Method and device for acquiring internal force of double-row submerged pile, medium and equipment

Abstract

The invention discloses a double-row embedded pile internal force obtaining method, device, medium and equipment, and relates to the field of geotechnical engineering.The double-row embedded pile internal force obtaining method comprises the steps that according to the obtained pile length of the loaded section of a double-row anti-skid embedded pile, the landslide thrust sharing ratio of the front row and the rear row is determined, and the distribution form of landslide thrust and soil resistance of the front row and the rear row of piles is obtained; on the basis of the distribution form of landslide thrust and soil resistance of the front and rear rows of piles, the internal force of the load-bearing section of the front and rear rows of piles is determined by adopting a cantilever pile method, and on the basis of a foundation coefficient method, an anchoring section deflection differential equation is constructed by utilizing a finite difference method to obtain the internal force of the anchoring section of the front and rear rows of slide-resistant piles; accurate acquisition of the internal force of the double-row sinking and burying pile is achieved through the internal force of the load-bearing section and the internal force of the anchoring section of the front-row pile and the rear-row pile.

Description

Technical Field

[0001] The present invention relates to the technical field of geotechnical engineering, and particularly relates to a method, device, medium and equipment for obtaining the internal forces of double-row sunken piles. Background Technique

[0002] Landslides have become one of the most serious geological disasters affecting people's lives, production and life safety, posing a major threat and harm to the safety of local human settlements and urban construction. Therefore, landslide prevention and control has become a hot issue in geotechnical disaster prevention and mitigation.

[0003] In landslide prevention and control projects, the landslide thrust is mainly concentrated near the sliding surface, resulting in partial pile lengths of the load-bearing sections of anti-slide piles not being able to fully play their roles, causing a certain waste of pile lengths. This waste not only increases the project cost but may also affect the overall efficiency of anti-slide piles. A sunken anti-slide pile refers to an anti-slide pile that buries the entire pile body inside the slope and leaves a certain distance between the pile top and the slope surface. The sunken piles are mainly arranged near the sliding surface of the pile body. At this time, the pile body only bears part of the landslide thrust, and the remaining thrust beyond the pile top is resisted by the soil and rock mass itself. The internal force of the pile body is much smaller than that of a full-length pile. Existing research has shown that compared with full-length piles, sunken piles can effectively improve problems such as uneven force distribution and material waste. The length of the force-bearing section of the sunken anti-slide pile is shorter, which can save materials and reduce costs while ensuring the stability of landslide reinforcement. Due to its advantages of good anti-slide effect and economic investment, it has been applied to a certain extent in landslide treatment in recent years.

[0004] At present, the theoretical research on single-row sunken piles at home and abroad has been relatively complete. However, there is no unified design basis and construction specification for the design and calculation theory of double-row sunken piles, and it is still in its infancy. Since the soil pressure distribution forms of double-row sunken piles and single-row sunken piles are different, and their structural and force characteristics are also different, directly using the method for obtaining the internal forces of single-row piles may make it difficult to accurately obtain the internal forces of double-row sunken piles. Summary of the Invention

[0005] The present invention provides a method, device, medium and equipment for obtaining the internal forces of double-row sunken piles to solve the above problems existing in the prior art, that is, the problem of how to accurately obtain the internal forces of double-row sunken piles in the prior art. The present invention provides a method for obtaining the internal forces of double-row sunken piles, and the method includes:

[0006] Determine the sharing ratio of the landslide thrust of the front and rear rows according to the obtained pile length of the load-bearing section of the double-row anti-slide sunken piles, and obtain the distribution forms of the landslide thrust and soil resistance of the front and rear rows of piles according to the sharing ratio of the landslide thrust of the front and rear rows;

[0007] Based on the distribution forms of landslide thrust and soil resistance of the front and rear row piles, by adopting the cantilever pile method, the shear force and bending moment of the loaded sections of the front and rear row piles are determined. According to the shear force and bending moment of the loaded sections of the front and rear row piles, the internal forces of the loaded sections of the front and rear row piles are obtained;

[0008] Based on the foundation coefficient method, and using the finite difference method to construct the deflection differential equation of the anchored section. According to the deflection differential equation of the anchored section, by adopting the central difference format, the anchored sections of the front and rear row anti-slide piles are respectively discretized into multiple equal-length segments. The internal forces at each segmentation point are determined by numerical methods, and the central difference control equation is determined. According to the central difference control equation, combined with the boundary conditions at the pile bottom and the sliding surface of the anti-slide pile, the internal forces of the anchored sections of the front and rear row anti-slide piles are obtained;

[0009] Through the internal forces of the loaded sections and the anchored sections of the front and rear row piles, the internal forces of the double-row sunk piles are obtained.

[0010] Optionally, the specific steps of determining the shear force and bending moment of the loaded sections of the front and rear row piles by adopting the cantilever pile method include:

[0011] At a distance y from the pile top, the following formula is used to obtain the shear force and bending moment of the loaded section of the rear row pile:

[0012] When 0 < y ≤ h,

[0013]

[0014] When h < y ≤ h1,

[0015]

[0016] When y = h1, that is, at the sliding surface, the shear force and bending moment of the pile body are respectively:

[0017]

[0018] At a distance y from the pile top, the following formula is used to obtain the shear force and bending moment of the loaded section of the front row pile:

[0019] When 0 < y ≤ h2 - h1,

[0020]

[0021] When h2 - h1 < y ≤ h2,

[0022]

[0023] When y = h2, that is, at the sliding surface, the shear force and bending moment of the pile body are respectively:

[0024]

[0025] Wherein, Q yis the shear force of the pile body, M y is the bending moment, y is the distance from the pile top, q i is the landslide thrust, h i is the length of the pile above the slip surface, h is the distance from the pile top to the position of the maximum stress, h1 is the length of the loaded section of the rear row pile, p i is the soil resistance, i = 1, 2, 3, 1’, 2’, 3’.

[0026] Optionally, constructing the flexural differential equation of the anchored section by using the finite difference method specifically includes:

[0027]

[0028] where x is the horizontal displacement of the pile body, y is the distance from the pile top, k h is the foundation reaction coefficient at a certain depth of the embedded section, b0 is the calculated width of the pile, E is the elastic modulus of the anti-slide pile, and I is the section moment of inertia of the anti-slide pile.

[0029] Optionally, the boundary conditions at the bottom of the anti-slide pile and the slip surface specifically include:

[0030] For an elastic pile, the bottom of the pile is considered as a free end, that is, both the shear force and the bending moment are 0. From

[0031]

[0032] The boundary conditions at the pile bottom are obtained as:

[0033]

[0034] The following formula is used to obtain the boundary conditions at the slip surface of the rear row pile:

[0035]

[0036] The following formula is used to obtain the boundary conditions at the slip surface of the row pile:

[0037]

[0038] where E is the elastic modulus of the anti-slide pile, I is the section moment of inertia of the anti-slide pile, h is the distance from the pile top to the position of the maximum stress, M1 is the bending moment at the slip surface of the front and rear row piles, Q1 is the shear force at the slip surface of the front and rear row piles, x is the horizontal displacement of the pile body, and n is the node number.

[0039] Optionally, by using the transfer coefficient method and the rigid body limit equilibrium theory, the landslide thrust is determined, and in combination with the interaction between the pile and the soil, the internal force distribution of the pile body is determined. According to the internal force distribution of the pile body, the length of the loaded section of the double-row anti-slide sunken pile is obtained.

[0040] The present invention provides a device for obtaining the internal force of a double-row sunken pile, including:

[0041] A distribution form acquisition module, configured to determine the landslide thrust sharing ratio between the front row and the rear row according to the pile length of the loaded section of the double-row anti-slide immersed pile obtained, and obtain the distribution forms of the landslide thrust and soil resistance of the front row and rear row piles according to the landslide thrust sharing ratio between the front row and the rear row;

[0042] A loaded section internal force acquisition module, configured to determine the shear force and bending moment of the loaded section of the front row and rear row piles by using the cantilever pile method based on the distribution forms of the landslide thrust and soil resistance of the front row and rear row piles, and obtain the internal force of the loaded section of the front row and rear row piles according to the shear force and bending moment of the loaded section of the front row and rear row piles;

[0043] An anchored section internal force acquisition module, configured to construct a flexure differential equation of the anchored section by using the finite difference method based on the subgrade reaction method, and according to the flexure differential equation of the anchored section, discretize the anchored sections of the front row and rear row anti-slide piles into multiple equal-length segments by using the central difference format, determine the internal force of each segment division point by numerical method, determine the central difference control equation, and combine the boundary conditions at the pile bottom and the sliding surface of the anti-slide pile to obtain the internal force of the anchored sections of the front row and rear row anti-slide piles;

[0044] An internal force acquisition module for double-row immersed piles, configured to obtain the internal force of the double-row immersed piles through the internal force of the loaded section and the internal force of the anchored section of the front row and rear row piles.

[0045] The present invention provides a computer-readable storage medium storing a computer program, and when the computer program is executed by a processor, the above-mentioned method for obtaining the internal force of the double-row immersed pile is implemented.

[0046] The present invention provides a computer device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, and when the processor executes the program, the above-mentioned method for obtaining the internal force of the double-row immersed pile is implemented.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a method for obtaining the internal forces of double-row sunken piles. Based on the reasonable pile length of the loaded section of the double-row anti-slide sunken piles obtained, through carrying out physical model tests of double-row anti-slide sunken piles indoors, the deformation and failure laws of the piles and the distribution of internal forces along the pile body are analyzed, thereby providing a basis for the internal force calculation method of double-row sunken piles; According to the results of the model tests, the soil pressure distribution of the front and rear rows of piles is determined, and the internal forces of the loaded section are obtained by using the cantilever pile method; Using the foundation coefficient method, with the internal forces at the slip surface as the deformation coordination conditions, a flexure differential equation is constructed by using the finite difference method, and the flexure differential control equation is discretized into a central difference control equation. Combining the boundary conditions at the bottom of the anti-slide pile and the slip surface, the internal forces of the anchorage sections of the front and rear rows of piles can be obtained. Furthermore, based on the internal forces of the loaded section and the anchorage section, the internal forces of the double-row sunken piles can be accurately obtained; In addition, the landslide thrust, soil resistance and internal forces of the pile body are calculated by using the ABAQUS numerical simulation software, and the results of numerical simulation, theoretical calculation and model test are compared to verify the reliability of the method for obtaining the internal forces of the double-row sunken piles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings herein are incorporated into the specification and constitute a part of this specification, showing embodiments consistent with the present invention and, together with the specification, are used to explain the principles of the present invention.

[0049] Figure 1 It is a flowchart of a method for obtaining the internal forces of double-row sunken piles provided by an embodiment of the present invention;

[0050] Figure 2 It is a technical roadmap of a method for obtaining the internal forces of double-row sunken piles provided by an embodiment of the present invention;

[0051] Figure 3 It is the distribution form of the landslide thrust of the rear row of piles provided by an embodiment of the present invention;

[0052] Figure 4 It is the distribution form of the soil resistance in front of the rear row of piles provided by an embodiment of the present invention;

[0053] Figure 5 It is the load distribution form of the front row of piles provided by an embodiment of the present invention;

[0054] Figure 6 It is the calculation sketch of double-row sunken piles provided by an embodiment of the present invention;

[0055] Figure 7 It is the schematic diagram of the division of the pile body in the anchorage section provided by an embodiment of the present invention;

[0056] Figure 8 It is the schematic diagram of a computer device for a method for obtaining the internal forces of double-row sunken piles provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0057] To make the objectives, technical solutions and advantages of the present invention clearer, the following will, in conjunction with the accompanying drawings of the present invention, clearly and completely describe the technical solutions in the present invention. Obviously, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts fall within the scope of protection of the present invention.

[0058] The following will use specific embodiments to elaborate in detail on the technical solutions of the present invention and how the technical solutions of the present invention solve the above technical problems. These several specific embodiments below can be combined with each other, and concepts or processes that are the same or similar may not be repeated in some embodiments. The following will describe the embodiments of the present invention in conjunction with the accompanying drawings.

[0059] As Figure 1 and Figure 2 shown, a method for obtaining the internal forces of a double-row sunken pile shown in this embodiment includes:

[0060] S1: According to the pile length of the loaded section of the double-row anti-slide sunken pile obtained, determine the sharing ratio of the landslide thrust between the front and rear rows. According to the sharing ratio of the landslide thrust between the front and rear rows, obtain the distribution forms of the landslide thrust and soil resistance of the front and rear rows of piles.

[0061] Exemplarily, previous scholars derived the distribution functions of the landslide thrust behind the pile and the soil resistance in front of the pile according to the results of model tests for different geotechnical types, as shown in Table 1. Among them, the distribution intensity of the soil resistance along the pile height is represented by P, the pile length above the sliding surface is represented by h1, the landslide thrust at the position of the pile is represented by E, the soil resistance in front of the pile is represented by E', and the resultant force action points of the landslide thrust and soil resistance are represented by z0 and z0' respectively.

[0062] Table 1 Chart of the distribution functions of the landslide thrust and the soil in front of the pile

[0063]

[0064] Exemplarily, when determining the distribution form of the landslide thrust, the rear row of piles can be regarded as a single row of piles, and its landslide thrust distribution is basically the same as that of a single-row sunken pile. The landslide thrust received by the rear row of sunken piles can be regarded as two parts. One part is the action of the soil behind the pile on the pile body, showing a trapezoidal distribution, as shown in Figure 3 (a) of Figure 3 (b) of

[0065] The landslide thrust generated by the soil mass behind the rear row of piles is trapezoidally distributed, and its load magnitude can be calculated according to Table 1. The specific calculation formula is as follows:

[0066]

[0067] The landslide thrust q3 generated by the soil mass above the top of the rear row of piles causes the pile to bear a rectangular distributed load. The specific calculation formula for the landslide thrust is as follows:

[0068]

[0069] Among them, q1 is the landslide thrust generated by the rectangular distribution of the soil mass behind the rear row of piles, q2 is the landslide thrust generated by the triangular distribution of the soil mass behind the rear row of piles, q3 is the landslide thrust generated by the soil mass above the top of the rear row of piles, h1 is the pile length of the load-bearing section of the rear row of piles (the pile length above the sliding surface), H is the thickness of the landslide mass at the pile setting position, and E0 is the landslide thrust.

[0070] The pile body load distribution is trapezoidally distributed after superposition, as shown in (c) of Figure 3 .

[0071] Exemplarily, the resistance of the soil mass in front of the pile is related to factors such as the nature of the landslide and the scale of the landslide mass in front of the pile. In the present invention, it is assumed that the resistance of the soil mass in front of the pile is parabola-shaped, and the maximum resistance appears in the middle of the landslide mass. For the sake of simplified calculation, the resistance graph is simplified into a triangle and an inverted trapezoid. As shown in Figure 4 , the resistance of the soil mass in front of the pile is parabola-shaped. Given the resultant force P of the resistance in front of the pile and the distance G from the position of the resultant force action point to the sliding surface r , by making the shear force value and bending moment value at the sliding surface before and after simplification equal, the magnitudes of p1 and p2 can be obtained as follows:

[0072]

[0073] Among them, P represents the resistance of the soil mass in front of the pile, with the unit of kN / m; h1 represents the pile length of the load-bearing section of the rear row of piles, with the unit of m; L is the pile spacing, with the unit of m; η p is the ratio of the distance from the centroid of the resultant force of the resistance of the soil mass in front of the pile to the sliding surface to the pile length on the sliding surface, that is This value is about 10% - 15% higher than the centroid of the landslide thrust; h represents the distance from the position of the maximum stress to the top of the pile, and the value given in Table 2 is selected for reference according to the distribution form of the landslide thrust during calculation.

[0074] Table 2 Reference values of the height h from the top of the pile to the position of the maximum stress

[0075]

[0076] Exemplarily, the landslide thrust borne by the front-row piles consists of two parts. One part is the landslide thrust acting on the pile body by the rock and soil between the piles, and the other part is the landslide thrust generated by the soil on the pile top:

[0077] (1) The landslide thrust q′1 generated by the soil behind the front-row piles. Due to the effect of the rock and soil between the piles, the landslide thrust behind the rear-row piles (the section CP with the same length as the rear-row piles) is weakened when it is transmitted to the front-row piles. At this time, the landslide thrust transmitted by the soil behind the front-row piles is still rectangularly distributed, and the reduction coefficient can be selected as 0.683; for the part PD of the front-row piles that is higher than the rear-row piles, the landslide thrust generated by the soil behind the piles is equal to that of the rear-row piles, as shown in Figure 5 (a) of

[0078] The landslide thrust q′1 generated by the soil behind the front-row piles is obtained by using the following formula:

[0079]

[0080] where k is the reduction coefficient, k < 1;

[0081]

[0082] (2) The landslide thrust q′3 generated by the soil on the top of the front-row piles is equal to that of the rear-row piles and is rectangularly distributed, as shown in Figure 5 (b) of

[0083]

[0084] The load distribution on the pile body is superimposed, as shown in Figure 5 (c) of

[0085] As shown in Figure 6 , it is the force diagram of the double-row sunken piles for landslide reinforcement. The rear-row piles are subjected to the landslide thrust and the resistance of the rock and soil between the pile rows. The landslide thrust acting on the rear-row piles is trapezoidally distributed, and the resistance of the rock and soil in front of the piles is parabolically distributed. The force acting on the front-row piles is mainly the thrust of the rock and soil between the pile rows, which is irregularly distributed. Considering the risk of sliding of the soil in front of the front-row piles under the thrust, for the sake of safety, its influence is ignored and only used as a safety reserve.

[0086] Exemplarily, the sliding body thrust of the sunken section and the loaded section can be analyzed by the transfer coefficient method and with the help of the rigid body limit equilibrium theory. Combining the interaction between the piles and the soil, the internal force distribution of the pile body can be determined. According to the internal force distribution of the pile body, the pile length of the loaded section of the double-row anti-slide sunken piles can be obtained.

[0087] S2: Based on the distribution forms of landslide thrust and soil resistance of the front and rear row piles, by adopting the cantilever pile method, determine the shear force and bending moment of the loaded sections of the front and rear row piles, and obtain the internal forces of the loaded sections of the front and rear row piles according to the shear force and bending moment of the loaded sections of the front and rear row piles.

[0088] Since the distribution forms of the landslide thrust and the resistance behind the piles are known, for the convenience of calculation in the present invention, the cantilever pile method is used to calculate the shear force and bending moment of the loaded sections of the double-row anti-slide piles. The internal forces of the loaded sections of the front and rear row piles obtained in the present invention include the shear force and bending moment of the loaded sections.

[0089] (1) Rear row pile

[0090] Since the rear row pile can be regarded as a single-row anti-slide pile, the internal force calculation of the loaded section uses the cantilever pile method. Since there is a position of the maximum stress action point of the soil resistance in front of the pile in the loaded section, the cases of 0 < y ≤ h and h < y ≤ h1 are considered separately. As Figure 5 shown, at a distance y from the pile top, the pile body shear force Q y and the bending moment M y are as shown in the formula.

[0091] When 0 < y ≤ h,

[0092]

[0093] When h < y ≤ h1,

[0094]

[0095] When y = h1, that is, at the slip surface, the shear force and bending moment of the pile body are respectively:

[0096]

[0097] (2) Front row pile

[0098] The internal forces of the loaded section are solved by general statics. As Figure 6 shown, at a distance y from the pile top, the pile body shear force Q y and the bending moment M y are as shown in the formula.

[0099] When 0 < y ≤ h2 - h1,

[0100]

[0101] When h2 - h1 < y ≤ h2,

[0102]

[0103] When y = h2, that is, at the slip surface, the shear force and bending moment of the pile body are respectively:

[0104]

[0105] Among them, Q y is the shear force of the pile body, M y is the bending moment, y is the distance from the pile top, q i is the landslide thrust, h i is the length of the pile above the slip surface, p i is the soil resistance, i = 1, 2, 3, 1’, 2’, 3’.

[0106] S3: Based on the subgrade reaction method and using the finite difference method to construct the deflection differential equation of the anchored section. According to the deflection differential equation of the anchored section, by adopting the central difference format, the anchored sections of the front and rear row anti-slide piles are respectively discretized into multiple equal-length segments, and the internal forces at each segmentation point are determined by numerical methods to determine the central difference control equation. According to the central difference control equation, combined with the boundary conditions at the pile bottom and the slip surface of the anti-slide pile, the internal forces of the anchored sections of the front and rear row anti-slide piles are obtained.

[0107] The following is a specific description of the calculation process of the internal force of the anchored section.

[0108] (1) Determination of the anchorage depth

[0109] Ensure that the allowable compressive strength on the pile side is greater than the formation stress transferred by the anti-slide pile to the formation below the slip surface. The lateral wall compressive stress σ of the pile body on the formation max (t / m 2 ) satisfies the following conditions:

[0110]

[0111] In the formula, γ is the unit weight of the rock and soil mass (t / m 3 ), and y is the depth from the ground to the calculation point (m).

[0112] (2) Calculation of the internal force of the pile body in the anchored section

[0113] The anchored section can be regarded as a laterally loaded pile with a horizontal load acting on the pile top, and the subgrade reaction method is used for solution. Based on the Euler-Bernoulli beam theory, the unified differential control equation of the deflection of the anchored sections of the front and rear row anti-slide piles can be expressed as:

[0114]

[0115] Among them, x is the horizontal displacement of the pile body, m; y is the distance from the pile top, m; k h is the subgrade reaction coefficient at a certain depth of the embedded section, kN / m 3 ; b0 is the calculated width of the pile, m; E is the elastic modulus of the anti-slide pile, kN / m 3 ; I is the moment of inertia of the cross-section of the anti-slide pile, m 4 .

[0116] A large number of model tests and engineering practices have shown that the results of structural calculations using the finite difference method are safe, accurate and reliable. Compared with the traditional power series solution method, the calculation process is more convenient, eliminating the cumbersome table - looking process for designers. Therefore, this invention combines the existing finite difference method to calculate the internal forces of the anchorage section of double - row immersed piles.

[0117] ① Central difference format

[0118] As Figure 7 shown, the anchorage sections of the front and rear row anti - slide piles are respectively discretized into n equal - length segments, each segment with a length of h. Between the slip surface and the pile bottom, the nodes are numbered in sequence as 3, 4, 5…, n + 3. Two virtual nodes are added above the slip surface and below the pile bottom, with a total of n + 5 nodes. The pile - soil interaction in the anchorage section is described by a linear soil spring model.

[0119] The central difference control equations for the anchorage sections of the front and rear row piles are the same:

[0120]

[0121] That is

[0122]

[0123] ② Boundary conditions

[0124] Four boundary conditions at the pile bottom and the slip surface of the anti - slide pile are supplemented. For the pile bottom of an elastic pile, it is considered as a free end, that is, both the shear force and the bending moment are 0. From

[0125]

[0126] The pile bottom boundary conditions are obtained as:

[0127]

[0128] The shear force and bending moment at the slip surface of the front and rear row piles can be determined by the boundary continuity conditions. Therefore, the boundary conditions at the slip surface of the rear row pile are:

[0129]

[0130] Similarly, the boundary conditions at the slip surface of the front row pile are:

[0131]

[0132] ③ Matrix operation formula

[0133] For the n + 1 nodes of the anti - slide pile anchorage section, n + 1 equations can be listed. By supplementing 4 boundary conditions, 5 equations are obtained, and then the pile body displacements x i at the n + 5 nodes can be solved.

[0134] Let By combining the differential control equations at each node of the anti-slide pile and the four boundary conditions at the pile bottom and the slip surface, the matrix linear equations of the anchored section of the anti-slide pile can be obtained as follows:

[0135] [K i [X i = [H i

[0136] wherein, [K i is the coefficient matrix, [X i is the pile body displacement matrix, and [H i is the load matrix;

[0137] Among them,

[0138]

[0139] Thus, the deformation matrix operation formula of the anchored section of the anti-slide pile can be constructed, and the finite difference numerical solution process of each node of the pile body can be solved using the Python language, which improves the calculation efficiency compared with the complex solution process of the existing finite difference method using the continuity condition at the slip surface for repeated iteration.

[0140] The pile body displacements x i of the front and rear row anti-slide piles can be calculated according to the following matrix operation formula:

[0141]

[0142] After obtaining the pile body displacement [x i , the rotation angle, shear force value and bending moment value of the pile body can be calculated through the following formulas:

[0143]

[0144] S4: Obtain the internal forces of the double-row embedded piles through the internal forces of the loaded sections and the anchored sections of the front and rear row piles.

[0145] Exemplarily, after obtaining the internal forces of the double-row embedded piles, a numerical simulation analysis of the test model was carried out using the ABAQUS finite element software, and the theoretical calculation values and the test measured values were compared. The results show that the distribution forms of the pile body soil pressure and internal forces obtained by the three methods are basically the same, and the theoretical calculation results are slightly larger than the numerical simulation and model test values. This is because when assuming the distribution form of the pile body soil pressure, safety considerations are taken, resulting in larger calculated shear force and bending moment values, but the error is small, verifying the reliability of the internal force calculation formula of the double-row anti-slide embedded piles proposed by the present invention.

[0146] ​The above is the method for obtaining the internal forces of double-row sunken piles provided by one or more embodiments of this specification. Based on the same idea, this specification also provides a corresponding device for obtaining the internal forces of double-row sunken piles, including:

[0147] A distribution form acquisition module, configured to determine the sharing ratio of landslide thrust between the front row and the rear row according to the pile length of the loaded section of the double-row anti-slide sunken piles obtained, and obtain the distribution forms of the landslide thrust and soil resistance of the front row and the rear row according to the sharing ratio of landslide thrust between the front row and the rear row;

[0148] A loaded section internal force acquisition module, configured to determine the shear force and bending moment of the loaded section of the front row and the rear row by using the cantilever pile method based on the distribution forms of the landslide thrust and soil resistance of the front row and the rear row, and obtain the internal forces of the loaded section of the front row and the rear row according to the shear force and bending moment of the loaded section of the front row and the rear row;

[0149] An anchored section internal force acquisition module, configured to construct a deflection differential equation of the anchored section based on the foundation coefficient method and using the finite difference method, discretize the anchored sections of the front row and the rear row anti-slide piles into multiple equal-length segments respectively by adopting the central difference format according to the deflection differential equation of the anchored section, determine the internal forces at each segmentation point by numerical methods, determine the central difference control equation, and obtain the internal forces of the anchored sections of the front row and the rear row anti-slide piles in combination with the boundary conditions at the bottom of the anti-slide pile and the sliding surface;

[0150] An internal force acquisition module for double-row sunken piles, configured to obtain the internal forces of the double-row sunken piles through the internal forces of the loaded sections and the internal forces of the anchored sections of the front row and the rear row.

[0151] For the specific limitations on the device for obtaining the internal forces of double-row sunken piles, reference can be made to the limitations on the method for obtaining the internal forces of double-row sunken piles in the above text, which will not be elaborated here. Each module in the above device for obtaining the internal forces of double-row sunken piles can be implemented in whole or in part through software, hardware, and their combinations. The above-mentioned modules can be embedded in the processor of the computer device in hardware form or be independent of it, or can be stored in the memory of the computer device in software form, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules.

[0152] The present invention also provides a computer-readable storage medium, which stores a computer program, and the computer program can be used to execute the method for obtaining the internal forces of double-row sunken piles provided above.

[0153] The present invention also provides Figure 8 The structural schematic diagram of the computer device shown, as Figure 8As shown in the figure, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include other hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to implement the method for obtaining the internal force of the double-row sunken piles provided in the above embodiments.

[0154] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in the present invention.

Claims

1. A method for obtaining internal forces of double-row buried piles, characterized in that: Including: Based on the pile length of the loaded section of the double-row anti-slide sunken pile obtained, determine the sharing ratio of the landslide thrust between the front row and the back row. According to the sharing ratio of the landslide thrust between the front row and the back row, obtain the distribution forms of the landslide thrust and soil resistance of the front row and back row piles; Based on the distribution forms of the landslide thrust and soil resistance of the front row and back row piles, by using the cantilever pile method, determine the shear force and bending moment of the loaded section of the front row and back row piles. According to the shear force and bending moment of the loaded section of the front row and back row piles, obtain the internal forces of the loaded section of the front row and back row piles; Based on the foundation coefficient method and using the finite difference method to construct the deflection differential equation of the anchorage section. According to the deflection differential equation of the anchorage section, by adopting the central difference format, discretize the anchorage sections of the front row and back row anti-slide piles into multiple equal-length segments respectively. Determine the internal forces at each segmentation point by numerical methods, determine the central difference control equation. According to the central difference control equation, combined with the boundary conditions at the bottom of the anti-slide pile and the slip surface, obtain the internal forces of the anchorage sections of the front row and back row anti-slide piles; Through the internal forces of the loaded section and the internal forces of the anchorage section of the front row and back row piles, obtain the internal forces of the double-row sunken pile.

2. The method for obtaining internal forces of double-row buried piles as claimed in claim 1, characterized in that: The specific steps of determining the shear force and bending moment of the loaded section of the front row and back row piles by using the cantilever pile method include: At a distance y from the pile top, use the following formula to obtain the shear force and bending moment of the loaded section of the back row pile: When 0 < y ≤ h, When h < y ≤ h1, When y = h1, that is, at the slip surface, the shear force and bending moment of the pile body are respectively: At a distance y from the pile top, use the following formula to obtain the shear force and bending moment of the loaded section of the front row pile: When 0 < y ≤ h2 - h1, When h2 - h1 < y ≤ h2, When y = h2, that is, at the slip surface, the shear force and bending moment of the pile body are respectively: Among them, Q y is the pile shear force, M y is the bending moment, y is the distance from the pile top, q i is the landslide thrust, h i is the length of the pile above the sliding surface, h is the distance from the maximum stress position to the pile top, h1 is the length of the loaded section of the rear row of piles, and p i is the soil resistance, i=1,2,3,1',2',3'.

3. The method for obtaining internal forces of double-row buried piles as claimed in claim 1, characterized in that: The specific steps of constructing the deflection differential equation of the anchorage section by using the finite difference method include: Among them, x is the horizontal displacement of the pile body, y is the distance from the pile top, and k h is the foundation reaction coefficient at a certain depth of the embedded section, b0 is the calculated width of the pile, E is the elastic modulus of the anti-sliding pile, and I is the section moment of inertia of the anti-sliding pile.

4. The method for obtaining internal forces of double-row buried piles as claimed in claim 1, characterized in that: The boundary conditions at the bottom of the anti-slide pile and the slip surface specifically include: For the bottom of the elastic pile considered as a free end, that is, both the shear force and the bending moment are 0, from The bottom boundary condition of the pile is obtained as: Use the following formula to obtain the boundary condition at the slip surface of the back row pile: Use the following formula to obtain the boundary condition at the slip surface of the row pile: Where, E is the elastic modulus of the anti-slide pile, I is the sectional moment of inertia of the anti-slide pile, h is the distance from the position of the maximum stress to the pile top, M1 is the bending moment at the slip surface of the front row and back row piles, Q1 is the shear force at the slip surface of the front row and back row piles, x is the horizontal displacement of the pile body, and n is the node number.

5. The method for obtaining internal forces of double-row buried piles as claimed in claim 1, characterized in that: By using the transfer coefficient method and the rigid body limit equilibrium theory, determine the landslide thrust. Combined with the interaction between the pile and the soil, determine the internal force distribution of the pile body. According to the internal force distribution of the pile body, obtain the pile length of the loaded section of the double-row anti-slide sunken pile.

6. A double-row buried pile internal force acquisition device, characterized in that: Including: A distribution form acquisition module, which is used to determine the sharing ratio of the landslide thrust between the front row and the back row according to the pile length of the loaded section of the double-row anti-slide sunken pile obtained, and obtain the distribution forms of the landslide thrust and soil resistance of the front row and back row piles according to the sharing ratio of the landslide thrust between the front row and the back row; A loaded section internal force acquisition module, which is used to determine the shear force and bending moment of the loaded section of the front row and back row piles by using the cantilever pile method based on the distribution forms of the landslide thrust and soil resistance of the front row and back row piles, and obtain the internal forces of the loaded section of the front row and back row piles according to the shear force and bending moment of the loaded section of the front row and back row piles; Anchorage segment internal force acquisition module, which is used to construct anchorage segment deflection differential equation based on foundation coefficient method and finite difference method, discretize the anchorage segments of front and rear rows of anti-sliding piles into multiple equal-length segments by adopting central difference format according to the anchorage segment deflection differential equation, determine the internal force of each segment division point by numerical method, determine central difference control equation, and obtain the internal force of the anchorage segments of front and rear rows of anti-sliding piles according to the central difference control equation combined with the boundary conditions at the bottom of the anti-sliding pile and the sliding surface; The internal force acquisition module of the double-row sunk piles is used to acquire the internal force of the double-row sunk piles through the internal force of the load section and the internal force of the anchor section of the front and rear rows of piles.

7. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method for obtaining the internal force of double-row buried piles according to any one of claims 1 to 5 is implemented.

8. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, the method for obtaining the internal force of double-row buried piles as claimed in any one of claims 1 to 5 is implemented.

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