阅读说明：本技术 一种小曲率半径盾构隧道推进参数确定方法 (Method for determining propelling parameters of shield tunnel with small curvature radius ) 是由 黄求新 安刚建 韩清 张鹏飞 孙立强 袁正璞 高国平 王仕成 张伟 雷荡 潘茂 于 2021-09-28 设计创作，主要内容包括：本申请提供了一种小曲率半径盾构隧道推进参数确定方法,包括：根据小曲率半径盾构隧道盾构机推进时,盾构机与土体的摩擦系数、小曲率半径盾构隧道的土体浮容重、盾构机的法向土压力系数、盾构机的等效容重,基于预设的盾周土压力模型,确定盾构机推进时的盾周土压力；根据小曲率半径盾构隧道盾构机推进时,盾构机的正面土压力调整系数、盾构机的静止土压力系数、盾构机的水压力系数,基于预设的盾头土压力模型,确定盾构机推进时的盾头土压力；根据盾周土压力和盾头土压力,确定盾构机推进时的千斤顶总推力；根据小曲率半径盾构隧道的土体弹簧常数、盾构机转动过一次的转角,基于预设的推进转矩模型,确定盾构机推进时的转矩。(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 shield surrounding soil pressure during the propelling of the shield tunneling machine based on a preset shield surrounding soil pressure model according to a friction coefficient of the shield tunneling machine and a soil body, a soil body floating volume weight of the shield tunneling machine with small curvature radius, a normal soil pressure coefficient of the shield tunneling machine and an 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.)

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

step 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;

step S3, determining the total thrust of a jack when the shield machine with small curvature radius is propelled according to the soil pressure around the shield when the shield machine with small curvature radius is propelled and the soil pressure at the shield head when the shield machine with small curvature radius is propelled;

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

2. The small radius of curvature 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_θRepresenting 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 soil layer thickness of the shield tunnel with the small curvature radius; gamma's'_εRepresenting the equivalent volume weight of the shield machine; theta representsAnd an included angle between any point on a cutter head of the shield tunneling machine and the horizontal plane.

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

calculating normal soil pressure coefficient K of shield machine_θ；

Wherein, K_hThe horizontal soil pressure coefficient around the shield machine is obtained; k_vAnd expressing the vertical soil pressure coefficient around the shield machine.

4. The small radius of curvature 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; k₀The 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_wRepresenting the water pressure coefficient of the shield machine; gamma ray_wRepresents the water volume weight; h represents the soil of the shield tunnel with small curvature radiusLayer thickness.

5. The method for determining the advancing parameters of the shield tunnel with small curvature radius according to 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＝K₀。

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 determining the total thrust of the jack when the shield tunnel with the small curvature radius is propelled according to the soil pressure around the shield when the shield tunnel with the small curvature radius is propelled and the soil pressure at the shield head when the shield tunnel with the small curvature radius is propelled specifically includes:

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 radius of curvature 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_fShowing 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_sThe elastic modulus of the soil body; e_pThe elastic modulus of the shield machine; i is_pThe 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 the following steps:

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

Technical Field

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

Background

With the rapid development of society and economy, the urbanization process is continuously intensified, the utilization of ground resources tends to be saturated, and the development and utilization of urban underground space resources become one of the important directions of social sustainable development. The shield tunnel construction is one of the main methods for underground tunnel construction such as subway and the like due to the advantages of high construction speed, safety, high efficiency, small interference to urban ground environment and the like. However, with the further development of urban underground space, due to the influence of deep foundation pits, underground pipelines and the like, the subway axis design sometimes has a small radius curve, and higher requirements are put forward for the shield construction control technology.

The control difficulty of the small curvature radius tunnel axis is large. Because the shield machine is a linear rigid body, in order to fit the tunnel axis with the designed axis, continuous deviation rectification is required in the propelling process so as to accurately control the posture of the shield machine. The shield machine realizes curve turning and deviation correction by adjusting the shield propelling pressure, the smaller the radius of the axis of the tunnel is, the lower the deviation correction sensitivity is, the more difficult the axis is to control, and the difficulty of axis control and deviation correction is greatly increased.

In actual engineering, the distribution of the jack force system is usually adjusted according to construction experience, so that the construction difficulty is increased, and great potential safety hazards exist. Therefore, there is a need to provide an improved solution to the above-mentioned deficiencies of the prior art.

Disclosure of Invention

The application aims to provide a method for determining a propelling parameter of a shield tunnel with a small curvature radius, so as to solve or alleviate the problems in the prior art.

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

the application provides a method for determining a propelling parameter of a shield tunnel with a small curvature radius, which comprises the following steps: step S1, determining shield circumferential soil pressure when the shield machine with small curvature radius advances according to the friction coefficient of the shield machine and the soil body, the soil body floating volume weight of the shield tunnel with small curvature radius, the normal soil pressure coefficient of the shield machine and the equivalent volume weight of the shield machine when the shield machine with small curvature radius advances, and based on a preset shield circumferential soil pressure model; step 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; step S3, determining the total thrust of a jack when the shield machine with small curvature radius is propelled according to the soil pressure around the shield when the shield machine with small curvature radius is propelled and the soil pressure at the shield head when the shield machine with small curvature radius is propelled; and S4, determining the torque of the shield machine with small curvature radius when the shield machine with small curvature radius advances based on a preset advancing torque model according to the soil body spring constant of the shield tunnel with small curvature radius and the corner of the shield machine which rotates once.

Preferably, in step S1, based on the preset soil surrounding pressure model:

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_θRepresenting 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 soil layer thickness of the shield tunnel with the small curvature radius; gamma's'_εRepresenting the equivalent volume weight of the shield machine; and theta represents the included angle between any point on the cutter head of the shield tunneling machine and the horizontal plane.

Preferably, in step S1, according to the formula:

calculating normal soil pressure coefficient K of shield machine_θ；

Wherein, K_hThe horizontal soil pressure coefficient around the shield machine is obtained; k_vAnd expressing the vertical soil pressure coefficient around the shield machine.

Preferably, in step S2, based on the preset shield head soil pressure model:

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; k₀The 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_wRepresenting the water pressure coefficient of the shield machine; gamma ray_wRepresents the water volume weight; h represents the soil layer thickness of the shield tunnel with the small curvature radius.

Preferably, in step S2, the water pressure coefficient K of the shield machine in sandy soil and silty soil strata_w1 is ═ 1; in a cohesive soil layer, the water pressure coefficient K of the shield machine_w＝K₀。

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

Preferably, in step S3, the determining, according to the shield earth pressure when the shield tunneling machine with the small radius of curvature is advanced and the shield head earth pressure when the shield tunneling machine with the small radius of curvature is advanced, the total jack thrust when the shield tunneling machine with the small radius of curvature is advanced specifically includes: 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.

Preferably, 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_fShowing the anterior shield length of the shield machine.

Preferably, 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_sIs a soil body elastic model; e_pAn elastic model of the shield machine; i is_pThe moment of inertia of the shield tunneling machine; v is the poisson's ratio of the soil mass.

Preferably, the method for determining the small curvature radius shield tunnel propulsion parameter further includes: and distributing the thrust for the shield machine to rotate a primary corner according to the total thrust of the jack when the shield machine with the small curvature radius is propelled and the torque when the shield machine is propelled.

Compared with the closest prior art, the technical scheme of the embodiment of the application has the following beneficial effects:

the method for determining the propelling parameters of the shield tunnel with the small curvature radius comprehensively considers the soil geological conditions and the influence of an equipment structure on the shield machine, quickly and accurately calculates the total jack thrust and the torque in the propelling process of the shield machine with the small curvature radius, provides reliable basis for the track planning, the deviation correction and the like of the shield machine with the small curvature radius, and is favorable for accurately distributing and adjusting the thrust in the turning process of the shield machine with the small curvature radius in the construction process.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. Wherein:

fig. 1 is a schematic flow chart of a method for determining a propulsion parameter of a shield tunnel with a small curvature radius according to some embodiments of the present application;

FIG. 2 illustrates shield shell normal static soil pressure of a shield tunneling machine according to some embodiments of the present application;

fig. 3 is a shield head pressure diagram of a shield tunneling machine according to some embodiments of the present application;

FIG. 4 is a schematic top view of a shield tunneling machine curve segment shield circumferential earth pressure increase provided in accordance with some embodiments of the present application;

FIG. 5 is a schematic top view of shield head soil pressure increment for a curved segment of a shield tunneling machine according to some embodiments of the present application;

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

Detailed Description

The present application will be described in detail below with reference to the embodiments with reference to the attached drawings. The various examples are provided by way of explanation of the application and are not limiting of 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 instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. It is therefore intended that the present application cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

In the description of the present application, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description of the present application but do not require that the present application must be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. The terms "connected," "connected," and "disposed" as used herein are intended to be broadly construed, and may include, for example, fixed and removable connections; can be directly connected or indirectly connected through intermediate components; the specific meaning of the above terms can be understood by those of ordinary skill in the art as appropriate.

Fig. 1 is a schematic flow chart of a method for determining a propulsion parameter of a shield tunnel with a small curvature radius according to some embodiments of the present application; as shown in fig. 1, the method for determining the propulsion parameters of the shield tunnel with small curvature radius includes:

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

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

wherein, F_sThe unit of the soil pressure around the shield when the shield tunneling machine with small curvature radius is propelled is kilonewton (kN); mu represents the friction coefficient of the shield with small curvature radius and the soil bodyNo dimension; l represents the total length of the shield tunneling machine and is expressed in meters (m); gamma' represents the floating volume weight of the soil body of the shield tunnel with small curvature radius, and the unit is kilonewton per cubic meter (kN/m)³)；K_θThe normal soil pressure coefficient of the shield machine is represented, and the method is dimensionless; d represents the diameter of a cutter head of the shield tunneling machine and the unit is meter (m); h represents the thickness of the soil layer of the shield tunnel with small curvature radius, and the unit is meter (m); gamma's'_εThe equivalent volume weight of the shield machine is expressed in kilonewtons per cubic meter (kN/m)³) (ii) a And theta represents the included angle between any point on the cutter head of the shield tunneling machine and the horizontal plane.

In the embodiment of the application, the equivalent volume weight gamma 'of the shield machine'_εDetermined according to equation (2), equation (2) is as follows:

wherein, w is the gravity of the shield machine and the accessory equipment thereof, and the unit is kilonewton (kN).

In the embodiment of the application, the normal soil pressure coefficient K of the shield machine_θDetermined according to (3), equation (3) is as follows:

wherein, K_hThe horizontal soil pressure coefficient around the shield machine is obtained; k_vAnd (4) representing the vertical soil pressure coefficient around the shield tunneling machine.

In the embodiment of the application, the pressure coefficient K is applied to the vertical soil_vIn the soft clay stratum, the top soil pressure of the tunnel is defined to be equal to the weight of the overlying soil column, namely the vertical soil pressure is equal to the self-weight stress of the soil body, therefore, K_v1. For horizontal earth pressure coefficient K_hObtained by experimentation or using K_h＝K₀Wherein, K is₀Static soil pressure coefficient (dimensionless).

In the examples of the present application, the coefficient of static soil pressure K_hDetermined according to equation (4), equation (4) is as follows:

wherein the content of the first and second substances,the internal friction angle of the soil body is expressed in (rad). Here, the internal friction angle of the soil body is measured by performing a soil test on the soil body, and is not described herein any more.

In the embodiment of the present application, the normal static soil pressure applied to the shield shell of the shield tunneling machine is as shown in fig. 2, and the soil pressure F around the shield during the propelling of the shield tunneling machine with a small curvature radius can be obtained by integrating the normal soil pressure applied to the shield shell in the circumferential direction_s. Specifically, the normal earth pressure on the top of the shield tunneling machine is K_vGamma' H; the normal soil pressure on the side surface of the shield machine isThe normal soil pressure on the bottom of the shield machine is K_v(γ′_εH+γ′_εD)。

Step S2, determining shield head soil pressure when the shield machine with small curvature radius 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 with small curvature radius is propelled, and based on a preset shield head soil pressure model;

in the embodiment of the present application, the preset shield head soil pressure model is shown in formula (5), where formula (5) is as follows:

wherein, F_headThe shield head soil pressure when the shield tunneling machine with small curvature radius is propelled is expressed in kilonewtons (kN); lambda represents the front soil pressure adjustment coefficient of the shield tunneling machine and is dimensionless; d represents the diameter of a cutter head of the shield tunneling machine and the unit is meter (m);K₀the static soil pressure coefficient of the shield machine is shown, and the method is dimensionless, the internal friction angle of the soil body; gamma' represents the floating volume weight of the soil body of the shield tunnel with small curvature radius, and the unit is kilonewton per cubic meter (kN/m)³)；K_wThe water pressure coefficient of the shield machine is expressed, and the dimension is not existed; gamma ray_wExpressed as water volume weight in kilonewtons per cubic meter (kN/m)³) (ii) a H represents the thickness of the soil layer of the shield tunnel with small curvature radius, and the unit is meter (m).

In the embodiment of the application, the water pressure coefficient K of the shield machine_wThe hydraulic pressure coefficient K of the shield machine in the stratum with better permeability such as sandy soil and silty soil stratum_w1 is ═ 1; in cohesive soil layer, the water pressure coefficient K of the shield machine_w＝K₀. The front soil pressure adjustment coefficient lambda of the shield machine is generally determined according to the factors such as the property change after the soil disturbance, the propelling speed of the shield machine, the overload condition of the shield machine and the like, and when the soil layer is cohesive soil, the value range of the front soil pressure adjustment coefficient lambda of the shield machine is [1.05, 1.12]]。

In the embodiment of the present application, the pressure applied to the shield head of the shield machine is as shown in fig. 3, and in a normal case, the shield head (cutterhead) of the shield machine is subjected to the combined action of earth pressure (inside) and water pressure (outside), and it can be known that the pressure applied to the top of the cutterhead is: (K)₀γ′H+K_wγ_wH) (ii) a The pressure that the blade disc bottom received does: k₀γ′(H+D)+K_wγ_w(H + D), so that the average pressure experienced by the middle of the cutterhead is: the shield head soil pressure F of the shield tunnel shield machine with small curvature radius can be determined according to the average pressure on the middle part of the cutter head and the area of the cutter head_head. Here, the groundwater level (groundwater level) is set to be parallel to the earth plane.

Step S3, determining the total jack thrust when the shield machine with small curvature radius is propelled according to the shield soil pressure around the shield machine with small curvature radius when the shield machine with small curvature radius is propelled and the shield head soil pressure when the shield machine with small curvature radius is propelled;

in the embodiment of the application, the earth pressure around the shield when the shield machine with the small curvature radius is propelled and the earth pressure at the shield head when the shield machine with the small curvature radius is propelled are summed, and the total thrust of the jack when the shield machine with the small curvature radius is propelled is determined. Specifically, the total jack thrust F when the shield machine is propelled_jackDetermined according to equation (6), equation (6) is as follows:

F_jack＝F_s+F_head………………………………(6)

in the embodiment of the application, in the propelling process of the shield machine, the propelling force (divided into a left driving force and a right driving force according to the area) is usually applied in blocks, and the total propelling force of the jack during propelling is the sum of the left driving force and the right driving force.

And S4, determining the torque of the shield machine with small curvature radius when the shield machine advances according to the earth body spring constant of the shield tunnel with small curvature radius and the corner of the shield machine which rotates once, and based on a preset advancing torque model.

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

wherein k represents the soil body spring constant of the shield tunnel with small curvature radius, and the unit is kilonewton per meter (kN/m); alpha represents the rotation angle of the shield machine which rotates once, and the unit is (rad);d represents the diameter of a cutter head of the shield tunneling machine and the unit is meter (m); l is_fThe unit of the front shield length of the shield machine is meter (m).

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

wherein E is_sThe soil elasticity modulus is measured in kilopascals (kPa); e_pThe elastic modulus of the shield machine is expressed in kilopascal (kPa); i is_pIs the inertia moment of the shield machine and has the unit of cubic meter (m)⁴) (ii) a v is the Poisson's ratio of the soil body and is dimensionless. Here, the elastic modulus of the shield machine is related to the material (steel) of the shield machine, and in general, the elastic modulus of the shield machine adopts the moment of inertia about the center of a circle.

In the embodiment of the application, the shield shell and the shield head can be extruded or far away from the soil body due to the rotation of the shield tunneling machine, and further the rotation center (O)₁) A moment is generated. The hinged position is arranged in the middle of the shield machine, the shield machine is divided into a front shield (comprising a cutter head) and a rear shield, and the part of the shield machine which actually extrudes (or is far away from) the soil body is mainly the front shield. The shield machine has the advantages that the position pushed by the jack of the shield machine is in the middle of the shield machine, and the rotation center (O) of the shield machine₁) Fig. 4 shows the change amount of the earth pressure around the anterior shield after rotation at the end of the anterior shield of the shield machine.

As shown in FIG. 4, the former shield of the shield machine extrudes the soil to generate passive soil pressure increment of delta sigma_p(ii) a The active soil pressure increment generated by the rear shield far away from the soil body of the shield machine is delta sigma_aWherein the passive earth pressure increase Δ σ_pAnd active soil pressure increase Δ σ_aLinearly changing on the shield shell. With shield machine rotation center (O)₁) As a boundary, the stress of soil bodies on two sides of the shield machine can be divided into an active area and a passive area, wherein when the shield machine rotates, the elastic moduli of the active area and the passive area are consistent, namely the elastic moduli of the active area and the passive area are opposite to the center (O) of the shield machine₁) The torque of (2) is the same. Load increment of shield shell (active soil pressure increment and passive soil pressure increment)) To O₁Total torque M generated_shieldAs shown in equation (9), equation (9) is as follows:

wherein L is_fThe unit of the front shield length of the shield machine is meter (m); alpha represents the rotation angle of the shield machine rotated once and is given by (rad). The static soil pressure and water pressure on the shield head are symmetrical about the z-axis, so that the torque on the z-axis is zero, and the stress increment after rotation generates a torque action on the z-axis, as shown in fig. 5.

As can be seen from fig. 5, 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, and the unit is meter (m). According to the symmetry, the shield head stress increment can be divided into 4 parts according to quadrants, and the moment generated by each part of the load increment to the z axis is the same. Thus, the total torque M of shield head soil pressure increment to the z-axis_headAs shown in formula (11), formula (11) is as follows:

increment of shield shell load to O₁Total torque M generated_shieldAnd total torque M of shield head soil pressure increment to z axis_headAnd the torque of the shield machine with small curvature radius in the propelling process can be obtained.

In the implementation of the application, in the shield tunnel with small curvature radius, the values of the parameters of the shield thrust resistance are shown in table 1: TABLE 1

In some optional embodiments, the method for determining the propulsion parameter of the shield tunnel with the small curvature radius further comprises: and distributing the thrust for the shield machine to rotate a primary corner according to the total thrust of a jack when the shield machine of the shield tunnel with small curvature radius is propelled and the torque when the shield machine is propelled.

Specifically, the moment difference generated by the left driving force and the right driving force when the shield tunneling machine rotates for a rotation angle alpha can be determined according to the torque when the shield tunneling machine is propelled. Furthermore, the left driving force and the right driving force can be determined when the shield tunneling machine is propelled by combining the total jack thrust (the sum of the left driving force and the right driving force) when the shield tunneling machine with small curvature radius is propelled.

In the embodiment of the application, the influence of soil layer geological conditions and equipment structures on the shield tunneling machine is comprehensively considered, the total jack thrust and the moment in the propelling process of the shield tunneling machine with the small curvature radius are quickly and accurately calculated, reliable bases are provided for track planning, deviation correction and the like of the shield tunneling machine with the small curvature radius, and the accurate distribution and real-time adjustment of the thrust of the shield tunneling machine with the small curvature radius in the turning process are facilitated.

Fig. 6 is a schematic structural diagram of a small curvature radius shield tunnel propulsion parameter determination system according to some embodiments of the present application; as shown in fig. 6, the system for determining the propulsion parameters of the shield tunnel with small curvature radius comprises: the shield head soil pressure unit is connected with the shield head soil pressure unit;

the shield-surrounding soil pressure unit is configured to determine shield-surrounding soil pressure when the shield machine with the small curvature radius is propelled based on a preset shield-surrounding 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 the 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 the small curvature radius is propelled;

the shield head soil pressure unit is configured to determine shield head soil pressure when the shield machine with the 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 the small curvature radius is propelled;

the total thrust unit is configured to determine the total thrust of the 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 the torque unit is configured to determine the torque of the shield machine with the small curvature radius during propulsion based on a preset propulsion torque model 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.

The system for determining the propelling parameters of the shield tunnel with the small curvature radius provided by the embodiment of the application can realize the steps and the process of the method for determining the propelling parameters of the shield tunnel with the small curvature radius provided by any embodiment, and achieve the same technical effects, and the method is not repeated herein.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.