Deep foundation pit safety analysis method

Abstract

The invention discloses a deep foundation pit safety analysis method, and relates to the technical field of deep foundation pit safety analysis, and the method comprises the following analysis steps: outputting a comprehensive stress state value, a risk level evaluation value and a safety level of a deep foundation pit through a calculation and analysis module; according to the method, multiple factors such as the normal stress and the shear stress of the deep foundation pit in the x and y directions and the current elastic modulus of the supporting material are comprehensively considered, so that the comprehensive and accurate evaluation of the comprehensive stress state of the deep foundation pit is realized; and comprehensive and systematic evaluation of the risk level of the deep foundation pit is realized based on the comprehensive stress state value of the foundation pit, the geological condition score and the strength of the supporting structure, a plurality of risk thresholds are comprehensively considered, accurate judgment and early warning of the safety level of the deep foundation pit are realized, and when the stress state or the risk level of the deep foundation pit exceeds the risk thresholds, the deep foundation pit is protected from being damaged. The system can automatically send out an early warning signal to remind constructors to take measures in time for intervention and adjustment, so that the overall safety analysis of the deep foundation pit is more intelligent and timely.

Description

Technical Field

[0001] The invention relates to the technical field of deep foundation pit safety analysis, and in particular to a deep foundation pit safety analysis method. Background Art

[0002] In the process of urbanization, deep foundation pit projects are an important part of large-scale construction projects, and their safety is directly related to the quality of the entire project and the safety of personnel. However, the construction environment of deep foundation pits is complex and changeable, and multiple factors such as geological conditions, groundwater levels and construction technology are intertwined, making the safety assessment of deep foundation pits face huge challenges.

[0003] The existing deep foundation pit safety analysis methods for the comprehensive stress state assessment of deep foundation pits may rely on a single normal stress or shear stress indicator, while ignoring the complexity and multidimensionality of the stress state, which may result in inaccurate assessment results and make it difficult to fully reflect the stress state of the deep foundation pit. In addition, the risk assessment of deep foundation pits may only consider single factors such as geological conditions or support structure strength, while ignoring other possible influencing factors such as groundwater and construction technology, which leads to incomplete assessment results and makes it difficult to accurately reflect the risk level of deep foundation pits. In the existing technology, the safety level determination of deep foundation pits often relies on empirical judgment and simple threshold comparison, which lacks scientificity and accuracy, which may lead to unreliable safety level determination results and make it difficult to effectively guide the safety management of deep foundation pit construction. Summary of the invention

[0004] The purpose of the present invention is to provide a deep foundation pit safety analysis method to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a deep foundation pit safety analysis method, comprising the following analysis steps: Step I: collect stress values, geological condition information and support structure strength in the deep foundation pit through the data acquisition module, and input the collected data into the data processing module; Step II: The stress values, geological condition information and support structure strength in the deep foundation pit are sorted and cleaned through the data processing module, and the normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, the shear stress Sxy of the deep foundation pit in the x and y directions and the strength DDA of the support structure are output; Step III: The normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, the shear stress Sxy of the deep foundation pit in the x and y directions and the strength DDA of the supporting structure are calculated and analyzed by the module, and the comprehensive stress state value SVOP of the deep foundation pit, the risk level assessment value ROPF and the safety level are output; Step IV: Input the comprehensive stress state value SVOP, risk level assessment value ROPF and safety level of the deep foundation pit into the safety measures module. The safety measures module implements safety measures based on the safety level. After taking safety measures, the deep foundation pit continues to be monitored, and the safety measures are adjusted in time according to the monitoring results and changes in the safety level.

[0006] Optionally, the calculation and analysis module includes: a stress state synthesis sub-module, a risk assessment sub-module and a foundation pit safety level sub-module.

[0007] Optionally, the calculation formula of the stress state comprehensive submodule is as follows: ; in: SVOP refers to the value of comprehensive stress state of deep foundation pit; SVA refers to the normal stress of the deep foundation pit in the x direction, SVAA refers to the stress reference value, SVM refers to the ideal maximum normal stress, which indicates the maximum normal stress that the foundation pit bears under the most unfavorable conditions, SVB refers to the normal stress of the deep foundation pit in the y direction, Sxy refers to the shear stress of the deep foundation pit in the x and y directions, SP refers to the ideal maximum shear stress, which indicates the maximum shear stress that the foundation pit bears under the most unfavorable conditions, A1 refers to the influence constant related to the properties of the foundation pit support material, E refers to the current elastic modulus of the foundation pit support material, which indicates the stiffness of the material, that is, the ability of the material to resist deformation in the elastic deformation stage, EA refers to the reference elastic modulus, and SVA-SVAA refers to the degree of deviation of the stress in the x direction of the deep foundation pit from the reference value; The processing process of the stress state comprehensive submodule is as follows: the normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, and the shear stress Sxy of the deep foundation pit in the x and y directions are input into the stress state comprehensive submodule, and the comprehensive stress state value SVOP of the deep foundation pit is output based on the stress reference value SVAA and the ideal maximum normal stress SVM.

[0008] Optionally, the calculation formula of the risk assessment submodule is as follows: ; in: ROPF refers to the risk level assessment value; RA refers to the weight coefficient of SVOP, RB refers to the weight coefficient of GGA, GGA refers to the geological condition score, GGAM refers to the maximum value of the geological condition score, RC refers to the weight coefficient of DDA, DDA refers to the strength of the support structure, DP refers to the reference value of the strength of the support structure, GGA / GGAM refers to the ratio of the geological condition score to the maximum score; The processing process of the risk assessment submodule is as follows: the comprehensive stress state value SVOP of the deep foundation pit and the strength DDA of the support structure are input into the risk assessment submodule, and the risk level assessment value ROPF is output based on the geological condition score GGA and the reference value DP of the support structure strength.

[0009] Optionally, the calculation formula of the foundation pit safety level submodule is as follows: Security Level ;

[0010] in: ROAA refers to the risk threshold value one with a value of 0.4, which means the critical value of the lower risk level. Below this value, the security risk is considered controllable; ROBB refers to the risk threshold value 2, which is 0.75; SVBB refers to the critical threshold of the comprehensive stress state, which is 0.65, indicating that the comprehensive stress state exceeds When this value is exceeded, special attention should be paid to the stability of the deep foundation pit; The processing process of the foundation pit safety level submodule is as follows: the comprehensive stress state value SVOP and the risk level assessment value ROPF of the deep foundation pit are input into the foundation pit safety level submodule, and based on the risk threshold 1 ROAA, the risk threshold 2 ROBB and the comprehensive stress state critical threshold SVBB, the safety level 1, safety level 2 and safety level 3 are output.

[0011] Optionally, the security measure module is specifically: At safety level 1, the deep foundation pit is in a low-risk state; Treatment measures: Continue to proceed according to the normal construction plan, but maintain regular monitoring and inspection of the stability of the deep foundation pit; At safety level 2, the deep foundation pit is at medium risk; Treatment measures: Take additional monitoring and preventive measures, that is, increase the number of monitoring points to improve the monitoring frequency, strengthen the inspection and maintenance of the support structure, and adjust the construction plan to reduce the impact on the stability of the deep foundation pit; At safety level 3, the deep foundation pit is at high risk; Treatment measures: Immediately stop construction activities and conduct a comprehensive safety assessment, take emergency support measures, that is, add temporary support structures or reinforce existing support structures, and organize an expert team to discuss and formulate a detailed safety treatment plan, and ensure that all construction personnel understand and comply with relevant safety regulations.

[0012] Optionally, the data acquisition module uses stress sensors, geological exploration equipment and support structure strength testing equipment; The geological exploration equipment is specifically a geological radar and a drilling equipment, which is used to analyze geological conditions to evaluate the geological condition score; The support structure strength testing equipment is specifically a pressure sensor and a tensile testing machine, which are used to measure the support structure to output the strength DDA of the support structure.

[0013] Optionally, the stress sensors are installed on the side walls and the bottom of the deep foundation pit, and the normal stress and shear stress of the deep foundation pit in the x and y directions are measured by the stress sensors.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention outputs the comprehensive stress state value of the deep foundation pit through the stress state comprehensive submodule. This submodule comprehensively considers the normal stress, shear stress, maximum normal stress and maximum shear stress of the deep foundation pit in the x and y directions, and combines the ratio of the current elastic modulus to the reference elastic modulus to evaluate the comprehensive stress state of the deep foundation pit. This submodule can fully reflect the stress state of the deep foundation pit, and considers the change of elastic modulus to make the evaluation result more accurate. The calculation of the comprehensive stress state value of the deep foundation pit provides intuitive data of the stress state of the deep foundation pit, which helps to judge whether it is within a safe range. The stress state change of the deep foundation pit can be predicted through the SVOP change trend, providing a basis for subsequent preventive measures.

[0015] 2. The present invention outputs a risk level assessment value through a risk assessment submodule. This submodule quantitatively assesses the risk level of a deep foundation pit by combining comprehensive stress state, geological conditions, support structure strength and other influencing factors. This submodule covers multiple influencing factors to make the assessment result more comprehensive. The quantitative assessment of the risk level of a deep foundation pit provides decision makers with clear risk warnings. Through changes in the risk level assessment value, potential safety hazards can be discovered in time to avoid accidents, and more reasonable risk management measures can be formulated in combination with historical data and experience.

[0016] 3. The present invention outputs three safety levels through the foundation pit safety level submodule. The foundation pit safety level submodule and the safety measures module cooperate with each other to determine the safety level of the deep foundation pit based on the comprehensive stress state value and risk level assessment value of the deep foundation pit and make early warning measures in time. This method can intuitively reflect the safety status of the deep foundation pit and provide clear guidance for decision makers. When the safety level is low, measures such as strengthening support and adjusting construction plans can be taken to improve safety. When the safety level is high, it is necessary to pay close attention to changes in the deep foundation pit and take timely measures to prevent accidents.

[0017] 4. The present invention iterates the stress reference value in the stress state comprehensive submodule through the risk level assessment value, so that the comprehensive stress state value of the deep foundation pit and the risk level assessment value are continuously iterated and optimized. The stress reference value is iteratively adjusted through the risk level assessment value to establish a dynamic adjustment and feedback mechanism. With the progress of deep foundation pit construction and changes in geological conditions, the risk level will be updated in real time and the value of the stress reference value will be adjusted accordingly to ensure the accuracy and timeliness of the safety assessment. This iterative form updates the risk level assessment value in real time and adjusts the value of the stress reference value accordingly, which can timely discover potential safety hazards and take corresponding early warning and prevention and control measures to avoid accidents. The iterative analysis results provide an important basis for construction decisions, such as determining a reasonable excavation sequence, support timing and monitoring frequency, etc., to ensure the smooth progress of the construction process. Compared with the existing methods, this iterative method not only takes into account the stress state of the deep foundation pit. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart of the steps of this deep foundation pit safety analysis method; Figure 2 This is the overall structural diagram of the deep foundation pit safety analysis method; Figure 3 This is a schematic diagram of the structure of the calculation and analysis module of this deep foundation pit safety analysis method. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Regarding this deep foundation pit safety analysis method, it is different from the existing deep foundation pit safety analysis method. The existing safety analysis method often relies on a single normal stress or shear stress indicator for the comprehensive stress state assessment of the deep foundation pit, ignoring the complexity and multidimensionality of the stress state, which leads to inaccurate assessment results and difficulty in fully reflecting the stress state of the deep foundation pit. The risk assessment of the deep foundation pit may only consider a single factor such as geological conditions, ignoring other possible influencing factors, which leads to incomplete assessment results and difficulty in accurately reflecting the risk level of the deep foundation pit. The safety level determination of the deep foundation pit often relies on empirical judgment or simple threshold comparison, which lacks scientificity and accuracy. This leads to unreliable safety level determination results and difficulty in effectively guiding the safety management of deep foundation pit construction. The module of this deep foundation pit safety analysis system method realizes a comprehensive evaluation of the comprehensive stress state of the deep foundation pit by comprehensively considering multiple factors such as the normal stress, shear stress, maximum normal stress, maximum shear stress and current elastic modulus in the x and y directions of the deep foundation pit. This method comprehensively considers factors such as the comprehensive stress state, geological condition score and support structure strength to realize a comprehensive evaluation of the risk level of the deep foundation pit. This method comprehensively considers the risk level and comprehensive stress state, as well as multiple thresholds and warning function values, to achieve accurate judgment and early warning of the safety level of the deep foundation pit.

[0021] For example, see Figures 1 to 3 , this implementation provides a deep foundation pit safety analysis method, including the following analysis steps: Step I: collect stress values, geological condition information and support structure strength in the deep foundation pit through the data acquisition module, and input the collected data into the data processing module; Step II: The stress values, geological condition information and support structure strength in the deep foundation pit are sorted and cleaned through the data processing module, and the normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, the shear stress Sxy of the deep foundation pit in the x and y directions and the strength DDA of the support structure are output; Step III: The normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, the shear stress Sxy of the deep foundation pit in the x and y directions and the strength DDA of the supporting structure are calculated and analyzed by the module, and the comprehensive stress state value SVOP of the deep foundation pit, the risk level assessment value ROPF and the safety level are output; Step IV: Input the comprehensive stress state value SVOP, risk level assessment value ROPF and safety level of the deep foundation pit into the safety measures module. The safety measures module implements safety measures based on the safety level. After taking the safety measures, the deep foundation pit is continuously monitored. According to the monitoring results and the changes in the safety level, the safety measures are adjusted in time. The calculation and analysis module includes: stress state comprehensive submodule, risk assessment submodule and foundation pit safety level submodule.

[0022] In this embodiment: multiple submodules in this calculation and analysis module are interrelated and complementary in the deep foundation pit safety analysis. The comprehensive stress state SVOP obtained by running the stress state comprehensive submodule is one of the inputs of the risk assessment submodule. The risk level ROPF calculated by the risk assessment submodule and the SVOP calculated by the stress state comprehensive submodule are used together as the input of the foundation pit safety level submodule to finally determine the safety level of the deep foundation pit or issue an early warning. Computer-aided analysis can integrate the input data required by the three groups of submodules to ensure the accuracy and consistency of the data. By real-time monitoring and recording of various data of the deep foundation pit, reliable data support is provided for the calculation of multiple submodules. Computer-aided analysis can realize the visualization of data, making the evaluation results more intuitive and easy to understand. It helps decision makers make quick judgments and combines the calculation results of multiple sub-modules with the actual situation to provide scientific decision support for decision makers to ensure the safe construction of deep foundation pits. Multiple groups of sub-modules comprehensively consider the stress state, geological conditions, support structure strength and other influencing factors of deep foundation pits to make the evaluation results more comprehensive and accurate. By setting multiple risk thresholds, the three groups of sub-modules can realize the refined evaluation of the safety status of deep foundation pits and improve the accuracy and timeliness of early warning. With the help of computer-aided analysis, the three groups of sub-modules can be quickly calculated and visualized, which improves the evaluation efficiency and accuracy and reduces the cost of manual calculation and data processing. The three groups of sub-modules have high flexibility and adaptability and can be adjusted and optimized according to actual conditions to meet the safety analysis needs of different deep foundation pits.

[0023] See also Figures 1 to 3 , the processing process of the stress state synthesis submodule is as follows: ; in: SVOP refers to the value of comprehensive stress state of deep foundation pit; SVA refers to the normal stress of the deep foundation pit in the x direction, SVAA refers to the stress reference value, SVM refers to the ideal maximum normal stress, which indicates the maximum normal stress that the foundation pit bears under the most unfavorable conditions, SVB refers to the normal stress of the deep foundation pit in the y direction, Sxy refers to the shear stress of the deep foundation pit in the x and y directions, SP refers to the ideal maximum shear stress, which indicates the maximum shear stress that the foundation pit bears under the most unfavorable conditions, A1 refers to the influence constant related to the properties of the foundation pit support material, E refers to the current elastic modulus of the foundation pit support material, which indicates the stiffness of the material, that is, the ability of the material to resist deformation in the elastic deformation stage, EA refers to the reference elastic modulus, and SVA-SVAA refers to the degree of deviation of the stress in the x direction of the deep foundation pit from the reference value; The processing process of the stress state comprehensive submodule is as follows: the normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, and the shear stress Sxy of the deep foundation pit in the x and y directions are input into the stress state comprehensive submodule, and the comprehensive stress state value SVOP of the deep foundation pit is output based on the stress reference value SVAA and the ideal maximum normal stress SVM.

[0024] In this embodiment: the supporting structure of the deep foundation pit is usually composed of a variety of materials, steel: used to make supporting structures such as support beams and steel sheet piles, with a pressure of 200-210 GPa; concrete: used to make underground continuous walls, internal supports, etc., with a pressure of 20-30 GPa; soil: natural soil or backfill soil around the deep foundation pit; This submodule evaluates the comprehensive stress state of the deep foundation pit by comprehensively considering the normal stress, shear stress, reference stress value, maximum normal stress and maximum shear stress in the x and y directions, combined with the ratio of the current elastic modulus to the reference elastic modulus. This submodule comprehensively reflects the stress state of the deep foundation pit and takes into account the change of the elastic modulus, making the evaluation result more accurate. The calculation of SVOP provides intuitive data on the stress state of the deep foundation pit, which helps to determine whether it is within a safe range. The change trend of SVOP can be used to predict the change of the stress state of the deep foundation pit, providing a basis for taking preventive measures.

[0025] See also Figures 1 to 3 ,The processing process of the risk assessment submodule is as follows: ; in: ROPF refers to the risk level assessment value; RA refers to the weight coefficient of SVOP, RB refers to the weight coefficient of GGA, GGA refers to the geological condition score, GGAM refers to the maximum value of the geological condition score, RC refers to the weight coefficient of DDA, DDA refers to the strength of the support structure, DP refers to the reference value of the strength of the support structure, GGA / GGAM refers to the ratio of the geological condition score to the maximum score; The processing process of the risk assessment submodule is as follows: the comprehensive stress state value SVOP of the deep foundation pit and the strength DDA of the support structure are input into the risk assessment submodule, and the risk level assessment value ROPF is output based on the geological condition score GGA and the reference value DP of the support structure strength.

[0026] In this embodiment, the geological condition score GGA is a comprehensive evaluation index used to quantify the impact of the geological conditions in the area where the deep foundation pit is located on construction safety. The scoring standard can be set based on multiple geological factors, such as soil stability, rock layer distribution, groundwater level, adverse geological phenomena, etc. The specific analysis is as follows: Soil stability: Evaluate soil stability based on soil type, thickness, density, internal friction angle, cohesion and other parameters. The higher the stability, the higher the score. The score range is 0-20 points. Rock layer distribution: evaluates the type, hardness, integrity of the rock layer and the interaction between the rock layer and the soil layer. The harder and more complete the rock layer, the higher the score. The score range is 0-30 points. Groundwater level: assess the depth, range of change and impact of groundwater level on construction. The lower the groundwater level and the smaller the change, the higher the score, with a score range of 0-20 points; Adverse geological phenomena: assess whether there are adverse geological phenomena such as landslides, debris flows, and karst caves, as well as the potential threat these phenomena pose to construction safety. The higher the score, the greater the absence of adverse geological phenomena or the smaller the threat. The score range is 0-30 points; In summary, the geological condition score GGA is the sum of the scores of each factor, that is: GGA = soil stability score + rock distribution score + groundwater level score + adverse geological phenomenon score; This submodule quantitatively evaluates the risk level of deep foundation pits by combining comprehensive stress state, geological conditions, support structure strength and other influencing factors. This submodule covers a variety of influencing factors, making the evaluation results more comprehensive, quantifying the risk level of deep foundation pits, and providing clear risk warnings for decision makers. Through the changes in ROPF, potential safety hazards can be discovered in time to avoid accidents. In addition, more reasonable risk management measures can be formulated in combination with historical data and experience. It is worth noting that the stress reference value SVAA in the stress state comprehensive submodule is iterated based on the risk level assessment value ROPF, so that the deep foundation pit comprehensive stress state value SVOP and the risk level assessment value ROPF are continuously iterated and optimized, thereby improving the accuracy of the whole day's calculation and analysis. The processing process is as follows: first: ; Second: Set the iteration termination condition: Termination condition 1: The number of iterations is 100; Termination condition 2: |SVAA new -SVAA old |<0.001; in: SVAAnew refers to the updated stress reference value; SVAAold refers to the stress baseline value before the update, α refers to the learning rate, Refers to the partial derivative of ROPF with respect to SVAA, indicating the rate at which ROPF changes with SVAA; In this embodiment: SVAA is iterated through ROPF, and a dynamic adjustment and feedback mechanism is established. This means that as the deep foundation pit construction progresses and the geological conditions change, the risk level ROPF will be updated in real time, and the value of SVAA will be adjusted accordingly, so as to ensure the accuracy and timeliness of the safety assessment. The iterative process can gradually approach the optimal solution, that is, find the SVAA value that minimizes the risk level ROPF, which greatly improves the accuracy of the safety assessment and helps to more accurately predict and prevent potential safety risks. The iterative method can adapt to the safety analysis of deep foundation pits under different geological conditions, construction methods and safety requirements. By adjusting the iteration parameters and convergence conditions, it can flexibly respond to various complex situations. Through iterative analysis, the optimal support structure parameters, such as the diameter, spacing and burial depth of the support piles, can be found, so as to optimize the support design and improve the stability of the deep foundation pit. This iterative form updates the risk level ROPF in real time and adjusts the value of SVAA accordingly. Potential safety hazards can be discovered in time, and corresponding early warning and prevention and control measures can be taken to avoid accidents. The results of the iterative analysis can provide an important basis for construction decisions, such as determining Reasonable excavation sequence, support timing and monitoring frequency, etc., ensure the smooth progress of the construction process. Compared with the traditional method, this iterative method not only considers the stress state of the deep foundation pit, but also comprehensively considers the impact of multiple factors such as geological conditions and construction methods on safety, thereby improving the comprehensiveness and accuracy of the analysis. Through the iterative algorithm, the SVAA value that minimizes the risk level can be efficiently solved, avoiding the tedious trial calculation and optimization process in the traditional method. This iterative method is easy to combine with the automatic monitoring system and the intelligent decision-making system to realize the automation and intelligence of the deep foundation pit safety analysis, and improve the analysis efficiency and accuracy. ROPF is an important indicator for the safety assessment of deep foundation pits. It comprehensively reflects the impact of multiple factors such as the stress state, geological conditions, and construction methods of deep foundation pits on safety. SVAA, as a key parameter in the stress state comprehensive submodule, directly affects the calculation result of the comprehensive stress state SVOP, and then affects the size of the risk level ROPF. Therefore, by continuously adjusting the value of SVAA, the safety state of the deep foundation pit is optimized. This iterative process reflects the close correlation and mutual influence between ROPF and SVAA.

[0027] See also Figures 1 to 3 ,The processing process of the foundation pit safety level submodule is as follows: Security Level ; in: ROAA refers to the risk threshold value one with a value of 0.4, which means the critical value of the lower risk level. Below this value, the security risk is considered controllable; ROBB refers to the risk threshold value 2, which is 0.75; SVBB refers to the critical threshold of the comprehensive stress state, which is 0.65, indicating that the comprehensive stress state exceeds When this value is exceeded, special attention should be paid to the stability of the deep foundation pit; The processing process of the foundation pit safety level submodule is as follows: the comprehensive stress state value SVOP and the risk level assessment value ROPF of the deep foundation pit are input into the foundation pit safety level submodule, and based on the risk threshold 1 ROAA, the risk threshold 2 ROBB and the critical threshold SVBB of the comprehensive stress state, the safety level 1, safety level 2 and safety level 3 are output; The security measures modules are as follows: At safety level 1, the deep foundation pit is in a low-risk state; Treatment measures: Continue to proceed according to the normal construction plan, but maintain regular monitoring and inspection of the stability of the deep foundation pit; At safety level 2, the deep foundation pit is at medium risk; Treatment measures: Take additional monitoring and preventive measures, that is, increase the number of monitoring points to improve the monitoring frequency, strengthen the inspection and maintenance of the support structure, and adjust the construction plan to reduce the impact on the stability of the deep foundation pit; At safety level 3, the deep foundation pit is at high risk; Treatment measures: Immediately stop construction activities and conduct a comprehensive safety assessment, take emergency support measures, that is, add temporary support structures or reinforce existing support structures, and organize an expert team to discuss and formulate a detailed safety treatment plan, and ensure that all construction personnel understand and comply with relevant safety regulations.

[0028] In this embodiment: the foundation pit safety level submodule and the safety measures module cooperate with each other to determine the safety level of the deep foundation pit and take early warning measures in a timely manner based on the deep foundation pit comprehensive stress state value SVOP and the risk level assessment value ROPF. This method can intuitively reflect the safety status of the deep foundation pit and provide clear guidance for decision makers. When the safety level is low, measures such as strengthening support and adjusting construction plans can be taken to improve safety. When the safety level is high, it is necessary to pay close attention to changes in the deep foundation pit and take timely measures to prevent accidents.

[0029] In the specific implementation process, a variety of sub-modules in this method are used to form a deep foundation pit safety analysis system. The normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, and the shear stress Sxy of the deep foundation pit in the x and y directions are input into the stress state comprehensive sub-module to output the comprehensive stress state value SVOP of the deep foundation pit. This sub-module comprehensively considers the normal stress and shear stress of the deep foundation pit in the x and y directions, as well as the maximum normal stress and maximum shear stress, and combines the ratio of the current elastic modulus to the reference elastic modulus to evaluate the comprehensive stress state of the deep foundation pit. This sub-module can comprehensively reflect the stress state of the deep foundation pit, and considers the change of elastic modulus to make the evaluation result more accurate. The calculation of SVOP provides intuitive data of the stress state of the deep foundation pit, which helps to judge whether it is within the safety range. The change trend of SVOP can predict the change of the stress state of the deep foundation pit, providing a basis for taking preventive measures.

[0030] The comprehensive stress state value SVOP of the deep foundation pit and the strength DDA of the support structure are input into the risk assessment submodule, and the risk level assessment value ROPF is output. This submodule quantitatively evaluates the risk level of the deep foundation pit by combining the comprehensive stress state, geological conditions, support structure strength and other influencing factors. This submodule covers a variety of influencing factors to make the assessment results more comprehensive. The risk level of the deep foundation pit is quantitatively assessed to provide decision makers with clear risk warnings. Through the changes in ROPF, potential safety hazards can be discovered in time to avoid accidents, and more reasonable risk management measures can be formulated in combination with historical data and experience.

[0031] The comprehensive stress state value SVOP and the risk level assessment value ROPF of the deep foundation pit are input into the foundation pit safety level submodule, and the safety level 1, safety level 2 and safety level 3 are output. The foundation pit safety level submodule and the safety measures module cooperate with each other to determine the safety level of the deep foundation pit based on the comprehensive stress state value SVOP and the risk level assessment value ROPF of the deep foundation pit, and make early warning measures in time. This method can intuitively reflect the safety status of the deep foundation pit and provide clear guidance for decision makers. When the safety level is low, measures such as strengthening support and adjusting the construction plan can be taken to improve safety. When the safety level is high, it is necessary to pay close attention to the changes in the deep foundation pit and take timely measures to prevent accidents.

[0032] Based on the risk level assessment value ROPF, the stress reference value SVAA in the stress state comprehensive submodule is iterated, so that the comprehensive stress state value SVOP of the deep foundation pit and the risk level assessment value ROPF are continuously iterated and optimized. By iterating SVAA through ROPF, a dynamic adjustment and feedback mechanism is established, which means that with the progress of deep foundation pit construction and changes in geological conditions, the risk level ROPF will be updated in real time and the value of SVAA will be adjusted accordingly to ensure the accuracy and timeliness of the safety assessment. This iterative form updates the risk level ROPF in real time and adjusts the value of SVAA accordingly, which can timely discover potential safety hazards and take corresponding early warning and prevention and control measures to avoid accidents. The iterative analysis results can provide important basis for construction decisions, such as determining a reasonable excavation sequence, support timing and monitoring frequency, etc., to ensure the smooth progress of the construction process. Compared with traditional methods, this iterative method not only considers the stress state of the deep foundation pit.

[0033] In summary, this method enables multiple sub-modules to cooperate with each other in calculation, and can also perform overall cycles and iterations, so that the overall system has the effect of automatic optimization and updating, and thus has better adaptability.

[0034] Example 2: Please refer to Figure 1 , Figure 2 and Figure 3 ,The data acquisition module uses stress sensors, geological exploration equipment, and support structure strength testing equipment; Stress sensors are installed on the side walls and bottom of the deep foundation pit, and the normal stress and shear stress of the deep foundation pit in the x and y directions are measured by the stress sensors; Geological exploration equipment specifically includes geological radar and drilling equipment, which are used to analyze geological conditions to assess geological condition scores; The support structure strength testing equipment is specifically a pressure sensor and a tensile testing machine, which are used to measure the support structure to output the strength DDA of the support structure.

[0035] In this embodiment: geological exploration equipment should be installed around and at the bottom of the deep foundation pit for exploration to obtain geological condition information. The support structure strength test should be carried out on key parts of the support structure, such as support piles and anchor cables. The various sensors and detection equipment used by the data acquisition module can monitor and upload the safety and stability status of the deep foundation pit in real time, and calculate and analyze the safety performance of the deep foundation pit in a timely and real-time manner, so as to achieve the purpose of dynamic and real-time monitoring of the safety of the deep foundation pit through timely updated data.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A deep foundation pit safety analysis method, characterized by: The analysis steps include: Step I: collect stress values, geological condition information and support structure strength in the deep foundation pit through the data acquisition module, and input the collected data into the data processing module; Step II: The stress values, geological condition information and support structure strength in the deep foundation pit are sorted and cleaned through the data processing module, and the normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, the shear stress Sxy of the deep foundation pit in the x and y directions and the strength DDA of the support structure are output; Step III: The normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, the shear stress Sxy of the deep foundation pit in the x and y directions and the strength DDA of the supporting structure are calculated and analyzed by the module, and the comprehensive stress state value SVOP of the deep foundation pit, the risk level assessment value ROPF and the safety level are output; Step IV: Input the comprehensive stress state value SVOP, risk level assessment value ROPF and safety level of the deep foundation pit into the safety measures module. The safety measures module implements safety measures based on the safety level. After taking safety measures, the deep foundation pit continues to be monitored, and the safety measures are adjusted in time according to the monitoring results and changes in the safety level.

2. The deep foundation pit safety analysis method according to claim 1, characterized in that: The calculation and analysis module includes: a stress state synthesis submodule, a risk assessment submodule and a foundation pit safety level submodule.

3. The deep foundation pit safety analysis method according to claim 2 is characterized in that: The calculation formula of the stress state comprehensive submodule is as follows: ； in: SVOP refers to the value of comprehensive stress state of deep foundation pit; SVA refers to the normal stress of the deep foundation pit in the x direction, SVAA refers to the stress reference value, SVM refers to the ideal maximum normal stress, which indicates the maximum normal stress that the foundation pit bears under the most unfavorable conditions, SVB refers to the normal stress of the deep foundation pit in the y direction, Sxy refers to the shear stress of the deep foundation pit in the x and y directions, SP refers to the ideal maximum shear stress, which indicates the maximum shear stress that the foundation pit bears under the most unfavorable conditions, A1 refers to the influence constant related to the properties of the foundation pit support material, E refers to the current elastic modulus of the foundation pit support material, which indicates the stiffness of the material, that is, the ability of the material to resist deformation in the elastic deformation stage, EA refers to the reference elastic modulus, and SVA-SVAA refers to the degree of deviation of the stress in the x direction of the deep foundation pit from the reference value; The processing process of the stress state comprehensive submodule is as follows: the normal stress SVA of the deep foundation pit in the x direction, the normal stress SVB of the deep foundation pit in the y direction, and the shear stress Sxy of the deep foundation pit in the x and y directions are input into the stress state comprehensive submodule, and the comprehensive stress state value SVOP of the deep foundation pit is output based on the stress reference value SVAA and the ideal maximum normal stress SVM.

4. The deep foundation pit safety analysis method according to claim 3 is characterized in that: The calculation formula of the risk assessment submodule is as follows: ； in: ROPF refers to the risk level assessment value; RA refers to the weight coefficient of SVOP, RB refers to the weight coefficient of GGA, GGA refers to the geological condition score, GGAM refers to the maximum value of the geological condition score, RC refers to the weight coefficient of DDA, DDA refers to the strength of the support structure, DP refers to the reference value of the strength of the support structure, GGA / GGAM refers to the ratio of the geological condition score to the maximum score; The processing process of the risk assessment submodule is as follows: the comprehensive stress state value SVOP of the deep foundation pit and the strength DDA of the support structure are input into the risk assessment submodule, and the risk level assessment value ROPF is output based on the geological condition score GGA and the reference value DP of the support structure strength.

5. The deep foundation pit safety analysis method according to claim 4 is characterized in that: The calculation formula of the foundation pit safety level submodule is as follows: Security Level ; in: ROAA refers to the risk threshold value one with a value of 0.4, which means the critical value of the lower risk level. Below this value, the security risk is considered controllable; ROBB refers to the risk threshold value 2, which is 0.75; SVBB refers to the critical threshold of the comprehensive stress state, which is 0.65, indicating that when the comprehensive stress state exceeds this value, special attention should be paid to the stability of the deep foundation pit; The processing process of the foundation pit safety level submodule is as follows: the comprehensive stress state value SVOP and the risk level assessment value ROPF of the deep foundation pit are input into the foundation pit safety level submodule, and based on the risk threshold 1 ROAA, the risk threshold 2 ROBB and the comprehensive stress state critical threshold SVBB, the safety level 1, safety level 2 and safety level 3 are output.

6. The deep foundation pit safety analysis method according to claim 5, characterized in that: The safety measures module is specifically: At safety level 1, the deep foundation pit is in a low-risk state; Treatment measures: Continue to proceed according to the normal construction plan, but maintain regular monitoring and inspection of the stability of the deep foundation pit; At safety level 2, the deep foundation pit is at medium risk; Treatment measures: Take additional monitoring and preventive measures, that is, increase the number of monitoring points to improve the monitoring frequency, strengthen the inspection and maintenance of the support structure, and adjust the construction plan to reduce the impact on the stability of the deep foundation pit; At safety level 3, the deep foundation pit is at high risk; Treatment measures: Immediately stop construction activities and conduct a comprehensive safety assessment, take emergency support measures, that is, add temporary support structures or reinforce existing support structures, and organize an expert team to discuss and formulate a detailed safety treatment plan, and ensure that all construction personnel understand and comply with relevant safety regulations.

7. The deep foundation pit safety analysis method according to claim 1, characterized in that: The data acquisition module uses stress sensors, geological exploration equipment and support structure strength testing equipment; The geological exploration equipment is specifically a geological radar and a drilling equipment, which is used to analyze geological conditions to evaluate the geological condition score; The support structure strength testing equipment is specifically a pressure sensor and a tensile testing machine, which are used to measure the support structure to output the strength DDA of the support structure.

8. The deep foundation pit safety analysis method according to claim 7, characterized in that: The stress sensors are installed on the side walls and the bottom of the deep foundation pit, and the normal stress and the shear stress of the deep foundation pit in the x and y directions are measured by the stress sensors.

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