A comprehensive method for verifying the bearing capacity of steel sheet piles

Abstract

The invention discloses a method for comprehensively analyzing the safety and stability of steel sheet piles. The instruments mainly include an inclinometer, a total station and a strain gauge. The method for comprehensively analyzing the safety and stability of steel sheet piles adopts a variety of calculation methods and a large amount of manual data processing to establish a multivariable steel sheet pile safety and stability evaluation model, a soil displacement variation over time model, a steel sheet pile inclination variation over time model, and a steel sheet pile stress and strain variation over time model. The multivariable steel sheet pile safety and stability evaluation model can obtain a safety and stability boundary surface through a large amount of data and a corresponding loss function. The three time variation models can clearly know the current variation trend and predict the future variation trend. The method has the advantages of high efficiency, strong practicability, no specific environmental conditions, etc., and is widely applicable to comprehensive analysis of safety and stability and other issues.

Description

Technical Field

[0001] The present invention relates to the technical field of steel sheet pile deformation monitoring, and more specifically, to a method for comprehensively analyzing the safety and stability of steel sheet piles. Background Art

[0002] As a special type of steel sheet pile, the steel sheet pile is pressed into the ground by a pile driver and a vibrating hammer to form a continuous sheet pile wall, which serves as a temporary retaining and water retaining support structure for deep foundation pit excavation. Steel sheet piles have the advantages of high strength and rigidity, light structure, tight joints, good durability, good water tightness, simple construction, fast speed, good durability, small operation site occupation, and reusability. With the rapid development of my country's economy and the intensification of urbanization, the utilization rate of underground space has been greatly improved, and people are paying more and more attention to the use of underground space. Due to factors such as small ground space and construction site restrictions, the methods of unsupported maintenance and slope excavation have gradually been eliminated. With the development of urban economic construction, steel sheet piles, as a retaining structure, have been widely used in municipal administration, house construction, docks, industry, bridges, etc.

[0003] At present, the research on the stress of steel sheet piles is generally only focused on the construction method, support structure, and reinforcement of steel sheet piles. However, there are still great deficiencies in the research on the theory of stress stability and stress damage of steel sheet piles. There is no systematic method to judge the safety and stability of steel sheet piles. The research on the stress capacity of steel sheet piles has a profound impact on guiding on-site safe construction and eliminating potential risks in engineering. It can effectively and accurately reflect the actual situation of the stress of steel sheet piles, and a series of effective measures can be selectively taken according to the actual situation. It has a systematic and complete scientific basis, rather than simply reinforcing and supporting steel sheet piles.

[0004] With the increasing application of steel sheet piles in actual engineering projects, the production of steel sheet piles has also flourished. Some research has also been carried out on the stress problem of steel sheet piles, but the current research is far from meeting the needs of engineering production. There is an urgent need for a systematic method to systematically evaluate the safety and stability of steel sheet piles. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a comprehensive analysis method for the safety and stability of steel sheet piles, so as to solve the deficiencies in the safety and stability analysis of steel sheet piles in the prior art and provide a systematic and reliable analysis method.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows.

[0007] A method for comprehensively analyzing the safety and stability of steel sheet piles, the method for comprehensively analyzing the safety and stability of steel sheet piles is to analyze the stability of the steel sheet piles by monitoring the displacement of the soil, the overall inclination of the steel sheet piles and the deformation of the steel sheet piles; the instruments mainly include an inclinometer, a total station and a strain gauge; the soil displacement is composed of an inclinometer tube (soft), an inclinometer probe and a digital reader (inclinometer); the overall inclination of the steel sheet pile is composed of a reflector, a steel bar for fixing the reflector, a total station and a tripod; the steel sheet pile deformation includes a strain gauge, a signal transmission cable, a digital reader (strain gauge) and a strain gauge protection device; the strain gauge protection device includes an unloading soil Semi-conical device, shock-absorbing spring device, strain gauge shock-absorbing protection device, signal transmission cable protection device; the comprehensive analysis of steel sheet piles adopts a variety of calculation methods and a large amount of manual data processing to establish a multi-variable steel sheet pile safety and stability assessment model, a soil displacement time-varying model, a steel sheet pile inclination time-varying model, and a steel sheet pile stress-strain time-varying model; the multi-variable steel sheet pile safety and stability assessment model can obtain a safe and stable boundary surface through a large amount of data and corresponding loss functions, and the three time-varying models can show the current change trend and simulate and predict future change trends.

[0008] Preferably, the shock absorbing spring device comprises a piston rod, a spring, an upper top plate, a lower bottom plate, and three surrounding plates, wherein the spring surrounds the piston rod, the spring and the piston rod are connected to the upper top plate and the lower bottom plate at the same time, and the upper top plate and the lower bottom plate are not connected to the steel sheet piles.

[0009] Preferably, the lower base plate of the shock-absorbing spring device is connected to the soil unloading semi-cone, and the upper top plate is connected to the strain gauge shock-absorbing protection device.

[0010] Preferably, the strain gauge shock-absorbing protection device includes a shock-absorbing partition, a lower shock-absorbing pad, a shock-absorbing sponge, an upper shock-absorbing pad, and a rectangular protective cover. The strain gauge is connected to the steel sheet pile by welding, the shock-absorbing partition is connected to the steel sheet pile, the lower shock-absorbing pad is connected to the shock-absorbing partition, and the upper shock-absorbing pad and the lower shock-absorbing pad are respectively connected to the top and bottom surfaces of the shock-absorbing sponge.

[0011] Preferably, the signal transmission cable protection device includes a cylindrical shock-absorbing sponge sleeve, high-strength bolts, and a semicircular double-wing steel plate; the signal transmission cable is placed in the hole of the cylindrical shock-absorbing sponge protection sleeve, and the cylindrical shock-absorbing sponge sleeve is covered with a semicircular double-wing plate, and the semicircular double-wing plate and the cylindrical shock-absorbing sponge sleeve are fixed to the steel sheet piles with high-strength bolts.

[0012] Preferably, the multivariable steel sheet pile safety and stability assessment model adopts a variety of calculation methods and a large amount of manual data processing in the early stage. The safety and stability boundary surface is a three-dimensional space, which is obtained based on a large amount of measured data and a corresponding loss function. Each dimension represents an instrument measurement value. By simulating and statistically analyzing a large amount of measured data, using a loss function to reduce instrument and human errors, an empirical value that can define the safety and stability of steel sheet piles is drawn. Whether the steel sheet pile is safe and stable is defined based on the empirical value, and the safety and stability of the steel sheet pile can be warned.

[0013] Preferably, the safety and stability warning of the steel sheet pile is obtained based on a large amount of warning data and a loss function, and the three warning values ​​of red, orange and yellow can be distinguished and warned respectively.

[0014] Preferably, the method for comprehensively analyzing the safety and stability of steel sheet piles is characterized in that the soil displacement variation over time model, the steel sheet pile inclination variation over time model, and the steel sheet pile stress-strain variation over time model have time as the independent variable on the horizontal axis and the maximum soil displacement per unit time, the steel sheet pile inclination degree per unit time, and the steel sheet pile stress-strain per unit time as the dependent variables on the vertical axis. These three models can respectively display the current soil displacement, steel sheet pile inclination degree, and steel sheet pile stress-strain variation trends and simulate and predict future variation trends.

[0015] Preferably, the three time-varying models and the current measured values ​​or predicted values ​​are placed in a multivariable steel sheet pile safety and stability assessment model, which can assess the safety and stability of the current measured values ​​or predicted values ​​and provide corresponding conclusions.

[0016] The beneficial effects of the present invention are:

[0017] (1) A spring shock absorber is arranged between the unloading semi-cone and the strain gauge protection device to reduce the influence of the increased force of the unloading semi-cone on the strain gauge protection device as the steel sheet pile is driven into the soil layer. A piston rod is inserted in the middle of the spring, which has a double buffering effect and can effectively reduce the influence of the increased force on the strain gauge device as the steel sheet pile is inserted into the soil layer.

[0018] (2) The purpose of setting up the shock-absorbing partition is to better fix it with the steel sheet pile and reduce the vibration effect of the steel sheet pile on the strain gauge; the shock-absorbing pad and shock-absorbing sponge are to buffer the influence of the surrounding force on the strain gauge, better protect the strain gauge, and ensure that the measurement data has higher accuracy.

[0019] (3) A protective device is installed on the signal transmission cable, which includes a cylindrical shock-absorbing sponge sleeve, high-strength bolts, and a semicircular double-wing steel plate. A signal transmission cable installation hole is left on the cylindrical shock-absorbing sponge sleeve to better protect the signal transmission cable under the conditions of the steel sheet pile being inserted into the soil layer and the soil pressure, so that the data measurement can be carried out accurately.

[0020] (4) Based on the multivariable steel sheet pile safety and stability assessment model, the current measured values ​​and predicted values ​​can be directly evaluated for safety and stability, and an assessment conclusion can be given. This has scientific guiding significance for the safety of actual engineering construction.

[0021] (5) The models of soil displacement changing with time, steel sheet pile inclination changing with time, and steel sheet pile stress-strain changing with time can present the current changing trend of steel sheet pile stress-strain and simulate and predict the future changing trend. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention.

[0023] Figure 2 It is a schematic diagram of a top view of the device of the present invention.

[0024] Figure 3 It is a schematic diagram of the front view of the device of the present invention.

[0025] Figure 4 It is a schematic diagram of the rectangular protection device of the strain gauge of the present invention.

[0026] Figure 5 It is a schematic diagram of the protection device on the signal transmission cable of the present invention.

[0027] Figure 6 It is a schematic diagram of the soil deep horizontal displacement data acquisition system of the present invention.

[0028] Figure 7 It is a schematic diagram of the stress-strain data acquisition system of the steel sheet pile of the present invention.

[0029] Figure 8 It is a schematic diagram of the data collection system for the overall inclination of steel sheet piles according to the present invention.

[0030] Fig. 9 This is a schematic diagram of the multivariable steel sheet pile safety and stability assessment model of the present invention taking two variables as an example.

[0031] Fig.10 This is a schematic diagram of the model of steel sheet pile stress-strain variation with time as an example.

[0032] Description of Figure Numbers.

[0033] 1. Soil; 2. Inclinometer tube (soft); 3. Reflector fixing steel bar; 4. Reflector; 5. Signal transmission cable; 6. High-strength bolt; 7. Cylindrical shock-absorbing sponge; 8. Semicircular double-wing steel plate; 9. Rectangular protective cover mounting hole; 10. Shock-absorbing partition; 11. Lower shock-absorbing pad; 12. Shock-absorbing sponge; 13. Upper shock-absorbing pad; 14. Rectangular protective cover; 15. Strain gauge; 16. Upper top plate of spring device; 17. Piston rod; 18. Spring; 19 , lower base plate of spring device; 20. unloading semi-cone; 21. steel sheet pile; 22. signal transmission cable installation protection hole; 23. safe point; 24. unsafe point; 25. safety stability interface; 26. yellow warning interface; 27. orange warning interface; 28. red warning interface; 29. ​​inclinometer probe; 30. digital meter (inclinometer); 31. computer; 32. digital meter (strain gauge); 33. total station; 34. three-sided protective panels. DETAILED DESCRIPTION

[0034] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the connotation of the present invention, so the present invention is not limited to the specific implementation disclosed below.

[0035] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0037] like Figure 1As shown, the comprehensive analysis method for the safety and stability of steel sheet piles is to monitor soil displacement, the overall inclination of steel sheet piles and the deformation of steel sheet piles; the instruments mainly include inclinometers, total stations and strain gauges; the soil displacement is composed of an inclinometer tube 2 (soft), an inclinometer probe 29 and a digital reader (inclinometer) 30; the overall inclination of the steel sheet pile is composed of a reflector 3, a reflector fixing steel bar 4, a total station 33 and a tripod; the steel sheet pile deformation includes a strain gauge 15, a signal transmission cable 5, a digital reader (strain gauge) 32 and a strain gauge protection device; the strain gauge protection device includes a soil unloading semi-conical device 20, a shock absorbing spring device, a strain gauge shock absorbing protection device and a signal transmission cable protection device. The comprehensive analysis of steel sheet piles adopts a variety of calculation methods and a large amount of manual data processing to establish a multivariable steel sheet pile safety and stability assessment model, a soil displacement variation model over time, a steel sheet pile inclination variation model over time, and a steel sheet pile stress and strain variation model over time; the multivariable steel sheet pile safety and stability assessment model can obtain a safety and stability boundary surface through a large amount of data and corresponding loss functions, and the three time variation models can show the current variation trend and simulate and predict future variation trends.

[0038] Combination Figure 1 As shown, the shock absorbing spring device includes a piston rod 17, a spring 18, an upper top plate 16, a lower bottom plate 19, and three-sided enclosure plates 34. The spring 18 surrounds the piston rod 17, and the spring 18 and the piston rod 17 are connected to the upper top plate 16 and the lower bottom plate 19 at the same time, and the upper top plate 16 and the lower bottom plate 19 are not connected to the steel sheet piles 21.

[0039] Combination Figure 1 As shown, the lower bottom plate 19 of the shock absorbing spring device is connected to the soil unloading semi-cone 20, and the upper top plate 16 is connected to the strain gauge shock absorbing protection device.

[0040] like Figure 1 and Figure 5 As shown, the strain gauge shock-absorbing protection device includes a shock-absorbing partition 10, a lower shock-absorbing pad 11, a shock-absorbing sponge 12, an upper shock-absorbing pad 13, and a rectangular protective cover 14. The strain gauge 15 is connected to the steel sheet pile 21 by welding, the shock-absorbing partition 10 is connected to the steel sheet pile 21, the lower shock-absorbing pad 11 is connected to the shock-absorbing partition 10, and the upper shock-absorbing pad 11 and the lower shock-absorbing pad 13 are respectively connected to the top surface and the bottom surface of the shock-absorbing sponge 12.

[0041] In this embodiment, four shock-absorbing layers are arranged inside the strain gauge protection device, namely, a shock-absorbing diaphragm layer 10, a lower shock-absorbing cushion layer 11, a shock-absorbing sponge layer 12, and an upper shock-absorbing cushion layer 13. The shock-absorbing diaphragm 10, the lower shock-absorbing cushion layer 11, and the shock-absorbing sponge layer 12 are provided with strain gauge outer grooves and installation holes in the middle, which are convenient for the installation of the signal transmission cable 5 and the strain gauge 15. The triangular cross section of the unloading semi-cone 20 should be connected to the steel sheet pile 21.

[0042] like Figure 1 and Figure 5 As shown, the signal transmission cable protection device includes a cylindrical shock-absorbing sponge sleeve 7, a high-strength bolt 6, and a semicircular double-wing steel plate 8; the signal transmission cable 5 is placed in the signal transmission cable installation protection hole 22 in the middle of the cylindrical shock-absorbing sponge 7, and the cylindrical shock-absorbing sponge sleeve 7 is covered with a semicircular double-wing plate 8, and the semicircular double-wing plate 8 and the cylindrical shock-absorbing sponge sleeve 7 are fixed to the steel sheet pile 21 with high-strength bolts 6.

[0043] In this embodiment, the signal transmission cable 5 in the signal transmission cable protection device comes out from the strain gauge shock absorbing device installation hole 9 and is covered with a cylindrical shock absorbing sponge sleeve 7. The signal transmission cable 5 is on the top of the steel sheet pile 21, and sufficient length needs to be left to facilitate the signal transmission cable protection device to be connected to the strain gauge shock absorbing device as a whole and fixed on the steel sheet pile 21.

[0044] like Fig. 9 As shown, taking the two-dimensional model as an example, the multivariable steel sheet pile safety and stability assessment model adopts multiple calculation methods and a large amount of manual data processing in the early stage. The safety and stability boundary surface 25 is a three-dimensional space, which is obtained based on a large amount of measured data and the corresponding loss function. Each dimension represents an instrument measurement value. By simulating and statistically analyzing a large amount of measured data, using the loss function to reduce instrument and human errors, an empirical value that can define the safety and stability of the steel sheet pile is drawn. Based on the empirical value, it is determined whether the steel sheet pile is safe and stable, and an early warning of the safety and stability of the steel sheet pile can be issued.

[0045] like Fig. 9 As shown, the safety and stability warning of the steel sheet pile is obtained based on a large amount of warning data and loss function, and the three warning values ​​of red, orange and yellow can be distinguished and warned respectively.

[0046] Based on the above embodiment, in this embodiment, the specific calculation formula of the cross entropy loss function is as follows.

[0047] .

[0048] The loss function corresponding to the classification problem is 0-1 loss, which is a measure of classification accuracy. The estimated value for the correct classification is 0, otherwise it is 1.

[0049] .

[0050] Model 1: Safety and stability interface = 1; Yellow warning interface = 0.

[0051] Model 2: Yellow warning interface = 1; Orange warning interface = 0.

[0052] Model 3: Orange warning interface = 1; Red warning interface = 0.

[0053] To be more specific in this example, since we know the order of the security and stability interface, the yellow warning interface, the orange warning interface, and the red warning interface, we only need to assign values ​​in pairs in order. The assignment of each combination uses the cross entropy loss function. When the function value is the minimum, the corresponding boundary interface can be found.

[0054] like Fig.10 As shown in the figure, taking the model of stress-strain variation with time of steel sheet pile as an example, the model of soil displacement variation with time has time as the independent variable on the horizontal axis and the maximum soil displacement per unit time as the dependent variable on the vertical axis. This model can show the current variation trend of soil displacement and simulate and predict future variation trend.

[0055] In this embodiment, regarding the method of calculating the relationship between soil displacement and soil pressure, the corresponding finite element calculation formula can be referred to to perform calculation analysis and conclusion evaluation on the measured value data.

[0056] like Fig.10 As shown, taking the model of steel sheet pile stress-strain variation with time as an example, the model of steel sheet pile inclination variation with time has time as the independent variable on the horizontal axis and the inclination degree of steel sheet pile per unit time as the dependent variable on the vertical axis. This model can show the current variation trend of steel sheet pile inclination and simulate and predict future variation trend.

[0057] In this embodiment, the calculation method of the inclination degree of the steel sheet pile can refer to the incremental method of the pile wall support structure. The incremental method simulates the process of adding support points and excavation, and uses the load increment method to calculate the internal force and displacement increment generated by the incremental load of each construction step on the support structure. The final result is the superposition of the results of each incremental step. The calculation of the internal force and deformation of the support structure at each incremental step can be calculated by the structural mechanics method or the rod finite element method for the elastic foundation beam.

[0058] like Fig.10 As shown in the figure, the model of steel sheet pile stress-strain variation with time has time as the independent variable on the horizontal axis and the maximum value of steel sheet pile stress-strain per unit time as the dependent variable on the vertical axis. This model can show the current variation trend of steel sheet pile stress-strain and simulate and predict future variation trend.

[0059] Specifically, in this embodiment, the specific calculation formula for the stress and strain of the steel sheet pile is as follows.

[0060] ① Variable sensor calculation formula.

[0061] δ =Es·K·(f i 2 -f0 2 ).

[0062] Where: δ - steel sheet pile stress change value (KPa).

[0063] Es - Elastic modulus of steel (KPa) Carbon steel: 2.0-2.1x10 8 KPa.

[0064] K - Calibration factor of the strain sensor (10-6 / Hz2).

[0065] fi - Observation value of strain sensor at any moment (Hz).

[0066] f0 - Initial observation value (zero value) of the strain sensor.

[0067] ②Force sensor (rebar meter) calculation formula.

[0068] δ =K·(f i 2 -f0 2 ).

[0069] Where: δ - steel sheet pile stress change value (KPa).

[0070] K - Calibration factor of the force sensor (KPa / Hz2).

[0071] fi - Observed value of the force sensor at any moment (Hz).

[0072] f0 - Initial observed value of the force sensor (zero value).

[0073] like Fig. 9 and Fig.10 As shown, taking the time-varying model of stress and strain of steel sheet piles as an example, the three time-varying models and the current measured values ​​or predicted values ​​are placed in a safety and stability evaluation model based on multivariable steel sheet piles. The safety and stability of the current measured values ​​or predicted values ​​can be evaluated and corresponding conclusions can be given.

[0074] When the comprehensive analysis method for the safety and stability of steel sheet piles provided by the present invention is used, the protective device of the equipment should be installed in a relevant order. The three calculation methods described only need to calculate the data processing when establishing a multivariable steel sheet pile safety and stability assessment model in the early stage. After the data is analyzed for conclusions, the measured value data is input into the multivariable steel sheet pile safety and stability assessment model, and the corresponding conclusions are given. When the input data is sufficient, the cross entropy loss function can be used to depict the boundary surface. After the model has been simulated with a large amount of data, it is no longer necessary to use calculation formulas to process the data. It is only necessary to input measured values ​​or predicted values, and use model analysis to give corresponding conclusions. The corresponding formulas and methods are designed to make different data related to each other. Three different measured values ​​can be analyzed in one space, which can make the data more reasonable and reliable. Fig. 9 and Fig.10 The data of the safety and stability boundary surface, the safety point 23, the unsafe point 24 and the value points that change with time have no meaning. Fig. 9 This is a schematic diagram of a conceptual evaluation model using a two-dimensional plane as an example, and is not a multivariable steel sheet pile safety stability evaluation model of the present invention. Fig.10 It is a model of the stress and strain of steel sheet piles changing with time, which is similar to the model of the inclination of steel sheet piles changing with time and the model of the displacement of soil changing with time, but it is not shown in the patent. Fig. 9 and Fig.10 This is an example schematic diagram drawn for a better understanding of this patent.

[0075] In summary, the method for comprehensively analyzing the safety and stability of steel sheet piles provided by the present invention has the following beneficial effects.

[0076] (1) A spring shock absorber is arranged between the unloading semi-cone and the strain gauge protection device to reduce the influence of the increased force of the unloading semi-cone on the strain gauge protection device as the steel sheet pile is driven into the soil layer. A piston rod is inserted in the middle of the spring, which has a double buffering effect and can effectively reduce the influence of the increased force on the strain gauge device as the steel sheet pile is inserted into the soil layer.

[0077] (2) The purpose of setting up the shock-absorbing partition is to better fix it with the steel sheet pile and reduce the vibration effect of the steel sheet pile on the strain gauge; the shock-absorbing pad and shock-absorbing sponge are to buffer the influence of the surrounding force on the strain gauge, better protect the strain gauge, and ensure that the measurement data has higher accuracy.

[0078] (3) A protective device is installed on the signal transmission cable, which includes a cylindrical shock-absorbing sponge sleeve, high-strength bolts, and a semicircular double-wing steel plate. A signal transmission cable installation hole is left on the cylindrical shock-absorbing sponge sleeve to better protect the signal transmission cable under the conditions of the steel sheet pile being inserted into the soil layer and the soil pressure, so that the data measurement can be carried out accurately.

[0079] (4) Based on the multivariable steel sheet pile safety and stability assessment model, the current measured values ​​and predicted values ​​can be directly evaluated for safety and stability, and an assessment conclusion can be given. This has scientific guiding significance for the safety of actual engineering construction.

[0080] (5) The models of soil displacement changing with time, steel sheet pile inclination changing with time, and steel sheet pile stress-strain changing with time can present the current changing trend of steel sheet pile stress-strain and simulate and predict the future changing trend.

[0081] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0082] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for comprehensive analysis of the safety and stability of steel sheet piles, characterized in that: The method for comprehensively analyzing the safety and stability of steel sheet piles is to analyze the stability of the steel sheet piles by monitoring the displacement of the soil, the overall inclination of the steel sheet piles and the deformation of the steel sheet piles; the instruments mainly include an inclinometer, a total station and a strain gauge; the system for monitoring the displacement of the soil is composed of an inclinometer tube, an inclinometer probe and an inclinometer; the system for monitoring the overall inclination of the steel sheet piles is composed of a reflector, a steel bar for fixing the reflector, a total station and a tripod; the system for monitoring the deformation of the steel sheet piles includes a strain gauge, a signal transmission cable, a strain gauge and a strain gauge protection device; the strain gauge protection device includes a soil unloading semi-conical device, a shock absorbing spring device, a strain gauge The safety and stability evaluation model of steel sheet piles is based on a multivariable model of safety and stability of steel sheet piles, a model of soil displacement variation over time, a model of steel sheet pile inclination variation over time, and a model of steel sheet pile stress and strain variation over time. The multivariable model of safety and stability evaluation of steel sheet piles can obtain a safety and stability boundary surface through a large amount of data and a corresponding loss function. The three time variation models can show the current variation trend and simulate and predict the future variation trend. The shock-absorbing spring device includes a piston rod, a spring, an upper top plate, a lower bottom plate, and three surrounding plates; wherein the spring surrounds the piston rod, and the spring and the piston rod are simultaneously connected to the upper top plate and the lower bottom plate, and the upper top plate and the lower bottom plate are not connected to the steel sheet piles; The strain gauge shock-absorbing protection device includes a shock-absorbing partition, a lower shock-absorbing pad, a shock-absorbing sponge, an upper shock-absorbing pad, and a rectangular protective cover. The strain gauge is connected to the steel sheet pile by welding, the shock-absorbing partition is connected to the steel sheet pile, the lower shock-absorbing pad is connected to the shock-absorbing partition, and the upper shock-absorbing pad and the lower shock-absorbing pad are respectively connected to the top surface and the bottom surface of the shock-absorbing sponge.

2. A method for comprehensive analysis of the safety and stability of steel sheet piles according to claim 1, characterized in that: The lower bottom plate of the shock-absorbing spring device is connected to the soil unloading semi-circular cone, and the upper top plate is connected to the strain gauge shock-absorbing protection device.

3. A method for comprehensive analysis of the safety and stability of steel sheet piles according to claim 1, characterized in that: The signal transmission cable protection device includes a cylindrical shock-absorbing sponge sleeve, high-strength bolts, and a semicircular double-wing steel plate; the signal transmission cable is placed in the signal transmission cable installation protection hole in the middle of the cylindrical shock-absorbing sponge sleeve, and the cylindrical shock-absorbing sponge sleeve is covered with a semicircular double-wing steel plate, and the semicircular double-wing steel plate and the cylindrical shock-absorbing sponge sleeve are fixed to the steel sheet piles with high-strength bolts.

4. A method for comprehensive analysis of the safety and stability of steel sheet piles according to claim 1, characterized in that: The multivariable steel sheet pile safety and stability assessment model adopts a variety of calculation methods and a large amount of manual data processing in the early stage; the safety and stability boundary surface is a three-dimensional space, which is obtained based on a large amount of measured data and a corresponding loss function. Each dimension represents an instrument measurement value. By simulating and statistically analyzing a large amount of measured data and using a loss function to reduce instrument and human errors, an empirical value that can define the safety and stability of steel sheet piles is drawn. Based on the empirical value, it is determined whether the steel sheet piles are safe and stable, and an early warning of the safety and stability of the steel sheet piles can be issued.

5. A method for comprehensive analysis of the safety and stability of steel sheet piles according to claim 4, characterized in that: The safety and stability warning of steel sheet piles is calculated based on a large amount of warning data and loss functions, and can provide identification and warning for the three warning values ​​of red, orange and yellow respectively.

6. A method for comprehensive analysis of the safety and stability of steel sheet piles according to claim 1, characterized in that: The soil displacement variation over time model, the steel sheet pile inclination variation over time model, and the steel sheet pile stress-strain variation over time model have time as the independent variable on the horizontal axis and the maximum soil displacement per unit time, the steel sheet pile inclination degree per unit time, and the steel sheet pile stress-strain per unit time as the dependent variables on the vertical axis. These three models can respectively display the current soil displacement, steel sheet pile inclination degree, and steel sheet pile stress-strain variation trends and simulate and predict future variation trends.

7. According to claim 1, a method for comprehensive analysis of the safety and stability of steel sheet piles is characterized in that: The three time-varying models and the current measured values ​​or predicted values ​​are placed in a safety and stability assessment model based on multivariable steel sheet piles, which can evaluate the safety and stability of the current measured values ​​or predicted values ​​and give corresponding conclusions.

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