Quantitative method for steel bracing loading and axial force adjustment of analog servo system

Abstract

The application discloses a steel support loading and axial force adjustment quantitative method of an analog servo system and belongs to the field of deep foundation pit engineering. The method comprises the following steps: under the coherent action of the axial force, the total axial force increment of the servo steel support of the foundation pit supporting structure system is equal to the sum of the product of the single axial force increment of each servo steel support and the corresponding steel support axial force coherent coefficient when the axial force coherent action is not considered. Through the application, the axial loading value of the multiple servo steel supports can be quantified, and the axial force distribution of the servo steel support can meet the target requirement, so that the requirement of different engineering conditions can be flexibly realized.

Description

Technical Field

[0001] This invention relates to the field of deep foundation pit engineering, and in particular to a quantitative method for steel support loading and axial force adjustment in a simulated servo system. Background Technology

[0002] The design of foundation pit support structures plays a crucial role in ensuring the safety of foundation pit construction. Steel bracing, as a common support method for foundation pits, has been widely adopted. However, traditional steel bracing suffers from engineering problems such as flexible head structure conversion and steel wedge deformation, leading to preload loss, unclear axial force patterns, and increased risk of foundation pit structural instability. Steel bracing servo systems achieve high-precision adjustment of axial force through meticulous management, effectively controlling the deformation of foundation pit retaining structures. In hundreds of projects across cities such as Shanghai, Shenzhen, and Nanjing, steel bracing servo systems have demonstrated significant effectiveness in controlling the deformation of deep foundation pit retaining structures, especially in foundation pit engineering in soft soil areas. Nevertheless, the system directly controls the axial force of the bracing, and the understanding of the dynamic adjustment of axial force in the interaction between the bracing, retaining structure, and soil is still insufficient, thus limiting the potential of steel bracing servo systems in preventing and controlling foundation pit deformation.

[0003] In existing steel support servo systems, the servo system automatically activates a compensation mechanism when the axial force is detected to be lower than the preset design value. This automatically adjusts the hydraulic pressure to increase the support axial force, ensuring it does not fall below the target value. Conversely, if the axial force exceeds a warning value, the system triggers an alarm, requiring manual assessment and load reduction. While servo steel supports offer significant advantages in controlling foundation pit deformation, existing technologies lack effective methods to utilize the coherence patterns revealed by servo steel support axial force changes to achieve precise axial force control, thereby improving foundation pit deformation control and optimizing foundation pit engineering deformation management strategies. Summary of the Invention

[0004] To accurately control the axial force variation of steel supports, improve the effectiveness of foundation pit deformation control, and optimize foundation pit engineering deformation management strategies, this invention provides a quantitative method for loading and adjusting the axial force of steel supports in a simulated servo system. This method transforms the overall axial force increment of the steel supports under coherent axial force action into the sum of the products of the individual axial force increments of each servo steel support and their corresponding axial force coherence coefficients, without considering the coherent axial force action. This invention is achieved through the following technical solution.

[0005] This invention introduces a quantitative method for steel support loading and axial force adjustment in a simulated servo system, comprising:

[0006] Based on the design value and measured value of axial force of the servo steel support, the axial force increment matrix of m servo steel supports is calculated when each servo steel support is individually loaded, considering the coherent action of axial force. P T ] m×1 ;

[0007] The axial force coherence coefficient matrix of the servo steel support is obtained based on the axial force increment of any two servo steel supports. x m×m ;

[0008] Based on the axial force increment matrix [ P T ] m×1 and the coherence coefficient matrix of the servo steel support axial force x m×m Solve for the matrix of axial force increments of m servo steel supports when each servo steel support is individually loaded, without considering the coherent effect of axial force. P] m×1 .

[0009] In practical applications, there is significant coherence between the axial forces of the various servo steel supports. During the excavation stage, the axial force of the servo steel supports increases with the excavation depth. During the erection of the next servo steel support, the axial force of adjacent servo steel supports decreases significantly. The cumulative axial force of the servo steel supports drives changes in the axial forces of other servo steel supports. Therefore, in actual calculations, the coherence of the axial forces between the various servo steel supports must be considered. The overall axial force increment of the servo steel supports within the foundation pit support structure system must be converted into the sum of the products of the individual load increment of each servo steel support and the corresponding axial force coherence coefficient, without considering the coherent effect of axial forces. This helps in calculating the required axial force value for the servo steel supports, thereby improving the control effect of axial force changes on foundation pit deformation.

[0010] Optionally, the axial force increment matrix [ P T ] m×1 It is obtained by calculation using the following formula:

[0011] [ P T ] m×1 =[P d ] m×1 -[P t ] m×1 ,

[0012] In the formula, [P d ] m×1 The design value of the axial force for the servo steel support, [P] t ] m×1 The measured axial force value of the servo steel support, [ P T ] m×1 The matrix represents the overall axial force increment of the servo steel support when considering the coherent action of axial force. m represents the total number of servo steel supports, and T is the subscript symbol for the axial force change when considering the coherent action of axial force.

[0013] Optionally, the servo steel support axial force coherence coefficient matrix x m×m The determination includes the following steps:

[0014] S1, Obtain the three-dimensional model of the foundation pit excavation project and determine the geometric model dimensions of the foundation pit to be excavated;

[0015] S2, the excavation depth is H. m The construction simulation calculations were used to determine the number of servo steel supports that need to be installed, where m represents the excavation depth H. m The corresponding number of servo steel support channels that need to be installed;

[0016] S3, apply load to the i-th servo steel support, collect data for the j-th servo steel support, and determine the axial force coherence coefficient ξ of the servo steel support. j,i,m ,

[0017] S4, take j = j-1, collect the axial force of the (j-1)th servo steel support, repeat step S3, and determine the axial force coherence coefficient of the steel support. x j,i,m Until j=1;

[0018] S5, take i = i-1, apply axial loading to the (i-1)th servo steel support, repeat steps S3-S4, and determine the axial force coherence coefficient of the steel support. x j,i,m Until i=1;

[0019] S6, continue excavating the foundation pit to a depth of H. m Repeat steps S2-S5 until m=N, where N is the last servo steel support, and all servo steel supports are installed.

[0020] Optionally, the axial force coherence coefficient matrix of the servo steel support is obtained based on the axial force increment of any two servo steel supports. x m×m This includes: the incremental axial force of the i-th servo steel support. P i,i,m Increment of axial force of the j-th servo steel support P j,i,m The data set is obtained, expressed by the following formula:

[0021] ,in, x j,i,mThe calculation formula is:

[0022] x j,i,m = P j,i,m / P i, i,m ,

[0023] Where, ξ j,i,m The coherence coefficient matrix of the axial force of the servo steel support x m×m , where i is the examination track number for the axial force value of the servo system steel support at the same loading position, and j is the examination track number for the passive change of the axial force of the servo system steel support. P i,i,m The axial force increment of the i-th servo steel support when the i-th servo steel support is loaded. P j,i,m When loading the i-th servo steel support, examine the axial force increment of the j-th servo steel support.

[0024] Optionally, the axial force increment matrix [ P T ] m×1 Servo steel support axial force coherence coefficient matrix x m×m and the axial force increment matrix [ P] m×1 The quantitative relationship among the three is as follows:

[0025] [ P T ] m×1 =[ξ] m×m [ P] m×1 ,

[0026] In the formula, [ P] m×1 For a single servo steel support under load, the matrix of m axial force increments is provided, where the coherent effect of axial force is not considered. P T ] m×1 Let [ξ] be the overall axial force increment matrix of the m-channel servo steel support, considering the coherent effect of the axial force; m×m is the structural coherence coefficient matrix of the servo steel support; m is the total number of servo steel supports.

[0027] Optionally, the axial force increment matrix [ P] m×1 It is obtained by calculation using the following formula:

[0028] [ P] m×1 = [ξ] -1 m×m [ P T ] m×1 ,

[0029] In the formula, [ P] m×1 For a single servo steel support under load, without considering the coherent effect of axial force, the matrix of axial force increment for m-channel servo steel supports; [P d ] m×1 The matrix of axial force design values ​​for servo steel supports, [P t ] m×1 ξ is the matrix of measured axial force values ​​for the servo steel support, and ξ is the coherence coefficient of the axial force of the steel support.

[0030] Optionally, the axial force increment matrix [ P] m×1 It is obtained by calculation using the following formula:

[0031] [ P] m×1 = [ξ] -1 m×m ([P) d ] m×1 -[P t ] m×1 ).

[0032] Optionally, the axial force increment matrix [ P T ] m×1 The specific unfolding format is as follows:

[0033] P j,T,m = x j,1,m P 1,1,m + x j,2,m P 2,2,m +…+ x j,i,m P i,i,m + x j,i+1,m P i+1,i+1,m +…+ x j,m,m Pm,m,m ,

[0034] In the formula, P j,T,m Let ξ be the axial force increment of the j-th servo steel support within the foundation pit structural system, considering the coherent effect of axial force, where j = 1, 2, ..., m, and m is the total number of servo steel supports; j,i,m The coherence coefficient of the axial force of the servo steel support. P i,i,m To ensure the safety of the first section within the foundation pit structural system i When applying axial load to the servo steel support, the first i The axial force increment of the servo steel support is considered without taking into account the coherent effect of the axial force.

[0035] Optionally, the servo steel support axial force coherence coefficient ξ j,i,m The relationship between the change in axial force of the steel support and the change in axial force of the loaded steel support conforms to the elasticity theory and is fitted by a linear equation.

[0036] Beneficial effects:

[0037] (1) This invention further reveals the coherence law of the axial force of steel supports: for a certain excavation depth with multiple servo steel support structures, adding new steel supports will inevitably change the structural system, thereby changing the deformation of the support structure and the axial force value of the supports; in fact, even without adding new servo steel supports, changing the axial force value of the servo steel supports will affect the axial force of other supports. Thus, it is concluded that under the coherent action of axial force, the total axial force increment of each steel support in the foundation pit structure system is equal to the sum of the product of the single axial load increment of each steel support and the corresponding steel support axial force coherence coefficient when the coherent action of axial force is not considered. In practical applications, the coherence law of the axial force of steel supports can be used to simulate the servo system to adjust the axial force value of the steel supports in order to achieve the effect of foundation pit deformation control and optimize the deformation management strategy of foundation pit engineering.

[0038] (2) This invention quantifies the axial force coherence coefficient of a multi-channel steel support structure system. Based on the relationship between the axial force increment of the servo steel support test channel and the axial force increment of the loaded servo steel support test channel in the multi-channel servo steel support structure system, the coherence coefficient of the axial force of the multi-channel support is quantified, the influence range of the support axial force change is clarified, and a quantitative basis is provided for engineering technicians to judge the state of the foundation pit.

[0039] (3) This invention calculates the target increase in axial force difference by combining the design value of the axial force of each servo steel support with the measured axial force value of each servo steel support determined by the construction progress. This invention can then calculate the axial force value applied independently to each servo steel support, perfectly simulating the axial force compensation function of the servo steel support. Therefore, in practical engineering, this method can be used to improve the accuracy of axial force control of steel supports, flexibly meet the needs of different engineering conditions, and improve construction efficiency. Attached Figure Description

[0040] Figure 1 The diagram shown is a schematic representation of the servo steel support structure of the present invention.

[0041] Figure 2 The diagram shown is a flowchart of the method described in this invention;

[0042] Figure 3 The diagram shows the relationship between the axial force increment of the first servo steel support and the axial force increment of the second servo steel support when the second servo steel support is loaded according to the present invention.

[0043] Figure 4 The diagram shows the relationship between the axial force increment of the second servo steel support and the axial force increment of the first servo steel support when the first servo steel support is loaded according to the present invention.

[0044] Figure 5 The diagram shows the relationship between the axial force increments of the first servo steel support and the third servo steel support, as well as the relationship between the axial force increments of the second servo steel support and the third servo steel support when the third servo steel support is loaded according to the present invention.

[0045] Figure 6 The diagram shows the relationship between the axial force increment of the first servo steel support and the axial force increment of the second servo steel support, as well as the relationship between the axial force increment of the third servo steel support and the axial force increment of the second servo steel support when the second servo steel support is loaded according to the present invention.

[0046] Figure 7 The diagram shows the relationship between the axial force increment of the second servo steel support and the axial force increment of the first servo steel support, as well as the relationship between the axial force increment of the third servo steel support and the axial force increment of the first servo steel support when the first servo steel support is loaded according to the present invention.

[0047] In the diagram: 1-steel support, 2-support hinge head, 3-ultrasonic rangefinder, 4-hydraulic cylinder, 5-hydraulic cylinder stroke. Detailed Implementation

[0048] The following description, in conjunction with the accompanying drawings and specific embodiments, provides further details. In this description, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0049] Example 1

[0050] This embodiment introduces a quantitative method for steel support loading and axial force adjustment in a simulated servo system, including the following:

[0051] Based on the design value and measured value of axial force of the servo steel support, the axial force increment matrix of m servo steel supports is calculated when each servo steel support is individually loaded, considering the coherent action of axial force. P T ] m×1 ;

[0052] The axial force coherence coefficient matrix of the servo steel support is obtained based on the axial force increment of any two servo steel supports. x m×m ;

[0053] Based on the axial force increment matrix [ P T ] m×1 and the coherence coefficient matrix of the servo steel support axial force x m×m Solve for the matrix of axial force increments of m servo steel supports when each servo steel support is individually loaded, without considering the coherent effect of axial force. P] m×1 .

[0054] like Figure 1 The diagram shows a schematic of the servo system support head. The steel support 1, driven by the servo system, is connected to the movable support head 2 via a hydraulic cylinder 4, controlling the extension and retraction of the jack to achieve dynamic adjustment of the axial force. The sensors and ultrasonic rangefinder 3 embedded in the support head can monitor the axial force and hydraulic cylinder stroke 5 in real time, and feed the data back to the central control center for analysis and storage. In practical applications, the central control center is used to execute the quantitative method for steel support loading and axial force adjustment of the simulated servo system in this embodiment of the invention.

[0055] In practical applications, there is significant coherence between the axial forces of the various servo steel supports. During the excavation stage, the axial force of the servo steel supports increases with the excavation depth. During the erection of the next servo steel support, the axial force of adjacent servo steel supports decreases significantly. The cumulative axial force of the servo steel supports drives changes in the axial forces of other servo steel supports. Therefore, in actual calculations, the coherence of the axial forces between the various servo steel supports must be considered. The overall axial force increment of the servo steel supports within the foundation pit support structure system must be converted into the sum of the products of the individual load increment of each servo steel support and the corresponding axial force coherence coefficient, without considering the coherent effect of axial forces. This helps in calculating the required axial force value for the servo steel supports, thereby improving the control effect of axial force changes on foundation pit deformation.

[0056] Example 2

[0057] Based on Example 1, this example introduces the specific implementation process of a quantitative method for steel support loading and axial force adjustment in a simulated servo system, specifically including the following:

[0058] Table 1 below shows the material parameters of the foundation pit retaining structure for the main structure of a certain station. The standard section has six vertical supports; from top to bottom, the first support is concrete, and the first to fifth supports are servo steel supports.

[0059]

[0060] like Figure 2 The following steps are shown in this embodiment for calculating the coherence coefficient of the servo steel support axial force:

[0061] S1, Obtain the three-dimensional model of the foundation pit excavation project and determine the geometric model dimensions of the foundation pit to be excavated;

[0062] S2, the excavation depth is H. m The construction simulation calculations were used to determine the number of servo steel supports that need to be installed, where m represents the excavation depth H. m The corresponding number of servo steel support channels that need to be installed;

[0063] S3, apply load to the i-th servo steel support, collect data for the j-th servo steel support, and determine the axial force coherence coefficient ξ of the servo steel support. j,i,m ,

[0064] S4, take j = j-1, collect the axial force of the (j-1)th servo steel support, repeat step S3, and determine the axial force coherence coefficient of the steel support. x j,i,m Until j=1;

[0065] S5, take i = i-1, apply axial loading to the (i-1)th servo steel support, repeat steps S3-S4, and determine the axial force coherence coefficient of the steel support. xj,i,m Until i=1;

[0066] S6, continue excavating the foundation pit to a depth of H. m Repeat steps S2-S5 until m=N, where N is the last servo steel support, and all servo steel supports are installed.

[0067] During actual excavation of the foundation pit, when the excavation depth is 10.8 meters, two servo steel supports need to be erected, combined with... Figure 3-Figure 4 It can be seen that, x 1,2,2 = P 1,2,2 / P 2,2,2 =-0.81, x 2,1,2 = P 2,1,2 / P 1,1,2 =-0.63, axial force self-coherence coefficient x 1,1,2 = x 2,2,2 =1. At this time, the servo steel support coherence coefficient matrix [ x ] 2×2 for:

[0068] .

[0069] When the excavation depth of the foundation pit is 13.8 meters, three servo steel supports need to be erected, combined with... Figure 5-Figure 7 It can be seen that, x 1,2,3 = P 1,2,3 / P 2,2,3 =-0.56, x 1,3,3 = P 1,3,3 / P 3,3,3 =-0.10, x 2,1,3 = P 2,1,3 / P 1,1, 3 =-0.57, x 2,3,3 = P 2,3,3 / P 3,3,3 =-0.77, x 3,1,3 = P 3,1,3 / P 1,1,3 =-0.08, x 3,2,3 = P 3,2,3 / P 2,2,3 =-0.44, axial force self-coherence coefficient x 1,1,2 = x 2,2,2 = x 3,3,3 =1. At this time, the servo steel support coherence coefficient matrix [ x ] 3×3 for:

[0070] .

[0071] In practical engineering, there is coherence among the axial forces of servo steel supports. Under the influence of axial force coherence, the overall axial force increment of the j-th servo steel support in the foundation pit support structure system is... P j,T,m This is equal to the sum of the products of the individual axial force increment of each servo steel support and the corresponding axial force coherence coefficient of the servo steel support, without considering axial force coherence, where j = 1, 2, ..., m, and m is the total number of servo steel supports. P j,T,m The calculation formula is as follows:

[0072] P j,T,m = x j,1,m P 1,1,m + x j,2,m P 2,2,m +…+ x j,i,m P i,i,m + x j,i+1,m P i+1,i+1,m +…+ x j,m,m P m,m,m ,

[0073] In the formula, P j,T,m The total axial force increment of the j-th servo steel support when considering the influence of axial force coherence within the foundation pit structure system; P i,m The axial force increment of the i-th servo steel support when an axial load is applied to the i-th servo steel support within the foundation pit structure system without considering the influence of coherence.

[0074] Written in matrix form, that is: [ P T ] m×1 =[ξ] m´m [ P] m×1 ,

[0075] In this embodiment, j=1, 2, 3; i=1, 2, 3; m=3, which is [ P T ] 3×1 =[ξ] 3×3 [ P] 3×1 :

[0076] P 1,T,m = x 1,1,3 P 1,1,3 + x 1,2,3 P 2,2,3 + x 1,3,3 P 3,3,3 ,

[0077] P 2,T,m = x 2,1,3 P 1,1,3 + x 2,2,3 P 2,2,3 + x 2,3,3 P 3,3,3 ,

[0078] P 3,T,m = x 3,1,3 P 1,1,3 + x 3,2,3 P 2,2,3 + x 3,3,3 P 3,3,3 ,

[0079] Will Substituting, we get:

[0080] ,

[0081] Before the fourth servo steel support was installed and loaded, the axial forces of the second, third, and fourth servo steel supports were measured. The measured values ​​were 1653.7 kN, 2102.4 kN, and 0 kN, respectively, denoted as matrix [P]. t ] 3×1 After the fourth servo steel support is installed and loaded, the target axial force values ​​for the second, third, and fourth servo steel supports are designed to be 1600kN, 1700kN, and 2100kN, respectively, denoted as matrix [P]. d ] 3×1 At this point, the influence of axial force coherence is considered. Therefore, the required axial force increment for the servo steel support is:

[0082] ,

[0083] Right now ,

[0084] Solving the equations, we obtain the axial force increment of each servo steel support after installing the fourth servo steel support, neglecting the influence of coherence:

[0085] .

[0086] Therefore, in this embodiment, after the fourth servo steel support is installed and loaded, in order to meet the target axial force design values ​​of 1600kN, 1700kN, and 2100kN for the second, third, and fourth servo steel supports, respectively, it is necessary to load the second, third, and fourth servo steel supports so that their axial forces increase by 3050.39kN, 4751.31kN, and 4434.74kN respectively without considering the influence of axial force coherence.

[0087] In actual engineering, the axial forces between servo steel supports exhibit coherence, and the overall increase in axial force of the servo steel supports within the foundation pit support structure system […]. P T ] m×1 This is equal to the sum of the products of the individual axial load increment of each servo steel support and its corresponding load conversion factor, without considering the influence of axial force coherence, where j = 1, 2, ..., m, and m is the total number of servo steel supports. P T ] m×1 The calculation formula is as follows:

[0088] [ P T ] m×1 =[ or ] m×m [ N] m×1 ,

[0089] In the formula, [ P T ] m×1 The axial force increment matrix for the servo steel support; or ] m×m For the load conversion factor matrix of the servo steel support; [ N] m×1 Let m be the matrix representing the incremental axial load applied to the servo steel supports; expanding the matrix above, we get:

[0090] ,

[0091] In the formula, or j,i,m This is the load conversion factor of the axial force of the j-th servo steel support when the i-th servo steel support is loaded; P j,i,m This refers to the axial force increment of the j-th servo steel support when the i-th servo steel support is loaded; Ni,m Let be the load increment after loading the i-th servo steel support; the above formula is transformed as follows:

[0092] ,

[0093] because x j,i,m = P j,i,m / P i,i,m , P i,i,m = or i,i,m N i,m , P j,i,m = or j,i,m N i,m ,so x j,i,m = P j,i,m / P i,i,m =h j,i,m N i,m / or i,i,m N i,m = or j,i,m / or i,i,m In the formula, P i,i,m = or i,i,m N i,m This indicates that when the i-th servo steel support is loaded, the axial force increment of the i-th support is equal to the product of the load increment and the corresponding load conversion coefficient. In this case, the influence of axial force coherence is not considered. x j,i,m = indicates that when the first... i When the servo-driven steel supports are loaded, the coherence coefficient of the axial force of the i-th support to the j-th support is equal to the ratio of the load conversion coefficient of the axial force of the j-th support to the load conversion coefficient of the axial force of the i-th support. That is:

[0094] ,

[0095] Right now: .

[0096] In this embodiment, specific data is used to verify that, without considering the coherence effect of the axial forces between the various servo steel supports, the comprehensive increment of the axial force of the servo steel supports in the foundation pit support structure system is the sum of the product of the load increment of each servo steel support and its corresponding load conversion coefficient.

[0097] Through experiments, when the excavation depth of the foundation pit is 13.8 meters, the load conversion factor matrix is:

[0098] Substitute the load transformation coefficient matrix into the equation

[0099] In the middle, get

[0100] ,

[0101] Transform it into a coherence coefficient matrix, that is: ,

[0102] The axial force increment of each servo steel support after loading, without considering the influence of coherence, is as follows: The unit is kN.

[0103] again[ P T ] m×1 =[ or ] m×m [ N] m×1 ,so:

[0104] ,

[0105] The axial load increment of each servo steel support after loading, without considering the influence of coherence, is as follows:

[0106] The unit is kN.

[0107] Right now:

[0108] 3050.39kN = 0.4407 × 6921.7kN

[0109] 4751.31kN = 0.5605 × 8476.9kN

[0110] 4434.74kN=0.3092×14342.6kN.

[0111] Therefore, without considering the influence of the axial force coherence between the servo steel supports, the axial force increment of each servo steel support is the sum of the product of the axial load increment of each servo steel support and its corresponding load conversion coefficient.

[0112] In practical applications, for this implementation case, axial loads of 6921.7kN, 8476.9kN, and 14342.6kN need to be applied to the first, second, and third servo steel supports, respectively, to increase their axial forces by 3050.39kN, 4751.31kN, and 4434.74kN, respectively, in order to meet the design values ​​of 1600kN, 1700kN, and 2100kN for the axial forces of the first, second, and third servo steel supports, respectively.

[0113] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A quantitative method for loading and adjusting axial force of steel supports in a simulated servo system, characterized in that, Based on the design value and measured value of axial force of the servo steel support, the axial force increment matrix of m servo steel supports is calculated when each servo steel support is individually loaded, considering the coherent action of axial force. P T ] m×1 ; The axial force coherence coefficient matrix of the servo steel support is obtained based on the axial force increment of any two servo steel supports. ξ m×m ; Based on the axial force increment matrix [ P T ] m×1 and the coherence coefficient matrix of the servo steel support axial force ξ m×m Solve for the matrix of axial force increments of m servo steel supports when each servo steel support is individually loaded, without considering the coherent effect of axial forces. P] m×1； The axial force increment matrix [ P T ] m×1 It is obtained by calculation using the following formula: [ P T ] m×1 =[P d ] m×1 -[P t ] m×1 , In the formula, [P d ] m×1 The design value of the axial force for the servo steel support, [P] t ] m×1 The measured axial force value of the servo steel support, [ P T ] m×1 The matrix represents the overall axial force increment of the servo steel support when considering the coherent action of axial force, where m is the total number of servo steel supports and T is the subscript symbol for the axial force change when considering the coherent action of axial force. The servo steel support axial force coherence coefficient matrix ξ m×m The determination includes the following steps: S1, Obtain the three-dimensional model of the foundation pit excavation project and determine the geometric model dimensions of the foundation pit to be excavated; S2, the excavation depth is H. m The construction simulation calculations were used to determine the number of servo steel supports that need to be installed, where m represents the excavation depth H. m The corresponding number of servo steel support channels that need to be installed; S3, apply load to the i-th servo steel support, collect data for the j-th servo steel support, and determine the axial force coherence coefficient ξ of the servo steel support. j,i,m , S4, take j = j-1, collect the axial force of the (j-1)th servo steel support, repeat step S3, and determine the axial force coherence coefficient of the steel support. ξ j,i,m Until j=1; S5, take i = i-1, apply axial loading to the (i-1)th servo steel support, repeat steps S3-S4, and determine the axial force coherence coefficient of the steel support. ξ j,i,m Until i=1; S6, continue excavating the foundation pit to a depth of H. m Repeat steps S2-S5 until m=N, where N is the last servo steel support, and all servo steel supports are installed. The axial force increment matrix [ P] m×1 It is obtained by calculation using the following formula: [ P] m×1 = [ξ] -1 m×m [ P T ] m×1 , In the formula, [ P] m×1 For a single servo steel support under load, without considering the coherent effect of axial force, the matrix of axial force increment for m-channel servo steel supports; [P d ] m×1 The matrix of axial force design values ​​for servo steel supports, [P t ] m×1 ξ is the matrix of measured axial force values ​​for the servo steel support, and ξ is the coherence coefficient of the axial force of the steel support.

2. The method according to claim 1, characterized in that, The axial force coherence coefficient matrix of the servo steel support is obtained based on the axial force increment of any two servo steel supports. ξ m×m This includes: the incremental axial force of the i-th servo steel support. P i,i,m Increment of axial force of the j-th servo steel support P j,i,m The data set is obtained, expressed by the following formula: ,in, ξ j,i,m The calculation formula is: ξ j,i,m = P j,i,m / P i, i,m ， Where, ξ j,i,m For the servo steel support axial force coherence coefficient matrix ξ m×m , where i is the examination track number for the axial force value of the servo system steel support at the same loading position, and j is the examination track number for the passive change of the axial force of the servo system steel support. P i,i,m The axial force increment of the i-th servo steel support when the i-th servo steel support is loaded. P j,i,m When loading the i-th servo steel support, examine the axial force increment of the j-th servo steel support.

3. The method according to claim 1, characterized in that, The axial force increment matrix [ P T ] m×1 Servo steel support axial force coherence coefficient matrix ξ m×m and the axial force increment matrix [ P] m×1 The quantitative relationship among the three is as follows: [ P T ] m×1 =[ξ] m×m [ P] m×1 , In the formula, [ P] m×1 For a single servo steel support under load, the matrix of m axial force increments is provided, where the coherent effect of axial force is not considered. P T ] m×1 Let [ξ] be the overall axial force increment matrix of the m-channel servo steel support, considering the coherent effect of the axial force; m×m is the structural coherence coefficient matrix of the servo steel support; m is the total number of servo steel supports.

4. The method according to claim 1, characterized in that, The axial force increment matrix [ P] m×1 It is obtained by calculation using the following formula: [ P] m×1 = [ξ] -1 m×m ([P d ] m×1 -[P t ] m×1 ).

5. The method according to claim 3, characterized in that, The axial force increment matrix [ P T ] m×1 The specific unfolding format is as follows: P j,T,m = ξ j,1,m P 1,1,m + ξ j,2,m P 2,2,m +…+ ξ j,i,m P i,i,m + ξ j,i+1,m P i+1,i+1,m +…+ ξ j,m,m P m,m,m ， In the formula, ∆ P j,T,m Let ξ be the axial force increment of the j-th servo steel support within the foundation pit structural system, considering the coherent effect of axial force, where j = 1, 2, ..., m, and m is the total number of servo steel supports; j,i,m The coherence coefficient of the axial force of the servo steel support. P i,i,m In order to protect the first within the foundation pit structural system i When applying axial load to the servo steel support, the first i The axial force increment of the servo steel support is considered without taking into account the coherent effect of the axial force.

6. The method according to any one of claims 1 or 2, characterized in that, The servo steel support axial force coherence coefficient ξ j,i,m The relationship between the change in axial force of the steel support and the change in axial force of the loaded steel support conforms to the elasticity theory and is fitted by a linear equation.

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