Method and device for determining prestress value of anchor cable of anchor pile

Abstract

The application relates to a method and device for determining the prestress value of an anchor cable of an anchor pile, which comprises the following steps: obtaining the design parameters of the anchor cable of the anchor pile; calculating the internal force of the anti-slide pile when no prestress is applied to the anchor cable according to the design parameters of the anchor cable; sequentially selecting initial prestress from a preset prestress value range, and calculating the anchor cable tension under each initial prestress according to the design parameters of the anchor cable and the internal force of the anti-slide pile when no prestress is applied to the anchor cable, as well as the internal force of the anti-slide pile and the displacement at the anchor cable under each anchor cable tension; generating a slide pile internal force diagram under the anchor cable tension according to the internal force of the anti-slide pile and the displacement at the anchor cable under each anchor cable tension; and determining the prestress value of the anchor cable of the anchor pile according to the slide pile internal force diagram under the anchor cable tension, so as to design the prestress of the anchor cable of the anchor pile, avoid the subjectivity, randomness and blindness in the selection of the prestress of the anchor cable, and improve the use reliability of the anchor pile.

Description

Technical Field

[0001] This application relates to the field of anchor pile technology, and in particular to a method and apparatus for determining the prestress value of anchor cables in anchor piles. Background Technology

[0002] With the development of science and technology and the continuous progress of society, foundation pit engineering has become an important part of building construction, municipal engineering, and rail transit engineering. Anchor piles, as a crucial component of foundation pit engineering, consist of anti-sliding piles and anchor cables. The design of anchor cables for anchor piles needs to address two key issues: first, determining the prestress of the anchor cables; and second, determining the anchor cable tension under long-term working conditions. Determining the prestress of the anchor cables is a critical issue in anchor pile design, directly affecting the reinforcement effect. How to design the prestress of the anchor cables to improve the reliability of anchor piles is an urgent problem to be solved. Summary of the Invention

[0003] Therefore, it is necessary to provide a method and apparatus for determining the prestress value of anchor cables in anchor piles, which can improve the reliability of anchor piles in use, in order to address the above problems.

[0004] A method for determining the prestress value of anchor cables in anchored piles includes:

[0005] Obtain the anchor cable design parameters for the anchored pile;

[0006] Based on the anchor cable design parameters, calculate the internal forces of the anti-slide pile without applying anchor cable prestress;

[0007] Initial prestresses are selected sequentially from the preset prestress value range. Based on the anchor cable design parameters and the internal force of the anti-slide pile without applying anchor cable prestress, the anchor cable tension under each initial prestress, the internal force of the anti-slide pile under each anchor cable tension, and the displacement at the anchor cable are calculated.

[0008] Based on the internal forces of the anti-slide pile under the action of anchor cable tension and the displacement at the anchor cable, generate the internal force diagram of the sliding pile under the action of anchor cable tension.

[0009] Based on the internal force diagram of the sliding pile under the action of the anchor cable tension, the anchor cable prestress value of the anchor pile is determined; the anchor cable prestress value is used for the anchor cable prestress design of the anchor pile.

[0010] In one embodiment, the internal forces of the anti-slide pile include the shear force and bending moment of the anti-slide pile; the calculation of the internal forces of the anti-slide pile without the application of anchor cable prestress includes:

[0011] Calculate the shear force and bending moment of the anti-slide pile under the action of landslide thrust when no anchor cable prestress is applied, as well as the shear force and bending moment at the sliding surface;

[0012] Calculate the rotation angle and rotation point of the anti-slide pile based on the shear force and bending moment at the sliding surface;

[0013] Based on the shear force and bending moment at the sliding surface, as well as the rotation angle and rotation point of the anti-slide pile, the shear force and bending moment of the anchorage section of the anti-slide pile are calculated; wherein, the shear force of the anti-slide pile includes the shear force of the loaded section and the shear force of the anchorage section, and the bending moment of the anti-slide pile includes the bending moment of the loaded section and the bending moment of the anchorage section.

[0014] In one embodiment, if the landslide thrust is triangular, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the landslide thrust are as follows:

[0015]

[0016]

[0017] Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section, and y represents the distance from the top of the pile.

[0018] In one embodiment, if the landslide thrust is rectangular, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the load-bearing section of the anti-slide pile under the action of landslide thrust are as follows:

[0019]

[0020]

[0021] Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section, and y represents the distance from the top of the pile.

[0022] In one embodiment, if the landslide thrust is trapezoidal, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the landslide thrust are as follows:

[0023]

[0024]

[0025] Among them, Q 1y and M1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section, and y represents the distance from the top of the pile.

[0026] In one embodiment, calculating the rotation angle and rotation point of the anti-slide pile based on the shear force and bending moment at the sliding surface includes:

[0027]

[0028]

[0029] Where Δφ1 and y 01 These are the turning angle and rotation point of the anti-slide pile, respectively, Q A and M A Let A represent the shear force and bending moment at the sliding surface, respectively; let A be the subgrade coefficient at the sliding surface; h2 be the anchorage length; m be the proportional coefficient of the sliding surface subgrade coefficient; and B be the shear force and bending moment at the sliding surface, respectively. p This is the calculated width of the anti-slide pile.

[0030] In one embodiment, calculating the shear force and bending moment of the anchorage section of the anti-slide pile based on the shear force and bending moment at the sliding surface, and the rotation angle and rotation point of the anti-slide pile, includes:

[0031]

[0032]

[0033] Among them, Q 1my and M 1my These are the shear force and bending moment of the anchorage section of the anti-slide pile, respectively.

[0034] In one embodiment, calculating the anchor cable tension under each initial prestress based on the anchor cable design parameters and the internal forces of the anti-slide pile without applied anchor cable prestress includes: calculating the anchor cable tension under each initial prestress based on the displacement-deformation compatibility equation, using the anchor cable design parameters and the internal forces of the anti-slide pile without applied anchor cable prestress; the displacement-deformation compatibility equation is:

[0035] ((y0+L1)Δφ+Δ 1q -Δ 11 )×cosθ1=δ1(R1-R 1O )

[0036] Where y0 is the distance from the rotation point of the anti-slide pile to the sliding surface, L1 is the height of the anchor cable from the sliding surface, Δφ is the rotation angle of the anti-slide pile around the rotation point, and Δ 1qΔ represents the displacement of the pile at the anchor point caused by the landslide thrust or soil pressure. 11 Let θ1 be the displacement of the pile at the anchor point under the action of anchor cable tension, δ1 be the downward inclination angle of the anchor cable relative to the horizontal direction, and R be the flexibility coefficient of the anchor cable. 1O R1 is the initial prestress of the anchor cable at the first anchor point, and R1 is the anchor cable tension under the initial prestress.

[0037] In one embodiment, the internal force diagram of the sliding pile includes a bending moment diagram, a shear force diagram, and an anchor cable tension increment diagram.

[0038] A device for determining the prestress value of anchor cables in anchored piles, comprising:

[0039] The parameter acquisition module is used to acquire the anchor cable design parameters of the anchor pile;

[0040] The first processing module is used to calculate the internal force of the anti-slide pile without applying anchor prestress based on the anchor cable design parameters.

[0041] The second processing module is used to sequentially select initial prestresses from a preset range of prestress values, and calculate the anchor cable tension under each initial prestress, as well as the anti-slide pile internal force and the displacement at the anchor cable under each anchor cable tension, based on the anchor cable design parameters and the internal force of the anti-slide pile when no anchor cable prestress is applied.

[0042] The data analysis module is used to generate a sliding pile internal force diagram under the action of anchor cable tension based on the internal forces of the anti-slide pile under the action of anchor cable tension and the displacement at the anchor cable.

[0043] The prestress determination module is used to determine the anchor cable prestress value of the anchor pile based on the internal force diagram of the sliding pile under the action of the anchor cable tension; the anchor cable prestress value is used for the anchor cable prestress design of the anchor pile.

[0044] The aforementioned method and apparatus for determining the prestress value of anchor cables in anchored piles calculates the internal forces of the anti-slide pile without applying anchor cable prestress based on the anchor cable design parameters. Then, it sequentially selects initial prestress values ​​from a preset range. Based on the anchor cable design parameters and the internal forces of the anti-slide pile without applying anchor cable prestress, it calculates the anchor cable tension under each initial prestress, as well as the internal forces and displacements at the anchor cables under each anchor cable tension. Based on the internal forces and displacements at the anchor cables under each anchor cable tension, it generates an internal force diagram of the anti-slide pile under the anchor cable tension. The anchor cable prestress value of the anchored pile is determined based on this diagram for designing the anchor cable prestress of the anchored pile. This avoids subjectivity, randomness, and blindness in the selection of anchor cable prestress, thus improving the reliability of the anchored piles. Attached Figure Description

[0045] Figure 1 This is a flowchart of a method for determining the prestress value of anchor cables in an embodiment;

[0046] Figure 2 This is a flowchart illustrating the calculation of the internal forces of the anti-slide pile without applying anchor cable prestress in one embodiment.

[0047] Figure 3 This is a schematic diagram of the calculation of the anchor pile in one embodiment;

[0048] Figure 4 This is a schematic diagram illustrating the calculation of internal forces in an anchor pile in one embodiment;

[0049] Figures 5-12 This is a diagram showing the bending moment distribution of the entire pile under the action of the anchor cable tension corresponding to the initial prestress of each anchor cable in one embodiment.

[0050] Figure 13 This is a schematic diagram of the anchor cable tension in one embodiment;

[0051] Figure 14 This is a distribution diagram of the incremental anchor tension corresponding to different initial prestresses of anchor cables in one embodiment.

[0052] Figure 15 This is a diagram showing the distribution of the maximum positive bending moment of the pile under the action of anchor cable tension corresponding to different initial prestresses of anchor cables in one embodiment.

[0053] Figure 16 A structural block diagram of a device for determining the prestress value of anchor cables in an embodiment of an anchor pile;

[0054] Figure 17 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0056] Currently, the method for determining the prestress value of anchor cables is to determine the anchor cable tension R through the displacement-deformation coordination method. An initial prestress R is applied to the anchor cable. o Value, calculated in R o The internal forces and deformations of the pile under load are analyzed. A displacement equilibrium equation is established based on the principle that the elongation of the anchor cable under long-term load is equal to the displacement of the pile at the anchor cable, in order to solve for the anchor cable tension R. This method considers the coordination between the elongation of the anchor cable and the deformation of the pile at the anchor cable under long-term load, as well as the resulting adjustments and changes in the anchor cable tension and internal forces of the pile; therefore, it is dynamic.

[0057] Although this method is reasonable for determining anchor cable tension, the selection of the initial prestress of the anchor cable is subjective, empirical, and random. Different initial prestresses R of the anchor cable... oi The value corresponds to different anchor cable tensions R. i The value corresponds to different anchor cable tension increments ΔR. i (ΔR i =R i -R oi When the initial prestress is at a low level, as R... oi As the value increases, ΔR i A rapid increase indicates a large adjustment range for the anchor cable tension; however, when R... oi After the value increases to a certain level, ΔR i The slower increase in prestress indicates limited room for adjustment of the anchor cable tension. This shows that when the anchor cable prestress exceeds a certain range, the pile-anchor structure operates under heavy loads. At this point, the adjustment space for the anchor cable tension is limited, making the anchor cable prone to breakage and affecting long-term stability and safety. Conversely, if the anchor cable prestress is too low, it fails to suppress deformation and improve the internal forces within the pile. Therefore, determining the anchor cable prestress becomes a crucial issue in the design and calculation of anchor piles.

[0058] Based on this, this application provides a method for determining the prestress value of anchor cables in anchored piles. According to the anchor cable design parameters, the internal forces of the anti-slide pile without applied anchor cable prestress are calculated. Then, initial prestresses are selected sequentially from a preset range of prestress values. Based on the anchor cable design parameters and the internal forces of the anti-slide pile without applied anchor cable prestress, the anchor cable tension under each initial prestress, as well as the internal forces and displacements at the anchor cables under each anchor cable tension, are calculated. Furthermore, based on the internal forces and displacements at the anchor cables under each anchor cable tension, an internal force diagram of the anti-slide pile under anchor cable tension is generated, determining the anchor cable prestress value for use in designing the anchor cable prestress of the anchored pile. This avoids subjectivity, randomness, and blindness in the selection of anchor cable prestress, improving the reliability of the anchored piles.

[0059] In one embodiment, such as Figure 1 As shown, a method for determining the prestress value of anchor cables in anchored piles is provided, including:

[0060] Step S100: Obtain the anchor cable design parameters for the anchored piles. The specific type of anchor cable design parameters is not unique and can be selected according to actual needs. For example, anchor cable design parameters may include the sliding surface ratio coefficient m (or sliding surface subgrade coefficient k), the subgrade coefficient A of the sliding surface, landslide thrust, anti-slide pile spacing, cantilever length h1, anchorage length h2, anchor point height L1, pile cross-sectional dimensions, concrete elastic modulus, number of anchor cable bundles, area of ​​a single bundle, and elastic modulus of the steel strand, etc. Specifically, the anchor cable design parameters of the anchored piles can be read by the processor's computer program and used to subsequently determine the anchor cable prestress value of the anchored piles.

[0061] Step S200: Calculate the internal forces of the anti-slide pile without applying anchor cable prestress based on the anchor cable design parameters.

[0062] After reading the anchor cable design parameters, the processor can first select a calculation mode based on these parameters. If the sliding bed ratio coefficient was read in the previous step, the m-method is selected; if the sliding bed foundation coefficient was read, the k-method is selected. After determining the calculation mode, the internal forces of the anti-slide pile without applying anchor cable prestress are calculated based on the anchor cable design parameters.

[0063] Step S300: Select initial prestresses sequentially from the preset prestress value range. Based on the anchor cable design parameters and the internal force of the anti-slide pile without applying anchor cable prestress, calculate the anchor cable tension under each initial prestress, as well as the internal force of the anti-slide pile and the displacement at the anchor cable under each anchor cable tension.

[0064] Correspondingly, the processor calculates the anchor cable tension based on a trial-and-error algorithm. After calculating the internal force of the anti-slide pile without applying anchor cable prestress, it sequentially selects the initial prestress R from the prestress value range (e.g., 0–2200 kN). oi By developing a computer program, all initial prestress R values ​​are calculated iteratively. oi Anchor cable tension R under action i The anchor cable tension is applied to the anti-slide pile, and the internal forces of the anti-slide pile and the displacement at the anchor cable are calculated.

[0065] In one embodiment, step S300 calculates the anchor cable tension under each initial prestress based on the anchor cable design parameters and the internal force of the anti-slide pile without applying anchor cable prestress, including: combining the anchor cable design parameters and the internal force of the anti-slide pile without applying anchor cable prestress, and calculating the anchor cable tension under each initial prestress based on the displacement deformation compatibility equation.

[0066] The specific type of displacement-deformation compatibility equation is not unique. Taking rigid piles as an example, the analysis process of the displacement-deformation compatibility equation for anchored piles is as follows:

[0067] 1) The pile and anchor cable are analyzed according to elastic stress, the anchor cable tension is considered as elastic support, the load-bearing section of the pile is calculated as a static structure, and the anchorage section of the pile is calculated as an elastic foundation beam.

[0068] 2) The friction between the pile and the surrounding soil and the reaction force at the bottom of the pile are not considered.

[0069] 3) The elongation of the anchor cable is equal to the displacement of the pile at the point of action of the anchor cable.

[0070] 4) The landslide was in a basically stable state before the anti-slide piles and anchor cables were completed.

[0071] According to the principle of displacement deformation coordination, the elongation of the anchor cable at each anchor point is equal to the displacement of the pile at that point, such as... Figure 3 As shown, the following displacement equilibrium equations are established.

[0072] f1cosθ1=Δ1 (1)

[0073] f1=(y0+L1)Δφ+Δ 1q -Δ 11 (2)

[0074] Δ1=δ1(R1-R 1O (3)

[0075]

[0076] q0 = q2 - q1

[0077] Δ 11 =R1·δ 11 (5)

[0078]

[0079]

[0080] Where y0 is the distance from the rotation point of the anti-slide pile to the sliding surface, L1 is the height of the anchor cable from the sliding surface, Δφ is the rotation angle of the anti-slide pile around the rotation point, and Δ 1q This represents the displacement of the pile at the anchor point caused by landslide thrust or soil pressure. Δ 11 δ represents the displacement of the pile at the anchor point under the action of anchor cable tension. 11 R is the displacement coefficient at the anchor point, determined by relevant calculation formulas in structural mechanics. 1O Let l1 be the initial prestress of the anchor cable at the first anchor point, R1 be the anchor cable tension under the initial prestress, θ1 be the downward inclination angle of the anchor cable relative to the horizontal direction, and δ1 be the anchor cable flexibility coefficient, i.e., the elastic elongation of the anchor cable under unit force. s E represents the length of the free section of the anchor cable and the area of ​​each bundle of anchor cables, respectively. gΔ is the elastic modulus of the anchor cable, N is the number of anchor cables per hole, and Δ1 is the elongation of the anchor cable at the first anchor point.

[0081] Combining equations (1), (2), (3), and (5), we obtain the displacement deformation compatibility equation:

[0082] ((y0+L1)Δφ+Δ 1q -Δ 11 )×cosθ1=δ1(R1-R 1O (7)

[0083] By solving the above equations, the tension of the anchor cable in its working state can be obtained as follows:

[0084] R1=(((y0+L1)Δφ+Δ 1q cosθ1+δ1R 1O ) / (δ1+δ 11 cosθ1) (8)

[0085] Equation (8) is the anchor cable tension equation. It can be seen that the anchor cable tension is not only related to the deformation of the anti-slide pile, but also closely related to the initial prestress value. By calculating the anchor cable tension corresponding to different initial prestresses and analyzing the relationship between the anchor cable displacement and the anchor cable tension increment, a suitable initial prestress value can be determined to achieve coordinated deformation of the anti-slide pile and the anchor cable.

[0086] Step S400: Generate the internal force diagram of the anti-slide pile under the action of anchor cable tension based on the internal forces of the anti-slide pile and the displacement at the anchor cable under the action of each anchor cable tension. After calculating the internal forces of the anti-slide pile and the displacement at the anchor cable under the action of each anchor cable tension, the processor stores the calculation results in a data file and automatically draws the internal force diagram of the anti-slide pile based on the internal forces of the anti-slide pile and the displacement at the anchor cable. Specifically, the internal force diagram of the anti-slide pile may include a bending moment diagram, a shear force diagram, and an anchor cable tension increment diagram.

[0087] Step S500: Determine the anchor cable prestress value of the anchored pile based on the internal force diagram of the sliding pile under the action of each anchor cable tension. The anchor cable prestress value is used for the anchor cable prestress design of the anchored pile. After drawing the internal force diagram of the sliding pile under the action of anchor cable tension, the processor can analyze the internal force diagram of the sliding pile in conjunction with the set judgment data to determine the anchor cable prestress value of the anchored pile; alternatively, the processor can display the internal force diagram of the sliding pile on a monitor for analysis by engineering designers to determine the anchor cable prestress value of the anchored pile. Specifically, engineering designers comprehensively analyze the bending moment diagram, shear force diagram, and anchor cable tension increment diagram of the entire pile segment (loaded segment and anchored segment) of the anti-sliding pile, and determine the anchor cable prestress value of the anchored pile by comprehensively analyzing key factors such as bending moment distribution characteristics, shear force distribution characteristics, and pile top displacement, thereby avoiding subjectivity, randomness, and blindness in the selection of anchor cable prestress value. All parameters required for calculation are automatically read by the processor's computer program, and the data file is automatically saved after the program completes the calculation.

[0088] The method described above for determining the prestress value of anchor cables in anchored piles involves calculating the internal forces of the anti-slide pile without applying anchor cable prestress based on the anchor cable design parameters. Then, initial prestresses are selected sequentially from a preset range of prestress values. Based on the anchor cable design parameters and the internal forces of the anti-slide pile without applying anchor cable prestress, the anchor cable tension under each initial prestress, as well as the internal forces and displacements at the anchor cables under each anchor cable tension, are calculated. Based on the internal forces and displacements at the anchor cables under each anchor cable tension, an internal force diagram of the anti-slide pile under anchor cable tension is generated. The anchor cable prestress value of the anchored pile is then determined based on this diagram for designing the anchor cable prestress of the anchored pile. This method avoids subjectivity, randomness, and blindness in the selection of anchor cable prestress, thus improving the reliability of the anchored piles.

[0089] Specifically, using a trial-and-error algorithm based on the deformation coordination principle, the corresponding anchor cable tension is calculated for each initial value (Roi, i = 1, 2, 3...n) within the initial prestress range of the anchor cable according to the following steps.

[0090] The first step is to calculate the internal forces of the anti-slide pile without applying anchor cable prestress.

[0091] The internal forces of the anti-slide pile include the shear force and bending moment. Further, the shear force of the anti-slide pile includes the shear force in the loaded section and the shear force in the anchorage section, and the bending moment of the anti-slide pile includes the bending moment in the loaded section and the bending moment in the anchorage section. For example... Figure 2 As shown, step S200, calculating the internal forces of the anti-slide pile without applying anchor cable prestress, includes:

[0092] Step S210: Calculate the shear force and bending moment of the anti-slide pile under landslide thrust when no anchor cable prestress is applied, as well as the shear force and bending moment at the sliding surface. When no anchor cable prestress is applied, the processor calculates the shear force Q of the loaded section under landslide thrust. 1yand bending moment M 1y and the shear force Q at the sliding surface A and bending moment M A .

[0093] Step S220: Calculate the rotation angle and rotation point of the anti-slide pile based on the shear force and bending moment at the sliding surface. Utilize the shear force Q at the sliding surface... A and bending moment M A The processor calculates the rotation angle Δφ1 and the rotation point y of the anti-slide pile. 01 .

[0094] Step S230: Calculate the shear force and bending moment of the anchorage section of the anti-slide pile based on the shear force and bending moment at the sliding surface, as well as the rotation angle and rotation point of the anti-slide pile. Calculate the shear force Q at the moving surface. A and bending moment M A And the rotation angle Δφ1 and rotation point y of the anti-slide pile 01 The processor can calculate the shear force Q of the anchorage section. 1my Bending moment M 1my And displacement at the anchor cable.

[0095] Practical research shows that landslide thrust generated by landslide bodies composed of different rock and soil components takes different forms. In step S210, the landslide thrust can be determined to be triangular, rectangular, or trapezoidal based on the properties of the landslide body. The corresponding formulas are then used to calculate the shear force and bending moment of the anti-slide pile under the action of landslide thrust.

[0096] In one embodiment, if the landslide thrust is triangular, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the action of landslide thrust are as follows:

[0097]

[0098]

[0099] Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section (unit: m), and y represents the height from the pile top (unit: m).

[0100] In one embodiment, if the landslide thrust is rectangular, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the action of landslide thrust are as follows:

[0101]

[0102]

[0103] Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section (unit: m), and y represents the height from the pile top (unit: m).

[0104] In one embodiment, if the landslide thrust is trapezoidal, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the landslide thrust are as follows:

[0105]

[0106]

[0107] Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section (unit: m), and y represents the height from the pile top (unit: m).

[0108] Furthermore, in step S210, after determining the calculation formula based on the type of landslide thrust and calculating the shear force and bending moment of the anti-slide pile under the action of landslide thrust, substituting y = h1 into the corresponding calculation formula yields the shear force Q at the sliding surface. A and bending moment M A .

[0109] The method for calculating the rotation angle and rotation point of the anti-slide pile is not unique. In one embodiment, step S220 includes:

[0110]

[0111]

[0112] Where Δφ1 and y 01 These are the turning angle and rotation point of the anti-slide pile, respectively, Q A M represents the shear force at the sliding surface (unit: kN). A Let A be the bending moment at the sliding surface (unit: kN·m), and let A be the subgrade coefficient at the sliding surface (unit: kN / m). 3 h2 is the length of the anchorage section (unit: m), and m is the proportional coefficient of the sliding bed subgrade (unit: kN / m). 4 ), Bp The calculated width of the anti-slide pile (unit: m).

[0113] In one embodiment, step S230 includes:

[0114]

[0115]

[0116] Among them, Q 1my and M 1my These are the shear force and bending moment of the anchorage section of the anti-slide pile, respectively.

[0117] Furthermore, based on the shear force and bending moment at the sliding surface, the displacement X1B at the proposed anchor cable can also be calculated:

[0118] X 1B =(L1+y 01 )Δφ1 (15)

[0119] At this point, the internal force calculation for the anti-slide pile without anchor cables is complete.

[0120] The second step is to calculate the initial prestress R of the anchor cable. O1 Internal forces of anti-slide piles under action.

[0121] Correspondingly, in step S300, the initial prestress R of the anchor cable is first calculated. O1 Shear force Q of the anti-slide pile under load 2y Bending moment M 2y The calculation diagram is shown below. Figure 4 The anchor cable is applied at point B of the anti-slide pile, at a height of L1 from the sliding surface.

[0122] AB segment: Q 2y =Q 1y M 2y =M 1y .

[0123] BO segment: Q 2y =Q 1y -R O1 (16)

[0124] M 2y =M 1y -R O1 ×(y+L1-h1) (17)

[0125] Then, calculate the shear force and bending moment at the sliding surface. When y = h1, obtain the shear force Q at the sliding surface. A2 and bending moment M A2 The calculation formula is as follows:

[0126] Q A2 =QA -R O1 (18)

[0127] M A2 =M A -R O1 ×L1 (19)

[0128] Further, calculate the rotation point and angle of the anti-slide pile. Let Q... A2 M A2 Replace Q in equations (11) and (12) respectively. A M A Calculate the rotation depth y of the anti-slide pile under the initial prestress of the anchor cable and the landslide thrust. 02 And the rotation angle Δφ2.

[0129] Further, step S300 calculates the shear force, bending moment, and displacement at the anchorage section. (The last part, "y", appears to be an error and doesn't translate directly.) 02 Δφ2 and Δφ2 respectively replace y in equations (13) to (15) 01 Δφ1 Calculate the shear force Q of the anti-slide pile anchorage section 2my Bending moment M 2my and pile top displacement X 2B .

[0130] The third step is to calculate the anchor cable tension.

[0131] In step S300, the displacement f1 of the anti-slip pile at anchor point B and the elongation Δ1 of the anchor cable are calculated according to equations (1) to (6). Combined with the displacement deformation coordination equation (7), the anchor cable tension equation (8) is solved to obtain the anchor cable tension R1.

[0132] The fourth step is to calculate the internal forces of the anti-slide pile and the displacement at the anchor cable under the action of the anchor cable tension.

[0133] In step S300, the anchor cable tension R1 is applied as an external load to the loaded section, and R1 replaces R. o1 Repeat the calculation in step two to obtain the shear force Q of the loaded section under the action of anchor cable tension R1. 3y Bending moment M 3y Shear force Q at the sliding surface A3 and bending moment M A3 and the rotation point y 03 The rotation angle Δφ3 and the shear force Q of the anchorage section 3my Bending moment M 3my and the displacement X at anchor point B 3B .

[0134] At this point, the initial prestress R of the anchor cable is... O1 The internal forces and pile top displacement of the anti-slide pile under the action of anchor cable tension R1 have been calculated.

[0135] The fifth step is to iteratively calculate the changes in anchor cable tension and anti-slide pile internal forces under the initial prestress of all anchor cables.

[0136] In step S300, the initial prestress value R of the anchor cable is taken. O2 R O2 =R O1 +Δ, where Δ is the prestress increment, and repeat the calculation process from steps two to four. Similarly, take the initial prestress value R of the anchor cable. O3 (R O3 =R O2 +Δ)……until the calculation of all initial prestress values ​​is completed, that is, the trial calculation ends.

[0137] Step 6: Draw the internal force diagram of the anti-slide pile under the action of anchor cable tension. Corresponding to step S400, draw the tension R of all anchor cables. i Shear force diagram, bending moment diagram, and anchor cable tension increment distribution diagram of the entire pile segment (loaded segment and anchorage segment) of the anti-slide pile under the action of (i=1,2……n).

[0138] Step 7: Determine the anchor cable prestress value. Corresponding to step S500, based on the results drawing from step 6, determine the distribution range of the initial prestress value of the anchor cable.

[0139] To better understand the above method for determining the prestress value of anchor cables in anchored piles, the following explanation is provided in conjunction with a trial calculation example.

[0140] The landslide body is composed of severely weathered sandstone and conglomerate, in a soil-like state, with a thickness of 10m. Below the sliding surface are slightly weathered mudstone and shale, with a subgrade coefficient A = 250,000 kN / m³. The calculated landslide thrust E... T =1000kN / m, remaining anti-sliding force E in front of the pile R =100kN / m, all in a rectangular distribution. The proposed anti-slide piles are 14m long, with a 4m anchorage section and a 6m spacing. The pile cross-section is 2m × 3m (width × height), and the pile's elastic modulus is 2.6 × 10⁻⁶. 7 kN / m 2 The landslide thrust is rectangular. One Nφ15.2 prestressed anchor cable is installed 1.0m below the pile top (N value varies with the initial prestress of the anchor cable). The prestress distribution range of the anchor cable is 0–2700kN, with prestress increasing by 100–200kN in increments of 20 levels. The anchor cable inclination angle is 20°, the free section length is 15m, and the area A of a single anchor cable bundle is... s =0.000139m2, the elastic modulus E of the anchor cable g =1.95×10⁸ kPa. The main calculation results under different initial prestress conditions are shown in Table 1.

[0141] Table 1

[0142]

[0143]

[0144] Figures 5-12 The diagram shows the bending moment distribution of the entire pile under the action of the anchor cable tension corresponding to the initial prestress of each anchor cable. The right line in the diagram represents the bending moment (unit: kN·m) of the anti-slip pile without anchor cables at the pile top; the top row of numbers indicates the maximum bending moment value, and the bottom row of numbers indicates the depth (unit: m) corresponding to the maximum bending moment value. The left line represents the bending moment (unit: kN·m) of the anchored pile; the top row of numbers indicates the maximum bending moment value, and the bottom row of numbers indicates the depth (unit: m) corresponding to the maximum bending moment value. The top of each diagram indicates the initial prestress value of the anchor cable and its corresponding anchor cable tension value (unit: kN); the dashed line at a depth of 10m indicates the location of the sliding surface.

[0145] The above data results illustrate the relationship between the initial prestress of the anchor cable and the anchor cable tension, the bending moment of the loaded section of the pile, and the bending moment of the anchorage section of the pile. These relationships can be summarized as follows:

[0146] 1) Anchor cable tension increases with the increase of initial prestress, but the rate of increase varies. For example... Figure 13 As shown: From left to right, the initial prestress (0-700kN) increases rapidly, i.e., the slope is large, which is the accelerated increase section; the middle section (700-1500kN) increases slowly, i.e. the slope becomes smaller, which is the decelerated increase section; the rear section (1500-2700kN) increases and then slows down again, i.e. the slope becomes smaller again, which is the slow increase section.

[0147] 2) as follows Figure 14 As shown, when the initial prestress value increases, in order to adapt to the displacement deformation coordination, the increment of anchor cable tension (the difference between anchor cable tension and initial prestress) also changes. From left to right, it can be roughly divided into an accelerating increase segment (initial prestress is 0 to 700 kN, with an upper limit of 700 kN), a decelerating increase segment (initial prestress is 700 to 1200 kN), and a negative increase segment (1700 to 2700 kN).

[0148] 3) As the anchor cable tension increases, the maximum positive bending moment of the anti-slide pile gradually decreases. However, the rate of decrease varies. For example... Figure 15 As shown: the initial prestress decreases rapidly in the first section (initial prestress of 0-700kN), i.e., the slope is large, which is the acceleration reduction section; the middle section (initial prestress of 700-1200kN) decreases more slowly, i.e. the slope becomes smaller, which is the deceleration reduction section; the last section (initial prestress of 1200-2700kN) increases, decreases and then slows down again, i.e. the slope becomes smaller again, and the curve shows two inflection points at 700-800kN and 1200-1300kN.

[0149] If the prestress value of the anchor cable is too small, the constraint on pile deformation is weak, and the reduction effect on the internal force of the pile is not significant, thus failing to fully utilize the function of the prestressed anchor cable. If the prestress value of the anchor cable is too large, the outer side of the anti-slide pile will be subjected to tensile force for a long time, affecting its service life. Therefore, its value is related to the stress state and economic rationality of the anchor cable pile. Based on engineering practice and theoretical calculations, and based on the principle of displacement deformation coordination, the following principles for determining the initial prestress value of the anchor cable are proposed by trial method:

[0150] 1) The initial prestress of the anchor cable should be distributed in the accelerating increasing segment of the anchor cable tension diagram and the anchor cable tension increment diagram, and in the accelerating decreasing segment of the maximum positive bending moment distribution diagram of the pile body. Within this range, the "potential" of the anchor cable tension is large, and its ability to adapt to long-term load changes is strong. The prestress value at the end of the accelerating increasing segment or the accelerating decreasing segment is taken as the upper limit of the initial prestress of the anchor cable pile.

[0151] 2) Considering the complexity of landslide environmental conditions (such as extreme rainfall conditions) and the long-term strength changes of soil and rock, it is recommended that the initial prestress value Roi of the anchor cable be taken as 60 to 80% of the upper limit of the initial prestress.

[0152] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0153] Based on the same inventive concept, this application also provides an apparatus for determining the prestress value of anchor cables in an anchor pile, which is used to implement the method for determining the prestress value of anchor cables in the above-described anchor pile. The solution provided by this apparatus is similar to the solution described in the above-described method. Therefore, the specific limitations of one or more apparatus embodiments for determining the prestress value of anchor cables in an anchor pile provided below can be found in the limitations of the method for determining the prestress value of anchor cables in the above-described method, and will not be repeated here.

[0154] In one embodiment, such as Figure 16 As shown, a device for determining the prestress value of anchor cables in anchored piles is provided, comprising: a parameter acquisition module 100, a first processing module 200, a second processing module 300, a data analysis module 400, and a prestress determination module 500, wherein:

[0155] The parameter acquisition module 100 is used to acquire the anchor cable design parameters of the anchor pile;

[0156] The first processing module 200 is used to calculate the internal force of the anti-slide pile without applying anchor cable prestress based on the anchor cable design parameters.

[0157] The second processing module 300 is used to sequentially select initial prestresses from a preset range of prestress values, and calculate the anchor cable tension under each initial prestress, as well as the anti-slide pile internal force and the displacement at the anchor cable under each anchor cable tension, based on the anchor cable design parameters and the internal force of the anti-slide pile when no anchor cable prestress is applied.

[0158] The data analysis module 400 is used to generate the internal force diagram of the sliding pile under the action of anchor cable tension based on the internal force of the anti-sliding pile under the action of each anchor cable tension and the displacement at the anchor cable.

[0159] The prestress determination module 500 is used to determine the prestress value of the anchor cable of the anchored pile based on the internal force diagram of the sliding pile under the action of anchor cable tension; the prestress value of the anchor cable is used for the prestress design of the anchor cable of the anchored pile.

[0160] In one embodiment, the internal forces of the anti-slide pile include the shear force and bending moment of the anti-slide pile; the first processing module 200 calculates the shear force and bending moment of the anti-slide pile under the action of landslide thrust when no anchor cable prestress is applied, as well as the shear force and bending moment at the sliding surface; based on the shear force and bending moment at the sliding surface, the rotation angle and rotation point of the anti-slide pile are calculated; based on the shear force and bending moment at the sliding surface, as well as the rotation angle and rotation point of the anti-slide pile, the shear force and bending moment of the anchorage section of the anti-slide pile are calculated; wherein, the shear force of the anti-slide pile includes the shear force of the loaded section and the shear force of the anchorage section, and the bending moment of the anti-slide pile includes the bending moment of the loaded section and the bending moment of the anchorage section.

[0161] Each module in the aforementioned device for determining the prestress value of anchor cables in anchored piles can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0162] In one embodiment, a computer device is provided, which may be a server, and its internal structure diagram may be as follows: Figure 17As shown. The computer device includes a processor, memory, and network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The database stores XX data. The network interface communicates with external terminals via a network connection. When executed by the processor, the computer program implements a method for determining the prestress value of anchor cables in anchored piles.

[0163] Those skilled in the art will understand that Figure 17 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0164] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the method described above.

[0165] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0166] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method described above.

[0167] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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, they should be considered to be within the scope of this specification.

[0168] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for determining the prestress value of anchor cables in anchored piles, characterized in that, include: Obtain the anchor cable design parameters for the anchored pile; Based on the anchor cable design parameters, calculate the internal forces of the anti-slide pile without applying anchor cable prestress; Initial prestresses are selected sequentially from the preset prestress value range. Based on the anchor cable design parameters and the internal force of the anti-slide pile without applying anchor cable prestress, the anchor cable tension under each initial prestress, the internal force of the anti-slide pile under each anchor cable tension, and the displacement at the anchor cable are calculated. Based on the internal forces of the anti-slide pile under the action of anchor cable tension and the displacement at the anchor cable, generate the internal force diagram of the sliding pile under the action of anchor cable tension. Based on the internal force diagram of the sliding pile under the action of the anchor cable tension, the anchor cable prestress value of the anchor pile is determined; the anchor cable prestress value is used for the anchor cable prestress design of the anchor pile.

2. The method according to claim 1, characterized in that, The internal forces of the anti-slide pile include the shear force and bending moment of the anti-slide pile; the calculation of the internal forces of the anti-slide pile without the application of anchor cable prestress includes: Calculate the shear force and bending moment of the anti-slide pile under the action of landslide thrust when no anchor cable prestress is applied, as well as the shear force and bending moment at the sliding surface; Calculate the rotation angle and rotation point of the anti-slide pile based on the shear force and bending moment at the sliding surface; Based on the shear force and bending moment at the sliding surface, as well as the rotation angle and rotation point of the anti-slide pile, the shear force and bending moment of the anchorage section of the anti-slide pile are calculated; wherein, the shear force of the anti-slide pile includes the shear force of the loaded section and the shear force of the anchorage section, and the bending moment of the anti-slide pile includes the bending moment of the loaded section and the bending moment of the anchorage section.

3. The method according to claim 2, characterized in that, If the landslide thrust is triangular, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the action of landslide thrust are as follows: Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section, and y represents the distance from the top of the pile.

4. The method according to claim 2, characterized in that, If the landslide thrust is rectangular, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the action of landslide thrust are as follows: Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section, and y represents the distance from the top of the pile.

5. The method according to claim 2, characterized in that, If the landslide thrust is trapezoidal, then without applying anchor cable prestress, the formulas for calculating the shear force and bending moment of the anti-slide pile under the action of landslide thrust are as follows: Among them, Q 1y and M 1y These represent the shear force and bending moment of the loaded section under landslide thrust without the application of anchor cable prestress; E T E represents the landslide thrust after the anti-slide pile. R The anti-slide pile front resistance is represented by h1, which is the height of the loaded section, and y represents the distance from the top of the pile.

6. The method according to claim 3, 4 or 5, characterized in that, The step of calculating the rotation angle and rotation point of the anti-slide pile based on the shear force and bending moment at the sliding surface includes: Where Δφ1 and y 01 These are the turning angle and rotation point of the anti-slide pile, respectively, Q A and M A Let A represent the shear force and bending moment at the sliding surface, respectively; let A be the subgrade coefficient at the sliding surface; h2 be the anchorage length; m be the proportional coefficient of the sliding surface subgrade coefficient; and B be the shear force and bending moment at the sliding surface, respectively. p This is the calculated width of the anti-slide pile.

7. The method according to claim 6, characterized in that, The calculation of the shear force and bending moment of the anchorage section of the anti-slide pile based on the shear force and bending moment at the sliding surface, as well as the rotation angle and rotation point of the anti-slide pile, includes: Among them, Q 1my and M 1my These are the shear force and bending moment of the anchorage section of the anti-slide pile, respectively.

8. The method according to claim 7, characterized in that, The step of calculating the anchor cable tension under each initial prestress based on the anchor cable design parameters and the internal forces of the anti-slide pile without applying anchor cable prestress includes: calculating the anchor cable tension under each initial prestress based on the displacement-deformation compatibility equation, using the anchor cable design parameters and the internal forces of the anti-slide pile without applying anchor cable prestress; the displacement-deformation compatibility equation is: ((y0+L1)Δφ+Δ 1q -D 11 )×cosθ1=δ1(R1-R 1O ) Where y0 is the distance from the rotation point of the anti-slide pile to the sliding surface, L1 is the height of the anchor cable from the sliding surface, Δφ is the rotation angle of the anti-slide pile around the rotation point, and Δ 1q Δ represents the displacement of the pile at the anchor point caused by the landslide thrust or soil pressure. 11 Let θ1 be the displacement of the pile at the anchor point under the action of anchor cable tension, δ1 be the downward inclination angle of the anchor cable relative to the horizontal direction, and R be the flexibility coefficient of the anchor cable. 1O R1 is the initial prestress of the anchor cable at the first anchor point, and R1 is the anchor cable tension under the initial prestress.

9. The method according to claim 8, characterized in that, The internal force diagram of the sliding pile includes a bending moment diagram, a shear force diagram, and an anchor cable tension increment diagram.

10. A device for determining the prestress value of anchor cables in anchored piles, characterized in that, include: The parameter acquisition module is used to acquire the anchor cable design parameters of the anchor pile; The first processing module is used to calculate the internal force of the anti-slide pile without applying anchor prestress based on the anchor cable design parameters. The second processing module is used to sequentially select initial prestresses from a preset range of prestress values, and calculate the anchor cable tension under each initial prestress, as well as the anti-slide pile internal force and the displacement at the anchor cable under each anchor cable tension, based on the anchor cable design parameters and the internal force of the anti-slide pile when no anchor cable prestress is applied. The data analysis module is used to generate a sliding pile internal force diagram under the action of anchor cable tension based on the internal forces of the anti-slide pile under the action of anchor cable tension and the displacement at the anchor cable. The prestress determination module is used to determine the anchor cable prestress value of the anchor pile based on the internal force diagram of the sliding pile under the action of the anchor cable tension; the anchor cable prestress value is used for the anchor cable prestress design of the anchor pile.

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