Optimization design method for foundation pit self-stabilization type supporting system

Abstract

The invention provides an optimization design method for a self-stabilization type supporting system of a foundation pit, and relates to the technical field of foundation pit engineering construction, and the optimization design method specifically comprises the steps that an inclined forward supporting pile is adopted to replace a traditional reinforced concrete horizontal support so as to provide resistance and balance the pressure of soil outside the pit; mechanical parameters and environmental parameters of the foundation pit are collected; carrying out dimensionless processing on the parameters to generate a stress index, a deformation rate and vibration intensity; and calculating a foundation pit stability coefficient according to the generated indexes, comparing the foundation pit stability coefficient with a preset safety threshold value, and when an unsafe state is detected, triggering a feedback mechanism to adjust parameters of the supporting structure in real time. The inclined forward supporting piles are adopted to replace traditional reinforced concrete horizontal supports, resistance is provided through the inclined forward supporting piles, and therefore the stability of the foundation pit supporting structure is optimized, the construction period is shortened, and the construction cost is reduced; meanwhile, the invention provides a foundation pit stability coefficient calculation method based on multiple parameters, and the foundation pit stability state can be monitored in real time.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit engineering construction, and in particular to an optimization design method for a foundation pit self-stabilizing support system. Background Art

[0002] In building construction, foundation pit support structures are important infrastructure to ensure the smooth progress of underground projects. The traditional foundation pit support method mainly uses reinforced concrete horizontal support, which can provide sufficient support force under relatively simple geological conditions to ensure the stability of the soil around the foundation pit. However, the construction period of reinforced concrete horizontal support structures is long and requires a large amount of materials and human resources, resulting in high construction costs. In addition, when the foundation pit construction environment is complex, such as high groundwater levels or unstable geological conditions, reinforced concrete horizontal support structures often find it difficult to effectively cope with these challenges. In the case of severe groundwater infiltration, traditional support structures are susceptible to corrosion, further affecting their support effect and service life.

[0003] Existing foundation pit support technology also has certain deficiencies in monitoring and feedback mechanisms. Traditional monitoring systems mainly rely on a single parameter, such as soil pressure or foundation pit deformation, and lack comprehensive consideration of multiple parameters. This single-parameter monitoring method is difficult to fully reflect the actual stability of the foundation pit, especially when environmental factors are variable, such as humidity changes, groundwater level fluctuations, and construction vibrations. In addition, traditional monitoring systems are mostly offline monitoring, and real-time data collection and processing cannot be achieved, resulting in the inability to make effective adjustment measures in time when abnormalities occur in the foundation pit support structure. This lagging adjustment mechanism increases the risk of foundation pit instability and may bring greater safety hazards and economic losses. Therefore, the existing technology urgently needs an innovative method that can monitor multiple parameters in real time during the construction process, accurately evaluate the stability of the foundation pit, and adjust the support structure parameters in time to improve the safety and reliability of foundation pit support.

[0004] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0005] The purpose of the present invention is to provide a method for optimizing the design of a self-stabilizing support system for a foundation pit, so as to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for optimizing the design of a self-stabilizing support system for a foundation pit, the specific steps of which include:

[0008] Step 1: Adopt self-stabilizing foundation pit support structure technology, use inclined forward support piles instead of reinforced concrete horizontal support, use inclined forward support piles to provide resistance, and achieve balance with the soil pressure outside the pit;

[0009] Step 2: Collect the mechanical parameters and environmental parameters of the foundation pit, the mechanical parameters are soil pressure, foundation pit deformation, soil shear strength and vibration acceleration, and the environmental parameters are groundwater level and environmental humidity;

[0010] Step 3: Generate a comprehensive environmental index based on the dimensionless soil pressure, soil shear strength, groundwater level and environmental humidity data; generate a deformation rate based on the dimensionless foundation pit deformation data; and generate a vibration intensity based on the dimensionless vibration acceleration data;

[0011] Step 4: Generate the foundation pit stability coefficient based on the comprehensive environmental index, deformation rate and vibration intensity, and compare it with the preset safety threshold. When an unsafe state is detected, the feedback mechanism is triggered to adjust the parameters of the supporting structure in real time.

[0012] Furthermore, the self-stabilizing foundation pit support structure technology adopted is specifically an emerging support technology which adopts inclined front support piles and rear pull rods to replace horizontal internal supports, and is combined with retaining piles, reinforcement bodies, ring beams and reinforced cushion layers. The self-stabilizing foundation pit support technology utilizes the resistance provided by the inclined front support to connect with the retaining piles to form a self-stabilizing structure, thereby controlling the horizontal displacement of the retaining piles. When the retaining has a tendency to rotate, the self-stabilizing structure is compressed by the front support, and the retaining piles are pulled out to jointly generate rotational resistance. At the same time, the inclined front support can resist the horizontal deformation of the retaining while also counter-pressing the pit bottom soil.

[0013] Furthermore, the specific logic of collecting soil pressure data is as follows: using a formation pressure sensor to record the soil pressure at the bottom of the foundation pit in real time, and recording the soil pressure value as P t ;

[0014] The specific logic of collecting the foundation pit deformation data is as follows: displacement meters are set at characteristic points around the foundation pit to monitor the foundation pit deformation data in real time, which is recorded as Δh;

[0015] The specific logic of collecting soil shear strength data is as follows: a certain volume of undisturbed soil sample is collected from the foundation pit site, prepared into a standard specimen, the specimen is placed in a uniaxial compression testing machine, axial load is gradually applied, stress and strain are measured, and a stress-strain curve is drawn. The elastic modulus E of the soil is obtained from the linear part of the stress-strain curve, i.e., the initial slope. p ;

[0016] A certain volume of undisturbed soil sample is collected from the site and prepared into a standard specimen. The specimen is placed in a uniaxial compression testing machine. During the compression process, the axial deformation and lateral deformation are measured, and the Poisson's ratio of the soil is calculated according to the following formula:

[0017]

[0018] Where v is the Poisson's ratio of the soil, ε l is the transverse strain, ε a is the axial strain;

[0019] Axial strain ε a It is the ratio of the deformation along the load direction to the original length, and the calculation formula is:

[0020]

[0021] Among them, ε a is the axial strain, ΔL is the axial deformation, that is, the length after deformation minus the original length; L0 is the original length; the transverse strain is the ratio of the deformation perpendicular to the load direction to the original length, and the calculation formula is:

[0022]

[0023] Among them, ε l is the lateral strain, ΔD is the lateral deformation, that is, the length after deformation minus the original length; D0 is the original length; the shear modulus G of the soil is calculated using the following formula:

[0024]

[0025] Among them, G is the shear strength of soil, E p is the elastic modulus of the soil, v is the Poisson’s ratio of the soil;

[0026] The specific logic of collecting vibration acceleration data is as follows: fix the accelerometer on the self-stabilizing foundation pit support structure, and measure the acceleration in the three directions of x-axis, y-axis and z-axis respectively, which are recorded as A x , A y , A z ;

[0027] The specific logic of collecting groundwater level data is as follows: monitoring wells are set up around the foundation pit, well pipes are installed to enter the groundwater layer, a water level meter is placed vertically into the well and slowly lowered until it touches the water surface, and the measured depth is recorded, that is, the vertical distance from the wellhead to the water surface, recorded as H. total ; Record the absolute height of the wellhead, that is, the absolute height of the bottom of the foundation pit, denoted as H lg ;

[0028] Calculate the groundwater level using the following formula:

[0029] H w =H lg -H total

[0030] Among them, H w is the groundwater level, H lg is the absolute height of the wellhead, H total The depth measured from the wellhead to the water surface;

[0031] A hygrometer is used to collect real-time humidity data around the foundation pit, denoted as S. The collected humidity is compared with the preset humidity assessment threshold. If it exceeds the threshold range, the difference between the current humidity and the preset threshold is calculated, denoted as ΔS; if it does not exceed the threshold range, it will not be included in the subsequent calculation of the comprehensive environmental index.

[0032] Furthermore, the formula for generating the comprehensive environmental index is as follows:

[0033]

[0034] Among them, Str is the comprehensive environmental index, G is the shear strength of soil, P is t is the soil pressure value, H w is the groundwater level, ΔS is the difference between the humidity and the preset threshold, and C1 is the first constant correction index;

[0035] The deformation rate refers to the vertical deformation rate of the foundation pit and its surrounding soil within a specific time interval. The formula for generating the deformation rate is:

[0036]

[0037] Among them, Def is the deformation rate, Δh(t) is the deformation at the current moment, Δh(t-1) is the deformation at the previous moment, and Δt is the time interval;

[0038] The generated vibration intensity is based on the formula:

[0039]

[0040] Where Vib is the vibration intensity, A x , A y , A z are the components of acceleration on the x-axis, y-axis, and z-axis respectively.

[0041] Furthermore, the formula for generating the foundation pit stability coefficient is as follows:

[0042]

[0043] Among them, FS is the foundation pit stability coefficient, Str is the comprehensive environment index, α is its preset proportional coefficient, Def is the deformation rate, β is its preset proportional coefficient, Vib is the vibration intensity, γ is its preset proportional coefficient, and α > β > γ > 0, C2 is the second constant correction index.

[0044] Furthermore, the process of generating the foundation pit stability coefficient based on the stress index, deformation rate, and vibration intensity and comparing it with the preset safety threshold is specifically as follows:

[0045] When FS ≥ FY, it indicates that the foundation pit stability coefficient is within the preset safety threshold range, that is, the foundation pit is in a safe state, and the monitoring of the foundation pit continues to be maintained;

[0046] When FS < FY, it indicates that the foundation pit stability coefficient is less than the preset safety threshold, that is, the foundation pit is in an unsafe state. Immediately organize engineers to conduct an on-site assessment of the foundation pit, confirm the reasons for the unsafe state, and take corresponding measures;

[0047] Among them, FS is the foundation pit stability coefficient, and FY is the preset safety threshold.

[0048] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0049] The present invention optimizes the stability of the foundation pit support structure and reduces the construction period and cost by using inclined forward bracing piles to replace traditional reinforced concrete horizontal supports and utilizing the inclined forward bracing piles to provide resistance. At the same time, by collecting mechanical parameters and environmental parameters and performing dimensionless processing on them, key indicators such as stress index, deformation rate, and vibration intensity are comprehensively generated. The present invention proposes a calculation method for the foundation pit stability coefficient based on multiple parameters, which can monitor the stable state of the foundation pit in real time and trigger a feedback mechanism when an unsafe state is detected for dynamic adjustment. This multi-parameter comprehensive monitoring and adjustment method improves the safety and reliability of the foundation pit support, especially showing significant advantages under complex geological conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a schematic diagram of the overall method flow of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0051] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments.

[0052] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0053] Example:

[0054] See also Figure 1 , the present invention provides a technical solution:

[0055] A method for optimizing the design of a self-stabilizing support system for a foundation pit, the specific steps of which include:

[0056] Step 1: Adopt self-stabilizing foundation pit support structure technology, use inclined forward support piles instead of reinforced concrete horizontal support, use inclined forward support piles to provide resistance, and achieve balance with the soil pressure outside the pit;

[0057] In this embodiment, the self-stabilizing foundation pit support structure technology adopted is specifically an emerging support technology that adopts inclined front support piles and rear pull rods to replace horizontal internal supports, and is combined with retaining piles, reinforcement bodies, ring beams and reinforced cushion layers. The self-stabilizing foundation pit support technology utilizes the resistance provided by the inclined front support to connect with the retaining piles to form a self-stabilizing structure to control the horizontal displacement of the retaining piles. When the retaining has a tendency to rotate, the self-stabilizing structure is compressed by the front support, and the retaining piles are pulled out to jointly generate rotational resistance. At the same time, the inclined front support can resist the horizontal deformation of the retaining while also counter-pressing the pit bottom soil.

[0058] The technical principles of the self-stabilizing foundation pit support structure mainly include the diagonal bracing effect, the rigid frame effect and the heave reduction effect. The diagonal bracing effect refers to the diagonal forward bracing piles providing bearing capacity by cooperating with the pit bottom soil, and controlling the tendency of the retaining piles to deform into the pit through the top pressure beam connected to the foundation pit retaining, providing resistance to the soil pressure outside the pit; the rigid frame effect refers to the use of a combination of rows of piles, diagonal piles and top pressure beams to form an over-static rigid frame structure to improve the stability and anti-overturning ability of the foundation pit; the heave reduction effect refers to the diagonal forward bracing piles working together with the soil in the pit to counter-press the pit bottom soil, which can reduce the heave deformation of the pit bottom soil caused by the foundation pit excavation, while maintaining the stress state of the pit bottom soil and increasing the soil pressure in the passive zone.

[0059] The advantages of self-stabilizing foundation pit support technology are mainly reflected in two aspects: (1) High efficiency: This technology uses the soil in the pit as the support point, combining soil trenching and reinforcement cushioning, which greatly saves the construction and maintenance time of traditional support structures; at the same time, the excavation stage realizes the large-space rapid construction of the foundation pit project without horizontal internal support, which solves the technical deficiencies of the current foundation pit project, such as the long construction and maintenance cycle of a large number of reinforced concrete supports and the low efficiency of foundation pit excavation, significantly improves construction efficiency and saves construction time. (2) Low resource consumption. This technology uses a small number of inclined piles instead of dense reinforced concrete supports, which greatly reduces the consumption of temporary reinforced concrete structural materials in existing similar technologies, saves energy and reduces emissions while significantly reducing engineering construction costs, and solves the environmental problems of the removal of reinforced concrete supports in existing similar technologies, such as construction waste, noise nuisance, and dust harming health.

[0060] Step 2: Collect the mechanical parameters and environmental parameters of the foundation pit, the mechanical parameters are soil pressure, foundation pit deformation, soil shear strength and vibration acceleration, and the environmental parameters are groundwater level and environmental humidity;

[0061] In this embodiment, the specific logic of collecting soil pressure data is as follows: using a formation pressure sensor to record the soil pressure at the bottom of the foundation pit in real time, and recording the soil pressure value as P t ;

[0062] The specific logic of collecting the foundation pit deformation data is as follows: displacement meters are set at characteristic points around the foundation pit to monitor the foundation pit deformation data in real time, which is recorded as Δh, wherein the deformation data is the deformation data relative to the original foundation pit;

[0063] The specific logic of collecting soil shear strength data is as follows: a certain volume of undisturbed soil sample is collected from the foundation pit site, prepared into a standard specimen, the specimen is placed in a uniaxial compression testing machine, axial load is gradually applied, stress and strain are measured, and a stress-strain curve is drawn. The elastic modulus E of the soil is obtained from the linear part of the stress-strain curve, i.e., the initial slope. p ;

[0064] A certain volume of undisturbed soil sample is collected from the site and prepared into a standard specimen. The specimen is placed in a uniaxial compression testing machine. During the compression process, the axial deformation and lateral deformation are measured, and the Poisson's ratio of the soil is calculated according to the following formula:

[0065]

[0066] Where v is the Poisson's ratio of the soil, ε l is the transverse strain, ε a is the axial strain;

[0067] Axial strain ε aIt is the ratio of the deformation along the load direction to the original length, and the calculation formula is:

[0068]

[0069] Among them, ε a is the axial strain, ΔL is the axial deformation, that is, the length after deformation minus the original length; L0 is the original length; the transverse strain is the ratio of the deformation perpendicular to the load direction to the original length, and the calculation formula is:

[0070]

[0071] Among them, ε l is the lateral strain, ΔD is the lateral deformation, that is, the length after deformation minus the original length; D0 is the original length; the shear modulus G of the soil is calculated using the following formula:

[0072]

[0073] Among them, G is the shear strength of soil, E p is the elastic modulus of the soil, v is the Poisson’s ratio of the soil;

[0074] The specific logic of collecting vibration acceleration data is as follows: fix the accelerometer on the self-stabilizing foundation pit support structure, and measure the acceleration in the three directions of x-axis, y-axis and z-axis respectively, which are recorded as A x , A y , A z ;

[0075] The specific logic of collecting groundwater level data is as follows: monitoring wells are set up around the foundation pit, well pipes are installed to enter the groundwater layer, a water level meter is placed vertically into the well and slowly lowered until it touches the water surface, and the measured depth is recorded, that is, the vertical distance from the wellhead to the water surface, recorded as H. total ; Record the absolute height of the wellhead, that is, the absolute height of the bottom of the foundation pit, denoted as H lg ;

[0076] Calculate the groundwater level using the following formula:

[0077] H w =H lg -H total

[0078] Among them, H w is the groundwater level, H lg is the absolute height of the wellhead, H total The depth measured from the wellhead to the water surface;

[0079] A hygrometer is used to collect real-time humidity data around the foundation pit, denoted as S. The collected humidity is compared with the preset humidity assessment threshold. If it exceeds the threshold range, the difference between the current humidity and the preset threshold is calculated, denoted as ΔS; if it does not exceed the threshold range, it will not be included in the subsequent calculation of the comprehensive environmental index.

[0080] Step 2 provides a comprehensive and detailed data basis for subsequent analysis by systematically collecting the mechanical parameters and environmental parameters of the foundation pit. This method not only covers the physical and mechanical properties of the soil, but also considers the impact of environmental factors on the stability of the foundation pit, making the evaluation more accurate and reliable, thereby ensuring that the support design is highly relevant to the actual situation. Compared with the existing technology, the advantage of step 2 lies in its multi-dimensional data collection method, which can more comprehensively reflect the actual working conditions of the foundation pit. Traditional methods often focus on a single parameter or lack sufficient environmental considerations, resulting in incomplete evaluation results. By combining mechanical and environmental parameters, potential risks and unstable factors can be identified more accurately, thereby improving the accuracy and effectiveness of foundation pit monitoring.

[0081] In this patent solution, the implementation of step 2 provides the necessary data support for the subsequent generation of comprehensive environmental index, deformation rate and vibration intensity. This data-driven process can ensure the scientificity and accuracy of real-time monitoring and evaluation, making the overall solution more flexible and effective in dealing with changes in the foundation pit, thereby improving the safety of the foundation pit and the construction efficiency. Through the effective use of this information, the feedback mechanism can be triggered in time, necessary adjustments can be made, and the stability of the foundation pit can be further guaranteed.

[0082] Step 3: Generate a comprehensive environmental index based on the dimensionless soil pressure, soil shear strength, groundwater level and environmental humidity data; generate a deformation rate based on the dimensionless foundation pit deformation data; and generate a vibration intensity based on the dimensionless vibration acceleration data;

[0083] In this embodiment, the formula for generating the comprehensive environmental index is:

[0084]

[0085] Among them, Str is the comprehensive environmental index, G is the shear strength of soil, P is t is the soil pressure value, H w is the groundwater level, ΔS is the difference between humidity and the preset threshold, C1 is the first constant correction index; when the soil pressure P tWhen G increases, it may cause deformation or slippage of the foundation pit wall, so the comprehensive environmental index Str decreases; the shear strength of the soil is the ability of the soil to resist shear failure. The higher the shear strength, the better the stability of the foundation pit, which can better resist slippage caused by soil pressure or external load. Therefore, when G increases, the comprehensive environmental index Str increases; the increase in groundwater level causes an increase in buoyancy, which may significantly reduce the effective stress of the soil, thereby reducing the shear strength of the soil and affecting the stability of the foundation pit. Therefore, when H w When ΔS increases, the comprehensive environmental index Str decreases; humidity changes can affect the physical and chemical properties of the soil, such as the expansion and compressibility of the soil, as well as the strength and permeability of the soil. Therefore, when ΔS increases, the comprehensive environmental index Str decreases; that is, G is positively correlated with Str, P t , H w , ΔS is negatively correlated with Str.

[0086] The deformation rate refers to the vertical deformation rate of the foundation pit and its surrounding soil within a specific time interval. The formula for generating the deformation rate is:

[0087]

[0088] Among them, Def is the deformation rate, Δh(t) is the deformation at the current moment, Δh(t-1) is the deformation at the previous moment, and Δt is the time interval;

[0089] The generated vibration intensity is based on the formula:

[0090]

[0091] Where Vib is the vibration intensity, A x , A y , A z are the components of acceleration on the x-axis, y-axis, and z-axis respectively.

[0092] Step 3 generates a comprehensive environmental index, deformation rate, and vibration intensity through dimensionless processing, making the comparison and analysis between different parameters more intuitive and scientific. This processing method can eliminate the influence of dimensions, allowing various complex soil and environmental factors to be evaluated under the same standard, thereby improving the comparability of data and the accuracy of analysis. Compared with the existing technology, the advantage of step 3 lies in its standardized data processing method, which enables multiple influencing factors to be effectively integrated and present the overall stability status of the foundation pit. This systematic approach avoids the errors caused by parameter differences in traditional evaluations, can provide a more comprehensive safety assessment, and provides a stronger basis for decision-making.

[0093] In the patent solution, the implementation of Step 3 lays the foundation for the generation of the foundation pit stability coefficient, ensuring the scientificity and effectiveness of subsequent safety assessments and risk analyses. By integrating multiple parameters to generate a comprehensive index, this step can provide specific evaluation criteria for the real-time monitoring system, enabling the overall solution to quickly respond when facing an unsafe state, making effective parameter adjustments and structural optimizations, thereby further enhancing the safety and construction efficiency of the foundation pit.

[0094] Step 4: Generate the foundation pit stability coefficient based on the comprehensive environmental index, deformation rate, and vibration intensity, and compare it with a preset safety threshold. When an unsafe state is detected, trigger a feedback mechanism to adjust the parameters of the support structure in real time.

[0095] In this embodiment, the formula for generating the foundation pit stability coefficient is as follows:

[0096]

[0097] Where FS is the foundation pit stability coefficient, Str is the comprehensive environmental index, α is its preset proportional coefficient, Def is the deformation rate, β is its preset proportional coefficient, Vib is the vibration intensity, γ is its preset proportional coefficient, and α > β > γ > 0. This is because understanding the bearing capacity of the soil mass and the impact of environmental changes on the foundation pit is an important basis for evaluating stability. In the case of being close to a traffic artery or a large construction project, the impact of the vibration intensity may be significant, and its weight will increase at this time. However, for a foundation pit far from the vibration source, the impact of vibration may be relatively small. C2 is the second constant correction index; when the comprehensive environmental index increases, it indicates that the comprehensive environmental conditions around the foundation pit improve, and the foundation pit stability coefficient FS increases; when the deformation rate Def or the vibration intensity Vib increases, the foundation pit stability coefficient FS decreases; that is to say, Str and FS are positively correlated, and Def and Vib are negatively correlated with FS.

[0098] The process of generating the foundation pit stability coefficient based on the stress index, deformation rate, and vibration intensity and comparing it with the preset safety threshold is specifically as follows:

[0099] When FS ≥ FY, it means that the foundation pit stability coefficient is within the preset safety threshold range, that is, the foundation pit is in a safe state, and continue to monitor the foundation pit;

[0100] When FS < FY, it means that the foundation pit stability coefficient is less than the preset safety threshold, that is, the foundation pit is in an unsafe state. Immediately organize engineers to conduct an on-site assessment of the foundation pit, confirm the cause of the unsafe state, and take corresponding measures;

[0101] Where FS is the foundation pit stability coefficient, and FY is the preset safety threshold.

[0102] Compared with the existing technology, the advantage of step 4 is that it can realize real-time monitoring and feedback mechanism, so that the monitoring data is not only a passive record, but also actively drives the adjustment of design and construction strategies. Traditional methods often lack dynamic response, resulting in the inability to adjust in time when deformation or other problems occur, increasing construction risks. Through the real-time adjustment mechanism, the probability of accidents can be significantly reduced, and the safety and efficiency of construction can be improved.

[0103] In this patent solution, the implementation of step 4 provides flexibility and adaptability for the overall solution, so that timely adjustments can be made according to actual conditions during the construction process. This mechanism can not only optimize resource allocation and reduce unnecessary material and manpower input, but also effectively respond to emergencies and ensure the smooth progress of foundation pit construction, thereby further improving the overall safety and economy of the project.

[0104] The specific values ​​of α, β and γ in the formula are generally determined by technical personnel in this field according to actual conditions. The technical personnel in this field collect multiple groups of sample data, and set corresponding preset proportional coefficients for each group of sample data. The preset proportional coefficients and the collected sample data are substituted into the formula. Through repeated experiments and parameter adjustments, the accuracy of the model output and the rationality of the results are observed, and these factor coefficients are gradually adjusted. The performance and effect of the model under different parameter settings are compared to find the optimal coefficient combination, and the calculated factor coefficients are screened and averaged to obtain the values ​​of α, β and γ.

[0105] In addition, the size of the preset factor coefficient is to quantify each parameter to obtain a specific value. In order to facilitate subsequent comparison, the size of the coefficient depends on the amount of sample data and the preset proportional coefficient initially set by technical personnel in this field for each set of sample data. It is not unique as long as it does not affect the proportional relationship between the parameter and the quantized value.

[0106] The above formulas are all dimensionless and numerical calculations. The formula is a formula for the most recent real situation obtained by collecting a large amount of data and performing software simulation. The preset parameters in the formula are set by technicians in this field according to actual conditions.

[0107] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0108] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0109] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A method for optimizing the design of a self-stabilizing support system for a foundation pit, characterized in that: The specific steps include: Step 1: Adopt self-stabilizing foundation pit support structure technology, use inclined forward support piles instead of reinforced concrete horizontal support, use inclined forward support piles to provide resistance, and achieve balance with the soil pressure outside the pit; Step 2: Collect the mechanical parameters and environmental parameters of the foundation pit, the mechanical parameters are soil pressure, foundation pit deformation, soil shear strength and vibration acceleration, and the environmental parameters are groundwater level and environmental humidity; Step 3: Generate a comprehensive environmental index based on the dimensionless soil pressure, soil shear strength, groundwater level and environmental humidity data; generate a deformation rate based on the dimensionless foundation pit deformation data; generate a vibration intensity based on the dimensionless vibration acceleration data; Step 4: Generate the foundation pit stability coefficient based on the comprehensive environmental index, deformation rate and vibration intensity, and compare it with the preset safety threshold. When an unsafe state is detected, the feedback mechanism is triggered to adjust the parameters of the supporting structure in real time.

2. The optimization design method of a self-stabilizing support system for a foundation pit according to claim 1 is characterized in that: The self-stabilizing foundation pit support structure technology adopted is specifically an emerging support technology that adopts inclined front support piles and rear pull rods to replace horizontal internal supports, and is combined with retaining piles, reinforcement bodies, ring beams and reinforced cushion layers. The self-stabilizing foundation pit support technology utilizes the resistance provided by the inclined front support, which is connected with the retaining piles to form a self-stabilizing structure to control the horizontal displacement of the retaining piles. When the retaining has a tendency to rotate, the self-stabilizing structure is compressed by the front support, and the retaining piles are pulled out to jointly generate rotational resistance. At the same time, the inclined front support can resist the horizontal deformation of the retaining and also counter-press the pit bottom soil.

3. The optimization design method of a self-stabilizing support system for a foundation pit according to claim 1 is characterized in that: The specific logic of collecting soil pressure data is as follows: using a formation pressure sensor to record the soil pressure at the bottom of the foundation pit in real time, and recording the soil pressure value as P t ; The specific logic of collecting the foundation pit deformation data is as follows: displacement meters are set at characteristic points around the foundation pit to monitor the foundation pit deformation data in real time, which is recorded as Δh; The specific logic of collecting soil shear strength data is as follows: a certain volume of undisturbed soil sample is collected from the foundation pit site, prepared into a standard specimen, the specimen is placed in a uniaxial compression testing machine, axial load is gradually applied, stress and strain are measured, and a stress-strain curve is drawn. The elastic modulus E of the soil is obtained from the linear part of the stress-strain curve, i.e., the initial slope. p ; A certain volume of undisturbed soil sample is collected from the site and prepared into a standard specimen. The specimen is placed in a uniaxial compression testing machine. During the compression process, the axial deformation and lateral deformation are measured, and the Poisson's ratio of the soil is calculated according to the following formula: Where v is the Poisson's ratio of the soil, ε l is the transverse strain, ε a is the axial strain; Axial strain ε a It is the ratio of the deformation along the load direction to the original length, and the calculation formula is: Among them, ε a is the axial strain, ΔL is the axial deformation, i.e. the length after deformation minus the original length; L0 is the original length; Transverse strain is the ratio of the deformation perpendicular to the load direction to the original length, and the calculation formula is: Among them, ε l is the transverse strain, ΔD is the transverse deformation, i.e. the length after deformation minus the original length; D0 is the original length; The shear modulus G of the soil is calculated using the following formula: Among them, G is the shear strength of soil, E p is the elastic modulus of the soil, v is the Poisson’s ratio of the soil; The specific logic of collecting vibration acceleration data is as follows: fix the accelerometer on the self-stabilizing foundation pit support structure, and measure the acceleration in the three directions of x-axis, y-axis and z-axis respectively, which are recorded as A x , A y , A z ; The specific logic of collecting groundwater level data is as follows: monitoring wells are set up around the foundation pit, well pipes are installed to enter the groundwater layer, a water level meter is placed vertically into the well and slowly lowered until it touches the water surface, and the measured depth is recorded, that is, the vertical distance from the wellhead to the water surface, recorded as H. total ; Record the absolute height of the wellhead, that is, the absolute height of the bottom of the foundation pit, denoted as H lg ; Calculate the groundwater level using the following formula: H w =H lg -H total Among them, H w is the groundwater level, H lg is the absolute height of the wellhead, H total The depth measured from the wellhead to the water surface; A hygrometer is used to collect real-time humidity data around the foundation pit, denoted as S. The collected humidity is compared with the preset humidity assessment threshold. If it exceeds the threshold range, the difference between the current humidity and the preset threshold is calculated, denoted as ΔS; if it does not exceed the threshold range, it will not be included in the subsequent calculation of the comprehensive environmental index.

4. The optimization design method of a self-stabilizing support system for a foundation pit according to claim 1 is characterized in that: The formula for generating the comprehensive environmental index is as follows: Among them, Str is the comprehensive environmental index, G is the shear strength of soil, P is t is the soil pressure value, H w is the groundwater level, ΔS is the difference between the humidity and the preset threshold, and C1 is the first constant correction index; The deformation rate refers to the vertical deformation rate of the foundation pit and its surrounding soil within a specific time interval. The formula for generating the deformation rate is: Among them, Def is the deformation rate, Δh(t) is the deformation at the current moment, Δh(t-1) is the deformation at the previous moment, and Δt is the time interval; The generated vibration intensity is based on the formula: Where Vib is the vibration intensity, A x , A y , A z are the components of acceleration on the x-axis, y-axis, and z-axis respectively.

5. The optimization design method of a self-stabilizing support system for a foundation pit according to claim 4 is characterized in that: The formula for generating the foundation pit stability coefficient is as follows: Among them, FS is the foundation pit stability coefficient, Str is the comprehensive environment index, α is its preset proportional coefficient, Def is the deformation rate, β is its preset proportional coefficient, Vib is the vibration intensity, γ is its preset proportional coefficient, and α > β > γ > 0, C2 is the second constant correction index.

6. The optimization design method of a self-stabilizing support system for a foundation pit according to claim 1 is characterized in that: The process of generating the foundation pit stability coefficient based on the stress index, deformation rate, and vibration intensity and comparing it with the preset safety threshold is specifically as follows: When FS ≥ FY, it indicates that the foundation pit stability coefficient is within the preset safety threshold range, that is, the foundation pit is in a safe state, and the monitoring of the foundation pit continues to be maintained; When FS < FY, it indicates that the foundation pit stability coefficient is less than the preset safety threshold, that is, the foundation pit is in an unsafe state. Immediately organize engineers to conduct an on-site assessment of the foundation pit, confirm the cause of the unsafe state, and take corresponding measures; Among them, FS is the foundation pit stability coefficient, and FY is the preset safety threshold.

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