A foundation pit support monitoring and early warning method and foundation pit support monitoring and early warning system

Abstract

The present invention relates to the technical field of foundation pit support, and discloses a foundation pit support monitoring and early warning system, including a software model system, an on-site support system, a deformation monitoring system, a safety early warning system and a graphic digital display system, and also discloses a foundation pit support monitoring and early warning method, including the following steps: S1, geological data input; S2, soil model establishment; S3, support structure model establishment; S4, support structure on-site arrangement; S5, deformation monitoring establishment; S6, safety early warning establishment. The present invention uses a reinforcement method of geological data input, soil model establishment, support structure model establishment, support structure on-site arrangement, deformation monitoring establishment and safety early warning establishment, thereby dynamically monitoring the foundation pit through the combination of the model and the work site, thereby comprehensively reflecting the influence of various factors on the support structure and the stress and displacement of the axonal soil in space and time, and realizing the safety during the excavation of the foundation pit.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit support, and in particular to a foundation pit support monitoring and early warning method and a foundation pit support monitoring and early warning system. Background Art

[0002] With the rapid development of cities, land resources are becoming increasingly scarce. People are developing underground spaces, including basements, subways, underground garages, air-raid shelters, etc., which all require excavation of foundation pits. In urban areas, there are usually no conditions for slope excavation, and foundation pit excavation with a support system is required, especially for soft soil foundations and high groundwater levels, which are prone to instability and may cause major safety and quality accidents. Therefore, the foundation pit support monitoring and early warning system is particularly important.

[0003] A Chinese patent discloses a stability detection and early warning method for deep foundation pit support structures (authorization announcement number CN104452836A). This patented technology changes the idea of ​​the traditional displacement time series prediction method of only selecting landslide displacement or displacement rate as monitoring and evaluation parameters. It synchronously monitors and calculates the change value of the dynamic load generated by the excavation and unloading of the foundation pit and the foundation pit displacement or displacement rate, and gives specific coupled monitoring and early warning values. However, it does not realize the combination of the model and the work site, and thus cannot fully reflect the impact of factors on the deformation of the foundation pit. Summary of the invention

[0004] The purpose of the present invention is to provide a foundation pit support monitoring and early warning method and a foundation pit support monitoring and early warning system to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A foundation pit support monitoring and early warning system comprises a software model system, an on-site support system, a deformation monitoring system, a safety early warning system and a graphic digital display system. The software model system is composed of a geological data module, a support structure model module and a soil model module. The software model system is used to input address data, establish a soil model and a support structure model of a foundation pit, and calculate the deformation stress and load of the foundation pit according to the soil model and the support structure model.

[0007] The field support system is used to arrange the field excavation support according to the construction drawings and install monitoring points;

[0008] The deformation monitoring system is used to calculate the displacement of the support structure and map the output parameters and input parameters of the displacement of the foundation pit support structure;

[0009] The safety warning system is used to provide safety warnings for abnormal situations during the foundation pit monitoring process;

[0010] The graphic digital display system is used to display monitored data, images and lists.

[0011] A foundation pit support monitoring and early warning method comprises the following steps:

[0012] S1. Input of geological data: Input the geological data around the foundation pit according to the survey documents; the geological data include the plane coordinates of each survey hole, the elevation of the vertical soil layer, and the physical and mechanical indicators of each soil layer;

[0013] S2. Establishment of soil model: Divide the foundation pit into equivalent finite element combinations according to the soil layer, excavation depth and excavation section of the foundation pit soil, define the coordinate position and stiffness matrix of each finite element combination, establish the equilibrium equation, and calculate the coordinate displacement and load of the finite element combination;

[0014] S3. Establishment of support structure model: define and arrange support, bracing, anchoring structure types and load sizes; divide and number support, bracing, anchoring structures according to input geological data and soil model, classify and merge units, calculate the stiffness matrix of each unit, calculate the active earth pressure and external load pressure borne by each unit, establish equilibrium equations according to the stiffness matrix and coordinate position of each unit, and calculate the displacement and load of each coordinate of support, bracing, anchoring structure;

[0015] S4. On-site arrangement of support structure: Complete the construction drawing of the foundation pit support system according to the support structure model data, carry out support operations on the foundation pit at the construction site according to the construction drawing, arrange monitoring points, monitor and collect foundation pit data;

[0016] S5. Establishment of deformation monitoring: Establish a neural network prediction model based on the neural network prediction method with measured data as the learning sample, calculate the displacement of the support structure, and use the high mapping ability and calculation ability of the neural network to achieve the mapping of the output parameters and input parameters of the displacement of the foundation pit support structure;

[0017] S6. Establishment of safety warning: Safety warning is carried out during the monitoring process through the support structure safety warning system. When the safety alarm value is exceeded or the monitoring value changes abnormally, a warning is issued to remind the monitoring personnel to correct the deviation in time, and the warning is displayed through the graphic digital display system.

[0018] As a further solution of the present invention: the input parameters in step S5 include: foundation pit area, foundation pit width-to-length ratio, foundation pit depth, soil weight, internal friction angle, cohesion, support type, number of support paths, groundwater level and ground load;

[0019] The output parameters in step S5 include: maximum horizontal displacement of the wall top, maximum horizontal position of the wall, vertical displacement, surrounding surface settlement, and soil uplift at the bottom of the pit.

[0020] As a further solution of the present invention: the graphic digital display system in step S6 is composed of a pre-processing module, a solution module and a post-processing module: the pre-processing module is used to read and establish a model, select a unit type, define a material type, assign material properties, divide the grid, and specify a load step;

[0021] The solution module is used to define the analysis type; specify the load step, start the solution, repeat the load option, and solve the subsequent load steps;

[0022] The post-processing is used to display the deformed shape, display the contour line, and display the list.

[0023] As a further solution of the present invention: the calculation formula of the equilibrium equation in step S2 is as follows:

[0024] [k]{δ}=[R] (1)

[0025] In the above formula (1), [k] is the overall stiffness matrix; {δ} is the displacement of each coordinate; and [R] is the coordinate load.

[0026] As a further solution of the present invention: the calculation formula of the load strength of the soil in step S2 is as follows:

[0027]

[0028] In the above formula (2), a is the cohesion and internal friction angle Related parameters, I 1 is the first invariant of the stress tensor, I 1 =σ 1 +σ 2 +σ 3 ; J 2 is the second invariant of stress deviator, J 2 =1 / 6[(σ 1 -σ 2 ) 2 +(σ 1 -σ 3 ) 2 +(σ 2 -σ 3 ) 2 ]; σ 1 , σ 2 , σ 3 is the effective stress.

[0029] As a further solution of the present invention: the support structure safety early warning system is composed of a learning sample library, an actual displacement model, an early warning indicator system, a safety early warning analysis module, an alarm decision module and a data monitoring and collection module.

[0030] As a further solution of the present invention: the workflow of the support structure safety early warning system includes the following steps:

[0031] S11. Collect data examples of monitoring and collection of foundation pits in similar areas to build a learning sample library;

[0032] S12, inputting relevant parameters of the foundation pit through the data monitoring and acquisition module, and performing inversion analysis on the neural network prediction model and the data monitoring and acquisition module to establish an actual displacement model; and predicting the actual displacement value;

[0033] S13. Establish an indicator system based on current laws, regulations, and standard control values, and set safety alarm values;

[0034] S14. The actual displacement prediction value is analyzed and compared with the safety alarm value through the safety early warning analysis module, and sent to the alarm decision module to determine whether an alarm is needed.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention supports and monitors the foundation pit through a software model system, an on-site support system, a deformation monitoring system, a safety warning system and a graphic digital display system, and through a reinforcement method of geological data input, soil model establishment, support structure model establishment, on-site arrangement of support structure, deformation monitoring establishment and safety warning establishment, the foundation pit is dynamically monitored through the combination of the model and the work site, thereby comprehensively reflecting the influence of various factors on the support structure and the stress and displacement of the axonal soil in space and time, and achieving safety during the excavation of the foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a structural schematic diagram of a foundation pit support monitoring and early warning system;

[0038] Figure 2 It is a flow chart of a foundation pit support monitoring and early warning method;

[0039] Figure 3 The figure is a schematic diagram of the working process of a safety early warning system in a foundation pit support monitoring and early warning system. DETAILED DESCRIPTION

[0040] See also Figures 1 to 3In an embodiment of the present invention, a foundation pit support monitoring and early warning system includes a software model system, an on-site support system, a deformation monitoring system, a safety early warning system and a graphic digital display system. The software model system is composed of a geological data module, a support structure model module and a soil model module. The software model system is used to input address data, establish a soil model and a support structure model of the foundation pit, and calculate the deformation stress and load of the foundation pit according to the soil model and the support structure model;

[0041] The field support system is used to arrange the field excavation support according to the construction drawings and install monitoring points;

[0042] The deformation monitoring system is used to calculate the displacement of the support structure and map the output parameters and input parameters of the displacement of the foundation pit support structure;

[0043] The safety early warning system is used to provide safety early warnings for abnormal situations during foundation pit monitoring;

[0044] The graphic digital display system is used to display monitored data, images and lists.

[0045] A foundation pit support monitoring and early warning method comprises the following steps:

[0046] S1. Geological data input: input the geological data around the foundation pit according to the survey documents; the geological data include the plane coordinates of each survey hole, the vertical soil layer elevation, and the physical and mechanical indicators of each soil layer;

[0047] S2. Establishment of soil model: Divide the foundation pit into equivalent finite element combinations according to the soil layer, excavation depth and excavation section of the foundation pit soil, define the coordinate position and stiffness matrix of each finite element combination, establish the equilibrium equation, and calculate the coordinate displacement and load of the finite element combination;

[0048] S3. Establishment of support structure model: define and arrange the types of support, bracing and anchoring structures and load sizes, which can provide data for calculation and provide accurate dimensions of structural components for construction drawings; divide and number the support, bracing and anchoring structures according to the input geological data and soil model, classify and merge the units, calculate the stiffness matrix of each unit, calculate the active earth pressure and external load pressure borne by each unit, establish equilibrium equations according to the stiffness matrix and coordinate position of each unit, and calculate the displacement and load of each coordinate of the support, bracing and anchoring structures;

[0049] S4. On-site arrangement of support structure: Complete the construction drawing of the foundation pit support system according to the support structure model data, carry out support operations on the foundation pit at the construction site according to the construction drawing, and arrange monitoring points, including inclinometers, settlement monitoring points, and steel bar meters, to monitor and collect foundation pit data;

[0050] S5. Establishment of deformation monitoring: Establish a neural network prediction model based on the neural network prediction method with measured data as the learning sample, calculate the displacement of the support structure, and use the high mapping ability and calculation ability of the neural network to achieve the mapping of the output parameters and input parameters of the displacement of the foundation pit support structure;

[0051] S6. Establishment of safety warning: Safety warning is carried out during the monitoring process through the support structure safety warning system. When the safety alarm value is exceeded or the monitoring value changes abnormally, a warning is issued to remind the monitoring personnel to correct the deviation in time, and the warning is displayed through the graphic digital display system.

[0052] Preferably, the input parameters in step S5 include: foundation pit area, foundation pit width-to-length ratio, foundation pit depth, soil weight, internal friction angle, cohesion, support type, number of support paths, groundwater level and ground load; according to the type of support structure, it may also include foundation pit excavation elevation, side wall importance coefficient, coordinates of each vertex of the foundation pit edge; cross-sectional type and material of piles, walls, beams, internal supports, types of anchors and connecting beams; number of piles, walls, anchors and connecting beams; control coordinates of each pile and wall; top surface elevation and length, number and elevation of horizontal support layers, control coordinates of anchors and connecting beams;

[0053] The output parameters in step S5 include: maximum horizontal displacement of the wall top, maximum horizontal position of the wall, vertical displacement, surrounding surface settlement, and soil uplift at the bottom of the pit.

[0054] Preferably, the graphic digital display system in step S6 is composed of a pre-processing module, a solution module and a post-processing module: the pre-processing module is used to read and establish the model, select the unit type, define the material type, assign material properties, divide the grid, and specify the load step;

[0055] The solver module is used to define the analysis type; specify the load step, start the solution, repeat the load option, and solve the subsequent load steps;

[0056] Post-processing is used to display deformed shapes, display contours, and display lists.

[0057] Preferably, the calculation formula of the equilibrium equation in step S2 is as follows:

[0058] [k]{δ}=[R] (1)

[0059] In the above formula (1), [k] is the overall stiffness matrix; {δ} is the displacement of each coordinate; and [R] is the coordinate load.

[0060] Preferably, the calculation formula for the load strength of the soil in step S2 is as follows:

[0061]

[0062] In the above formula (2), a is the cohesion and internal friction angle Related parameters, I 1 is the first invariant of the stress tensor, I 1 =σ 1 +σ 2 +σ 3 ; J 2 is the second invariant of stress deviator, J 2 =1 / 6[(σ 1 -σ 2 ) 2 +(σ 1 -σ 3 ) 2 +(σ 2 -σ 3 ) 2 ]; σ 1 , σ 2 , σ 3 is the effective stress.

[0063] Preferably, the support structure safety early warning system consists of a learning sample library, an actual displacement model, an early warning indicator system, a safety early warning analysis module, an alarm decision module and a data monitoring and collection module.

[0064] Preferably, the workflow of the support structure safety early warning system includes the following steps:

[0065] S11. Collect data examples of monitoring and collection of foundation pits in similar areas to build a learning sample library;

[0066] S12, inputting relevant parameters of the foundation pit through the data monitoring and acquisition module, and performing inversion analysis on the neural network prediction model and the data monitoring and acquisition module to establish an actual displacement model; and predicting the actual displacement value;

[0067] S13. Establish an indicator system based on current laws, regulations, and standard control values, and set safety alarm values;

[0068] S14. The actual displacement prediction value is analyzed and compared with the safety alarm value through the safety warning analysis module, and sent to the alarm decision module to determine whether an alarm is needed; the alarm modes include over-limit alarm of single factor affecting structural safety, structural system safety attention alarm and structural system safety emergency alarm.

[0069] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A foundation pit support monitoring and early warning system, comprising a software model system, an on-site support system, a deformation monitoring system, a safety early warning system and a graphic digital display system, characterized in that: The software model system is composed of a geological data module, a support structure model module and a soil model module. The software model system is used to input address data, establish a soil model and a support structure model of a foundation pit, and calculate the deformation stress and load of the foundation pit according to the soil model and the support structure model; the support structure model first defines and arranges the support, support, and anchor structure types and load sizes; the support, support, and anchor structure are divided and numbered according to the input geological data and soil model, and the units are classified and merged, and the stiffness matrix of each unit is calculated, and the active earth pressure and external load pressure borne by each unit are calculated. According to the stiffness matrix and coordinate position of each unit, an equilibrium equation is established to calculate the displacement and load of each coordinate of the support, support, and anchor structure; The field support system is used to arrange the field excavation support according to the construction drawings and install monitoring points; The deformation monitoring system is used to calculate the displacement of the support structure and map the output parameters and input parameters of the displacement of the foundation pit support structure; The safety warning system is used to provide safety warnings for abnormal situations during the foundation pit monitoring process; The support structure safety early warning system is composed of a learning sample library, an actual displacement model, an early warning indicator system, a safety early warning analysis module, an alarm decision module and a data monitoring and collection module; The graphic digital display system is used to display monitored data, images and lists.

2. The foundation pit support monitoring and early warning method implemented by the foundation pit support monitoring and early warning system according to claim 1 is characterized in that: The following steps are involved: S1. Input of geological data: Input the geological data around the foundation pit according to the survey documents; the geological data include the plane coordinates of each survey hole, the elevation of the vertical soil layer, and the physical and mechanical indicators of each soil layer; S2. Establishment of soil model: Divide the foundation pit into equivalent finite element combinations according to the soil layer, excavation depth and excavation section of the foundation pit soil, define the coordinate position and stiffness matrix of each finite element combination, establish the equilibrium equation, and calculate the coordinate displacement and load of the finite element combination; S3. Establishment of support structure model: define and arrange support, bracing, anchoring structure types and load sizes; divide and number support, bracing, anchoring structures according to input geological data and soil model, classify and merge units, calculate the stiffness matrix of each unit, calculate the active earth pressure and external load pressure borne by each unit, establish equilibrium equations according to the stiffness matrix and coordinate position of each unit, and calculate the displacement and load of each coordinate of support, bracing, anchoring structure; S4. On-site arrangement of support structure: Complete the construction drawing of the foundation pit support system according to the support structure model data, carry out support operations on the foundation pit at the construction site according to the construction drawing, arrange monitoring points, monitor and collect foundation pit data; S5. Establishment of deformation monitoring: Establish a neural network prediction model based on the neural network prediction method with measured data as the learning sample, calculate the displacement of the support structure, and use the high mapping ability and calculation ability of the neural network to achieve the mapping of the output parameters and input parameters of the displacement of the foundation pit support structure; S6. Establishment of safety warning: Safety warning is carried out during the monitoring process through the support structure safety warning system. When the safety alarm value is exceeded or the monitoring value changes abnormally, a warning is issued to remind the monitoring personnel to correct the deviation in time, and the warning is displayed through the graphic digital display system.

3. A foundation pit support monitoring and early warning method according to claim 2, characterized in that: The input parameters in step S5 include: foundation pit area, foundation pit width-to-length ratio, foundation pit depth, soil weight, internal friction angle, cohesion, support type, number of support paths, groundwater level and ground load; The output parameters in step S5 include: maximum horizontal displacement of the wall top, maximum horizontal position of the wall, vertical displacement, surrounding surface settlement, and soil uplift at the bottom of the pit.

4. A foundation pit support monitoring and early warning method according to claim 2, characterized in that: The graphic digital display system in step S6 is composed of a pre-processing module, a solution module and a post-processing module: the pre-processing module is used to read and establish a model, select a unit type, define a material type, assign material properties, divide the grid, and specify a load step; The solution module is used to define the analysis type; specify the load step, start the solution, repeat the load option, and solve the subsequent load steps; The post-processing is used to display the deformed shape, display the contour line, and display the list.

5. A foundation pit support monitoring and early warning method according to claim 2, characterized in that: The calculation formula of the equilibrium equation in step S2 is as follows: [k]{δ}=[R] (1) In the above formula (1), [k] is the overall stiffness matrix; {δ) is the displacement of each coordinate; [R] is the coordinate load.

6. A foundation pit support monitoring and early warning method according to claim 2, characterized in that: The calculation formula of the load strength of the soil in step S2 is as follows: In the above formula (2), a is the cohesion and internal friction angle Related parameters, I1 is the first invariant of the stress tensor, I1 = σ1 + σ2 + σ3; J2 is the second invariant of the stress deviator, J2 = 1 / 6[(σ1-σ2) 2 +(σ1-σ3) 2 +(σ2-σ3) 2 ]; σ1, σ2, σ3 are effective stresses.

7. A foundation pit support monitoring and early warning method according to claim 2, characterized in that: The workflow of the support structure safety early warning system includes the following steps: S11. Collect data examples of monitoring and collection of foundation pits in similar areas to build a learning sample library; S12, inputting relevant parameters of the foundation pit through the data monitoring and acquisition module, and performing inversion analysis on the neural network prediction model and the data monitoring and acquisition module to establish an actual displacement model; and predicting the actual displacement value; S13. Establish an indicator system based on current laws, regulations, and standard control values, and set safety alarm values; S14. The actual displacement prediction value is analyzed and compared with the safety alarm value through the safety early warning analysis module, and sent to the alarm decision module to determine whether an alarm is needed.

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