Three-phase load combined pre-pressing construction method and system based on intersection surface elevation control

Abstract

The invention provides a three-phase load combined pre-pressing construction method and system based on intersection surface elevation control, and relates to the technical field of foundation treatment. According to the method, a horizontal drainage layer is formed above a target site, a drainage plate is inserted into the target site, a foundation of the target site is a soft soil foundation, and the top of the drainage plate is buried in the horizontal drainage layer; a vacuumizing layer is formed on the side, away from the target site, of the horizontal drainage layer, and vacuumizing is conducted through the vacuumizing layer; determining that vacuumizing is completed, and constructing above a vacuumizing layer to form a pile loading layer and a water loading layer; and determining that unloading conditions are met, removing the water load layer, carrying out vibration compaction construction on the stacking layer, and cleaning the target site. Three-phase load combined pre-pressing construction of the target site can be achieved through the negative pressure load of the vacuum layer, the soil load of the surcharge loading layer and the liquid phase load of the water load layer, the water content of the target site is reduced, the strength and bearing capacity of the target site are effectively improved, the construction cost is low, the reinforcement construction period is short, and the construction period is shortened. And the construction time and cost are greatly saved.

Description

Technical Field

[0001] The present application relates to the technical field of foundation treatment, and in particular to a three-phase load combined preloading construction method and system based on handover surface elevation control. Background Art

[0002] Most of the soil layers in my country's coastal areas are soft soil layers deposited in modern times. This type of soil has the characteristics of high water content, high compressibility, poor permeability, low strength and bearing capacity, large layer thickness and uneven distribution. People usually call it soft clay. With the rapid development of economic construction, construction, transportation, energy and other projects in coastal areas have also developed rapidly. However, due to limited conditions, many projects need to be built on offshore soft foundations or ultra-soft sea silt filling land foundations. This kind of offshore ultra-soft sea soil has high water content and very low strength and bearing capacity. Building buildings on this soft foundation will cause foundation shear failure, settlement and excessive settlement difference, affecting the safety and normal use of the building. Therefore, it is necessary to reinforce this soft soil foundation. Summary of the invention

[0003] The embodiment of the present application provides a three-phase load combined preloading construction method and system based on handover surface elevation control, which can solve the problems of high water content, low strength and bearing capacity of existing soft soil foundations.

[0004] In order to achieve this purpose, the embodiments of the present application provide the following solutions.

[0005] According to one aspect of the embodiment of the present application, a three-phase load combined preloading construction method based on handover surface elevation control is provided, comprising forming a horizontal drainage layer above a target site, inserting a drainage board into the target site, wherein the foundation of the target site is a soft soil foundation, and the top of the drainage board is buried in the horizontal drainage layer;

[0006] forming a vacuum layer on a side of the horizontal drainage layer away from the target site, and using the vacuum layer to perform vacuuming;

[0007] Determine that vacuuming is completed, construct a loading layer and a water loading layer above the vacuuming layer, the water loading layer is located above the loading layer, and the heights of the loading layer and the water loading layer correspond to the elevation of the handover surface of the target site;

[0008] Determine that the unloading conditions are met, remove the water load layer, construct the stack load layer by vibration, and clean up the target site. The unloading conditions include at least one of standing for a preset time and a daily settlement rate less than a preset settlement value.

[0009] In a possible implementation, the horizontal drainage layer includes a first drainage layer and a second drainage layer, and forming the horizontal drainage layer above the target site includes:

[0010] Cleaning the target site, and laying preset materials on the target site, wherein the preset materials include geotextiles;

[0011] Laying medium-coarse sand with a first thickness on the preset material to form a sand cushion layer, and determining the sand cushion layer as the first drainage layer;

[0012] The step of inserting the drainage board into the target site comprises:

[0013] Inserting the drainage board into the target site by using a board inserting machine, so that the top of the drainage board exposes the first drainage layer;

[0014] It is determined that the insertion of the drain board is completed, and medium-coarse sand is laid according to the exposed height of the drain board to form the second drainage layer, and the top of the drain board is buried in the second drainage layer.

[0015] In a possible implementation, a vacuum main pipe and a filter pipe are laid above the medium-coarse sand buried in the drainage board, and a vacuum extraction system is arranged outside the target site;

[0016] The preset material and the sealing film are laid in sequence on the vacuum main pipe and the filter tube, and the sealing film is pressed into the film pressing groove.

[0017] In a possible implementation, forming the loading layer includes:

[0018] Laying a first preset number of layers of the preset material on the vacuum layer;

[0019] The thickness of the loading layer is obtained, and soil is filled according to the thickness and preset settlement conditions to form the loading layer. The preset settlement conditions include a surface settlement rate that is less than or equal to a first preset value per day and night.

[0020] In a possible implementation, the formation of the water-bearing layer includes:

[0021] The water load layer is formed on the first waterproof material according to a second preset height, the water load is arranged in at least one of a water bag, a water tank, and a water cofferdam, and the first waterproof material includes an impermeable geomembrane.

[0022] In a possible implementation, forming the water-bearing layer on the first waterproof material according to the second preset height includes:

[0023] The water load height of the water load layer is obtained, a target water load is determined according to the water load height and the second preset height, and the water load layer is formed by using the first waterproof material and the target water load.

[0024] In a possible implementation, the target water load is a water cofferdam, and forming the water load layer by using the first waterproof material and the target water load includes:

[0025] A cofferdam having a third preset height is built around the target site, wherein the cross-sectional shape of the cofferdam corresponds to the height and bulk density of the water load layer, and the third preset height is greater than the water load height;

[0026] A third preset number of layers of second waterproof material are laid and fixed in the cofferdam, and water is injected into the water-containing space formed by the second waterproof material to form the water-loading layer.

[0027] In a possible implementation, the heights of the stacking layer and the water loading layer satisfy formula (1):

[0028] p=γ s ·h 1 +γ w h 2 (1), where p represents the upper load, γ w represents the bulk density of water in the water-loading layer, γ s Indicates the bulk density of the pile material in the pile layer, h 1 is the height of the loading layer, h 2 is the height of the water loading layer.

[0029] In a possible implementation, the heights of the pile loading layer and the water loading layer are calculated by formulas (1), (2), and (3), wherein formulas (2) and (3) are respectively:

[0030] h 1 =H-h+s+s 1 (2)

[0031] s 1 =m v γ w h 2 ·h 1 (3)

[0032] In the formula, H represents the elevation of the delivery surface, h represents the elevation of the target site, s represents the settlement of the target site during construction, and s 1 is the additional consolidation of the loading layer, m v is the additional consolidation coefficient.

[0033] In a possible implementation, the vibrating and tamping the loading layer includes:

[0034] Vibration tamping construction is performed on the loading layer, and the vibration tamping construction includes spot tamping and full tamping. The tamping point of the vibration tamping construction is determined according to the position of the drainage board.

[0035] According to one aspect of an embodiment of the present application, a three-phase load combined preloading construction system based on handover surface elevation control is provided, the system includes construction equipment, the construction equipment includes a drainage board, and the system implements the three-phase load combined preloading construction method based on handover surface elevation control as described above through the construction equipment.

[0036] In a possible implementation, the construction equipment includes a sensor and a computer processing terminal, and the sensor includes a pore water pressure gauge, a displacement sensor, and a vacuum pressure gauge;

[0037] The pore water pressure gauge is buried in the soil layer of the target site, the vacuum pressure gauge is buried in the horizontal drainage layer, and the displacement sensor is buried at the bottom of the heap layer and the top of the heap layer;

[0038] The computing and processing terminal is connected to the sensor. After determining that the vacuum is drawn, the computing and processing terminal obtains the data collected by the sensor and draws a sedimentation time course curve according to the data.

[0039] In a possible implementation, the displacement sensor includes a first displacement sensor and a second displacement sensor. The first displacement sensor is buried at the bottom of the loading layer, and the second displacement sensor is buried at the top of the loading layer. After the construction of the loading layer is completed, the second displacement sensor starts working and uploads data to the computer processing terminal.

[0040] In a possible implementation, the embedding of the sensor includes:

[0041] After the drainage board is installed, bury the pore water pressure gauge;

[0042] After the horizontal drainage layer is laid, bury the vacuum pressure gauge;

[0043] A first displacement sensor is buried above the vacuum layer, and a second displacement sensor is buried after the construction of the loading layer is completed.

[0044] In a possible implementation, the construction equipment further includes a water pump and a water storage container for storing water, and the water pump is used to inject water from the water storage container into the water load or inject water from the water load into the water storage container;

[0045] The water pump is used to inject water into or pump water out of the water load;

[0046] When the water load layer is formed, the working time of the water pump is determined by formula (4);

[0047]

[0048] In the formula, t is the working time, n is the number of water loads, S is the bottom area of ​​the water load; h 2 is the height of the water load layer, and v represents the pumping speed of the water pump.

[0049] Optionally, the forming of the water load comprises:

[0050] Using water load to form a water load layer, obtaining a current consolidation degree calculation curve corresponding to the current settlement time history curve, and generating an error between the current consolidation degree calculation curve and a preset consolidation degree calculation curve;

[0051] The water pump is controlled to inject water into or pump water out of the water load according to the error.

[0052] The beneficial effects of the technical solution provided by the embodiment of the present application are:

[0053] The three-phase load combined preloading construction method and system based on the control of the handover surface elevation provided by the present application forms a horizontal drainage layer above the target site, inserts the drainage board into the target site, the foundation of the target site is a soft soil foundation, and the top of the drainage board is buried in the horizontal drainage layer; a vacuum layer is formed on the side of the horizontal drainage layer away from the target site, and the vacuum layer is used for vacuuming; after the vacuuming is completed, a loading layer and a water loading layer are constructed above the vacuum layer; after the unloading conditions are determined to be met, the water loading layer is removed, and the loading layer is vibrated to clean the target site. The embodiment of the present application sets a vacuum layer and a water loading layer on the target site, and after removing the water loading layer, the loading layer is vibrated to construct, which can realize the three-phase load combined preloading construction of the target site through the negative pressure load (gas phase load) of the vacuum layer, the soil load (solid phase load) of the loading layer, and the liquid phase load of the water loading layer, effectively reducing the water content of the target site, improving the strength and bearing capacity of the target site, and the construction cost is low, the reinforcement period is short, and the construction time and cost are greatly saved. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following is a brief introduction to the drawings required for use in describing the embodiments of the present application.

[0055] Figure 1 A flowchart of a three-phase load combined preloading construction method based on handover surface elevation control provided in an embodiment of the present application;

[0056] Figure 2 A schematic diagram of soft soil foundation reinforcement provided in an embodiment of the present application;

[0057] Figure 3 A schematic diagram of the distribution of strong compaction points provided in an embodiment of the present application;

[0058] Figure 4 A schematic diagram of the distribution of vibration and tamping points provided in an embodiment of the present application;

[0059] Figure 5 A schematic diagram of the arrangement of a computer processing terminal and a water pump provided in an embodiment of the present application.

[0060] Explanation of numbers: 1. Target site; 2. Drainage board; 3. Vacuum system; 4. Water load; 5. Film pressing ditch; 6. Filter tube; 7. Loading layer; 8. Strong compaction point; 9. Vibration compaction point; 10. Water pump; 11. Computer processing terminal; 12. Water storage container; 13. Pipeline. DETAILED DESCRIPTION

[0061] The embodiments of the present application are described below in conjunction with the drawings in the present application. It should be understood that the implementation methods described below in conjunction with the drawings are exemplary descriptions for explaining the technical solutions of the embodiments of the present application and do not constitute a limitation on the technical solutions of the embodiments of the present application.

[0062] It will be understood by those skilled in the art that, unless specifically stated, the singular forms "one", "said", and "the" used herein may also include plural forms. It should be further understood that the terms "including" and "comprising" used in the embodiments of the present application refer to that the corresponding features can be implemented as the presented features, information, data, steps, operations, elements and / or components, but do not exclude the implementation of other features, information, data, steps, operations, elements, components and / or combinations thereof supported by the present technical field. It should be understood that when we say that an element is "connected" or "coupled" to another element, the one element may be directly connected or coupled to the other element, or it may refer to that the one element and the other element establish a connection relationship through an intermediate element. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The term "and / or" used herein indicates at least one of the items defined by the term, for example, "A and / or B" indicates that it is implemented as "A", or is implemented as "A", or is implemented as "A and B".

[0063] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0064] The following describes several exemplary embodiments to illustrate the technical solutions of the embodiments of the present invention and the technical effects produced by the technical solutions of the present invention. It should be noted that the following embodiments can refer to, draw on or combine with each other, and the same terms, similar features and similar implementation steps in different embodiments will not be described repeatedly.

[0065] The three-phase load combined preloading construction method and system based on handover surface elevation control provided in the present application is intended to solve at least one technical problem existing in the prior art.

[0066] The present application provides a three-phase load combined preloading construction method based on the control of the delivery surface elevation. Figure 1-Figure 4 As shown, the method includes:

[0067] S101: forming a horizontal drainage layer above the target site 1 and inserting the drainage board 2 into the target site 1.

[0068] Optionally, the foundation of the target site 1 is a soft soil foundation, and the soil in the soft soil foundation is soft soil, which refers to fine-grained soil with high natural water content, large porosity, high compressibility, and low shear strength deposited in coastal areas, lakes, valleys, and river beaches. It has the characteristics of high natural water content, large natural porosity, high compressibility, low shear strength, small consolidation coefficient, long consolidation time, high sensitivity, high disturbance, poor permeability, complex layered distribution of soil layers, and large differences in physical and mechanical properties between layers.

[0069] Optionally, the horizontal drainage layer includes a first drainage layer and a second drainage layer, and a horizontal drainage layer is formed above the target site 1, including: cleaning the target site 1, laying a preset material on the target site 1, the preset material including a geotextile; laying medium-coarse sand with a first thickness on the preset material to form a sand cushion layer, and determining the sand cushion layer as the first drainage layer. Inserting the drain board 2 into the target site 1 includes: using a board inserting machine to insert the drain board 2 into the target site 1, and the top of the drain board 2 is exposed from the first drainage layer; determining that the insertion of the drain board 2 is complete, laying medium-coarse sand according to the exposed height of the drain board 2 to form a second drainage layer, and the top of the drain board 2 is buried in the second drainage layer.

[0070] In one embodiment, the target site 1 is cleaned to prepare for the next construction step. The cleaning of the target site 1 includes: removing sharp objects such as plant roots and stones in the target site 1 to prevent the objects from piercing the sealing film of the vacuum layer and affecting the reinforcement effect. The site is filled and leveled to ensure that there is no obvious bulge in the site (such as the bulge height is greater than the predetermined height), and the elevation of the target site 1 is measured.

[0071] Optionally, the preset material may be a water-permeable geosynthetics made of synthetic fibers by needle punching or weaving, specifically, may be a woven geotextile or a non-woven filament geotextile.

[0072] Optionally, the laying thickness of the medium-coarse sand can be determined according to the construction specifications corresponding to the target site 1, and the laying thickness can be 0.3-0.5 meters.

[0073] In one embodiment, after the target site 1 is cleaned, a geotextile is laid in the target site 1. Medium-coarse sand with a thickness of h is pushed on the geotextile and leveled to form a first drainage layer, wherein the value range of h is 0.3 to 0.5 meters.

[0074] Optionally, the number and density of the drain boards 2 can be determined according to the construction specifications related to the drain boards 2. Specifically, the drain boards 2 can be inserted into the target site 1 at intervals of 1m, and the pattern formed by the inserted drain boards 2 can be a triangle or a square.

[0075] Optionally, the depth to which the drainage board 2 is inserted into the soft soil layer in the target site 1 can be determined according to the depth of the soft soil layer and the use requirements of the target site 1 (such as the bearing requirements and strength requirements of the reinforced target site 1).

[0076] Optionally, a board inserting machine may be used to insert the drainage board 2 into the target site 1, wherein the board inserting machine may include one or more of a walking board inserting machine, a crawler board inserting machine and a track board inserting machine.

[0077] Optionally, the first drainage layer may be exposed from the top of the drainage board 2. Specifically, the first drainage layer may be exposed by 1 cm from the top of the drainage board 2.

[0078] Optionally, l can be 30, or 20, 25 or other values. The specific value can be determined according to the construction environment, the type of drainage board 2, the type of board inserting machine and other conditions.

[0079] Optionally, after the drainage board 2 is inserted, the portion of the drainage board 2 exposed from the first drainage layer is buried in the medium-coarse sand by laying medium-coarse sand again to form a second drainage layer, so as to facilitate the subsequent laying of the vacuum main pipe and the filter pipe 6.

[0080] S102: forming a vacuum layer on the side of the horizontal drainage layer away from the target site 1, and using the vacuum layer to perform vacuuming.

[0081] Optionally, a vacuum layer is formed on the side of the horizontal drainage layer away from the target site 1, including: laying a vacuum main pipe and a filter pipe 6 above the medium-coarse sand buried in the drainage board 2, and setting a vacuum system outside the target site 1; laying preset materials and a sealing film in sequence above the vacuum main pipe and the filter pipe 6, and pressing the sealing film into the film pressing groove 5.

[0082] Optionally, the vacuum main pipe and the filter pipe 6 are laid separately on the medium-coarse sand, and the vacuum main pipe and the filter pipe 6 can be laid on the medium-coarse sand in a fishbone structure. The filter pipe 6 can be laid horizontally.

[0083] In one embodiment, the preset material may be a geotextile. After the vacuum main pipe and the filter tube 6 are laid, the geotextile is first laid on the vacuum main pipe and the filter tube 6, and then the sealing film is laid. A film pressing groove 5 may be provided on the side of the target site 1, and the sealing film is pressed into the film pressing groove 5. After the sealing film is laid, the vacuum system 3 on one side of the target site 1 may be connected to the vacuum main pipe and the filter tube 6, and the vacuum system 3 may be used to perform a vacuum operation.

[0084] S103: After the vacuuming is completed, a loading layer 7 and a water loading layer are constructed above the vacuuming layer.

[0085] Optionally, the water load layer is located above the loading layer 7. The formation of the loading layer 7 includes: laying a first preset number of layers of preset materials above the vacuum layer; obtaining the thickness of the loading layer 7, filling soil materials according to the thickness and preset settlement conditions to form the loading layer 7, and the preset settlement conditions include that the surface settlement rate is less than or equal to a first preset value per day and night. The first preset value can be 15 mm or other values, and the specific size of the value can be determined according to the foundation parameters of the target site 1, construction requirements (limited construction time) and other conditions.

[0086] Optionally, the preset number of layers may be two layers or another number of layers, and the preset material may be a geotextile. The number of layers of the preset material may be determined according to construction requirements and the type of the preset material.

[0087] Optionally, soil material may be piled on the sealing membrane in a graded construction manner to form a pile layer 7. The number of construction stages of the graded construction may be determined according to the thickness of the pile layer 7.

[0088] Optionally, the thickness of each level of the filling in the graded construction does not exceed 2 meters. The filling soil material can be sandy soil or fine sand.

[0089] In one embodiment, the thickness of the backfill layer 7 is 3 meters, and the backfill is carried out in a three-level construction manner, with a backfill thickness of 1 meter each time. In addition, during the backfill process, the surface settlement rate of the target site 1 is ensured to be no greater than 15 mm per day and night.

[0090] Optionally, the formation of the water load layer includes: forming a water load layer located on the first waterproof material according to a second preset height, the arrangement of the water load 4 includes at least one of a water bag, a water tank, and a water cofferdam, and the first waterproof material includes an impermeable geomembrane, an impermeable geotextile and other geosynthetics that can prevent water infiltration.

[0091] Optionally, when the first waterproof material is an impermeable geomembrane, before laying the impermeable geomembrane, a layer of geotextile may be laid on the loading layer 7, and then the impermeable geomembrane may be laid. The number of the impermeable geomembrane may be one or two layers.

[0092] Optionally, a water load layer is formed on the first waterproof material according to a second preset height, including: obtaining the water load height of the water load layer, determining a target water load 4 according to the difference between the water load height and the second preset height, and forming the water load layer using the first waterproof material and the target water load 4.

[0093] Optionally, when the water load height is higher than the second preset height, a water tank or a water cofferdam can be used as the water load 4, and when the water load height is not higher than the second preset height, a water bag can be used as the water load 4.

[0094] Optionally, the second preset height may be 2 meters, or 1.5 meters, 3 meters, or other values. The water used by the water load 4 may include seawater, fresh water, or other types of water. The type of water may be determined based on the difficulty and method of obtaining it. Specifically, water may be directly obtained from lakes, rivers, and oceans around the target site 1, and the water may be injected into the water load 4 to increase the speed of forming the water load layer and reduce the construction cost.

[0095] Optionally, when the target site 1 is a water cofferdam, the water load layer is formed by using the first waterproof material and the target water load 4, including: building a cofferdam with a height of a third preset height around the target site 1, the cross-sectional shape of the cofferdam corresponds to the height and bulk density of the water load layer, and the third preset height is greater than the water load height; laying and fixing the third preset number of layers of the second waterproof material in the cofferdam, and injecting water into the water-containing space formed by the second waterproof material to form a water load layer. The first waterproof material is overlapped and fixed on all sides with the cofferdam.

[0096] Optionally, the third preset height can be set to be one meter higher than the water load height according to construction requirements. Specifically, the water load height is h 2 , the height of the cofferdam can be h 2 +1 meter.

[0097] Optionally, the shape of the cofferdam cross section may be calculated based on the product of the bulk density of the water load 4 and the height of the water load to ensure that the cofferdam can withstand the triangular lateral load of the water load 4 .

[0098] In one embodiment, the second preset height is two meters, and it is determined that the water load height is greater than 2 meters, and a water cofferdam is used to reinforce the target site 1. 2 +1m cofferdam, stability check is carried out for the cofferdam cross-section to ensure that w h 2 The triangular lateral load of can maintain sufficient stability performance, where γ w Indicates the bulk density of water in water load 4, h 2 is the height of the water load layer. Two layers of anti-seepage geotextiles are laid inside the cofferdam. The anti-seepage geotextiles are overlapped and fixed around the cofferdam. A water solution with a height of h is injected above the geotextiles. 2 of water, thereby applying a water load 4 to the target site 1 using a water loading layer.

[0099] Optionally, the heights of the pile loading layer 7 and the water loading layer satisfy formula (1):

[0100] p=γs ·h 1 +γ w h 2 (1), where p represents the upper load, γ w represents the bulk density of water in the water-loading layer, γ s Indicates the bulk density of the pile material in the pile layer 7, h 1 is the height of the loading layer 7, h 2 is the height of the water load layer. The weight of the upper load can be determined according to the use requirements of the target site 1.

[0101] Optionally, the heights of the pile loading layer 7 and the water loading layer correspond to the elevation of the handover surface of the target site, and the heights of the pile loading layer 7 and the water loading layer can be calculated by formulas (1), (2), and (3), wherein formulas (2) and (3) are respectively:

[0102] h 1 =H-h+s+s 1 (2)

[0103] s 1 =m v γ w h 2 ·h 1 (3)

[0104] Where H represents the elevation of the handover surface (the height of the top surface after the construction of the target site 1 is completed), h is the elevation of the target site 1, s is the settlement of the target site 1 during the construction period, and s 1 is the additional consolidation of the loading layer 7, m v is the additional consolidation coefficient. The height of the loading layer 7 and the height of the water load layer can be quickly obtained by formulas (1), (2) and (3). The water load 4 has the advantages of simple source, easy unloading and no need for transportation in the later stage. The soil load formed by earth filling has the advantages of high density and can be directly used as a working cushion layer in the future, but it needs to be transported in the later stage. By organically combining the height of the water load and the height of the loading layer 7, the ratio of the water load 4 and the soil load can be coordinated, and the respective advantages of the water load 4 and the soil load can be brought into play. While meeting the upper load requirements (Formula 1), the height of the loading layer 7 after settlement can be basically flush with the handover surface (Formulas 2 and 3), thereby avoiding material transportation and achieving the purpose of saving construction time.

[0105] S104: Determine that the unloading conditions are met, remove the water load layer, perform vibration compaction on the load layer 7, and clean up the target site 1.

[0106] Optionally, the unloading condition includes at least one of a preset standing time and a daily sedimentation rate being less than a preset sedimentation value.

[0107] Optionally, the preset settlement value may be 1 cm, or 0.8 cm, 1.3 cm, or other values. The length of the preset time may also be determined according to construction requirements, characteristics of the target site 1 (such as moisture content, soil quality, etc.), and other conditions.

[0108] In one embodiment, after the construction of the water load layer is completed, after static loading for 60 days or waiting for the daily settlement rate to be less than 1 cm, the water load 4 on the loading layer 7 is unloaded, the site is cleaned, and the anti-seepage geomembrane and geotextile on the loading layer 7 are removed.

[0109] Optionally, the vibratory tamping construction of the backfill layer 7 includes: performing vibratory tamping construction on the backfill layer 7, the vibratory tamping construction includes spot tamping and full tamping, and the tamping point of the vibratory tamping construction is determined according to the position of the drainage board 2. Wherein, high-energy level vibratory tamping is performed on the backfill layer 7, and the vibratory tamping parameters can be determined according to the "Technical Regulations for Strong Compaction Foundation Treatment".

[0110] Optionally, the load layer 7 may be first vibrated and compacted in the form of full compaction, and then high-energy level compaction may be performed after two full compactions, wherein the high-energy level compaction includes spot compaction and full compaction, with spot compaction first and then full compaction.

[0111] Alternatively, if Figure 2 , Figure 3 As shown, during the vibration construction, the vibration point 9 is consistent with the position of the drain board 2. During the strong compaction, the strong compaction point 8 is staggered with the position of the drain board 2 to avoid the strong compaction point 8 and the position of the drain board 2 overlapping. Among them, the purpose of using vibration is to make the soil particles or soil aggregates around the drain board 2 move relative to each other, and the soil particles will be in a suspended state, achieving the effect of local liquefaction and alleviating the clogging of the drain board 2. The purpose of strong compaction is to transmit the impact force to the deep soft soil through the water column around the drain board 2, causing the deep soft soil excess pore water pressure, increasing the permeability potential gradient, and improving the soil drainage boundary conditions.

[0112] Optionally, after the vibration and tamping construction is completed, the surface layer of the heap layer 7 is filled to complete the reinforcement of the target site 1. The surface layer of the heap layer 7 can be filled and leveled with sandy soil.

[0113] The three-phase load combined preloading construction method based on the handover surface elevation control of the embodiment of the present application can realize the three-phase load combined preloading construction of the target site through the negative pressure load (gas phase load) of the vacuum layer, the soil load (solid phase load) of the load layer and the liquid phase load of the water load layer, effectively reducing the water content of the target site, having the advantages of reliable technology, lower cost and shorter reinforcement period, avoiding the problems of secondary transportation of piled materials on site, limited site yard and secondary treatment of foundation, saving time and cost, being applicable to coasts, lake sludge foundations and intertidal zones, and having high engineering application value and environmental ecological benefits.

[0114] Based on the same inventive concept, the present application also proposes a three-phase load combined preloading construction system based on the control of the delivery surface elevation, such as Figure 2-Figure 5 As shown, the system includes construction equipment, and the system implements the three-phase load combined preloading construction method based on handover surface elevation control as described in the above embodiment through the construction equipment.

[0115] Optionally, the construction equipment may include drainage boards 2, board inserting machines and other equipment related to the formation and construction of horizontal drainage layers, vacuum layers, loading layers 7 and water loading layers.

[0116] Alternatively, if Figure 5 As shown, the construction equipment includes sensors and a computer processing terminal 11. The sensors include a pore water pressure gauge, a displacement sensor and a vacuum pressure gauge. The pore water pressure gauge is buried in the soil layer of the target site 1, the vacuum pressure gauge is buried in the horizontal drainage layer, and the displacement sensor is buried at the bottom and top of the heap layer 7. The computing terminal is connected to the sensor. After determining the vacuum, the computer processing terminal 11 obtains the data collected by the sensor and draws a settlement time history curve based on the data. The settlement time history curve can be used to calculate the consolidation degree curve.

[0117] Optionally, the sensor can have the function of high-precision data collection and wireless transmission, the computer processing terminal 11 can be wirelessly connected to the sensor, and the computer processing terminal 11 can also be connected to various construction equipment with data processing functions used in the construction, to obtain the data of these construction equipment and control the operation of the construction equipment accordingly.

[0118] Optionally, the displacement sensor includes a first displacement sensor and a second displacement sensor. The first displacement sensor is buried at the bottom of the loading layer 7, and the second displacement sensor is buried at the top of the loading layer 7. After the construction of the loading layer 7 is completed, the second displacement sensor starts working and uploads data to the computer processing terminal 11.

[0119] Optionally, after the target site 1 starts to be vacuumed, the pore water pressure, vacuum pressure gauge and first displacement sensor may start working after the vacuuming operation is performed, and transmit the collected data to the computer processing terminal 11 .

[0120] Optionally, the embedding of the sensor includes: embedding a pore water pressure gauge after the drainage board 2 is inserted in the target site 1; embedding a vacuum pressure gauge after the horizontal drainage layer is laid; embedding a first displacement sensor above the vacuum layer, and embedding a second displacement sensor after the loading layer 7 is constructed. The sensor embedding work can be performed according to the "Construction Specifications for Water Transport Engineering Foundation".

[0121] Optionally, after the sealing film above the vacuuming layer is laid, a first displacement sensor may be buried above the sealing film. The first displacement sensor may collect data when vacuuming begins, and transmit the collected data to the computer processing terminal 11 .

[0122] Optionally, the construction equipment further includes a water pump 10 and a water storage container 12 for storing water; the water pump 10 is used to inject water from the water storage container 12 into the water load 4 or inject water from the water load 4 into the water storage container 12; when the water load layer is formed, the working time of the water pump 10 is determined by formula (4);

[0123]

[0124] Where, t is the working time, n is the number of water loads 4, S is the bottom area of ​​the water load 4; h 2 is the height of the water load layer, and v represents the pumping speed of the water pump 10. The water pump 10 can be connected to the water load 4 and the water storage container 12 through a pipeline 13. The water load 4 can be a water bag, a water tank, a water cofferdam, or other objects that can store water.

[0125] Optionally, the water storage container 12 may also be a water tower, a water tank, a water cofferdam, or an artificial or natural pond, river, lake, sea, etc. The computing terminal is connected to the water pump 10 to control the operation of the water pump 10 .

[0126] Optionally, the formation of the water load 4 includes: forming a water load layer using the water load 4, obtaining a current consolidation degree calculation curve corresponding to the current settlement time history curve, generating a comparison result between the current consolidation degree calculation curve and a preset consolidation degree calculation curve; and controlling the water pump 10 to inject or pump water into or out of the water load 4 according to the comparison result. The comparison result includes the value of the current consolidation degree calculation curve and the preset consolidation degree calculation curve and the error between the two.

[0127] Optionally, the preset consolidation degree calculation curve can be obtained from the preloading construction related design documents of the target site 1. The error can be 5% or other values.

[0128] In one embodiment, after the water load layer is formed, the consolidation calculation curve in the design file is compared with the measured consolidation calculation curve. When the measured consolidation calculation curve is lower than the consolidation calculation curve in the design file, and the error is greater than 5%, the pump 10 is turned on to add the water extracted from the water storage container 12 to the water load 4 of the water load layer until the height of the water load layer is raised by 0.2 meters (or 0.3 meters or other values). If the curve error is detected to be reduced within a preset time (which can be one day or 36 hours), the current load is maintained and the foundation is reinforced. If the curve error is not detected to be reduced within the preset time, water is repeatedly injected into the water load 4 to raise the height of the water load layer until the curve error is detected to be reduced within the preset time.

[0129] When the measured consolidation calculation curve is higher than the consolidation calculation curve in the design file, and the error is greater than 5%, the pump 10 is turned on to extract water from the water load layer through the pump 10, and the extracted water is injected into the water storage container 12 until the height of the water load layer is reduced by 0.2 meters. If the curve error is detected to be reduced within the preset time, the load is maintained to reinforce the foundation. If the curve error is not detected to be reduced within the preset time, the step of reducing the height of the water load layer is repeated until the error is detected to be reduced within the preset time. The automatic filling of the water load layer can be achieved by adjusting according to the consolidation calculation curve, and the water load layer height parameters in the reinforcement process can be adjusted in real time to ensure the reinforcement quality of the soft soil foundation.

[0130] The terms "first", "second", "third", "fourth", "1", "2", etc. (if any) in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that shown or described in the drawings.

[0131] It should be understood that, although each operation step is indicated by arrows in the flowchart of the embodiment of the present application, the implementation order of these steps is not limited to the order indicated by the arrows. Unless clearly stated herein, in some implementation scenarios of the embodiment of the present application, the implementation steps in each flowchart can be performed in other orders according to demand. In addition, some or all of the steps in each flowchart may include multiple sub-steps or multiple stages based on actual implementation scenarios. Some or all of these sub-steps or stages may be executed at the same time, and each sub-step or stage in these sub-steps or stages may also be executed at different times respectively. In different scenarios of execution time, the execution order of these sub-steps or stages may be flexibly configured according to demand, and the embodiment of the present application does not limit this.

[0132] The above is only an optional implementation method for some implementation scenarios of the present application. It should be pointed out that for ordinary technicians in this technical field, without departing from the technical concept of the solution of the present application, other similar implementation methods based on the technical ideas of the present application are also within the protection scope of the embodiments of the present application.

Claims

1. A three-phase load combined preloading construction method based on handover surface elevation control, characterized in that: include: A horizontal drainage layer is formed above a target site, and a drainage board is inserted into the target site, wherein the foundation of the target site is a soft soil foundation, and the top of the drainage board is buried in the horizontal drainage layer; forming a vacuum layer on a side of the horizontal drainage layer away from the target site, and using the vacuum layer to perform vacuuming; Determine that vacuuming is completed, construct a loading layer and a water loading layer above the vacuuming layer, the water loading layer is located above the loading layer, and the heights of the loading layer and the water loading layer correspond to the elevation of the handover surface of the target site; Determine that the unloading conditions are met, remove the water load layer, construct the stack load layer by vibration, and clean up the target site. The unloading conditions include at least one of standing for a preset time and a daily settlement rate less than a preset settlement value.

2. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 1 is characterized in that: The horizontal drainage layer includes a first drainage layer and a second drainage layer, and forming the horizontal drainage layer above the target site includes: Cleaning the target site, and laying preset materials on the target site, wherein the preset materials include geotextiles; Laying medium-coarse sand with a first thickness on the preset material to form a sand cushion layer, and determining the sand cushion layer as the first drainage layer; The step of inserting the drainage board into the target site comprises: Inserting the drainage board into the target site by using a board inserting machine, so that the top of the drainage board exposes the first drainage layer; It is determined that the insertion of the drain board is completed, and medium-coarse sand is laid according to the exposed height of the drain board to form the second drainage layer, and the top of the drain board is buried in the second drainage layer.

3. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 2 is characterized in that: The step of forming a vacuum layer on a side of the horizontal drainage layer away from the target site comprises: Laying a vacuum main pipe and a filter pipe above the medium-coarse sand embedded in the drainage board, and setting a vacuum extraction system outside the target site; The preset material and the sealing film are laid in sequence on the vacuum main pipe and the filter tube, and the sealing film is pressed into the film pressing groove.

4. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 2 is characterized in that: The formation of the stacking layer comprises: Laying a first preset number of layers of the preset material on the vacuum layer; The thickness of the loading layer is obtained, and soil is filled according to the thickness and preset settlement conditions to form the loading layer. The preset settlement conditions include a surface settlement rate that is less than or equal to a first preset value per day and night.

5. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 2 is characterized in that: The formation of the water-bearing layer comprises: The water load layer located on the first waterproof material is formed according to a second preset height, the water load layer is formed by a water load, the arrangement of the water load includes at least one of a water bag, a water tank, and a water cofferdam, and the first waterproof material includes an impermeable geomembrane.

6. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 5 is characterized in that: The step of forming the water-bearing layer on the first waterproof material according to the second preset height comprises: The water load height of the water load layer is obtained, a target water load is determined according to the water load height and the second preset height, and the water load layer is formed by using the first waterproof material and the target water load.

7. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 1 is characterized in that: The target water load is a water cofferdam, and forming the water load layer by using the first waterproof material and the target water load includes: A cofferdam having a third preset height is built around the target site, wherein the cross-sectional shape of the cofferdam corresponds to the height and bulk density of the water load layer, and the third preset height is greater than the water load height; A third preset number of layers of second waterproof material are laid and fixed in the cofferdam, and water is injected into the water-containing space formed by the second waterproof material to form the water-loading layer.

8. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 1 is characterized in that: The heights of the stacking layer and the water loading layer satisfy formula (1): p=γ s h1+γ w h2(1), where p represents the upper load, γ w represents the bulk density of water in the water-loading layer, γ s It represents the bulk density of the stockpile in the stockpile layer, h1 is the height of the stockpile layer, and h2 is the height of the water-loading layer.

9. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 8 is characterized in that: The heights of the pile load layer and the water load layer are calculated by formulas (1), (2) and (3), wherein formulas (2) and (3) are respectively: h1=H-h+s+s1 (2) s1=m v ·c w h2·h1 (3) Where H represents the delivery surface elevation, h is the delivery surface elevation of the target site, s is the settlement of the target site during construction, s1 is the additional consolidation of the loading layer, m v is the additional consolidation coefficient.

10. The three-phase load combined preloading construction method based on handover surface elevation control according to claim 1 is characterized in that: The vibrating and tamping construction of the loading layer comprises: Vibration tamping construction is performed on the loading layer, and the vibration tamping construction includes spot tamping and full tamping. The tamping point of the vibration tamping construction is determined according to the position of the drainage board.

11. A three-phase load combined preloading construction system based on handover surface elevation control, characterized in that: The system includes construction equipment, and the construction equipment includes drainage boards. The system implements the three-phase load combined preloading construction method based on handover surface elevation control as described in any one of claims 1 to 10 through the construction equipment.

12. The three-phase load combined preloading construction system based on handover surface elevation control according to claim 11 is characterized in that: The construction equipment includes sensors and a computer processing terminal, wherein the sensors include a pore water pressure gauge, a displacement sensor and a vacuum pressure gauge; The pore water pressure gauge is buried in the soil layer of the target site, the vacuum pressure gauge is buried in the horizontal drainage layer, and the displacement sensor is buried at the bottom of the heap layer and the top of the heap layer; The computing and processing terminal is connected to the sensor. After determining that the vacuum is drawn, the computing and processing terminal obtains the data collected by the sensor and draws a sedimentation time course curve according to the data.

13. The three-phase load combined preloading construction system based on handover surface elevation control according to claim 12 is characterized in that: The displacement sensor includes a first displacement sensor and a second displacement sensor. The first displacement sensor is buried at the bottom of the loading layer, and the second displacement sensor is buried at the top of the loading layer. After the construction of the loading layer is completed, the second displacement sensor starts working and uploads data to the computer processing terminal.

14. The three-phase load combined preloading construction system based on handover surface elevation control according to claim 13 is characterized in that: The embedding of the sensor includes: After the drainage board is installed, bury the pore water pressure gauge; After the horizontal drainage layer is laid, bury the vacuum pressure gauge; A first displacement sensor is buried above the vacuum layer, and a second displacement sensor is buried after the construction of the loading layer is completed.

15. The three-phase load combined preloading construction system based on handover surface elevation control according to claim 12 is characterized in that: The construction equipment also includes a water pump and a water storage container for storing water, wherein the water pump is used to inject water from the water storage container into the water load or inject water from the water load into the water storage container; The water pump is used to inject water into or pump water out of the water load; When the water load layer is formed, the working time of the water pump is determined by formula (4); In the formula, t is the working time, n represents the number of water loads, S is the bottom area of ​​the water load, h2 is the height of the water load layer, and v represents the pumping speed of the water pump.

16. The three-phase load combined preloading construction system based on handover surface elevation control according to claim 15 is characterized in that: The formation of the water load includes: Using water load to form a water load layer, obtaining a current consolidation degree calculation curve corresponding to the current settlement time history curve, and generating an error between the current consolidation degree calculation curve and a preset consolidation degree calculation curve; The water pump is controlled to inject water into or pump water out of the water load according to the error.

Images