Deformation monitoring system for vertical supporting body of foundation pit in hydraulic reclamation area

Abstract

The invention discloses a deformation monitoring system for a vertical supporting body of a foundation pit in a hydraulic reclamation area, which relates to the technical field of deformation monitoring and comprises a multi-source signal acquisition module, a dynamic environment acquisition module, a fusion identification module, a dynamic analysis module and a dynamic early warning module. Millisecond-level deformation signal capture is achieved, five key parameters including axial strain, lateral displacement, soil pressure, pore water pressure and water level are synchronously collected, the blind area problem of single-index monitoring is solved, the safety coefficient K is corrected by calculating a comprehensive deformation value Q and then introducing a pore water pressure change rate U3 and a water level change rate W3, the data fusion efficiency is improved, and the data fusion precision is improved. The problem of data islands is solved, multi-stage response is triggered according to the K value, regulation and control equipment and personnel evacuation are linked, the early warning response efficiency is improved, and the engineering defense value of the deformation monitoring system under the complex working condition of the hydraulic reclamation area is improved.

Description

Technical Field

[0001] The invention relates to the technical field of deformation monitoring, and in particular to a deformation monitoring system for a vertical support body of a foundation pit in a filling area. Background Art

[0002] Due to the special geological conditions of the foundation pit engineering in the reclamation area (such as highly compressible reclamation soil, low foundation bearing capacity, and long soil consolidation period), its vertical support bodies (steel sheet piles, underground continuous walls, etc.) face serious deformation risks during construction and service. According to statistics, among the foundation pit accidents in the coastal reclamation area in my country, the collapse caused by the instability of the support body accounts for 37%, and the accident rate increases by 15% annually. Traditional deformation monitoring technology mainly relies on manual inspection, single-point displacement meter or static strain measurement.

[0003] The existing system monitors time-sensitive faults, and the sampling frequency of traditional systems is generally less than 1 time / hour, which cannot capture the nonlinear deformation characteristics caused by the dynamic consolidation of dredger fill. Studies have shown that under precipitation or excavation disturbances, the instantaneous displacement rate of the support body can reach 5-8mm / h, while the 4-6 hour response cycle of manual inspections will cause up to 92% of transient risks to be missed.

[0004] Moreover, in the deformation monitoring of foundation pit support bodies in filling areas, data islanding is manifested in that multi-source monitoring parameters (such as displacement, soil pressure, pore water pressure, etc.) are stored in a dispersed manner and cannot be deeply integrated due to the independent deployment of sensors and heterogeneous communication protocols, which seriously weakens the engineering defense value of the deformation monitoring system under complex working conditions in filling areas. Summary of the invention

[0005] In view of the above situation, the present invention can calculate the comprehensive deformation value Q, and then introduce the pore water pressure change rate U3 and the water level change rate W3 to correct the safety factor K, and trigger a multi-level response according to the K value, thereby improving the engineering defense value of the deformation monitoring system under complex working conditions in the filling area.

[0006] The technical solution is to include a multi-source signal acquisition module, a dynamic environment acquisition module, a fusion recognition module, a dynamic analysis module, and a dynamic warning module. The multi-source signal acquisition module uses a distributed fiber grating sensor and a MEMS tilt sensor to coordinate deployment to obtain the axial strain signal F and the lateral displacement signal D of the support body in real time. The dynamic environment acquisition module integrates an earth pressure box, a pore water pressure gauge and a groundwater level sensor to synchronously acquire earth pressure signals P, pore water pressure signals U and water level signals W; The fusion recognition module extracts the corresponding support body axial strain threshold F1, lateral displacement threshold D1, soil pressure threshold P1, pore water pressure threshold U1, and water level threshold W1 from the database, and calculates the comprehensive deformation value Q; The dynamic analysis module extracts the pore water pressure signal U2 and the water level signal W2 in adjacent time periods, calculates the pore water pressure change rate U3, and synchronously calculates the water level change rate W3; Calculate the support body safety value K, K = 1.5 ÷ [Q × (1 + 0.2 × U3 + 0.1 × W3)]; The dynamic warning module triggers a multi-level response according to the K value, linking the control equipment and personnel evacuation.

[0007] Furthermore, the multi-source signal acquisition module and the dynamic environment acquisition module add a unified timestamp to the corresponding sensor data through the Beidou dual-mode timing module, and the timing accuracy is ≤1ms. The corresponding sensors include distributed fiber grating sensors, MEMS inclination sensors, earth pressure boxes and pore water pressure gauges, among which the groundwater level sensor adopts independent clock synchronization with an error of ≤1s.

[0008] Furthermore, the fusion recognition module takes the support body axial strain signal F, lateral displacement signal D, soil pressure signal P, pore water pressure signal U and water level signal W with the same timestamp as a group of signals, and then extracts the corresponding support body axial strain threshold F1, lateral displacement threshold D1, soil pressure threshold P1 and pore water pressure threshold U1, water level threshold W1 in the database to calculate the comprehensive deformation value Q, Q=0.3×(F÷F1)+0.2×(D÷D1)+0.2×(P÷P1)+0.2×(U÷U1)+0.1×(W÷W1).

[0009] Furthermore, the dynamic analysis module extracts the pore water pressure signal U2 and the water level signal W2 in adjacent time, where the adjacent time is 5 minutes, calculates the pore water pressure change rate U3=|U1-U2|÷5, and simultaneously calculates the water level change rate W3=|W1-W2|÷5.

[0010] Furthermore, the dynamic warning module triggers a multi-level response according to the K value, linking the control equipment and personnel evacuation. When 1.2 ≤ K<1.5, a yellow alarm is triggered, and the precipitation rate is automatically reduced to 80% of the design value; When 1.0 ≤ K<1.2, an orange alarm is triggered, the servo hydraulic compensation displacement ΔD is started, and quick-setting slurry is injected into the displacement exceeding the standard area simultaneously, where ΔD=1.2×(D-0.7×D1); When K<1.0, a red alarm is triggered, the construction power supply is cut off, the sound and light alarm is activated, people within a radius of 50m are evacuated, and professional personnel are notified to carry out emergency repairs.

[0011] Further, the servo hydraulic compensation displacement ΔD is started, ΔD=1.2×(D-0.7×D1), where 1.2 is the rheological property correction factor of the dredger fill soil, and the servo hydraulic compensation completion time t≤30s; When D is greater than 0.7×D1, the dynamic warning module will directly trigger the start of the servo hydraulic compensation displacement ΔD.

[0012] Furthermore, the distributed fiber grating sensor is arranged along the longitudinal direction of the support body, and when the support body undergoes tensile or compressive deformation along its vertical direction, an axial strain signal F of the support body is collected; The MEMS inclination sensor is installed on the top of the support body, collects the measured angle θ of the support body perpendicular to the wall of the foundation pit, and then calculates the displacement D according to D = L×sinθ, where L is the height of the support body.

[0013] Due to the adoption of the above technical solution, the present invention has the following advantages compared with the prior art: 1. Through the collaboration of distributed fiber grating sensors (sampling frequency ≥ 10Hz) and MEMS inclination sensors, millisecond-level deformation signal capture is achieved, which is 360 times more efficient than traditional manual inspections (4-6 hours / time). It can effectively identify transient risks such as sudden subsidence and sideslip, and simultaneously collect five key parameters: axial strain, lateral displacement, soil pressure, pore water pressure and water level, solving the blind spot problem of single indicator monitoring.

[0014] 2. By calculating the comprehensive deformation value Q, and then introducing the pore water pressure change rate U3 and the water level change rate W3 to correct the safety factor K, the data fusion efficiency is improved, the data island problem is solved, and multi-level responses are triggered according to the K value to link the control equipment and personnel evacuation, thereby improving the early warning response efficiency and enhancing the engineering defense value of the deformation monitoring system under complex working conditions in the filling area. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of a deformation monitoring system for a vertical support body of a foundation pit in a filling area. DETAILED DESCRIPTION

[0016] The above and other technical contents, features and effects of the present invention are described in detail below with reference to the attached Figure 1 The detailed description of the embodiments will clearly show that the structural contents mentioned in the following embodiments are all based on the drawings in the specification.

[0017] Embodiment 1, on the basis of the existing technology, by calculating the comprehensive deformation value Q, and then introducing the pore water pressure change rate U3 and the water level change rate W3 to correct the safety factor K, the data fusion efficiency is improved, the data island problem is solved, and a multi-level response is triggered according to the K value, and the equipment and personnel evacuation are linked to improve the early warning response efficiency, and enhance the engineering defense value of the deformation monitoring system under complex working conditions in the filling area.

[0018] Specifically, it includes a multi-source signal acquisition module, a dynamic environment acquisition module and a fusion recognition module, a dynamic analysis module, and a dynamic warning module. The multi-source signal acquisition module adopts a distributed fiber grating sensor and a MEMS tilt sensor for coordinated deployment to obtain the axial strain signal F and the lateral displacement signal D of the support body in real time; The dynamic environment acquisition module integrates an earth pressure box, a pore water pressure gauge and a groundwater level sensor, and synchronously acquires earth pressure signals P, pore water pressure signals U and water level signals W; wherein the wavelength resolution of the distributed fiber grating sensor is ±5pm, the accuracy of the MEMS tilt sensor is ±0.02°, the earth pressure box has a range of 0-500kPa, the accuracy of the pore water pressure gauge is ±0.1kPa and the resolution of the groundwater level sensor is ±1cm; The fusion recognition module extracts the corresponding support body axial strain threshold F1, lateral displacement threshold D1, soil pressure threshold P1, pore water pressure threshold U1, and water level threshold W1 from the database, and calculates the comprehensive deformation value Q; The dynamic analysis module extracts the pore water pressure signal U2 and the water level signal W2 in adjacent time periods, calculates the pore water pressure change rate U3, and synchronously calculates the water level change rate W3; Calculate the support body safety value K, K = 1.5 ÷ [Q × (1 + 0.2 × U3 + 0.1 × W3)]; The dynamic warning module triggers a multi-level response according to the K value, linking the control equipment and personnel evacuation.

[0019] Furthermore, the multi-source signal acquisition module and the dynamic environment acquisition module add a unified timestamp to the corresponding sensor data through the Beidou dual-mode timing module, and the timing accuracy is ≤1ms. The corresponding sensors include distributed fiber grating sensors, MEMS inclination sensors, earth pressure boxes and pore water pressure gauges, among which the groundwater level sensor adopts independent clock synchronization with an error of ≤1s.

[0020] Furthermore, the fusion recognition module takes the support body axial strain signal F, lateral displacement signal D, soil pressure signal P, pore water pressure signal U and water level signal W with the same timestamp as a group of signals, and then extracts the corresponding support body axial strain threshold F1, lateral displacement threshold D1, soil pressure threshold P1 and pore water pressure threshold U1, water level threshold W1 in the database to calculate the comprehensive deformation value Q, Q=0.3×(F÷F1)+0.2×(D÷D1)+0.2×(P÷P1)+0.2×(U÷U1)+0.1×(W÷W1).

[0021] Furthermore, the dynamic analysis module extracts the pore water pressure signal U2 and the water level signal W2 in adjacent time, where the adjacent time is 5 minutes, calculates the pore water pressure change rate U3=|U1-U2|÷5, and simultaneously calculates the water level change rate W3=|W1-W2|÷5.

[0022] Furthermore, the dynamic early warning module triggers multi-level responses according to the K value, and coordinates the regulation of equipment and personnel evacuation. When 1.2 ≤ K < 1.5, a yellow alarm is triggered, and the precipitation rate is automatically reduced to 80% of the design value. When 1.0 ≤ K < 1.2, an orange alarm is triggered, the servo-hydraulic compensation displacement ΔD is started, and the quick-setting grout is synchronously injected into the area where the displacement exceeds the standard, where ΔD = 1.2×(D - 0.7×D1). When K < 1.0, a red alarm is triggered, the construction power supply is cut off and the sound and light alarm is started, the personnel within a 50m evacuation radius are evacuated, and professionals are notified for emergency repair.

[0023] Furthermore, the servo-hydraulic compensation displacement ΔD is started, ΔD = 1.2×(D - 0.7×D1), where 1.2 is the correction factor for the rheological characteristics of the dredger fill, and the completion time t of the servo-hydraulic compensation is ≤ 30s. When D is greater than 0.7×D1, the dynamic early warning module will directly trigger the start of the servo-hydraulic compensation displacement ΔD.

[0024] Furthermore, the distributed fiber Bragg grating sensors are arranged longitudinally along the support body. When the support body undergoes tensile or compressive deformation in the vertical direction, the axial strain signal F of the support body is collected. The MEMS inclinometer sensor is installed at the top of the support body to collect the measured angle θ of the support body perpendicular to the foundation pit wall surface, and then the displacement D is calculated according to D = L×sinθ, where L is the height of the support body.

[0025] Among them, Q is a normalized index reflecting the overall deformation risk of the support body, Q = 0.3×(F÷F1) + 0.2×(D÷D1) + 0.2×(P÷P1) + 0.2×(U÷U1) + 0.1×(W÷W1); Basis for weight distribution: Axial strain (F) and lateral displacement (D) have the greatest impact on the stability of the support body, and higher weights (0.3, 0.2) are assigned; Soil pressure (P) and pore water pressure (U) reflect the interaction between soils, and the weights are secondary (0.2 each); Water level (W) is an indirect factor with the lowest weight (0.1).

[0026] Normalization design: By using the measured value threshold to unify the dimensions of multi-source parameters, the problem of data islands is eliminated.

[0027] The safety value K of the support body, K is the dynamic instability risk coefficient, and the calculation formula of K follows the principle of "critical state soil mechanics", that is, the instability of the support body occurs when the effective stress path of the soil reaches the failure envelope. K = (static safety reserve) ÷ (dynamic deformation potential energy) = 1.5 ÷ [Q × (1 + 0.2 × U3 + 0.1 × W3)]; Engineering basis for the coefficient of 1.5: minimum safety reserve under static conditions, in line with the requirement of the Technical Code for Building Foundation Pit Support (JGJ120-2012) that the safety factor of the dredged fill foundation pit should be ≥ 1.4 (1.5 is a redundant design).

[0028] The significance of the change rate correction term: U3 (pore water pressure change rate) and W3 (water level change rate) reflect the accelerating effect of dynamic water load on soil rheology; The coefficients 0.2 and 0.1 are derived from the permeability characteristics of dredger fill: changes in pore water pressure are twice as sensitive to soil strength as changes in water level.

[0029] Reasonableness of the denominator structure: Q is the static deformation benchmark, and (1+0.2×U3+0.1×W3) is the dynamic water load correction factor. When U3 and W3 increase, the increase in the denominator leads to a decrease in K, which conforms to the logic of increasing risk.

[0030] When the present invention is used specifically, on the basis of the prior art, the multi-source signal acquisition module adopts the coordinated deployment of the distributed fiber grating sensor and the MEMS tilt sensor to obtain the axial strain signal F and the lateral displacement signal D of the support body in real time; The dynamic environment acquisition module integrates an earth pressure box, a pore water pressure gauge and a groundwater level sensor to synchronously acquire earth pressure signals P, pore water pressure signals U and water level signals W; The fusion recognition module takes the support body axial strain signal F, lateral displacement signal D, soil pressure signal P, pore water pressure signal U and water level signal W with the same timestamp as a group of signals, and then extracts the corresponding support body axial strain threshold F1, lateral displacement threshold D1, soil pressure threshold P1 and pore water pressure threshold U1, water level threshold W1 in the database to calculate the comprehensive deformation value Q, Q=0.3×(F÷F1)+0.2×(D÷D1)+0.2×(P÷P1)+0.2×(U÷U1)+0.1×(W÷W1); The dynamic analysis module extracts the pore water pressure signal U2 and the water level signal W2 in adjacent time periods, calculates the pore water pressure change rate U3, and synchronously calculates the water level change rate W3; Calculate the support body safety value K, K = 1.5 ÷ [Q × (1 + 0.2 × U3 + 0.1 × W3)]; The dynamic warning module triggers a multi-level response according to the K value, linking the control equipment and personnel evacuation. When 1.2 ≤ K<1.5, a yellow alarm is triggered, and the precipitation rate is automatically reduced to 80% of the design value; When 1.0 ≤ K < 1.2, an orange alert is triggered, and the servo hydraulic compensation displacement ΔD is started, and the quick-setting slurry is synchronously injected into the area where the displacement exceeds the standard, where ΔD = 1.2×(D - 0.7×D1); When K < 1.0, a red alert is triggered, the construction power supply is cut off and the sound and light alarm is started, the personnel within a radius of 50 m are evacuated, and professionals are notified for emergency repair. By calculating the comprehensive deformation value Q, and then introducing the pore water pressure change rate U3 and the water level change rate W3 to correct the safety factor K, and triggering multi-level responses according to the K value, the engineering defense value of the deformation monitoring system under complex working conditions in the reclamation area is improved.

[0031] The above is a further detailed description of the present invention in combination with specific embodiments, and it cannot be determined that the specific implementation of the present invention is only limited to this; for those skilled in the art of the present invention and related technical fields, based on the technical solution idea of the present invention, the expansion, operation methods, and data replacement should all fall within the protection scope of the present invention.

Claims

1. A deformation monitoring system for the vertical support body of a foundation pit in a hydraulic fill area, characterized in that It includes a multi-source signal acquisition module, a dynamic environment acquisition module, a fusion recognition module, a dynamic analysis module, and a dynamic warning module. The multi-source signal acquisition module uses a distributed fiber grating sensor and a MEMS tilt sensor to coordinate deployment to obtain the axial strain signal F and the lateral displacement signal D of the support body in real time; The dynamic environment acquisition module integrates an earth pressure box, a pore water pressure gauge and a groundwater level sensor to synchronously acquire earth pressure signals P, pore water pressure signals U and water level signals W; The fusion recognition module extracts the corresponding support body axial strain threshold F1, lateral displacement threshold D1, soil pressure threshold P1, pore water pressure threshold U1, and water level threshold W1 from the database, and calculates the comprehensive deformation value Q; The dynamic analysis module extracts the pore water pressure signal U2 and the water level signal W2 in adjacent time periods, calculates the pore water pressure change rate U3, and synchronously calculates the water level change rate W3; Calculate the support body safety value K, K = 1.5 ÷ [Q × (1 + 0.2 × U3 + 0.1 × W3)]; The dynamic warning module triggers a multi-level response according to the K value, linking the control equipment and personnel evacuation.

2. The deformation monitoring system for the vertical support body of the foundation pit in the hydraulic fill area according to claim 1, characterized in that, The multi-source signal acquisition module and the dynamic environment acquisition module add a unified timestamp to the corresponding sensor data through the Beidou dual-mode timing module, and the timing accuracy is ≤1ms. The corresponding sensors include distributed fiber grating sensors, MEMS inclination sensors, earth pressure boxes and pore water pressure gauges, among which the groundwater level sensor adopts independent clock synchronization with an error of ≤1s.

3. The deformation monitoring system for the vertical support body of the foundation pit in the hydraulic fill area according to claim 2, characterized in that, The fusion recognition module takes the support body axial strain signal F, lateral displacement signal D, soil pressure signal P, pore water pressure signal U and water level signal W with the same timestamp as a group of signals, and then extracts the corresponding support body axial strain threshold F1, lateral displacement threshold D1, soil pressure threshold P1 and pore water pressure threshold U1, water level threshold W1 in the database to calculate the comprehensive deformation value Q, Q=0.3×(F÷F1)+0.2×(D÷D1)+0.2×(P÷P1)+0.2×(U÷U1)+0.1×(W÷W1).

4. The deformation monitoring system for the vertical support body of the foundation pit in the hydraulic fill area according to claim 1, characterized in that, The dynamic analysis module extracts the pore water pressure signal U2 and the water level signal W2 in adjacent time, where the adjacent time is 5 minutes, calculates the pore water pressure change rate U3=|U1-U2|÷5, and simultaneously calculates the water level change rate W3=|W1-W2|÷5.

5. The deformation monitoring system for the vertical support body of the foundation pit in the hydraulic fill area according to claim 1, wherein The dynamic warning module triggers a multi-level response according to the K value, linking the control equipment and personnel evacuation. When 1.2 ≤ K < 1.5, a yellow alarm is triggered, and the precipitation rate is automatically reduced to 80% of the design value; When 1.0 ≤ K < 1.2, an orange alarm is triggered, the servo hydraulic compensation displacement ΔD is started, and quick-setting slurry is injected into the displacement exceeding the standard area simultaneously, where ΔD=1.2×(D-0.7×D1); When K < 1.0, a red alarm is triggered, the construction power supply is cut off, the sound and light alarm is activated, people within a radius of 50m are evacuated, and professional personnel are notified for emergency repairs.

6. The deformation monitoring system for the vertical support body of the foundation pit in the hydraulic fill area according to claim 5, characterized in that Start the servo-hydraulic compensation displacement ΔD, where ΔD = 1.2×(D - 0.7×D1), 1.2 is the rheological property correction factor of the dredger fill, and the servo-hydraulic compensation completion time t ≤ 30 s; When D is greater than 0.7×D1, the dynamic warning module will directly trigger the start of the servo-hydraulic compensation displacement ΔD.

7. A deformation monitoring system for a vertical support body of a foundation pit in a hydraulic fill area according to any one of claims 1-6, characterized in that, The distributed fiber Bragg grating sensors are arranged longitudinally along the support body. When the support body undergoes tensile or compressive deformation in its vertical direction, the axial strain signal F of the support body is collected; The MEMS inclination sensor is installed at the top of the support body to collect the measured angle θ of the support body perpendicular to the foundation pit wall surface, and then calculate the displacement D according to D = L×sinθ, where L is the height of the support body.

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