Vacuum preloading combined with grid-like cement mixing wall foundation reinforcement system and method

Abstract

The application relates to the field of civil engineering and discloses a foundation reinforcement system and method of vacuum preloading combined with a grid-shaped cement mixing wall. The system comprises a grid-shaped cement mixing wall, a partitioned vacuum preloading system, a multi-dimensional real-time monitoring system and a central control module. The method comprises the following steps: based on the monitoring data, the central control module differentiates and controls the vacuum degrees of each partition through intelligent pressure regulating valves to minimize the differences in the settlement rates of the partitions; meanwhile, the module continuously diagnoses the consolidation bottleneck state, and once the diagnosis is correct, the module instructs a bypass pulse valve to implement positive pressure pulse intervention on the corresponding partition through a composite drainage node and then executes strong vacuum pumping. The application strengthens deep drainage by arranging the composite drainage node and realizes uniform settlement by partitioned dynamic control. Meanwhile, the application actively solves the consolidation bottleneck by pulse intervention. The system works in cooperation with each other, the functions are complementary, and the quality and controllability of foundation reinforcement are comprehensively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of civil engineering, in particular to a foundation reinforcement system and method of vacuum preloading combined with grid-shaped cement mixing wall. BACKGROUND

[0002] In large-scale civil engineering construction such as ports and yards, soft soil foundation treatment is a key link to ensure the safety and long-term stability of the engineering structure. Especially for the land formed by dredging, the foundation soil is mainly composed of silt, clay and sandy silt, which has the characteristics of high compressibility, low strength, high water content and uneven soil quality. If not effectively treated, it is easy to cause insufficient bearing capacity and excessive settlement, leading to deformation, cracking and even instability of the upper structure, which poses a serious threat to engineering safety.

[0003] To solve the above problems, the existing technology often uses vacuum preloading combined with cement mixing wall and other reinforcement technologies. However, such conventional combined methods still have inherent technical defects in implementation. The existing technology usually applies uniform vacuum load to the entire reinforcement area, but due to the natural unevenness of the geological characteristics of soft soil foundation in horizontal and vertical directions, this loading method cannot adapt to the actual consolidation needs of each area, often leading to significant uneven settlement, affecting the overall flatness and stability of the foundation. In addition, as the consolidation proceeds, the drainage channels inside the soil gradually compact and even clog, causing the drainage efficiency to drop sharply in the later consolidation period, and the entire reinforcement process enters a consolidation bottleneck state, which not only greatly prolongs the construction period, but also increases energy consumption.

[0004] Therefore, the present application proposes a foundation reinforcement system and method of vacuum preloading combined with grid-shaped cement mixing wall to solve the deficiencies of the prior art. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a foundation reinforcement system and method of vacuum preloading combined with grid-shaped cement mixing wall, which solves the problems of low control precision in foundation consolidation process, easy clogging of drainage channels, uneven consolidation of deep soil, and difficulty in actively handling the consolidation bottleneck.

[0006] To achieve the above purpose, the present application realizes the following technical scheme: a foundation reinforcement system of vacuum preloading combined with grid-shaped cement mixing wall, the system comprising:

[0007] a grid-shaped cement mixing wall arranged in the foundation to be reinforced, formed by a plurality of cement mixing piles interlapped to form a grid-shaped structure, wherein a composite drainage node is arranged at the intersection node of the grid-shaped cement mixing wall, and the permeability of the composite drainage node is higher than that of the remaining part of the grid-shaped cement mixing wall;

[0008] The vacuum preloading system is divided into multiple sub-zones, and each sub-zone is provided with an intelligent pressure regulating valve;

[0009] The multi-dimensional real-time monitoring system comprises a settlement observation point, a vacuum degree sensor, a lateral displacement meter and a wall stress sensor arranged in the sub-zone;

[0010] The central control module is electrically connected with the multi-dimensional real-time monitoring system and the intelligent pressure regulating valve, and is internally provided with a wall-soil cooperative deformation control model;

[0011] The central control module is used for receiving real-time monitoring data of the settlement observation point, the vacuum degree sensor, the lateral displacement meter and the wall stress sensor collected by the multi-dimensional real-time monitoring system, inputting the real-time monitoring data into the wall-soil cooperative deformation control model for analysis and operation to generate a vacuum degree regulating instruction for each sub-zone, and sending the vacuum degree regulating instruction to the intelligent pressure regulating valve to dynamically adjust the vacuum degree of each sub-zone.

[0012] Preferably, the composite guide node is integrally formed with the grid-shaped cement mixing wall through multiple ways:

[0013] During the pile construction at the intersection node position of the grid-shaped cement mixing wall, predetermined particle size and proportion of coarse aggregate are mixed into the cement slurry to form a cement-soil aggregate composite with an internal interconnected gap network;

[0014] During the pile construction at the intersection node position of the grid-shaped cement mixing wall, the cement content in the cement slurry is reduced to form a low-strength cement-soil body with a higher permeability coefficient than the standard wall body part of the grid-shaped cement mixing wall.

[0015] Preferably, the vacuum preloading system is further provided with a bypass pulse valve in each sub-zone, the bypass pulse valve is arranged in parallel with the vacuum pipeline corresponding to the sub-zone and is connected with an independent pressure source; the bypass pulse valve is electrically connected with the central control module and is used for applying a positive pressure pulse to the corresponding sub-zone according to the pulse instruction sent by the central control module.

[0016] Preferably, the specific condition for the central control module to execute the positive pressure pulse is:

[0017] When the central control module determines that the consolidation state of a sub-zone enters a consolidation bottleneck state based on the real-time monitoring data collected by the settlement observation point;

[0018] The judgment condition of the consolidation bottleneck state is that the settlement rate of the sub-zone satisfies the following formula:

[0019] ;

[0020] In the formula, S is the settlement amount measured by the settlement observation point; t is time; a preset settlement rate threshold.

[0021] Preferably, the wall-soil synergic deformation control model aims to minimize the settlement rate difference between any two sub-zones when generating the vacuum degree regulation instruction, and the objective function of the settlement rate difference is:

[0022] ;

[0023] wherein, is the settlement rate of the i-th sub-zone calculated by the central control module based on the real-time monitoring data of the settlement observation points; is the settlement rate of the j-th sub-zone calculated by the central control module based on the real-time monitoring data of the settlement observation points.

[0024] Preferably, the wall stress sensor in the multi-dimensional real-time monitoring system is a vibrating wire stress meter, the wall stress sensor is buried near the composite drainage node, and the wall stress sensor is used to monitor the stress response data of the composite drainage node when the vacuum preloading system performs dynamic adjustment of the vacuum degree or applies a positive pressure pulse, and sends the stress response data as part of the real-time monitoring data to the central control module.

[0025] The application also provides a foundation reinforcement method of the vacuum preloading combined with the grid-shaped cement mixed wall, and the method comprises the following steps:

[0026] S1, constructing a grid-shaped cement mixed wall penetrating through the soft soil layer, and forming a composite drainage node with higher permeability than the remaining part of the grid-shaped cement mixed wall at the intersection node of the grid-shaped cement mixed wall;

[0027] S2, installing a partitioned vacuum preloading system and a multi-dimensional real-time monitoring system;

[0028] S3, collecting real-time monitoring data by using the multi-dimensional real-time monitoring system, and analyzing and operating the real-time monitoring data by the central control module based on the wall-soil synergic deformation control model to generate vacuum degree regulation instructions for each sub-zone and to perform differential dynamic regulation of the vacuum degree for each sub-zone;

[0029] S4, during the differential dynamic regulation of the vacuum degree, continuously judging by the central control module whether there is a sub-zone entering the consolidation bottleneck state;

[0030] S5, when it is determined that a sub-zone enters the consolidation bottleneck state, the central control module instructs the opening of the bypass pulse valve corresponding to the sub-zone to apply a positive pressure pulse, and after the closing of the bypass pulse valve, instructs the vacuum pump of the sub-zone to perform air extraction at a power higher than the normal operating power.

[0031] Preferably, in step S1, the step of constructing the grid-shaped cement mixing wall penetrating the soft soil layer comprises the following steps:

[0032] In the process of adopting the deep mixer to spray and mix, at least one reciprocating operation of sinking and re-mixing and lifting and re-mixing is performed to improve the mixing uniformity of the cement slurry and the foundation soil.

[0033] Preferably, when the central control module dynamically regulates the vacuum degree of each subarea based on the wall-soil cooperative deformation control model, the control target for generating the vacuum degree regulation instruction is to minimize the settlement rate difference between any two subareas.

[0034] Preferably, in step S4, during the dynamic regulation of the differentiated vacuum degree, the step of continuously judging by the central control module whether there is a subarea entering the consolidation bottleneck state comprises:

[0035] The central control module comprehensively analyzes the settlement data, vacuum degree data, lateral displacement data and wall stress data collected by the multi-dimensional real-time monitoring system to determine whether there is a subarea entering the consolidation bottleneck state.

[0036] The present application provides a foundation reinforcement system and method of vacuum preloading combined with a grid-shaped cement mixing wall, which has the following advantages:

[0037] 1. The present application forms a vertical drainage main channel penetrating the soft soil layer, large in diameter and stable in structure by integrally forming a composite guide and drainage node at the intersection node of the grid-shaped cement mixing wall of the bearing structure. The composite guide and drainage node cooperates with the traditional plastic drainage board to form a three-dimensional drainage network combining points, lines and surfaces, effectively avoiding the drainage failure problem caused by the twisting, breaking or clogging of the plastic drainage board, and ensuring the long-term unobstructed and efficient drainage path during the entire reinforcement period.

[0038] 2. The present application divides the reinforcement area into multiple independent subareas and uses a central control module, a multi-dimensional real-time monitoring system and a wall-soil cooperative deformation control model to independently, dynamically and closed-loop feedback regulate the vacuum degree of each subarea according to the real-time settlement, stress and other response data of each subarea. This differentiated regulation method replaces the one-size-fits-all overall loading mode in the traditional vacuum preloading, can accurately control the soil quality difference and consolidation response of different areas, and thus obtain more uniform foundation settlement and effectively control the lateral displacement.

[0039] 3、In view of the consolidation bottleneck problems such as settlement stagnation that are prone to occur in the later stage of traditional vacuum preloading, the application proposes a cyclic treatment method of forward pressure pulse and strong vacuum extraction. The forward pressure pulse applied through the advantage channel of the composite drainage node can actively disturb the local soil structure, break the existing soil arching effect or dredge the blocked drainage channel; the subsequent strong vacuum extraction can quickly drain the disturbed pore water that is prone to flow. This active intervention capability improves the reinforcement effect and success rate of the technical solution for deep and complex soft soil foundation.

[0040] 4、The application organically integrates the grid-shaped cement mixing wall (bearing and restraint), the composite drainage node (vertical main drainage channel) and the partitioned dynamic vacuum preloading system (intelligent control means) into a whole that works cooperatively. The grid wall provides a stable boundary and partitioned foundation for vacuum preloading, the composite drainage node improves the efficiency of drainage and pressure pulse, and the intelligent control system maximizes the functions of the former two. This system-level integrated design makes each technical link support each other and complement each other's functions, thereby improving the final quality and controllability of foundation reinforcement. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0042] Figure 1 It is a partial three-dimensional structure schematic diagram of the foundation reinforcement system of the embodiment of the application.

[0043] Figure 2 It is a partial cross-sectional schematic diagram of the foundation reinforcement system of the embodiment of the application.

[0044] Figure 3 It is an enlarged schematic diagram of A in the embodiment of the application. Figure 2

[0045] Figure 4 It is a partial top view schematic diagram of the arrangement of the foundation reinforcement system of the embodiment of the application.

[0046] Figure 5 It is a block diagram of the connection relationship between the central control module and each system component of the embodiment of the application.

[0047] Figure 6 It is a schematic diagram of the relationship between the settlement rate of a partition and the vacuum degree control of the embodiment of the application.

[0048] Figure 7 ​The schematic diagram for a certain partition of the embodiment of the application entering a consolidation bottleneck state and performing pulse intervention;

[0049] Figure 8 The process flow chart for the pre-treatment of dynamic compaction of the embodiment of the application;

[0050] Figure 9 The construction process flow chart for the cement mixing wall of the embodiment of the application.

[0051] BRIEF DESCRIPTION OF DRAWINGS

[0052] 1, grid-shaped cement mixing wall; 11, composite guide node;

[0053] 2, partitioned vacuum preloading system; 21, drainage plate; 22, vacuum main pipe; 23, vacuum branch pipe; 24, sealing film; 25, sealing shed; 26, intelligent pressure regulating valve; 27, bypass pulse valve;

[0054] 3, settlement observation point; 4, vacuum degree sensor; 5, lateral displacement meter; 6, site drainage plate; 7, wall stress sensor;

[0055] 100, central control module; 200, multi-dimensional real-time monitoring system. DETAILED DESCRIPTION

[0056] The embodiments of the application will be described in detail below with reference to the accompanying drawings.

[0057] It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict; and all other embodiments obtained by those skilled in the art based on the embodiments in the present disclosure without creative labor are within the scope of protection of the present disclosure.

[0058] It should be noted that the various aspects of the embodiments described below are within the scope of the appended claims. It should be apparent that the aspects described herein can be embodied in a wide variety of forms and that any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, one skilled in the art should appreciate that one aspect described herein can be implemented independently of any other aspects and that two or more of these aspects can be combined in various ways. For example, an apparatus can be implemented and / or a method can be practiced using any number of the aspects set forth herein. In addition, such an apparatus can be implemented and / or such a method can be practiced using other structure and / or functionality in addition to or other than one or more of the aspects set forth herein.

[0059] As Figures 1 to 5As shown, the embodiment of the present application provides a foundation reinforcement system of vacuum preloading combined with grid-shaped cement mixing wall. The system comprises: a grid-shaped cement mixing wall 1, a partitioned vacuum preloading system 2, a multi-dimensional real-time monitoring system 200 and a central control module 100. The multi-dimensional real-time monitoring system 200 is electrically connected with the central control module 100, and the central control module 100 is electrically connected with the partitioned vacuum preloading system 2.

[0060] As shown, Figure 1 and Figure 2 , the grid-shaped cement mixing wall 1 is arranged in the soft soil foundation to be reinforced in a grid shape, and the wall structure is formed by a plurality of cement mixing piles which are overlapped, for providing bearing capacity to the foundation soil body, restraining lateral deformation thereof and serving as an impermeable boundary of vacuum preloading. As shown, Figure 4 , a composite drainage node 11 is integrally formed at the intersection node of the grid-shaped cement mixing wall 1. The structure of the composite drainage node 11 makes its permeability coefficient higher than that of the standard wall body of the grid-shaped cement mixing wall 1, thereby constituting a vertical drainage main channel penetrating through the soft soil layer. The forming mode of the composite drainage node 11 includes: during the construction of the pile body at the intersection node position of the cement mixing wall, coarse aggregate of a preset particle size and proportion is mixed into the cement slurry; or during the construction of the pile body at the intersection node position, the cement content is reduced.

[0061] As shown, Figures 2 to 4 , the partitioned vacuum preloading system 2 covers the reinforcement area surrounded by the grid-shaped cement mixing wall 1. The system comprises drainage plates 21, a vacuum main pipe 22, vacuum branch pipes 23, a sealing film 24 and a sealing shed 25. The drainage plates 21 are vertically arranged in the soil body surrounded by the grid-shaped cement mixing wall 1. The vacuum branch pipes 23 are communicated with the top of the drainage plates 21, and the vacuum main pipe 22 collects a plurality of vacuum branch pipes 23. The sealing film 24 covers the ground surface, and its edge is sealingly connected with the top of the grid-shaped cement mixing wall 1. The sealing shed 25 is arranged above the sealing film 24 and the grid-shaped cement mixing wall 1. The system is divided into a plurality of independent control partitions according to the geological conditions or design requirements, and an intelligent pressure regulating valve 26 and a bypass pulse valve 27 are arranged on the vacuum pipeline of each control partition.

[0062] As shown, Figure 5 , the intelligent pressure regulating valve 26 is installed on the vacuum pipeline connected to the corresponding partition, for receiving the control signal from the central control module 100 and adjusting the vacuum degree of the partition according to the control signal. The bypass pulse valve 27 is connected with the main vacuum pipeline and connected to an external pressure source, for receiving the pulse instruction from the central control module 100 and instantaneously applying positive pressure to the partition.

[0063] As shown, Figure 5As shown, the multi-dimensional real-time monitoring system 200 is used to collect the state data during the ground reinforcement process. The system comprises a plurality of sensors arranged in the reinforcement area, which at least include: settlement observation points 3, vacuum degree sensors 4, lateral displacement meters 5, and wall stress sensors 7. The settlement observation points 3 are used to monitor the vertical settlement of each subarea of the foundation; the vacuum degree sensors 4 are used to monitor the real-time vacuum degree of each subarea; the lateral displacement meters 5 are used to monitor the lateral displacement of the grid-shaped cement mixing wall 1; and the wall stress sensors 7 are embedded in the grid-shaped cement mixing wall 1 and adjacent to the composite drainage node 11, and are used to monitor the stress change of the wall structure under the action of vacuum load and pulse pressure. As shown in Figure 3 As shown, the ground reinforcement system combining vacuum preloading and grid-shaped cement mixing wall can also comprise site drainage boards 6 for draining surface water.

[0064] The hardware of the central control module 100 can be a programmable logic controller (PLC) or an industrial control computer. The central control module 100 is pre-provided with a wall-soil collaborative deformation control model, and is in communication connection with each valve of the multi-dimensional real-time monitoring system 200 and the partitioned vacuum preloading system 2. The central control module 100 receives the real-time monitoring data from the multi-dimensional real-time monitoring system 200, performs calculation through the wall-soil collaborative deformation control model, and generates control instructions to be sent to the intelligent pressure regulating valves 26 and the bypass pulse valves 27 of each subarea.

[0065] During operation, the wall-soil collaborative deformation control model of the central control module 100 continuously receives the settlement data of each subarea, and dynamically and independently adjusts the opening degree of the intelligent pressure regulating valve 26 of each subarea to realize the differential closed-loop regulation and control of the vacuum degree of each subarea, with the control target of minimizing the difference in settlement rate of each subarea.

[0066] At the same time, the central control module 100 performs real-time diagnosis on the consolidation bottleneck state of each subarea according to the received settlement data.

[0067] When the central control module 100 determines that any subarea enters the consolidation bottleneck state, it will immediately send an opening instruction to the bypass pulse valve 27 corresponding to the subarea to apply one or more short positive pressure pulses to the deep part of the foundation through the composite drainage node 11. After the pressure pulse ends, the central control module 100 instructs the vacuum pump of the subarea to run at maximum power to perform a strong vacuum pumping operation.

[0068] As shown in Figures 1 to 3As shown, the grid-shaped cement mixing wall 1 is arranged in a grid shape in the soft soil foundation to be reinforced. The grid-shaped cement mixing wall 1 is composed of a plurality of cement mixing piles that are overlapped with each other, and functions to bear the upper load, constrain the lateral deformation of the foundation soil in the vacuum preloading process, and serve as a physical anti-seepage curtain to maintain the sealing of the vacuum preloading system. In the embodiment, the grid-shaped cement mixing wall 1 is constructed by using a land four-shaft deep mixer, the single-shaft mixing pile that constitutes the wall has a diameter of 900 mm, and the overlapping width between adjacent two piles is 200 mm, so as to form a continuous wall structure. The cement slurry used for making the mixing pile has a material composition that uses P.O42.5 ordinary portland cement, the mass ratio of water to cement, i.e. the water-cement ratio is 0.9, and the cement content in the cement-soil mixture is not less than 20%.

[0069] As shown in FIG. 1, the grid-shaped cement mixing wall 1 is arranged in a grid shape in the soft soil foundation to be reinforced. The grid-shaped cement mixing wall 1 is composed of a plurality of cement mixing piles that are overlapped with each other, and functions to bear the upper load, constrain the lateral deformation of the foundation soil in the vacuum preloading process, and serve as a physical anti-seepage curtain to maintain the sealing of the vacuum preloading system. In the embodiment, the grid-shaped cement mixing wall 1 is constructed by using a land four-shaft deep mixer, the single-shaft mixing pile that constitutes the wall has a diameter of 900 mm, and the overlapping width between adjacent two piles is 200 mm, so as to form a continuous wall structure. The cement slurry used for making the mixing pile has a material composition that uses P.O42.5 ordinary portland cement, the mass ratio of water to cement, i.e. the water-cement ratio is 0.9, and the cement content in the cement-soil mixture is not less than 20%. Figures 1 to 4 As shown, at the longitudinal and transverse wall intersection position of the grid-shaped cement mixing wall 1, a composite drainage node 11 is integrally formed. The permeability coefficient of the composite drainage node 11 is significantly higher than that of the standard wall part of the grid-shaped cement mixing wall 1, and thus it constitutes a large-diameter, structurally integrated, vertical drainage main channel that penetrates the depth of the soil layer in the soft soil layer. The specific formation method of the composite drainage node 11 includes the following two methods.

[0070] The first formation method is to add coarse aggregate with specific physical properties into the cement slurry to be injected when the grid-shaped cement mixing wall 1 is constructed at the intersection node area. Specifically, 5% to 15% of the solid mass of the slurry is mixed with bean stones or melon seed pieces with a particle size range of 5 mm to 10 mm in the standard P.O42.5 cement slurry. After forced stirring by the deep mixer, the mixed slurry forms a porous cement-soil aggregate composite with the in-situ soil. After solidification, the composite drainage node 11 is formed, and the internal connected gap network formed by the aggregate makes its permeability coefficient much higher than that of the standard wall composed of pure cement-soil.

[0071] The second formation method is to adjust the mixing ratio parameters of the cement slurry when the grid-shaped cement mixing wall 1 is constructed at the intersection node area, specifically to reduce the cement content. While keeping the water-cement ratio at 0.9, the cement content is reduced from not less than 20% of the standard wall to the interval of 8% to 12%. The composite drainage node 11 formed by using the low-content cement slurry has a lower cement-soil strength after solidification than the standard wall, but the internal pore structure is more developed, and the permeability coefficient is one to two orders of magnitude higher than that of the standard wall.

[0072] The composite drainage node 11 has a dual function in the whole foundation reinforcement system. Firstly, as a vertical drainage main channel with high permeability, its top is in fluid communication with the negative pressure area of the vacuum pipe network through the ground surface during the vacuum preloading stage, and together with the grid-distributed drainage board 21, it forms a point-line combined three-dimensional drainage network, greatly shortening the drainage path of deep pore water in the foundation and accelerating the soil consolidation process. Secondly, as a structured low-resistance channel, its top is also in fluid communication with the pressurized area of the vacuum pipe network through the ground surface during the active pulse intervention stage. When the bypass pulse valve 27 injects high-pressure gas into the vacuum pipe network, the composite drainage node 11 forms the main physical path for the transmission of pressure pulses to the deep foundation, enabling the high-pressure gas to be transmitted to the deep foundation without loss to overcome the soil arching effect or drainage channel clogging that may occur in the later stage of consolidation.

[0073] As shown in Figures 2 to 5 , the partitioned vacuum preloading system 2 is arranged in the foundation reinforcement area enclosed by the grid-shaped cement mixing wall 1. The system includes vertically arranged drainage boards 21, vacuum branch pipes 23 in communication with the top of the drainage boards 21, vacuum main pipes 22 collecting the vacuum branch pipes 23, sealing membranes 24 covering the ground surface and air-tightly connected with the grid-shaped cement mixing wall 1, and a vacuum pump set providing negative pressure for the whole pipe network system. In addition, the system can be provided with a sealing shed 25 covering the sealing membrane 24 and the grid-shaped cement mixing wall 1 to provide physical protection for the system and further enhance the air tightness.

[0074] The whole vacuum preloading system of the embodiment of the present application is partitioned. The specific implementation is that: according to the uneven soil layer distribution data obtained by foundation investigation, or according to the design requirements of the load distribution of the upper structure, the area enclosed by the grid-shaped cement mixing wall 1 is divided into multiple independent control partitions. The vacuum pipe network (including the vacuum main pipes 22 and the vacuum branch pipes 23) in each control partition forms a relatively independent subsystem, which is connected to the total vacuum pump set or the partitioned vacuum pump through its exclusive control valve set, thereby realizing independent application and control of the vacuum degree of each partition.

[0075] As shown in Figure 4 and Figure 5 , in order to realize accurate control of the vacuum degree of each partition, an intelligent pressure regulating valve 26 is installed on the vacuum main pipe 22 of each control partition. The structure of the intelligent pressure regulating valve 26 is an electric or pneumatic proportional regulating valve, and its valve body receives continuous control signals from the central control module 100, such as standard industrial current signals of 4-20 mA or digital signals based on communication protocols. The opening of the valve and the received signal value have a preset proportional relationship, and by adjusting the valve opening, the air extraction rate of the partition pipeline can be accurately controlled, thereby realizing continuous and dynamic adjustment of the vacuum degree in the foundation of the partition.

[0076] To achieve active intervention on a specific partition, a bypass pulse valve 27 is also provided on the pipeline of each control partition. The bypass pulse valve 27 is a normally closed quick-opening solenoid valve. It is installed in parallel with the vacuum main pipe 22 of the partition through a bypass pipeline, the other end of the bypass pipeline is connected to an independent pressure source, such as an air compressor or a high-pressure gas tank. The bypass pulse valve 27 receives discrete pulse instructions from the central control module 100. When receiving a discrete pulse instruction, the valve is opened instantaneously, and the high-pressure gas in the pressure source is injected into the vacuum pipe network of the partition within a preset short time, thereby applying a positive pressure pulse to the deep foundation through the composite drainage node 11. After the instruction is completed, the valve is immediately closed, and the vacuum sealing state of the partition is restored.

[0077] As shown in Figure 1 , Figure 4 and Figure 5 , the foundation reinforcement system of the embodiment of the present application includes a multi-dimensional real-time monitoring system 200. The system is used to collect various physical state parameters of the foundation during the entire reinforcement process, and transmit the collected data to the central control module 100 in real time, providing data input for subsequent closed-loop control and active intervention. The multi-dimensional real-time monitoring system 200 is composed of various sensors and data transmission components arranged inside and outside the reinforcement area.

[0078] As shown in Figure 4 , the sensors included in the multi-dimensional real-time monitoring system 200 are specifically: settlement observation points 3, vacuum degree sensors 4, and lateral displacement meters 5. The settlement observation points 3 are composed of reinforced concrete observation piles buried on the surface of the foundation, and are arranged in a grid density of one every 10 meters in each control partition. The elevation of the top of the observation pile is measured periodically by a total station or a level instrument to obtain the vertical settlement data of the foundation in each partition. The vacuum degree sensors 4 are buried at the vacuum pipeline nodes and below the sealing membrane 24 in each control partition, used to obtain the real-time vacuum degree value at the location. The lateral displacement meters 5 are installed on the outside of the grid-shaped cement mixing wall 1, used to obtain the horizontal displacement data of the wall under the action of vacuum load.

[0079] As shown in Figure 1 and Figure 5 , the multi-dimensional real-time monitoring system 200 also includes a wall stress sensor 7. The wall stress sensor 7 is selected as a vibrating wire stress meter, which is buried in the wall structure of the grid-shaped cement mixing wall 1 and is adjacent to the composite drainage node 11. Its function is to obtain the stress response data of the composite drainage node 11 at the key structural position under the action of vacuum degree change and positive pressure pulse applied by the bypass pulse valve 27. This data provides a basis for the central control module 100 to analyze the wall structure state and optimize the control model.

[0080] In terms of data acquisition and transmission, all the above-mentioned sensors (the data of the settlement observation point 3 is manually input or automatically transmitted after being collected by the measuring instrument) are connected to one or more data acquisition units through electrical signals. The data acquisition unit converts the physical signals (such as voltage, current, frequency) output by each sensor into digital signals and packages them according to the preset communication protocol. Subsequently, the data acquisition unit sends the digital information containing the real-time data of each sensor to the central control module 100 through a wired (such as RS485 industrial bus) or wireless (such as 4G or 5G cellular network) communication link.

[0081] As shown in Figure 5 , the foundation reinforcement system of the embodiment of the present application includes a central control module 100. The physical entity of the central control module 100 can be a programmable logic controller (PLC) control cabinet or an industrial control computer. The module is solidified with a software program that implements a wall-soil collaborative deformation control model for receiving data from the multi-dimensional real-time monitoring system 200 and generating control instructions for the partitioned vacuum preloading system 2.

[0082] The working logic of the wall-soil collaborative deformation control model is realized by the following modular functions:

[0083] The model includes a differential regulation logic module. During system operation, the central control module 100 continuously receives real-time settlement data from each settlement observation point 3 in the multi-dimensional real-time monitoring system 200 and uses this as input to start differential regulation. The function of this module is to generate differential control instructions for each partitioned vacuum preloading system 2 based on real-time monitoring data to achieve uniform settlement of the foundation. When generating vacuum degree regulation instructions, the target of the analysis and operation of this module is to minimize the settlement rate difference between any two regulated partitions, and the objective function of this settlement rate difference is:

[0084] ;

[0085] In the formula, is the settlement rate of region i calculated by the central control module 100 according to the real-time monitoring data of the settlement observation point 3; is the settlement rate of region j calculated by the central control module 100 according to the real-time monitoring data of the settlement observation point 3. This module continuously receives real-time settlement data from each settlement observation point 3 in the multi-dimensional real-time monitoring system 200, performs operations through the above-mentioned objective function, generates a set of independent control signals for different partitions, and sends them to the intelligent pressure regulating valve 26 corresponding to each partition, respectively, to change the vacuum extraction efficiency of each partition by adjusting the valve opening, thereby dynamically and differentially adjusting the vacuum degree in the foundation of each partition.

[0086] The model further comprises a consolidation bottleneck diagnosis logic module. The function of this module is to determine whether each control partition enters a consolidation bottleneck state of reduced drainage efficiency based on real-time settlement data. Specifically, this module continuously tracks the settlement rate of each partition over time. When the settlement rate of a partition is continuously monitored to be below a preset rate threshold for a preset period of time (for example, 24 hours), a determination condition is triggered. The determination condition is expressed by the following formula:

[0087] ;

[0088] In the formula, S is the cumulative settlement of a specific control partition, which is derived from the settlement observation point 3 in the partition, and the unit is millimeter (mm). t is time, and the unit is day (d). is the real-time settlement rate of the specific control partition, which is calculated by the central control module 100 by time derivation on the continuous settlement data S, and the unit is millimeter per day (mm / d). is a preset consolidation bottleneck state judgment threshold, which is pre-set according to the engineering properties of the soil and the final consolidation degree required by the design, for example, 1 mm / d.

[0089] The model further comprises a pulse intervention decision logic module. When the consolidation bottleneck diagnosis logic module determines that a specific partition meets the condition of , the pulse intervention decision logic module is immediately activated. The module will immediately generate one or a series of preset parameter active pulse intervention instructions, which are sent to the bypass pulse valve 27 connected in parallel on the pipeline of the partition to drive the valve to open for a set length of time (for example, 0.5 to 2 seconds) to perform an active intervention.

[0090] To further illustrate the present application, the foundation reinforcement method provided by the present application is described below in conjunction with a specific embodiment.

[0091] With reference to Figures 1 to 9 , the foundation reinforcement method of the vacuum preloading combined with the grid-shaped cement mixing wall of the embodiment of the present application is applied to the secondary reinforcement engineering of the foundation of the bucket wheel machine foundation area in a port operation area. The site is formed by hydraulic filling, the thickness of the soft soil layer is 5 to 11 meters, and the foundation soil is mainly silt, silty clay and silt, which has the characteristics of high compressibility and low strength. The purpose of implementing the method is to meet the requirements of the bucket wheel machine heavy load operation on the foundation bearing capacity and settlement control.

[0092] Step S1 (site preparation and grid-shaped cement mixing wall construction):

[0093] With reference to Figure 8 , in this embodiment, step S1 comprises the following sub-steps:

[0094] Step S81 (site leveling and cleaning), this step preliminarily processes the construction site of the bucket wheel machine foundation area, including removing sundries and loose soil layer within a depth of about 0.4 meters on the ground surface, and preliminarily leveling the site using a bulldozer or a grader to ensure that the construction area is clean and tidy, and to provide conditions for subsequent measurement and line laying work.

[0095] Step S82 (measurement and line laying, calibration of the first ramming point), this step uses a total station or a theodolite to accurately measure and lay lines, and calibrates the position of the first ramming point on the site according to the design requirements. The spacing and arrangement of the points are based on the design drawings, and the points are arranged with 1 / 4 hammer diameter overlap to ensure uniform coverage.

[0096] Step S83 (first ramming point construction), this step uses a strong ramming equipment (for example, a 20t crawler crane with a 10t circular rammer) to ram the first ramming point one by one according to the calibration. The first ramming energy is set to 600KJ, and the strong ramming impact wave is formed by the free fall of the rammer to improve the density of the shallow soil of the foundation.

[0097] Step S84 (ramming pit material supplementing and leveling), in this step, a number of ramming pits are formed after the first ramming, and materials such as gravel and graded sand are used to supplement the ramming pits, and then a road roller or a vibrating rammer is used to level the surface to eliminate the influence of uneven ramming pits on the construction accuracy of subsequent ramming.

[0098] Step S85 (measurement and line laying, calibration of the second ramming point), this step re-measures and lays lines, and calibrates the position of the second ramming point on the site according to the design requirements. The second ramming point is usually arranged in a staggered manner relative to the first ramming point to achieve full coverage.

[0099] Step S86 (second ramming point construction), this step uses the same strong ramming equipment to ram the second ramming point, and the ramming energy is increased to 1000KJ to further reinforce the soil of the foundation. The ramming points are still arranged with 1 / 4 hammer diameter overlap.

[0100] Step S87 (ramming pit material supplementing and leveling), in this step, the ramming pit material is supplemented again after the second ramming, and leveling equipment is used to level the site surface to ensure that the overall elevation meets the design requirements.

[0101] Step S88 (completion elevation measurement), after the ramming and leveling are completed, this step re-measures the site elevation using a level and other measuring equipment to confirm the consistency of the foundation flatness and the design elevation, and to ensure that the construction quality meets the standards.

[0102] Step S89 (final site leveling), if there is a deviation in the measurement results in this step, a small amount of material needs to be supplemented or trimmed to accurately level the site to the design elevation to provide a stable platform for subsequent cement mixing wall construction.

[0103] Step S90 (entering the grid-shaped cement mixing wall construction), after the foundation reinforcement and site leveling are completed, the pile arrangement and mixing construction of the grid-shaped cement mixing wall are entered, specifically including drilling, grouting, in-situ mixing and other procedures.

[0104] Figure 9 is a flow chart of the sinking and lifting and reciprocating process in the construction process of the grid-shaped cement mixing wall in the embodiment of the application. Referring to Figure 9 , the flow includes the following steps:

[0105] In step S91, after the site is subjected to dynamic compaction treatment and leveling operation, subsequent construction preparation work of the grid-shaped cement mixing wall 1 is carried out.

[0106] In step S92, a land four-axle deep mixer is used as the construction equipment, P.O42.5 ordinary portland cement is used as the main cementing material, the water-cement ratio is 0.9, and the cement content is not less than 20% to prepare the cement slurry, so as to ensure the strength and uniformity of the cement-soil pile.

[0107] In step S93, the mixer drills along the designed axis to form cement mixing piles with a pile diameter of 900 mm and a lap width of 200 mm between adjacent piles, and the overall grid-shaped cement mixing wall structure is formed by staggered arrangement.

[0108] In step S94, the sinking and lifting and reciprocating operation cycle is started, that is, the mixing head slowly sinks under the self-weight and pressure of the equipment until the preset pile bottom design elevation is reached to provide positioning for subsequent grouting.

[0109] In step S95, when the mixing head reaches the pile bottom elevation, the cement slurry is pumped into the stratum, and the mixing head is slowly lifted at a speed of not more than 0.5 m / min to realize the first grouting and mixing, and ensure that the cement slurry and the undisturbed soil are fully mixed.

[0110] In step S96, after the mixing head is lifted to the pile top design elevation, it is again sunk to the pile bottom to perform secondary mixing treatment on the formed cement-soil pile, and the slurry can be supplemented as needed to further enhance the strength and uniformity of the pile bottom.

[0111] In step S97, the mixing head is lifted at a set speed for the second time to complete the second lifting and mixing process to ensure that the cement slurry is fully and uniformly distributed in the full length range of the mixing pile.

[0112] In step S98, it is judged whether the complete reciprocating operation cycle of at least one sinking and lifting and reciprocating has been completed, if not, it is returned to step S94 to continue the cycle until the design requirements are met.

[0113] When the reciprocating operation is completed, step S99 is entered, and for the area provided with the composite drainage node 11, slurry mixed with coarse aggregate or cement slurry with a lower cement content can be used for specific site construction at the corresponding intersection pile position according to design requirements to realize differential enhancement and drainage function.

[0114] Step S2 (system installation):

[0115] During the maintenance of the grid-shaped cement mixing wall 1, the installation of the partitioned vacuum preloading system 2 and the multi-dimensional real-time monitoring system 200 is carried out. In each control partition enclosed by the grid-shaped cement mixing wall 1, drainage boards 21 are vertically inserted at an interval of 1.0 to 1.5 meters. The pipe network composed of vacuum main pipes 22 and vacuum branch pipes 23 is laid, and intelligent pressure regulating valves 26 and bypass pulse valves 27 are installed. Then, a sealing film 24 is covered on the ground, and the edge thereof is connected with the top of the grid-shaped cement mixing wall 1 through sand bag compaction to form an airtight connection.

[0116] The layout of the multi-dimensional real-time monitoring system 200 is simultaneously carried out. According to the design drawings, settlement observation points 3 are buried in each partition, vacuum degree sensors 4 are installed at the vacuum pipeline nodes, lateral displacement meters 5 are installed outside the grid-shaped cement mixing wall 1, and wall stress sensors 7 are buried in the wall body close to the composite drainage node 11. All sensors are connected to the data acquisition unit through data lines, and the unit establishes communication with the central control module 100 through a wireless network.

[0117] Step S3 (differential vacuum degree dynamic regulation):

[0118] Referring to the accompanying drawings, Figure 6 After the system installation is completed, the vacuum pump group is started, and the central control module 100 begins to execute the closed-loop regulation based on the wall-soil collaborative deformation control model. The module continuously receives and analyzes the settlement data uploaded by each settlement observation point 3, with the minimum difference in the settlement rate of each partition as the control target.

[0119] For example, if the central control module 100 monitors that the settlement rate (curve VA) of partition A is significantly higher than the settlement rate (curve VB) of adjacent partition B, in order to prevent excessive uneven settlement, the central control module 100 automatically generates and sends instructions to the intelligent pressure regulating valve 26 installed on the pipeline of partition A to slightly reduce its opening degree, thereby reducing the vacuum degree (curve PA) of partition A and slowing down its settlement rate. At the same time or subsequently, the module can instruct the intelligent pressure regulating valve 26 of partition B to slightly increase its opening degree to increase the vacuum degree (curve PB) of partition B to accelerate its settlement. This process is continuously and dynamically executed until the settlement rates of each partition tend to be consistent.

[0120] Step S4 (continuous judgment of consolidation bottleneck state):

[0121] In the process of vacuum preloading, the central control module 100 performs a continuous judgment of the consolidation bottleneck state for each regulated partition. This judgment is a comprehensive analysis process. When the central control module 100 monitors that the settlement rate of a certain partition is below the preset threshold (for example, 1 mm / d) according to the formula , it does not immediately perform intervention, but starts a comprehensive analysis program.

[0122] This program will cross-verify other relevant monitoring data of the partition: check whether the reading of the vacuum degree sensor 4 of the partition is stably maintained at the target value (for example, ≥80 kPa); check whether the reading of the lateral displacement meter 5 is within the allowed range (for example, ≤50 mm); and check whether the data of the wall stress sensor 7 has a stress mutation caused by abnormal changes of soil pressure. Only when it is confirmed that the vacuum degree is normal and the wall state is stable, the module finally determines that the partition enters the consolidation bottleneck state caused by internal reasons of the soil body (for example, local drainage channel blockage), rather than caused by system equipment failure.

[0123] Step S5 (active pulse intervention and strong vacuum pumping):

[0124] Referring to Figure 7 , when the central control module 100 confirms that a certain partition (for example, the C partition in the figure) enters the consolidation bottleneck state (at T1), it immediately automatically performs active pulse intervention. The central control module 100 sends a short opening instruction to the bypass pulse valve 27 corresponding to the partition. The valve is temporarily opened, and high-pressure air is injected into the underground vacuum pipe network, so that the space under the sealing membrane is temporarily pressurized. This pressure is preferentially transmitted to the deep layer of the foundation through the fluid communication effect, and is efficiently conducted to the consolidated soil body through the low-resistance channel of the composite drainage node 11, to produce disturbance.

[0125] After the pulse ends, the valve is closed, and the central control module 100 immediately instructs the control of the vacuum pump of the partition to run at maximum power to perform a strong vacuum pumping operation on the partition. This operation takes advantage of the favorable opportunity that the pore structure of the soil body is dredged after the pulse disturbance, and quickly pumps out the loose pore water, so as to break the consolidation bottleneck and restore the settlement rate (after T2). This operation cycle of positive pressure pulse and strong vacuum pumping can be repeatedly performed according to the preset logic until the consolidation state of the partition returns to normal.

[0126] Step S6 (acceptance):

[0127] When the consolidation degree of all partitions reaches the design requirement (for example, ≥ 85%), stop vacuum preloading. After removing the relevant equipment, the effect of the completed foundation is accepted. The acceptance standards include: using the ring knife method to detect the compaction degree of the foundation, requiring the compaction degree in the 0-0.8m depth range of the main road area to be not less than 95%, and the compaction degree of other areas to be not less than 94%; using the bearing plate method to detect the rebound modulus, requiring the comprehensive rebound modulus of the foundation of the main road to be not less than 40MPa, and the comprehensive rebound modulus of other areas to be not less than 35MPa. If the acceptance is qualified, it proves that the method described in the embodiment of the application achieves the expected foundation reinforcement effect, and can be delivered for subsequent bucket-wheel machine foundation structure construction.

[0128] The above detailed embodiments are only one specific application example of the application, and the disclosed system and method are not limited to port engineering. It is also applicable to other engineering scenarios with similar soft soil foundation reinforcement requirements. Some other application embodiments of the application are listed as follows:

[0129] In railway and high-speed railway engineering, it can be applied to deal with deep and weak foundation. For example, when facing a silt layer with an average thickness of 25 meters, the system and method of the embodiment of the application can be applied to reinforce the foundation through the synergistic effect of vacuum preloading and grid-shaped cement mixing wall, so as to meet the engineering construction requirement that the post-construction settlement is controlled within 30 centimeters.

[0130] In the field of airport and highway engineering, especially in large-area soft soil foundation treatment projects of coastal airport runways or reclamation areas, the system and method of the embodiment of the application can be used. By implementing the application, the bearing capacity of the foundation can be improved from, for example, 50kPa before reinforcement to more than 150kPa, and the uneven settlement can be effectively controlled.

[0131] In foundation treatment engineering in earthquake-prone areas, the embodiment of the application can be used for liquefaction resistance reinforcement of sandy soil foundation. In such applications, the lateral restraint effect of the grid-shaped cement mixing wall combined with the drainage effect of the vacuum preloading system helps to reduce the accumulation of excess pore water pressure in the foundation soil under the action of seismic load, thereby improving the liquefaction resistance of the foundation.

[0132] It is also applicable to municipal and industrial facility construction with strict control requirements on post-construction settlement. For example, in the construction of urban rail transit engineering or large tank foundation, the foundation can be reinforced by using the embodiment of the application. In addition, in deep foundation pit engineering, the foundation around the foundation pit can be treated by using the application to reduce the impact of construction on adjacent buildings.

[0133] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A ground reinforcement system of a vacuum preloading combined with a grid-shaped cement mixing wall, characterized in that, The system comprises: A grid-shaped cement mixing wall is arranged in a foundation to be reinforced, and is formed by a plurality of cement mixing piles which are mutually overlapped to form a grid-shaped structure, wherein a composite drainage node is arranged at the intersection node of the grid-shaped cement mixing wall, and the permeability of the composite drainage node is higher than that of the remaining part of the grid-shaped cement mixing wall; A vacuum preloading system is divided into a plurality of sub-zones, and each sub-zone is provided with an intelligent pressure regulating valve; A multi-dimensional real-time monitoring system comprises a settlement observation point, a vacuum degree sensor, a lateral displacement meter and a wall stress sensor arranged in the sub-zone; A central control module is electrically connected with the multi-dimensional real-time monitoring system and the intelligent pressure regulating valve, and is prearranged with a wall-soil collaborative deformation control model; The central control module is used for receiving real-time monitoring data of the settlement observation point, the vacuum degree sensor, the lateral displacement meter and the wall stress sensor, inputting the real-time monitoring data into the wall-soil collaborative deformation control model for analysis and operation to generate a vacuum degree control instruction for each sub-zone, and sending the vacuum degree control instruction to the intelligent pressure regulating valve to dynamically adjust the vacuum degree of each sub-zone; The composite drainage node is integrally formed with the grid-shaped cement mixing wall in multiple ways: During the pile construction at the intersection node position of the grid-shaped cement mixing wall, predetermined particle size and proportion of coarse aggregate are mixed into the cement slurry to form a cement-soil aggregate composite body with an internal interconnected gap network; During the pile construction at the intersection node position of the grid-shaped cement mixing wall, the cement content in the cement slurry is reduced to form a cement-soil body with a higher permeability coefficient than the standard wall part of the grid-shaped cement mixing wall; The vacuum preloading system is further provided with a bypass pulse valve in each sub-zone, the bypass pulse valve is arranged on a bypass pipeline connected in parallel with a vacuum main pipeline corresponding to the sub-zone, the bypass pipeline is connected with an independent pressure source, the bypass pulse valve is electrically connected with the central control module, and is used for applying a positive pressure pulse to the corresponding sub-zone according to a pulse instruction sent by the central control module; The specific condition for the central control module to execute the positive pressure pulse is: When the central control module determines that the consolidation state of any sub-zone enters a consolidation bottleneck state based on the real-time monitoring data collected by the settlement observation point; The judgment condition of the consolidation bottleneck state is that the settlement rate of the sub-zone satisfies the following formula: ； In the formula, a settlement amount measured at a settlement observation point; is time; is a preset settlement rate threshold value; When the wall-soil collaborative deformation control model generates the vacuum degree control instruction, the analysis and operation target is to minimize the settlement rate difference between any two sub-zones, and the objective function of the settlement rate difference is: ； In the formula, is the settlement rate of the area calculated by the central control module according to the real-time monitoring data of the settlement observation point is the settlement rate of the area calculated by the central control module according to the real-time monitoring data of the settlement observation point is the settlement rate of the area calculated by the central control module according to the real-time monitoring data of the settlement observation point is the settlement rate of the area calculated by the central control module according to the real-time monitoring data of the settlement observation point 2. The vacuum preloading combined geogrid-like cement mixed wall foundation reinforcing system according to claim 1, characterized in that, The wall stress sensor in the multi-dimensional real-time monitoring system is a vibrating wire stress meter, the wall stress sensor is buried near the composite drainage node, the wall stress sensor is used for monitoring stress response data of the composite drainage node when the vacuum degree is dynamically adjusted or the positive pressure pulse is applied by the vacuum preloading system, and the stress response data is sent to the central control module as part of the real-time monitoring data.

3. A method for ground improvement by vacuum preloading combined with a grid-shaped cement-mixed wall, which is applied to the ground improvement system by vacuum preloading combined with a grid-shaped cement-mixed wall according to claim 1 or 2, characterized in that, The method comprises the following steps: S1, a grid-shaped cement mixing wall is constructed through the soft soil layer, and a composite drainage node with higher permeability than the remaining part of the grid-shaped cement mixing wall is formed at the intersection node of the grid-shaped cement mixing wall; S2, a partitioned vacuum preloading system and a multi-dimensional real-time monitoring system are installed; S3, real-time monitoring data is collected by the multi-dimensional real-time monitoring system, and the real-time monitoring data is analyzed and operated by a central control module based on a wall-soil cooperative deformation control model to generate vacuum degree control instructions for each partition and to dynamically control the vacuum degree of each partition in a differentiated manner; S4, during the differential vacuum degree dynamic control process, the central control module continuously determines whether there is a partition entering the consolidation bottleneck state; S5, when it is determined that any partition enters the consolidation bottleneck state, the central control module instructs the bypass pulse valve corresponding to the partition to open to apply a positive pressure pulse, and after the bypass pulse valve is closed, instructs the vacuum pump of the control partition to pump at a power higher than the normal operating power.

4. The method for ground reinforcement according to Claim 3, wherein In step S1, the step of constructing the grid-shaped cement mixing wall through the soft soil layer includes: During the process of using a deep mixer for spouting and mixing, at least one reciprocating operation of sinking and re-mixing and lifting and re-mixing is performed to improve the mixing uniformity of the cement slurry and the foundation soil.

5. The method for ground improvement according to claim 3, wherein When the central control module dynamically controls the vacuum degree of each partition in a differentiated manner based on the wall-soil cooperative deformation control model, the control target for generating the vacuum degree control instructions is to minimize the difference in settlement rate between any two partitions.

6. The method for ground reinforcement with a vacuum preloading combined with a lattice cement mixed wall according to claim 3, wherein In step S4, during the differential vacuum degree dynamic control process, the step of continuously determining by the central control module whether there is a partition entering the consolidation bottleneck state includes: The central control module comprehensively analyzes the settlement data, vacuum degree data, lateral displacement data and wall stress data collected by the multi-dimensional real-time monitoring system to determine whether there is a partition entering the consolidation bottleneck state.

Images