A method for optimizing prestressing of multiple rows of anchor cables

Abstract

The present invention relates to a method for optimizing the prestressing force of multiple rows of anchor cables, belonging to the technical field of anchor cable prestressing optimization. The method comprises the following steps: S1: constructing a bored pile support structure model containing multiple rows of anchor cables in numerical simulation software; S2: uniformly determining the baseline prestressing force of all anchor cables; S3: obtaining the corresponding optimal prestressing force for each row of anchor cables based on the baseline prestressing force, and obtaining the optimal bending moment of the bored pile based on the corresponding optimal prestressing force for each row of anchor cables; S4: performing a secondary adjustment on the optimal prestressing force for each row of anchor cables to obtain the final prestressing force for all anchor cables. This method can accurately determine the optimal prestressing force for each row of anchor cables, effectively improving the stability of the bored pile support structure, and has high practical value.

Description

Technical Field

[0001] The invention belongs to the technical field of anchor cable prestress optimization, and in particular belongs to a multi-row anchor cable prestress optimization method. Background Art

[0002] In existing geotechnical engineering practices, bored cast-in-place pile support structures are commonly used in scenarios such as slope stabilization and deep foundation pit support. As a common bored cast-in-place pile reinforcement method, the prestressing force of anchor cables directly affects the performance of the entire support structure.

[0003] Traditional prestressing methods often rely on empirical estimation and lack a comprehensive optimization solution for multi-row anchor systems. Empirical estimation can lead to problems such as uneven prestressing and poor support effects. Summary of the Invention

[0004] The multi-row anchor cable prestressing optimization method of the present invention can comprehensively optimize the prestressing of the multi-row anchor cable system.

[0005] A method for optimizing prestressing of multiple rows of anchor cables according to the present invention comprises the following steps:

[0006] S1: Construct a bored pile support structure model containing multiple rows of anchor cables in numerical simulation software;

[0007] S2: Uniformly determine the reference prestress of all anchor cables;

[0008] S3: Based on the reference prestress, the corresponding optimal prestress of each row of anchor cables is obtained, and the first optimal bending moment peak value generated by the bored pile is obtained according to the optimal prestress corresponding to each row of anchor cables;

[0009] S4: Secondary adjustment of the optimal prestress of each row of anchor cables to obtain the second optimal bending moment peak value generated by the bored piles;

[0010] Determine whether the second optimal bending moment peak meets the set standard. If so, obtain the prestress of each row of anchor cables corresponding to the second optimal bending moment peak;

[0011] If it does not meet the requirements, the optimal prestress in S3 is adjusted three times to obtain the third optimal bending moment peak value generated by the bored pile; and whether the third optimal bending moment peak value meets the set standard is judged again.

[0012] And so on...

[0013] Assuming that the Vth optimal bending moment peak value meets the standard, the prestress of each row of anchor cables corresponding to the Vth optimal bending moment peak value is obtained.

[0014] Furthermore, step S2 includes the following steps:

[0015] S2.1: In the numerical simulation software, apply prestress P to all anchor cables. m , m∈{1,2,……,n}, apply prestress to all anchor cables n times, and the prestress applied to all anchor cables in each prestressing is the same;

[0016] As the number of times the prestress is applied increases, m increases accordingly, and the applied prestress P m Also increases accordingly; the difference between two adjacent prestressing forces:

[0017] S2.2: When all anchor cables are subjected to a certain prestressing force P m When the external load and anchor cable force are combined, the bored pile will produce a corresponding bending moment peak;

[0018] The peak bending moment is expressed as follows: when all anchor cables are subjected to the same or different prestress, different bending moments will be generated at each cross section of the bored pile. Assuming there are G cross sections in total, the bored pile will generate G bending moments. The moment with the largest absolute value among the G bending moments is the peak bending moment.

[0019] When all anchor cables are subjected to n prestress P m When the prestress P of each anchor cable is m Different, so the bored piles produce different peak moments; all anchor cables are added with n prestress P m , bored piles generate n bending moment peaks; select the smallest bending moment peak among the n bending moment peaks and record it as M o,min ;

[0020] S2.3: According to the numerical simulation software, M o,min Input into the numerical simulation software to obtain the prestress P at this time o,min ;P o,min It is used as the benchmark prestress for all anchor cables.

[0021] Furthermore, step S3 includes the following steps:

[0022] S3.1: Number each row of anchor cables from top to bottom, denoted by k, where k∈{1,2,3,4,5};

[0023] S3.2: Apply prestress P to anchor cable number k = 1 j , j∈{3,4,……,n}, prestress P j As j increases, the difference in adjacent prestressing forces increases. The anchor cable with number k=1 is prestressed n-2 times. Each time the anchor cable with number k=1 is prestressed, the anchor cables with other numbers maintain the reference prestress P. o,min ;

[0024] The anchor cable number k=1 is prestressed with P j , other anchor cables maintain the reference prestress P o,min When the peak bending moment of bored pile is obtained, the anchor cable numbered k=1 is applied with n-2 prestress P j , bored piles generate a total of n-2 bending moment peaks;

[0025] Apply prestress P to the anchor cable numbered k=2 j , j∈{3,4,……,n}, prestress P j As j increases, the difference in adjacent prestressing forces increases. ; The anchor cable with number k=2 is prestressed n-2 times. Each time the anchor cable with number k=2 is prestressed, the anchor cables with other numbers maintain the reference prestress P o,min ;

[0026] The anchor cable number k=2 is prestressed with P j , other anchor cables maintain the reference prestress P o,min When the peak bending moment of bored pile is obtained, the anchor cable numbered k=2 is applied with n-2 prestress P j , bored piles generate a total of n-2 bending moment peaks;

[0027] And so on...

[0028] S3.3: Apply prestress P to anchor cable number k = 1 j When , compare n-2 bending moment peaks and select the smallest bending moment peak among n-2 bending moment peaks; record it as

[0029] The anchor cable number k=2 is prestressed with P j When the bored pile generates n-2 bending moment peaks, the smallest bending moment peak among the n-2 bending moment peaks is selected; it is recorded as

[0030] And so on...

[0031] The minimum bending moment peak values ​​of anchor cables numbered 1 to 5 are recorded as follows:

[0032]

[0033] S3.4: Enter the values ​​in the numerical simulation software Each time the above-mentioned minimum bending moment peak is input into the numerical simulation software, the numerical simulation software will output an optimal prestress accordingly;

[0034] Assume that the numerical simulation software input When the numerical simulation software outputs the corresponding optimal prestress

[0035] Input into numerical simulation software When the numerical simulation software outputs the corresponding optimal prestress

[0036] And so on...

[0037] The optimal prestress outputted for each of the above minimum bending moment peaks is:

[0038]

[0039] S3.5: Input all the optimal prestresses in S3.4 into the numerical simulation software simultaneously. Corresponding to the optimal prestress applied by anchor cable No. 1, This corresponds to the optimal prestress applied to the anchor cable numbered 2; and so on..., all numbered anchor cables correspond to the optimal prestress applied;

[0040] The peak bending moment generated by the bored pile at this time is obtained and set as the first optimal bending moment peak, recorded as t=1.

[0041] Furthermore, step S4 includes the following steps:

[0042] S4.1: Set t = 1, L = 2;

[0043] S4.2: Prestress the anchor cable numbered k = 1. L∈{2,3,4,5,…,}, t∈{1,2,3,4,5,…,}; suppose that a total of u prestressing forces are applied, and u changes with the values ​​of L and t; the anchor cables with other numbers maintain the optimal prestressing force;

[0044] The anchor cable number k=1 is prestressed with P y When the anchor cables with other numbers maintain the optimal prestress, the anchor cable with number k=1 is given the prestress P y The peak bending moment generated by the bored pile is u times; a total of u prestressing forces are applied, and the bored pile generates u peak bending moments, which are recorded as

[0045] Apply prestress to the anchor cable numbered k=2 L∈{2,3,4,5,…,}, t∈{1,2,3,4,5,…,}; suppose that a total of u prestressing forces are applied, and u changes with the values ​​of L and t; the anchor cables with other numbers maintain the optimal prestressing force;

[0046] The anchor cable number k=2 is prestressed with P y When the bored pile generates the corresponding bending moment peak, a total of u prestressing forces are applied, and a total of u bending moment peaks are generated by the bored pile, which are recorded as ...、

[0047]

[0048] And so on...

[0049] S4.3: Select the bending moment peak with the smallest absolute value among all the bending moment peaks generated by bored piles in S4.2 and set it as the t+1th optimal bending moment peak, recorded as and obtain The final prestress of each numbered anchor cable corresponding to the following;

[0050] S4.4: Calculate the optimal bending moment ratio using the formula:

[0051]

[0052] S4.5: If ε<5%, it meets the set parameter standard and outputs the value in S4.3. The final prestress of each numbered anchor cable corresponding to the following;

[0053] Otherwise, the set parameter standard is not met; if the set parameter standard is not met, then t=t+1 and L=L+1 are substituted into S4.2-S4.5 and the cycle is repeated; assuming: Then the final prestress of each numbered anchor cable under the Vth optimal bending moment peak is output.

[0054] Beneficial effects:

[0055] This solution accurately determines the optimal prestressing force for each row of anchor cables, which can effectively improve the stability of the bored pile support structure and has high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Figure 1 It is a flow chart of this optimization method.

[0057] Figure 2 This is the bored cast-in-place pile support structure model constructed in Example 1.

[0058] Figure 3 Displacement cloud diagram and bending moment diagram of bored piles when a uniform baseline prestress of 400kN is applied to all anchor cables. Figure 3 a is the displacement cloud diagram of bored pile; Figure 3 b is the bending moment diagram of bored cast-in-place piles.

[0059] Figure 4Displacement cloud diagram and bending moment diagram of bored cast-in-place pile under optimal prestressing. Figure 4 a is the displacement cloud diagram of bored pile under optimal prestress, Figure 4 b is the bending moment diagram under optimal prestress.

[0060] Figure 5 Displacement cloud diagram and bending moment diagram of bored cast-in-place piles when final prestress is applied to the anchor cables of each number. Figure 5 a is the displacement nephogram of bored piles when the final prestress is applied to each anchor cable; Figure 5 b is the bending moment diagram of bored piles when the final prestress is applied to each numbered anchor cable. DETAILED DESCRIPTION

[0061] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0062] See Figure 1 , a multi-row anchor cable prestressing optimization method, comprising the following steps:

[0063] S1: In numerical simulation software, a bored pile support structure model containing multiple rows of anchor cables is constructed.

[0064] In this embodiment, a bored pile support structure model including five rows of anchor cables is constructed, with each row of anchor cables positioned at a different height within the model. Figure 2 This is the model of the five-row bored pile support structure constructed in S1.

[0065] S2: Uniformly determine the baseline prestressing force of each row of anchor cables.

[0066] The specific steps include:

[0067] S2.1: In the numerical simulation software, all anchor cables are moved from P1 to P at the same time. n , the prestress is increased evenly and gradually. In this embodiment, n=7; the applied prestresses are P1, P2, ..., P7 respectively. A total of 7 prestresses are applied.

[0068] Difference in application of adjacent prestressing forces

[0069] When all anchor cables are uniformly prestressed with P1, the peak bending moment generated by the bored pile is assumed to be M1;

[0070] When all anchor cables are uniformly prestressed with P2, the peak bending moment generated by the bored pile is assumed to be M2;

[0071] And so on...

[0072] When all anchor cables are uniformly prestressed with P7, the peak bending moment generated by the bored pile is assumed to be M7;

[0073] M1, M2, ..., M7 are obtained by numerical simulation software. For example, in the numerical simulation software, the prestress of all anchor cables is set to P1. The numerical simulation software gives the bending moment at each cross section of the bored pile. Assuming there are G cross sections, there are G bending moments. Comparing these G bending moments, the bending moment with the largest absolute value is the peak bending moment M1.

[0074] In this embodiment, P1=0kN; P n =P7=600kN.

[0075]

[0076] S2.2: All anchor cables shall be uniformly prestressed from P1 to P n When the minimum bending moment peak value of bored pile is selected, it is recorded as M o,min ;

[0077] The formula is: M o,min =min{|M1|, |M2|, |M3|, |M4|, |M5|, |M6|, |M7|};

[0078] S2.3: According to the numerical simulation software, M o,min Input into the numerical simulation software to obtain the prestress P at this time o,min ;P o,min It is used as the benchmark prestress for all anchor cables.

[0079] In this embodiment, the values ​​of the uniform prestress applied to each row of anchor cables and the corresponding peak bending moments generated by the bored piles are recorded in Table 1.

[0080] Table 1: Peak bending moment, minimum bending moment and reference prestress of bored piles under various prestressing conditions

[0081]

[0082]

[0083] From Table 1 we can see that:

[0084] When all anchor cables are uniformly prestressed with 0 kN, the peak bending moment M1 generated by the bored pile is 4145.598 kN·m;

[0085] When all anchor cables are uniformly prestressed with 100 kN, the peak bending moment M2 generated by the bored pile is 3169.498 kN·m;

[0086] And so on...

[0087] As shown in Table 1, when all anchor cables are uniformly prestressed with 400 kN, the bending moment peak value generated by the bored pile is the smallest, and the minimum bending moment peak value M o,min =M5=1125.824kN·m; at this time, the reference prestress P corresponding to M5 o,min It is 400kN.

[0088] Therefore, 400kN is uniformly used as the benchmark prestress for all anchor cables.

[0089] Figure 3 Displacement cloud diagram and bending moment diagram of bored piles when a uniform baseline prestress of 400kN is applied to all anchor cables. Figure 3 a is the displacement cloud diagram of bored pile; Figure 3 b is the bending moment diagram of bored cast-in-place piles.

[0090] S3: The prestress of each row of anchor cables is adjusted separately to obtain the optimal prestress corresponding to each row of anchor cables, and the first optimal bending moment peak value of the bored cast-in-place pile corresponding to the optimal prestress of each row of anchor cables is obtained.

[0091] The specific steps include:

[0092] S3.1: Number each row of anchor cables from top to bottom, denoted by k, where k∈{1,2,3,4,5};

[0093] S3.2: Increase the prestress of the anchor cable numbered k=1 gradually and evenly from P3, P4, ..., P7, and apply the difference between adjacent prestresses. Other anchor cables maintain the reference prestress P o,min ;

[0094] S3.3: The prestressing forces applied to the anchor cable with number k=1 are P3, P 4、 ..., P7, other anchor cables maintain the reference prestress P o,min When the bending moment peaks of bored piles are obtained, the prestressing force is applied 5 times for the anchor cable with the number k=1, and there are 5 corresponding bending moment peaks, which are recorded as Select The minimum bending moment peak value is denoted as

[0095]

[0096] The prestress of the anchor cable with number k=2 is gradually and evenly increased from P3, P4, ..., P7, and the anchor cables with other numbers maintain the reference prestress P o,min For the anchor cable with number k=2, 5 prestressing forces are applied, and there are 5 corresponding bending moment peaks, which are recorded as The minimum bending moment peak value of the anchor cable numbered k=2 is recorded as

[0097] And so on...

[0098] S3.4: Obtain the minimum peak bending moment of bored piles when all anchor cables are applied P3, P4, ..., P7, that is,

[0099] S3.5: Enter the values ​​in the numerical simulation software The minimum peak bending moment generated by each bored pile above corresponds to the optimal prestress applied by the bored pile;

[0100] Assume that the peak bending moment of bored pile is When , the optimal prestress output in the numerical simulation software is Input into numerical simulation software When the numerical simulation software outputs the corresponding optimal prestress

[0101] By analogy, we can obtain the optimal prestress of bored piles under different minimum bending moment peaks, which are recorded as The results are shown in Table 2.

[0102] Table 2 Peak bending moment of bored piles, minimum bending moment of bored piles, and optimal prestress corresponding to minimum bending moment of bored piles for anchor cables of different numbers under prestress of P3, P4, ..., P7.

[0103]

[0104]

[0105] From Table 2, we know that when the anchor cable with number k=1 is subjected to 200kN prestress, the anchor cables with other numbers are subjected to the reference prestress P o,min =400kN, the peak bending moment of bored pile is 937.4796506kN·m;

[0106] Take the anchor cable with number k=1 as an example. When the anchor cable with number k=1 is subjected to 300kN prestress, the anchor cables with other numbers are subjected to the reference prestress P o,min =400kN, the peak bending moment of bored pile is 890.9176138kN·m;

[0107] And so on...

[0108] For the anchor cable with number k=1, a prestress of 600kN is applied, and for the anchor cables with other numbers, a reference prestress of P is applied. o,min =400kN, the peak bending moment of bored pile is 1626.10372kN·m;

[0109] According to Table 2 again, when the anchor cable with number k=1 is prestressed with 300kN and the anchor cables with other numbers maintain the reference prestress, the peak bending moment of the bored pile is the smallest. The minimum peak bending moment of the bored pile is At this time, the optimal prestress corresponding to the anchor cable number k=1

[0110] And so on...

[0111] The optimal prestress corresponding to each numbered anchor cable is:

[0112] S3.6: Input the optimal prestress corresponding to each of the above-mentioned anchor cables into the numerical simulation software simultaneously. Corresponding to the optimal prestress applied by anchor cable No. 1, The optimal prestress applied by anchor cable No. 2 is obtained by analogy. The first optimal bending moment peak value generated by the bored pile is obtained. t=1, the results are shown in Table 3.

[0113] Table 3: Bending moments of bored piles under the corresponding optimal prestressing conditions for each anchor cable number.

[0114]

[0115] From Table 3, we know that

[0116] The first optimal bending moment peak value of bored piles under the optimal prestress corresponding to each numbered anchor cable It is 798.394 kN·m.

[0117] Figure 4 Displacement cloud diagram and bending moment diagram of bored cast-in-place pile under optimal prestressing. Figure 4 a is the displacement cloud diagram of bored pile under prestress, Figure 4 b is the bending moment diagram under optimal prestress.

[0118] S4: Secondary adjustment of the optimal prestress of each row of anchor cables to obtain the final prestress of all anchor cables.

[0119] The specific steps include:

[0120] S4.1: Let t = 1; L = 2;

[0121] S4.2: Apply prestress P to the anchor cable numbered k=1 y， L∈{2,3,4,5,…,}, t∈{1,2,3,4,5,…,}; suppose that a total of u prestressing forces are applied, and u changes with the values ​​of L and t; the anchor cables with other numbers maintain the optimal prestressing force;

[0122] The anchor cable number k=1 is prestressed with P y When the bored pile generates the corresponding bending moment peak, a total of u prestressing forces are applied, and a total of u bending moment peaks are generated by the bored pile, which are recorded as ...、

[0123] Apply prestress P to the anchor cable numbered k=2 y , L∈{2,3,4,5,…,}, t∈{1,2,3,4,5,…,}; suppose that a total of u prestressing forces are applied, and u changes with the values ​​of L and t; the anchor cables with other numbers maintain the optimal prestressing force;

[0124] The anchor cable number k=2 is prestressed with P y When the anchor cables with other numbers maintain the optimal prestress, the anchor cable with number k=2 is given the prestress P y The peak bending moment generated by the bored pile is u times; a total of u prestressing forces are applied, and the bored pile generates u peak bending moments, which are recorded as

[0125] And so on...

[0126] S4.3: Select the bored pile with the smallest peak bending moment and record it as Set as the t+1th optimal bending moment peak; and obtain The final prestress of each numbered anchor cable corresponding to the following;

[0127] S4.4: Calculate the optimal bending moment ratio using the formula:

[0128]

[0129] S4.5: If ε<5%, output S4.3 t=1, the final prestress of each corresponding anchor cable;

[0130] If ε<5% does not hold, set t=t+1, L=L+1, and repeat S4.2-S4.5 until ε<5% holds. Assumptions: If it is established, the final prestress of each anchor cable under the Vth optimal bending moment peak value is output.

[0131] See Table 4 for specific data.

[0132] Table 4 Peak bending moment of each numbered anchor cable, minimum peak bending moment of bored piles and corresponding final prestress of each numbered anchor cable.

[0133]

[0134]

[0135] From Table 4, we know that

[0136] When the anchor cable numbered k=1 is prestressed with 200 kN alone and the anchor cables numbered other are prestressed with the corresponding optimal stress, the peak bending moment of the bored pile is 852.0647338 kN·m.

[0137] When the anchor cable numbered k=1 is prestressed with 250 kN alone and the anchor cables numbered other are prestressed with the corresponding optimal stress, the peak bending moment of the bored pile is 825.6372451 kN·m.

[0138] And so on...

[0139] When t=1, and from Table 4, when the anchor cable numbered k=4 is prestressed with 450kN alone and the anchor cables numbered other are prestressed with the corresponding optimal stress, the minimum bending moment peak value generated by all bored piles is It is 766.8573363 kN·m, that is, the second optimal bending moment peak is 766.8573363 kN·m.

[0140] Because when t=1,L=2, Therefore, the conditions for establishment are met. According to Table 4, the output The corresponding final prestressing forces are, i.e., 300kN, 300kN, 500kN, 450kN, and 300kN;

[0141] Figure 5 It is the displacement cloud diagram and bending moment diagram of bored piles when the final prestress is applied to each numbered anchor cable. Figure 5 a is the displacement nephogram of bored piles when the final prestress is applied to each anchor cable; Figure 5 b is the bending moment diagram of bored piles when the final prestress is applied to each numbered anchor cable.

[0142] With the above-described preferred embodiments of the present invention as a guide, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A method for optimizing the prestressing of multiple rows of anchor cables, characterized in that: The following steps are involved: S1: Construct a bored pile support structure model containing multiple rows of anchor cables in numerical simulation software; S2: Uniformly determine the reference prestress of all anchor cables; S3: Based on the reference prestress, the corresponding optimal prestress of each row of anchor cables is obtained, and the first optimal bending moment peak value generated by the bored pile is obtained according to the optimal prestress corresponding to each row of anchor cables; S4: Secondary adjustment of the optimal prestress of each row of anchor cables to obtain the second optimal bending moment peak value generated by the bored piles; Determine whether the second optimal bending moment peak meets the set standard. If so, obtain the prestress of each row of anchor cables corresponding to the second optimal bending moment peak; If it does not meet the requirements, the optimal prestress in S3 is adjusted three times to obtain the third optimal bending moment peak value generated by the bored pile; and whether the third optimal bending moment peak value meets the set standard is judged again. And so on... Assuming that the Vth optimal bending moment peak value meets the standard, the prestress of each row of anchor cables corresponding to the Vth optimal bending moment peak value is obtained; wherein step S2 includes the following steps: S2.1: In the numerical simulation software, apply prestress P to all anchor cables. m , m∈{1,2,……,n}, apply prestress to all anchor cables n times, and the prestress applied to all anchor cables in each prestressing is the same; As the number of times the prestress is applied increases, m increases accordingly, and the applied prestress P m Also increases accordingly; the difference between two adjacent prestressing forces: S2.2: When all anchor cables are subjected to a certain prestressing force P m When the external load and anchor cable force are combined, the bored pile will produce a corresponding bending moment peak; The peak bending moment is expressed as follows: when all anchor cables are subjected to the same or different prestress, different bending moments will be generated at each cross section of the bored pile. Assuming there are G cross sections in total, the bored pile will generate G bending moments. The moment with the largest absolute value among the G bending moments is the peak bending moment. When all anchor cables are subjected to n prestress P m When the prestress P of each anchor cable m Different, so the bored piles produce different peak moments; all anchor cables are added with n prestress P m , bored piles generate n bending moment peaks; select the smallest bending moment peak among the n bending moment peaks and record it as M o,min ; S2.3: According to the numerical simulation software, M o,min Input into the numerical simulation software to obtain the prestress P at this time o,min ;P o,min It is used as the benchmark prestress for all anchor cables.

2. A multi-row anchor cable prestressing optimization method according to claim 1, characterized in that: Step S3 includes the following steps: S3.1: Number each row of anchor cables from top to bottom, denoted by k, where k∈{1,2,3,4,5}; S3.2: Apply prestress P to anchor cable number k = 1 j , j∈{3,4,……,n}, prestress P j As j increases, the difference in adjacent prestressing forces increases. The anchor cable with number k=1 is prestressed n-2 times. Each time the anchor cable with number k=1 is prestressed, the anchor cables with other numbers maintain the reference prestress P. o,min ; The anchor cable number k=1 is prestressed with P j， Other anchor cables maintain the reference prestress P o,min When the peak bending moment of bored pile is obtained, the anchor cable numbered k=1 is applied with n-2 prestress P j , bored piles generate a total of n-2 bending moment peaks; Apply prestress P to the anchor cable numbered k=2 j , j∈{3,4,……,n}, prestress P j As j increases, the difference in adjacent prestressing forces increases. The anchor cable with number k=2 is prestressed n-2 times. Each time the anchor cable with number k=2 is prestressed, the anchor cables with other numbers maintain the reference prestress P o,min ; The anchor cable number k=2 is prestressed with P j , other anchor cables maintain the reference prestress P o,min When the peak bending moment of bored pile is obtained, the anchor cable numbered k=2 is applied with n-2 prestress P j , bored piles generate a total of n-2 bending moment peaks; And so on... S3.3: Apply prestress P to anchor cable number k = 1 j When , compare n-2 bending moment peaks and select the smallest bending moment peak among n-2 bending moment peaks; record it as The anchor cable number k=2 is prestressed with P j When , the bored pile generates n-2 bending moment peaks. Compare the n-2 bending moment peaks and select the smallest bending moment peak among the n-2 bending moment peaks; record it as And so on... The minimum bending moment peak values ​​of anchor cables numbered 1 to 5 are recorded as follows: S3.4: Enter the values ​​in the numerical simulation software Each time the above-mentioned minimum bending moment peak is input into the numerical simulation software, the numerical simulation software will output an optimal prestress accordingly; Assume that the numerical simulation software input When the numerical simulation software outputs the corresponding optimal prestress Input into numerical simulation software When the numerical simulation software outputs the corresponding optimal prestress And so on... The optimal prestress outputted for each of the above minimum bending moment peaks is: S3.5: Input all the optimal prestresses in S3.4 into the numerical simulation software simultaneously. Corresponding to the optimal prestress applied by anchor cable No. 1, This corresponds to the optimal prestress applied to the anchor cable numbered 2; and so on..., all numbered anchor cables correspond to the optimal prestress applied; The peak bending moment generated by the bored pile at this time is obtained and set as the first optimal bending moment peak, recorded as 3. A multi-row anchor cable prestressing optimization method according to claim 2, characterized in that: Step S4 includes the following steps: S4.1: Set t = 1, L = 2; S4.2: Apply prestress P to the anchor cable numbered k=1 y， L∈{2,3,4,5,…,}, t∈{1,2,3,4,5,…,}; suppose that a total of u prestressing forces are applied, and u changes with the values ​​of L and t; the anchor cables with other numbers maintain the optimal prestressing force; The anchor cable number k=1 is prestressed with P y When the anchor cables with other numbers maintain the optimal prestress, the anchor cable with number k=1 is given the prestress P y The peak bending moment generated by the bored pile is u times; a total of u prestressing forces are applied, and the bored pile generates u peak bending moments, which are recorded as Apply prestress P to the anchor cable numbered k=2 y， L∈{2,3,4,5,…,}, t∈{1,2,3,4,5,…,}; suppose that a total of u prestressing forces are applied, and u changes with the values ​​of L and t; the anchor cables with other numbers maintain the optimal prestressing force; The anchor cable number k=2 is prestressed with P y When the bored pile generates the corresponding bending moment peak, a total of u prestressing forces are applied, and a total of u bending moment peaks are generated by the bored pile, which are recorded as And so on... S4.3: Select the bending moment peak with the smallest absolute value among all the bending moment peaks generated by bored piles in S4.2 and set it as the t+1th optimal bending moment peak, recorded as and obtain The final prestress of each numbered anchor cable corresponding to the following; S4.4: Calculate the optimal bending moment ratio using the formula: S4.5: If ε<5%, it meets the set parameter standard and outputs the value in S4.

3. The final prestress of each numbered anchor cable corresponding to the following; Otherwise, the set parameter standard is not met; if the set parameter standard is not met, then t=t+1 and L=L+1 are substituted into S4.2-S4.5 and the cycle is repeated; assuming: Then the final prestress of each numbered anchor cable under the Vth optimal bending moment peak is output.

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