CN113775349B - Method for determining propelling parameters of shield tunnel with small curvature radius - Google Patents

Abstract

The application provides a method for determining a propelling parameter of a shield tunnel with a small curvature radius, which comprises the following steps: determining the shield soil surrounding pressure when the shield tunneling machine is propelled based on a preset shield soil surrounding pressure model according to the friction coefficient between the shield tunneling machine and the soil body, the soil body floating volume weight of the shield tunneling machine with small curvature radius, the normal soil pressure coefficient of the shield tunneling machine and the equivalent volume weight of the shield tunneling machine when the shield tunneling machine with small curvature radius is propelled; determining shield head soil pressure when the shield machine is propelled according to a front soil pressure adjusting coefficient of the shield machine, a static soil pressure coefficient of the shield machine and a water pressure coefficient of the shield machine when the shield machine of the shield tunnel with small curvature radius is propelled and based on a preset shield head soil pressure model; determining the total thrust of a jack when the shield machine is propelled according to the soil pressure around the shield and the soil pressure at the shield head; and determining the torque of the shield tunneling machine during propulsion based on a preset propulsion torque model according to the soil body spring constant of the shield tunneling machine with small curvature radius and the turning angle of the shield tunneling machine which rotates once.

Description

A Method for Determining Propulsion Parameters of Shield Tunnel with Small Curvature Radius

technical field

The present application relates to the technical field of shield tunnel construction, in particular to a method for determining propulsion parameters of a shield tunnel with a small curvature radius.

Background technique

With the rapid development of society and economy, the continuous intensification of urbanization, the utilization of ground resources tends to be saturated, and the development and utilization of urban underground space resources has become one of the important directions of sustainable social development. Shield tunnel construction has become one of the main methods of underground tunnel construction such as subways because of its advantages of fast construction speed, safety and efficiency, and little interference to the urban ground environment. However, with the further development of urban underground space, due to the influence of deep foundation pits and underground pipelines, sometimes small radius curves appear in the design of subway axes, which puts forward higher requirements for shield construction control technology.

It is difficult to control the axis of a tunnel with a small radius of curvature. Since the shield machine itself is a linear rigid body, in order to make the tunnel axis fit the design axis, it is necessary to continuously rectify the deviation during the propulsion process to accurately control the attitude of the shield machine. The shield machine needs to adjust the propelling pressure of the shield to achieve curve turning and rectification. The smaller the radius of the tunnel axis, the lower the rectification sensitivity, and the more difficult the axis to control, which greatly increases the difficulty of axis control and rectification.

In actual projects, the distribution of the jack force system is usually adjusted based on construction experience, which increases the difficulty of construction and poses a great potential safety hazard. Therefore, it is necessary to provide an improved technical solution for the deficiencies of the above-mentioned prior art.

SUMMARY OF THE INVENTION

The purpose of the present application is to provide a method for determining the propulsion parameters of a shield tunnel with a small radius of curvature, so as to solve or alleviate the above-mentioned problems in the prior art.

In order to achieve the above purpose, the application provides the following technical solutions:

The present application provides a method for determining the propulsion parameters of a shield tunnel with a small curvature radius, including: step S1, according to the friction coefficient between the shield machine and the soil, the The soil floating bulk density of the shield tunnel with the small curvature radius, the normal earth pressure coefficient of the shield machine, and the equivalent bulk density of the shield machine are determined based on the preset earth pressure model around the shield to determine the small curvature The earth pressure around the shield when the shield machine is advancing in the radius shield tunnel; step S2, according to the front earth pressure adjustment coefficient of the shield machine when the shield machine with small curvature radius is advancing, the shield machine The static earth pressure coefficient and the water pressure coefficient of the shield machine are determined based on the preset shield head earth pressure model, and the shield head earth pressure when the shield machine with small curvature radius is pushed forward is determined; step S3, according to The earth pressure around the shield when the shield machine with small curvature radius is pushed forward and the earth pressure on the shield head when the shield machine with small curvature radius is pushed forward are used to determine the shield machine in shield tunnel with small curvature radius The total thrust of the jack during propulsion; Step S4, according to the soil spring constant of the shield tunnel with small curvature radius, the angle of rotation of the shield machine once, and based on a preset propulsion torque model, determine the small curvature Radius Shield Tunnel Torque when the shield machine is propelled.

Preferably, in step S1, based on a preset earth pressure model around the shield:

Calculate the earth pressure F _s around the shield when the shield machine of the shield tunnel with small curvature radius is advancing;

Among them, μ represents the friction coefficient between the shield tunnel with small curvature radius and the soil; L represents the total length of the shield tunnel; γ′ represents the soil bulk density of the shield tunnel with small curvature radius; K _θ represents the shield tunnel The normal _earth pressure coefficient of the The angle between any point on the cutter head of the machine and the horizontal plane.

Preferably, in step S1, according to the formula:

Calculate the normal earth pressure coefficient K _θ of the shield machine;

Among them, K _h is the horizontal earth pressure coefficient around the shield machine; K _v represents the vertical earth pressure coefficient around the shield machine.

Preferably, in step S2, based on a preset shield earth pressure model:

Calculate the shield head earth pressure F _head when the shield machine of the shield tunnel with small curvature radius is advancing;

为土体内摩擦角；γ′表示所述小曲率半径盾构隧道的土体浮容重；K_w表示盾构机的水压力系数；γ_w表示水容重；H表示所述小曲率半径盾构隧道的土层厚度。Among them, λ represents the frontal earth pressure adjustment coefficient of the shield machine; D represents the diameter of the cutter head of the shield machine; K ₀ represents the static earth pressure coefficient of the shield machine,

is the friction angle in the soil; γ′ represents the soil floating bulk density of the shield tunnel with small curvature radius; K _w represents the water pressure coefficient of the shield machine; γ _w represents the water bulk density; H represents the small curvature radius shield tunnel soil layer thickness.

Preferably, in step S2, in the sand and silt layers, the water pressure coefficient of the shield machine is K _w =1; in the cohesive soil layer, the water pressure coefficient of the shield machine is K _w =K ₀ .

Preferably, when the soil layer is cohesive soil, the value range of the frontal earth pressure adjustment coefficient λ of the shield machine is [1.05, 1.12].

Preferably, in step S3, the determination is made according to the earth pressure around the shield when the shield machine with the small curvature radius is advancing and the earth pressure at the shield head when the shield machine is advancing in the shield tunnel with the small curvature radius. The total thrust of the jack when the shield machine with small curvature radius is pushed forward is specifically: the earth pressure around the shield when the shield machine with small curvature radius is pushed forward and the shield of the small curvature radius shield tunnel The earth pressure of the shield head when the machine is pushed forward is calculated and calculated to determine the total thrust of the jack when the shield machine with small curvature radius is pushed forward.

Preferably, in step S4, based on a preset propulsion torque model:

Calculate the torque M when the shield tunneling machine with small curvature radius is propelled;

Among them, k represents the soil spring constant of the shield tunnel with small curvature radius; α represents the angle of rotation of the shield machine once; D represents the diameter of the cutter head of the shield machine; L _f represents the length of the front shield of the shield machine.

Preferably, in step S4, according to the formula:

Calculate the soil spring constant k of the shield tunnel with small curvature radius;

Among them, E _s is the soil elasticity model; E _p is the elasticity model of the shield machine; I _p is the inertia moment of the shield machine; v is the Poisson's ratio of the soil.

Preferably, the method for determining the propulsion parameters of the shield tunnel with small curvature radius further comprises: according to the total thrust of the jack when the shield tunnel with the small curvature radius is propelled and the torque when the shield machine is propelled, determine The shield machine rotates one rotation angle for thrust distribution.

Compared with the closest prior art, the technical solutions of the embodiments of the present application have the following beneficial effects:

The method for determining the propulsion parameters of a shield tunnel with a small curvature radius according to an embodiment of the present application comprehensively considers the influence of soil geological conditions and equipment structure on the shield machine, and quickly and accurately calculates the propulsion process of the shield machine in a shield tunnel with a small curvature radius The total thrust and torque of the jacks in the center provide a reliable basis for the trajectory planning and deviation correction of the shield tunnel with small curvature radius, which is beneficial to the thrust of the shield tunnel with small curvature radius during the construction process. Make precise assignments and real-time adjustments.

Description of drawings

The accompanying drawings that form a part of the present application are used to provide further understanding of the present application, and the schematic embodiments and descriptions of the present application are used to explain the present application and do not constitute improper limitations on the present application. in:

1 is a schematic flowchart of a method for determining propulsion parameters of a shield tunnel with a small curvature radius provided according to some embodiments of the present application;

FIG. 2 is the normal static earth pressure of the shield shell of the shield machine provided according to some embodiments of the present application;

3 is a schematic diagram of shield head pressure of a shield machine provided according to some embodiments of the present application;

4 is a schematic top view of the earth pressure increment around the shield of the curved section of the shield machine provided according to some embodiments of the present application;

FIG. 5 is a schematic top view of the earth pressure increment of the shield head in the curved section of the shield machine provided according to some embodiments of the present application;

6 is a schematic structural diagram of a system for determining propulsion parameters of a shield tunnel with a small curvature radius according to some embodiments of the present application.

Detailed ways

The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. The various examples are provided by way of explanation of the application and do not limit the application. In fact, it will be apparent to those skilled in the art that modifications and variations can be made in the present application without departing from the scope or spirit of the application. For example, features illustrated or described as part of one embodiment can be used on another embodiment to yield yet another embodiment. Therefore, it is intended that this application cover such modifications and variations as come within the scope of the appended claims and their equivalents.

In the description of this application, the terms "portrait", "horizontal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", " The orientations or positional relationships indicated by "top" and "bottom" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the application rather than requiring the application to be constructed and operated in a specific orientation, and therefore cannot be understood as LIMITATIONS ON THIS APPLICATION. The terms "connected", "connected" and "arranged" used in this application should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection; it may be directly connected or indirectly connected through intermediate components; for Those of ordinary skill in the art can understand the specific meanings of the above terms according to specific situations.

1 is a schematic flowchart of a method for determining propulsion parameters of a shield tunnel with a small curvature radius provided according to some embodiments of the present application; as shown in FIG. 1 , the method for determining propulsion parameters of a shield tunnel with a small curvature radius includes:

Step S1. According to the small curvature radius shield tunneling shield machine, the friction coefficient between the shield machine and the soil, the soil floating bulk density of the small curvature radius shield tunnel, the normal earth pressure coefficient of the shield machine, and the shield Based on the preset earth pressure model around the shield, determine the earth pressure around the shield when the shield machine is propelled with small curvature radius;

In the embodiment of the present application, the preset earth pressure model around the shield is shown in formula (1), and formula (1) is as follows:

Among them, F _s represents the earth pressure around the shield when the shield machine with small curvature radius is pushed forward, the unit is kilonewton (kN); μ represents the friction coefficient between the small curvature radius shield and the soil, dimensionless; L represents the shield The total length of the machine, in meters (m); γ′ represents the bulk density of the soil body of the shield tunnel with small curvature radius, in kN/m3 (kN/m ³ ); K _θ represents the method of the shield machine Earth pressure coefficient, dimensionless; D represents the diameter of the cutter head of the shield machine, in meters (m); H represents the thickness of the soil layer of the shield tunnel with small curvature radius, in meters (m); γ′ _ε represents the shield Equivalent bulk density of the machine, in kilonewtons per cubic meter (kN/m ³ ); θ represents the angle between any point on the cutter head of the shield machine and the horizontal plane.

In the embodiment of this application, the equivalent bulk density γ′ _ε of the shield machine is determined according to formula (2), and formula (2) is as follows:

Among them, w is the gravity of the shield machine and its ancillary equipment, and the unit is kilonewton (kN).

In the embodiment of this application, the normal earth pressure coefficient K _θ of the shield machine is determined according to (3), and the formula (3) is as follows:

Among them, K _h is the horizontal earth pressure coefficient around the shield machine; K _v is the vertical earth pressure coefficient around the shield machine.

In the embodiment of the present application, for the vertical earth pressure coefficient K _v , in the soft clay layer, it is defined that the earth pressure at the top of the tunnel is equal to the weight of the overlying soil column, that is, the vertical earth pressure is equal to the self-weight stress of the soil body, therefore, K _v = 1. For the horizontal earth pressure coefficient K _h , obtain through experiments or adopt K _h =K ₀ , where K ₀ is the static earth pressure coefficient (dimensionless).

In the embodiment of the present application, the static earth pressure coefficient K _h is determined according to the formula (4), and the formula (4) is as follows:

表示土体内摩擦角，单位为(rad)。在此，土体的内摩擦角通过对土体进行土工试验测得，在此，不再一一赘述。in,

Indicates the friction angle within the soil, in rad. Here, the internal friction angle of the soil is measured by performing a geotechnical test on the soil, which will not be repeated here.

盾构机底部受到的法向土压力为K_v(γ′_εH+γ′_εD)。In the embodiment of the application, the normal static earth pressure on the shield shell of the shield machine is shown in Figure 2. By integrating the normal earth pressure on the shield shell in the circumferential direction, the shield with small curvature radius can be obtained. Earth pressure F _s around the shield when the tunnel shield machine is advancing. Specifically, the normal earth pressure on the top of the shield machine is K _v γ′H; the normal earth pressure on the side of the shield machine is

The normal earth pressure on the bottom of the shield machine is K _v (γ′ _ε H+γ′ _ε D).

Step S2, according to the frontal earth pressure adjustment coefficient of the shield machine, the static earth pressure coefficient of the shield machine, and the water pressure coefficient of the shield machine when the shield machine is advancing with a small curvature radius, based on the preset shield head soil pressure. The pressure model determines the earth pressure of the shield head when the shield machine is pushed forward in a shield tunnel with a small curvature radius;

In the embodiment of the present application, the preset shield earth pressure model is shown in formula (5), and formula (5) is as follows:

为土体内摩擦角；γ′表示小曲率半径盾构隧道的土体浮容重，单位为千牛每立方米(kN/m³)；K_w表示盾构机的水压力系数，无量纲；γ_w表示水容重，单位为千牛每立方米(kN/m³)；H表示小曲率半径盾构隧道的土层厚度，单位为米(m)。Among them, F _head represents the shield head earth pressure when the shield machine is advancing in a shield tunnel with small curvature radius, the unit is kilonewton (kN); λ represents the frontal earth pressure adjustment coefficient of the shield machine, dimensionless; D represents the shield machine The diameter of the cutter head is in meters (m); K ₀ represents the static earth pressure coefficient of the shield machine, dimensionless,

is the friction angle in the soil; γ′ represents the floating bulk density of the shield tunnel with small curvature radius, the unit is kilonewton per cubic meter (kN/m ³ ); K _w represents the water pressure coefficient of the shield machine, dimensionless; γ _w represents the bulk density of water, in kilonewtons per cubic meter (kN/m ³ ); H represents the thickness of the soil layer of the shield tunnel with small curvature radius, in meters (m).

In the embodiment of the present application, for the water pressure coefficient K _w of the shield machine, in the sandy soil and silt stratum with good permeability, the water pressure coefficient of the shield machine is K _w =1; in the cohesive soil layer , the water pressure coefficient of the shield machine K _w =K ₀ . For the frontal earth pressure adjustment coefficient λ of the shield machine, it is usually determined according to the change of the nature of the soil after the disturbance, the propulsion speed of the shield machine and the overload condition of the shield machine. When the soil layer is cohesive soil, the shield machine The value range of the frontal earth pressure adjustment coefficient λ is [1.05, 1.12].

由刀盘中部受到的平均压力和刀盘面积，即可确定小曲率半径盾构隧道盾构机推进时的盾头土压力F_head。在此，需要说明是，设定地下水位线(地下水面)与土平面平行。In the embodiment of the present application, the pressure on the shield head of the shield machine is shown in Figure 3. Normally, the shield head (cutter head) of the shield machine is subjected to the combination of earth pressure (internal) and water pressure (external). It can be seen that the pressure on the top of the cutter head is: (K ₀ γ′H+K _w γ _w H); the pressure at the bottom of the cutter head is: K ₀ γ′(H+D)+K _w γ _w (H +D), so the average pressure in the middle of the cutter head is:

From the average pressure and the area of the cutter head in the middle of the cutter head, the earth pressure F _head of the shield head when the shield machine with small curvature radius is pushed forward can be determined. Here, it should be noted that the groundwater table (groundwater surface) is set to be parallel to the soil plane.

Step S3: According to the earth pressure around the shield when the shield machine is advancing in the shield tunnel with small curvature radius and the earth pressure at the shield head when the shield machine is advancing in the shield tunnel with small curvature radius, determine the time when the shield machine is advancing in the shield tunnel with small curvature radius. The total thrust of the jack;

In the embodiment of the present application, the earth pressure around the shield when the shield machine with small curvature radius is pushed forward and the earth pressure on the shield head when the shield machine with small curvature radius is pushed are summed to determine the shield with small curvature radius. The total thrust of the jack when the tunnel shield machine is propelled. Specifically, the total jack thrust F _jack when the shield machine is propelled is determined according to formula (6), and formula (6) is as follows:

F _jack =F _s +F _head ………………………………(6)

In the embodiment of the present application, during the propulsion process of the shield machine, the propulsion force is usually applied in blocks (by area, it can be divided into left driving force and right driving force), and the total thrust of the jack during propulsion is the left driving force. The sum of the force and the right driving force.

Step S4 , according to the soil spring constant of the shield tunnel with small curvature radius, the rotation angle of the shield machine once rotated, and based on the preset propulsion torque model, determine the torque of the shield tunnel with small curvature radius when the shield machine is propelled.

In the embodiment of the present application, the preset propulsion torque model is shown in formula (7), and formula (7) is as follows:

Among them, k represents the soil spring constant of the shield tunnel with small curvature radius, the unit is kilonewton per meter (kN/m); α represents the rotation angle of the shield machine once rotated, the unit is (rad); D represents the shield machine The diameter of the cutter head is in meters (m); L _f represents the length of the front shield of the shield machine, in meters (m).

In the embodiment of the present application, the soil spring constant k of the shield tunnel with small curvature radius is determined according to formula (8), and formula (8) is as follows:

Among them, E _s is the elastic modulus of the soil, the unit is kilopascal (kPa); E _p is the elastic modulus of the shield machine, the unit is kilopascal (kPa); I _p is the moment of inertia of the shield machine, the unit is Four square meters (m ⁴ ); v is the Poisson's ratio of the soil, dimensionless. Here, the elastic modulus of the shield machine is related to the material (steel) of the shield machine. Usually, the elastic modulus of the shield machine adopts the moment of inertia to the center of the circle.

In the embodiment of the present application, due to the rotation of the shield machine, the shield shell and the shield head will be pressed or moved away from the soil, thereby generating a moment on the rotation center (O ₁ ). Since the hinged position is in the middle of the shield machine, the shield machine is divided into a front shield (including the cutter head) and a back shield, and the part that the shield machine actually squeezes (or away from) the soil is mainly the front shield. Since the position where the jack of the shield machine is propelled is in the middle of the shield machine, and the rotation center (O ₁ ) of the shield machine is at the end of the front shield of the shield machine, the change in soil pressure around the front shield after rotation is shown in Figure 4.

As shown in Figure 4, the passive earth pressure increment generated by the front shield of the shield machine extruding the soil is Δσ _p ; the back shield of the shield machine is far away from the soil and the active earth pressure increment is Δσ _a , among which the passive earth pressure increment is Δσ a . The quantity Δσ _p and the active earth pressure increment Δσ _a change linearly on the shield shell. Taking the rotation center of the shield machine (O ₁ ) as the boundary, the force on the soil on both sides of the shield machine can be divided into an active area and a passive area. Here, when the shield machine rotates, the elastic modulus of the active area and the passive area is set Consistent, that is, the torque to the shield center (O ₁ ) is the same. The total torque M _shield generated by the shield shell load increment (active earth pressure increment and passive earth pressure increment) to O ₁ is shown in formula (9), and formula (9) is as follows:

Among them, L _f represents the length of the front shield of the shield machine, the unit is meters (m); α represents the rotation angle of the shield machine once rotated, the unit is (rad). The static earth pressure and water pressure on the shield head are symmetrical about the z-axis, so the moment on the z-axis is zero, and the stress increment after rotation produces a torque effect on the z-axis, as shown in Figure 5.

It can be seen from Figure 5 that the displacement of any point of the shield head (cutter head) satisfies the formula (10), and the formula (10) is as follows:

U=αρcosθ………………………………(10)

ρ is the distance from any point of the shield head to the center of the shield head, in meters (m). According to the symmetry, the stress increment of the shield head can also be divided into 4 parts according to the quadrant, and each part of the load increment produces the same moment on the z-axis. Therefore, the total torque M _head of the shield head earth pressure increment to the z-axis is shown in formula (11), and formula (11) is as follows:

From the total torque M _shield generated by the shield shell load increment to O ₁ and the total torque M _head of the shield head earth pressure increment to the z-axis, the torque of the shield tunnel with small curvature radius when the shield machine is propelled can be obtained. .

In the implementation of this application, in the shield tunnel with small curvature radius, the parameter values of shield propulsion resistance are shown in Table 1: Table 1

In some optional embodiments, the method for determining the propulsion parameters of a shield tunnel with a small curvature radius further includes: according to the total thrust of the jack when the shield tunnel with the small curvature radius is propelled and the torque during the propulsion of the shield The engine rotates one corner to distribute the thrust.

Specifically, according to the torque when the shield machine is propelling, it can be determined that when the shield machine rotates one rotation angle α, the moment difference between the left driving force and the right driving force is generated. Since the shield machine is propelling, the left driving force The moment arm of the right-hand drive force is the same and known, so the torque when propelled by the shield machine can determine the difference between the left-hand drive force and the right-hand drive force. Furthermore, combined with the total thrust of the jack (the sum of the left driving force and the right driving force) when the shield tunneling machine with small curvature radius is propelled, the left driving force and the right driving force when the shield machine is propelled can be determined. .

In the embodiment of the present application, the influence of soil geological conditions and equipment structure on the shield machine is comprehensively considered, and the total thrust and moment of the jack during the propulsion process of the shield machine in a shield tunnel with a small curvature radius are calculated quickly and accurately, which is the small curvature radius The trajectory planning and deviation correction of the shield tunnel shield machine provides a reliable basis, which is conducive to the accurate distribution and real-time adjustment of the thrust during the turning of the shield machine with small curvature radius during the construction process.

6 is a schematic structural diagram of a system for determining propulsion parameters of a shield tunnel with a small curvature radius provided according to some embodiments of the present application; as shown in FIG. 6 , the system for determining propulsion parameters of a shield tunnel with a small curvature radius includes: a shield surrounding soil Pressure unit, shield earth pressure unit, total thrust unit and torque unit;

Wherein, the earth pressure unit around the shield is configured according to the friction coefficient between the shield machine and the soil body and the floating bulk density of the soil body of the shield tunnel with small curvature radius when the shield machine with small curvature radius is advancing. , the normal earth pressure coefficient of the shield machine, the equivalent bulk density of the shield machine, and based on the preset earth pressure model around the shield, determine the shield circumference when the shield machine is advancing in the shield tunnel with small curvature radius earth pressure;

The shield head earth pressure unit is configured to adjust the frontal earth pressure coefficient of the shield machine, the static earth pressure coefficient of the shield machine, According to the water pressure coefficient of the machine, based on the preset shield earth pressure model, determine the shield earth pressure of the shield tunnel with small curvature radius when the shield machine is propelled;

The total thrust unit is configured to determine the small curvature according to the earth pressure around the shield when the shield machine with small curvature radius is advancing and the earth pressure on the shield head when the shield machine is advancing in the shield tunnel with small curvature radius The total thrust of the jack when the shield machine in the radius shield tunnel is propelled;

a torque unit, configured to determine the shield tunnel with small curvature radius based on a preset propulsion torque model according to the soil spring constant of the shield tunnel with small curvature radius, the rotation angle of the shield machine once rotated, and based on a preset propulsion torque model The torque when the shield machine is propelled.

The system for determining the propulsion parameters of a shield tunnel with a small curvature radius provided by the embodiment of the present application can realize the steps and processes of the method for determining the propulsion parameters of a shield tunnel with a small curvature radius described in any of the above embodiments, and achieve the same technical effect. I won't repeat them one by one.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims (10)

1. A method for determining the propelling parameters of a shield tunnel with small curvature radius is characterized by comprising the following steps:

step S1, determining shield circumferential soil pressure when the shield machine with small curvature radius is propelled based on a preset shield circumferential soil pressure model according to a friction coefficient of the shield machine and a soil body, a soil body floating volume weight of the shield tunnel with small curvature radius, a normal soil pressure coefficient of the shield machine and an equivalent volume weight of the shield machine when the shield machine with small curvature radius is propelled;

s2, determining shield head soil pressure when the shield machine with small curvature radius is propelled based on a preset shield head soil pressure model according to a front soil pressure adjusting coefficient of the shield machine, a static soil pressure coefficient of the shield machine and a water pressure coefficient of the shield machine when the shield machine with small curvature radius is propelled;

s3, determining the total thrust of a jack when the shield machine with the small curvature radius is propelled according to the soil pressure around the shield when the shield machine with the small curvature radius is propelled and the soil pressure at the shield head when the shield machine with the small curvature radius is propelled;

and S4, determining the torque of the shield machine with the small curvature radius during propulsion according to the soil body spring constant of the shield tunnel with the small curvature radius and the corner of the shield machine which rotates once based on a preset propulsion torque model.

2. The small curvature radius shield tunnel propulsion parameter determination method of claim 1, wherein, in step S1,

based on the preset soil pressure model around the shield:

calculating the shield surrounding soil pressure F when the shield tunneling machine with small curvature radius is propelled _s ；

Mu represents the friction coefficient of the shield with the small curvature radius and the soil body; l represents the total length of the shield machine; gamma' represents the floating volume weight of the soil body of the shield tunnel with the small curvature radius; k is _θ Representing the normal soil pressure coefficient of the shield machine; d represents the diameter of a cutter head of the shield tunneling machine; h represents the thickness of the soil layer of the shield tunnel with the small curvature radius; gamma's' _ε Representing the equivalent volume weight of the shield machine; and theta represents an included angle between any point on the cutter head of the shield tunneling machine and the horizontal plane.

3. The method for determining the propulsion parameters of the shield tunnel with the small curvature radius according to claim 2, wherein in step S1, according to the formula:

calculating normal soil pressure coefficient K of shield machine _θ ；

Wherein, K _h The pressure coefficient of the horizontal soil around the shield machine is obtained; k is _v And expressing the vertical soil pressure coefficient around the shield machine.

4. The small curvature radius shield tunnel propulsion parameter determination method of claim 1, wherein, in step S2,

based on the shield head soil pressure model that predetermines:

calculating shield head soil pressure F when the shield tunneling machine with small curvature radius is propelled _head ；

Wherein, lambda represents the front soil pressure adjustment coefficient of the shield machine; d represents the diameter of a cutter head of the shield tunneling machine; k is ₀ The static soil pressure coefficient of the shield machine is shown,

the internal friction angle of the soil body; gamma' represents the floating volume weight of the soil body of the shield tunnel with the small curvature radius; k is _w Representing the water pressure coefficient of the shield machine; gamma ray _w Represents the water volume weight; h represents the thickness of the soil layer of the shield tunnel with the small curvature radius.

5. The small curvature radius shield tunnel propulsion parameter determination method of claim 4, wherein, in step S2,

in sandy soil and silty soil stratum, the water pressure coefficient K of the shield machine _w ＝1；

In a cohesive soil layer, the water pressure coefficient K of the shield machine _w ＝K ₀ 。

6. The method for determining the propelling parameters of the shield tunnel with the small curvature radius according to claim 4, wherein when a soil layer is clayey soil, the value range of the front soil pressure adjustment coefficient lambda of the shield machine is [1.05,1.12].

7. The method for determining the propulsion parameters of the shield tunnel with the small curvature radius according to claim 1, wherein in step S3, the total jack thrust force when the shield tunnel with the small curvature radius is propelled is determined according to the shield earth pressure around the shield machine when the shield tunnel with the small curvature radius is propelled and the shield earth pressure when the shield tunnel with the small curvature radius is propelled, and specifically:

and performing sum operation on the soil pressure around the shield when the shield machine with the small curvature radius is propelled and the soil pressure at the shield head when the shield machine with the small curvature radius is propelled, and determining the total thrust of the jack when the shield machine with the small curvature radius is propelled.

8. The small curvature radius shield tunnel propulsion parameter determination method of claim 1, wherein, in step S4,

based on a preset propulsion torque model:

calculating the torque M when the shield tunneling machine with the small curvature radius advances;

wherein k represents the soil body spring constant of the shield tunnel with small curvature radius; alpha represents the rotation angle of the shield machine after one rotation; d represents the diameter of a cutter head of the shield tunneling machine; l is a radical of an alcohol _f Showing the anterior shield length of the shield machine.

9. The small radius of curvature shield tunnel propulsion parameter determination method of claim 8, wherein, in step S4,

according to the formula:

calculating a soil body spring constant k of the shield head tunnel with the small curvature radius;

wherein E is _s The elastic modulus of the soil body; e _p The elastic modulus of the shield machine; I.C. A _p The moment of inertia of the shield tunneling machine; v is the poisson's ratio of the soil mass.

10. The method for determining the advancing parameter of the shield tunnel with the small curvature radius according to any one of claims 1 to 9, wherein the method for determining the advancing parameter of the shield tunnel with the small curvature radius further comprises:

and distributing the thrust for the shield tunneling machine to rotate a primary corner according to the total thrust of the jack when the shield tunneling machine with the small curvature radius is propelled and the torque when the shield tunneling machine is propelled.

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