Calculation method for horizontal stress and deformation of permanent and temporary combined pile foundation structure of hub

Abstract

The invention discloses a calculation method for horizontal stress and deformation of a permanent and temporary combined pile foundation structure of a hub. The calculation method comprises the following steps: simplifying a row of piles into a plane rigid frame structure consisting of vertically arranged elastic foundation beams; determining pile periphery stratum parameters and enclosure structure design parameters; calculating the spring stiffness of strata on the sides of the front and rear row piles and between the row piles; calculating an equivalent line load standard value acting on the rear-row pile; establishing a load-structure model, inputting boundary parameters, and performing numerical analysis and calculation; and reading the internal force value and the deformation value of the pile body under the action of the horizontal force. According to the method, the multiple rows of piles are simplified into a plane rigid frame structure composed of the vertically-arranged elastic foundation beams, solving of the internal force and deformation of the pile foundation structure under the action of horizontal force is achieved, and the problem that calculation of three rows of piles or multiple rows of piles is still blank in the existing Technical Regulations for Foundation Pit Supporting (JGJ120) is solved. And each foundation pit project can be better combined with the actual condition of the project to carry out refined and rapid design on the permanent and temporary combined pile foundation structure.

Description

Technical Field

[0001] This invention belongs to the technical field of foundation excavation design, and in particular, it is a method for calculating the horizontal stress and deformation of a combined permanent and temporary pile foundation structure for a hub. Background Technology

[0002] In recent years, with the rapid development of China's social economy, integrated transportation hubs centered on projects such as airports, rail transit, and highways have developed rapidly. The design of integrated transportation hubs requires comprehensive consideration of numerous buildings and structures within these projects. Due to the deep integration of functions within integrated transportation hubs, the retaining piles of underground works and the foundation piles of above-ground works often have very close proximity or even conflict. In this context, the combined permanent and temporary pile foundation structure, with its advantages of flexible solutions, low cost, and short construction period, has become the key to solving this problem.

[0003] By encompassing the layout, pile diameter, pile spacing, and pile length of permanent pile foundations for above-ground engineering and temporary retaining piles for underground engineering, a combined permanent and temporary pile foundation design scheme that also serves as temporary retaining function can be formed. However, the current "Technical Specification for Foundation Pit Support" (JGJ120) only discusses the calculation of double-row piles, and the calculation of triple-row or multi-row piles is still lacking.

[0004] Establishing a stress calculation model for three or more rows of piles, considering the ground pressure at the bottom of the pit and on the back of the pile, and the resistance of the ground to the pile body are major challenges in the refined and rapid design of permanent and temporary pile foundations in large-scale integrated transportation hub projects. Summary of the Invention

[0005] In response to the problems raised above, this invention proposes a method for calculating the horizontal stress and deformation of a combined permanent and temporary pile foundation structure, the specific scheme of which is as follows: A method for calculating the horizontal stress and deformation of a combined permanent and temporary pile foundation structure, comprising pile rows, the calculation method including the following steps: Step S1: Based on the load-structure method calculation theory, the pile wall is simplified into a planar rigid frame structure; Based on the load-structure method calculation theory, the pile row is simplified into a planar rigid frame structure composed of vertically set elastic foundation beams. The planar rigid frame structure includes a front row of piles, a middle row of piles, a rear row of piles, a pile cap, a ground spring in the embedded section of the front row of piles, a ground spring between piles, a ground spring on the side of the rear row of piles, vertical constraint at the pile bottom, a base and ground line, and connecting beams. The connecting beam connects the tops of the front row of piles, the middle row of piles, and the rear row of piles, and the bottoms of the front row of piles, the middle row of piles, and the rear row of piles are respectively connected to vertical constraints; Inter-pile ground springs are provided between the front row of piles and the middle row of piles, and between the middle row of piles and the rear row of piles; The pile cap and the connecting beam are intersecting and connected as a whole along the length of the foundation pit, and the bottom of the pile cap and the connecting beam are on the same horizontal line as the ground line; The front row of piles is provided with a ground spring in the embedded section of the front row of piles on the side close to the base line, and the rear row of piles is provided with a ground spring on the side of the piles on the side close to the ground line. Step S2: Determine the soil parameters around the piles and the design parameters of the retaining structure; Determine the soil parameters around the piles and the design parameters of the retaining structure based on the project's engineering geological survey report and foundation pit design plan; Step S3: Calculate the spring stiffness of the ground strata on the sides of the front and rear rows of piles and between the piles; The spring stiffness of the stratum in the front row of pile embedment section ; Among them, subscript i Representing the i Each stratum, The horizontal reaction force coefficient of the formation is taken as a value of , m The proportionality coefficient of the formation horizontal reaction force coefficient, with a value of [value missing]. , The value is the horizontal displacement of the retaining member at the bottom of the pit. , z To calculate the depth of the point, To calculate the height, the length of the pile element in the model is taken; The spring stiffness of the pile-inter-piles stratum ; in The horizontal stiffness coefficient of the soil between piles is taken as a value. ; The stiffness of the ground spring on the side of the rear piles ; Step S4: Calculate the standard value of the equivalent line load acting on the rear pile 3; Calculate the standard value of the equivalent line load of the rear piles under the combined action of ground pressure and additional load at the top of the pit: ,in This is the standard value of active pressure intensity in the formation, and it is taken as [value]. , The standard value of vertical stress in the formation is given by a value of [value to be filled in]. , The total vertical stress generated by the soil's self-weight at the calculation point on the outside of the retaining structure is given. Let be the standard value of the additional vertical stress in the soil at the calculation point under the j-th additional load on the outer side of the retaining structure. For the uniformly distributed load, take the value as... , The standard value of the uniformly distributed additional load. Let be the active earth pressure coefficient of the i-th soil layer, and take a value of . ; Step S5: Establish a load-structure model, input boundary parameters, and perform numerical analysis calculations; A simplified load-structure model is established using relevant structural calculation and analysis software. Then, the boundary parameters calculated in the above steps are used to set the model boundary conditions and load values. Step S6: Read the internal force and deformation values ​​of the pile body under the action of horizontal force.

[0006] Run the calculation model to read the standard values ​​of bending moment and shear force of the pile body under horizontal force, as well as the lateral deformation value, for verification related to pile foundation structure design.

[0007] Preferably, in step S1, when the geological conditions are good, the calculation method can be simplified, the vertical displacement of the pile foundation structure can be ignored, and the vertical constraint can be set at the bottom of the pile.

[0008] Preferably, in step S2, the soil parameters around the pile include the unit weight of each soil layer. Cohesion internal friction angle Compression modulus and horizontal bed coefficient Parameters, the retaining structure parameters include the pile diameter. d Pile length l Foundation pit depth h Pile spacing Distance from pile row parameter.

[0009] Preferably, in steps S3 and S4, since the load near the pile bottom of the permanent-temporary combined pile foundation estimated by the active earth pressure coefficient is too small during the temporary use period, in order to make the results more accurate, a ground spring is added to the side of the pile of the rear row of piles.

[0010] Preferably, in step S4, since the stratum does not exert tensile force on the pile foundation structure, the calculated standard value of the active earth pressure strength of the stratum... At that time, take .

[0011] Preferably, in step S5, to simplify the calculation, the length of each pile body unit in the planar rigid frame model established based on the retaining structure type can be taken as 1m.

[0012] Preferably, in step S6, the pile bending moment and shear force calculated by this model are standard values. The standard values ​​are multiplied by partial factors to obtain the design values, and then the relevant verification calculations for pile foundation structure design are performed.

[0013] Preferably, the calculation method is applicable to retaining structures with single-row or multi-row piles, and is applicable to retaining structures with arbitrary combinations of different pile diameters, different pile lengths, different pile spacings, and different concrete grades among multiple rows of piles.

[0014] The beneficial effects of this invention are: This invention proposes a calculation method for the horizontal stress and deformation of a combined permanent and temporary pile foundation structure. It creatively simplifies the pile row into a planar rigid frame structure composed of vertically arranged elastic foundation beams. By establishing a load-structure model, the internal forces and deformations of the pile foundation structure are solved. This fills the gap in the current "Technical Specification for Foundation Pit Support" (JGJ120) regarding the calculation of three or more rows of piles, and solves the problems existing in the calculation of combined permanent and temporary pile foundations during the temporary use stage. It achieves the goal of more refined and rapid design of combined permanent and temporary pile foundations under similar working conditions, and can more fully consider the role of combined permanent and temporary pile foundations during foundation pit excavation, making the design scheme more reasonable and economical, and the design process simpler and faster. Attached Figure Description

[0015] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless specifically indicated, these drawings are intended only to conceptually illustrate the structural construction described herein and are not necessarily drawn to scale.

[0016] Figure 1 This is a flowchart of the calculation method provided in this invention; Figure 2 This is a simplified calculation diagram of the multi-row pile structure in this invention; Figure 3 This is the foundation pit plan view of Application Example 1 in this invention; Figure 4 This is the cross-sectional view of the foundation pit and the established calculation model in Application Example 1 of this invention; Figure 5 This is the bending moment and shear force diagram calculated using this method in Application Example 1 of this invention; Figure 6 This is the deformation diagram calculated using this method in Application Example 1 of this invention; Figure 7 This is the internal force and deformation diagram calculated using the Morning Star method in Application Example 1 of this invention; Figure 8 This is the foundation pit plan view of Application Example 2 in this invention; Figure 9 This is the cross-sectional view of the foundation pit and the established calculation model in Application Example 2 of this invention; Figure 10 This is the bending moment and shear force diagram calculated using this method in Application Example 2 of this invention; Figure 11 This is the deformation diagram calculated using this method in Application Example 2 of this invention; In the picture: 1-Front row of piles; 2-Middle row of piles; 3-Rear row of piles; 4-Pile foundation cap; 5-Soil spring in the embedded section of the front row of piles; 6-Soil spring between piles; 7-Soil spring on the side of the rear row of piles; 8-Vertical constraint; 9-Base line; 10-Ground line; 11-Connecting beam. Detailed Implementation

[0017] First, it should be noted that the specific structure, features, and advantages of the present invention will be described in detail below by way of examples. However, all descriptions are for illustrative purposes only and should not be construed as limiting the present invention in any way. Furthermore, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature shown or implied in the accompanying drawings, can still be arbitrarily combined or deleted among these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein. Additionally, for the sake of simplifying the drawings, the same or similar technical features may be indicated only in one place in the same drawing.

[0018] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0019] The following is in conjunction with the appendix Figure 1-11 This invention will be described in detail.

[0020] Example 1: A method for calculating the horizontal stress and deformation of a combined permanent and temporary pile foundation structure, comprising pile rows, the calculation method including the following steps: Step S1: Based on the load-structure method calculation theory, the pile wall is simplified into a planar rigid frame structure; Based on the load-structure method calculation theory, the pile row is simplified into a planar rigid frame structure composed of vertically set elastic foundation beams. The planar rigid frame structure includes a front pile row 1, a middle pile row 2, a rear pile row 3, a pile foundation cap 4, a ground spring in the embedded section of the front pile row 5, a ground spring between piles 6, a ground spring on the side of the rear pile row 7, a vertical constraint at the pile bottom 8, a base line 9 and a ground line 10, and a connecting beam 11. The connecting beam 11 connects the tops of the front row of piles 1, the middle row of piles 2 and the rear row of piles 3, and the bottoms of the front row of piles 1, the middle row of piles 2 and the rear row of piles 3 are respectively connected to vertical constraints 8; A pile-to-soil spring 6 is provided between the front row of piles 1 and the middle row of piles 2, and between the middle row of piles 2 and the rear row of piles 3; The pile cap 4 and the connecting beam 11 are intersected and connected as a whole in the length direction of the foundation pit. The bottom of the pile cap 4 and the connecting beam 11 are on the same horizontal line as the ground line 10. The front row of piles 1 is provided with a ground spring 5 for the embedded section of the front row of piles 1 near the base line 9, and the rear row of piles 3 is provided with a ground spring 7 for the pile side of the rear row of piles 3 near the ground line 10. Step S2: Determine the soil parameters around the piles and the design parameters of the retaining structure; Determine the soil parameters around the piles and the design parameters of the retaining structure based on the project's engineering geological survey report and foundation pit design plan; Step S3: Calculate the spring stiffness of the ground strata on the sides of the front and rear rows of piles and between the piles; The ground spring stiffness of the front row of piles is 5. ; Among them, subscript i Representing the i Each stratum, The horizontal reaction force coefficient of the formation is taken as a value of , m The proportionality coefficient of the formation horizontal reaction force coefficient, with a value of [value missing]. , The value is the horizontal displacement of the retaining member at the bottom of the pit. , z To calculate the depth of the point, To calculate the height, the length of the pile element in the model is taken; The ground spring between the piles has a stiffness of 6. ; in The horizontal stiffness coefficient of the soil between piles is taken as a value. ; The stiffness of the ground spring 7 on the side of the rear piles ; Step S4: Calculate the standard value of the equivalent line load acting on the rear pile 3; Calculate the standard value of the equivalent line load of the rear piles under the combined action of ground pressure and additional load at the top of the pit: ,in This is the standard value of active pressure intensity in the formation, and it is taken as [value]. , The standard value of vertical stress in the formation is given by a value of [value to be filled in]. , The total vertical stress generated by the soil's self-weight at the calculation point on the outside of the retaining structure is given. Let be the standard value of the additional vertical stress in the soil at the calculation point under the j-th additional load on the outer side of the retaining structure. For the uniformly distributed load, take the value as... , The standard value of the uniformly distributed additional load. Let be the active earth pressure coefficient of the i-th soil layer, and take a value of . ; Step S5: Establish a load-structure model, input boundary parameters, and perform numerical analysis calculations; A simplified load-structure model is established using relevant structural calculation and analysis software. Then, the boundary parameters calculated in the above steps are used to set the model boundary conditions and load values. Step S6: Read the internal force and deformation values ​​of the pile body under the action of horizontal force.

[0021] Run the calculation model to read the standard values ​​of bending moment and shear force of the pile body under horizontal force, as well as the lateral deformation value, for verification related to pile foundation structure design.

[0022] Among them, the connecting beam 11 can also be a connecting plate.

[0023] Furthermore, in the embodiments, it can be considered that in step S1, when the geological conditions are good, the calculation method can be simplified, the vertical displacement of the pile foundation structure can be ignored, and the vertical constraint 8 can be set at the bottom of the pile.

[0024] Furthermore, in the embodiments, it can be considered that in step S2, the soil parameters around the pile include the unit weight of each soil layer. Cohesion internal friction angle Compression modulus and horizontal bed coefficient Parameters, the retaining structure parameters include the pile diameter. d Pile length l Foundation pit depth h Pile spacing Distance from pile row parameter.

[0025] Furthermore, in the embodiments, it can also be considered that in steps S3 and S4, since the load near the pile bottom of the permanent-temporary combined pile foundation estimated by the active earth pressure coefficient is too small during the temporary use, in order to make the results more accurate, a pile side spring 7 of the rear row of piles is added to the outside of the structure.

[0026] Furthermore, in the embodiments, it can be considered that in step S4, since the stratum does not exert tensile force on the pile foundation structure, the calculated standard value of the active earth pressure strength of the stratum... At that time, take .

[0027] Furthermore, in the embodiments, it can be considered that, in step S5, to simplify the calculation, the length of each row of piles in the planar rigid frame model established according to the retaining structure type can be taken as 1m.

[0028] Furthermore, in the embodiments, it can also be considered that in step S6, the pile bending moment and shear force calculated by this model are standard values, and the standard values ​​are multiplied by partial factors to obtain the design values, and then the relevant verification calculations for pile foundation structure design are performed.

[0029] Furthermore, in the embodiments, the calculation method can be considered to be applicable to retaining structures with single-row or multi-row piles, and applicable to retaining structures with arbitrary combinations of different pile diameters, different pile lengths, different pile spacings, and different concrete grades among multiple rows of piles.

[0030] This calculation method is applicable not only to retaining structures with single-row, double-row, triple-row, and even multi-row piles, but also to retaining structures with different pile diameters, lengths, spacings, and concrete grades among multiple rows of piles. It can be used to refine the design based on the actual conditions of the project as much as possible.

[0031] Application Example 1: The following description applies the calculation method based on Example 1.

[0032] Taking the foundation pit project of a rail transit and airport integrated transportation hub as an example, the calculation is performed. The foundation pit layout plan is as follows: Figure 3 As shown, a row of airport pile foundation caps 4 is located adjacent to the outer side of the rail transit foundation pit. These airport pile foundation caps 4 are 6-pile caps; the piles filled in the shaded area are permanent-temporary combined pile foundations, while the unfilled piles are temporary retaining piles. The pile foundation caps 4 and the retaining plate are spaced apart. The cross-section of the foundation pit retaining structure is shown below. Figure 4 As shown, the depth of the rail transit foundation pit is 12m, the length of the front and rear rows of piles is 20m each, the length of the pile bottom embedded section is 8m, the concrete strength grade is C30, and other relevant parameters are as follows: 1. Formation parameters: There are four strata within the length of the permanent and temporary combined piles, including silty clay and mudstone layers with different degrees of weathering. The basic parameters of each stratum are as follows: Number of strata: 4; Stratum thickness: 2m, 2m, 6m, 10m; strata density γ i 20.1 kN / m 3 19.4 kN / m 3 22kN / m 3 24kN / m3 ; Formation cohesion c i :22.33kPa, 37.33kPa, 0kPa, 0kPa; Internal friction angle of formation φ i : 18.1°, 21.3°, 38°, 40°; Formation compressibility modulus E si : 6.5MPa, 15MPa, 65.522MPa, 187.435MPa; Horizontal subgrade coefficient k hi : 23MPa / m, 35MPa / m, 80MPa / m, 105MPa / m; According to the formula Determine the stratigraphy m Value: 6.975 MPa / m 2 10.677 MPa / m 2 25.08 MPa / m 2 28MPa / m 2 ; According to the formula Calculate the active earth pressure coefficient of the formation Values: 0.52593, 0.46708, 0.23788, 0.21744.

[0033] 2. Envelope design parameters: Excavation depth: h =12m; Length of retaining piles: l =20m; Retaining pile diameter: d =1.2m; Spacing of retaining piles: b a =1.6m; Spacing of retaining piles: s y =3.2m.

[0034] 3. The spring stiffness and ground reaction force (boundary parameters) borne by the pile foundation are calculated based on the foundation parameters as follows: Stiffness of the ground spring in the front row of pile embedded section: according to the formula The horizontal reaction force coefficient of the stratum in the embedded section of the first row of piles was obtained. Then the spring stiffness is obtained as ; Stiffness of the ground spring between piles: According to the formula Calculate the horizontal stiffness coefficient of the soil between piles Then, the stiffness of the spring in the soil between the piles was obtained. That is, each stratum Kc The values ​​are 5.2 MN / m, 12 MN / m, 52.4176 MN / m, and 149.948 MN / m, respectively; Stiffness of the ground spring on the side of the rear pile: according to the formula The spring stiffness values ​​of the three strata of the rear piles were found to be 36.8MN / m, 56MN / m, 128MN / m, and 168MN / m, respectively. The rear piles bear the pressure line loads of various strata according to the formula: The standard values ​​of active earth pressure intensity for each stratum were obtained: for the first two strata, the values ​​were 0. kPa Top of the third stratum ,bottom Top of the fourth stratum ,bottom Then, the pressure line loads of the strata under each of the three rear piles were obtained. For: the first two strata Top of the third stratum ,bottom Top of the fourth stratum ,bottom .

[0035] 4. Structural calculations: A simplified load-structure model of a double-row pile planar rigid frame was established using Midas Gen software to perform structural stress and deformation calculations and analyses. Figure 4 As shown, by inputting the corresponding boundary parameters, the horizontal bending moment, shear force, and horizontal displacement of the retaining pile are calculated. Figures 5-6 As shown, the double-row pile structure was also verified and analyzed using the commonly used foundation pit design software Qimingxing FRWS 9.0. The calculated results of internal forces and deformations are as follows. Figure 7 As shown in the figure. Comparing the results obtained from the two calculation methods, it can be found that the results of pile internal force and deformation are almost completely consistent. The maximum lateral displacement of the pile top calculated by FRWS 9.0 is 25.2 mm, while the maximum lateral displacement of the pile top calculated by this method is 25.86 mm, with an error of only 2.55%. The maximum bending moment of the first pile in the front row calculated by FRWS 9.0 is 1032.4 kNm, while the maximum bending moment of the first pile in the front row calculated by this method is 987.0 kNm, with an error of only 4.4%. The maximum bending moment of the third pile in the rear row calculated by FRWS 9.0 is 661.6 kNm, while the maximum bending moment of the third pile in the rear row calculated by this method is 656.6 kNm, with an error of only 0.76%. It can be seen that the calculation method can ensure high calculation accuracy and meet the needs of construction drawing design in specific projects.

[0036] Application Example 2: Taking another area of ​​the same integrated transportation hub foundation pit project as an example, the foundation pit layout plan is as follows: Figure 8 As shown, a row of airport 9-pile pile caps 4 are located adjacent to the outer side of the rail transit foundation pit. The piles filled in the shade are permanent-temporary combined piles, while the unfilled piles are temporary retaining piles. The pile caps 4 and the retaining structure connection plates are spaced apart. The cross-section of the foundation pit retaining structure is shown below. Figure 9 As shown, the depth of the rail transit foundation pit is 12m, the length of the three piles in the front, middle and rear rows is 20m, the length of the embedded section at the bottom of the pile is 8m, and the concrete strength grade is C30. The relevant parameters used in this embodiment, including the stratum parameters, retaining structure parameters and boundary parameters input to the calculation model, are the same as those in Application Example 1.

[0037] Similarly, using Midas Gen software, a simplified load-structure model of a three-row pile planar rigid frame is established to perform structural stress and deformation calculations and analyses. By inputting the corresponding boundary parameters, the horizontal bending moment, shear force, and horizontal displacement of the retaining piles are calculated. Figures 10-11 As shown, after considering the horizontal force of the third row of piles, the maximum lateral displacement of the pile top is 22.2 mm, which is 14.2% less than that of the double-row piles; the maximum bending moment of the first pile of the front row is 806.0 kNm, which is 18.3% less than that of the double-row piles; and the maximum bending moment of the last two rows of piles is 601.5 kNm, which is 8.4% less than that of the double-row piles.

[0038] In summary, this calculation method can accurately calculate the lateral displacement of the permanent-temporary combined pile foundation during the foundation pit excavation stage. This is crucial for the subsequent verification of the permanent-temporary combined pile foundation during the permanent service stage. At the same time, this calculation method can be used to optimize the design parameters of the permanent-temporary combined pile foundation during the foundation pit excavation stage.

[0039] The above embodiments and application examples have provided a detailed description of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered as limiting the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the patent coverage of the present invention.

Claims

1. A method for calculating the horizontal stress and deformation of a hinge permanent- temporary combined pile foundation structure, characterized in that: The calculation method comprises the following steps: Step S1: simplifying the row piles into a plane rigid frame structure based on load-structure calculation theory; Step S2: determining the parameters of the stratum around the piles and the design parameters of the enclosure structure; Step S3: calculating the stiffness of the stratum spring on the sides of the front and rear row piles and between the row piles; Step S4: calculating the equivalent line load standard value acting on the rear row piles (3); Step S5: establishing a load-structure model, inputting boundary parameters, and performing numerical analysis calculation; Step S6: reading the internal force value and deformation value of the pile body under the action of horizontal force; In the step S1, when the geological condition is good, the calculation method can be simplified, and the vertical constraint (8) is set at the bottom of the pile, ignoring the displacement of the pile foundation structure in the vertical direction. In the steps S3 and S4, since the active soil pressure coefficient is used to estimate the load near the bottom of the pile during the temporary use of the permanent and temporary combined pile foundation, the result is smaller, and therefore, the rear row pile stratum spring (7) is added outside the structure to make the result more accurate. In the step S5, for the purpose of simplifying the calculation, the length of the pile body unit of each row pile in the plane rigid frame model established according to the type of the enclosure structure can be taken as 1 m. The front row pile embedded segment stratum spring (5) stiffness ; wherein the subscript i represents the i th stratum, is the horizontal reaction force coefficient of the stratum, and has a value of , m is a proportional coefficient of the horizontal reaction force coefficient of the stratum, and has a value of , is the horizontal displacement amount of the retaining member at the pit bottom, and has a value of , z is the depth of the calculation point, is the calculation height, and is the length of the pile element divided by the model. The inter-pile ground spring (6) stiffness ; wherein is the horizontal stiffness coefficient of the ground between the piles, which is taken as ; The rear row pile side stratum spring (7) stiffness ; In the step S6, the bending moment and shear force of the pile body calculated by the model are standard values, and the design value is obtained by multiplying the standard value by the partial coefficient, and then the relevant checking calculation for the pile foundation structure design is performed. The equivalent line load standard value of the post-row pile under the combined action of the stratum pressure and the additional load on the pit top is calculated: wherein is the active pressure intensity standard value of the stratum, and is taken as , is the vertical stress standard value of the stratum, and is taken as , is the total vertical stress of the calculation point on the outer side of the enclosure structure generated by the self weight of the soil, is the additional vertical stress standard value of the calculation point in the soil under the action of the jth additional load on the outer side of the enclosure structure, and is taken as , is the uniform additional load standard value, is the active earth pressure coefficient of the ith layer of soil, and is taken as ; ​ ​ ​ ​ 2. The method for calculating the horizontal stress and deformation of a hinge permanent- temporary combined pile foundation structure according to claim 1, characterized in that: ​ 3. The method of claim 1, wherein the method is characterized by: The pile-surrounding stratum parameters include respective stratum specific gravities , cohesion forces , internal friction angles , compression moduli , and horizontal base coefficients , and the enclosure parameters include pile diameters d , pile lengths l , pit depths h , pile spacings , and pile row spacings .

4. The method of claim 1, wherein the method is characterized by: ​ 5. The method of claim 1, wherein: In the step S4, since the stratum will not generate tensile force to the pile foundation structure, when the calculated standard value of the stratum active earth pressure intensity is , the following is taken .

6. The method of claim 1, wherein: ​ 7. The method of claim 1, wherein the method is characterized by: ​ 8. The method for calculating the horizontal stress and deformation of a permanent- temporary combined pile foundation structure according to any one of claims 1-7, characterized in that: The calculation method is suitable for the enclosure structure of single-row piles or multi-row piles, and is suitable for the enclosure structure of any combination of different pile diameters, different pile lengths, different pile spacings and different concrete grades between the multi-row piles.

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