Method and system for evaluating stability of point-shaped foundation pit supporting structure

Abstract

The invention relates to the technical field of foundation pit supporting, in particular to a point-shaped foundation pit supporting structure stability evaluation method and system, and the method comprises the steps: obtaining the engineering parameters, geological data and dynamic monitoring data of a target foundation pit; performing feature extraction on the dynamic monitoring data to obtain a stability evaluation index vector; calculating spatial effect characteristic parameters of the target foundation pit based on the engineering parameters; the influence of geological data on the spatial effect is considered, the spatial effect characteristic parameters are corrected, mapping is carried out in a preset spatial effect weight database, and an evaluation index weight vector of the target foundation pit is obtained; performing weighted calculation on the stability evaluation index vector and the evaluation index weight vector to obtain a stability evaluation index of the target foundation pit, and comparing the stability evaluation index with a preset stability threshold to obtain a stability evaluation result; according to the method, the change of the space effect of the foundation pit under different geological conditions can be reflected more accurately, so that the final stability evaluation index can reflect the actual stability of the foundation pit more accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation pit support, and particularly to a method and system for evaluating the stability of a point - shaped foundation pit support structure. Background Technique

[0002] With the three - dimensional development of urban underground space development, point - shaped foundation pits, such as subway entrances and exits, utility tunnel working wells, etc., due to their "small and deep" structural characteristics, have shown an explosive growth in municipal engineering. Such foundation pits have significant spatial effect characteristics, and the forces on the support structure show obvious spatial anisotropy.

[0003] Most of the existing methods for evaluating the stability of foundation pit support structures do not fully consider the spatial effects of point - shaped well - type foundation pits. Some methods simply apply the evaluation methods for large - scale foundation pits, ignoring the influence brought by the reduction of the aspect ratio of such foundation pits, and do not effectively combine the geological conditions with the spatial effects for analysis, making it difficult to accurately evaluate the stability of the foundation pit using monitoring data. Summary of the Invention

[0004] To solve the above - mentioned technical problems, the present invention provides a method and system for evaluating the stability of a point - shaped foundation pit support structure, which can more accurately reflect the changes in the spatial effects of the foundation pit under different geological conditions, so that the finally calculated stability evaluation index can more accurately reflect the actual stability of the foundation pit.

[0005] In a first aspect, the present invention provides a method for evaluating the stability of a point - shaped foundation pit support structure, including: Obtain the engineering parameters, geological data, and dynamic monitoring data of the target foundation pit; Extract features from the dynamic monitoring data to obtain a stable evaluation index vector; Based on the engineering parameters, calculate the spatial effect characteristic parameters of the target foundation pit; Considering the influence of the geological data on the spatial effect, correct the spatial effect characteristic parameters, and map the corrected spatial effect characteristic parameters in a preset spatial effect weight database to obtain an evaluation index weight vector of the target foundation pit; Perform weighted calculation on the stable evaluation index vector and the evaluation index weight vector to obtain a stability evaluation index of the target foundation pit, and compare it with a preset stability threshold to obtain a stability evaluation result.

[0006] Furthermore, the engineering parameters include the foundation pit depth, foundation pit length, foundation pit width, undrained shear strength of soil, soil unit weight, and the distance to adjacent sensitive buildings; The geological data includes the soil layer permeability coefficient, soil layer compression modulus, and initial earth pressure; The dynamic monitoring data includes the displacement of the supporting structure, the distribution of earth pressure, the settlement of the surrounding ground surface, and the stress and strain of the supporting structure.

[0007] Furthermore, the stability evaluation index vector includes deformation indexes, stress indexes, and environmental indexes. The evaluation index weight vector includes the weight of deformation indexes, the weight of stress indexes, and the weight of environmental indexes.

[0008] Furthermore, the deformation indexes include the ratio of the maximum lateral displacement to the depth. The stress indexes include the extreme value of the bending moment of the supporting structure and the asymmetry coefficient of earth pressure. The environmental indexes include the surrounding settlement gradient and the pipeline deformation amount.

[0009] Furthermore, the calculation method of the spatial effect characteristic parameter is as follows: ; where Se represents the spatial effect characteristic parameter; H represents the depth of the foundation pit; L represents the length of the foundation pit; B represents the width of the foundation pit; C u represents the undrained shear strength of the soil; γ represents the unit weight of the soil; D represents the distance to the adjacent sensitive building. When L / B ≤ 1.5, the strong spatial effect correction factor α = 1.5 is automatically triggered, and according to S e ′ = α * S e parameter strengthening is carried out.

[0010] Furthermore, the correction of the spatial effect characteristic parameter is carried out, and the calculation formula is: ; where β represents the geological coupling coefficient; k represents the soil layer permeability coefficient; E s represents the soil layer compression modulus; P0 represents the initial earth pressure. represents the spatial effect characteristic parameter corrected by the dynamic attenuation function; t represents the exposure time of the foundation pit; T represents the soft soil rheological time constant; e represents the natural constant.

[0011] Furthermore, the calculation formula of the stability evaluation index is: ; where I represents the stability evaluation index; n represents the number of indexes in the stability evaluation index vector. represents the i-th index number in the stability evaluation index vector. represents the weight coefficient corresponding to the i-th index number in the evaluation index weight vector.

[0012] On the other hand, the present application also provides a stability evaluation system for a point-like foundation pit supporting structure, and the system includes: A data acquisition module for obtaining engineering parameters, geological data, and dynamic monitoring data of a target foundation pit; A feature extraction module for extracting features from the dynamic monitoring data to obtain a stability evaluation index vector reflecting the stability state of the foundation pit; A spatial effect calculation module: calculating spatial effect characteristic parameters of the target foundation pit based on the engineering parameters; A weight determination module for correcting the spatial effect characteristic parameters by considering the influence of the geological data on the spatial effect, and mapping the corrected spatial effect characteristic parameters in a preset spatial effect weight database to obtain an evaluation index weight vector of the target foundation pit; A stability evaluation module for performing weighted calculation on the stability evaluation index vector and the evaluation index weight vector to obtain a stability evaluation index of the target foundation pit, and comparing it with a preset stability threshold to obtain a stability evaluation result.

[0013] In a third aspect, the present application provides an electronic device, including a bus, a transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor. The transceiver, the memory, and the processor are connected through the bus. When the computer program is executed by the processor, the steps in any one of the above methods are implemented.

[0014] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps in any one of the above methods are implemented.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: By obtaining the engineering parameters, geological data, and dynamic monitoring data of the target foundation pit, information is collected from multiple dimensions, avoiding the one-sidedness of evaluation caused by relying only on a single data source; On this basis, operations such as feature extraction, calculation of spatial effect characteristic parameters, and correction of the influence of geological data are carried out, which can comprehensively consider the spatial effect, geological conditions, and real-time state of the foundation pit, making the finally calculated stability evaluation index more accurately reflect the actual stability of the foundation pit and overcoming the problem that it is difficult to accurately evaluate by existing methods; When calculating the spatial effect characteristic parameters, the influence of geological data is considered and corrected, changing the situation where the two are not effectively combined in existing methods, and being able to more accurately reflect the changes in the spatial effect of the foundation pit under different geological conditions; Processing the dynamic monitoring data and incorporating it into the evaluation process makes the evaluation no longer limited to static analysis; As various situations change during the construction and use of the foundation pit, the dynamic monitoring data can reflect these changes in real time, and thus the stability evaluation result is also updated accordingly, timely discovering potential risks. Description of the Drawings

[0016] Figure 1 is the flowchart of the stability evaluation method for the point - type foundation pit support structure of the present invention; Figure 2 is the structural block diagram of the stability evaluation system for the point - type foundation pit support structure of the present invention. Detailed implementation manners

[0017] The present application will be described below in conjunction with the accompanying drawings in the present application.

[0018] As Figure 1 shown, a stability evaluation method for a point - type foundation pit support structure of the present invention specifically includes the following steps: Step S1, obtaining engineering parameters, geological data and dynamic monitoring data of the target foundation pit; Step S2, performing feature extraction on the dynamic monitoring data to obtain a stable evaluation index vector; Step S3, calculating the spatial effect characteristic parameters of the target foundation pit based on the engineering parameters; Step S4, considering the influence of the geological data on the spatial effect, correcting the spatial effect characteristic parameters, and mapping the corrected spatial effect characteristic parameters in a preset spatial effect weight database to obtain an evaluation index weight vector of the target foundation pit; Step S5, performing weighted calculation on the stable evaluation index vector and the evaluation index weight vector to obtain a stability evaluation index of the target foundation pit, and comparing it with a preset stability threshold to obtain a stability evaluation result.

[0019] In this embodiment, through the chain of engineering parameters → spatial effect characteristic parameters → correction mapping, for the first time, the geometric characteristics of small size, deep vertical constraint, and plane shape variation of the point - type foundation pit are transformed into quantifiable evaluation parameters. Combined with geological data correction, the calculation of safety factors such as anti - overturning and anti - heave conforms to the actual working conditions; the cross - verification of dynamic monitoring data with spatial effect parameters and geological data forms a three - dimensional evaluation dimension of static geometric characteristics + dynamic force response + geological risk factors; the traditional method equivalentizes the point - type foundation pit to a plane strain problem, while the present method realizes accurate modeling of the anisotropic stress of the point - type foundation pit through a spatial effect weight database, avoiding cost waste caused by conservative design of small foundation pits by the specification formula; establishing a coupling mechanism of geological parameters → spatial effect correction → dynamic weight distribution, binding the seepage risk assessment to the geometric form of the foundation pit, and solving the disconnection problem of independent calculation of geological parameters and geometric parameters in the traditional method; The combination of spatial effect characteristic parameters and geological correction is not a simple superposition of parameters, but through the modified parameter → weight mapping mechanism, the influence of geological conditions on foundation pit stability is transformed from background parameters to active adjustment factors; for example, the correction of the length-to-depth ratio by the thickness of the soft soil layer not only changes the value of a single indicator, but also redistributes the importance of each stability indicator through the weight database; dynamic monitoring data is not only used for real-time evaluation, but also reversely optimizes the preset database through feature extraction → weight mapping; for example, when the measured failure cases of a certain type of foundation pit accumulate to a certain number, the system automatically adjusts the weight distribution under this condition to form a self-evolving system of evaluation → practice → optimization; safety redundancy is reduced through spatial effect correction, and risk omission is avoided through dynamic monitoring, so that the support design can find the optimal balance between safety factor and engineering cost; achieving the dual goals of maintaining safety and reducing cost is a fundamental breakthrough in the conflicting relationship between safety and economy caused by the one-size-fits-all evaluation of traditional methods.

[0020] As a preferred embodiment of the present invention, step S1 aims to comprehensively collect various data related to the target foundation pit for subsequent foundation pit support structure stability assessment, wherein the engineering parameters include: Pit size parameters: Obtain the pit depth, length and width. The size information directly determines the spatial form of the pit. The pit depth affects the size and distribution of the earth pressure borne by the supporting structure. The length and width of the pit, especially the length-to-width ratio, are important parameters for analyzing the characteristic parameters of the spatial effect. Soil mechanical parameters: Undrained shear strength and soil mass reflect the mechanical properties of the soil itself; Undrained shear strength determines the soil's ability to resist shear failure; Soil mass affects the calculation of earth pressure, which in turn affects the force analysis of the support structure; Surrounding environment parameters: The distance to adjacent sensitive buildings is a key parameter for considering the impact of foundation pit construction on the surrounding environment. If the foundation pit is too close to sensitive buildings, soil deformation and support structure displacement during construction may pose a threat to the safety of the building.

[0021] The geological data include: Soil permeability coefficient: reflects the permeability of groundwater in the soil. The permeability coefficient affects the flow of groundwater during the excavation of the foundation pit, and thus affects the stability of the soil. If the permeability coefficient is large, it may cause changes in the pore water pressure in the soil around the foundation pit, causing permeability deformation of the soil, which will have an adverse effect on the foundation pit support structure. Soil compression modulus: used to measure the compressibility of soil under pressure; the smaller the soil compression modulus, the easier it is for the soil to be compressed and deformed when subjected to external forces, resulting in surface settlement around the foundation pit and deformation of the support structure; Initial earth pressure: The initial earth pressure is the pressure borne by the soil mass in its natural state, which helps to accurately analyze the magnitude and distribution law of the earth pressure borne by the retaining structure.

[0022] The dynamic monitoring data includes: Displacement data of the retaining structure: By monitoring the displacement of the retaining structure, such as lateral displacement; the ratio of the maximum lateral displacement to the depth is an important part of the deformation index, which can reflect the severity of the deformation of the retaining structure and its variation law with depth; Earth pressure distribution data: The earth pressure distribution data records the magnitude and distribution of the pressure exerted by the soil mass around the foundation pit on the retaining structure; the earth pressure asymmetry coefficient, as a stress index, can measure the uneven stress degree of the foundation pit retaining structure by analyzing the symmetry of the earth pressure distribution; Peripheral ground settlement data: The peripheral ground settlement reflects the degree of disturbance of the surrounding soil mass caused by the excavation of the foundation pit; the peripheral settlement gradient, as an environmental index, can reflect the spatial variation of the ground settlement and is used to evaluate the influence range and degree of the foundation pit construction on the surrounding environment; Stress and strain data of the retaining structure: It is used to reflect the internal stress state of the retaining structure. By monitoring the stress and strain conditions, potential failure risks that may occur in the retaining structure can be detected in a timely manner.

[0023] As a preferred embodiment of the present invention, the stability of a point-shaped foundation pit is affected by various factors, and a single index cannot comprehensively and accurately evaluate its stability; the stability evaluation indexes are divided into deformation indexes, stress indexes and environmental indexes, which can reflect the state of the foundation pit from different angles and can more comprehensively and meticulously evaluate the stability of the foundation pit retaining structure; the dynamic monitoring data is a direct reflection of the real-time state of the foundation pit, but the original monitoring data is relatively complex and cannot be directly used to evaluate the stability of the foundation pit; through feature extraction, key information closely related to the stability of the foundation pit can be extracted from a large amount of monitoring data, and a stability evaluation index vector can be constructed, so as to convert the complex monitoring data into parameters that can be used for quantitative evaluation; Specifically, for the deformation index, among the displacement data of the retaining structure, the ratio of the maximum lateral displacement to the depth is mainly concerned; by arranging displacement monitoring sensors, such as inclinometers, at different depth positions of the retaining structure, the lateral displacement data at each depth can be continuously obtained; within a certain period of time, the maximum value of the lateral displacement is found and divided by the corresponding depth to obtain the ratio of the maximum lateral displacement to the depth; for example, if at a certain moment, the maximum lateral displacement of 50 mm is monitored at a depth of 10 m of the foundation pit retaining structure, then the ratio is 50÷10000 = 0.005; this ratio can intuitively reflect the difference in the deformation degree of the retaining structure at different depths, and the larger the ratio, the more significant the deformation of the retaining structure at this depth; For the earth pressure distribution data in the force-related indicators, by analyzing the data collected by earth pressure sensors at different positions, the earth pressure asymmetry coefficient is calculated; first, determine the distribution of the earth pressure around the foundation pit, find the areas with relatively large and small pressures, and then calculate this coefficient according to a specific calculation formula (such as asymmetry coefficient = (maximum earth pressure - minimum earth pressure) ÷ average earth pressure); for the extreme value of the bending moment of the supporting structure, stress and strain sensors are arranged at the key force-bearing parts inside the supporting structure (such as support nodes, pile bodies, etc.). These sensors will monitor the stress changes of the structure in real time, and according to the relationship between stress and bending moment, calculate the bending moment values at different times, and find the extreme value of the bending moment from them; for example, by processing the sensor data on a certain support beam, the extreme value of the bending moment during the excavation of the foundation pit is obtained as 100 kN·m. For the environmental indicators, in the processing of the surrounding ground settlement data, the surrounding settlement gradient is calculated; a number of settlement monitoring points are arranged around the foundation pit at a certain interval, and a level is used to regularly measure the settlement of each point; according to the settlement and the distance between the monitoring points, calculate the ratio of the settlement difference between adjacent monitoring points to the distance to obtain multiple settlement gradient values; for example, the distance between two adjacent monitoring points is 5 meters, the settlement of one point is 20 millimeters, and the settlement of the other point is 10 millimeters, then the settlement gradient of this section is (20 - 10) ÷ 5000 = 0.002; for the pipeline deformation amount, a displacement monitoring device (such as an electronic displacement meter) is installed on the pipeline adjacent to the foundation pit, and the deformation data of the pipeline in each direction is directly read to obtain the pipeline deformation amount. In this embodiment, the deformation-related indicators intuitively reflect the deformation degree and trend of the supporting structure. The ratio in the depth direction can reflect the relative magnitude of the deformation at different depths, providing a basis for judging whether the deformation is within a reasonable range; the force-related indicators start from the perspective of the structure's force. The extreme value of the bending moment reflects the maximum internal force borne by the supporting structure, and the earth pressure asymmetry coefficient reflects the non-uniformity of the earth pressure distribution, helping to understand the complexity of the supporting structure's force; the environmental indicators can effectively evaluate the impact degree of the foundation pit construction on the surrounding environment; the surrounding settlement gradient can reflect the spatial change trend of the ground settlement caused by the excavation of the foundation pit and determine the influence range; the pipeline deformation amount is directly related to the safety of the surrounding underground pipelines, discovering the risk of excessive pipeline deformation in advance, avoiding secondary disasters caused by problems such as pipeline rupture, and ensuring the normal operation of the surrounding infrastructure.

[0024] As a preferred embodiment of the present invention, due to the significant spatial effect of the dot-shaped foundation pit, this characteristic is often ignored in traditional foundation pit assessment methods. The spatial effect characteristic parameters can integrate factors such as the depth, size, soil mechanical properties, and surrounding environment of the foundation pit, quantitatively describe the spatial effect of the dot-shaped foundation pit, provide key parameters for the subsequent stability assessment considering the spatial effect, solve the problem of insufficient consideration of the spatial effect in existing methods, and make the assessment more in line with the actual working conditions of the dot-shaped foundation pit. In step S3, according to the engineering parameters, calculate the spatial effect characteristic parameters of the target foundation pit, and the calculation formula is: ; where Se represents the spatial effect characteristic parameter; H represents the depth of the foundation pit, which directly affects the magnitude and distribution of the earth pressure on the retaining structure. The greater the depth, the greater the earth pressure usually is; L represents the length of the foundation pit, and B represents the width of the foundation pit. The two determine the plane shape of the foundation pit, and the ratio L / B reflects the aspect ratio relationship of the foundation pit, which has an important impact on the spatial effect; C u represents the undrained shear strength of the soil, which reflects the ability of the soil to resist shear failure. The higher the strength, the relatively better the stability of the soil; γ represents the unit weight of the soil, which affects the calculation of the earth pressure; D represents the distance to the adjacent sensitive building, which is related to the impact of the foundation pit construction on the surrounding environment. The closer the distance, the greater the possible impact; When L / B ≤ 1.5, it means that the aspect ratio of the foundation pit is small and the spatial effect is more significant. At this time, the strong spatial effect correction factor α = 1.5 is automatically triggered, and according to S e ′ = α * S e to strengthen the spatial effect characteristic parameter.

[0025] In this embodiment, the above calculation method of the spatial effect characteristic parameter integrates multiple key factors such as the depth, size, soil properties, and surrounding environment of the foundation pit, comprehensively reflects the comprehensive impact of the above factors on the spatial effect, avoids the problem of incomplete consideration of a single factor, and makes the quantification of the spatial effect more scientific and accurate; by setting the strong spatial effect correction factor, when the aspect ratio of the foundation pit meets specific conditions, the spatial effect characteristic parameter is strengthened, which can more prominently reflect the significant spatial effect of such foundation pits, make the assessment more in line with the actual situation, provide a more accurate parameter basis for the subsequent stability assessment, effectively avoid the assessment deviation caused by insufficient consideration of the spatial effect, and improve the reliability and practicality of the assessment results.

[0026] As a preferred embodiment of the present invention, different stability assessment indicators have different degrees of influence on the stability of the foundation pit. Assigning corresponding weights to them can more accurately reflect the relative importance of each indicator in the stability assessment and make the final stability assessment result more in line with the actual situation; therefore, the assessment indicator weight vector includes the weight of the deformation type indicator, the weight of the force type indicator, and the weight of the environmental type indicator; Specifically, considering the influence of geological data on spatial effects, the characteristic parameters of spatial effects are corrected; according to the corrected characteristic parameters of spatial effects, mapping is performed in a preset spatial effect weight database to obtain the weights of deformation type indicators, force type indicators, and environmental type indicators; for example, if a foundation pit is in soft soil geology and the soil layer compression modulus is small, it may increase the weight of deformation type indicators; if there are important pipelines around the foundation pit, the weight of environmental type indicators will increase accordingly; in actual operation, the corrected characteristic parameters of spatial effects are input into the database, and through preset algorithms and rules, the corresponding weight values are output. Through weight allocation, the role of key indicators in the evaluation is highlighted, avoiding evaluation biases caused by the same weights for each indicator; for different geological conditions, surrounding environments, and foundation pit types, the weights can be adjusted according to the actual situation, improving the pertinence and accuracy of the evaluation; moreover, when the weight vector is combined with the stable evaluation indicator vector, the stability status of the foundation pit can be more realistically reflected when calculating the stability evaluation index through weighted calculation.

[0027] More specifically, the formula for correcting the characteristic parameters of spatial effects is: ; where β represents the geological coupling coefficient, reflecting the degree of influence of geological conditions on spatial effects; k represents the soil layer permeability coefficient, reflecting the permeability performance of groundwater in the soil. The larger the permeability coefficient, the easier the groundwater flows, and the greater the impact on soil stability; E s represents the soil layer compression modulus, measuring the compressibility of the soil under pressure. The smaller the compression modulus, the easier the soil is to compress and deform; P0 represents the initial soil pressure, which is the pressure borne by the soil in its natural state. represents the characteristic parameters of spatial effects corrected using the dynamic attenuation function; t represents the exposure time of the foundation pit. The longer the exposure time of the foundation pit, the greater the influence of the soil by the outside world, and the lower the stability may be; T represents the soft soil rheological time constant, reflecting the characteristics of soft soil deformation over time; e represents the natural constant.

[0028] In this embodiment, the calculation of the previous spatial effect characteristic parameters only considered the engineering parameters of the foundation pit. However, geological conditions have an important impact on the spatial effect of the foundation pit. For example, soil layer permeability coefficient, compression modulus, etc. will change the mechanical properties of the soil mass and the groundwater flow conditions, and thus affect the stability of the foundation pit. By calculating the geological coupling coefficient, geological parameters such as soil layer permeability coefficient, compression modulus, shear strength of the soil mass, and initial earth pressure are comprehensively considered, which comprehensively reflects the influence of geological conditions on the spatial effect, enables the spatial effect characteristic parameters to more accurately reflect the spatial effect of the foundation pit under the actual geological conditions, and provides more reliable parameters for subsequent stability assessment. The exposure time of the foundation pit and the rheological time constant of soft soil are introduced into the dynamic attenuation function, considering the changes in the soil mass characteristics at different time stages of the foundation pit, which is more in line with the actual situation of the dynamic change of the foundation pit stability over time in actual engineering, and further improves the accuracy and timeliness of the assessment. The corrected spatial effect characteristic parameters are used as the basis for mapping in the preset spatial effect weight database, which can more reasonably allocate the weights of deformation type, stress type, and environment type indicators, making the weight allocation more in line with the actual working conditions. Furthermore, when calculating the stability assessment index by weighted calculation, it can more truly reflect the stability status of the foundation pit.

[0029] As a preferred embodiment of the present invention, for different foundation pits, due to the differences in their engineering parameters, geological conditions, surrounding environments, etc., the influence degrees of each stability assessment index (deformation type, stress type, environment type) on their stability are also different. If a unified weight is used to evaluate all foundation pits, it will lead to inaccurate assessment results and unable to truly reflect the actual stability situation of the foundation pit. By mapping the corrected spatial effect characteristic parameters with the preset spatial effect weight database, appropriate weights can be assigned to each assessment index according to the specific characteristics of each foundation pit, making the assessment results more in line with the actual situation and improving the pertinence and accuracy of the assessment. In the early stage of engineering practice, collect a large amount of foundation pit data under different types, different geological conditions, different surrounding environments, etc., including their engineering parameters, geological data, spatial effect characteristic parameters, and actual stability status, etc. Combine means such as expert experience, theoretical analysis, and numerical simulation, and preset the corresponding deformation type index weights, stress type index weights, and environment type index weights for different ranges of spatial effect characteristic parameters to construct a preset spatial effect weight database. For example, for a foundation pit in soft soil with a small aspect ratio, according to past experience and analysis, determine that its deformation type index weight is relatively high, and record the corresponding parameter range and weight value in the database. After obtaining the corrected spatial effect characteristic parameters of the target foundation pit, input the parameter values into the preset spatial effect weight database; the database automatically retrieves the weight range matching the parameter values through the preset algorithms and rules inside; for example, if the corrected spatial effect characteristic parameters indicate that the spatial effect of the foundation pit is significant and under specific geological conditions, the database will find the corresponding weights of deformation index, stress index and environmental index according to the preset rules, output these weight values, so as to obtain the evaluation index weight vector of the target foundation pit.

[0030] In this embodiment, the weights are determined according to the unique spatial effect characteristic parameters of each foundation pit, fully considering the individual differences of the foundation pits, enabling each evaluation index to play an appropriate role in the stability evaluation, avoiding a one-size-fits-all weight setting, being able to more accurately reflect the true stability of the foundation pits, and providing a reliable basis for engineering decisions; it can adapt to various types of foundation pits. Whether the foundation pit has complex geological conditions, special surrounding environments or unique geometric shapes, it can find appropriate weights through mapping in the database, making the evaluation method have wide applicability and being able to better serve diverse municipal engineering point foundation pit projects; with the continuous accumulation of engineering practice and the supplement of new data, the preset spatial effect weight database can be continuously updated and improved, which helps to continuously optimize the distribution of evaluation index weights and improve the quality and level of foundation pit stability evaluation.

[0031] As a preferred embodiment of the present invention, the stability evaluation index vector covers deformation index, stress index and environmental index. The above indexes reflect the stability state of the foundation pit from different dimensions, but the influence degrees of each index on the overall stability are different; the evaluation index weight vector assigns reasonable weights to the deformation, stress and environmental indexes respectively through the previous steps in combination with geological conditions, spatial effect characteristics, etc., reflecting the importance differences of each index under different working conditions; through weighted calculation, the multi-dimensional indexes and weights are fused to form a comprehensive stability evaluation index. Specifically, let the stability evaluation index vector be X = [x1, x2,..., x n , where x1, x2, etc. respectively represent the specific index values of deformation index (such as the ratio of the maximum lateral displacement to the depth), stress index (such as the extreme value of the support structure moment, the earth pressure asymmetry coefficient), environmental index (such as the surrounding settlement gradient, the pipeline deformation amount), etc.; the evaluation index weight vector is W = [w1, w2,..., w n , and w1, w2, etc. are the weights corresponding to the indexes respectively; calculate according to the weighted calculation formula, and the formula is as follows: ; where I represents the stability evaluation index. The preset stability threshold is a standard value determined based on engineering experience, specification requirements, and a large number of simulations and actual case analyses, used to measure whether the foundation pit is in a stable state; compare the calculated stability evaluation index with the preset stability threshold; if the stability evaluation index does not exceed the preset stability threshold, it is determined that the target foundation pit is in a stable state; if it exceeds, it is determined that the target foundation pit is in an unstable state, and the reasons need to be further analyzed and corresponding measures need to be taken, such as strengthening the support structure, adjusting the construction plan, etc.

[0032] In this embodiment, multiple indexes affecting the stability of the foundation pit are integrated into specific values through weighted calculation to achieve a quantitative evaluation of the stability of the foundation pit. Compared with analyzing each index separately, it is more intuitive and clear, facilitating engineering personnel to quickly understand and judge the stability status of the foundation pit; the comparison process with the preset stability threshold can quickly obtain the evaluation result, providing a direct basis for engineering decision-making; whether to continue construction, adjust construction parameters, or take reinforcement measures, decisions can be quickly made based on the clear evaluation result, improving the efficiency of engineering construction and avoiding construction period delays or resource waste caused by untimely or unclear evaluations; accurate stability evaluation results can timely detect potential unstable factors in the foundation pit. For foundation pits determined to be unstable, measures can be taken in a timely manner to effectively prevent the occurrence of safety accidents such as foundation pit collapse and surrounding environment damage, ensuring the safety of engineering construction and the surrounding environment.

[0033] As Figure 2 shown, a stability evaluation system for a point-shaped foundation pit support structure of the present invention specifically includes the following modules: A data acquisition module, used to obtain the engineering parameters, geological data, and dynamic monitoring data of the target foundation pit; A feature extraction module, used to extract features from the dynamic monitoring data to obtain a stable evaluation index vector reflecting the stability state of the foundation pit; A spatial effect calculation module: based on the engineering parameters, calculate the spatial effect characteristic parameters of the target foundation pit; A weight determination module, used to consider the influence of the geological data on the spatial effect, correct the spatial effect characteristic parameters, and map the corrected spatial effect characteristic parameters in a preset spatial effect weight database to obtain an evaluation index weight vector of the target foundation pit; A stability evaluation module, used to perform weighted calculation on the stable evaluation index vector and the evaluation index weight vector to obtain a stability evaluation index of the target foundation pit, and compare it with the preset stability threshold to obtain a stability evaluation result.

[0034] In this embodiment, the system comprehensively obtains engineering parameters, geological data, and dynamic monitoring data through the data acquisition module, breaking the limitation of traditional evaluation methods that only rely on a single type of data; the data from different sources complement each other, enabling the evaluation results to more truly reflect the actual state of the foundation pit; the spatial effect calculation module specifically calculates the spatial effect characteristic parameters of the target foundation pit based on engineering parameters, fully considering the small and deep structural characteristics of the point-shaped well foundation pit and the influence brought by the reduction of the aspect ratio, in sharp contrast to the traditional method of simply applying the evaluation method for large foundation pits, making the evaluation results more in line with the actual situation of the point-shaped foundation pit; the weight determination module innovatively considers the influence of geological data on the spatial effect and corrects the spatial effect characteristic parameters; by establishing a quantitative relationship between the geological conditions and the spatial effect, the system can more accurately reflect the role of geological factors in the stability of the foundation pit and solve the problem that existing methods ignore geological conditions; the system extracts features from the dynamic monitoring data through the feature extraction module to obtain a stable evaluation index vector, enabling the evaluation process to reflect the stability state of the foundation pit in real time and promptly capture the deformation and stress changes of the foundation pit; the system considers the influence of multiple factors through the comprehensive evaluation method, avoiding the one-sidedness of single-factor evaluation and making the evaluation results more comprehensive and accurate; by comparing the stability evaluation index with a preset stability threshold, a stability evaluation result is obtained, facilitating engineering personnel to quickly judge the stability state of the foundation pit and take corresponding measures according to the evaluation results.

[0035] In addition, the present application also provides an electronic device, including a bus, a transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor. The transceiver, the memory, and the processor are respectively connected through the bus. When the computer program is executed by the processor, it realizes each process of the method embodiment for controlling the output data and can achieve the same technical effect. To avoid repetition, it will not be elaborated here.

[0036] The above is only a preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for evaluating the stability of a dot-shaped foundation pit support structure, characterized in that, The method includes: Obtaining the engineering parameters, geological data, and dynamic monitoring data of the target foundation pit; Performing feature extraction on the dynamic monitoring data to obtain a stable evaluation index vector; Calculating the spatial effect characteristic parameters of the target foundation pit based on the engineering parameters; Considering the influence of the geological data on the spatial effect, correcting the spatial effect characteristic parameters, and mapping the corrected spatial effect characteristic parameters in a preset spatial effect weight database to obtain the evaluation index weight vector of the target foundation pit; Performing weighted calculation on the stable evaluation index vector and the evaluation index weight vector to obtain the stability evaluation index of the target foundation pit, and comparing it with a preset stability threshold to obtain the stability evaluation result.

2. The method for evaluating the stability of the dot-shaped foundation pit support structure according to claim 1, wherein, The engineering parameters include the foundation pit depth, foundation pit length, foundation pit width, undrained shear strength of the soil, soil unit weight, and the distance to adjacent sensitive buildings; The geological data includes the soil layer permeability coefficient, soil layer compression modulus, and initial earth pressure; The dynamic monitoring data includes the displacement of the support structure, earth pressure distribution, surrounding ground settlement, and stress and strain of the support structure.

3. The method for evaluating the stability of the dot-shaped foundation pit support structure according to claim 2, characterized in that, The stable evaluation index vector includes deformation type indexes, stress type indexes, and environmental type indexes; The evaluation index weight vector includes deformation type index weights, stress type index weights, and environmental type index weights.

4. The method for evaluating the stability of the dot-shaped foundation pit support structure according to claim 3, characterized in that, The deformation type indexes include the ratio of the maximum lateral displacement to the depth; The stress type indexes include the extreme value of the bending moment of the support structure and the earth pressure asymmetry coefficient; The environmental type indexes include the surrounding settlement gradient and the pipeline deformation amount.

5. The method for evaluating the stability of the dot-shaped foundation pit support structure according to claim 4, wherein The calculation method of the spatial effect characteristic parameters is as follows: ; Among them, Se represents the spatial effect characteristic parameter; H represents the foundation pit depth; L represents the foundation pit length; B represents the foundation pit width; C u represents the undrained shear strength of the soil; γ represents the unit weight of the soil; D represents the distance to the adjacent sensitive building; When L / B ≤ 1.5, the strong space effect correction factor α = 1.5 is automatically triggered, and the parameter enhancement is carried out according to S e ′ = α * S e for parameter enhancement.

6. The method for evaluating the stability of the dot-shaped foundation pit support structure according to claim 5, characterized in that, The correction of the spatial effect characteristic parameter is calculated by the following formula: ; Among them, β represents the geological coupling coefficient; k represents the soil layer permeability coefficient; E s represents the soil layer compression modulus; P0 represents the initial soil pressure; represents the spatial effect characteristic parameter corrected by the dynamic attenuation function; t represents the foundation pit exposure time; T represents the soft soil rheological time constant; e represents the natural constant.

7. The method for evaluating the stability of the dot-shaped foundation pit support structure according to claim 6, characterized in that, The calculation formula of the stability evaluation index is as follows: ; Wherein, I represents the stability evaluation index; n represents the number of indicators in the stable evaluation index vector; represents the i-th index quantity in the stable evaluation index vector; represents the weight coefficient corresponding to the i-th index quantity in the evaluation index weight vector.

8. A stability evaluation system for a point-like foundation pit support structure, characterized in that, The system includes: A data acquisition module for obtaining the engineering parameters, geological data, and dynamic monitoring data of the target foundation pit; A feature extraction module for performing feature extraction on the dynamic monitoring data to obtain a stable evaluation index vector reflecting the stability state of the foundation pit; A spatial effect calculation module: calculating the spatial effect characteristic parameters of the target foundation pit based on the engineering parameters; A weight determination module for considering the influence of the geological data on the spatial effect, correcting the spatial effect characteristic parameters, and mapping the corrected spatial effect characteristic parameters in a preset spatial effect weight database to obtain the evaluation index weight vector of the target foundation pit; A stability evaluation module for performing weighted calculation on the stable evaluation index vector and the evaluation index weight vector to obtain the stability evaluation index of the target foundation pit, and comparing it with a preset stability threshold to obtain the stability evaluation result.

9. An electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected through the bus, and is characterized in that, When the computer program is executed by the processor, it implements the steps in the method according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps in the method according to any one of claims 1-7.

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