Urban newly-built subway line selection safety risk assessment method and system

Abstract

The invention provides an urban newly-built subway line selection safety risk assessment method and system. The method comprises the steps that an existing building (structure) pile foundation loss permissible model is established; establishing a dynamic and static mechanical response model of the soft soil body through data statistical analysis and equation fitting; establishing a distance relation model between a dynamic stress field generated by metro operation and the metro through numerical simulation; and the allowable existing building pile foundation loss, the soft soil mass mechanical response and the distance relation between the subway operation stress field and the subway are synthesized, the safe distance value range is obtained, and line selection evaluation of the newly-built subway is supported. According to the method, through collection, arrangement and analysis fitting of a large amount of data information, summarization of the high-risk area of the newly-built metros in the high-density city in the soft soil area is achieved, and effective guidance is provided for planning and design of the newly-built metros in the soft soil area under the condition that existing buildings are considered.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering structure analysis and safety assessment, and in particular to a method and system for safety risk assessment of new subway line selection in a high-density city in a soft soil area taking into account existing building pile foundations, and also to a corresponding computer assessment device and a computer-readable storage medium. Background Art

[0002] With the rapid development of cities, buildings (structures) are becoming more and more dense, and the density is gradually increasing. When building a new subway, it is often necessary to consider the impact of buildings (structures) along the subway line. In soft soil areas, due to the poor engineering characteristics of soft soil, the dynamic load generated by the long-term operation of the subway will have an impact on the surrounding soft soil, which may reduce the safety and reliability of the pile foundations of adjacent existing buildings, thereby affecting the safety of existing buildings. Therefore, when building a new subway in a high-density city in a soft soil area, it is necessary to conduct a safety risk assessment from the perspective of not affecting the safety of buildings (structures) along the subway line, so as to avoid the adverse engineering impacts brought by the new subway.

[0003] After searching, it was found that the Chinese invention patent "Rail Transit Route Selection Evaluation and Cost Optimization Method for Geological Environmental Risks" with authorization announcement number CN111553509B reduces the cost of rail transit construction by evaluating the level of geological risks covered by the rail transit route selection plan and the cost and construction period of risk treatment. The Chinese invention patent "Surface Settlement Prediction Method for Mountain City Subway Tunnels Based on Three-Dimensional Geological Model" with application number CN117744306A uses actual drilling data to construct a three-dimensional geological model of the region, analyzes and predicts surface settlement of subway tunnel construction, and realizes the optimization of subway route selection and tunnel construction plans that take into account the influence of surface settlement. However, these methods do not consider the impact of existing buildings (structures).

[0004] There are many high-density cities with existing buildings (structures) in soft soil areas. The characteristics of soft soil need to be considered when selecting subway lines. At the same time, it is also crucial to fully consider the impact of existing buildings (structures) on the safety of subway line selection. At present, no description or report of similar technology to the present invention has been found, and similar information at home and abroad has not been collected. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method and system for safety risk assessment of new subway line selection in high-density cities in soft soil areas taking into account existing building pile foundations, and also provides a corresponding computer assessment device and computer-readable storage medium.

[0006] According to one aspect of the present invention, a method for safety risk assessment of new urban subway line selection is provided, comprising:

[0007] Obtain information on design subway parameters, as well as information on strata and existing buildings along the proposed subway line;

[0008] Establishing an allowable model for pile foundation loss of existing buildings based on the existing building information and the stratum information along the proposed subway line;

[0009] According to the stratum information along the proposed subway line, a dynamic and static mechanical response model of soft soil is established;

[0010] According to the designed subway parameter information and the stratum information along the proposed subway line, a distance relationship model between the dynamic stress field generated by subway operation and the subway is established through numerical simulation;

[0011] By combining the pile foundation loss allowable model, mechanical response model and distance relationship model, the safe distance range between the pile foundation of the existing building and the subway is obtained, and the line selection safety of the new subway is evaluated.

[0012] Preferably, establishing an allowable model for pile foundation loss of existing buildings based on the existing building information and the stratum information along the proposed subway line includes:

[0013] Considering the unfavorable engineering characteristics of soft soil in soft soil areas, the vertical bearing capacity of pile foundation Q is obtained according to the building characteristics in the existing building information. uk The standard formula is:

[0014] Q uk =Q sk +Q pk =u∑q sik l i +q pk A p

[0015] Among them, Q sk is the pile side bearing capacity, Q pk is the bearing capacity of the pile end, u is the circumference of the pile body, q sik is the standard value of the ultimate lateral resistance of the i-th layer of soil on the pile side, let q sik =α·S u , α is the empirical coefficient, S u is the undrained strength, l i is the length of the pile foundation in the i-th layer of soil, q pk is the standard value of the ultimate end resistance, A p is the cross-sectional area of ​​the pile end;

[0016] The long-term operation of the new subway will affect q sik Thereby reducing the pile side bearing capacity Q sk , define the strength reduction rate of the pile side bearing capacity as λ, then:

[0017] Q sk ′=λ·Q sk

[0018] Among them, Q sk ′ is the bearing capacity of pile side after considering the dynamic response of subway operation and the reduction;

[0019] Assume that the pile side bearing capacity Q sk Percentage of vertical bearing capacity of pile foundation Q uk The contribution ratio of is p1, then:

[0020]

[0021] Considering the reduction of soil strength around the pile, the reduced vertical ultimate bearing capacity of the single pile Q′ can be obtained: uk for:

[0022]

[0023] Let Q uk The allowable bearing capacity loss percentage is p2, and the limiting formula for the allowable strength reduction rate is:

[0024] Q′ uk ≥(1-p2)Q uk

[0025] Then we have:

[0026]

[0027] Preferably, the step of establishing a dynamic and static mechanical response model of soft soil mass according to the stratum information along the proposed subway line and the design subway parameter information includes:

[0028] According to the stratum information along the proposed subway line, the confining pressure σp of the soft soil is obtained. According to the design speed v in the design subway parameter information and the length L of the pile foundation of the existing buildings along the proposed subway line, the dynamic stress field σ generated by the dynamic load of the subway train on the surrounding soil and pile foundation is obtained through numerical calculation. d Distribution;

[0029] Establish the dynamic shear modulus G of soft soil d and undrained strength S u ratio and dynamic stress-strain γ d The relationship between them is: Where f(γ d ) describes G d , S u and γ d The relationship between them is: a1 and b1 are fitting parameters;

[0030] Establish dynamic shear strain γ d The relationship between γ and dynamic stress ratio CSR is obtained by fitting: d =f(CSR); where f(CSR) describes γ d The relationship between it and CSR is: CSR=σ d / σ p , a2 and b2 are fitting parameters;

[0031] Combined with the relation Q uk =Q sk +Q pk =u∑q sik l i +q pk A p , Q sk ′=λ·Q sk and q sik =α·S u , to obtain Among them, S ua In order to consider the undrained strength after the reduction due to the subway dynamic load, S u0 is the initial undrained strength without considering the reduction, γ d0 is an infinitesimal quantity, γ da is the dynamic shear strain of the soil at position a under dynamic stress, G da For γ d =γ da The dynamic shear modulus, S ua For γ d =γ da Undrained shear strength;

[0032] The softening coefficient δ is introduced and defined as the dynamic shear modulus G obtained under the Nth vibration cycle condition. dN The dynamic shear modulus G under the first vibration cycle condition d1 The ratio of δ = G dN / G d1 , the relationship between the softening coefficient δ and the dynamic stress ratio CSR is obtained and fitted to obtain the relationship: δ = f(CSR); where f(CSR) describes the relationship between δ and CSR as follows: δ = f(CSR) = a3·CSR+b3, where a3 and b3 are fitting parameters;

[0033] According to S u The change reflects the pile side bearing capacity Q sk The change of undrained strength brought about by different dynamic stress ratios is finally established as follows:

[0034]

[0035] Combined Relationship γd=f(CSR) and δ=f(CSR), we get The relationship between the strength reduction factor λ and the dynamic stress ratio CSR is established:

[0036]

[0037] Combined with formula Q′ uk ≥(1-p2)Q uk ,Right now The range of CSR can be derived. p Under certain circumstances, CSR=σ d / σ p The dynamic stress field σ is obtained d The value range of .

[0038] Preferably, the step of establishing a distance relationship model between the dynamic stress field generated by subway operation and the subway through numerical simulation based on the designed subway parameter information and the stratum information along the proposed subway line includes:

[0039] Based on the stratigraphic information along the proposed subway line, the confining pressure of soft soil mass σ is obtained. p According to the design speed v in the design subway parameter information and the length L of the pile foundation of the existing buildings along the proposed subway line, the dynamic stress field σ generated by the dynamic load of the subway train on the surrounding soil and pile foundation is obtained through numerical calculation d Distribution, considering the distance D between the building pile foundation and the new subway, the distance relationship between the dynamic stress field of soft soil and the subway is established as: d =f(D); where f(D) describes σ d The relationship between σ and D is d =f(D)=a4·D+b4, a4 ​​and b4 are fitting parameters.

[0040] Preferably, the comprehensive pile foundation loss allowable model, mechanical response model and distance relationship model are used to obtain the safe distance value range between the pile foundation of the existing building (structure) and the subway, including:

[0041] Combined with the formula σ d =f(D) and dynamic stress field σ d The value range of D is determined, and based on the value range of D, the high-risk areas are marked with the pile foundation of existing buildings (structures) as the base point, which provides a reference for the selection of new urban subway lines.

[0042] According to another aspect of the present invention, a safety risk assessment system for selecting a new urban subway line is provided, comprising:

[0043] A data acquisition module, which is used to obtain the design subway parameter information and the stratum information and existing building information along the proposed subway line;

[0044] A pile foundation loss construction module, which is used to establish an allowable model for pile foundation losses of existing buildings based on the existing building information and the stratum information along the proposed subway line;

[0045] A mechanical response building module, which is used to build a dynamic and static mechanical response model of soft soil according to the stratum information along the proposed subway line;

[0046] A distance relationship building module, which is used to establish a distance relationship model between the dynamic stress field generated by subway operation and the subway through numerical simulation according to the designed subway parameter information and the stratum information along the proposed subway line;

[0047] The safety assessment module is used to integrate the pile foundation loss allowable model, mechanical response model and distance relationship model to obtain the safe distance value range between the pile foundation of the existing building and the subway, and evaluate the line selection safety of the new subway.

[0048] According to a third aspect of the present invention, there is provided a computer evaluation device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, can be used to execute any one of the methods described above in the present invention, or to run the system described above in the present invention.

[0049] According to a fourth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, can be used to execute any of the methods described above in the present invention, or to run the system described above in the present invention.

[0050] Due to the adoption of the above technical solution, the present invention has at least one of the following beneficial effects compared with the prior art:

[0051] The safety risk assessment method and system for the line selection of a new urban subway provided by the present invention fully considers the safety of the pile foundations of existing buildings in soft soil areas, collects the pile foundation data of existing buildings along the new subway line, simulates the dynamic stress field of the subway operation, analyzes the data and fits the equations, fully considers the engineering adverse properties of soft soil, prompts the high-risk areas for the line selection of subway tunnels, and provides a reference for the line selection of subway tunnels.

[0052] The safety risk assessment method and system for the line selection of new urban subways provided by the present invention can be optimized according to actual working conditions, comprehensively considering the adverse engineering properties of soft soil and the impact of buildings (structures) adjacent to the subway, and helping planning and design personnel to fully understand the high-risk areas for subway line selection in high-density urban areas, making the subway line selection plan safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0054] Figure 1 The present invention is a flowchart of a safety risk assessment method for selecting a new urban subway line in one embodiment of the present invention.

[0055] Figure 2 It is a schematic diagram of the working content of the safety risk assessment method for selecting a new urban subway line in a preferred embodiment of the present invention.

[0056] Figure 3 The figure is a schematic diagram of the components of a safety risk assessment system for selecting a new urban subway line in one embodiment of the present invention. DETAILED DESCRIPTION

[0057] The following is a detailed description of the embodiments of the present invention: This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and a specific operation process are given. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

[0058] The existing safety risk assessments for new subway line selection do not consider the impact of existing buildings (structures). However, there are many high-density cities with existing buildings (structures) in soft soil areas. The characteristics of soft soil need to be considered when selecting subway lines, and it is also crucial to fully consider the impact of existing buildings (structures) on the safety of subway line selection. The present invention is aimed at the line selection problem of new subways in cities with high-density buildings in soft soil areas, and provides a safety risk assessment method for new subway line selection in cities. The method fully considers the long-term safety of existing building pile foundations in high-density cities in soft soil areas, and obtains the dynamic and static mechanical responses of soft soil bodies caused by long-term operation of subways through the collection of a large amount of data information on existing building pile foundations, simulation of the dynamic stress field of subway operation, data collation and analysis, and equation fitting, and establishes a high-risk area prompt for new subways, which realizes the summary of high-risk areas for new subways in high-density cities in soft soil areas, provides effective guidance for the planning and design of new subways in soft soil areas considering existing buildings, and provides support for subway line selection.

[0059] Specifically, as shown in FIG. 1 , the safety risk assessment method for selecting a new urban subway line provided in this embodiment may include the following operations:

[0060] S l, obtain the design subway parameter information and the stratum information and existing building (structure) information along the proposed subway line;

[0061] S2: Based on the information of existing buildings (structures) and the stratum information along the proposed subway line, establish the allowable model of pile foundation loss of existing buildings (structures);

[0062] S3, based on the stratigraphic information along the proposed subway line, establish a dynamic and static mechanical response model of soft soil;

[0063] S4, based on the designed subway parameter information and the stratum information along the proposed subway line, a model of the relationship between the dynamic stress field generated by subway operation and the distance between the subway is established through numerical simulation;

[0064] S5, integrate the pile foundation loss allowable model, mechanical response model and distance relationship model to obtain the safe distance range between the pile foundation of existing buildings (structures) and the subway, and evaluate the safety of the line selection of the new subway.

[0065] The technical solution provided by the above embodiment of the present invention is further described in detail below in combination with preferred implementation modes, specific application examples and drawings.

[0066] like Figure 2 As shown, in some preferred implementations, the safety risk assessment method for urban new subway line selection provided by the above embodiment of the present invention may further include the following operations:

[0067] S1, obtain the design subway parameters, strata along the proposed subway line, and existing building (structure) data.

[0068] S2. According to the characteristics of the building (structure), determine the safety control parameters of the existing pile foundation, such as the contribution ratio of the pile side bearing capacity to the pile end bearing capacity, the allowable bearing capacity loss, etc., and obtain the range of allowable strength reduction rate.

[0069] In some preferred implementations, the above S2, establishing an allowable model for pile foundation loss of existing buildings (structures) based on the existing building (structure) information and the stratum information along the proposed subway line, may further include the following operations:

[0070] Considering the adverse engineering characteristics of soft soil in soft soil areas, the vertical bearing capacity of pile foundation Q is obtained according to the building characteristics in the existing building information. uk The standard formula is:

[0071] Q uk =Q sk +Qpk =u∑q sik l i +q pk A p

[0072] Among them, Q sk is the pile side bearing capacity, Q pk is the bearing capacity of the pile end, u is the circumference of the pile body, q sik is the standard value of the ultimate lateral resistance of the i-th layer of soil on the pile side, let q sik =α·S u , α is the empirical coefficient, S u is the undrained strength, l i is the length of the pile foundation in the i-th layer of soil, q pk is the standard value of the ultimate end resistance, A p is the cross-sectional area of ​​the pile end;

[0073] The long-term operation of the new subway will affect q sik Thereby reducing the pile side bearing capacity Q sk , define the strength reduction rate of the pile side bearing capacity as λ, then:

[0074] Q sk ′=λ·Q sk

[0075] Among them, Q sk ′ is the bearing capacity of pile side after considering the dynamic response of subway operation and the reduction;

[0076] Assume that the pile side bearing capacity Q sk Percentage of vertical bearing capacity of pile foundation Q uk The contribution ratio of is p1, then:

[0077] Q sk =p1×Q uk

[0078]

[0079] Considering the reduction of soil strength around the pile, the reduced vertical ultimate bearing capacity of the single pile Q′ can be obtained: uk for:

[0080]

[0081] Let Q uk The allowable bearing capacity loss percentage is p2, and the limiting formula for the allowable strength reduction rate is:

[0082] Q′ uk ≥(1-p2)Q uk

[0083] Then we have:

[0084]

[0085] Pile side bearing capacity in soft soil area Q sk Generally speaking, the vertical bearing capacity Q uk In a specific application example, taking Shanghai as an example, the pile side bearing capacity Q sk Generally speaking, the vertical bearing capacity Q uk 80% of the contribution, take Q sk =80%×Q uk ; then Q uk =Q sk +Q pk =Q sk +0.25Q sk =1.25Q sk ; Considering the reduction of soil strength around the pile, Q sk ′=λ·Q sk , the calculation formula for the reduced vertical ultimate bearing capacity of a single pile is Q′ uk =Q′ sk +0.25Q sk =λ·Q sk +0.25Q sk =(λ+0.25)Q sk . Set Q uk If the loss is more than 30%, there will be a danger alarm for the existing building, that is, p2 = 0.3, so there is a limiting formula:

[0086] That is, λ≥0.625

[0087] S3, investigate the physical and mechanical properties of soft soil in the stratum, including confining pressure, elastic modulus, softening coefficient, dynamic stress-strain relationship, etc., and establish the dynamic shear modulus G of soft soil d Ratio of undrained strength to u , dynamic strain γ d , softening coefficient δ, dynamic stress ratio CSR and other parameters.

[0088] In some preferred implementations, the above S3, establishing a dynamic and static mechanical response model of soft soil according to the stratum information along the proposed subway line and the design subway parameter information, may further include the following operations:

[0089] According to the stratum information along the proposed subway line, it is known that the confining pressure of soft soil σ p According to the design speed v in the design subway parameter information and the length L of the pile foundation of the existing buildings along the proposed subway line, the dynamic stress field σ generated by the dynamic load of the subway train on the surrounding soil and pile foundation is obtained through numerical calculation d Distribution;

[0090] Through data statistical analysis and equation fitting, the dynamic shear modulus G of soft soil is established. d and undrained strength S u ratio and dynamic stress-strain γ d The relationship between them is: Where f(γ d ) describes G d , S u The relationship between and γd is: a1 and b1 are fitting parameters;

[0091] Through data statistical analysis and equation fitting, the dynamic shear strain γ is established. d The relationship between γ and dynamic stress ratio CSR is obtained by fitting: d =f(CSR); where f(CSR) describes γ d The relationship between it and CSR is: CSR=σ d / σ p , a2 and b2 are fitting parameters;

[0092] Undrained strength S u The standard value of the ultimate lateral resistance of the i-th layer of soil on the pile side is qsi k The standard value of the ultimate lateral resistance of the i-th layer of soil on the pile side is qsi k The variation of undrained strength S u The change of is directly reflected; combined with the relationship Q uk =Q sk +Q pk =u∑q sik l i +q pk A p , Q sk ′=λ·Q sk and q sik =α·S u , can be obtained Among them, S ua In order to consider the undrained strength after the reduction due to the subway dynamic load, S u0 is the initial undrained strength without considering the reduction, γ d0 is an infinitesimal quantity, γ da is the dynamic shear strain of the soil at position a under dynamic stress, G da For γ d =γ da The dynamic shear modulus, S ua For γ d =γ aa Undrained shear strength;

[0093] Through statistical analysis of data and equation fitting, the softening coefficient δ is introduced and defined as the dynamic shear modulus G obtained under the Nth vibration cycle condition. dN The dynamic shear modulus G under the first vibration cycle condition d1 The ratio of δ = G dN / G d1 , the relationship between the softening coefficient δ and the dynamic stress ratio CSR is obtained and fitted to obtain the relationship: δ = f(CSR); where f(CSR) describes the relationship between δ and CSR as follows: δ = f(CSR) = a3·CSR+b3, where a3 and b3 are fitting parameters;

[0094] According to S u The change reflects the pile side bearing capacity Q sk The change of , and finally the law of undrained strength change caused by different dynamic stress ratios is established as follows:

[0095]

[0096] Combined Relationship And δ = f(CSR), we get The relationship between the strength reduction factor λ and the dynamic stress ratio CSR is established:

[0097]

[0098] Combined with the restriction formula Q′ uk ≥(1-p2)Q uk ,Right now The range of CSR can be derived. p Under certain circumstances, CSR=σ d / σ p The dynamic stress field σ is obtained d The value range of .

[0099] In a specific application example, the softening coefficient is used for correlation. The relationship between the softening coefficient δ and the dynamic stress ratio CSR δ = f (CSR) can be directly fitted according to the soft soil properties in different regions. Considering the size of the subway load, only the relationship within the range of CSR < 0.5 needs to be considered. Considering γ d0 is an infinitesimal quantity, we can let γ d0 =1E-5, from the relationship in S3 we can get:

[0100]

[0101] S4. According to the stratum properties and subway design parameters (such as subway design speed, etc.), the dynamic stress field generated by subway operation is obtained through numerical simulation and other means, and the relationship between the dynamic stress field of soft soil and the distance from the subway is obtained.

[0102] In some preferred implementations, the above S4, based on the designed subway parameter information and the stratum information along the proposed subway line, establishes a distance relationship model between the dynamic stress field generated by the subway operation and the subway through numerical simulation, and may further include the following operations:

[0103] According to the formation information and the design subway parameter information (such as subway design speed, etc.), according to the formation information along the proposed subway line, the confining pressure σ of the soft soil is obtained. p According to the design speed v in the design subway parameter information and the length L of the pile foundation of the existing buildings along the proposed subway line, the dynamic stress field σ generated by the dynamic load of the subway train on the surrounding soil and pile foundation is calculated by numerical simulation method. d Distribution, considering the distance D between the building pile foundation location and the new subway, the relationship between the two is established as: d =f(D); where f(D) describes σ d The relationship between σ and D is d =f(D)=a4·D+b4, where a4 and b4 are fitting parameters. Furthermore, the confining pressure of soft soil σ p , subway design speed v and existing building pile foundation length L can be collected through engineering surveys, design drawings and other documents.

[0104] In a specific application example, taking Shanghai as an example, the average confining pressure of soft soil σ p =62kPa, the dynamic stress field can be expressed by a linear relationship, σ d =-0.0912D+2.6034, where a4=-0.0912, b4=2.6034.

[0105] S5, comprehensively considers pile foundation requirements, soil strength variation law, and subway operation dynamic stress field to obtain the safe distance between the existing building (structure) pile foundation and the subway. Based on the value range of D, the existing building (structure) pile foundation is used as the base point to mark high-risk areas and generate subway line selection risk area prompts.

[0106] In some preferred implementations, the above S5, integrating the pile foundation loss allowable model, the mechanical response model and the relationship model to obtain the safe distance value range between the pile foundation of the existing building (structure) and the subway, may further include the following operations:

[0107] Combined with the formula σ d =f(D) and dynamic stress field σ dThe value range of D is determined based on the value range of D. Based on the value range of D, the high-risk areas are marked with the pile foundation of the existing building (structure) as the base point. The high-risk areas that are divided should be avoided as much as possible when selecting new subway lines. Otherwise, other vibration isolation measures should be taken, which provides a reference for the selection of new subway lines in high-density cities in soft soil areas.

[0108] In a specific application example, taking Shanghai as an example, the permitted relationship of CSR that can be obtained is as follows:

[0109]

[0110] Combined with S4 formula σ d =-0.0912D+2.6034 and the definition of CSR CSR = σ d / σ p , we can get the value range of D:

[0111]

[0112] According to the value range of D, the pile foundation of existing buildings (structures) is used as the base point to mark high-risk areas and generate risk area prompts for subway line selection.

[0113] In the above-mentioned embodiment of the present invention, data statistical analysis is achieved by acquiring required data in the soft soil dynamic property file and performing statistical analysis.

[0114] Based on the same inventive concept, an embodiment of the present invention also provides a safety risk assessment system for selecting a new urban subway line.

[0115] Specifically, Figure 3 As shown, the urban new subway line selection safety risk assessment system provided by this embodiment may include the following modules:

[0116] Data acquisition module, which is used to obtain the design subway parameter information and the stratum information and existing building (structure) information along the proposed subway line;

[0117] Pile foundation loss construction module, which is used to establish the allowable model of pile foundation loss of existing buildings (structures) based on the information of existing buildings (structures) and the stratum information along the proposed subway line;

[0118] Mechanical response construction module, which is used to establish the dynamic and static mechanical response model of soft soil according to the stratum information along the proposed subway line;

[0119] A distance relationship building module, which is used to establish a distance relationship model between the dynamic stress field generated by subway operation and the subway through numerical simulation based on the designed subway parameter information and the stratum information along the proposed subway line;

[0120] Safety assessment module: This module is used to integrate the pile foundation loss allowable model, mechanical response model and distance relationship model to obtain the safe distance value range between the pile foundation of existing buildings (structures) and the subway, and evaluate the safety of the line selection of the new subway.

[0121] It should be noted that the steps in the method provided by the present invention can be implemented by using corresponding modules, devices, units, etc. in the system. Those skilled in the art can refer to the technical solution of the method to realize the composition of the system, that is, the embodiments in the method can be understood as preferred examples for constructing the system, which will not be elaborated here.

[0122] An embodiment of the present invention further provides a computer evaluation device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the device can be used to execute any method of the above-mentioned embodiments of the present invention, or to run any system of the above-mentioned embodiments of the present invention.

[0123] Optionally, the memory is used to store programs; the memory may include volatile memory (English: volatile memory), such as random-access memory (English: random-access memory, abbreviated: RAM), such as static random-access memory (English: static random-access memory, abbreviated: SRAM), double data rate synchronous dynamic random access memory (English: Double Data Rate Synchronous Dynamic Random Access Memory, abbreviated: DDR SDRAM), etc.; the memory may also include non-volatile memory (English: non-volatile memory), such as flash memory (English: flash memory). The memory is used to store computer programs (such as applications, functional modules, etc. that implement the above method), computer instructions, etc., and the above computer programs, computer instructions, etc. can be partitioned and stored in one or more memories. And the above computer programs, computer instructions, data, etc. can be called by the processor.

[0124] The above-mentioned computer programs, computer instructions, etc. may be stored in one or more memories in partitions, and the above-mentioned computer programs, computer instructions, data, etc. may be called by a processor.

[0125] The processor is used to execute the computer program stored in the memory to implement the various steps of the method or various modules of the system involved in the above embodiments. For details, please refer to the relevant descriptions in the above method and system embodiments.

[0126] The processor and the memory may be independent structures or integrated structures. When the processor and the memory are independent structures, the memory and the processor may be coupled and connected via a bus.

[0127] An embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it can be used to execute any method of the above embodiments of the present invention, or to run any system of the above embodiments of the present invention.

[0128] Among them, computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of computer programs from one place to another. The storage medium can be any available medium that can be accessed by a general or special-purpose computer. An exemplary storage medium is coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. Of course, the storage medium can also be an integral part of the processor. The processor and the storage medium can be located in an ASIC. In addition, the ASIC can be located in a user device. Of course, the processor and the storage medium can also be present in a communication device as discrete components.

[0129] The safety risk assessment method and system for the line selection of a new urban subway provided by the above-mentioned embodiment of the present invention fully considers the safety of the pile foundations of existing buildings in soft soil areas, collects the pile foundation data of existing buildings along the new subway line, simulates the dynamic stress field of the subway operation, and performs data analysis and equation fitting to fully consider the poor engineering properties of soft soil, and prompts the high-risk areas for the line selection of subway tunnels, providing a reference for the line selection of subway tunnels; it can be optimized according to the actual working conditions, comprehensively considers the poor engineering properties of soft soil and the influence of the buildings (structures) adjacent to the subway, and helps planning and design personnel to fully understand the high-risk areas for the line selection of subways in high-density areas in the city, so that the subway line selection plan is safer and more reliable.

[0130] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various modifications or variations within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A safety risk assessment method for selecting a new urban subway line, characterized in that: include: Obtain design subway parameter information as well as stratum information and existing building information along the proposed subway line; Establishing an allowable model for pile foundation loss of existing buildings based on the existing building information and the stratum information along the proposed subway line; According to the stratum information along the proposed subway line, a dynamic and static mechanical response model of soft soil is established; According to the designed subway parameter information and the stratum information along the proposed subway line, a distance relationship model between the dynamic stress field generated by subway operation and the subway is established through numerical simulation; By combining the pile foundation loss allowable model, mechanical response model and distance relationship model, the safe distance range between the pile foundation of the existing building and the subway is obtained, and the safety of the line selection of the new subway is evaluated.

2. The safety risk assessment method for selecting a new urban subway line according to claim 1 is characterized in that: The method of establishing a pile foundation loss allowable model for existing buildings based on the existing building information and the stratum information along the proposed subway line includes: Considering the unfavorable engineering characteristics of soft soil in soft soil areas, the vertical bearing capacity of pile foundation Q is obtained according to the building characteristics in the existing building information. uk The standard formula is: Q uk =Q sk +Q pk =u∑q sik l i +q pk A p Among them, Q sk is the pile side bearing capacity, Q ok is the bearing capacity of the pile end, u is the circumference of the pile body, q sik is the standard value of the ultimate lateral resistance of the i-th layer of soil on the pile side, let q sik =α·S u , α is the empirical coefficient, S u is the undrained strength, l i is the length of the pile foundation in the i-th layer of soil, q pk is the standard value of the ultimate end resistance, A p is the cross-sectional area of ​​the pile end; The long-term operation of the new subway will affect q sik Thereby reducing the pile side bearing capacity Q sk , define the strength reduction rate of the pile side bearing capacity as λ, then: Q sk ′=λ·Q sk Among them, Q sk ′ is the bearing capacity of pile side after considering the dynamic response of subway operation and the reduction; Assume that the pile side bearing capacity Q sk Percentage of vertical bearing capacity of pile foundation Q uk The contribution ratio of is p1, then: Considering the reduction of soil strength around the pile, the reduced vertical ultimate bearing capacity of the single pile Q′ can be obtained: uk for: Let Q uk The allowable bearing capacity loss percentage is p2, and the limiting formula for the allowable strength reduction rate is: Q′ uk ≥(1-p2)Q uk Then we have:

3. The safety risk assessment method for selecting a new urban subway line according to claim 1 is characterized in that: The method of establishing a dynamic and static mechanical response model of soft soil mass according to the stratum information along the proposed subway line and the design subway parameter information includes: According to the stratigraphic information along the proposed subway line, the confining pressure of soft soil mass σ is obtained. p According to the design speed v in the design subway parameter information and the length L of the pile foundation of the existing buildings along the proposed subway line, the dynamic stress field σ generated by the dynamic load of the subway train on the surrounding soil and pile foundation is obtained through numerical calculation d Distribution; Establish the dynamic shear modulus G of soft soil d and undrained strength S u ratio and dynamic shear strain γ d The relationship between them is: Among them, a1 and b1 are fitting parameters; Establish the dynamic shear strain γ d The relationship between the dynamic stress ratio CSR is fitted and the relationship is: Where CSR = σ d / σ p ; Where a2 and b2 are fitting parameters; Combined with the relation Q uk =Q sk +Q pk =u∑q sik l i +q pk A p , Q sk ′=λ·Q sk and q sik =α·S u , to obtain Among them, S ua In order to consider the undrained strength after the reduction due to the subway dynamic load, S u0 is the initial undrained strength without considering the reduction, γ d0 is an infinitesimal quantity, γ da is the dynamic shear strain of the soil at position a under dynamic stress, G da For γ d =γ da The dynamic shear modulus, S ua For γ d =γ da Undrained shear strength; The softening coefficient δ is introduced and defined as the dynamic shear modulus G obtained under the Nth vibration cycle condition. dN The dynamic shear modulus G under the first vibration cycle condition d1 The ratio of δ = G dN / G d1 , the relationship between the softening coefficient δ and the dynamic stress ratio CSR is obtained and fitted to obtain the relationship: δ = f (CSR) = a3 · CSR + b3, where a3 and b3 are fitting parameters; According to S u The change reflects the pile side bearing capacity Q sk The change of undrained strength brought about by different dynamic stress ratios is finally established as follows: Combined with the above relationship γ d =f(CSR) and δ=f(CSR), we get The relationship between the strength reduction factor λ and the dynamic stress ratio CSR is established: Combined with formula Q′ uk ≥(1-p2)Q uk ,Right now The range of CSR is derived. Under the known confining pressure σ p Under certain circumstances, CSR=σ d / σ p The dynamic stress field σ is obtained d The value range of .

4. The safety risk assessment method for selecting a new urban subway line according to claim 1 is characterized in that: The method of establishing a distance relationship model between the dynamic stress field generated by subway operation and the subway through numerical simulation based on the designed subway parameter information and the stratum information along the proposed subway line includes: Based on the stratigraphic information along the proposed subway line, the confining pressure of soft soil mass σ is obtained. p According to the design speed v in the design subway parameter information and the length L of the pile foundation of the existing buildings along the proposed subway line, the dynamic stress field σ generated by the dynamic load of the subway train on the surrounding soil and pile foundation is obtained through numerical calculation d Distribution, considering the distance D between the building pile foundation and the new subway, the distance relationship between the dynamic stress field of soft soil and the subway is established as: d =f(D)=a4·D+b4, where a4 and b4 are fitting parameters.

5. The safety risk assessment method for selecting a new urban subway line according to claim 1 is characterized in that: The safe distance value range between the pile foundation of the existing building and the subway is obtained by integrating the pile foundation loss allowable model, the mechanical response model and the distance relationship model, including: Combined with the formula σ d =f(D) and dynamic stress field σ d The value range of D is determined, and based on the value range of D, the high-risk areas are marked with the pile foundation of the existing building as the base point, which provides a reference for the selection of new subway lines in the city.

6. A safety risk assessment system for new urban subway line selection, characterized in that: include: A data acquisition module, which is used to obtain the design subway parameter information and the stratum information and existing building information along the proposed subway line; A pile foundation loss construction module, which is used to establish an allowable model for pile foundation losses of existing buildings based on the existing building information and the stratum information along the proposed subway line; A mechanical response building module, which is used to build a dynamic and static mechanical response model of soft soil according to the stratum information along the proposed subway line; A distance relationship building module, which is used to establish a distance relationship model between the dynamic stress field generated by subway operation and the subway through numerical simulation according to the designed subway parameter information and the stratum information along the proposed subway line; The safety assessment module is used to integrate the pile foundation loss allowable model, mechanical response model and distance relationship model to obtain the safe distance value range between the pile foundation of the existing building and the subway, and evaluate the safety of the line selection of the new subway.

7. A computer evaluation device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it can be used to perform the method described in any one of claims 1 to 5, or to run the system described in claim 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it can be used to perform the method described in any one of claims 1 to 5, or to run the system described in claim 6.

Images