A soil pressure calculation method and system for circular foundation pit support structure

Abstract

The present invention discloses a soil pressure calculation method and system for a circular foundation pit support structure, comprising: establishing a numerical analysis model of the circular foundation pit support structure; obtaining a deformation curve and a hoop stress coefficient of a circular ground-connected wall through the numerical analysis model; obtaining a calculation formula for the horizontal soil pressure of the circular ground-connected wall under a limit state according to a horizontal layering method combined with a force balance formula, a moment balance formula, and a hoop stress coefficient fitting formula; correcting the internal friction angle of the soil by considering the influence of displacement to obtain a soil cohesion value and a wall-soil cohesion value under a non-limit state; calculating the horizontal soil pressure of the circular ground-connected wall under a non-limit state according to the two cohesion values ​​and the calculation formula for the horizontal soil pressure of the circular ground-connected wall under a limit state; and providing a measurement index and a reference basis for the optimized design size of the circular foundation pit support structure by simultaneously considering the lateral deformation of the wall and the influence of the hoop stress of the circular foundation pit.

Description

Technical Field

[0001] The present invention belongs to the technical field of ground-connected wall foundation pit enclosure, and more specifically, relates to a soil pressure calculation method and system for a circular foundation pit support structure. Background Art

[0002] During the design of circular foundation pit support structures, differences in the surrounding environment and engineering geological conditions primarily influence the design dimensions of the support structure through differences in the horizontal earth pressure acting on it. Therefore, to determine the rationality of the design dimensions of underground diaphragm wall support structures, it is necessary to analyze the magnitude and distribution of the horizontal earth pressure acting on them. Current specifications for foundation pit support engineering generally recommend the Coulomb active earth pressure theory and the Rankine earth pressure theory for calculating earth pressure. When the retaining structure has high stiffness and the overall lateral deformation of the structure is small, the static earth pressure theory is recommended for calculating the earth pressure of the support structure. In the actual calculation and simulation of earth pressure on circular support structures, we found a significant discrepancy between the numerical simulation results and the theoretical calculations. The methods provided in the specifications do not account for the influence of lateral wall deformation on the earth pressure borne by the wall. Due to the arching effect, the lateral deformation of the wall in circular foundation pits is smaller than that in strip foundation pits. This makes it difficult for the soil behind the wall to reach the limit equilibrium state assumed in the theoretical calculations, which in turn affects the magnitude of the horizontal earth pressure. Consequently, the calculated earth pressure values ​​differ from the numerical results.

[0003] Therefore, there is an urgent need for a soil pressure calculation method that can simultaneously consider the influence of the lateral deformation of the wall and the annular stress of the circular foundation pit. Summary of the Invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a soil pressure calculation method and system for a circular foundation pit support structure, which simultaneously considers the influence of the lateral deformation of the wall and the circumferential stress of the circular foundation pit. It can solve the problem that the current calculation of the soil pressure of a circular foundation pit does not take into account the influence of the lateral deformation of the wall and the circumferential stress of the circular foundation pit, resulting in large errors in the calculation results of the horizontal soil pressure borne by the circular foundation pit support structure. It provides measurement indicators and reference basis for the optimized design size of the circular foundation pit support structure, and provides technical support for the promotion and application of the circular foundation pit structure.

[0005] To achieve the above object, one aspect of the present invention provides a method for calculating the earth pressure of a circular foundation pit support structure, comprising the following steps:

[0006] S1: A numerical analysis model of the circular foundation pit support structure is established based on the circular foundation pit structure and surrounding soil data;

[0007] S2: numerically simulating the circular foundation pit support structure using the numerical analysis model of the circular foundation pit support structure to obtain a deformation curve and a hoop stress coefficient of the circular ground-connected wall;

[0008] S3: According to the variation law of the hoop stress of the circular ground-connected wall with the ratio of the wall height to the excavation depth when the foundation pit is excavated to the bottom, the hoop stress coefficient fitting formula is obtained;

[0009] S4: Divide the sliding soil behind the circular diaphragm wall into several layers vertically, and obtain the calculation formula for the horizontal earth pressure of the circular diaphragm wall under the limit state based on the horizontal layering method combined with the force balance formula, moment balance formula and hoop stress coefficient fitting formula of the circular diaphragm wall;

[0010] S5: by considering the influence of displacement, the soil internal friction angle in the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state is corrected to obtain the soil cohesion value and the wall-soil cohesion value under the non-limit state;

[0011] S6: Calculate the horizontal earth pressure of the circular ground-connected wall under the non-limit state according to the soil cohesion value, the wall-soil cohesion value and the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state.

[0012] Furthermore, the hoop stress coefficient fitting formula in step S3 is expressed by equations (1) to (3):

[0013]

[0014]

[0015]

[0016] Where λ is the hoop stress coefficient of the circular ground-connected wall; D is the diameter of the foundation pit, H0 is the excavation depth when the foundation pit is excavated to the bottom, H is the wall height, and λ 1.0 ,λ 0.77 ,λ 0.19 ,λ 0.0 They are the hoop stress coefficients at H / H0 of 1.0, 0.77, 0.19 and 0.0 respectively.

[0017] Furthermore, the force balance formula of the circular ground-connected wall in step S4 includes a horizontal force balance equation and a vertical force balance equation;

[0018] The force balance equation of the upper part of the wall obtained according to the Mohr-Coulomb failure criterion is expressed by formula (13):

[0019]

[0020] The force balance equation of the lower part of the wall obtained according to the Mohr-Coulomb failure criterion is expressed by formula (14):

[0021]

[0022] Where dy is the thickness of the sliding soil behind the wall divided into several layers vertically; P a The wall is subjected to the wall side reaction force in the horizontal direction, that is, the soil pressure; P c is the extrusion pressure generated by circumferential extrusion; T is the inter-strip force of the upper soil layer; T+dT is the inter-strip force of the lower soil layer; R f is the force perpendicular to the sliding surface from the sliding surface; T f is the force parallel to the sliding surface; x is the horizontal length of the sliding soil behind the wall divided into several layers along the vertical direction; r is the inner curvature radius of the sliding soil behind the wall divided into several layers along the vertical direction; R is the outer curvature radius of the sliding soil behind the wall divided into several layers along the vertical direction; θ is the angle of the sliding surface;

[0023]

[0024] c2=c;c w =0.7c; is the internal friction angle of soil; is the corrected soil internal friction angle; P y is the load transferred from the upper soil layer; c is the soil cohesion; c w is the cohesion between the wall and soil; S is the lateral displacement of the wall,

[0025] Furthermore, the calculation formula for the horizontal earth pressure of the circular ground-connected wall under the limit state in step S4 is expressed by formula (16):

[0026]

[0027] Where δ is the friction angle between the wall and the soil; c2=c.

[0028] Furthermore, when the soil is in a non-limit state in step S4, the relationship between the wall displacement and the internal friction angle of the soil is:

[0029]

[0030] in, is the calculated internal friction angle; η is the coefficient considering the influence of wall displacement on the internal friction angle of soil; is the initial internal friction angle between the wall displacement and the soil, and is expressed by formula (24):

[0031]

[0032] Where K0 is the static side pressure coefficient.

[0033] Furthermore, when S≤S c hour, When S≥S c When η=1;

[0034] S is the lateral displacement of the wall; S c It is the lateral deformation of the wall when the limit state is reached.

[0035] Furthermore, the soil cohesion value under the non-limit state in step S5 is expressed by formula (25):

[0036]

[0037] The cohesion between the wall and soil under the non-limit state is expressed by formula (26):

[0038]

[0039] Among them, c m is the calculated soil cohesion value; c mw is the calculated value of the cohesion between the wall and soil.

[0040] A second aspect of the present invention provides an earth pressure calculation system for a circular foundation pit support structure, which is used to implement the earth pressure calculation method for the circular foundation pit support structure, comprising:

[0041] Numerical analysis model acquisition module, used to establish a numerical analysis model of the circular foundation pit support structure based on the circular foundation pit structure and surrounding soil data;

[0042] A deformation curve and hoop stress coefficient acquisition module is used to perform numerical simulation on the circular foundation pit support structure using the numerical analysis model of the circular foundation pit support structure to obtain the deformation curve and hoop stress coefficient of the circular ground-connected wall;

[0043] The hoop stress coefficient fitting formula acquisition module is used to obtain the hoop stress coefficient fitting formula based on the variation law of the hoop stress of the circular ground-connected wall with the ratio of the wall height to the excavation depth when the foundation pit is excavated to the bottom;

[0044] The module for obtaining horizontal earth pressure under the limit state is used to divide the sliding soil behind the circular ground-diaphragm wall into several layers vertically. The calculation formula for the horizontal earth pressure of the circular ground-diaphragm wall under the limit state is obtained based on the horizontal layering method combined with the force balance formula, moment balance formula and hoop stress coefficient fitting formula of the circular ground-diaphragm wall.

[0045] A module for obtaining the soil cohesion exertion value and the wall-soil cohesion exertion value under a non-limit state, which is used to correct the soil internal friction angle in the calculation formula for the horizontal earth pressure of the circular ground-connected wall under the limit state by considering the influence of displacement, and obtain the soil cohesion exertion value and the wall-soil cohesion exertion value under the non-limit state;

[0046] The horizontal earth pressure acquisition module under the non-limit state is used to calculate the horizontal earth pressure of the circular ground-connected wall under the non-limit state based on the soil cohesion value, the wall-soil cohesion value and the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state.

[0047] A third aspect of the present invention provides an electronic device, comprising a processor and a memory, wherein the processor and the memory are connected to each other;

[0048] The memory is used to store computer programs;

[0049] The processor is configured to execute the soil pressure calculation method of the circular foundation pit support structure when calling the computer program.

[0050] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, wherein the computer program is executed by a processor to implement the soil pressure calculation method of the circular foundation pit support structure.

[0051] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0052] The present invention provides a method for calculating the earth pressure of a circular foundation pit support structure. According to the circular foundation pit structure and the surrounding soil data, a numerical analysis model is established; numerical simulation is performed through the model to obtain the deformation curve and hoop stress coefficient of the ground-connected wall; a fitting formula is obtained by analyzing the variation law of the hoop stress with the ratio of the wall height to the excavation depth; the sliding soil behind the wall is vertically layered, and the force balance formula, the moment balance formula and the hoop stress coefficient fitting formula are combined to obtain the earth pressure calculation formula under the limit state; considering the influence of displacement, the friction angle in the soil body is corrected to obtain the soil cohesion value and the cohesion value between the wall and the soil under the non-limit state, and then the earth pressure under the non-limit state is calculated; the present invention can simultaneously consider the lateral deformation of the wall and The hoop stress of a circular foundation pit affects the design of a circular foundation pit support structure, thereby providing a more accurate soil pressure calculation result for the design of a circular foundation pit support structure; it can solve the problem that the current calculation of the soil pressure of a circular foundation pit does not take into account the lateral deformation of the wall and the influence of the hoop stress of the circular foundation pit, resulting in a large error in the calculation result of the horizontal soil pressure borne by the circular foundation pit support structure; this method of comprehensively considering multiple influencing factors can more accurately predict the stress conditions of the foundation pit in the actual environment, thereby providing more reliable data support for the design; accurate soil pressure calculation results provide an important measurement index and reference basis for the optimization design of the circular foundation pit support structure; designers can adjust and optimize the size of the support structure based on these data to achieve a design solution that is both safe and economical. Through the present invention, the behavior of circular foundation pits under different geological and environmental conditions can be better understood and predicted, thereby promoting its application in more engineering projects; accurate soil pressure calculation helps to ensure the safety of the foundation pit support structure, reduce the risk of structural failure due to calculation errors, and thus improve the safety of the project; the soil pressure calculation method of the circular foundation pit support structure of the present invention has shown significant beneficial effects in improving calculation accuracy, optimizing design, technical support, economic benefits, safety improvement, considering complex environmental factors, and engineering application verification. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a flow chart of a method for calculating earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0054] Figure 2 A schematic diagram of a circular foundation pit structure model for a method for calculating earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0055] Figure 3 A deformation curve diagram of a circular foundation pit diaphragm wall in a method for calculating earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0056] Figure 4 A diagram showing the distribution of the hoop force coefficient of the sliding soil mass along the height in a method for calculating the earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0057] Figure 5 This is a distribution diagram of hoop force coefficients under different internal friction angles in a method for calculating earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0058] Figure 6 This is a distribution diagram of hoop force coefficients under different foundation pit diameters according to a method for calculating earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0059] Figure 7 A schematic diagram of the force analysis of the upper part of the wall of a method for calculating the earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0060] Figure 8 A schematic diagram of the force analysis of the lower part of the wall of a method for calculating the earth pressure of a circular foundation pit support structure according to an embodiment of the present invention;

[0061] Figure 9 This is a schematic structural diagram of a soil pressure calculation system for a circular foundation pit support structure according to an embodiment of the present invention;

[0062] Figure 10 The figure is a schematic structural diagram of an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0063] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0064] like Figure 1 As shown, one aspect of the present invention provides a method for calculating the earth pressure of a circular foundation pit support structure, comprising the following steps:

[0065] S1: According to the circular foundation pit structure and the surrounding soil data, a numerical analysis model of the circular foundation pit support structure is established (such as Figure 2 shown);

[0066] S2: The circular foundation pit support structure is numerically simulated by the numerical analysis model of the circular foundation pit support structure to obtain the deformation curve and hoop stress coefficient of the circular ground-connected wall (such as Figure 3 and Figure 4 shown);

[0067] S3: According to the variation law of the hoop stress of circular diaphragm wall with the ratio of wall height to excavation depth when the foundation pit is excavated to the bottom (such as Figure 5 and Figure 6As shown), the fitting formula of hoop stress coefficient is obtained;

[0068] S4: Divide the sliding soil behind the circular diaphragm wall into several layers vertically, and obtain the calculation formula for the horizontal earth pressure of the circular diaphragm wall under the limit state based on the horizontal layering method combined with the force balance formula, moment balance formula and hoop stress coefficient fitting formula of the circular diaphragm wall;

[0069] S5: by considering the influence of displacement, the soil internal friction angle in the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state is corrected to obtain the soil cohesion value and the wall-soil cohesion value under the non-limit state;

[0070] S6: Calculate the horizontal earth pressure of the circular ground-connected wall under the non-limit state according to the soil cohesion value, the wall-soil cohesion value and the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state.

[0071] Furthermore, the hoop stress coefficient fitting formula in step S3 is expressed by equations (1) to (3):

[0072]

[0073]

[0074]

[0075] Where D is the diameter of the foundation pit, H0 is the excavation depth when the foundation pit is excavated to the bottom, H is the wall height, λ 1.0 ,λ 0.77 ,λ 0.19 ,λ 0.0 They are the hoop stress coefficients at H / H0 of 1.0, 0.77, 0.19 and 0.0 respectively.

[0076] Furthermore, the force balance formula of the circular ground-connected wall in step S4 includes a horizontal force balance equation and a vertical force balance equation; wherein, the layered force of the soil behind the wall is as follows: Figure 7 and Figure 8 As shown in the figure, we can see that: P a The wall is subjected to the wall side reaction force in the horizontal direction, which is the soil pressure, P c is the extrusion force generated by the circumferential extrusion; the horizontal force balance equation includes the force balance equation (4) of the upper part of the wall and the force balance equation (5) of the lower part of the wall;

[0077]

[0078]

[0079] Where dy is the thickness of the sliding soil behind the wall divided into several layers vertically; P a The wall is subjected to the wall side reaction force in the horizontal direction, that is, the soil pressure; P c is the extrusion pressure generated by circumferential extrusion; T is the inter-strip force of the upper soil layer; T+dT is the inter-strip force of the lower soil layer; R f is the force perpendicular to the sliding surface from the sliding surface; T f is the force parallel to the sliding surface; x is the horizontal length of the sliding soil behind the wall divided into several layers along the vertical direction; r is the inner curvature radius of the sliding soil behind the wall divided into several layers along the vertical direction; R is the outer curvature radius of the sliding soil behind the wall divided into several layers along the vertical direction; θ is the angle of the sliding surface;

[0080] According to the Mohr-Coulomb failure criterion:

[0081]

[0082]

[0083] T a =P a tanδ+c w (8)

[0084]

[0085] R=r+x (10)

[0086] x=(hy)cotθ (11)

[0087] P c =λP y (12)

[0088] Where c2 = c; c is the soil cohesion; c w is the cohesion between wall and soil; c w =0.7c; c w It is the cohesion between the wall and soil; is the internal friction angle of soil; is the corrected soil internal friction angle; c2=c;c w =0.7c;

[0089] According to the Mohr-Coulomb failure criterion, the simplified force balance equation of the upper part of the wall is obtained by simplifying Equation (4), which is expressed by Equation (13):

[0090]

[0091] According to the Mohr-Coulomb failure criterion, the simplified force balance equation of the lower part of the wall is obtained by simplifying Equation (5), which is expressed by Equation (14):

[0092]

[0093] Where S is the lateral displacement of the wall, which is expressed by the following formula:

[0094]

[0095] from Figure 7 and Figure 8 It can be seen that the soil layer is mainly subjected to the friction force between the wall and the soil T in the vertical direction. a , the weight of the sliding soil dW, the load transferred by the upper soil P y , the load P transferred from the underlying soil y +dP y and the force R perpendicular to the sliding surface from the sliding surface f , force T parallel to the sliding surface f , and unlike the horizontal force, the vertical force on the upper and lower soil layers of the wall is consistent, so the vertical force balance equation of the circular ground-connected wall can be expressed by formula (15):

[0096]

[0097] After simplifying formula (15), the calculation formula for the horizontal earth pressure of the circular ground-connected wall under the limit state is obtained, which is expressed by formula (16):

[0098]

[0099] Where δ is the friction angle between the wall and the soil;

[0100] By omitting the high-order differential terms in Equation (16), the vertical force equilibrium equation of the upper part of the circular ground-connected wall can be expressed by Equation (17):

[0101]

[0102] The vertical force equilibrium equation of the lower part of the wall is expressed by equation (18):

[0103]

[0104] Where A=B+tanδA1;

[0105] Furthermore, step S4 also includes a moment balance analysis of the center point of the horizontal layered soil wall. Since the arc of the ground-connected wall per unit length of the large-diameter foundation pit is small, the horizontal layered soil is regarded as a prism for the convenience of calculation. It can be seen that the moment balance formula of the circular ground-connected wall includes the moment balance formula (19) of the upper part of the wall and the moment balance formula (20) of the lower part of the wall:

[0106]

[0107]

[0108] Where, γ is the soil bulk density; Formula (19) and formula (20) are simplified as follows:

[0109]

[0110]

[0111] Furthermore, in step S4, the load P transferred by the upper soil layer of the circular ground-connected wall soil unit can be obtained by combining the boundary conditions. y The vertical distribution value of the load P can be transferred from the upper soil layer according to the calculation formula (16) of the horizontal earth pressure of the circular ground-connected wall under the limit state. y Calculate the earth pressure (the wall is subjected to the wall side reaction force in the horizontal direction) P a ; That is, the horizontal earth pressure of the circular diaphragm wall under the limit state is obtained.

[0112] Furthermore, the horizontal earth pressure of the circular ground-connected wall in step S4 is the earth pressure value when the sliding soil behind the wall is in the limit state. However, due to the large rigidity of the circular ground-connected wall structure, the displacement of the sliding soil is small, and the soil is in a non-limit state. When the soil is in the non-limit state, the relationship between the wall displacement and the internal friction angle of the soil is:

[0113]

[0114] in, is the calculated wall displacement and soil internal friction angle; η is the coefficient considering the influence of wall displacement on soil internal friction angle; is the initial internal friction angle between the wall displacement and the soil, and is expressed by formula (24): Wherein, K0 is the static side pressure coefficient;

[0115] When S≤S c hour,

[0116] When S≥S c When η=1;

[0117] Where S is the lateral displacement of the wall; S c is the lateral deformation of the wall when reaching the ultimate limit state;

[0118] According to the research of scholars, S c Regardless of the deformation mode of the wall and the density of the soil behind the wall, S cThe value is between 0.0003H and 0.0005H. Since the ground-connected wall has a "drum-shaped" deformation mode, a double-broken line approximation is used, that is, the lateral displacement S of the top and bottom of the wall is 0, while the middle of the wall is the maximum lateral deformation S m , thereby correcting the internal friction angle of soil and obtaining the soil cohesion value and the wall-soil cohesion value under non-limit state.

[0119] Furthermore, the soil cohesion value under the non-limit state in step S5 is expressed by formula (25):

[0120]

[0121] The cohesion between the wall and soil under the non-limit state is expressed by formula (26):

[0122]

[0123] Among them, c m is the calculated soil cohesion value; c mw is the calculated value of the wall-soil cohesion;

[0124] Furthermore, in step S6, the soil cohesion value obtained in step S5 under the non-limit state is substituted into the calculation formula (16) for the horizontal earth pressure of the circular ground-connected wall under the limit state, replacing the soil cohesion c and the wall-soil cohesion c w , the soil pressure distribution under non-limit state can be obtained.

[0125] The present invention provides a method for calculating the soil pressure of a circular foundation pit support structure, which takes into account the influence of the lateral deformation of the wall and the circumferential stress of the circular foundation pit. It can solve the problem that the current calculation of the soil pressure of a circular foundation pit does not take into account the influence of the lateral deformation of the wall and the circumferential stress of the circular foundation pit, resulting in large errors in the calculation results of the horizontal soil pressure borne by the circular foundation pit support structure. It provides measurement indicators and reference basis for the optimized design size of the circular foundation pit support structure, and provides technical support for the promotion and application of circular foundation pit structures.

[0126] like Figure 9 As shown, the second aspect of the present invention provides an earth pressure calculation system for a circular foundation pit support structure, which is used to implement the above-mentioned design method, including:

[0127] Numerical analysis model acquisition module, used to establish a numerical analysis model of the circular foundation pit support structure based on the circular foundation pit structure and surrounding soil data;

[0128] A deformation curve and hoop stress coefficient acquisition module is used to perform numerical simulation on the circular foundation pit support structure using the numerical analysis model of the circular foundation pit support structure to obtain the deformation curve and hoop stress coefficient of the circular ground-connected wall;

[0129] The hoop stress coefficient fitting formula acquisition module is used to obtain the hoop stress coefficient fitting formula based on the variation law of the hoop stress of the circular ground-connected wall with the ratio of the wall height to the excavation depth when the foundation pit is excavated to the bottom;

[0130] The module for obtaining horizontal earth pressure under the limit state is used to divide the sliding soil behind the circular ground-diaphragm wall into several layers vertically. The calculation formula for the horizontal earth pressure of the circular ground-diaphragm wall under the limit state is obtained based on the horizontal layering method combined with the force balance formula, moment balance formula and hoop stress coefficient fitting formula of the circular ground-diaphragm wall.

[0131] A module for obtaining the soil cohesion exertion value and the wall-soil cohesion exertion value under a non-limit state, which is used to correct the soil internal friction angle in the calculation formula for the horizontal earth pressure of the circular ground-connected wall under the limit state by considering the influence of displacement, and obtain the soil cohesion exertion value and the wall-soil cohesion exertion value under the non-limit state;

[0132] The horizontal earth pressure acquisition module under the non-limit state is used to calculate the horizontal earth pressure of the circular ground-connected wall under the non-limit state based on the soil cohesion value, the wall-soil cohesion value and the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state.

[0133] It should be noted that the soil pressure calculation system for the circular foundation pit support structure provided in this embodiment can be a computer program (including program code) running in a computer device. For example, the soil pressure calculation system for the circular foundation pit support structure is an application software; the soil pressure calculation system for the circular foundation pit support structure can be used to execute the corresponding steps in the above method provided in the embodiment of the present application.

[0134] In some feasible implementations, the soil pressure calculation system for the circular foundation pit support structure provided in this embodiment can be implemented by a combination of software and hardware. As an example, the soil pressure calculation system for the circular foundation pit support structure provided in this embodiment can be a processor in the form of a hardware decoding processor, which is programmed to execute the soil pressure calculation method for the circular foundation pit support structure provided in this embodiment. For example, the processor in the form of a hardware decoding processor can adopt one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs) or other electronic components.

[0135] In some feasible implementations, the soil pressure calculation system for the circular foundation pit support structure provided in this embodiment can be implemented in a software manner, which can be software in the form of programs and plug-ins, and include a series of modules to implement the soil pressure calculation method for the circular foundation pit support structure provided in the embodiment of the present invention.

[0136] The soil pressure calculation system for the circular foundation pit support structure provided in this embodiment solves the problem that the current calculation of the circular foundation pit soil pressure does not take into account the influence of the lateral deformation of the wall and the circumferential stress of the circular foundation pit, resulting in large errors in the calculation results of the horizontal soil pressure borne by the circular foundation pit support structure. It provides measurement indicators and reference basis for the optimized design size of the circular foundation pit support structure, and provides technical support for the promotion and application of circular foundation pit structures.

[0137] A third aspect of the present invention further provides an electronic device, Figure 10 Schematic diagram of the structure of the electronic device of this embodiment. Figure 10As shown, the electronic device 1000 in this embodiment may include: a processor 1001, a network interface 1004 and a memory 1005. In addition, the above-mentioned electronic device 1000 may also include: a user interface 1003, and at least one communication bus 1002. The communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), a keyboard (Keyboard), and the user interface 1003 may optionally include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a WI-FI interface). The memory 1004 may be a high-speed RAM memory, or a non-volatile memory (non-volatile memory), such as at least one disk memory. The memory 1005 may optionally be at least one storage device located away from the aforementioned processor 1001. As Figure 10 As shown, the memory 1005 as a computer-readable storage medium may include an operating system, a network communication module, a user interface module, and a device control application.

[0138] like Figure 10 In the electronic device 1000 shown, the network interface 1004 can provide network communication functions; the user interface 1003 is mainly used to provide an interface for user input; and the processor 1001 can be used to call the device control application stored in the memory 1005 to achieve:

[0139] A numerical analysis model of the circular foundation pit support structure is established based on the circular foundation pit structure and surrounding soil data;

[0140] The circular foundation pit support structure is numerically simulated by using the numerical analysis model of the circular foundation pit support structure to obtain the deformation curve and hoop stress coefficient of the circular ground-connected wall;

[0141] According to the variation law of the hoop stress of circular diaphragm wall with the ratio of wall height to excavation depth when the foundation pit is excavated to the bottom, the fitting formula of hoop stress coefficient is obtained.

[0142] The sliding soil behind the circular diaphragm wall is divided into several layers vertically. The calculation formula of the horizontal earth pressure of the circular diaphragm wall under the limit state is obtained by combining the force balance formula, moment balance formula and hoop stress coefficient fitting formula of the circular diaphragm wall according to the horizontal layering method.

[0143] By considering the influence of displacement, the soil internal friction angle in the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state is corrected to obtain the soil cohesion value and the wall-soil cohesion value under the non-limit state;

[0144] The horizontal earth pressure of the circular ground-connected wall under the non-limit state is calculated according to the soil cohesion value, the wall-soil cohesion value and the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state.

[0145] It should be understood that in some feasible embodiments, the processor 1001 may be a central processing unit (CPU). The processor may also be another general-purpose processor, a DSP, an ASIC, an FPGA, or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The general-purpose processor may be a microprocessor or any conventional processor. The memory may include a read-only memory and a random access memory, and provides instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store device type information.

[0146] In a specific implementation, the electronic device 1000 can execute the above-mentioned functions through its built-in functional modules. Figure 1 For the implementation methods provided in each step, please refer to the implementation methods provided in the above steps for details, which will not be repeated here.

[0147] The electronic device provided in this embodiment can solve the problem that the current calculation of circular foundation pit soil pressure does not take into account the influence of wall lateral deformation and circular foundation pit circumferential stress, resulting in large errors in the calculation results of the horizontal soil pressure borne by the circular foundation pit support structure, by simultaneously considering the influence of wall lateral deformation and circular foundation pit circumferential stress. It provides measurement indicators and reference basis for the optimized design size of the circular foundation pit support structure, and provides technical support for the promotion and application of circular foundation pit structures.

[0148] The present invention also provides a computer-readable storage medium that stores a computer program and is executed by a processor to implement Figure 1 For the methods provided in each step, please refer to the implementation methods provided in the above steps for details, which will not be repeated here.

[0149] The computer-readable storage medium provided in this embodiment can solve the problem that the current calculation of circular foundation pit soil pressure does not take into account the influence of wall lateral deformation and circular foundation pit hoop stress, resulting in large errors in the calculation results of the horizontal soil pressure borne by the circular foundation pit support structure. It provides measurement indicators and reference basis for the optimized design size of the circular foundation pit support structure, and provides technical support for the promotion and application of circular foundation pit structures.

[0150] Any reference to memory, storage, database or other media used in the various embodiments provided herein may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0151] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for calculating earth pressure of a circular foundation pit support structure, characterized in that: The steps include: S1: A numerical analysis model of the circular foundation pit support structure is established based on the circular foundation pit structure and surrounding soil data; S2: numerically simulating the circular foundation pit support structure using the numerical analysis model of the circular foundation pit support structure to obtain a deformation curve and a hoop stress coefficient of the circular ground-connected wall; S3: According to the variation law of the hoop stress of the circular ground-connected wall with the ratio of the wall height to the excavation depth when the foundation pit is excavated to the bottom, the hoop stress coefficient fitting formula is obtained; S4: Divide the sliding soil behind the circular diaphragm wall into several layers vertically, and obtain the calculation formula for the horizontal earth pressure of the circular diaphragm wall under the limit state based on the horizontal layering method combined with the force balance formula, moment balance formula and hoop stress coefficient fitting formula of the circular diaphragm wall; S5: by considering the influence of displacement, the soil internal friction angle in the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state is corrected to obtain the soil cohesion value and the wall-soil cohesion value under the non-limit state; S6: Calculating the horizontal earth pressure of the circular ground-connected wall under the non-limit state according to the soil cohesion value, the wall-soil cohesion value, and the calculation formula for the horizontal earth pressure of the circular ground-connected wall under the limit state; In step S4, the force balance formula of the circular ground-connected wall includes a horizontal force balance equation and a vertical force balance equation; the horizontal force balance equation includes a force balance equation for the upper part of the wall and a force balance equation for the lower part of the wall; The force balance equation of the upper part of the wall obtained according to the Mohr-Coulomb failure criterion is expressed by formula (13): The force balance equation of the lower part of the wall obtained according to the Mohr-Coulomb failure criterion is expressed by formula (14): Where dy is the thickness of the sliding soil behind the wall divided into several layers vertically; P a The wall is subjected to the wall side reaction force in the horizontal direction, i.e., the soil pressure; R f is the force perpendicular to the sliding surface from the sliding surface; x is the horizontal length of the sliding soil behind the wall divided into several layers along the vertical direction; r is the inner curvature radius of the sliding soil behind the wall divided into several layers along the vertical direction; R is the outer curvature radius of the sliding soil behind the wall divided into several layers along the vertical direction; θ is the angle between the sliding surfaces; λ is the hoop stress coefficient of the circular ground-connected wall; c2=c;c w =0.7c; is the internal friction angle of soil; is the corrected soil internal friction angle; P y is the load transferred from the upper soil layer; c is the soil cohesion; c w is the cohesion between the wall and soil; S is the lateral displacement of the wall, The calculation formula for the horizontal earth pressure of the circular ground-connected wall under the limit state in step S4 is expressed by formula (16): Where γ is the soil bulk density; δ is the friction angle between the wall and the soil; c2=c.

2. The soil pressure calculation method of a circular foundation pit support structure according to claim 1 is characterized by: The hoop stress coefficient fitting formula in step S3 is expressed by equations (1) to (3): Where λ is the hoop stress coefficient of the circular ground-connected wall; D is the diameter of the foundation pit, H0 is the excavation depth when the foundation pit is excavated to the bottom, H is the wall height, and λ 1.0 ,λ 0.77 ,λ 0.19 ,λ 0.0 They are the hoop stress coefficients at H / H0 of 1.0, 0.77, 0.19 and 0.0 respectively.

3. The soil pressure calculation method of a circular foundation pit support structure according to claim 1 is characterized by: When the soil is in a non-limit state in step S4, the relationship between the wall displacement and the internal friction angle of the soil is: in, is the calculated internal friction angle; η is the coefficient considering the influence of wall displacement on the internal friction angle of soil; is the initial internal friction angle between the wall displacement and the soil, and is expressed by formula (24): Where K0 is the static side pressure coefficient.

4. The soil pressure calculation method of a circular foundation pit support structure according to claim 3 is characterized by: When S≤S c hour, When S≥S c When η=1; S is the lateral displacement of the wall; S c It is the lateral deformation of the wall when the limit state is reached.

5. The soil pressure calculation method of a circular foundation pit support structure according to claim 4 is characterized in that: In step S5, the soil cohesion under the non-limit state is expressed by formula (25): The cohesion between the wall and soil under the non-limit state is expressed by formula (26): Among them, c m is the calculated soil cohesion value; c mw is the calculated value of the cohesion between the wall and soil.

6. A soil pressure calculation system for a circular foundation pit support structure, characterized in that: A method for calculating earth pressure of a circular foundation pit support structure according to any one of claims 1 to 5, comprising: Numerical analysis model acquisition module, used to establish a numerical analysis model of the circular foundation pit support structure based on the circular foundation pit structure and surrounding soil data; A deformation curve and hoop stress coefficient acquisition module is used to perform numerical simulation on the circular foundation pit support structure using the numerical analysis model of the circular foundation pit support structure to obtain the deformation curve and hoop stress coefficient of the circular ground-connected wall; The hoop stress coefficient fitting formula acquisition module is used to obtain the hoop stress coefficient fitting formula based on the variation law of the hoop stress of the circular ground-connected wall with the ratio of the wall height to the excavation depth when the foundation pit is excavated to the bottom; The module for obtaining horizontal earth pressure under the limit state is used to divide the sliding soil behind the circular ground-diaphragm wall into several layers vertically. The calculation formula for the horizontal earth pressure of the circular ground-diaphragm wall under the limit state is obtained based on the horizontal layering method combined with the force balance formula, moment balance formula and hoop stress coefficient fitting formula of the circular ground-diaphragm wall. A module for obtaining the soil cohesion exertion value and the wall-soil cohesion exertion value under a non-limit state, which is used to correct the soil internal friction angle in the calculation formula for the horizontal earth pressure of the circular ground-connected wall under the limit state by considering the influence of displacement, and obtain the soil cohesion exertion value and the wall-soil cohesion exertion value under the non-limit state; The horizontal earth pressure acquisition module under the non-limit state is used to calculate the horizontal earth pressure of the circular ground-connected wall under the non-limit state based on the soil cohesion value, the wall-soil cohesion value and the calculation formula of the horizontal earth pressure of the circular ground-connected wall under the limit state.

7. An electronic device, characterized in that: comprising a processor and a memory, wherein the processor and the memory are connected to each other; The memory is used to store computer programs; The processor is configured to execute the soil pressure calculation method for a circular foundation pit support structure according to any one of claims 1 to 5 when calling the computer program.

8. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the soil pressure calculation method of the circular foundation pit support structure according to any one of claims 1 to 5.

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