Steel support loading and axial force adjustment quantitative method for simulating servo system

Abstract

The invention discloses a steel support loading and axial force adjustment quantitative method for simulating a servo system, and belongs to the field of deep foundation pit engineering. The method comprises the steps that under the action of axial force coherence, the total axial force increment of servo steel supports of a 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 axial force coherence coefficient of the corresponding steel support when the axial force coherence action is not considered; by means of the method, the axial loading quantity values of multiple servo steel supports can be quantized, then the axial force distribution of the servo steel supports meets the target requirement, and the requirements of different engineering conditions are flexibly met.

Description

Technical Field

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

[0002] The design of foundation pit support structure plays a key role in ensuring the safety of foundation pit construction. As a common support scheme in foundation pits, steel support has been widely adopted. However, traditional steel supports have engineering problems such as active head structure conversion and steel wedge deformation, which lead to loss of preloaded axial force, unclear axial force law, and increase the risk of instability of foundation pit structure. The steel support servo system achieves high-precision adjustment of axial force through fine management, thereby effectively controlling the deformation of foundation pit retaining structure. In hundreds of projects in Shanghai, Shenzhen, Nanjing and other cities, the steel support servo system has shown significant effects in the deformation control of deep foundation pit retaining structure, especially in foundation pit projects in soft soil areas. Nevertheless, the direct control object of the system is the support axial force, and the understanding of the dynamic adjustment of the axial force of the interaction between support, retaining structure and soil is still insufficient, which limits the potential of the steel support servo system in preventing and controlling foundation pit deformation.

[0003] In the existing steel support servo system technology, the servo system can automatically start the compensation mechanism according to the preset axial force design value when the axial force is detected to be lower than the design value, and then automatically adjust the oil pressure to increase the support axial force so that the axial force is not lower than the target axial force value; on the contrary, if the axial force exceeds the warning value, the system will trigger an alarm, and manual evaluation is required to reduce the load. Servo steel support has a significant effect on foundation pit deformation control. Compared with the problems of ordinary steel support, how to use the coherence law revealed by the axial force change of servo steel support to achieve precise control of axial force, so as to improve the effect of foundation pit deformation control, and then optimize the deformation management strategy of foundation pit engineering, there is still a lack of effective means in the existing technology. Summary of the invention

[0004] In order to accurately control the change of steel support axial force, improve the effect of foundation pit deformation control, and optimize the deformation management strategy of foundation pit engineering, the present invention provides a quantitative method for adjusting the steel support loading and axial force of a simulated servo system, by converting the overall axial force increment of the steel support under the coherent action of the axial force into the sum of the product of the single axial force increment of each servo steel support and its corresponding axial force coherence coefficient when the coherent action of the axial force is not considered. The present invention is achieved through the following technical solutions.

[0005] The present invention introduces a quantitative method for adjusting steel support loading and axial force of a simulated servo system, comprising: Based on the design value of the axial force of the servo steel support and the measured value of the axial force of the servo steel support, the axial force increment matrix [ P T ] m×1 ; Obtain the axial force coherence coefficient matrix of the servo steel support based on the axial force increments of any two servo steel supports x m×m ; Based on the axial force increment matrix [ P T ] m×1 and the servo steel support axial force coherence coefficient matrix x m×m Solve the incremental matrix of the axial force of m servo steel supports when each servo steel support is loaded separately without considering the coherent effect of the axial force [ P] m×1 .

[0006] In actual application, there is significant coherence between the axial forces of each servo steel support. The axial force of the servo steel support in the foundation pit excavation stage increases with the excavation depth. The axial force of the adjacent servo steel support will be significantly reduced during the erection of the next servo steel support. The complex axial force of the servo steel support will drive the change of the axial force of other servo steel supports. Therefore, in actual calculations, it is necessary to consider the coherence of the axial forces between each servo steel support, and convert the overall axial force increment of the servo steel support in the foundation pit support structure system into the sum of the product of the single load increment of each servo steel support and the corresponding steel support axial force coherence coefficient when the axial force coherence effect is not considered. It helps to calculate the axial force value required by the servo steel support to improve the control effect of the axial force change on the foundation pit deformation.

[0007] Optionally, the axial force increment matrix [ P T ] m×1 Calculated by the following formula: [ P T ] m×1 =[P d ] m×1 -[P t ] m×1 , In the formula, [P d ] m×1 is the axial force design value of the servo steel support, [P t ] m×1 is the measured value of the axial force of the servo steel support, [ P T ] m×1is the total axial force increment matrix of the servo steel support when the axial force coherence is considered, m is the total number of servo steel supports, and T is the subscript symbol of the axial force variation considering the axial force coherence.

[0008] Optionally, the servo steel support axial force coherence coefficient matrix x m×m The determination includes the following steps: S1, obtaining a three-dimensional model of the foundation pit excavation project and determining the geometric model size of the foundation pit to be excavated; S2, the excavation depth is H m The construction simulation calculation is 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 tracks that need to be installed; S3, load the i-th servo steel support, collect data from the j-th servo steel support, and determine the servo steel support axial force coherence coefficient ξ j,i,m , S4, take j = j-1, collect the axial force of the j-1th servo steel support, repeat step S3, and determine the coherence coefficient of the axial force of the steel support x j,i,m ; Until j=1; S5, take i = i-1, axially load the i-1th servo steel support, repeat steps S3-S4, and determine the steel support axial force coherence coefficient x j,i,m ; Until i=1; S6, continue to excavate the foundation pit to a depth of H m , repeat steps S2-S5 until m=N, N is the last servo steel support, and all servo steel supports are erected.

[0009] Optionally, the axial force coherence coefficient matrix of the servo steel support is obtained based on the axial force increments of any two servo steel supports. x m×m , including: axial force increment through the i-th servo steel support P i,i,m The axial force increment of the jth servo steel support P j,i,m The data set is obtained, and the expression formula is: ,in, x j,i,m The calculation formula is: x j,i,m = P j,i,m / Pi, i,m , Among them, ξ j,i,m is the servo steel support axial force coherence coefficient matrix x m×m , i is the inspection track number of the servo system steel support with the same axial force value as the loading position, j is the inspection track number of the servo system steel support with passive axial force change, P i,i,m is the axial force increment of the i-th servo steel support when loading the i-th servo steel support, P j,i,m When loading the i-th servo steel support, the axial force increment of the j-th servo steel support is investigated.

[0010] 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 equivalent relationship between the three is: [ P T ] m×1 =[ξ] m×m [ P] m×1 , In the formula, [ P] m×1 is the axial force increment matrix of the m-channel servo steel support when the servo steel support is loaded individually, and the axial force coherence effect is not considered at this time; [ P T ] m×1 is the total axial force increment matrix of the m-channel servo steel support, and the axial force coherence effect is considered at this time; [ξ] m×m is the structural coherence coefficient matrix of the servo steel support; m is the total number of servo steel supports.

[0011] Optionally, the axial force increment matrix [ P] m×1 Calculated by the following formula: [ P] m×1 = [ξ] -1 m×m [ P T ] m×1 , In the formula, [ P] m×1 is the axial force increment matrix of the m-channel servo steel support when the servo steel support is loaded individually without considering the coherent effect of the axial force; [P d ]m×1 is the axial force design value matrix of the servo steel support, [P t ] m×1 is the measured value matrix of the axial force of the servo steel support, and ξ is the coherence coefficient of the axial force of the steel support.

[0012] Optionally, the axial force increment matrix [ P] m×1 Calculated by the following formula: [ P] m×1 = [ξ] -1 m×m ([P d ] m×1 -[P t ] m×1 ).

[0013] Optionally, the axial force increment matrix [ P T ] m×1 The specific expansion form is as follows: 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 , In the formula, P j,T,m is the axial force increment of the jth servo steel support in the foundation pit structure system. At this time, the coherent effect of the axial force is considered, where j = 1, 2, …, m, and m is the total number of servo steel supports; ξ j,i,m is the servo steel support axial force coherence coefficient, P i,i,m In order to i The axial load applied to the servo steel support isi The axial force increment of the servo steel support is calculated, and the axial force coherence effect is not considered at this time.

[0014] Optionally, the servo steel support axial force coherence coefficient ξ j,i,m It reflects that the relationship between the change in the axial force of the examined steel support and the change in the axial force of the loaded steel support is consistent with the elastic theory and is fitted using a linear equation.

[0015] Beneficial effects: (1) The present invention further reveals the coherence law of the axial force of steel supports: for a certain excavation depth and the presence of multiple servo steel support structures, the addition of new steel supports will inevitably change the structural system, thereby changing the deformation of the supporting structure and the support axial force value; in fact, even if there are no new servo steel supports, changing the servo steel support axial force value will also affect the axial force of other supports. It can be concluded that under the coherent effect of axial force, the overall axial force increment of each steel support in the foundation pit structure system is equal to the sum of the products of the single axial load increment of each steel support and the corresponding steel support axial force coherence coefficient when the axial force coherence effect 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 steel supports, so as to achieve the effect of foundation pit deformation control and optimize the deformation management strategy of foundation pit engineering.

[0016] (2) The present invention quantifies the axial force coherence coefficient of the multi-channel steel support structure system. According to the relationship between the axial force increment of the servo steel support inspection channel and the axial force increment of the loading servo steel support inspection channel of the multi-channel servo steel support structure system, the coherence coefficient of the multi-channel support axial force is quantified, and the influence range of the support axial force change is clarified, providing a quantitative basis for engineering and technical personnel to judge the state of the foundation pit.

[0017] (3) The present invention calculates the target increased axial force difference value for the axial force design value of each servo steel support and the measured axial force value of each servo steel support determined by the construction progress. The present invention can calculate the axial force value independently applied by each servo steel support, and perfectly simulates the axial force compensation function of the servo steel support. Therefore, in actual engineering, this method can be used to improve the precision control capability of the axial force of the steel support, flexibly meet the needs of different engineering conditions, and improve construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The figure shows a schematic diagram of the composition of the servo steel support structure of the present invention; Figure 2 Shown is a flow chart of the method of the present invention; Figure 3 It is a schematic diagram showing 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; Figure 4It is a schematic diagram showing 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; Figure 5 It is a schematic diagram showing the relationship between the axial force increment of the first servo steel support and the axial force increment of the third servo steel support, and the relationship between the axial force increment of the second servo steel support and the axial force increment of the third servo steel support when the third servo steel support is loaded according to the present invention; Figure 6 It is a schematic diagram showing the relationship between the axial force increment of the first servo steel support and the axial force increment of the second servo steel support, and 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; Figure 7 It is a schematic diagram showing the relationship between the axial force increment of the second servo steel support and the axial force increment of the first servo steel support, and 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; In the figure: 1- steel support, 2- support movable head, 3- ultrasonic rangefinder, 4- oil cylinder, 5- oil cylinder stroke. DETAILED DESCRIPTION

[0019] The following is a further description in conjunction with the accompanying drawings and specific embodiments. In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. Example

[0020] This embodiment introduces a quantitative method for adjusting the steel support loading and axial force of a simulated servo system, including the following contents: Based on the design value of the axial force of the servo steel support and the measured value of the axial force of the servo steel support, the axial force increment matrix [ P T ] m×1 ; Obtain the axial force coherence coefficient matrix of the servo steel support based on the axial force increments of any two servo steel supports x m×m ; Based on the axial force increment matrix [ P T ] m×1 and the servo steel support axial force coherence coefficient matrix x m×mSolve the incremental matrix of the axial force of m servo steel supports when each servo steel support is loaded separately without considering the coherent effect of the axial force [ P] m×1 .

[0021] like Figure 1 The figure shows a schematic diagram of the servo system support head. The steel support 1 servo system is connected to the support head 2 through the oil cylinder 4 to control the telescopic action of the jack and realize the dynamic adjustment of the axial force. The sensor and ultrasonic rangefinder 3 embedded in the support head can monitor the axial force and the oil cylinder stroke 5 in real time, and feed the data back to the central control center for analysis and storage. In actual application, the central control center is used to execute the quantitative method of steel support loading and axial force adjustment of the simulated servo system in the embodiment of the present invention.

[0022] In actual application, there is significant coherence between the axial forces of each servo steel support. The axial force of the servo steel support in the foundation pit excavation stage increases with the excavation depth. The axial force of the adjacent servo steel support will be significantly reduced during the erection of the next servo steel support. The complex axial force of the servo steel support will drive the change of the axial force of other servo steel supports. Therefore, in actual calculations, it is necessary to consider the coherence of the axial forces between each servo steel support, and convert the overall axial force increment of the servo steel support in the foundation pit support structure system into the sum of the product of the single load increment of each servo steel support and the corresponding steel support axial force coherence coefficient when the axial force coherence effect is not considered. It helps to calculate the axial force value required by the servo steel support to improve the control effect of the axial force change on the foundation pit deformation. Example

[0023] Based on Example 1, this example introduces a specific implementation process of a quantitative method for adjusting steel support loading and axial force of a simulated servo system, which specifically includes the following contents: Table 1 below shows the material parameters of the foundation pit retaining structure for the main structure of a station. Six supports are set vertically in the standard section. From top to bottom, the first one is a concrete support, and the first to fifth ones are servo steel supports.

[0024]

[0025] like Figure 2 The steps for calculating the servo steel support axial force coherence coefficient in this embodiment are shown as follows: S1, obtaining a three-dimensional model of the foundation pit excavation project and determining the geometric model size of the foundation pit to be excavated; S2, the excavation depth is H m The construction simulation calculation is 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 tracks that need to be installed; S3, load the i-th servo steel support, collect data from the j-th servo steel support, and determine the servo steel support axial force coherence coefficient ξ j,i,m , S4, take j = j-1, collect the axial force of the j-1th servo steel support, repeat step S3, and determine the coherence coefficient of the axial force of the steel support x j,i,m ; Until j=1; S5, take i = i-1, axially load the i-1th servo steel support, repeat steps S3-S4, and determine the steel support axial force coherence coefficient x j,i,m ; Until i=1; S6, continue to excavate the foundation pit to a depth of H m , repeat steps S2-S5 until m=N, N is the last servo steel support, and all servo steel supports are erected.

[0026] When the excavation depth of the foundation pit is 10.8 meters, two servo steel supports need to be erected. 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: .

[0027] When the excavation depth of the foundation pit is 13.8 meters, three servo steel supports need to be erected. Figure 5-Figure 7 It can be seen that x 1,2,3 = P 1,2,3 / P 2,2,3 =-0.56, x1,3,3 = 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: .

[0028] In actual engineering, there is coherence between the axial forces of the servo steel supports. Under the influence of the axial force coherence, the overall axial force increment of the jth servo steel support of the foundation pit support structure system is P j,T,m It is equal to the sum of the products of the single axial force increment of each servo steel support and the axial force coherence coefficient of the corresponding servo steel support when the axial force coherence is not considered, where j=1, 2, ..., m, m is the total number of servo steel supports, Pj,T,m The calculation formula is as follows: 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 , In the formula, P j,T,m is the total axial force increment of the jth servo steel support when the influence of axial force coherence is considered in the foundation pit structure system; P i,m is the axial force increment of the i-th servo steel support when the axial load is applied to the i-th servo steel support without considering the coherence effect in the foundation pit structure system; Written in matrix form, that is: P T ] m×1 =[ξ] m´m [ P] m×1 , In this embodiment, j=1, 2, 3; i=1, 2, 3; m=3, that is, [ P T ] 3×1 =[ξ] 3×3 [ P] 3×1 : P 1,T,m = x 1,1,3 P 1,1,3 + x 1,2,3 P2,2,3 + x 1,3,3 P 3,3,3 , 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 , 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 , Will Substituting in, we get: , Before the fourth servo steel support was loaded, the axial forces of the second, third and fourth servo steel supports were measured, and the measured values ​​were 1653.7 kN, 2102.4 kN and 0 kN, respectively, recorded as matrix [P t ] 3×1 After the fourth servo steel support is loaded, the target axial forces of the second, third and fourth servo steel supports are designed to be 1600 kN, 1700 kN and 2100 kN respectively, which are recorded as the matrix [P d ] 3×1 At this time, the influence of axial force coherence is considered. Then the axial force increment required by the servo steel support is: , Right now , Solving the equation, we can get that the axial force increment of each servo steel support after the fourth servo steel support is installed and loaded without considering the coherence effect is: .

[0029] Therefore, in this embodiment, after the fourth servo steel support is erected and loaded, in order to meet the requirements that the target axial force design values ​​of the second, third and fourth servo steel supports are 1600kN, 1700kN, and 2100kN respectively, it is necessary to load the second, third and fourth servo steel supports so that their axial forces are increased by 3050.39kN, 4751.31kN and 4434.74kN respectively without considering the influence of axial force coherence.

[0030] In actual engineering, the axial forces between the servo steel supports are coherent, and the comprehensive increment of the axial forces of the servo steel supports in the foundation pit support structure system [ P T ] m×1 is equal to the sum of the products of the single axial load increment of each servo steel support and its corresponding load conversion coefficient when the influence of axial force coherence is not considered, where j = 1, 2, ..., m, m is the total number of servo steel supports, [ P T ] m×1 The calculation formula is as follows:

[0031] [ P T ] m×1 =[ or ] m×m [ N] m×1 , In the formula, [ P T ] m×1 is the axial force increment matrix of the servo steel support; [ or ] m×m is the load conversion factor matrix of the servo steel support; [ N] m×1 is the incremental matrix of the applied axial load of the servo steel support, and m represents the number of servo steel supports; the above matrix is ​​expanded into: , In the formula, or j,i,m is the load conversion coefficient of the axial force of the jth servo steel support when the i-th servo steel support is loaded; P j,i,m is the axial force increment of the jth servo steel support when the i-th servo steel support is loaded; Ni,m is the load increment after the i-th servo steel support is loaded; the above formula is transformed into: , 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 , where P i,i,m = or i,i,m N i,m It means 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. At this time, the influence of axial force coherence is not considered. x j,i,m = indicates that when i When the servo steel support is 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: , Right now: .

[0032] In this embodiment, specific data is brought in to verify that when the coherence effect of the axial forces between the servo steel supports is not considered, the comprehensive increment of the axial forces of the servo steel supports in the foundation pit support structure system is the sum of the products of the load increments of each servo steel support and their corresponding load conversion coefficients.

[0033] Through experiments, when the excavation depth of the foundation pit is 13.8 meters, the load conversion coefficient matrix is: , substitute the load conversion coefficient matrix into the equation In , Transformed into a coherence coefficient matrix, namely: , The axial force increment of each servo steel support after loading without considering the coherence effect is: , unit is kN, again[ P T ] m×1 =[ or ] m×m [ N] m×1 ,so: , The axial load increment of each servo steel support after loading without considering the coherence effect is obtained as: , unit is kN, Right now: 3050.39kN=0.4407×6921.7kN, 4751.31kN=0.5605×8476.9kN, 4434.74kN=0.3092×14342.6kN.

[0034] It can be seen that when the influence of the axial force coherence between the servo steel supports is not considered, the axial force increment of each servo steel support is the sum of the products of the axial load increment of each servo steel support and its corresponding load conversion coefficient.

[0035] In actual application, for this implementation case, the first, second and third servo steel supports need to be loaded with axial loads of 6921.7 kN, 8476.9 kN and 14342.6 kN respectively, so that their axial forces are increased by 3050.39 kN, 4751.31 kN and 4434.74 kN respectively, in order to meet the requirements that the design values ​​of the axial forces of the first, second and third servo steel supports are 1600 kN, 1700 kN and 2100 kN respectively.

[0036] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the enlightenment of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which all fall within the protection of the present invention.

Claims

1. A quantitative method for adjusting steel support loading and axial force of a simulated servo system, characterized in that: Based on the design value of the axial force of the servo steel support and the measured value of the axial force of the servo steel support, the axial force increment matrix [ P T ] m×1 ; Obtain the servo steel support axial force coherence coefficient matrix based on the axial force increments of any two servo steel supports ξ m×m ; Based on the axial force increment matrix [ P T ] m×1 and the servo steel support axial force coherence coefficient matrix ξ m×m Solve the incremental matrix of the axial force of m servo steel supports when each servo steel support is loaded separately without considering the coherent effect of the axial force [ P] m×1 .

2. The method according to claim 1, characterized in that: The axial force increment matrix [ P T ] m×1 Calculated by the following formula: [ P T ] m×1 =[P d ] m×1 -[P t ] m×1 , In the formula, [P d ] m×1 is the axial force design value of the servo steel support, [P t ] m×1 is the measured value of the axial force of the servo steel support, [ P T ] m×1 is the total axial force increment matrix of the servo steel support when the axial force coherence is considered, m is the total number of servo steel supports, and T is the subscript symbol of the axial force variation considering the axial force coherence.

3. The method according to claim 1, characterized in that: The servo steel support axial force coherence coefficient matrix ξ m×m The determination includes the following steps: S1, obtaining a three-dimensional model of the foundation pit excavation project and determining the geometric model size of the foundation pit to be excavated; S2, the excavation depth is H m The construction simulation calculation is 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 tracks that need to be installed; S3, load the i-th servo steel support, collect data from the j-th servo steel support, and determine the servo steel support axial force coherence coefficient ξ j,i,m , S4, take j = j-1, collect the axial force of the j-1th servo steel support, repeat step S3, and determine the coherence coefficient of the axial force of the steel support ξ j,i,m ; Until j=1; S5, take i = i-1, axially load the i-1th servo steel support, repeat steps S3-S4, and determine the steel support axial force coherence coefficient ξ j,i,m ; Until i=1; S6, continue to excavate the foundation pit to a depth of H m , repeat steps S2-S5 until m=N, N is the last servo steel support, and all servo steel supports are erected.

4. 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 increments of any two servo steel supports. ξ m×m , including: axial force increment through the i-th servo steel support P i,i,m The axial force increment of the j-th servo steel support P j,i,m The data set is obtained, and the expression formula is: ,in, ξ j,i,m The calculation formula is: ξ j,i,m = P j,i,m / P i, i,m ， Among them, ξ j,i,m is the servo steel support axial force coherence coefficient matrix ξ m×m , i is the inspection track number of the servo system steel support with the same axial force value as the loading position, j is the inspection track number of the servo system steel support with passive axial force change, P i,i,m is the axial force increment of the i-th servo steel support when loading the i-th servo steel support, P j,i,m When loading the i-th servo steel support, the axial force increment of the j-th servo steel support is investigated.

5. The method according to claim 2, 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 equivalent relationship between the three is: [ P T ] m×1 =[ξ] m×m [ P] m×1 , In the formula, [ P] m×1 is the axial force increment matrix of the m-channel servo steel support when the servo steel support is loaded individually, and the axial force coherence effect is not considered at this time; [ P T ] m×1 is the total axial force increment matrix of the m-channel servo steel support, and the axial force coherence effect is considered at this time; [ξ] m×m is the structural coherence coefficient matrix of the servo steel support; m is the total number of servo steel supports.

6. The method according to claim 5, characterized in that: The axial force increment matrix [ P] m×1 Calculated by the following formula: [ P] m×1 = [ξ] -1 m×m [ P T ] m×1 , In the formula, [ P] m×1 is the axial force increment matrix of the m-channel servo steel support when the servo steel support is loaded individually without considering the coherent effect of the axial force; [P d ] m×1 is the axial force design value matrix of the servo steel support, [P t ] m×1 is the measured value matrix of the axial force of the servo steel support, and ξ is the coherence coefficient of the axial force of the steel support.

7. The method according to claim 6, characterized in that: The axial force increment matrix [ P] m×1 Calculated by the following formula: [ P] m×1 = [ξ] -1 m×m ([P d ] m×1 -[P t ] m×1 ).

8. The method according to claim 5, characterized in that: The axial force increment matrix [ P T ] m×1 The specific expansion form 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 is the axial force increment of the jth servo steel support in the foundation pit structure system. At this time, the coherent effect of the axial force is considered, where j = 1, 2, …, m, and m is the total number of servo steel supports; ξ j,i,m is the servo steel support axial force coherence coefficient, P i,i,m In order to i The axial load applied to the servo steel support is i The axial force increment of the servo steel support is calculated, and the axial force coherence effect is not considered at this time.

9. The method according to any one of claims 3 or 4, characterized in that: The servo steel support axial force coherence coefficient ξ j,i,m It reflects that the relationship between the change in the axial force of the examined steel support and the change in the axial force of the loaded steel support is consistent with the elastic theory and is fitted using a linear equation.

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