Critical height calculation method for pile cap beam supporting type embankment

Abstract

The embodiment of the invention provides a critical height calculation method for a pile cap beam supporting type embankment. The vertical stress of the pile cap beam supporting type embankment at the given depth is calculated by utilizing a vertical stress calculation formula by obtaining soil filling parameters, pile distribution design parameters and roadbed top surface design load of the pile cap beam supporting type embankment. The method comprises the following steps: obtaining soil filling parameters, pile distribution design parameters, roadbed top surface design load and actual soil filling height of a pile cap beam supporting type embankment, calculating by utilizing a critical height calculation formula to obtain a theoretical critical height of an equal sinking surface, and correcting the theoretical critical height of the equal sinking surface in combination with the actual soil filling height of the pile cap beam supporting type embankment. And obtaining the actual critical height of the equal sinking surface. According to the method, the equivalent sinking face boundary height is related to the filling parameters and pile arrangement design parameters of the embankment and is also positively related to the actual filling height of the embankment and the design load of the top face of the roadbed, so that the calculation of the equivalent sinking face boundary height is more accurate.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field of soil arching effect research of pile cap beam supported embankment, and more particularly, to a critical height calculation method for pile cap beam supported embankment. BACKGROUND

[0002] This section is intended to provide background information to facilitate a better understanding of embodiments of the application recited in the claims. The description herein can include concepts that can be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, that which is described in this section is not prior art to the claims and will not be read to call into question anything that is described in this section for prior art purposes.

[0003] In the long-term accumulation of domestic engineering projects, it is found that the pile-supported yield zone has a certain risk of instability when used in deep soft soil foundation, especially in deep soft soil foundation treatment with missing hard crust layer, under the condition of meeting the overall stability calculation. In addition to overall stability failure, rigid pile composite foundation in deep soft soil may also occur "flowing sliding failure". Pile beam (PB) composite foundation and pile cap beam (PCB) composite foundation scheme can be used to promote the development of soil arching effect, increase the lateral stiffness of pile top and the bending strength of rigid pile, so as to take advantage of the vertical bearing capacity of rigid pile composite foundation. The ground beam structure or pile cap-ground beam structure is similar to the rigid raft structure set at the top of the pile, which cannot directly increase the bearing capacity of the foundation, but can promote the development of the bearing capacity of the rigid pile composite foundation by promoting the transfer of fill load to the pile top (soil arching effect), increasing the lateral stiffness of the pile top and the bending strength of the pile, and controlling the uneven settlement of the pile top.

[0004] Through in-situ observation and research of the pile cap beam structure (PCB structure for short) composite yield zone by entity engineering, the results show that the PCB structure has obvious effect in reducing the lateral displacement of the foundation, the overall settlement and uneven settlement of the pile and the soil around the pile, and therefore it is considered that the composite yield zone of the PCB structure is very effective in improving the stability of the yield zone. In the rigid pile composite foundation, the settlement of the soil at the top of the foundation is often greater than that at the top of the pile. This uneven settlement causes shear stress in the embankment fill, which transfers the vertical stress from the soil between the piles to the top of the pile. This load transfer phenomenon is called soil arching effect. Research on the soil arching effect of the PCB structure can help designers to determine the load sharing ratio or stress reduction rate of the pile-supported composite foundation, so as to more accurately determine the required bearing capacity of the foundation pile and the size and stiffness of the ground beam structure.

[0005] However, there are few studies on the load transfer mechanism of the PCB structure at present, and the soil arching under the condition of equilateral triangle pile arrangement and circular pile cap is also relatively less studied. Although it is generally believed that the critical height of the equal settlement surface (the height from the equal settlement surface to the top of the subgrade or the top of the pile cap) is related to many factors (such as the filling parameters of the embankment, the pile spacing, etc.), the current formula for calculating the critical height of the equal settlement surface basically only depends on the pile spacing or the net pile spacing, which will cause a large deviation between the theoretical value and the actual value of the soil arching effect under certain working conditions. In addition, there are some calculation methods that use a fixed critical height, and the deviation between the theoretical value and the experimental value of the tensile stress on the top of the subgrade and the stress reduction rate is large when the filling height is high. SUMMARY

[0006] In the prior art, the soil arching effect of the pile cap beam supported embankment has the above many drawbacks. Therefore, there is a great need for a critical height calculation method for the pile cap beam supported embankment to at least solve one of the above many drawbacks.

[0007] In the present context, embodiments of the present application aim to provide a vertical stress and critical height calculation method for a pile cap beam supported embankment.

[0008] In a first aspect of the embodiments of the present application, a vertical stress calculation method for a pile cap beam supported embankment is provided, comprising: obtaining the filling parameters of the pile cap beam supported embankment, the pile arrangement design parameters and the subgrade top surface design load; the filling parameters include the cohesion, the internal friction angle and the unit weight of each soil layer in the embankment; the pile arrangement design parameters include the pile arrangement mode, the pile spacing, the pile cap radius and the beam width; the pile arrangement mode is equilateral triangle pile arrangement; according to the filling parameters, the pile arrangement design parameters and the subgrade top surface design load, the vertical stress of the pile cap beam supported embankment at a given depth is calculated by using a vertical stress calculation formula; the vertical stress calculation formula is a relationship between the vertical stress of the pile cap beam supported embankment and its filling parameters, pile arrangement design parameters, subgrade top surface design load and embankment depth.

[0009] In one embodiment, the vertical stress calculation formula is: , wherein Z is the embankment depth, σz is the vertical stress of the pile cap beam supported embankment at the depth Z, γ is the unit weight of the soil, c, are the cohesion and the internal friction angle of the filling respectively, K0 is the lateral pressure coefficient of the soil, Q is the subgrade top surface design load, P is the area of the vertical projection of the yield region of the pile cap beam structure, and G is the perimeter of the yield region of the pile cap beam structure.

[0010] In another embodiment, the lateral pressure coefficient K0 of the soil is: .

[0011] In yet another embodiment, the area P of the vertical projection of the yielding zone of the pile cap beam structure is: where D is the pile spacing, r is the pile cap radius, and w is the width of the ground beam.

[0012] In still another embodiment, the perimeter G of the yielding zone of the pile cap beam structure is: .

[0013] In a second aspect of the embodiments of the present application, a method for calculating the critical height of a pile cap beam supported embankment is provided, comprising: obtaining the filling parameters, the pile arrangement design parameters, the design load of the subgrade top surface, and the actual filling height of the pile cap beam supported embankment; the filling parameters include the cohesion, the internal friction angle, and the unit weight of each soil layer in the embankment; the pile arrangement design parameters include the pile arrangement mode, the pile spacing, the pile cap radius, and the width of the ground beam; the pile arrangement mode is the equilateral triangle pile arrangement; calculating the theoretical critical height of the equal settlement surface by using a critical height calculation formula according to the filling parameters, the pile arrangement design parameters, the design load of the subgrade top surface, and the actual filling height; the critical height calculation formula is a relationship between the critical height of the equal settlement surface of the pile cap beam supported embankment and the filling parameters, the pile arrangement design parameters, the design load of the subgrade top surface, and the actual filling height; correcting the theoretical critical height of the equal settlement surface in combination with the actual filling height of the pile cap beam supported embankment to obtain the actual critical height of the equal settlement surface.

[0014] In one embodiment, the critical height calculation formula is: where h f is the theoretical critical height of the equal settlement surface, P is the area of the vertical projection of the yielding zone of the pile cap beam structure, G is the perimeter of the yielding zone of the pile cap beam structure, K0 is the lateral pressure coefficient of the soil, γ is the unit weight of the soil, c and φ are respectively the cohesion and the internal friction angle of the filling, Q is the design load of the subgrade top surface, and h is the actual filling height of the pile cap beam supported embankment.

[0015] In another embodiment, the correcting the theoretical critical height of the equal settlement surface in combination with the actual filling height of the pile cap beam supported embankment comprises: if the theoretical critical height of the equal settlement surface is less than the actual filling height, the actual critical height of the equal settlement surface is equal to the theoretical critical height of the equal settlement surface; and if the theoretical critical height of the equal settlement surface is greater than the actual filling height, the actual critical height of the equal settlement surface is equal to the actual filling height.

[0016] In yet another embodiment, the lateral pressure coefficient K0 of the soil is: .

[0017] In still another embodiment, the area P of the vertical projection of the yielding zone of the pile cap beam structure is: , and the perimeter G of the yielding zone of the pile cap beam structure is: ​where D is the pile spacing, r is the pile cap radius, and w is the beam width.

[0018] The beneficial effects of the present application include: the present application obtains a vertical stress calculation method of a pile cap beam supported embankment at any depth under the condition of equilateral triangle pile arrangement and circular pile cap by studying the load transfer mechanism of the pile cap beam structure.

[0019] Further, the present application further proposes relevant elements for determining the critical height of the equal settlement surface of the pile cap beam supported embankment, i.e., it is proposed that the critical height of the equal settlement surface is positively correlated with the actual filling height of the embankment and the design load of the subgrade top surface in addition to the filling parameters of the embankment and the pile arrangement design parameters. Compared with the critical height calculation method of the equal settlement surface in the prior art which only considers the pile spacing or the net pile spacing, the critical height of the equal settlement surface calculated by the present application is more accurate.

[0020] In addition, since the present application considers the influence of the actual filling height of the embankment when calculating the critical height of the equal settlement surface, compared with the calculation method of the prior art which uses a fixed critical height, the problem that the tensile stress of the subgrade top surface and the deviation of the theoretical value and the test value of the stress reduction rate are large when the filling height of the embankment is high can be reduced.

[0021] Meanwhile, the present application only uses the embankment filling parameters, the pile arrangement design parameters, the filling height and the load conditions which can be easily obtained when calculating, is easy to implement and has high practical value in engineering. BRIEF DESCRIPTION OF DRAWINGS

[0022] The above and other objects, features and advantages of the exemplary embodiments of the present application will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 A flowchart of a vertical stress calculation method 100 for a pile cap beam supported embankment according to an embodiment of the present application is schematically shown;

[0024] Figure 2 Basic physical parameter diagrams of various soil layers according to an embodiment of the present application are schematically shown;

[0025] Figure 3-1 A ground reinforcement scheme diagram according to an embodiment of the present application is schematically shown;

[0026] Figure 3-2 A pile arrangement design parameter diagram according to an embodiment of the present application is schematically shown;

[0027] Figure 3-3 An installation position diagram of a monitoring instrument of an engineering case according to an embodiment of the present application is schematically shown;

[0028] Figure 4-1 schematically illustrates a plan view of a pile cap beam structure composed of equilateral triangle piles according to an embodiment of the present application;

[0029] Figure 4-2 schematically illustrates a three-dimensional view of a pile cap beam structure composed of equilateral triangle piles according to an embodiment of the present application;

[0030] Figure 5-1 schematically illustrates a catenary arch model diagram according to an embodiment of the present application;

[0031] Figure 5-2 schematically illustrates a unit cell stress analysis diagram of a catenary arch model according to an embodiment of the present application;

[0032] Figure 6 schematically illustrates a flow chart of a critical height calculation method 600 for a pile cap beam supported embankment according to another embodiment of the present application;

[0033] Figure 7 schematically illustrates a soil stress distribution diagram at different depths when the fill height is 8m according to an embodiment of the present application;

[0034] In the drawings, identical or corresponding reference signs indicate identical or corresponding parts. DETAILED DESCRIPTION

[0035] The principles and spirits of the present application will be described below with reference to several exemplary embodiments. It should be understood that these embodiments are given only to enable those skilled in the art to better understand and implement the present application, and do not limit the scope of the present application in any way. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0036] According to an embodiment of the present application, a vertical stress and critical height calculation method for a pile cap beam supported embankment is proposed. Furthermore, any number of elements in the drawings is used for illustration and not limitation, and any naming is only used for differentiation and does not have any limiting meaning.

[0037] The principles and spirits of the present application will be described below with reference to several exemplary embodiments. It should be understood that these embodiments are given only to enable those skilled in the art to better understand and implement the present application, and do not limit the scope of the present application in any way. On the contrary, these embodiments are provided to make the present disclosure more thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art.

[0038] The present application combines the long-term stress deformation characteristics of the pile cap and beam test section, analyzes the mechanism of the beam structure for improving the bearing characteristics and anti-settlement deformation performance of the foundation, and then improves the existing friction arch model to be applicable to the triangular friction arch. The soil arch theory calculation method of the pile cap beam structure is modified, and the critical height calculation method is obtained through discussion and analysis.

[0039] After introducing the basic principles of the present application, the following will specifically introduce various non-limiting embodiments of the present application.

[0040] The following will describe a method for calculating vertical stress of a pile cap beam supported embankment according to an exemplary embodiment of the present application with reference to Figure 1 It should be noted that the embodiments of the present application can be applied to any applicable scenario, as long as it is in the application scenario involving calculating the soil arch vertical stress of a pile cap beam supported embankment, the method introduced in the present application can be used.

[0041] Figure 1 A flow chart of a method 100 for calculating vertical stress of a pile cap beam supported embankment according to an embodiment of the present application is schematically shown, which includes step S101 and step S102.

[0042] In step S101, the filling soil parameters, pile arrangement design parameters and subgrade top surface design load of the pile cap beam supported embankment are obtained.

[0043] The filling soil parameters of the pile cap beam supported embankment (hereinafter referred to as embankment filling soil parameters) include the cohesion c, internal friction angle and unit weight γ of each soil layer in the embankment. As an example, the embankment filling soil parameters can be determined by engineering site soil test. Standard soil test belongs to the prior art, for example, it can include in-situ shear and indoor direct shear test, etc., which will not be expanded here.

[0044] Figure 2 The parameters shown are the basic physical parameters of various soil layers obtained by engineering site soil test, from which the cohesion c, internal friction angle Figure 2 and other parameters of various soil layers can be obtained.

[0045] The pile arrangement design parameters include the pile arrangement mode, pile spacing D, pile cap radius r and ground beam width w, wherein the pile cap radius r can be directly measured, or the pile cap diameter R can be measured first, and then converted to obtain the pile cap radius r.

[0046] The pile arrangement mode in this embodiment is equilateral triangle (plum blossom type) pile arrangement (as shown in Figure 3-2 ), which contains three circular pile caps, the three circular pile caps are distributed in an equilateral triangle, and the pile caps are connected by ground beams.

[0047] In step S102, the vertical stress calculation formula is used to calculate the vertical stress of the pile cap beam supported embankment at a given depth according to the filling soil parameters, pile arrangement design parameters and subgrade top surface design load obtained in step S101.

[0048] ​The vertical stress calculation formula is the relationship between the vertical stress of the pile cap beam supported embankment and its fill parameters, pile layout design parameters, roadbed top surface design load and embankment depth.

[0049] In this embodiment, the vertical stress calculation formula is as follows:

[0050]

[0051] Where Z is the depth of the embankment, is the vertical stress of the pile cap beam supported embankment at depth Z, γ is the soil density, c, where is the cohesion and internal friction angle of the fill, respectively; K0 is the lateral pressure coefficient of the soil; and Q is the design load on the top surface of the roadbed. P is the vertical projection area of ​​the yield zone of the pile cap beam structure; and G is the perimeter of the yield zone of the pile cap beam structure.

[0052] in, , , D is the pile spacing, r is the pile cap radius, and w is the ground beam width.

[0053] The vertical stress calculation formula in this embodiment is obtained by Figure 4-1 and Figure 4-2 The pile cap beam structure (PCB structure for short) composed of equilateral triangular piles shown is obtained by stress analysis. Figure 4-1 This is a top view of the PCB structure. Figure 4-1 The area within the dotted line is defined as a unit, in which the soil directly above the pile cap and the ground beam is considered a rigid wall. Figure 4-1 If the soil within the range of the black thick solid line yields, the area within the black thick solid line is the yield area of ​​the PCB structure, the vertical projection area of ​​the yield area is P, and the perimeter is G. Figure 4-2 This is a three-dimensional view of the PCB structure. In order to facilitate stress analysis of the plastic zone, Figure 4-2 The rigid earth wall is not drawn. Figure 4-2 The total fill height of the middle embankment is h. A thin slice of soil with a thickness of dz is taken at a depth Z below the top of the fill. By performing a vertical force balance analysis on this thin slice of soil, the above vertical stress calculation formula can be obtained. This calculation formula can be used to calculate the vertical stress at any depth of the pile-cap-beam supported embankment.

[0054] In this embodiment, the calculation formula of the soil lateral pressure coefficient K0 is:

[0055]

[0056] Where, is the internal friction angle of fill.

[0057] The calculation formula of the lateral pressure coefficient K0 in this embodiment is obtained byFigure 5-1 The force balance analysis of a certain triangular microelement on the catenary arch wall surface is shown (see Figure 5-2 ), and is obtained by combining the Mohr circle and the lateral pressure coefficient definition. Figure 5-1 In the formula, the soil between the rigid walls is fully subsided, and the sliding surface reaches the plastic limit state, so that the wall is rough. According to the Mohr circle, the direction of the principal stress on the wall surface is deflected, and the angle of rotation is θ. θ is related to the roughness of the wall.

[0058] As other embodiments, the existing lateral pressure coefficient calculation formula can also be used to calculate the lateral pressure coefficient K0 of the soil.

[0059] In summary, by studying the load transfer mechanism of the pile cap beam structure, the vertical stress calculation method of the pile cap beam supported embankment at any depth under the condition of triangular pile arrangement and circular pile cap is obtained.

[0060] A critical height calculation method for a pile cap beam supported embankment according to an exemplary embodiment of the present application will be described below with reference to Figure 6 It should be noted that the embodiments of the present application can be applied to any applicable scenario as long as it is applied to the calculation of the critical height of the equal settlement surface (i.e. the height of the equal settlement surface to the top surface of the foundation) of the pile cap beam supported embankment.

[0061] Figure 6 A flowchart of a critical height calculation method 600 for a pile cap beam supported embankment according to an embodiment of the present application is schematically shown, which includes steps S601, S602 and S603.

[0062] In step S601, the filling soil parameters, pile arrangement design parameters, subgrade top surface design load and actual filling soil height of the pile cap beam supported embankment are obtained.

[0063] The method of obtaining the filling soil parameters, pile arrangement design parameters and subgrade top surface design load of the pile cap beam supported embankment in step S601 is the same as that in step S101, and will not be described here.

[0064] In step S602, the theoretical critical height of the equal settlement surface (i.e. the theoretical value of the critical height of the equal settlement surface) is calculated by using the critical height calculation formula according to the filling soil parameters, pile arrangement design parameters, subgrade top surface design load and actual filling soil height obtained in step S601.

[0065] The critical height calculation formula is a relationship formula between the critical height of the equal settlement surface of the pile cap beam supported embankment and its filling soil parameters, pile arrangement design parameters, subgrade top surface design load and actual filling soil height.

[0066] In this embodiment, the critical height calculation formula is:

[0067]

[0068] In the formula, h f is the theoretical critical height of the equal settlement surface, P is the area of the vertical projection of the yield region of the pile cap beam structure, G is the perimeter of the yield region of the pile cap beam structure, K0 is the lateral pressure coefficient of the soil, γ is the unit weight of the soil, c, and φ are the cohesion and internal friction angle of the fill respectively, Q is the design load on the top surface of the subgrade, and h is the actual fill height of the pile cap beam supported embankment. , D is the pile spacing, r is the pile cap radius, and w is the width of the ground beam.

[0069] The critical height calculation formula in this embodiment is obtained by stress analysis of the unit body in the formula. Figure 4-2 The critical height calculation formula of the present application shows that the critical height of the equal settlement surface is related to not only the fill parameters and pile arrangement design parameters of the pile cap beam supported embankment, but also the actual fill height h and the design load Q on the top surface of the subgrade.

[0070] In step S603, the theoretical critical height of the equal settlement surface is corrected in combination with the actual fill height of the pile cap beam supported embankment to obtain the actual critical height of the equal settlement surface.

[0071] Specifically, let h f be the theoretical critical height of the equal settlement surface, h be the actual fill height of the pile cap beam supported embankment, and h fc be the actual critical height of the equal settlement surface, then: when h f <h, h fc =h f ; and when h f >h, h fc =h.

[0072] In summary, the present application considers four factors in calculating the actual critical height of the equal settlement surface, which are: the fill parameters, the pile arrangement design parameters, the actual fill height, and the design load on the top surface of the subgrade of the pile cap beam supported embankment.

[0073] Therefore, the method of the present application has the following advantages:

[0074] (1) The present application additionally proposes the related elements for determining the critical height of the equal settlement surface of the pile cap beam supported embankment, i.e. it is proposed that the critical height of the equal settlement surface is not only related to the filling parameters of the embankment and the design parameters of the pile arrangement, but also positively related to the actual filling height of the embankment and the design load of the subgrade top surface. Compared with the existing calculation method of the critical height of the equal settlement surface which only considers the pile spacing or the net distance of the pile, the critical height of the equal settlement surface calculated by the present application is more accurate.

[0075] (2) Since the present application considers the influence of the actual filling height of the embankment when calculating the critical height of the equal settlement surface, compared with the existing calculation method which uses a fixed critical height, the problem that the theoretical value and the test value of the stress reduction rate of the subgrade top surface deviate greatly when the filling height of the embankment is high can be reduced.

[0076] (3) The present application only uses the embankment filling parameters, the design parameters of the pile arrangement, the filling height and the load conditions which can be easily obtained, and is easy to implement, and has high practical value in engineering.

[0077] The effectiveness of the method of the present application will be verified by specific application examples below.

[0078] In a specific application scenario, the filling type of a pile cap beam supported embankment is plain filling, and the basic physical parameters of the plain filling include: the unit weight of the plain filling is γ=17.6KN / m 3 , the cohesion is c=18kPa, and the internal friction angle is =12.8°. The ground reinforcement scheme of the pile cap beam supported embankment is shown in Figure 3-1 , from top to bottom: 1.8m plain filling, 11.6m silt, 14m silty clay, 5.2m sand, etc. Combined with Figure 3-2 , it can be obtained that the design parameters of the pile arrangement of the pile cap beam supported embankment are: equilateral triangle pile arrangement, the pile spacing D=4m, the pile cap diameter R=2m, and the beam width w=0.3m, and the pile cap radius r=1m can be calculated from the pile cap diameter R.

[0079] The internal friction angle =12.8° is substituted into the calculation formula of the lateral pressure coefficient K0, and the lateral pressure coefficient K0 can be obtained.

[0080] The critical height h f is: .

[0081] At this time: σ z =114kPa (Z=-5.9m).

[0082] The pile soil stress distribution diagram at different depths when the actual filling height h=8m is as shown in Figure 7The effectiveness of the method of the present application is verified by fitting the soil stress distribution at different depths between piles when the filling height h = 8m, as shown in the figure.

[0083] Those skilled in the art know that the embodiments of the present application can be implemented as a system, a method or a computer program product. Therefore, the present disclosure can be embodied in the form of entire hardware, entire software (including firmware, resident software, microcode, etc.), or a combination of hardware and software, which is generally referred to herein as "circuitry", "module", "unit" or "system". In addition, in some embodiments, the present application can also be implemented in the form of a computer program product in one or more computer readable media, which contains computer readable program code.

[0084] Any combination of one or more computer readable medium can be employed. The computer readable medium can be a computer readable signal medium or a computer readable storage medium. The computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any suitable combination of the above. More specific examples (non-exhaustive list) of the computer readable storage medium can include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the 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.

[0085] The computer readable signal medium can include a data signal propagated in a baseband or as a part of a carrier wave, in which computer readable program code is carried. Such propagated data signal can take various forms, including but not limited to electromagnetic signal, optical signal or any suitable combination of the above. The computer readable signal medium can also be any computer readable medium other than the computer readable storage medium, which can send, propagate or transmit a program for use by or in connection with an instruction execution system, apparatus or device. The program code contained on the computer readable medium can be transmitted by any suitable medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0086] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0087] The computer program instructions can 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 apparatus or other device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0088] The computer program instructions can 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 apparatus or other device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0089] It should be noted that, although several steps of the method for calculating the vertical stress and the critical height of a pile cap beam supported embankment are mentioned in the above detailed description, this division is not mandatory. Indeed, according to embodiments of the application, 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 into steps.

[0090] Further, although operations of the method of the present application are described in a particular order in the figures, this is not required or implied, nor is it necessary that all of the operations be performed to achieve desirable results. Rather, the order of the steps depicted in the flowcharts can be changed. Additionally or alternatively, certain steps can be omitted, combined into a single step, and / or broken into multiple steps.

[0091] The use of the verbs "including," "comprising," "comprises," and "comprising," along with their derivatives, are used herein to mean that the process, method, object, composition, or step includes, but is not limited to, those elements specifically named. The use of the articles "a" and "an" are used herein to mean one or more than one (i.e., "one or more"), unless otherwise indicated by the context of the words or phrases. The use of the term "about" accompanying an expression of value or dosage is intended to indicate that the value or dosage is approximate, and that minor variations are intended to be within the scope of the disclosure.

[0092] While the principles and spirit of the application have been described with reference to several specific embodiments, it is to be understood that the application is not limited to the specific embodiments disclosed, and that the division of aspects is not meant to imply that features from these aspects cannot be combined to benefit, but is merely for ease of presentation. The application 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 covers the entire scope of the expressions and encompasses all such modifications and equivalents.

Claims

1. A method for calculating the critical height of a pile cap beam supported embankment, characterized in that: include: Obtain fill parameters, pile layout design parameters, roadbed top surface design load, and actual fill height for pile cap beam supported embankments; The fill parameters include the cohesion, internal friction angle and density of each soil layer in the embankment; the pile layout design parameters include the pile layout method, pile spacing, pile cap radius and ground beam width; the pile layout method is an equilateral triangle pile layout; The theoretical critical height of the equal subsidence surface is calculated using the critical height calculation formula according to the fill parameters, pile layout design parameters, roadbed top surface design load and actual fill height; The critical height calculation formula is the relationship between the equal settlement surface critical height of the pile cap beam supported embankment and its fill parameters, pile layout design parameters, roadbed top surface design load and actual fill height; The theoretical critical height of the equal subsidence surface is corrected based on the actual fill height of the pile-cap-beam supported embankment to obtain the actual critical height of the equal subsidence surface.

2. The critical height calculation method for pile cap beam supported embankment according to claim 1, characterized in that: The critical height calculation formula is: ； Where h f is the theoretical critical height of the equal sinking surface, P is the vertical projection area of ​​the pile cap beam structure yield area, G is the perimeter of the pile cap beam structure yield area, K0 is the lateral pressure coefficient of the soil, γ is the specific gravity of the soil, c, are the cohesion and internal friction angle of the fill, Q is the design load on the top surface of the roadbed, and h is the actual fill height of the pile cap beam supported embankment.

3. The critical height calculation method for pile cap beam supported embankment according to claim 2, characterized in that: The method of correcting the theoretical critical height of the equal subsidence surface based on the actual fill height of the pile cap beam supported embankment includes: If the theoretical critical height of the equal subsidence surface is less than the actual fill height, the actual critical height of the equal subsidence surface is equal to the theoretical critical height of the equal subsidence surface; If the theoretical critical height of the equal subsidence surface is greater than the actual fill height, the actual critical height of the equal subsidence surface is equal to the actual fill height.

4. The critical height calculation method for pile cap beam supported embankment according to claim 3, characterized in that: The lateral pressure coefficient K0 of soil is: .

5. The critical height calculation method for pile cap beam supported embankment according to claim 4, characterized in that: The vertical projection area P of the yielding region of the pile cap beam structure is: , the perimeter G of the yielding area of ​​the pile cap beam structure is: , where D is the pile spacing, r is the pile cap radius, and w is the ground beam width.

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