimized MJS method for pile construction includes the following steps: A. Geological and Environmental Survey: Before construction, geological surveys are conducted to determine the geological structure, soil type, and groundwater level of the construction area, and a construction plan is formulated. B. Monitoring point setup: Monitor soil settlement, soil displacement, and soil internal pressure during construction, so as to monitor the impact of the MJS method pile construction process on the soil based on the soil settlement, soil displacement, and soil internal pressure. C. Data Analysis: Based on the theoretical analysis of soil monitoring data, the key construction parameters of the MJS method pile at different construction stages are determined, and the real-time soil monitoring data is compared with the preset soil change threshold during the construction process of the MJS method pile to analyze the stability of the soil. D. Simulation and Prediction: Simulate the construction process and predict the construction results; E. Process Adjustment: Compare the construction simulation results and monitoring results, and adjust the construction parameters for different construction stages; F. Quality Control: Regular inspection and evaluation during construction. During the construction process, the quality of MJS pile construction will be regularly inspected and evaluated. The inspection and evaluation content includes pile integrity, bearing capacity and deformation parameters. G. Complete the assessment: Based on the assessment results, improve the values ​​of the construction parameters.

2. The optimized MJS method pile construction process according to claim 1, characterized in that, The geological exploration process described in step A includes geological exploration equipment used for exploration and a database used to store geological exploration data.

3. The optimized MJS method pile construction process according to claim 2, characterized in that, The geological exploration equipment includes a ground-penetrating radar, a geological drilling rig, and a sampler. The ground-penetrating radar is used to investigate the geological structure of the construction area, the geological drilling rig is used to investigate the groundwater level information of the construction area by drilling, and the sampler is used to investigate the soil type of the construction area.

4. The optimized MJS method pile construction process according to claim 1, characterized in that, The soil internal pressure mentioned in step B includes soil pore water pressure and soil pressure; the soil settlement includes stratified settlement and surface settlement; the soil displacement includes deep soil horizontal displacement; and the soil monitoring during construction includes a level for monitoring soil settlement, an inclinometer for monitoring soil displacement, an internal pressure sensor for monitoring soil internal pressure, and a pore water pressure gauge.

5. The optimized MJS method pile construction process according to claim 4, characterized in that, The pore water pressure gauge is installed within a range of 0.5 to 1.0 times the pile diameter from the edge of the MJS pile to monitor the pore water pressure in the soil.

6. The optimized MJS method pile construction process according to claim 1, characterized in that, The key construction parameters in step C include grouting pressure, grouting flow rate, grouting time, drill rod lifting speed, drill rod rotation angle, mud discharge volume, and ground pressure control value.

7. The optimized MJS method pile construction process according to claim 1, characterized in that, The methods for inspecting and evaluating the construction quality of MJS piles in step F include the low-stress fluctuation method and the high-strain dynamic pile test method. In step F, the low-stress fluctuation method and the high-strain dynamic pile test method are implemented through quality testing equipment to detect the integrity, bearing capacity and deformation parameters of the pile body during the construction of MJS piles.

8. The optimized MJS method pile construction process according to claim 7, characterized in that, The quality testing equipment includes a low-stress fluctuation tester and a high-strain dynamic pile tester. The low-stress fluctuation tester is used to implement the low-stress fluctuation method to detect and analyze the integrity of the pile body; the high-strain dynamic pile tester is used to implement the high-strain dynamic pile test method to detect the bearing capacity and deformation of the pile body during the construction of MJS method piles.

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