Intelligent control system and method for axial force of deep foundation pit steel support

Abstract

The invention discloses a deep foundation pit steel support axial force intelligent control system and method, and the method comprises the steps: receiving deep foundation pit data, including engineering design data and foundation pit real-time monitoring data; a deep foundation pit steel support rigidity model is established, and steel support deformation and axial force mapping is established; performing steel support temperature stress compensation calculation, and iteratively calculating the temperature influence axial force; the deformation axial force adjustment amount of the steel support is calculated, through deformation displacement data and axial force data collected in real time, the axial force change amount caused by deformation is calculated according to a foundation pit steel support rigidity model, and the final axial force adjustment amount is calculated; and after an adjustment amount instruction is issued for real-time regulation and control, a new round of adjustment amount calculation is conducted according to new real-time data, and timely deep foundation pit deformation response control is achieved. According to the method, the influence of the compensation environment temperature is eliminated, deformation-axial force mapping is established, closed-loop regulation and control of the axial force of the steel support are achieved, the manual pressurization regulation and control cost and energy ineffective loss are greatly reduced, and economical, reliable and environment-friendly intelligent control over the deep foundation pit is achieved.

Description

Technical Field

[0001] This invention relates to the field of axial force control technology for foundation pits, and particularly to an intelligent control system and method for axial force control of steel supports in deep foundation pits. Background Technology

[0002] As urban underground space development moves towards greater depth and scale, deep foundation pit projects are becoming increasingly large, placing higher demands on the stability control of the retaining structure. Current construction methods primarily rely on adjusting the axial force of steel supports to maintain foundation pit deformation within limits. The ability to respond and control in a timely manner based on real-time foundation pit deformation directly impacts foundation pit safety. However, existing steel support axial force servo systems suffer from a fundamental flaw: the control algorithm sets static axial force thresholds solely based on theoretical calculations from the design phase. In actual construction, existing servo systems typically undergo fixed adjustments every few days, a crude control approach severely detached from practical engineering realities.

[0003] On the one hand, the theoretical design values ​​cannot reflect the dynamic influence of the construction environment. During the excavation of the foundation pit, the earth pressure on the retaining structure is affected by multiple factors such as changes in the excavated soil, groundwater seepage, and disturbances from surrounding loads. The theoretical preset values ​​deviate significantly from the actual stress state. On the other hand, the inherent thermal expansion and contraction characteristics of steel make the axial force of the support extremely sensitive to temperature changes. The diurnal temperature difference can cause periodic fluctuations in the axial force, and the existing system has not established a temperature stress compensation mechanism at all.

[0004] Existing servo systems are insufficient to achieve timely and accurate control of foundation pit deformation. There is an urgent need to develop intelligent control algorithms and systems that take into account the influence of ambient temperature on the axial force of steel supports and can adapt to the dynamic changes in foundation pit construction. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent control algorithm and system for the axial force of steel supports in deep foundation pits, addressing the aforementioned shortcomings. This solves the problem that existing steel support axial force servo systems are unable to achieve dynamic control response of the steel support axial force due to temperature stress during foundation pit construction.

[0006] This invention is achieved through the following scheme: A deep foundation pit steel support axial force intelligent control system includes a data acquisition module, an axial force intelligent calculation platform, and a wireless oil-free pipe support servo system. The data acquisition module is used to collect temperature, displacement, and steel support axial force data in real time. The axial force intelligent calculation platform is used to calculate the axial force adjustment amount, and the wireless oil-free pipe support servo system is used to execute the axial force adjustment amount of the foundation pit. The data acquisition module is connected to the axial force intelligent calculation platform, and the axial force intelligent calculation platform is connected to the wireless oil-free pipe support servo system.

[0007] The data acquisition module specifically includes a temperature sensor and a foundation pit displacement monitoring sensor; the temperature sensor is installed on the steel support inside the foundation pit, and the foundation pit displacement monitoring sensor is installed at the upper end of the foundation pit retaining structure.

[0008] This solution also discloses an intelligent control method for axial force of steel supports in deep foundation pits, including the following steps: Step S1, Deployment of the foundation pit inherent parameter acquisition and data acquisition module; Step S2: The data acquisition module performs dynamic data acquisition in real time; Step S3: The data acquisition module uploads the collected data to the axial force intelligent calculation platform for calculation; the axial force intelligent calculation platform executes intelligent algorithms to calculate the axial force fluctuation value caused by temperature changes, performs temperature stress elimination compensation, and calculates the steel support axial force adjustment amount based on the deformation displacement of the enclosure structure and the current steel support axial force value according to the deformation axial force mapping. Step S4: Perform the adjustment steps.

[0009] In step S1, specifically, based on the original data of the foundation pit construction, the axial force intelligent calculation platform presets the inherent parameters of the foundation pit; and deploys temperature sensors on the steel supports; sets displacement detection sensors at the deformation monitoring points at the upper end of the foundation pit retaining structure; and arranges steel supports according to the construction progress, installing the servo system at the support end to ensure normal acquisition of axial force data by the servo system.

[0010] In step S2, the real-time acquisition of dynamic data specifically includes: the surface temperature value of the steel support measured by the temperature sensor; the current axial force value of the steel support fed back by the servo support head; and the displacement of the enclosure structure monitored in real time.

[0011] The intelligent algorithm in step S3 specifically includes the following steps: In step S31, the axial force intelligent calculation platform calculates the temperature-induced axial force adjustment caused by the iterative calculation based on the inherent parameters of the foundation pit and the stiffness-induced axial force adjustment based on the data acquisition module. After obtaining the final axial force adjustment, the axial force intelligent calculation platform issues an adjustment command for real-time control and performs a new round of adjustment calculation based on the new real-time data to achieve timely deep foundation pit deformation response control.

[0012] In step S31, the specific calculation of the temperature axial force adjustment caused by the temperature cycle fluctuation is as follows: establish a horizontal stiffness model of the deep foundation pit support structure, and perform iterative calculation of steel support temperature stress compensation to obtain the temperature axial force adjustment caused by the temperature cycle fluctuation.

[0013] The horizontal stiffness model of the foundation pit support structure is calculated based on the actual dimensions of the deep foundation pit using the following formula:

[0014] In the formula: A The cross-sectional area of ​​the support is expressed in meters (m²). 2 ; E The elastic modulus of the supporting material is expressed in kPa. l b The spacing between the support piles is in meters (m). θ The angle between the support and the capping beam is expressed in degrees. l s The length of the supporting component is expressed in meters (m). S 1. S 2 represents the horizontal calculation distance between the two sides of the support, in meters; β To adjust the coefficient, when the foundation pits on both sides are excavated symmetrically, take... β =0.5; for the side of the foundation pit with greater earth pressure or the side that was excavated first, take 0.5. β =1.0.

[0015] The iterative calculation for temperature stress compensation of steel supports is specifically based on the following formula:

[0016]

[0017] In the formula: assuming temperature axial force N Displacement is generated under the action of 0, and iterative calculation is performed. N i+1 until N i+1 and N i Similarly, at this point, the effect of temperature on axial force is obtained. ;in, α The coefficient of linear expansion of the supporting rod material; This refers to the temperature fluctuation value of the steel support. A The cross-sectional area of ​​the supporting member is expressed in meters (m). 2 ; E The elastic modulus of the supporting rod material is expressed in kPa. H This refers to the depth of the foundation pit excavation. H 1 represents the length of the retaining piles above the bottom of the foundation pit. H 2 represents the depth of the horizontal support from the bottom of the pit, in meters. m This is the proportionality coefficient of the soil's horizontal resistance coefficient, with units of kN / m. 4 ; L The support length is in meters (m). D The length of the foundation pit perimeter supported by a single support, in meters (m).

[0018] In step S4, specifically, the axial force intelligent calculation platform sends the axial force adjustment command to the wireless oil-free support servo system, and the hydraulic mechanism of the drive support head of the wireless oil-free support servo system performs the pressure adjustment operation; the axial force and deformation data after pressure adjustment are collected in real time and fed back to the calculation platform to start the next control cycle.

[0019] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. This solution provides an intelligent control algorithm and system for the axial force of steel supports in deep foundation pits. This algorithm is mature and practical, enabling axial force compensation control of steel supports in different foundation pit projects and with different steel support types. The key point of this invention is replacing traditional manual control with an intelligent control system. It fully considers environmental factors such as temperature changes, responds promptly to dynamic changes in the foundation pit, and intelligently adjusts the axial force of the steel supports by real-time monitoring of foundation pit data, quickly completing the control process, thus ensuring construction safety and reducing energy waste.

[0020] 2. This invention eliminates the influence of ambient temperature and establishes a deformation-axial force mapping to achieve closed-loop control of the axial force of the steel support, significantly reducing the cost of manual pressurization and energy waste, and realizing economical, reliable and environmentally friendly intelligent control of deep foundation pits. Attached Figure Description

[0021] Figure 1 This is a flowchart of the intelligent control method for axial force of steel support in deep foundation pits according to the present invention; Figure 2 This is a schematic diagram of an intelligent control system for axial force in deep foundation pits according to the present invention. Detailed Implementation

[0022] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0023] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0024] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a predetermined orientation, or be constructed and operated in a predetermined orientation. Therefore, they should not be construed as limitations on this invention.

[0025] Furthermore, 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 technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0026] Example 1 like Figure 1 As shown, the present invention provides a technical solution: A method for intelligent control of axial force in steel supports for deep foundation pits includes the following steps: Step S1, Deployment of the foundation pit inherent parameter acquisition and data acquisition module; Specifically, based on the original data of the foundation pit construction, the axial force intelligent calculation platform presets the inherent parameters of the foundation pit; and deploys temperature sensors on the steel supports; sets displacement detection sensors at the deformation monitoring points at the upper end of the foundation pit retaining structure; and arranges steel supports according to the construction progress, installing the servo system at the support end to ensure normal acquisition of axial force data by the servo system.

[0027] The inherent parameters of the foundation pit may include the elastic modulus of the support, cross-sectional area, length, and excavation depth, etc. Step S2: The data acquisition module performs dynamic data acquisition in real time; The dynamic data acquisition in real time specifically includes: the surface temperature value of the steel support measured by the temperature sensor; the current axial force value of the steel support fed back by the servo support head; and the displacement of the enclosure structure monitored in real time. Step S3: The data acquisition module uploads the acquired data to the axial force intelligent calculation platform for calculation. The axial force intelligent calculation platform executes intelligent algorithms to calculate the axial force fluctuation value caused by temperature changes, performs temperature stress elimination compensation, and calculates the steel support axial force adjustment amount based on the deformation displacement of the enclosure structure and the current steel support axial force value according to the deformation axial force mapping.

[0028] Step S4, perform the adjustment steps: The axial force intelligent calculation platform sends the axial force adjustment command to the wireless oil-free support servo system. The drive support head hydraulic mechanism of the wireless oil-free support servo system performs the pressure adjustment operation; the axial force and deformation data after pressure adjustment are collected in real time and fed back to the calculation platform to start the next control cycle.

[0029] In step S3, the intelligent algorithm may specifically include the following steps: Step S31: The axial force intelligent calculation platform calculates the temperature axial force adjustment caused by the iterative calculation due to temperature cycle fluctuations and the stiffness axial force adjustment caused by deformation, based on the inherent parameters of the foundation pit and the data acquisition module. After obtaining the final axial force adjustment, the axial force intelligent calculation platform issues the adjustment command for real-time control and performs a new round of adjustment calculation based on the new real-time data to achieve timely deep foundation pit deformation response control. In step S31, the specific calculation of the temperature axial force adjustment caused by the temperature cycle fluctuation is as follows: establish a horizontal stiffness model of the deep foundation pit support structure, and perform iterative calculation of steel support temperature stress compensation to obtain the temperature axial force adjustment caused by the temperature cycle fluctuation. The horizontal stiffness model of the foundation pit support structure is calculated based on the actual dimensions of the deep foundation pit using the following formula:

[0030] In the formula: A The cross-sectional area of ​​the support is expressed in meters (m²). 2 ; E The elastic modulus of the supporting material is expressed in kPa. l b The spacing between the support piles is in meters (m). θ The angle between the support and the capping beam is expressed in degrees. l s The length of the supporting component is expressed in meters (m). S 1. S 2 represents the horizontal calculation distance between the two sides of the support, in meters; β To adjust the coefficient, when the foundation pits on both sides are excavated symmetrically, take... β =0.5; for the side of the foundation pit with greater earth pressure or the side that was excavated first, take 0.5. β =1.0; The iterative calculation for temperature stress compensation of steel supports is specifically based on the following formula:

[0031]

[0032] In the formula: assuming temperature axial force N Displacement is generated under the action of 0, and iterative calculation is performed. N i+1 until N i+1 and N i Similarly, at this point, the effect of temperature on axial force is obtained. .in, α The coefficient of linear expansion of the supporting rod material; This refers to the temperature fluctuation value of the steel support. AThe cross-sectional area of ​​the supporting member is expressed in meters (m). 2 ; E The elastic modulus of the supporting rod material is expressed in kPa. H This refers to the depth of the foundation pit excavation. H 1 represents the length of the retaining piles above the bottom of the foundation pit. H 2 represents the depth of the horizontal support from the bottom of the pit, in meters. m This is the proportionality coefficient of the soil's horizontal resistance coefficient, with units of kN / m. 4 ; L The support length is in meters (m). D The length of the foundation pit perimeter supported by a single support, in meters (m).

[0033] The above formula mainly considers the interaction between the support, retaining piles, and soil, and is a formula for calculating axial force under the influence of structural temperature.

[0034] The final axial force adjustment includes the iteratively calculated temperature axial force caused by temperature cycle fluctuations and the stiffness calculated axial force caused by deformation, and the two are superimposed to obtain the final axial force adjustment. In step S31, the deformation displacement data and axial force data collected in real time are used to calculate the change in axial force caused by deformation based on the stiffness model of the foundation pit steel support. Specifically, this is based on the existing soil mechanics theory model and the calculation principle of steel structure.

[0035] Example 2 like Figure 2 As shown, the present invention provides a technical solution: A deep foundation pit steel support axial force intelligent control system includes a data acquisition module, an axial force intelligent calculation platform, and a wireless oil-free pipe support servo system. The data acquisition module is used to collect temperature, displacement, and steel support axial force data in real time. The axial force intelligent calculation platform is used to calculate the axial force adjustment amount, and the wireless oil-free pipe support servo system is used to execute the axial force adjustment amount of the foundation pit. The data acquisition module is connected to the axial force intelligent calculation platform, and the axial force intelligent calculation platform is connected to the wireless oil-free pipe support servo system.

[0036] Based on the above structure, this solution uses a data acquisition module to collect temperature, displacement, and steel support axial force data in real time. The data acquisition module uploads the data to the axial force intelligent calculation platform to calculate the axial force adjustment. After calculation, the axial force intelligent calculation platform sends adjustment instructions to the wireless oil-free support servo system. The wireless oil-free support servo system drives the hydraulic system to perform control operations. After the wireless oil-free support servo system performs control, it continues to collect real-time data through the data acquisition module for the next round of control.

[0037] As an example, the data acquisition module may specifically include a temperature sensor and a foundation pit displacement monitoring sensor; the temperature sensor is installed on the steel support inside the foundation pit, and the foundation pit displacement monitoring sensor is installed at the upper end of the foundation pit retaining structure.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An intelligent control system for axial force of steel supports in deep foundation pits, characterized in that: It includes a data acquisition module, an intelligent axial force calculation platform, and a wireless oil-free pipe support servo system; the data acquisition module is used to collect temperature, displacement, and steel support axial force data in real time; the intelligent axial force calculation platform is used to calculate the axial force adjustment amount; and the wireless oil-free pipe support servo system is used to execute the axial force adjustment amount of the foundation pit. The data acquisition module is connected to the axial force intelligent calculation platform, which in turn is connected to the wireless oil-free pipe support servo system.

2. The intelligent control system for axial force of steel support in deep foundation pits as described in claim 1, characterized in that: The data acquisition module specifically includes a temperature sensor and a foundation pit displacement monitoring sensor; the temperature sensor is installed on the steel support inside the foundation pit, and the foundation pit displacement monitoring sensor is installed at the upper end of the foundation pit retaining structure.

3. A method for intelligent control of axial force in steel supports for deep foundation pits, based on the control system described in claim 1 or 2, characterized in that: Includes the following steps: Step S1, Deployment of the foundation pit inherent parameter acquisition and data acquisition module; Step S2: The data acquisition module performs dynamic data acquisition in real time; Step S3: The data acquisition module uploads the acquired data to the axial force intelligent calculation platform for calculation. The axial force intelligent calculation platform executes intelligent algorithms to calculate the axial force fluctuation value caused by temperature changes, performs temperature stress elimination compensation, and calculates the steel support axial force adjustment amount based on the deformation displacement of the enclosure structure and the current steel support axial force value according to the deformation axial force mapping. Step S4: Perform the adjustment steps.

4. The intelligent control method for axial force of steel support in deep foundation pits as described in claim 3, characterized in that: In step S1, specifically, based on the original data of the foundation pit construction, the axial force intelligent calculation platform presets the inherent parameters of the foundation pit; and deploys temperature sensors on the steel supports; sets displacement detection sensors at the deformation monitoring points at the upper end of the foundation pit retaining structure; and arranges steel supports according to the construction progress, installing the servo system at the support end to ensure normal acquisition of axial force data by the servo system.

5. The intelligent control method for axial force of steel support in deep foundation pits as described in claim 3, characterized in that: In step S2, the real-time acquisition of dynamic data specifically includes: the surface temperature value of the steel support measured by the temperature sensor; the current axial force value of the steel support fed back by the servo support head; and the displacement of the enclosure structure monitored in real time.

6. The intelligent control method for axial force of steel support in deep foundation pits as described in claim 3, characterized in that: The intelligent algorithm in step S3 specifically includes the following steps: In step S31, the axial force intelligent calculation platform calculates the temperature-induced axial force adjustment caused by the iterative calculation based on the inherent parameters of the foundation pit and the stiffness-induced axial force adjustment based on the data acquisition module. After obtaining the final axial force adjustment, the axial force intelligent calculation platform issues an adjustment command for real-time control and performs a new round of adjustment calculation based on the new real-time data to achieve timely deep foundation pit deformation response control.

7. The intelligent control method for axial force of steel support in deep foundation pits as described in claim 6, characterized in that: In step S31, the specific calculation of the temperature axial force adjustment caused by the temperature cycle fluctuation is as follows: establish a horizontal stiffness model of the deep foundation pit support structure, and perform iterative calculation of steel support temperature stress compensation to obtain the temperature axial force adjustment caused by the temperature cycle fluctuation.

8. The intelligent control method for axial force of steel support in deep foundation pits as described in claim 7, characterized in that: The horizontal stiffness model of the foundation pit support structure is calculated based on the actual dimensions of the deep foundation pit using the following formula: In the formula: A The cross-sectional area of ​​the support is expressed in meters (m²). 2 ; E The elastic modulus of the supporting material is expressed in kPa. l b The spacing between the support piles is in meters (m). θ The angle between the support and the capping beam is expressed in degrees. l s The length of the supporting component is expressed in meters (m). S 1. S 2 represents the horizontal calculation distance between the two sides of the support, in meters; β To adjust the coefficient, when the foundation pits on both sides are excavated symmetrically, take... β =0.5; for the side of the foundation pit with greater earth pressure or the side that was excavated first, take 0.

5. β =1.

0.

9. The intelligent control method for axial force of steel support in deep foundation pits as described in claim 6, characterized in that: The iterative calculation for temperature stress compensation of steel supports is specifically based on the following formula: In the formula: assuming temperature axial force N Displacement is generated under the action of 0, and iterative calculation is performed. N i+1 until N i+1 and N i Similarly, at this point, the effect of temperature on axial force is obtained. ;in, α The coefficient of linear expansion of the supporting rod material; This refers to the temperature fluctuation value of the steel support. A The cross-sectional area of ​​the supporting member is expressed in meters (m). 2 ; E The elastic modulus of the supporting rod material is expressed in kPa. H This refers to the depth of the foundation pit excavation. H 1 represents the length of the retaining piles above the bottom of the foundation pit. H 2 represents the depth of the horizontal support from the bottom of the pit, in meters. m This is the proportionality coefficient of the soil's horizontal resistance coefficient, with units of kN / m. 4 ; L The support length is in meters (m). D The length of the foundation pit perimeter supported by a single support, in meters (m).

10. A method for intelligent control of axial force in steel supports for deep foundation pits as described in any one of claims 3 to 9, characterized in that: In step S4, specifically, the axial force intelligent calculation platform sends the axial force adjustment command to the wireless oil-free support servo system, and the hydraulic mechanism of the drive support head of the wireless oil-free support servo system performs the pressure adjustment operation; the axial force and deformation data after pressure adjustment are collected in real time and fed back to the calculation platform to start the next control cycle.

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