Method for predicting soil consolidation degree and settlement using horizontal drainage boards combined with vacuum preloading

Abstract

This invention provides a method for predicting the degree of consolidation and settlement of soil using a horizontal drainage board combined with vacuum preloading. By acquiring the basic parameters of the target soil, the design parameters of the target project, and the vacuum front height, the average pore pressure is calculated based on the consolidation coefficient, water unit weight, initial hydraulic gradient, vacuum load magnitude, maximum drainage distance, and vacuum front height. The average degree of consolidation of the target soil is then calculated by combining the average pore pressure and the vacuum load magnitude. Finally, the settlement of the target soil is calculated by combining the average pore pressure, initial void ratio, compression index, initial effective stress, and maximum drainage distance. This invention can effectively predict the average degree of consolidation and settlement of soil subjected to drainage and consolidation treatment using a horizontal drainage board under vacuum conditions. The prediction results can provide a theoretical basis for the design method of using horizontal drainage boards to treat river silt.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of soil drainage consolidation research technology, and more specifically, the embodiments of the present invention relate to a method for predicting the degree of soil consolidation and settlement using a horizontal drainage board combined with vacuum preloading. Background Technology

[0002] This section is intended to provide background or context for embodiments of the invention set forth in the claims. The description herein may include concepts that may be explored, but not necessarily concepts that have been previously conceived or explored. Therefore, unless otherwise stated, what is described in this section is not prior art for the purposes of this application's specification and claims, and is not acknowledged as prior art simply by virtue of its inclusion in this section.

[0003] Hydraulic fill is a type of artificial fill formed by hydraulically filling mud and sand, and it is one of the most common types of artificial fill along my country's coast. Hydraulic fill foundations have low bearing capacity and slow strength growth; they are prone to uneven deformation under load; they exhibit high deformation rates and long stabilization times; and they possess characteristics of low permeability, thixotropy, and high rheology. Therefore, hydraulic fill foundations cannot be used directly and require drainage treatment to accelerate soil consolidation.

[0004] The method of using precast drainage boards combined with vacuum preloading for drainage consolidation of dredged fill is widely used due to its economy and effectiveness. This method can be divided into vertical drainage board (PVD) and horizontal drainage board (PHD) methods based on the direction of drainage board placement. Compared with the PVD method, the PHD method allows for layered placement of horizontal drainage boards in the treatment site, saving labor and improving treatment efficiency. Furthermore, the horizontal drainage boards can move freely downwards with the soil, avoiding significant bending, and the vacuum pressure can be transmitted more evenly and effectively within the horizontal drainage boards, resulting in better treatment effects. In addition, the combination of horizontal drainage boards and vacuum preloading offers advantages such as convenient construction management, economic practicality, and labor savings. Moreover, the use of horizontal drainage boards can increase the treatment capacity, meaning the amount of dredged sludge treated can exceed the volume of the treatment site. Finally, the dredging and preloading drainage processes can occur simultaneously, further improving the soil consolidation efficiency.

[0005] Therefore, horizontal drainage boards combined with vacuum preloading is an efficient, economical, and environmentally friendly method for soil drainage consolidation. However, there is currently no theoretical model that can accurately describe the consolidation behavior of horizontal drainage boards combined with vacuum preloading. It is impossible to reasonably predict the average consolidation rate and settlement of silt treated by horizontal drainage boards under vacuum conditions. As a result, the current design method for treating river silt by horizontal drainage boards combined with vacuum preloading lacks a corresponding theoretical basis. Summary of the Invention

[0006] Existing technologies for soil consolidation using horizontal drainage boards combined with vacuum preloading suffer from the aforementioned drawbacks. Therefore, a method for predicting soil consolidation degree and settlement using horizontal drainage boards combined with vacuum preloading is urgently needed to address at least one of these drawbacks.

[0007] In this context, embodiments of the present invention aim to provide a method for predicting soil consolidation and settlement using a horizontal drainage board combined with vacuum preloading.

[0008] In a first aspect of the present invention, a method for predicting the degree of consolidation of soil using a horizontal drainage board combined with vacuum preloading is provided, comprising:

[0009] The basic parameters of the target soil, the design parameters of the target project, and the height of the vacuum front are obtained. The basic parameters of the target soil include: consolidation coefficient, unit weight of water, and initial hydraulic gradient. The design parameters of the target project include: vacuum load magnitude and maximum drainage distance.

[0010] The average pore pressure is calculated based on the consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance, and the height of the vacuum front.

[0011] The average degree of consolidation of the target soil is calculated by combining the average pore pressure and the magnitude of the vacuum load.

[0012] In one embodiment, the formula for calculating the average degree of consolidation of the target soil is: In the formula, denoted as average pore pressure, p as the magnitude of vacuum load, and U as the average degree of consolidation of the target soil.

[0013] In another embodiment, the calculation process of the average pore pressure includes: first, calculating the corresponding consolidation time based on the consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance, and the height of the vacuum front; and then, combining the consolidation time with the consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance, and the height of the vacuum front, to calculate the average pore pressure.

[0014] In another embodiment, the formula for calculating the average pore pressure is: In the formula, where i is the average pore pressure, i0 is the initial hydraulic gradient, and γ is the average pore pressure. w For the specific gravity of water, Z f Where p is the height of the vacuum front, H is the magnitude of the vacuum load, and c is the maximum drainage distance. v t is the consolidation coefficient and t is the consolidation time.

[0015] In yet another embodiment, the formula for calculating the consolidation time is: In the formula, t is the consolidation time.

[0016] In a second aspect of the present invention, a method for predicting soil settlement using a horizontal drainage board combined with vacuum preloading is provided, comprising:

[0017] The basic parameters of the target soil, the design parameters of the target project, and the height of the vacuum front are obtained. The basic parameters of the target soil include: consolidation coefficient, unit weight of water, initial hydraulic gradient, initial void ratio, compression index, and initial effective stress. The design parameters of the target project include: vacuum load magnitude and maximum drainage distance.

[0018] The average pore pressure is calculated based on the consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance, and the height of the vacuum front.

[0019] The settlement of the target soil is calculated by combining the average pore pressure, the initial void ratio, the compression index, the initial effective stress, and the maximum drainage distance.

[0020] In one embodiment, the formula for calculating the settlement of the target soil is: In the formula, S t For the magnitude of the settlement of the target soil, c c Where is the compressibility index, H is the maximum drainage distance, e0 is the initial void ratio, and p0 is the initial effective stress. The average pore pressure is denoted as .

[0021] In another embodiment, the calculation process of the average pore pressure includes: first, calculating the corresponding consolidation time based on the consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance, and the height of the vacuum front; and then, combining the consolidation time with the consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance, and the height of the vacuum front, to calculate the average pore pressure.

[0022] In yet another embodiment, the formula for calculating the average pore pressure is: In the formula, where i is the average pore pressure, i0 is the initial hydraulic gradient, and γ is the average pore pressure. w For the specific gravity of water, Z f Where p is the height of the vacuum front, H is the magnitude of the vacuum load, and c is the maximum drainage distance. v t is the consolidation coefficient and t is the consolidation time.

[0023] In another embodiment, the formula for calculating the consolidation time is: In the formula, t is the consolidation time.

[0024] The beneficial effects of this invention include: This invention provides a method for predicting the degree of soil consolidation by combining a horizontal drainage board with vacuum preloading, considering the initial hydraulic gradient, and also provides a method for predicting soil settlement by combining a horizontal drainage board with vacuum preloading, considering the initial hydraulic gradient. It can effectively predict the average degree of consolidation and the magnitude of settlement of soil treated by horizontal drainage board under vacuum conditions. The prediction results can provide a theoretical basis for the design method of treating river silt by horizontal drainage board. Attached Figure Description

[0025] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent from the following detailed description taken in conjunction with the accompanying drawings. Several embodiments of the invention are illustrated in the drawings by way of example and not limitation, wherein:

[0026] Figure 1 This is a schematic diagram of an existing technology for treating high-moisture-content sludge using a combination of horizontal drainage boards and vacuum preloading.

[0027] Figure 2 A flowchart illustrating a method 200 for predicting the degree of consolidation of soil using a horizontal drainage board combined with vacuum preloading according to an embodiment of the present invention is shown.

[0028] Figure 3 A flowchart of a method 300 for predicting soil settlement using a horizontal drainage board combined with vacuum preloading, according to another embodiment of the present invention, is shown schematically.

[0029] Figure 4 The diagram illustrates the variation of the average degree of consolidation U with consolidation time t according to an embodiment of the present invention.

[0030] Figure 5 The soil settlement s according to an embodiment of the present invention is illustrated schematically. t Graph showing the change with consolidation time t;

[0031] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts. Detailed Implementation

[0032] The principles and spirit of the invention will now be described with reference to several exemplary embodiments. It should be understood that these embodiments are given merely to enable those skilled in the art to better understand and implement the invention, and are not intended to limit the scope of the invention in any way. Rather, these embodiments are provided to make this disclosure more thorough and complete, and to fully convey the scope of this disclosure to those skilled in the art.

[0033] According to an embodiment of the present invention, a method for predicting soil consolidation degree and settlement using a horizontal drainage board combined with vacuum preloading is proposed. Furthermore, any quantity of elements in the accompanying drawings is for illustrative purposes only and not for limitation, and any naming is for distinction only and has no limiting meaning.

[0034] The principles and spirit of the present invention will be explained in detail below with reference to several representative embodiments.

[0035] This invention addresses the widely used method of soil drainage consolidation using horizontal drainage boards combined with vacuum preloading (see schematic diagram). Figure 1 As shown, this paper presents a method for predicting the degree of soil consolidation and the degree of soil settlement by combining a horizontal drainage board with vacuum preloading, which takes into account the initial hydraulic gradient. This method can effectively predict the average degree of soil consolidation and the magnitude of soil settlement under vacuum conditions. The prediction results can provide a theoretical basis for the design method of horizontal drainage board for treating river silt.

[0036] After introducing the basic principles of the present invention, various non-limiting embodiments of the present invention will be described in detail below.

[0037] The following is for reference. Figure 2 This invention describes a method for predicting the degree of soil consolidation using a horizontal drainage board combined with vacuum preloading, according to an exemplary embodiment of the present invention. It should be noted that the embodiments of the present invention can be applied to any applicable scenario; the method described in this invention can be used in any application scenario involving the calculation of the degree of soil consolidation under a horizontal drainage board combined with vacuum preloading method.

[0038] Figure 2 A flowchart of a method 200 for predicting the degree of consolidation of soil using a horizontal drainage board combined with vacuum preloading according to an embodiment of the present invention is shown schematically, including steps S201, S202 and S203.

[0039] In step S201, the basic parameters of the target soil, the design parameters of the target project, and the height of the vacuum front are obtained;

[0040] The basic parameters of the target soil include: consolidation coefficient c. v γ-water w The initial hydraulic gradient i0; the design parameters of the target project include: vacuum load magnitude p and maximum drainage distance H; vacuum front height Z. f These are a series of values ​​given in advance for the target project.

[0041] As an example, the basic parameters of the target soil can be determined through geological survey reports and laboratory experiments, and the design parameters of the target project can be determined through investigation of engineering design schemes. Since the methods for determining the basic parameters of the target soil and the design parameters of the target project are existing technologies, they will not be elaborated on here.

[0042] In step S202, the average pore pressure is calculated based on the consolidation coefficient, water unit weight, initial hydraulic gradient, vacuum load magnitude, maximum drainage distance, and vacuum front height obtained in step S201.

[0043] In this embodiment, the calculation process for the average pore pressure includes:

[0044] (1) First, the corresponding consolidation time is calculated based on the consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance, and the height of the vacuum front.

[0045] The formula for calculating the consolidation time is as follows:

[0046]

[0047] In the formula, t is the consolidation time, i0 is the initial hydraulic gradient, and γ is the initial hydraulic gradient. w For the specific gravity of water, Z f Where p is the height of the vacuum front, H is the magnitude of the vacuum load, and c is the maximum drainage distance. v is the consolidation coefficient.

[0048] As can be seen from the formula for calculating consolidation time, once the basic parameters of the target soil and the design parameters of the target project are determined, the consolidation time t and the vacuum front height Z... f There is a one-to-one correspondence between them. In this embodiment, the height Z of the vacuum front is determined based on a graphical method. f The relationship between the time and the consolidation time t.

[0049] (2) Then, the average pore pressure is calculated by combining the consolidation time and consolidation coefficient, the specific weight of water, the initial hydraulic gradient, the magnitude of the vacuum load, the maximum drainage distance and the height of the vacuum front.

[0050] The formula for calculating the average pore pressure is as follows:

[0051]

[0052] In the formula, where i is the average pore pressure, i0 is the initial hydraulic gradient, and γ is the average pore pressure. w For the specific gravity of water, Z f Where p is the height of the vacuum front, H is the magnitude of the vacuum load, and c is the maximum drainage distance. v t is the consolidation coefficient and t is the consolidation time.

[0053] In this embodiment, the formula for calculating the average pore pressure is determined based on the definition of average pore pressure.

[0054] In step S203, the average degree of consolidation of the target soil is calculated by combining the average pore pressure and the magnitude of the vacuum load.

[0055] In this embodiment, the formula for calculating the average degree of consolidation of the target soil is:

[0056]

[0057] In the formula, denoted as average pore pressure, p as the magnitude of vacuum load, and U as the average degree of consolidation of the target soil.

[0058] In summary, this embodiment determined the consolidation time t and the vacuum front height Z. f An explicit function between the two is proposed, and based on this explicit function, a method for predicting the degree of soil consolidation in combination with vacuum preloading and horizontal drainage boards that considers the initial hydraulic gradient is provided. This method can effectively predict the average degree of soil consolidation under vacuum conditions by horizontal drainage boards. The prediction results can provide a theoretical basis for the design method of horizontal drainage boards for treating river silt.

[0059] The following is for reference. Figure 3 This invention describes a method for predicting soil settlement using a horizontal drainage board combined with vacuum preloading, according to an exemplary embodiment of the present invention. It should be noted that the embodiments of the present invention can be applied to any applicable scenario; the method described in this invention can be used in any application scenario involving the calculation of soil settlement under a horizontal drainage board combined with vacuum preloading method.

[0060] Figure 3 A flowchart of a method 300 for predicting soil settlement using a horizontal drainage board combined with vacuum preloading according to an embodiment of the present invention is shown schematically, including steps S301, S302 and S303.

[0061] In step S301, the basic parameters of the target soil, the design parameters of the target project, and the height of the vacuum front are obtained;

[0062] The basic parameters of the target soil include: consolidation coefficient c. v γ-water w Initial hydraulic gradient i0, initial void ratio e0, compressibility index c c Initial effective stress p0; Design parameters of the target project include: vacuum load magnitude p and maximum drainage distance H; Vacuum front height Z. f These are a series of values ​​given in advance for the target project.

[0063] As an example, the basic parameters of the target soil can be determined through geological survey reports and laboratory experiments, and the design parameters of the target project can be determined through investigation of engineering design schemes. Since the methods for determining the basic parameters of the target soil and the design parameters of the target project are existing technologies, they will not be elaborated on here.

[0064] In step S302, the average pore pressure is calculated based on the consolidation coefficient, water unit weight, initial hydraulic gradient, vacuum load magnitude, maximum drainage distance, and vacuum front height obtained in step S301.

[0065] The calculation process of average pore pressure in this embodiment is the same as that in step S202 above, and will not be repeated here.

[0066] In step S303, the settlement of the target soil is calculated by combining the average pore pressure, initial void ratio, compression index, initial effective stress, and maximum drainage distance.

[0067] In this embodiment, the formula for calculating the settlement of the target soil is:

[0068]

[0069] In the formula, S t For the magnitude of the settlement of the target soil, c c Where is the compressibility index, H is the maximum drainage distance, e0 is the initial void ratio, and p0 is the initial effective stress. The average pore pressure is denoted as .

[0070] In summary, this embodiment provides a method for predicting soil settlement by combining a horizontal drainage board with vacuum preloading, taking into account the initial hydraulic gradient. This method can effectively predict the magnitude of soil settlement under vacuum conditions when the soil is drained and consolidated by a horizontal drainage board. The prediction results can provide a theoretical basis for the design method of treating river silt with a horizontal drainage board.

[0071] The effectiveness of the method of the present invention will be verified through specific application examples below.

[0072] In a specific application scenario, the basic parameters of the target soil, determined through geological survey reports and laboratory experiments, are: consolidation coefficient c. v =0.0005m 2 / day, initial void ratio e0 = 2.3, compressibility index c c =1.2, Specific weight of water γ w =10kN / m 3The initial hydraulic gradient i0 = 10 and the initial effective stress p0 = 2 kPa. Through investigation of the engineering design scheme, the design parameters of the target project are determined to be: vacuum load p = 80 kPa and maximum drainage distance H = 0.3 m.

[0073] The target project has a pre-defined vacuum front height Z. f As shown in the first column of Table 1, based on the basic parameters of the target soil and the target engineering design parameters obtained above, the consolidation time can be calculated one by one using the formula for calculating the height Z of each vacuum front. f The corresponding consolidation time t is calculated, and the results are shown in the second column of Table 1.

[0074] Using the formula for calculating average pore pressure, the average pore pressure corresponding to each consolidation time t can be obtained. The calculation results are shown in the third column of Table 1.

[0075] Using the formula for calculating the average degree of consolidation of the target soil, the average pore pressure can be calculated. The corresponding average degree of consolidation U of the target soil is calculated and shown in the fourth column of Table 1. The change of the average degree of consolidation U with consolidation time t is as follows: Figure 4 As shown.

[0076] Using the formula for calculating the settlement of the target soil, the relationship between the average pore pressure and the target soil mass can be determined. The corresponding soil settlement size S t The calculation results are shown in the fifth column of Table 1, showing the soil settlement S. t The change with consolidation time t is as follows Figure 5 As shown.

[0077] Table 1. Prediction Results of Soil Consolidation Degree and Soil Settlement

[0078]

[0079]

[0080]

[0081] Those skilled in the art will recognize that embodiments of the present invention can be implemented as a system, method, or computer program product. Therefore, this disclosure can be specifically implemented as entirely hardware, entirely software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, generally referred to herein as a "circuit," "module," "unit," or "system." Furthermore, in some embodiments, the present invention can also be implemented as a computer program product contained in one or more computer-readable media, which includes computer-readable program code.

[0082] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example,, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (not exhaustive) of a computer-readable storage medium may include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0083] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber, RF, etc., or any suitable combination thereof.

[0084] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network (including a local area network (LAN) or a wide area network (WAN)), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0085] These computer program instructions can be stored in a computer-readable medium that enables a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable medium produce a product comprising an instruction apparatus that implements the functions / operations specified in the boxes of a flowchart and / or block diagram.

[0086] Computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, such that the instructions that execute on the computer or other programmable apparatus can provide a process for implementing the functions / operations specified in the boxes of a flowchart and / or block diagram.

[0087] It should be noted that although several steps of the method for predicting soil consolidation and settlement using horizontal drainage boards combined with vacuum preloading have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of the present invention, the features and functions of two or more steps described above can be embodied in one step. Conversely, the features and functions of one step described above can be further divided and embodied by multiple steps.

[0088] Furthermore, although the operations of the method of the present invention are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all of the operations shown must be performed to achieve the desired result. Rather, the steps depicted in the flowchart may be performed in a different order. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0089] The use of the verbs "including" and "contains" and their inflections in the application documents does not preclude the existence of elements or steps other than those described in the application documents. The article "a" or "one" preceding an element does not preclude the existence of multiple such elements.

[0090] While the spirit and principles of the invention have been described with reference to several specific embodiments, it should be understood that the invention is not limited to the disclosed specific embodiments, and the division of aspects does not imply that features in these aspects cannot be combined for benefit; such division is merely for ease of description. The invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the appended claims is to be interpreted in the broadest sense, thereby encompassing all such modifications and equivalent structures and functions.

Claims

1. A method for predicting the degree of consolidation of soil by horizontal drain combined vacuum preloading, characterized by, The method comprises the following steps: obtaining basic parameters of a target soil, design parameters of a target project and a vacuum front line height; the basic parameters of the target soil include a consolidation coefficient, a water specific weight and an initial hydraulic gradient; the design parameters of the target project include a vacuum load size and a maximum drainage distance; an average pore pressure is calculated according to the consolidation coefficient, the water specific weight, the initial hydraulic gradient, the vacuum load size, the maximum drainage distance and the vacuum front line height; an average consolidation degree of the target soil is calculated according to the average pore pressure and the vacuum load size, the average consolidation degree of the target soil is calculated according to the following formula: ； In the formula, is the average pore pressure, p is the magnitude of the vacuum load, and U is the average degree of consolidation of the target soil. the calculation process of the average pore pressure comprises the following steps: first, a corresponding consolidation time is calculated according to the consolidation coefficient, the water specific weight, the initial hydraulic gradient, the vacuum load size, the maximum drainage distance and the vacuum front line height; then, the average pore pressure is calculated according to the consolidation time and the consolidation coefficient, the water specific weight, the initial hydraulic gradient, the vacuum load size, the maximum drainage distance and the vacuum front line height, the calculation formula of the average pore pressure is as follows: ； wherein is the average pore pressure, i0is the initial hydraulic gradient, is the specific weight of water, Z f is the vacuum lift, p is the magnitude of the vacuum load, H is the maximum drainage distance, c v is the coefficient of consolidation, t is the consolidation time, the calculation formula of the consolidation time is as follows: ； wherein, t is the consolidation time.

2. A method for predicting soil settlement by horizontal drain combined vacuum preloading, characterized by, The method comprises the following steps: obtaining basic parameters of a target soil, design parameters of a target project and a vacuum front line height; the basic parameters of the target soil include a consolidation coefficient, a water specific weight, an initial hydraulic gradient, an initial void ratio, a compression index and an initial effective stress; the design parameters of the target project include a vacuum load size and a maximum drainage distance; an average pore pressure is calculated according to the consolidation coefficient, the water specific weight, the initial hydraulic gradient, the vacuum load size, the maximum drainage distance and the vacuum front line height; a settlement size of the target soil is calculated according to the average pore pressure and the initial void ratio, the compression index, the initial effective stress and the maximum drainage distance, the calculation formula of the settlement size of the target soil is as follows: ； In the formula, S t is the settlement size of the target soil body, c c is the compression index, H is the maximum drainage distance, e0 is the initial void ratio, p0 is the initial effective stress, is the average pore pressure, the calculation process of the average pore pressure comprises the following steps: first, a corresponding consolidation time is calculated according to the consolidation coefficient, the water specific weight, the initial hydraulic gradient, the vacuum load size, the maximum drainage distance and the vacuum front line height; then, the average pore pressure is calculated according to the consolidation time and the consolidation coefficient, the water specific weight, the initial hydraulic gradient, the vacuum load size, the maximum drainage distance and the vacuum front line height, the calculation formula of the average pore pressure is as follows: ； wherein is the average pore pressure, i0is the initial hydraulic gradient, is the specific weight of water, Z f is the vacuum lift, p is the magnitude of the vacuum load, H is the maximum drainage distance, c v is the coefficient of consolidation, t is the consolidation time, the calculation formula of the consolidation time is as follows: ； wherein, t is the consolidation time.

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