Calculation method and device for deformation of anchored double-row pile support structure in rock-soil combined strata

Abstract

The present invention discloses a deformation calculation method and device for anchored double-row pile support structure in rock-soil combination strata, including: determining the position of the sliding surface of the support structure; obtaining the differential equations of the deflection of the front and rear row piles above the sliding surface; obtaining the differential equations of the deflection of the front and rear row piles below the sliding surface; determining the different soil resistance distribution functions of the front and rear row piles in the rock-soil combination strata; using the segmented independent coordinate method based on the synergy of piles and anchors to segment the front and rear row piles; and calculating the deformation of the pile body according to the differential equations of each segment. The technical solution of the present invention can more accurately calculate the stress deformation of the anchored double-row pile support structure in the rock-soil combination strata, especially the stress deformation of the rear row piles.

Description

Technical Field

[0001] The invention belongs to the technical field of geotechnical engineering, and specifically relates to a method and device for calculating the deformation of a geotechnical composite stratum anchored double-row pile support structure taking into account different geotechnical resistances of front and rear row piles. Background Art

[0002] Among various supporting structures of deep foundation pits, the composite supporting structure with anchored double-row piles is widely used in foundation pit projects due to its excellent ability to control deformation. The stress deformation of the retaining structure is the top priority of the safety and stability analysis of deep foundation pits, and it is also the focus of attention in the design process of deep foundation pits. At present, for the calculation method of the internal force deformation of the anchored double-row pile supporting structure system, in order to facilitate the calculation, most of them regard the compression modulus of the soil between the piles as a constant to calculate the soil resistance. However, in actual engineering, the compression modulus, especially under the geological conditions of rock-soil combined strata, can no longer be regarded as the same value for the geotechnical resistance modulus of the front and rear rows of piles, but should be discussed in sections and categories. On the other hand, most of the current calculation methods regard the anchor cable as a horizontal spring support without considering the short-term prestress loss when the anchor cable is locked, and even less considering the different prestress loss rates of the anchor cable in the rock and soil layer. The above drawbacks are bound to cause a large deviation from the actual situation, which will cause safety hazards to the design and guidance of foundation pit projects. Summary of the invention

[0003] In order to reduce the above-mentioned calculation errors and make the calculation results closer to the actual situation, the present invention proposes a calculation method and device for the deformation of an anchored double-row pile support structure in a rock-soil combination stratum taking into account the different rock and soil resistance of the front and rear rows of piles, which can more accurately calculate the stress deformation of the anchored double-row pile support structure, especially the stress deformation of the rear row of piles.

[0004] To achieve the above object, the present invention adopts the following technical solution:

[0005] A method for calculating the deformation of a rock-soil combined stratum anchored double-row pile support structure comprises the following steps:

[0006] Determine the position of the sliding surface of the supporting structure;

[0007] According to the position of the sliding surface of the supporting structure, the differential equation of the pile body deflection of the front and rear rows of piles above the sliding surface is obtained;

[0008] According to the position of the sliding surface of the supporting structure, the differential equation of the pile body deflection of the front and rear rows of piles below the sliding surface is obtained;

[0009] Determine the different soil resistance distribution functions of the front and rear rows of piles in the rock-soil composite strata.

[0010] The piles in the front and rear rows are divided into sections by adopting the segmented independent coordinate method based on the synergistic effect of piles and anchors. The differential equations of the sections of the piles in the front and rear rows are obtained according to the different soil resistance distribution functions of the front and rear rows in the rock-soil composite strata, the differential equations of the deflection of the piles in the front and rear rows above the slip surface, and the differential equations of the deflection of the piles in the front and rear rows below the slip surface.

[0011] The pile deformation is calculated according to the differential equations of each segment.

[0012] As a preferred method, the shear sliding surface is assumed to start from the base of the front row of piles, and the angle between the sliding surface and the vertical direction is The position equation of the sliding surface of the supporting structure is:

[0013]

[0014] Among them, L 0 It represents the distance from the top of the front pile when the sliding surface extends to the ground, α represents the earth pressure distribution coefficient, represents the internal friction angle of soil, L 0 It indicates the distance from the top of the front row of piles when the sliding surface extends to the ground, and L indicates the distance between the front and rear rows of piles.

[0015] As a preferred embodiment, the differential equation for the deflection of the front and rear row piles above the sliding surface is:

[0016] Front pile:

[0017] Back pile:

[0018] Among them, q bi represents the overall soil pressure distribution behind the piles above the shear slip surface of the front row piles, q ai represents the overall soil pressure distribution behind the piles above the shear slip surface of the rear piles; EI represents the bending stiffness of the pile body, y bi represents the displacement of the i-th pile in the front row, y ai represents the displacement of the i-th pile in the rear row, z bi represents the length of the i-th section of the front row of piles, z ai Represents the length of the i-th section of the rear row of piles.

[0019] As a preferred embodiment, the differential equation for the deflection of the front and rear row piles below the sliding surface is:

[0020] Front pile:

[0021] Back pile:

[0022] Among them, P b It represents the overall earth pressure on the supporting structure below the sliding surface of the front row piles, P arepresents the overall earth pressure on the supporting structure below the sliding surface of the rear piles, p b (y,z) and p a (y,z) represent the different foundation reaction functions of the front and rear rows of piles in the rock and soil strata respectively.

[0023] As a preferred method, the resistance functions and values ​​of the front and rear rows of piles in the rock-soil composite stratum are:

[0024] Front pile:

[0025] Back pile:

[0026] Where z≤h s Represents soil layer, z>h s Time represents rock layer, E s is the compression modulus of soil between piles, m r Represents the horizontal resistance coefficient of soil in the rock layer, m s Indicates the horizontal resistance coefficient of soil in the rock layer; z a Indicates the length of the rear pile, z b Indicates the length of the front row of piles; b 0 Indicates the calculated width of the pile; y b represents the displacement of the front pile, y a Indicates the displacement of the rear pile; s y represents the distance between double-row piles, d represents the pile diameter; h represents the distance between double-row piles, d represents the pile diameter; s Represents the depth of soil, and n is the exponent of the power series function.

[0027] Preferably, according to the piecewise independent coordinate method, if the anchored double-row piles have x anchor cables, the pile bodies of the front and rear rows of piles above the slip surface can be divided into x+2 pile unit bodies, and x+2 piecewise deflection differential equation groups are listed respectively according to the deflection differential equations of the front and rear rows of piles above the slip surface.

[0028] As a preferred embodiment, when there are rock layers and soil layers below the sliding surface, the pile bodies of the front and rear rows of piles are divided into four sections. According to the differential equation of the deflection of the pile bodies of the front and rear rows of piles below the sliding surface,

[0029] The deflection equation of the pile in soil is:

[0030] Front pile:

[0031] Back pile:

[0032] The differential equation for pile deflection in rock formation is:

[0033] Front pile:

[0034] Back pile:

[0035] Among them, P bs P represents the overall load on the pile side in the soil layer below the sliding surface of the front pile. as It represents the overall load on the pile side in the soil layer below the sliding surface of the rear pile, P br It represents the overall load on the pile side in the rock layer below the sliding surface of the front pile, P ar The overall load on the pile side in the rock layer below the sliding surface of the rear pile is shown in E s is the compression modulus of soil between piles, y bs represents the horizontal displacement of the front row piles in the soil layer below the sliding surface, y as represents the horizontal displacement of the rear row pile in the soil layer below the sliding surface; br represents the horizontal displacement of the front row piles in the rock layer below the slip surface, y ar Indicates the horizontal displacement of the rear row piles in the rock layer below the slip surface; br represents the length of the front row of piles in the rock layer below the sliding surface, z ar Indicates the length of the rear row of piles in the rock layer below the slip surface; z bs represents the length of the front row of piles in the soil layer below the sliding surface, z as Indicates the length of the rear row of piles in the soil layer below the sliding surface.

[0036] As a preferred method for calculating the deflection of the pile body, according to the segmentation situation, the front row of piles can be divided into x+3 segments, x is the number of anchor cables applied, and the rear row of piles can be divided into 3 segments, resulting in a differential equation group of x+6 differential equations. Four boundary conditions are obtained at the top of the pile row, 4 (x+4) boundary conditions are obtained at each segment point, and four boundary conditions are obtained at the bottom of the pile row. According to the boundary conditions, a total of 4 (x+6) parametric equations are obtained; by solving the parametric equations, the bending moment, shear force, rotation angle, and displacement values ​​at any point on the pile body can be calculated.

[0037] The present invention also provides a device for calculating the deformation of a rock-soil combined stratum anchored double-row pile support structure, comprising:

[0038] The first determination module is used to determine the position of the sliding surface of the supporting structure;

[0039] The first processing module is used to obtain the differential equation of the pile body deflection of the front and rear rows of piles above the sliding surface according to the position of the sliding surface of the supporting structure;

[0040] The second processing module obtains the differential equation of the pile body deflection of the front and rear rows of piles below the slip surface according to the position of the slip surface of the supporting structure;

[0041] The second determination module is used to determine the different soil resistance distribution functions of the front and rear rows of piles in the rock-soil composite stratum;

[0042] A segmentation module is used to segment the front and rear row piles, and obtain the differential equations of each segment of the front and rear row piles according to the different soil resistance distribution functions of the front and rear row piles in the rock-soil composite stratum, the differential equations of the deflection of the front and rear row piles above the slip surface, and the differential equations of the deflection of the front and rear row piles below the slip surface;

[0043] A calculation module is used to calculate the pile deformation according to the differential equations of each segment.

[0044] Preferably, the segmentation module segments the front and rear rows of piles using a segmented independent coordinate method based on the synergy of piles and anchors.

[0045] Under the geological conditions of rock-soil combined strata, the soil resistance of the front and rear rows of piles in the rock-soil layer is taken into account, and the soil compression modulus between piles is regarded as a function that changes with depth to calculate the soil resistance. The synergy of the pile-anchor is taken into account, and the anchor tension of the anchor cable is considered to change with the actual displacement of the pile body. The short-term prestress loss of the anchor cable is considered, and the loss rate of the anchor cable prestress is segmented according to different rock-soil layers. The pile structure is divided into several pile units, and the pile body deflection differential equation is established in sections. The above improvements can be closer to the actual engineering situation, reduce the error in the calculation process of the force and deformation of the anchored double-row piles, and provide guarantee for the safe construction of the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a flow chart of the calculation method of the deformation of the rock-soil combined stratum anchored double-row pile support structure of the present invention;

[0047] Figure 2 Schematic diagram of overall force analysis of the support structure to determine the position of the slip surface;

[0048] Figure 3 It is a schematic diagram of the trapezoidal force analysis of each section of pile above the slip surface;

[0049] Figure 4 It is a schematic diagram of the force analysis of each section of pile below the slip surface;

[0050] Figure 5 It is a schematic diagram of the piecewise function of the soil resistance of the front and rear rows of piles. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0052] Embodiment 1:

[0053] like Figure 1 As shown, the present invention provides a method for calculating the deformation of a rock-soil combined stratum anchored double-row pile support structure considering the different rock-soil resistances of the front and rear row piles, comprising the following steps:

[0054] Step S1: Determine the position of the sliding surface of the supporting structure

[0055] like Figure 2 As shown, according to the limit equilibrium method, the assumed shear slip surface starts from the base of the front row of piles, and the slip shear slip surface starts from the base of the front row of piles. The angle between the slip surface and the vertical direction is Where L is the row spacing, which is the distance from the top of the front row of piles when the sliding surface extends to the ground. The active earth pressure is distributed according to the position of the sliding surface, and the distribution coefficient is:

[0056]

[0057] Where L represents the distance from the top of the front row pile when the sliding surface extends to the ground, α represents the earth pressure distribution coefficient, represents the internal friction angle of soil, L 0 It indicates the distance from the top of the front row pile when the sliding surface extends to the ground, and L indicates the distance between the front and rear rows of piles.

[0058] Step S2: derive the differential equations for the deflection of the front and rear rows of piles above the slip surface:

[0059] like Figure 3 As shown in Figure 2, assuming that the supporting structure above the sliding surface is subjected to external loads and lateral layered rock and soil pressure, the overall earth pressure of the supporting structure above the sliding surface can be expressed as:

[0060]

[0061] Where b is the distance between piles, F is the earth pressure strength of the soil above the i-th pile body acting on the supporting structure, γ n is the natural density of the nth layer of soil, H n is the thickness of the nth layer of soil, Z k is the thickness of the last layer of soil on the i-th pile, C k is the cohesion of the last layer of soil on the excavation section of the i-th pile, K ak is the Rankine earth pressure coefficient of the last layer of soil on the i-th pile body, and k represents the number of soil layers.

[0062] According to the elastic foundation beam theory, the front and rear rows of piles are regarded as semi-infinite elastic foundation beams. Assuming that the analysis section pile structure is a straight pile with a uniform cross-section, the moment of inertia I of the pile body is a constant, that is, the bending stiffness EI of the pile body is a constant. Therefore, the deflection equation of each section of the front and rear row of piles above the slip surface is obtained as follows:

[0063] Front pile:

[0064] Back pile:

[0065] Among them, q birepresents the overall soil pressure distribution behind the piles above the shear slip surface of the front row piles, q ai represents the overall soil pressure distribution behind the piles above the shear slip surface of the rear piles; EI represents the bending stiffness of the pile body, y bi represents the displacement of the i-th pile in the front row, y ai represents the displacement of the i-th pile in the rear row, z bi represents the length of the i-th section of the front row of piles, z ai Represents the length of the i-th section of the rear row of piles.

[0066] Step S3: derive the differential equations for the deflection of the front and rear piles below the slip surface:

[0067] The schematic diagram of pile body force and calculation coordinate direction below the slip surface are as follows: Figure 4 As shown in the figure, the soil load acting on the pile below the slip surface is a rectangular distribution, and the sudden change of the soil-rock interface is considered. Then the deflection equation of the front and rear rows of piles can be expressed as:

[0068] Front pile:

[0069] Back pile:

[0070] Among them, P b It represents the overall earth pressure on the supporting structure below the sliding surface of the front row piles, P a represents the overall earth pressure on the supporting structure below the sliding surface of the rear piles, p b (y,z) and p a (y,z) represent the different foundation reaction functions of the front and rear rows of piles in the rock and soil strata respectively.

[0071] Step S4: Determine the soil resistance distribution function of different front and rear piles in the rock-soil composite stratum

[0072] Analysis of soil resistance of front and rear piles Figure 5 As shown in the figure, the soil resistance distribution function of the front and rear rows of piles p = p (y, z) is expressed as follows:

[0073] Front pile:

[0074] Back pile:

[0075] Among them, P bs P represents the overall load on the pile side in the soil layer below the sliding surface of the front pile. as It represents the overall load on the pile side in the soil layer below the sliding surface of the rear pile, P br It represents the overall load on the pile side in the rock layer below the sliding surface of the front pile, P ar The overall load on the pile side in the rock layer below the sliding surface of the rear pile is shown in E s is the compression modulus of soil between piles, ybs represents the horizontal displacement of the front row piles in the soil layer below the sliding surface, y as represents the horizontal displacement of the rear row pile in the soil layer below the sliding surface; br represents the horizontal displacement of the front row piles in the rock layer below the slip surface, y ar Indicates the horizontal displacement of the rear row piles in the rock layer below the slip surface; br represents the length of the front row of piles in the rock layer below the sliding surface, z ar Indicates the length of the rear row of piles in the rock layer below the slip surface; z bs represents the length of the front row of piles in the soil layer below the sliding surface, z as Indicates the length of the rear row of piles in the soil layer below the sliding surface.

[0076] Step S5: Segment the front and rear rows of piles

[0077] The anchor cables in the support structure are assumed to be horizontal elastic supports, and the prestressing force when the anchor cables are locked is R 01 , considering the short-term prestress loss of the anchor cable, then: R = (1-ε)R 01 +K T y. ε is the anchor cable prestress loss rate, K T is the rigidity coefficient of the anchor cable, y is the displacement of the front row pile, and R is considered as a boundary condition in the segmented calculation.

[0078] The position of the sliding surface of the supporting structure, the position of the supporting structure such as the anchor cable, the rock-soil interface and the excavation surface are taken as sub-nodes, and the pile structure is divided into several independent units. Each independent unit establishes its own independent Cartesian coordinate system, and the pile deflection differential equation is established segmentally.

[0079] According to the piecewise independent coordinate method, if the anchored double-row piles have x anchor cables, the front and rear rows of piles above the slip surface can be divided into x+2 pile unit bodies, and x+2 piecewise deflection differential equations can be listed.

[0080] When there are rock and soil layers below the sliding surface, the front and rear piles can be divided into four sections, and the deflection equation of the pile in the soil can be listed as:

[0081] Front pile:

[0082] Back pile:

[0083] The differential equation for pile deflection in rock formation is:

[0084] Front pile:

[0085] Back pile:

[0086] Among them, P bsP represents the overall load on the pile side in the soil layer below the sliding surface of the front pile. as It represents the overall load on the pile side in the soil layer below the sliding surface of the rear pile, P br It represents the overall load on the pile side in the rock layer below the sliding surface of the front pile, P ar The overall load on the pile side in the rock layer below the sliding surface of the rear pile is shown in E s is the compression modulus of soil between piles, y bs represents the horizontal displacement of the front row piles in the soil layer below the sliding surface, y as represents the horizontal displacement of the rear row pile in the soil layer below the sliding surface; br represents the horizontal displacement of the front row piles in the rock layer below the slip surface, y ar Indicates the horizontal displacement of the rear row piles in the rock layer below the slip surface; br represents the length of the front row of piles in the rock layer below the sliding surface, z ar Indicates the length of the rear row of piles in the rock layer below the slip surface; z bs represents the length of the front row of piles in the soil layer below the sliding surface, z as Indicates the length of the rear row of piles in the soil layer below the sliding surface.

[0087] Step S6: Combine the differential equations of each segment to calculate the pile deformation

[0088] According to the segmentation, the front row of piles can be divided into x+3 segments, where x is the number of anchor cables, and the back row of piles can be divided into 3 segments. According to the above analysis, four boundary conditions can be obtained at the top of the double-row piles, 4(x+4) boundary conditions can be obtained at each segment point, and four boundary conditions can be obtained at the bottom of the double-row piles. According to these boundary conditions, a total of 4(x+6) parameter equations can be obtained. By solving these parameter equations, the unknowns of the general solution of the fourth-order differential equation obtained above and below the slip surface can be solved. The unknowns obtained by substituting the solved unknowns into the bending moment, shear force, rotation angle, and displacement expressions of each segment of the front and rear rows of the double-row piles can be obtained to obtain the specific values ​​of the bending moment, shear force, rotation angle, and displacement at any point of the pile body. The 4(x+6) parameter equations can solve 4(x+6) undetermined parameters, and then the solution of the differential equation of the entire deflection of the pile body can be obtained.

[0089] The method of the present invention takes into account the difference in the resistance distribution function of the rock and soil between the front and rear rows of piles below the sliding surface. In addition, it also takes into account the synergistic effect of the pile-anchor and the calculation of the pile body in sections using section-by-section independent coordinates. This can be more in line with the actual engineering situation, reduce the calculation error of the force and deformation of the anchored double-row pile support structure, especially the calculation error of the force and deformation of the rear row of piles, make the deformation calculation of the double-row pile support system more accurate, and ensure the safe excavation of the foundation pit.

[0090] Embodiment 2:

[0091] The present invention also provides a method and device for calculating the deformation of a rock-soil combined stratum anchored double-row pile support structure considering different rock and soil resistances of front and rear rows of piles, and the method for calculating the deformation of the rock-soil combined stratum anchored double-row pile support structure includes:

[0092] The first determination module is used to determine the position of the sliding surface of the supporting structure;

[0093] The first processing module is used to obtain the differential equation of the pile body deflection of the front and rear rows of piles above the sliding surface according to the position of the sliding surface of the supporting structure;

[0094] The second processing module obtains the differential equation of the pile body deflection of the front and rear rows of piles below the slip surface according to the position of the slip surface of the supporting structure;

[0095] The second determination module is used to determine the different soil resistance distribution functions of the front and rear rows of piles in the rock-soil composite stratum;

[0096] A segmentation module is used to segment the front and rear row piles by using a segmented independent coordinate method based on the synergistic effect of piles and anchors, and obtain the differential equations of each segment of the front and rear row piles according to the different soil resistance distribution functions of the front and rear row piles in the rock-soil composite stratum, the differential equations of the deflection of the front and rear row piles above the slip surface, and the differential equations of the deflection of the front and rear row piles below the slip surface;

[0097] A calculation module is used to calculate the pile deformation according to the differential equations of each segment.

[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A deformation calculation method for anchored double-row pile support structure in rock-soil combined strata, characterized in that: The following steps are involved: Determine the position of the sliding surface of the supporting structure; According to the position of the sliding surface of the supporting structure, the differential equation of the pile body deflection of the front and rear rows of piles above the sliding surface is obtained; According to the position of the sliding surface of the supporting structure, the differential equation of the pile body deflection of the front and rear rows of piles below the sliding surface is obtained; Determine the different soil resistance distribution functions of the front and rear rows of piles in the rock-soil composite strata; The piles in the front and rear rows are divided into sections by adopting the segmented independent coordinate method based on the synergistic effect of piles and anchors. The differential equations of the sections of the piles in the front and rear rows are obtained according to the different soil resistance distribution functions of the front and rear rows in the rock-soil composite strata, the differential equations of the deflection of the piles in the front and rear rows above the slip surface, and the differential equations of the deflection of the piles in the front and rear rows below the slip surface. Calculating pile deformation according to the differential equations of each segment; The differential equation for the deflection of the front and rear piles above the slip surface is: Front row: Back pile: Among them, q bi represents the overall soil pressure distribution behind the piles above the shear slip surface of the front row piles, q ai represents the overall soil pressure distribution behind the pile above the shear slip surface of the rear pile; EI represents the bending stiffness of the pile body, y bi represents the displacement of the i-th pile in the front row, y ai represents the displacement of the i-th pile in the rear row, z bi represents the length of the i-th section of the front row of piles, z ai represents the length of the i-th section of the rear row of piles; The differential equation for the deflection of the front and rear piles below the slip surface is: Front row: Back pile: Among them, P b P represents the overall earth pressure on the supporting structure below the sliding surface of the front row piles, a represents the overall earth pressure on the supporting structure below the sliding surface of the rear piles, p b (y,z) and p a (y,z) represent the different foundation reaction functions of the front and rear rows of piles in the rock and soil strata respectively.

2. The method for calculating deformation of a rock-soil combined stratum anchored double-row pile support structure according to claim 1 is characterized by: Assume that the shear slip surface starts from the base of the front row of piles, and the angle between the slip surface and the vertical direction is 45°-2 / The position equation of the sliding surface of the supporting structure is: Where L0 represents the distance from the top of the front row pile when the sliding surface extends to the ground, α represents the earth pressure distribution coefficient, represents the internal friction angle of the soil, L0 represents the distance from the top of the front row of piles when the sliding surface extends to the ground, and L represents the distance between the front and rear rows of piles.

3. The method for calculating the deformation of the deep foundation pit anchored double-row pile support structure according to claim 1 is characterized by: The distribution functions and values ​​of different soil resistance of front and rear piles in rock-soil composite strata are: Front row: Back pile: Where z≤h s Represents soil layer, z>h s Time represents rock layer, E s is the compression modulus of soil between piles, m r Represents the horizontal resistance coefficient of soil in the rock layer, m s Indicates the horizontal resistance coefficient of soil in the rock layer; z a Indicates the length of the rear pile, z b represents the length of the front row of piles; b0 represents the calculated width of the pile; y b represents the displacement of the front pile, y a Indicates the displacement of the rear pile; s y represents the distance between double-row piles, d represents the pile diameter; h represents the distance between double-row piles, d represents the pile diameter; s Represents the depth of soil, and n is the exponent of the power series function.

4. The method for calculating deformation of a rock-soil combined stratum anchored double-row pile support structure according to claim 1 is characterized by: According to the piecewise independent coordinate method, if the anchored double-row piles have x anchor cables, the pile bodies of the front and rear rows of piles above the slip surface can be divided into x+2 pile unit bodies, and x+2 piecewise deflection differential equation groups are listed respectively according to the deflection differential equations of the front and rear rows of piles above the slip surface.

5. The method for calculating the deformation of the deep foundation pit anchored double-row pile support structure according to claim 1 is characterized by: When there are rock and soil layers below the slip surface, the piles in the front and rear rows are divided into four sections. According to the deflection differential equation of the piles in the front and rear rows below the slip surface, the deflection equation of the pile in the soil is: Front row: Back pile: The differential equation for pile deflection in rock formation is: Front row: Back pile: Among them, P bs P represents the overall load on the pile side in the soil layer below the sliding surface of the front pile. as It represents the overall load on the pile side in the soil layer below the sliding surface of the rear pile, P br It represents the overall load on the pile side in the rock layer below the sliding surface of the front pile, P ar The overall load on the pile side in the rock layer below the sliding surface of the rear pile is shown in E s is the compression modulus of soil between piles, y bs represents the horizontal displacement of the front row piles in the soil layer below the sliding surface, y as represents the horizontal displacement of the rear row pile in the soil layer below the sliding surface; br represents the horizontal displacement of the front row piles in the rock layer below the slip surface, y ar Indicates the horizontal displacement of the rear row piles in the rock layer below the slip surface; br represents the length of the front row of piles in the rock layer below the sliding surface, z ar Indicates the length of the rear row of piles in the rock layer below the slip surface; z bs represents the length of the front row of piles in the soil layer below the sliding surface, z as Indicates the length of the rear row of piles in the soil layer below the sliding surface.

6. The method for calculating deformation of a rock-soil combined stratum anchored double-row pile support structure according to claim 1 is characterized by: The method for calculating the deflection of the pile body is as follows: according to the segmentation situation, the front row of piles can be divided into x+3 segments, x is the number of anchor cables applied, and the back row of piles can be divided into 3 segments, resulting in a total of x+6 differential equations. The top of the pile row obtains four boundary conditions, each segment point obtains 4(x+4) boundary conditions, and the bottom of the pile row obtains four boundary conditions. According to the 4(x+6) boundary conditions, x+6 parametric equations can be solved; by solving the parametric equations, the bending moment, shear force, rotation angle, and displacement values ​​at any point on the pile body can be obtained.

7. A device for calculating deformation of a rock-soil combined stratum anchored double-row pile support structure that implements the method for calculating deformation of a rock-soil combined stratum anchored double-row pile support structure as claimed in any one of claims 1 to 6, characterized in that: include: The first determination module is used to determine the position of the sliding surface of the supporting structure; The second processing module is used to obtain the differential equation of the pile body deflection of the front and rear rows of piles above the slip surface according to the position of the slip surface of the supporting structure; The first processing module obtains the differential equation of the pile body deflection of the front and rear rows of piles below the sliding surface according to the position of the sliding surface of the supporting structure; The second determination module is used to determine the different soil resistance distribution functions of the front and rear rows of piles in the rock-soil composite stratum; A segmentation module is used to segment the front and rear row piles, and obtain the differential equations of each segment of the front and rear row piles according to the different soil resistance distribution functions of the front and rear row piles in the rock-soil composite stratum, the differential equations of the deflection of the front and rear row piles above the slip surface, and the differential equations of the deflection of the front and rear row piles below the slip surface; A calculation module is used to calculate the pile deformation according to the differential equations of each segment.

8. The device for calculating deformation of a rock-soil combined stratum anchored double-row pile support structure according to claim 7, characterized in that: The segmentation module divides the front and rear rows of piles into segments using a segmented independent coordinate method based on the synergy of piles and anchors.

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