Shield soil cabin pressure control method under air pressure auxiliary tunneling mode

Abstract

The application is suitable for the technical field of earth pressure balance shield tunneling safety, and provides a shield soil cabin pressure control method in a pneumatic auxiliary tunneling mode, which comprises the following steps: obtaining the vertical effective stress distribution of the soil in the soil cabin according to the gas, solid and liquid three-phase volume percentages, pore water pressure and air pressure of the foam improved spoil, and considering the compressibility and unsaturation thereof; determining the air-soil mixed pressure distribution in the soil cabin according to the air-soil interface height in the soil cabin; determining the air-soil mixed pressure distribution at the next moment according to the screw conveyor speed, shield tunneling speed and air pressure loss amount in the soil cabin; and adjusting the shield tunneling speed and screw speed so that the air-soil mixed pressure resultant force in the soil cabin is between the active soil pressure resultant force and the passive soil pressure resultant force of the excavation stratum. The application can improve the control precision of the air-soil mixed pressure in the shield soil cabin in the pneumatic auxiliary tunneling mode.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of earth pressure balance shield tunneling safety, and particularly relates to a shield soil cabin pressure control method in a pressure-assisted tunneling mode. BACKGROUND

[0002] The earth pressure balance shield pressure-assisted tunneling mode is a new shield construction method proposed by the tunnel engineering field in China. In the process of earth pressure balance shield tunneling, the pressure of the sealed cabin is controlled by adjusting the advancing speed, screw conveyor speed and sealed cabin pressure to balance the sealed cabin pressure and water and soil pressure, thereby ensuring the stability of the tunneling interface. However, with the change of the stratum, the tunneling parameters such as the advancing speed, screw speed and shield sealed cabin pressure need to be continuously adjusted to control the dynamic balance of the air-soil mixed pressure of the tunneling interface and the water and soil pressure. In the pressure-assisted tunneling mode, the air pressure in the shield soil cabin coexists with the muck, and the air-soil pressure distribution characteristics of the soil cabin are related to the air permeability of the muck and are also affected by the air permeation behavior of the excavated stratum. Under the dynamic action of "air infiltration", "underground water seepage" and "muck migration", the shield sealed cabin pressure control with the goal of "balancing the water and soil pressure of the excavation face" is extremely complex, and the key lies in accurately calculating the air-soil mixed pressure distribution in the shield sealed cabin considering the air pressure loss.

[0003] Although a large number of studies have been based on field data, the relationship between the sealed cabin air pressure, screw speed, advancing speed and stratum has been preliminarily revealed. However, these studies often start from data without explaining the relationship between these construction parameters and the air-soil mixed pressure of the tunneling interface from a physical model, resulting in low control accuracy of the air-soil mixed pressure of the shield sealed cabin. SUMMARY

[0004] The application provides a shield soil cabin pressure control method in a pressure-assisted tunneling mode, which can solve the problem of low control accuracy of the air-soil mixed pressure of the shield sealed cabin.

[0005] The application provides a shield soil cabin pressure control method in a pressure-assisted tunneling mode, which can solve the problem of low control accuracy of the air-soil mixed pressure of the shield sealed cabin.

[0006] The change of the volume percentage of the air, solid and liquid phases of the muck, the pore water pressure and the pore air pressure are obtained, the compressibility and unsaturated characteristics of the foam improved muck are considered, and the friction between the muck in the sealed cabin and the cabin wall, the permeability of the muck and the self weight of the muck at the current time are obtained; the sealed cabin is the sealed cabin of the shield machine, and the permeability is caused by the infiltration of water and air into the muck;

[0007] According to the friction between the muck in the sealed cabin and the cabin wall, the permeability and the self weight of the muck, a vertical effective stress distribution balance equation of the foam improved muck in the soil cabin is established based on the force balance of the muck in the sealed cabin;

[0008] According to the established vertical effective stress distribution of the foam improved soil in the soil chamber and the current height of the air-soil interface in the soil chamber, the current air-soil mixed pressure resultant force in the soil chamber is determined;

[0009] According to the gas permeation characteristic test of the unsaturated soil body, the stratum and the foam improved soil permeation coefficient are measured, and the current air pressure loss in the sealed chamber is determined;

[0010] According to the rotation speed of the screw conveyor on the construction site, the tunneling speed of the shield machine, the current air-soil mixed pressure in the sealed chamber and the air pressure loss in the sealed chamber, the air-soil mixed pressure resultant force of the next time of the sealed chamber is obtained;

[0011] The active soil pressure resultant force and the passive soil pressure resultant force of the stratum are obtained;

[0012] By adjusting the tunneling speed of the shield machine and the rotation speed of the screw machine, the air-soil mixed pressure resultant force in the soil chamber is adjusted to be between the active soil pressure resultant force and the passive soil pressure resultant force of the stratum in front of the excavation face, so as to ensure the stability of the tunneling stratum.

[0013] Optionally, the calculation formula of the groundwater seepage force is:

[0014]

[0015] Wherein, F1 represents the groundwater seepage force, γ w represents the unit weight of water, i 渣土 represents the hydraulic gradient when the water infiltrates into the slag soil, P represents the air pressure in the shield sealed chamber, P 标态 represents the standard atmospheric pressure, H represents the height of the air-soil layer interface in the sealed chamber, B represents the length of the sealed chamber, D represents the diameter of the cutter head of the shield machine, z represents the height of the slag soil from the bottom of the sealed chamber, and Δz represents the average thickness of the slag soil in the vertical direction when the discrete solution is performed;

[0016] The calculation formula of the gas permeation force is:

[0017]

[0018] P(z) = 10(P 标态 +i 渣土 z)

[0019]

[0020]

[0021] Wherein, F2 represents the gas permeation force received by the slag soil, P(z) is the average pressure of the z height pore gas converted from mm water column to Pa, φ 等效固相，渣土 (z) represents the volume percentage of the slag soil solid phase at the position z in the sealed chamber when the compressibility of the improved slag soil is considered, φ等效液相，渣土 (z) represents the volume percentage of the liquid phase of the slag soil at position z in the sealed cabin considering the improvement of the compressibility of the slag soil, u 地层 represents the pore water pressure, ρ represents the density of the slag soil, ω represents the water content of the slag soil, G s represents the relative density of the particles of the slag soil, u(z) represents the pore water, gas pressure;

[0022] The calculation formula of the friction force between the slag soil in the sealed cabin and the sealed cabin shell is:

[0023]

[0024] wherein, F3 represents the friction force, μ represents the friction coefficient of the slag soil and the sealed cabin shell,

[0025] σ z (z) = u(z) + σ' z (z) = f(u(z))

[0026]

[0027] u(z) represents the pore water, gas pressure, σ' z (z) represents the vertical effective stress, σ z (z) represents the vertical stress of the slag soil in the sealed cabin at the current moment, f represents the relationship between σ z (z) and u(z), u w (z) represents the pore water pressure, P(z) represents the pore gas pressure;

[0028] The calculation formula of the self-weight of the slag soil is:

[0029]

[0030] wherein, F4 represents the self-weight, G s represents the relative density of the particles of the slag soil.

[0031] Optionally, based on the friction force, the penetration force and the self-weight of the slag soil in the sealed cabin and the sealed cabin shell, the vertical effective stress distribution balance equation of the foam improved slag soil in the soil cabin is established based on the force balance of the slag soil in the sealed cabin, including:

[0032] Based on the motion of the overall slag soil in the sealed cabin, the relational expression is constructed:

[0033]

[0034] Based on the relational expression, the expression of φ 等效固相，渣土 (z), the expression of φ 等效液相，渣土 (z), and σ z(z) = f(u(z)) is used to solve the vertical effective stress of the current time sealing cabin slag soil σ z (z) = f(u(z)) is used to solve the vertical effective stress of the current time sealing cabin slag soil σ

[0035] Optionally, the current time t sealing cabin gas and soil pressure force is:

[0036]

[0037] Wherein, F 密封舱 (t) represents the current time sealing cabin gas and soil pressure force, P(t) S(t) represents the current time sealing cabin gas pressure, represents the current time sealing cabin soil pressure, P(t) represents the current time shield sealing cabin gas pressure, S(t) represents the current time sealing cabin soil layer top gas pressure action area;

[0038]

[0039] H(t) represents the current time sealing cabin soil gas layer interface height, N represents the number of layers divided when solving the slag soil layering, σ z (H(t)-iΔz) represents the current time position for H(t)-iΔz vertical stress, i = 1, 2, …, N;

[0040]

[0041] v 土层，输走 is the volume rate of sealing cabin slag soil transported out by screw machine, v 土层，输走 η represents the soil discharge efficiency of shield machine, ω 螺旋机转速 (t) represents the current time shield machine screw machine speed, A s represents the effective soil discharge area of shield machine screw machine, l represents the pitch of shield machine screw machine; V 土层，进入 is the volume rate of stratum entering the sealing cabin during shield advancing, V 推进 (t) represents the current time shield machine advancing speed;

[0042]

[0043] Optionally, according to the unsaturated soil gas permeation characteristics test, the stratum and foam improved soil permeability coefficient is measured, the current time sealing cabin gas pressure loss is determined, and the next time sealing cabin gas and soil pressure force is obtained according to the construction site screw conveyor speed, shield machine advancing speed, current time sealing cabin gas and soil pressure and sealing cabin gas pressure loss, including:

[0044] The height H(t+Δt) of the gas-soil interface in the sealing cabin at the next time is calculated by the formula

[0045] The air pressure P(t+dt) in the sealing cabin at the next time is calculated by the formula

[0046] The air pressure loss q(t) in the sealing cabin at the current time is calculated by the formula q(t)=q1(t)+q2(t).

[0047] P 标态 q1(t+Δt)=P 标态 q1(t)+P 标态 k sq1 i 地层 S(t)Δt

[0048]

[0049] The total force F(t+Δt) of the air-soil mixture in the sealing cabin at the next time is calculated by the formula 密封舱

[0050]

[0051] Wherein, t represents the current time, Δt represents the time difference between the next time and the current time, q1(t) represents the cumulative amount of gas flowing into the stratum at the current time, q2(t) represents the cumulative amount of gas flowing into the pores of the muck in the sealing cabin at the current time, q1(t+Δt) represents the cumulative amount of gas flowing into the stratum at the next time, k sq1 represents the permeability coefficient of the stratum, h represents the depth of the cutter head of the shield machine, q2(t+Δt) represents the cumulative amount of gas flowing into the pores of the muck in the sealing cabin at the next time, k sq2 represents the permeability coefficient of the muck.

[0052] Optionally, the formula for calculating the total force of the active earth pressure of the stratum is:

[0053]

[0054] Wherein, F 主动土压力 represents the total force of the active earth pressure of the stratum, k 主动 represents the active earth pressure coefficient, represents the internal friction angle of the tunneling stratum, γ i represents the unit weight of the i-th layer of soil in the tunneling stratum, i represents the depth of the cutter head of the shield machine, h i represents the height of the top of the i-th layer of soil, c i represents the cohesion of the i-th layer of soil in the tunneling stratum.​​​

[0055] Optionally, the formula for calculating the resultant passive earth pressure of the strata is:

[0056]

[0057] Among them, F 被动土压力 k represents the resultant passive earth pressure in the strata. 被动 Indicates the passive earth pressure coefficient.

[0058] Optional, F 主动土压力 ≤F 密封舱 (t+Δt)≤F 被动土压力 H min ≤H(t+Δt)≤H max H min H represents the preset minimum height of the soil-air interface within the sealed chamber. max This indicates the preset maximum height of the soil-air interface within the sealed chamber.

[0059] Optionally, the tunneling speed and auger rotation speed of the tunnel boring machine can be adjusted, including:

[0060] If F 密封舱 (t+Δt) <F 主动土压力 This reduces the tunneling speed of the tunnel boring machine, increases the speed of the tunnel boring machine's screw conveyor, and increases the air pressure in the tunnel's sealed chamber.

[0061] If F 密封舱 (t+Δt)>F 被动土压力 This increases the tunneling speed of the tunnel boring machine, reduces the speed of the tunnel boring machine's screw conveyor, and decreases the air pressure in the tunnel's sealed chamber.

[0062] If H(t+Δt>H max This would reduce the tunneling speed of the tunnel boring machine and increase the rotation speed of the tunnel boring machine's auger.

[0063] If H(t+Δt) <H min This increases the tunneling speed of the tunnel boring machine and decreases the rotation speed of the tunnel boring machine's screw conveyor.

[0064] Optionally, the control methods also include:

[0065] The air pressure P(t) in the shield tunnel's sealed chamber at the current moment is calculated using the following formula:

[0066]

[0067] Wherein, t0 represents the time of last air pressure supplement, S(t0+jΔt) represents the air chamber acting area of the jth time interval from t0 to t divided by Δt interval when performing refined solution, H(t0+jΔt) represents the soil layer interface height of the jth time interval from t0 to t divided by Δt interval.

[0068] The above scheme of the present application has the following beneficial effects:

[0069] In the embodiment of the present application, by comprehensively considering multiple factors of air, liquid infiltration, muck migration, tunneling speed, screw speed and other tunneling parameters, a sealed cabin pressure distribution physical model is constructed, the air-soil mixed pressure in the sealed cabin is accurately calculated from the essence of the stress state change of the muck in the sealed cabin, considering the seepage force of the seepage field on the muck, the resistance of the sealed cabin wall to the muck, and the air pressure loss caused by air infiltration, so that it can accurately detect whether the ground stress meets the ground stress balance condition (i.e. the air-soil mixed pressure in the soil cabin is between the active soil pressure and passive soil pressure of the excavation face), and when the stress balance condition is not met, the tunneling speed of the shield machine, the screw speed and the sealed cabin air pressure are adjusted in time, thereby realizing accurate control of the supporting force of the sealed cabin and improving the control accuracy of the supporting force of the shield sealed cabin.

[0070] Other beneficial effects of the present application will be described in detail in the subsequent specific embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0071] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0072] Figure 1 The flow chart of the shield soil cabin pressure control method in the air pressure auxiliary tunneling mode provided by an embodiment of the present application;

[0073] Figure 2 The stress schematic diagram of the muck in the sealed cabin provided by an embodiment of the present application;

[0074] Figure 3 The adjustment flow chart of the tunneling speed, screw speed, and sealed cabin air pressure provided by an embodiment of the present application;

[0075] Figure 4 The sealed cabin pressure distribution calculation model schematic diagram provided by an embodiment of the present application. DETAILED DESCRIPTION

[0076] In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular architectures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known methods, devices, circuits, and

[0077] It will be understood that the term "includes," "including," "has," "having," "comprises," "comprising," "contains" or "containing," when used in this specification and in the following claims, specifies the presence of the stated features, integers, steps, operations, elements, and / or components but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0078] It will be understood that the term "and / or," when used in this specification and in the following claims, can encompass the meaning of "and" as well as the meaning of "or," and can include any combination of one or more of the associated listed items and all possible combinations thereof.

[0079] As used in this specification and claims, the terms "if' and "when" can be interpreted to mean "upon determination" or "in response to a determination" or "in response to a detection" depending on the context. Similarly, the phrase "if determined" or "if detected [the described condition or event]" can be interpreted to mean "upon determination" or "in response to a determination" or "upon detection" or "in response to a detection [the described condition or event]" depending on the context.

[0080] In addition, the terms "first," "second," "third," etc. as used in the description and the appended claims are used only to differentiate one element from another, and do not imply a relative importance or a specific order.

[0081] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. Thus, the appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," and the like in various places throughout this specification are not necessarily referring to the same embodiment, unless otherwise specified. The terms "comprise," "comprising," "has," "having," "includes," "including," "contains," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises, has, includes, contains a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0082] In view of the low control precision of the supporting force of the shield sealing cabin at present, the embodiment of the present application provides a shield soil cabin pressure control method in a gas pressure auxiliary tunneling mode, a sealing cabin pressure distribution physical model is constructed by comprehensively considering gas, liquid infiltration, muck migration, and multiple factors of tunneling parameters, the essence of the stress state change of the muck in the sealing cabin is realized, the sealing cabin gas-soil mixed pressure is accurately calculated by considering the penetration force, the resistance of the sealing cabin wall to the muck, and the gas pressure loss caused by gas infiltration, so that whether the ground stress meets the ground stress balance condition (i.e. the gas-soil mixed pressure in the soil cabin is between the active soil pressure and the passive soil pressure of the ground in front of the excavation face) can be accurately detected, and when the stress balance condition is not met, the tunneling speed of the shield machine, the screw speed and the sealing cabin gas pressure are adjusted in time, and then the accurate control of the supporting force of the sealing cabin is realized, and the control precision of the supporting force of the shield sealing cabin is improved.

[0083] The shield soil cabin pressure control method in a gas pressure auxiliary tunneling mode provided by the present application will be exemplarily described below in combination with specific embodiments.

[0084] In order to facilitate understanding of the shield soil cabin pressure control method in a gas pressure auxiliary tunneling mode provided by the present application, the related parameters involved in the following embodiments are explained first.

[0085] Direct parameters (input parameters): muck parameters: density p (g / cm 3 ), water content w, particle relative density G s , cohesion c (kPa), internal friction angle Pore water pressure u 地层 (kPa); shield machine parameters: cutter head diameter D (m), cutter head top buried depth h (m), tunneling speed v 推进 (m / s), screw pitch l (m), muck discharge efficiency η, effective muck discharge area A s (m 2 ), screw speed ω 螺旋机转速 (rad / s), shield sealing cabin gas pressure P (kPa), sealing cabin length B (m), foam injection ratio FIR, foam expansion ratio FER, gas-soil interface height H0 (m) in the shield sealing cabin at the beginning of tunneling; ground gas permeability coefficient k sq1 (m / s), muck gas permeability coefficient k sq2 .

[0086] Indirect parameters: volume percentages of gas, solid and liquid phases in the ground: φ 固相，地层 , φ 液相，地层 , φ 气相，地层 ; volume percentages of gas, solid and liquid phases of the muck in the screw conveyor: φ 固相，改良渣土 , φ 液相，改良渣土 , φ 气相，改良渣土The volume percentages of the gas, solid and liquid phases of the muck in the sealed cabin at different positions and different times: φ 等效固相，渣土 , φ 等效液相，渣土 , φ 等效气相，渣土 and the vertical stress σ z (Pa) and the pore water pressure u(Pa); the volume rate v 土层，进入 (m 3 / s) of the stratum into the shield sealed cabin, the muck transportation rate v 土层，输走 (m 3 / s); the height H(m) of the soil-gas layer interface in the sealed cabin, the horizontal cross-sectional area S(m 2 ) of the soil-gas layer interface in the sealed cabin, the equivalent volume Q(m 3 ) of the gas in the muck pores in the sealed cabin under the standard atmospheric pressure, the air loss q(m 3 ); the hydraulic gradient i 地层 of the gas into the stratum and the hydraulic gradient i 渣土 of the gas into the muck.

[0087] Control target: the resultant force of the air-soil mixed pressure in the shield sealed cabin (i.e. the supporting force of the sealed cabin, which is also called the soil chamber) F 密封舱 (kN), the active earth pressure resultant force F 主动土压力 (kN) and the passive earth pressure resultant force F 被动土压力 (kN) of the stratum, F 主动土压力 ≤ F 密封舱 ≤ F 被动土压力 .

[0088] The model control parameters (output parameters) are v 推进 , ω 螺旋机转速 and P.

[0089] The calculation process of φ 等效固相，渣土 , φ 等效液相，渣土 and φ 等效气相，渣土 is as follows:

[0090] Due to the gas infiltration into the muck in the sealed cabin, the stress state of the muck changes. Since the stress performance of the muck is closely related to the void ratio, the volume percentages of the gas, solid and liquid phases of the muck need to be calculated.

[0091] Through the survey report, the stratum parameters in the front range of the shield tunneling face are directly obtained, i.e. the density ρ, water content w and particle relative density G s of the muck, and then the volume percentages of the gas, solid and liquid phases of the muck in the tunneling stratum are converted:

[0092]

[0093] The improved slag soil is taken from the excavated ring car, and the density, moisture content and particle relative density of the improved slag soil are measured, and the volume percentages of the gas, solid and liquid phases of the slag soil at the position of the screw conveyor are converted according to the above formula (i.e. the calculation formula of φ 固相，地层 , φ 液相，地层 , φ 气相，地层 ). The improvement effect of the same stratum is mainly determined by the addition parameters of the foam improver (foam injection ratio FIR, foam expansion ratio FER):

[0094] (φ 固相，改良渣土 , φ 液相，改良渣土 , φ 气相，改良渣土 ) = J (FIR, FER)

[0095] In the formula, J (FIR, FER) represents an empirical formula obtained from the excavated ring slag soil and indoor tests.

[0096] The volume percentages of the gas, solid and liquid phases of the slag soil at different depths in the shield sealing cabin are equivalent to the three-phase φ 等效固相，渣土 , φ 等效液相，渣土 , φ 等效气相，渣土 , and they are converted according to the pore pressure thereof. Due to the infiltration of the gas in the air chamber into the slag soil in the sealing cabin, the mass of the gas in the pore at different depths and the gas pressure are different, and the pore water pressure of the improved slag soil at different positions in the sealing cabin changes. Ignoring the compressibility of the solid and liquid phases in the soil layer in the sealing cabin, the actual volume of each phase in a unit volume is unchanged:

[0097] dV 固相，渣土 (z) = φ 固相，地层 dV

[0098] dV 液相，渣土 (z) = φ 液相，地层 dV

[0099] dV 气相，渣土 (z) = φ 气相，地层 dV

[0100] In the formula, V represents volume.

[0101] However, due to the increase in the number of moles of gas in the pore caused by the gas infiltration, the pore gas volume under the same gas pressure can be converted based on the ideal gas state equation:

[0102] u(z)φ 气相，地层 dV = u 地层 dV 等效气相，渣土 (z)

[0103]

[0104] Based on dV 固相，渣土 (z), dV 液相，渣土 (z), and dV 气相，渣土(z), u(z)φ 气相，地层 dV and dV 等效气相，渣土 (z), the expression of the equivalent three-phase at different positions can be obtained:

[0105]

[0106]

[0107]

[0108] u(z) represents the pore water, gas pressure, φ 等效固相，渣土 (z) represents the volume percentage of the solid phase of the improved soil at position z in the sealed cabin when the compressibility of the improved soil is considered, φ 等效液相，渣土 (z) represents the volume percentage of the liquid phase of the improved soil at position z in the sealed cabin when the compressibility of the improved soil is considered, u 地层 represents the pore water pressure, φ 等效气相，渣土 (z) represents the volume percentage of the gas phase of the improved soil at position z in the sealed cabin.

[0109] Further, the equivalent void ratio e 等效，渣土 (z) is obtained:

[0110]

[0111] As Figure 1 shown, the embodiment of the present application provides a shield soil cabin pressure control method in a gas pressure auxiliary tunneling mode, comprising:

[0112] Step 11, the change of the volume percentage of the gas, solid and liquid phases of the soil, the pore water pressure and the pore gas pressure are obtained, the compressibility and unsaturated characteristics of the foam improved soil are considered, and the friction between the soil in the sealed cabin and the sealed cabin wall at the current moment, the permeability of the soil and the self-weight of the soil are obtained.

[0113] The sealed cabin is the sealed cabin of the shield machine, also known as the soil bin, and the permeability is caused by the infiltration of water and gas into the soil.

[0114] As Figure 2 shown, the stress condition of the soil in the sealed cabin of the shield machine (i.e. the soil in the sealed cabin of the shield machine) is considered when seepage is considered. Since the surface pore water pressure in the sealed cabin is higher than the pore water pressure at the screw machine, the soil is subjected to the seepage-induced permeability, including the groundwater permeability and the gas permeability. The calculation formula of the groundwater permeability F1 is:

[0115]

[0116] Wherein, F1 represents the water permeability, γ w represents the unit weight of water, i 渣土indicates the hydraulic gradient when water infiltrates into the muck, P indicates the air pressure in the shield cabin, P 标态 indicates the standard atmospheric pressure, H indicates the height of the interface between the soil gas layer and the cabin, B indicates the length of the cabin, D indicates the diameter of the cutter head of the shield machine, z indicates the height of the muck from the bottom of the cabin, and Δz indicates the average thickness of the muck in the vertical direction when discrete solving is performed.

[0117] The muck is composed of solid, liquid, and gas phases. In addition to the liquid penetration force, the gas also has a penetration effect. The calculation formula of the gas penetration force is:

[0118]

[0119] P(z) = 10(P 标态 +i 渣土 z)

[0120] where F2 indicates the gas penetration force on the muck, P(z) is the average pressure of the z-height pore gas converted into Pa, φ 等效固相，渣土 (z) indicates the volume percentage of the solid phase of the muck at position z in the cabin when the compressibility of the improved muck is considered, φ 等效液相，渣土 (z) indicates the volume percentage of the liquid phase of the muck at position z in the cabin when the compressibility of the improved muck is considered.

[0121] Due to the overall downward movement of the muck, friction F3 exists between the muck and the cabin wall. The friction coefficient μ of the muck and the cabin wall can be approximately replaced by the tangent of the friction angle measured by the triaxial shear test of the shield foam improved muck. The effective stress of the improved muck is related to the pore water and gas pressures. The bubbles in the muck and the pore water both cause changes in the effective stress of the muck, and the stress on the cabin wall of the shield air pressure is the sum of the horizontal effective stress and the pore water and gas pressures. That is: σ x (z) = u(z) + Kσ' z (z), where K indicates the lateral earth pressure coefficient, K = 1, σ x (z) = σ z (z), u(z) indicates the pore water and gas pressures, σ z (z) indicates the vertical effective stress, σ z (z) = f(u(z)), σ z (z) indicates the vertical stress of the muck in the cabin at the current time, f indicates the relationship between σ z (z) and u(z).

[0122] It should be noted that the stress state of the muck in the cabin is determined by the improved void ratio. The effective stress of the improved muck is related to the pore water and gas pressures. The bubbles in the muck and the pore water both cause changes in the effective stress of the muck.

[0123]

[0124] u(z) represents pore water, gas pressure, σ z (z) represents vertical effective stress, σ z (z) represents the vertical stress of the slag soil in the sealing cabin at the current moment, f represents σ z (z) and u(z), u w (z) pore water pressure, P(z) represents pore gas pressure.

[0125] By taking in-situ soil, configuring improved soil with different improvement degrees, carrying out permeation test, and measuring corresponding pore water pressure u(z) and soil pressure and void ratio, the vertical stress σ z (z) and pore water pressure u(z) is obtained: σ z (z) = f(u(z)), f is an empirical formula obtained through indoor test.

[0126] In some embodiments of the present application, the calculation formula of the friction force F3 is:

[0127]

[0128] The calculation formula of the slag soil self-weight F4 is:

[0129]

[0130] Wherein, F4 represents the slag soil self-weight, that is, the slag soil self-weight force.

[0131] Step 12, according to the friction force, permeation force and slag soil self-weight of the slag soil in the sealing cabin and the sealing cabin wall shell, a vertical effective stress distribution balance equation of the foam improved slag soil in the soil cabin is established based on the force balance of the slag soil in the sealing cabin.

[0132] In some embodiments of the present application, the overall slag soil in the sealing cabin can be regarded as downward uniform motion, therefore, based on the motion of the overall slag soil in the sealing cabin, the following relationship is constructed:

[0133]

[0134] Based on the relationship, the expression of φ 等效固相，渣土 (z), the expression of φ 等效液相，渣土 (z), and σ z (z) = f(u(z)) to solve the vertical effective stress, the vertical stress σ z (z) of the slag soil in the sealing cabin at the current moment is obtained. Specifically, the expressions of F1, F2, F3 and F4 are substituted into the relationship, and σ z (z) is obtained, and σ zThe expression of (z) is the vertical effective stress distribution balance equation mentioned above, σ z (z-Δz) represents the vertical stress at the z-Δz position.

[0135] Specifically, the above relationship is first based on the formula σ z (z) = f(u(z)), φ 等效固相，渣土 (z) is converted into the expression of the pore water pressure, the top of the soil layer in the sealed cabin is considered to be subjected to a vertical uniform gas pressure P, the soil layer in the sealed cabin is discretized, and the pore water pressure field u(z) is solved layer by layer from top to bottom, and then based on the expression of φ 等效液相，渣土 (z) = f(u(z)), φ 等效气相，渣土 (z) is converted into the expression of the pore water pressure, the top of the soil layer in the sealed cabin is considered to be subjected to a vertical uniform gas pressure P, the soil layer in the sealed cabin is discretized, and the pore water pressure field u(z) is solved layer by layer from top to bottom, and then based on the expression of φ 等效固相，渣土 (z) = f(u(z)), φ 等效液相，渣土(z) (z) = f(u(z)), σ z (z) = f(u(z)), σ z (z) is solved, and finally the vertical stress field σ

[0136] Step 13, according to the established vertical effective stress distribution of the foam improved soil in the soil cabin and the current height of the gas-soil interface in the soil cabin, the current gas-soil mixed pressure force in the soil cabin is determined.

[0137] Step 14, according to the gas permeability test of the unsaturated soil body, the gas permeability coefficient of the stratum and the foam improved soil is measured to determine the gas pressure loss amount in the sealed cabin at the current time.

[0138] Step 15, according to the rotation speed of the screw conveyor on the construction site, the tunneling speed of the shield machine, the gas-soil mixed pressure of the sealed cabin at the current time and the gas pressure loss amount in the sealed cabin, the gas-soil mixed pressure force of the sealed cabin at the next time is obtained.

[0139] In some embodiments of the present application, the supporting force of the sealed cabin is composed of the gas pressure and the soil pressure.

[0140] Specifically, the current gas-soil mixed pressure force F 密封舱 (t) of the sealed cabin at the current time t is:

[0141]

[0142] Wherein, F 密封舱 (t) represents the current gas-soil mixed pressure force (i.e. supporting force) of the sealed cabin, P(t)S(t) represents the current gas pressure in the sealed cabin, represents the current soil pressure in the sealed cabin, P(t) represents the current gas pressure of the shield sealed cabin, and S(t) represents the current gas pressure acting area of the top of the soil layer in the sealed cabin.

[0143]

[0144] H(t) represents the height of the interface between the soil and the gas layer in the sealing cabin at the current time, N represents the number of layers divided when the discrete solution of the slag soil layering is performed, σ z (H(t)-iΔz) represents the vertical stress at the position of (H(t)-iΔz) at the current time, i=1, 2,…,N.

[0145] It should be noted that, due to the fact that the slag soil in the sealing cabin is supplemented by the front stratum and transported by the screw conveyor during the tunneling process, the area of the gas pressure action may change, and therefore, it is necessary to determine the volume rate v 土层，进入 of the soil layer entering the sealing cabin. 土层，输走 The volume rate v 土层，输走 of the slag soil transported out of the sealing cabin by the screw conveyor and the volume rate v 土层，进入 of the stratum entering the sealing cabin during the tunneling process determine the slag soil transportation efficiency v 土层，进入 .

[0146] The volume rate v 推进 of the soil layer entering the sealing cabin during the tunneling process is determined by the tunneling speed v 土层，输走 and the diameter D of the cutter head.

[0147]

[0148] The slag soil transportation efficiency v s during the tunneling process is determined by the model of the screw conveyor (pitch l, effective soil discharge area A 螺旋机转速 ), the soil discharge efficiency (related to the improved slag soil) η, and the rotation speed ω 螺旋机转速 of the screw conveyor:

[0149]

[0150] η represents the soil discharge efficiency of the shield machine, ω 螺旋机转速 (t) represents the rotation speed of the screw conveyor of the shield machine at the current time, A s represents the effective soil discharge area of the screw conveyor of the shield machine, l represents the pitch of the screw conveyor of the shield machine, and v 推进 (t) represents the tunneling speed of the shield machine at the current time.

[0151] Affected by the tunneling speed and the rotation speed of the screw conveyor, the interface of the soil layer in the sealing cabin fluctuates, and the change increment of the pressure action area of the air cabin is:

[0152]

[0153] The change of the interface height in the sealing cabin is:

[0154]

[0155] From the above S(t+Δt), H(t+Δt), the precise control of the supporting force of the sealing cabin can be realized by adjusting the screw rotation speed and the tunneling speed of the shield machine.

[0156] In the actual shield tunneling process, the air pressure is not continuously controlled, but after losing a certain amount, it is pressurized to the specified value again, so the precise calculation of the air pressure loss q(t) helps to determine the time of pressure compensation. The air pressure loss q(t) includes the flow into the stratum q1(t) and the flow into the soil pore in the sealing cabin q2(t).

[0157] Specifically, after calculating the supporting force of the sealing cabin at the current time, the air pressure loss in the sealing cabin at the current time can be determined according to the gas infiltration theory through the following steps, and the supporting force F 密封舱 (t+Δt) of the sealing cabin at the next time can be obtained according to the supporting force F 密封舱 (t) of the sealing cabin at the current time and the air pressure loss q(t) in the sealing cabin at the current time:

[0158] The soil-gas layer interface height H(t+Δt) in the sealing cabin at the next time is calculated by the formula

[0159] The shield sealing cabin air pressure P (t+Δt) at the next time is calculated by the formula

[0160] The air pressure loss q(t) in the sealing cabin at the current time is calculated by the formula q(t)=q1(t)+q2(t);

[0161] The gas flow into the stratum q1(t) and the stratum gas permeation coefficient k sq1 are related to:

[0162] P 标态 q1(t+Δt)=P 标态 q1(t)+P 标态 k sq1 i 地层 S(t)Δt

[0163] The gas flow into the soil pore in the sealing cabin q 2( t) is:

[0164]

[0165] The soil-gas mixed pressure resultant force F 密封舱 (t+Δt) of the sealing cabin at the next time is calculated by the formula:

[0166]

[0167] ​Wherein, t represents the current time, Δt represents the time difference between the next time and the current time, q1(t) represents the current time cumulative inflow gas amount, q2(t) represents the current time cumulative inflow gas amount in the soil pore of the sealed cabin, q1(t+Δt) represents the next time cumulative inflow gas amount, k sq1 represents the gas permeability coefficient of the stratum, h represents the cutter top depth of the shield machine, q2(t+Δt) represents the next time cumulative inflow gas amount in the soil pore of the sealed cabin, k sq2 represents the gas permeability coefficient of the soil.

[0168] It should be noted that, in the calculation of i 渣土 , since the spiral conveyor position soil movement is mainly along with the transmission belt linkage movement, at this time the gas permeation can be ignored, so the seepage path l=H, the head difference can be approximated as P-P 标态 , considering unit conversion, we get

[0169] Step 16, obtaining the active soil pressure resultant force and passive soil pressure resultant force of the stratum.

[0170] Specifically, the calculation formula of the active soil pressure resultant force F 主动土压力 of the stratum is:

[0171]

[0172] Wherein, F 主动土压力 represents the active soil pressure resultant force of the stratum, k 主动 represents the active soil pressure coefficient, represents the internal friction angle of the tunneling stratum, γ i represents the specific weight of the i-th layer of soil of the tunneling stratum, h represents the cutter top depth of the shield machine, h i represents the top height of the i-th layer of soil, c i represents the cohesion of the i-th layer of soil of the tunneling stratum.

[0173] The calculation formula of the passive soil pressure resultant force F 被动土压力 of the stratum is:

[0174]

[0175] Wherein, F 被动土压力 represents the passive soil pressure resultant force of the stratum, k 被动 represents the passive soil pressure coefficient,

[0176] Step 17, adjust the tunneling speed of the shield machine and the rotation speed of the screw machine to make the combined force of the air-soil mixture pressure in the soil cabin between the combined force of the active soil pressure and the passive soil pressure of the stratum in front of the excavation face, so as to ensure the stability of the tunneling stratum.

[0177] In some embodiments of the present application, the above-mentioned condition for ensuring the stability of the tunneling stratum can be understood as a stratum force balance condition, which is: 主动土压力 ≤F 密封舱 (t+Δt)≤F 被动土压力 , H min ≤H(t+Δt)≤H max .

[0178] Wherein, H min represents the preset minimum sealing cabin soil-air layer interface height, and H max represents the preset maximum sealing cabin soil-air layer interface height.

[0179] As Figure 3 shown, the specific implementation of adjusting the tunneling speed of the shield machine and the rotation speed of the screw machine is:

[0180] If F 密封舱 (t+Δt)<F 主动土压力 , reduce the tunneling speed of the shield machine, increase the rotation speed of the screw machine of the shield machine and the air pressure of the shield sealing cabin;

[0181] If F 密封舱 (t+Δt)>F 被动土压力 , increase the tunneling speed of the shield machine, reduce the rotation speed of the screw machine of the shield machine and the air pressure of the shield sealing cabin;

[0182] If H(t+Δt)>H max , reduce the tunneling speed of the shield machine and increase the rotation speed of the screw machine of the shield machine;

[0183] If H(t+Δt)<H min , increase the tunneling speed of the shield machine and reduce the rotation speed of the screw machine of the shield machine.

[0184] It can be understood that the above adjustment means that at the next time, the value at the current time is appropriately adjusted, for example, based on the air pressure of the shield sealing cabin at the current time, the air pressure is appropriately increased to 5-6 atmospheres.

[0185] Since the pressurization process is not continuous, the above adjustment is periodically performed, in order to maintain the stability of the tunneling interface, the air pressure P(t) of the shield sealing cabin at the current time can be calculated by the following formula:

[0186]

[0187] Specifically, if the air pressure change amount P(t) is greater than the air pressure change threshold, the shield cabin air pressure is increased.

[0188] Wherein, t0 represents the time of the last air pressure supplement, S(t0+jΔt) represents the air cabin acting area of the jth time interval divided by Δt from t0 to t in the refined solution, and H(t0+jΔt) represents the soil layer interface height of the jth time interval divided by Δt from t0 to t.

[0189] It should be noted that if the next time the ground active soil pressure, the ground passive soil pressure and the supporting force of the sealing cabin meet the ground force balance condition, the tunneling speed, the screw speed and the shield cabin air pressure do not need to be adjusted, and the current time parameters can be used as the recommended tunneling parameters.

[0190] In summary, as shown in Figure 4 When calculating the supporting force (i.e., effective supporting force) of the air pressure assisted shield cabin, the present application comprehensively considers the three-phase, ideal gas state balance equation of the tunneling stratum, the experience formula for improved muck, the seepage force, the resistance of the sealing cabin wall to the muck, and the vertical stress physical differential equation; when calculating the air pressure loss of the air pressure assisted shield, the gas infiltration into the muck and the stratum is considered, which realizes more accurate calculation of air pressure and more scientific determination of air pressure supplement time.

[0191] Most of the parameters in the mathematical model proposed in the present application are based on physical models, rather than estimated by machine learning, so the model still has certain persuasiveness in strata with less tunneling data.

[0192] It is worth mentioning that the present application comprehensively considers the multi-factors of gas and liquid infiltration, muck migration, tunneling speed, screw speed and other tunneling parameters to construct a sealing cabin pressure distribution physical model, realizes accurate calculation of the mixed pressure of the sealing cabin from the essence of the stress state change of the muck in the sealing cabin, the seepage force of the seepage field to the muck and the resistance of the sealing cabin wall to the muck, so as to accurately detect whether the ground force meets the ground force balance condition, and timely adjust the tunneling speed and screw speed of the shield machine when the ground force balance condition is not met, thereby realizing accurate control of the supporting force of the sealing cabin and improving the control accuracy of the supporting force of the sealing cabin.

[0193] That is, the application provides a sealing cabin pressure distribution physical model considering multiple factors of tunneling parameters such as stratum properties, tunneling speed, screw rotation speed, and sealing cabin air pressure. Under the dynamic actions of "gas infiltration", "underground water seepage", and "muck transport", the increase of gas moles in the muck pores in the sealing cabin caused by gas infiltration is considered, and then the muck pore air pressure and excess pore water pressure are increased. From the essence of the stress state change of the muck in the sealing cabin, and considering the seepage force of the seepage field on the muck and the resistance of the sealing cabin wall to the muck, the gas-soil mixed pressure in the sealing cabin is accurately calculated.

[0194] The above is the preferred embodiment of the application. It should be pointed out that for ordinary skilled persons in the technical field, several improvements and refinements can be made without departing from the principles described in the application, and these improvements and refinements should also be considered as the protection scope of the application.

Claims

1. A method for controlling the pressure in a shield soil chamber in a pneumatic auxiliary excavation mode, characterized by The method comprises the following steps: obtaining the changes of the gas, solid and liquid three-phase volume percentages of the slag, the pore water pressure and the pore gas pressure, considering the compressibility and unsaturated characteristics of the foam improved slag, obtaining the friction between the slag in the sealed cabin and the cabin wall shell, the penetration force of the slag and the self-weight of the slag at the current time; the sealed cabin is a sealed cabin of a shield machine, and the penetration force is caused by the infiltration of water and gas into the slag; based on the force balance of the slag in the sealed cabin, a vertical effective stress distribution balance equation of the foam improved slag in the soil cabin is established according to the friction between the slag in the sealed cabin and the cabin wall shell, the penetration force and the self-weight of the slag; determining the current air-soil mixed pressure resultant force in the soil cabin according to the established vertical effective stress distribution of the foam improved slag in the soil cabin and the height of the air-soil interface in the soil cabin at the current time; determining the current air pressure loss in the sealed cabin according to the gas permeation characteristics test of the unsaturated soil body and the measured gas permeation coefficient of the stratum and the foam improved soil; obtaining the air-soil mixed pressure resultant force of the sealed cabin at the next time according to the rotation speed of the screw conveyor on the construction site, the tunneling speed of the shield machine, the air-soil mixed pressure of the sealed cabin at the current time and the air pressure loss in the sealed cabin; obtaining the active soil pressure resultant force and the passive soil pressure resultant force of the stratum; adjusting the tunneling speed of the shield machine and the rotation speed of the screw machine to make the air-soil mixed pressure resultant force in the soil cabin between the active soil pressure resultant force and the passive soil pressure resultant force of the stratum in front of the excavation face, so as to ensure the stability of the tunneling stratum.

2. The control method according to claim 1, characterized by, The calculation formula of the groundwater penetration force is: wherein F1 represents the groundwater permeability, γ w represents the specific weight of water, i 渣土 represents the hydraulic gradient when water infiltrates into the slag soil, P represents the air pressure in the shield cabin, P 标态 represents the standard atmospheric pressure, H represents the height of the interface between the soil gas layer in the shield cabin, B represents the length of the shield cabin, D represents the diameter of the cutter head of the shield machine, z represents the height of the slag soil from the bottom of the shield cabin, and Δz represents the average thickness of the vertical direction layering of the slag soil when discrete solving is performed. The calculation formula of the gas penetration force is: P(z) = 10(P 标态 + i 渣土 z) wherein F2represents a gas permeation force received by the soil, P(z) is an average pressure of z height pore gas converted into Pa after mm water column, φ 等效固相，渣土 (z) represents a volume percentage of the soil solid phase at position z in the sealed cabin when the compressibility of the improved soil is considered, φ 等效液相，渣土 (z) represents a volume percentage of the soil liquid phase at position z in the sealed cabin when the compressibility of the improved soil is considered, u 地层 represents a pore water pressure, ρ represents a density of the soil, ω represents a water content of the soil, G s represents a particle relative density of the soil, u(z) represents a pore water, gas pressure; The calculation formula of the friction between the slag in the sealed cabin and the cabin wall shell is: wherein, F3 represents the friction, μ represents the friction coefficient between the slag and the cabin wall shell, σ z (z) = u(z) + σ' z (z) = f(u(z)) u(z) represents pore water, gas pressure, σ' z (z) represents vertical effective stress, σ z (z) represents the vertical stress of the slurry in the sealed cabin at the current moment, f represents σ z (z) and the relationship between u(z), u w (z) pore water pressure, P(z) represents pore gas pressure; The calculation formula of the self-weight of the slag is: wherein F4 represents the self-weight, G s represents the relative density of the slag particles.

3. The control method according to claim 1, characterized by, The method for establishing the vertical effective stress distribution balance equation of the foam improved slag in the soil cabin according to the friction between the slag in the sealed cabin and the cabin wall shell, the penetration force and the self-weight of the slag based on the force balance of the slag in the sealed cabin comprises: constructing a relational expression based on the movement of the overall slag in the sealed cabin: Based on the relationship, φ 等效固相，渣土 (z) of the expression, φ 等效液相，渣土 (z) of the expression, σ z (z) = f(u(z)) for the vertical effective stress, the vertical stress σ z (z) of the sealing cabin at the current moment.

4. The control method according to claim 3, characterized by, The air-soil mixed pressure resultant force of the sealed cabin at the current time t is: wherein F 密封舱 (t) represents the current moment of the sealing cabin gas pressure force, P(t) S(t) represents the current moment of the sealing cabin gas pressure, represents the current moment of the sealing cabin gas pressure, P(t) represents the current moment of the sealing cabin gas pressure, S(t) represents the current moment of the sealing cabin gas pressure, H(t) represents the height of the interface between the soil and the gas layer in the cabin at the current time, N represents the number of layers divided when the slag layer is solved discretely, σ z (H(t)-iΔz) represents the vertical stress at the position of (H(t)-iΔz) at the current time, i=1, 2,..., N; v 土层，输走 V (t) is the volume rate of the muck transported out of the chamber by the screw conveyor, η represents the muck removal efficiency of the shield machine, ω 螺旋机转速 (t) represents the current screw conveyor speed of the shield machine, A s represents the effective muck removal area of the screw conveyor of the shield machine, and l represents the screw pitch of the screw conveyor of the shield machine; v 土层，进入 V (t) is the volume rate of the muck transported out of the chamber by the screw conveyor, v 推进 (t) represents the current tunneling speed of the shield machine; 5. The control method according to claim 4, characterized by determining the current air pressure loss in the sealed cabin according to the gas permeation characteristics test of the unsaturated soil body and the measured gas permeation coefficient of the stratum and the foam improved soil, and obtaining the air-soil mixed pressure resultant force of the sealed cabin at the next time according to the rotation speed of the screw conveyor on the construction site, the tunneling speed of the shield machine, the air-soil mixed pressure of the sealed cabin at the current time and the air pressure loss in the sealed cabin, comprising: The height H(t+Δt) of the gas-oil layer interface in the sealed cabin at the next time is calculated by the formula H(t+Δt)=H(t)-K(t)·Δt The next time shield cabin air pressure P (t + dt) is calculated by the formula ​ calculating the current air pressure loss q(t) in the sealed cabin by the formula q(t)=q1(t)+q2(t); P 标态 q1(t+Δt) = P 标态 q1(t) + P 标态 k sq1 i 地层 S(t)Δt The resultant force F of the air-earth pressure of the sealed cabin at the next time is calculated by the following equation 密封舱 (t+Δt): wherein t represents a current time, Δt represents a time difference between a next time and the current time, q1(t) represents a cumulative inflow gas amount into a formation at the current time, q2(t) represents a cumulative inflow gas amount into a soil pore in a sealed cabin at the current time, q1(t+Δt) represents a cumulative inflow gas amount into the formation at the next time, k sq1 represents a gas permeability coefficient of the formation, h represents a cutter head top depth of the shield machine, q2(t+Δt) represents a cumulative inflow gas amount into the soil pore in the sealed cabin at the next time, k sq2 represents a gas permeability coefficient of the soil.

6. The control method according to claim 5, characterized by The calculation formula of the active soil pressure resultant force of the stratum is: wherein F 主动土压力 represents the resultant of the active earth pressure of the strata, k 主动 represents the active earth pressure coefficient, represents the internal friction angle of the strata being excavated, γi represents the specific gravity of the i-th layer of soil of the strata being excavated, h represents the depth of the top of the cutter head of the shield machine, hi i represents the height of the top of the i-th layer of soil, c i represents the cohesion of the i-th layer of soil of the strata being excavated.

7. The control method according to claim 6, characterized by The calculation formula of the passive soil pressure resultant force of the stratum is: where F 被动土压力 represents the resultant passive earth pressure of the stratum, k 被动 represents the passive earth pressure coefficient, 8. The control method according to claim 7, characterized by F 主动土压力 ≤F 密封舱 (t+Δt)≤F 被动土压力 , H min ≤H(t+Δt)≤H max ; H min represents a preset minimum sealed cabin inner soil gas layer interface height, H max represents a preset maximum sealed cabin inner soil gas layer interface height.

9. The control method according to claim 8, characterized by, adjusting the tunneling speed of the shield machine and the rotation speed of the screw machine, comprising: If F 密封舱 (t+Δt)<F 主动土压力 then reduce the tunneling speed of the tunneling machine, increase the screw rotation speed of the tunneling machine and the air pressure in the shield cabin. If F 密封舱 (t+Δt)>F 被动土压力 , then increase the tunneling speed of the shield machine, reduce the screw rotation speed of the shield machine and the air pressure of the shield sealing cabin; If H(t+Δt)>H max then decrease the tunneling speed of the shield machine and increase the screw rotating speed of the shield machine; If H(t+Δt) < H min then increase the tunneling speed of the shield machine and decrease the screw rotation speed of the shield machine.

10. The control method according to claim 9, characterized by The control method further comprises: calculating the air pressure P(t) of the shield sealed cabin at the current time by the following formula: In the formula, t0 represents the time of the last air pressure supplement, S(t0+jΔt) represents the air chamber acting area of the jth time interval divided by Δt from t0 to t in the refined solution, and H(t0+jΔt) represents the soil layer interface height of the jth time interval divided by Δt from t0 to t. In the formula, t0 represents the time of the last air pressure supplement, S(t0+jΔt) represents the air chamber acting area of the jth time interval divided by Δt from t0 to t in the refined solution, and H(t0+jΔt) represents the soil layer interface height of the jth time interval divided by Δt from t0 to t.

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