Analysis Method for Tunnel-Passing Frame Structures Based on Foundation Stress Loss

Abstract

This invention proposes an analysis method for tunnel-crossing frame structures based on foundation stress loss. This method addresses the potential damage to adjacent buildings caused by shield tunnels crossing existing surface structures. The aim is to simplify the damage analysis process, optimize damage assessment methods, clarify damage standards, and quantify damage levels, thereby achieving safe tunnel construction and ensuring the safety and usability of surface buildings after disturbance. The method includes the following steps: Step 1) Simplifying the building structure; Step 2) Calculating foundation settlement; Step 3) Calculating surface settlement; Step 4) Solving for internal forces in the building; Step 5) Comparing the building's resistance and stress. A structural safety factor η is used for rating, which is divided into four levels, each corresponding to different tasks.

Description

Technical Field

[0001] This invention relates to a method for analyzing surface building damage when foundation stress is lost due to disturbance of the strata during tunnel construction, using building damage assessment standards, and belongs to the field of geotechnical construction and tunnel engineering. Background Technology

[0002] Urban rail transit is of paramount importance as one of the most crucial and fundamental tasks in the process of modern urbanization. The development and utilization of urban underground transportation resources are gradually becoming the center and focus of urban transportation construction.

[0003] As an important component of urban infrastructure, tunnel construction is constantly increasing in both scale and number. During tunnel construction, the excavation work disrupts the structural balance of the original soil in the strata, causing deformation of the surrounding soil. This deformation may be transmitted to the foundation, causing uneven settlement of the foundation, and ultimately leading to cracking, tilting, or even damage to the superstructure.

[0004] With the increasing diversification of building functions and architectural styles, structural design has gained significant attention. Frame structure design, as a commonly used model, is widely applied in various types of buildings. Currently, the design of frame structures for multi-story buildings in my country is gradually integrating with advanced international concepts, and the systems and models of frame structures are showing a new trend of multi-channel development. The vertical shape and floor plan of buildings are becoming increasingly complex, bringing many new problems to those at risk of injury and placing higher demands on damage analysis of multi-story buildings. The use of frame structures in multi-story building design allows for large internal spaces and flexible floor plans. Due to the widespread application of frame structures in structural design, damage analysis of frame structure buildings is particularly important. However, some practical problems in the analysis of multi-story frame structures are often overlooked, leaving potential safety hazards for construction quality.

[0005] Therefore, further research and development of novel damage analysis technologies for tunnels passing under surface buildings are needed to improve work efficiency, reduce detection costs, and ensure the quality of analysis results. This can include optimizing building damage assessment methods, clarifying building damage standards, simplifying building damage analysis procedures, and quantifying building damage conditions.

[0006] In view of the above, this patent application is hereby filed. Summary of the Invention

[0007] The analysis method for tunnel side-passing frame structure buildings based on foundation stress loss described in this application aims to solve the problems existing in the prior art by proposing an analytical means to address the potential damage to adjacent buildings when shield tunnels pass side-passing existing surface buildings. The goal is to achieve safe tunnel construction and ensure the safety and usability of surface buildings after disturbance by simplifying the building damage analysis steps, optimizing the building damage identification method, clarifying the building damage standard, and quantifying the building damage situation.

[0008] To achieve the above design objectives, the analysis method for tunnel-crossing frame structures based on foundation stress loss includes the following implementation steps:

[0009] Step 1) Simplify the building structure;

[0010] Structural simplification of frame structures includes simplification of members, supports and joints, as well as load simplification;

[0011] Step 2) Calculate the settlement of the building foundation;

[0012] The settlement state of the building foundation is calculated using the layered summation method. During the calculation, due to the stress loss of the foundation caused by tunnel excavation and the reduced support of the surface soil on the foundation, a correction factor α is introduced into the foundation settlement calculation formula.

[0013] After adding the correction factor α, the foundation settlement after the loss of ground stress is obtained. ,Right now ;

[0014] The value of α is derived from the stress loss effect of the foundation caused by the external disturbance of the shield tunnel under the conditions of normal foundation settlement formula application, and the value is [value missing]. , For the ground loss rate during shield tunnel excavation, then ;

[0015] Step 3) Calculation of surface subsidence;

[0016] The surface settlement line is calculated using the surface settlement formula for shield tunnels. The maximum surface settlement S'_max and the width of the surface settlement trough i are corrected by introducing correction coefficients β and γ.

[0017] Step 4) Solving for the internal forces of the building;

[0018] Internal force analysis of ground-frame structures under displacement or deformation conditions;

[0019] Solve the internal forces of the building, including the axial force, shear force and bending moment of the structure, and only consider the main load-bearing structure to ensure the safety of the structure;

[0020] Let the maximum deformation be the vertical settlement S. Since the frame structure is a rigid structure when it is built, the vertical settlement S includes the settlement at any point on the ground surface after the loss of foundation stress. and foundation settlement after ground stress loss ,Right now Where x is the horizontal distance between the column on the side of the building closest to the tunnel and the centerline of the tunnel;

[0021] Step 5) Building resistance-stress comparison;

[0022] Based on the comparison between the detected and analyzed building stress and the building's own resistance, and in accordance with the prescribed standards, the building was treated accordingly.

[0023] The structural safety factor η is used for rating, and the rating is divided into four levels, with different levels corresponding to different jobs;

[0024] The safety factor η is used to analyze the degree of damage to buildings and to take reinforcement measures.

[0025] The formula for calculating the safety factor η is as follows: ;

[0026] In the formula, R represents structural resistance, which refers to the ability of a structure or structural component to resist external forces without failure, including bending resistance, shear resistance, and axial resistance.

[0027] γ0 is the importance coefficient of the structure, and it is set to 1.1 in the frame structure to improve stability analysis;

[0028] F represents the effect, referring to the structural internal forces caused by the vertical displacement resulting from the loss of foundation stress, including bending moment M, shear force Q, and axial force N, which are calculated using the displacement method equations mentioned above.

[0029] Step 1) simplifies the members, including simplifying beams and columns by replacing them with a single axis; simplifies the joints between beams and columns by simplifying them into rigid connections; and simplifies the loads, including concentrated forces, uniformly distributed loads, and bending moments.

[0030] The calculation formula for step 2) of the layered summation method is as follows:

[0031] (1)

[0032] In the formula, This refers to the basic settlement, in mm.

[0033] Based on the average self-weight stress of the i-th layer The corresponding porosity is obtained from the ep curve;

[0034] Based on the average self-weight stress of the i-th layer With the average value of additional stress The sum of these values ​​yields the corresponding porosity from the ep curve;

[0035] , , , respectively, are the compression coefficient, compression modulus, and volumetric compression coefficient of the i-th soil layer.

[0036] Step 3) First, calculate the settlement at any point on the ground according to the following Peck calculation. :

[0037] (2)

[0038] In the formula, The settlement at any point on the ground, in units of ;

[0039] This represents the maximum ground settlement, located at the center of symmetry of the settlement curve (corresponding to the tunnel axis position), in units of... ;

[0040] This is the distance from the center of the settlement curve to the point being calculated, in meters.

[0041] The distance from the center of symmetry of the settlement curve to the inflection point (reversal point) of the curve is generally called the "settlement trough width," and the unit is 1000 kilometres per second. ;

[0042] Then, a correction factor is introduced. γ is used to correct the maximum settlement and the width of the settlement channel to obtain an accurate calculation structure, resulting in the following formula:

[0043] (3)

[0044] in γ is the correction factor for maximum surface settlement, reflecting the changes in the maximum surface settlement value based on Peck's formula and local experience; γ is the correction factor for settlement trough width, reflecting the changes in the calculated value of settlement trough width based on Peck's formula and local experience.

[0045] Introduced coefficients , The calculation process is as follows:

[0046] First, a regression analysis is performed after taking the logarithm of the traditional Peck formula. The constant term after regression. The linear coefficients after regression are:

[0047] , ; (4)

[0048] Then, by selecting surface settlement monitoring data similar to those used in shield tunnel construction, regression simulation can be performed to obtain... The value is:

[0049] Combine the above formulas (3) and (4) to calculate The specific value.

[0050] Step 4), which involves calculating the internal forces of building settlement caused by foundation stress, includes the following steps:

[0051] 4.1) Determine the basic unknowns;

[0052] Add rigid arms to the nodes of the original structure that have angular displacement and linear displacement, respectively, to prevent rotation and support links to prevent movement. The sum of the number of additional rigid arms and additional support links is the basic unknown of the displacement method.

[0053] 4.2) Based on the condition that the sum of the constraint forces on the additional constraints is zero, establish the displacement method equations. (i,j=1,2,…,n);

[0054] 4.3) Draw the unit displacement of the building by each additional constraint. Bending moment diagram at =1 The bending moment diagram Mp under load is obtained, and the coefficient k is determined from the equilibrium conditions. ij and free item F ip ;

[0055] 4.4) Solving the equation ;

[0056] 4.5) Calculate the end moments of the members using the superposition principle. 1 + 2 n +M p The simplified internal forces of the frame structure were calculated.

[0057] Step 5), the rating content includes, when η≥1.00, it indicates that the building has not been damaged or the damage is extremely minor, and no reinforcement measures are required at this time;

[0058] When η≥0.95, it indicates that the building has been damaged, but the load-bearing capacity of the structure has not been significantly affected. At this time, it is not necessary to carry out reinforcement measures, but repair measures can be carried out for visual effect.

[0059] When η≥0.90, it indicates that the building has been damaged and its load-bearing capacity has been significantly affected. In this case, reinforcement measures should be taken.

[0060] When η < 0.90, it indicates that the building has suffered serious damage and that the load-bearing capacity of the structure has been severely affected. At this time, reinforcement measures must be taken in a timely manner.

[0061] In summary, the above-mentioned analysis method for tunnel-crossing frame structures based on foundation stress loss has the following advantages and beneficial effects:

[0062] 1. This application significantly solves the problems of long operation cycles, difficulty in controlling the construction period, and deviations in analysis results in traditional damage analysis of civil buildings. By optimizing the rating and procedures of damage analysis and improving the identification and treatment methods of damaged areas, it proposes a more reliable overall damage analysis procedure. This ensures the stability and reliability of the calculated damage analysis results for surface buildings when the foundation stress is lost due to disturbance of the strata during shield tunnel construction. All standards used are nationally unified standards, and the results have undergone rigorous testing and analysis to ensure accuracy meets requirements.

[0063] 2. This application can effectively simplify the operation process, improve the efficiency and quality of analysis work, and at the same time ensure the normal progress of underground construction and the safe use of surface buildings.

[0064] 3. This application proposes an optimized analysis process that can effectively reduce equipment costs and decrease manpower and resource consumption during construction.

[0065] 4. This application is applicable to the field of building damage assessment and has the potential to be extended to other underground construction projects, including but not limited to underground parking facilities and underground commercial centers, thus having broad application prospects and economic benefits, and is of great significance in the construction and renovation of subway tunnels. Attached Figure Description

[0066] The present application will now be further described in conjunction with the following figures;

[0067] Figure 1 A schematic diagram of an underground tunnel passing through a frame structure building;

[0068] Figure 2 A simplified diagram of the framework structure;

[0069] Figure 3 A schematic diagram of building settlement and deformation;

[0070] Figure 4 This is a schematic diagram of the overall structural deformation;

[0071] Figure 5-1 This is a schematic diagram of the stress on the building foundation before the shield tunnel is excavated;

[0072] Figure 5-2 This is a schematic diagram illustrating the impact of ground subsidence on the stress on building foundations.

[0073] Figure 6 A simplified diagram of the load;

[0074] Figure 7 A diagram showing the calculation of building settlement and deformation;

[0075] In the above figures, 1-Example of soil layer information; 2-Frame structure building; 3-Pile foundation; 4-Ground surface; 5-Tunnel construction location;

[0076] 11-Simplified beam and column members; 12-Simplified joints; 13-Simplified ground surface; Detailed Implementation

[0077] To further illustrate the technical means adopted by this application to achieve the intended design purpose, the following preferred embodiments are presented in conjunction with the accompanying drawings.

[0078] Specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0079] Example 1, such as Figures 1 to 7 As shown, the analysis method for tunnel side-passing frame structures based on foundation stress loss described in this application aims to clarify the damage standards of buildings and quantify the identification and analysis results.

[0080] The aforementioned frame structure refers to a building structure in which a frame composed of many beams and columns bears the entire load of the building. In existing high-rise residential buildings and multi-story industrial plants, brick walls are no longer sufficient to meet the requirements of heavy loads, and frames are often used as the load-bearing structure.

[0081] Whether a shield tunnel passes directly through a building or laterally through a building, it will cause ground subsidence. Once the ground subsidence exceeds the prescribed safety range, corresponding measures need to be taken immediately.

[0082] like Figure 3As shown, when a shield tunnel passes alongside a building, the surface tilting deformation is usually concentrated in the area above the cross-section and longitudinal section excavation face of the tunnel construction. This tilting is due to the soil losing its original support during tunnel excavation, causing the surrounding soil to move and redistribute, which in turn leads to uneven settlement of the ground surface.

[0083] When the ground tilts, the buildings above will also tilt. This tilt causes an eccentric effect on the building's own weight, resulting in an additional overturning moment in the building's structure. This moment can threaten the structural stability of the building, especially under external dynamic forces such as earthquakes or strong winds. Simultaneously, the building's load-bearing structure will also experience additional stress due to the ground tilt. These stresses may cause changes in the force transmission path within the building, leading to a redistribution of foundation reactions. This redistribution may result in excessive stress concentration in some areas, while potentially causing insufficient support in others.

[0084] During subway tunnel excavation, the ground may be disturbed. This disturbance not only affects the surrounding soil but may also alter the stress and strain field near the tunnel, leading to ground settlement. These changes may extend beneath the foundations of adjacent buildings, then transfer from the foundations to the substructure, and finally upwards to the structure, triggering secondary internal forces and deformations within the structure.

[0085] like Figure 5-1 As shown, when the shield tunnel is not under construction, the building is in a stable state, and the foundation stress is the reaction force generated by the gravity and loads exerted on the ground by the earth supporting the building.

[0086] like Figure 5-2 As shown, after surface settlement occurs during the construction of a shield tunnel, the strata that originally generated foundation stress lose their supporting function for the building, resulting in a loss of foundation stress. Uneven surface settlement causes parts of the building to be suspended in mid-air. Due to its own weight, the building will undergo subsidence and deformation, eventually reaching stress equilibrium again.

[0087] To enable damage calculation of frame structures based on foundation stress loss during tunnel side-passing construction, the analysis method described in this application includes the following implementation steps:

[0088] Step 1) Simplify the building structure;

[0089] Structural simplification of frame structures includes simplification of members, supports and joints, as well as load simplification;

[0090] Among them, the connection between the earth and the building foundation, and the connection between the building foundation and the building superstructure are set as rigid connections, so that the earth, the building foundation and the superstructure are connected as an integral structure in subsequent analysis and calculation, so as to facilitate analysis and calculation.

[0091] Specifically, considering that the system is usually subjected to spatially coordinated forces, for ease of analysis, directions with insignificant coupling are considered separately, simplifying it into a planar structure. Meanwhile, the main load-bearing components of the frame structure are beams and columns; therefore, an ideal calculation model is used to replace the actual structure, omitting the construction of precise solutions to problems that are unnecessary to know in engineering.

[0092] like Figure 1 and Figure 2 As shown, the compressive stiffness (EA), bending stiffness (EI), and shear stiffness (GA) of each component are obtained by investigating the drawings or by calculation.

[0093] The simplification of members includes the simplification of beams and columns. To ensure accuracy, it can only be used when the condition L / H > 8 is met (this standard is a simplification standard in structural mechanics, where L is the length of the member and H is the width of the member). After simplification, it is replaced by a single axis.

[0094] The simplification of nodes involves simplifying the connection between beams and columns. Since these connections need to withstand bending moments and forces in all directions within the frame structure, they are simplified into rigid connections.

[0095] like Figure 6 As shown, the simplification of loads includes the simplification of concentrated forces, uniformly distributed loads, and bending moments;

[0096] Step 2) Calculate the settlement of the building foundation;

[0097] This includes calculations of uneven settlement of surface structures before tunnel excavation;

[0098] The settlement state of the building foundation is calculated using the layered summation method. During the calculation, due to the stress loss of the foundation caused by tunnel excavation and the reduced support of the surface soil on the foundation, a correction factor α is introduced into the foundation settlement calculation formula.

[0099] The formula for calculating using the stratified summation method is as follows:

[0100] (1)

[0101] In the formula, This refers to the basic settlement, in mm.

[0102] Based on the average self-weight stress of the i-th layer The corresponding porosity is obtained from the ep curve;

[0103] Based on the average self-weight stress of the i-th layer With the average value of additional stress The sum of these values ​​yields the corresponding porosity from the ep curve;

[0104] , , , respectively, are the compression coefficient, compression modulus and volumetric compression coefficient of the i-th soil layer;

[0105] After adding the correction factor α, the foundation settlement after stress loss is obtained. ,Right now ;

[0106] The value of α is derived from the stress loss effect of the foundation caused by the external disturbance of the shield tunnel under the conditions of normal foundation settlement formula application, and the value is [value missing]. , For the ground loss rate during shield tunnel excavation, ;

[0107] Ground settlement is fundamentally caused by ground loss due to tunnel boring machine (TBM) construction and the disturbance, remodeling, and reconsolidation of the surrounding soil due to shear failure. The ground loss rate, also known as the ground damage rate or ground erosion rate, is a crucial indicator of soil settlement, ground slippage, and ground loss during TBM construction. It is the ratio of the sum of the areas of ground with deformation characteristics such as ground slippage to the total ground area. The ground loss rate is an important parameter characterizing changes in the geological background, a key indicator for evaluating geological hazards, and a crucial indicator for assessing geological complexity and resource availability. Incorporating the ground loss rate into the calculation of building foundation settlement allows for accurate consideration of the impact of TBM construction. Since the foundation of a frame structure is simplified to a rigid connection with the superstructure, foundation settlement is included in the overall building settlement, and this calculation result will be used in subsequent calculations of the overall building settlement.

[0108] Step 3) Calculation of surface subsidence;

[0109] The surface settlement line is calculated using the surface settlement formula for shield tunnels. The maximum surface settlement S_max and the width i of the surface settlement trough are corrected by introducing correction coefficients β and γ, thereby improving the calculation accuracy for specific working conditions.

[0110] First, calculate the settlement at any point on the ground according to the following Peck formula:

[0111] (2)

[0112] In the formula, The settlement at any point on the ground, in units of ;

[0113] This represents the maximum ground settlement, located at the center of symmetry of the settlement curve (corresponding to the tunnel axis position), in units of... ;

[0114] This is the distance from the center of the settlement curve to the point being calculated, in meters.

[0115] The distance from the center of symmetry of the settlement curve to the inflection point (reversal point) of the curve is generally called the "settlement trough width," and the unit is 1000 kilometres per second. ;

[0116] Introducing coefficients , To obtain an accurate calculation structure, the maximum settlement and the width of the settlement trough were corrected, resulting in the following formula:

[0117] (3)

[0118] The following are the coefficients. , The calculation process:

[0119] First, a regression analysis is performed after taking the logarithm of the traditional Peck formula. The constant term after regression. The linear coefficients after regression are:

[0120] , ; (4)

[0121] By selecting surface settlement monitoring data with geological conditions similar to those of shield tunnel construction, regression simulation can be performed to obtain... The value is:

[0122] Combine the above formulas (3) and (4) to calculate The specific value;

[0123] Step 4) Solving for the internal forces of the building;

[0124] Internal force analysis of ground-frame structures under displacement or deformation conditions;

[0125] Solve the internal forces of the building, including the axial force, shear force and bending moment of the structure, and only consider the main load-bearing structure to ensure the safety of the structure;

[0126] Specifically, since the tunnel's side passage causes the most severe deformation of the building's superstructure, the structure closest to the tunnel is assumed to be the maximum vertical settlement S.

[0127] Since frame structures are rigid structures during construction, the settlement S includes the settlement at any point on the ground surface after the loss of foundation stress. and foundation settlement after ground stress loss ,Right now Where x is the horizontal distance between the column on the side of the building closest to the tunnel and the centerline of the tunnel;

[0128] The calculation of internal forces for building settlement caused by foundation stress includes the following steps:

[0129] 4.1) Determine the basic unknowns;

[0130] Add rigid arms to the nodes of the original structure that have angular displacement and linear displacement, respectively, to prevent rotation and support links to prevent movement. The sum of the number of additional rigid arms and additional support links is the basic unknown of the displacement method.

[0131] 4.2) Based on the condition that the sum of the constraint forces on the additional constraints is zero, establish the displacement method equations. (i,j=1,2,…,n);

[0132] 4.3) Draw the unit displacement of the building by each additional constraint. Bending moment diagram at =1 The bending moment diagram Mp under load is obtained, and the coefficient k is determined from the equilibrium conditions. ij and free item F ip ;

[0133] 4.4) Solving the equation ;

[0134] 4.5) Calculate the end moments of the members using the superposition principle. 1 + 2 n +M p To calculate the simplified internal forces of the frame structure;

[0135] Step 5) Building resistance-stress comparison;

[0136] Based on the comparison between the detected and analyzed building stress and the building's own resistance, and in accordance with the prescribed standards, the building was treated accordingly.

[0137] The structural safety factor η is used for rating, and the system is divided into four levels, with different levels corresponding to different jobs.

[0138] The safety factor η is used to analyze the degree of damage to the building and to take reinforcement measures.

[0139] The formula for calculating the safety factor η is as follows: ;

[0140] In the formula, R represents structural resistance, which refers to the ability of a structure or structural component to resist external forces without failure, including bending resistance, shear resistance, and axial resistance.

[0141] γ0 is the importance coefficient of the structure, and it is set to 1.1 in the frame structure to improve stability analysis;

[0142] F represents the effect, referring to the structural internal forces caused by the vertical displacement resulting from the loss of foundation stress, including bending moment M, shear force Q, and axial force N, which are calculated from step 4) above.

[0143] The rating includes the following: when η≥1.00, it indicates that the building has not been damaged or the damage is extremely minor, and no reinforcement measures are required.

[0144] When η≥0.95, it indicates that the building has been damaged, but the load-bearing capacity of the structure has not been significantly affected. At this time, it is not necessary to carry out reinforcement measures, but repair measures can be carried out for visual effect.

[0145] When η≥0.90, it indicates that the building has been damaged and its load-bearing capacity has been significantly affected. In this case, reinforcement measures should be taken.

[0146] When η < 0.90, it indicates that the building has suffered serious damage and that the load-bearing capacity of the structure has been severely affected. At this time, reinforcement measures must be taken in a timely manner.

[0147] As described above, similar technical solutions can be derived from the solutions presented in conjunction with the accompanying drawings and description. Any solutions that do not depart from the structure of this invention still fall within the scope of the claims of this application.

Claims

1. A tunnel side-penetration frame structure building analysis method based on ground stress loss, characterized by: The implementation steps include the following, Step 1), building structure simplification; The building structure is simplified, including the simplification of the rod, support and joint, and the simplification of the load; Step 2), building foundation settlement calculation; The building foundation settlement state is calculated, and the layered summation method is used for calculation. The calculation considers the stress loss of the foundation caused by the tunnel excavation, the decrease of the support of the surface soil on the foundation, and the introduction of a correction coefficient α into the foundation settlement calculation formula; After adding the correction coefficient a, the foundation settlement amount after the stress loss of the foundation is obtained That is ; Wherein, the value of a is derived from the stress loss effect of the ground caused by the shield tunnel disturbance under the condition of using the normal foundation settlement formula, and the value is , is the stratum loss rate of the shield tunnel excavation, and ; is the foundation settlement, and the unit is mm; Step 3), ground surface settlement calculation; The ground surface settlement formula of shield tunnel is used to calculate the ground surface settlement line, and the maximum ground surface settlement and the ground surface settlement groove width i are corrected, the correction coefficients β and γ are introduced, and the calculation formula is as follows: （3） wherein is the maximum ground settlement correction coefficient, which reflects the change of the maximum ground settlement value based on the Peck formula and combined with local experience; γ is the settlement tank width correction coefficient, which reflects the change of the settlement tank width calculation value based on the Peck formula and combined with local experience; is the distance from the center of the settlement curve to the calculated point, with the unit of m; is the distance from the center of symmetry of the settlement curve to the inflection point of the curve, which is called the settlement tank width, with the unit of ; Step 4), building internal force solution; The internal force of the ground surface frame structure building is analyzed under the displacement or deformation condition; The internal force of the building is solved, including the axial force, shear force and bending moment of the structure, only the main force structure is considered, and the safety of the structure is ensured; The maximum deformation is vertical settlement S. Since the frame structure building is a rigid structure when it is built, the vertical settlement S includes the settlement of any point on the ground surface after the stress loss of the foundation and the foundation settlement after the stress loss of the foundation , that is ; wherein x is the horizontal distance between the column on the side of the building close to the tunnel and the center line of the tunnel. Step 5), building resistance-stress comparison; The building stress detected and analyzed is compared with the building resistance, and the standard is processed according to the standard; The safety factor η is used for rating, which is divided into four levels, and different levels correspond to different work; The safety factor η is used to analyze the damage degree of the building and take reinforcement measures; The calculation formula of the safety factor η is ; In the formula, R is the structural resistance, which is the ability of the structure or structural component to resist external force without damage, including bending resistance, shear resistance and axial resistance; γ0 is the importance coefficient of the structure, which is taken as 1.1 in the frame structure to improve the stability analysis; F is the action effect, which is the vertical displacement caused by the internal force of the structure after the loss of the foundation stress, including bending moment M, shear force Q and axial force N, which is calculated by the displacement method equation.

2. The ground-based stress loss based tunnel side-penetrating framed structure building analysis method according to claim 1, characterized by: The step 1) for the simplification of the rod includes the simplification of the beam and column, and one axis is used to replace the simplified beam and column; the simplification of the joint is the simplification of the connection between the beam and the column, which is simplified into a rigid connection; the simplification of the load includes the simplification of the concentrated force, uniform load and bending moment.

3. The ground-based stress loss based tunnel side-penetrating framed structure building analysis method according to claim 1, characterized by: The step 2) is calculated by the layered summation method, and the calculation formula is as follows, （1） In the formula, is the base settlement in mm; average value of the self-weight stress according to the i-th layer The corresponding void ratio is obtained from the e-p curve; the average value of the self-weight stress according to the i-th layer the average value of the additional stress the sum of the average values of the self-weight stress and the additional stress, from the e-p curve, the corresponding void ratio is obtained; , , are the compression coefficient, compression modulus and volumetric compression coefficient of the i-th layer of soil, respectively.

4. The ground-based stress loss based tunnel side-penetrating framed structure building analysis method according to claim 1, characterized by: The step 3) is calculated by the layered summation method, and the calculation formula is as follows, First, the settlement of any point on the ground surface is calculated according to the following Peck : （2） In the formula, is the settlement of any point on the surface, in units of ; is the maximum value of the ground settlement, located on the symmetry center of the settlement curve, corresponding to the position of the tunnel axis, with the unit of ; Then, a correction coefficient is introduced γ corrects the maximum settlement and the width of the settlement tank to obtain accurate calculation structure.

5. The ground-based stress loss based tunnel side-penetrating framed structure building analysis method according to claim 4, characterized by: The correction coefficient , The calculation process is as follows: First, the traditional Peck formula is taken logarithm and regression analysis is made, is the constant term after regression, is the linear coefficient after regression, and the following is obtained: ， ； （4） Then, the surface subsidence monitoring data similar to the geological conditions of shield tunnel construction are selected to perform regression simulation to obtain the surface subsidence prediction value, i.e. The value, i.e. .

6. The ground-based stress loss based tunnel side-penetrating framed structure building analysis method according to claim 1, characterized by: The step 4) for the building settlement internal force calculation caused by the foundation stress includes the following steps, 4.1), determine the basic unknown quantity; The nodes with angular displacement and linear displacement of the original structure are respectively added with a rigid arm to prevent rotation and a support chain to prevent movement. The sum of the additional rigid arm and the additional support chain is the basic unknown quantity of the displacement method; 4.2) The displacement method equation is established by the condition that the sum of the constraint forces on the additional constraints is zero where i, j = 1, 2,..., n; 4.3) Draw the bending moment diagram for the building under each additional constraint separately resulting in a unit displacement =1 and the bending moment diagram Mp under the load action, find the coefficient k from the equilibrium condition ij and the free term F ip ; 4.4), solving the equation ; 4.5) Calculate the end moment of the bar according to the superposition principle 1 + 2 n +M p to calculate the internal forces of the simplified frame structure.

7. The ground-based stress loss based tunnel side-penetrating framed structure building analysis method according to claim 1, characterized by: The step 5) includes the following rating contents, When η≥1.00, it indicates that the building has not been damaged or the damage is extremely insignificant, and no reinforcement measures are needed at this time; When η≥0.95, it indicates that the building has been damaged, but it has not significantly affected the carrying capacity of the structure, and no reinforcement measures can be selected at this time, but repair measures can be selected for visual effect; When η≥0.90, it indicates that the building has been damaged, and has significantly affected the carrying capacity of the structure, and reinforcement measures should be selected at this time; When η<0.90, it indicates that the building has been seriously damaged, and has seriously affected the carrying capacity of the structure, and reinforcement measures must be taken in time.

Images