A construction method for coordinated operation of a dual-mode shield tunneling machine in a gravel-mudstone composite stratum

Abstract

The present invention discloses a construction method for cooperative operation of a dual-mode shield in a gravel-mudstone composite stratum, which comprises the following steps: dividing the shield tunneling section into a gravel stratum section and a mudstone stratum section according to geological exploration, and planning the shield tunneling mode according to the formation permeability of the gravel stratum section and the mudstone stratum section; respectively calculating the shield lengths L of the gravel stratum section and the mudstone stratum section, and calculating the tunneling time T in the gravel stratum section and the mudstone stratum section according to the shield lengths s ; using the slurry generated by the two shield methods to balance the water and soil pressure in front of the working face. By reasonably adjusting the tunneling progress of the dual-mode shield and the shield in the adjacent section, the present invention can achieve that there is no need to treat the slurry generated during the tunneling of the shield in the mudstone stratum, reducing the slurry treatment cost and the cost of transporting the mud residue; there is no need to prepare the slurry required for the shield to tunnel in the gravel stratum, reducing the slurry preparation cost.

Description

Technical Field

[0001] The present invention relates to the technical field of shield construction, and particularly relates to a construction method for the coordinated operation of a dual-mode shield in a gravel-mudstone composite stratum. Background Art

[0002] The shield method is generally used for the construction of subway sections. Shield construction has the advantages of fast construction speed, small disturbance to the surrounding environment, and high construction safety. Therefore, the shield construction technology is applied more and more widely. However, many problems still occur in the preparation and treatment of slurry during shield tunneling, such as high cost and long treatment time in slurry preparation and treatment.

[0003] Currently, during the construction of dual-mode shield tunneling, the treatment and preparation of shield slurry are considered independently and separately, and the treatment and preparation of slurry are not fully considered as a whole. Therefore, it is necessary to invent a construction method for the coordinated operation of a dual-mode shield in a gravel-mudstone composite stratum. Summary of the Invention

[0004] In view of the above deficiencies of the prior art, the present invention provides a construction method for the coordinated operation of a dual-mode shield in a gravel-mudstone composite stratum, which can make full use of the slurry generated during shield tunneling, accelerate the shield tunneling speed, and reduce the construction cost of shield tunneling.

[0005] To achieve the above invention objective, the technical solution adopted by the present invention is as follows:

[0006] Provide a construction method for the coordinated operation of a dual-mode shield in a gravel-mudstone composite stratum, which includes the following steps:

[0007] Divide the shield tunneling section into a gravel stratum section and a mudstone stratum section according to geological exploration, and plan the shield tunneling mode according to the formation permeability of the gravel stratum section and the mudstone stratum section;

[0008] Calculate the shield lengths L of the gravel stratum section and the mudstone stratum section respectively, and calculate the tunneling time T in the gravel stratum section and the mudstone stratum section according to the shield lengths; s ;

[0009] When the dual-mode shield tunnels in the mudstone stratum in the earth pressure balance mode, make the dual-mode shield using the slurry balance mode tunnel staggeredly in the gravel stratum, and the tunneling progress of the earth pressure balance mode lags behind the tunneling progress of the slurry balance mode by a length of s; within the length s, the slurry generated during the tunneling of the dual-mode shield in the mudstone stratum is transported to the dual-mode shield using the slurry balance mode through the slurry circulation system, and is used to balance the water and soil pressure in front of the working face during the tunneling of the dual-mode shield in the gravel stratum;

[0010] When a dual-mode shield tunneling machine operating in the slurry balance mode is tunneling in a gravel stratum, a dual-mode shield tunneling machine operating in the earth pressure balance mode is used to tunnel in a mudstone stratum; the slurry generated during the tunneling of the dual-mode shield in the mudstone stratum is transported to the shield operating in the slurry balance mode through a slurry circulation system for balancing the water and soil pressure in front of the working face during tunneling in the gravel stratum;

[0011] Further, the method for balancing the water and soil pressure in front of the working face is as follows:

[0012] Calculate the total volume V of the slurry generated during the tunneling of the dual-mode shield in the mudstone stratum R :

[0013] V R =(1 - ω)ρπR 2 L - V A

[0014] where ω is the loss coefficient, representing the slurry precipitated and lost in the pipeline and slurry storage equipment; ρ is the slurry conversion rate, representing the volume of slurry that can be converted from a unit volume of muck; R is the radius of the shield cutterhead; L is the length of the mudstone construction section; V A is the volume of slurry that needs to be consumed by itself during the tunneling of the slurry shield or dual-mode shield;

[0015] Reasonably allocate the volume V of the slurry transported to the front of the working face according to the water and soil pressure P in front of the working face to be balanced B ;

[0016] Compare the total volume V R with the volume V B . If V R ≥V B , the slurry circulation system transports the slurry with a volume of V B to the front of the working face to balance the water and soil pressure, and the remaining slurry is discharged from the slurry circulation system;

[0017] If V R <V B , the slurry circulation system transports the slurry with a volume of V R to the front of the working face, and prepares the slurry with a volume of V B -V R and discharges it into the slurry circulation system.

[0018] Further, the calculation method of the tunneling time T s is as follows:

[0019] T s =L / v + t a +t s

[0020] where v is the tunneling speed of the earth pressure balance shield or dual-mode shield, and t aThe time required for the assembly of shield segments, t s The time required for the maintenance of the shield machine during shutdown;

[0021] For a shield machine using the slurry balance mode at the start of tunneling, the length lagging behind a shield machine using the earth pressure balance mode in the mudstone formation should be such that after this section of the mudstone formation is excavated by the dual-mode shield machine, the volume of slurry generated is greater than the slurry volume required for the excavation and assembly of three segments by the slurry shield machine;

[0022] During tunneling, the tunneling progress of a shield machine using the slurry balance mode in the cobble formation lags behind that of the shield machine in the mudstone formation, that is, ensuring that the time T S1 used to complete one cycle of excavation and segment assembly is less than or equal to the time T for the dual-mode shield machine to complete one cycle in the mudstone formation S2 ;

[0023] When the slurry storage volume is greater than the slurry volume required for the excavation and assembly of five segments by the dual-mode shield machine using the slurry balance mode, increase the tunneling speed of the shield machine in the conglomerate formation so that it exceeds the tunneling speed of the shield machine in the mudstone formation until the slurry storage volume is reduced to the amount used for the excavation and assembly of three segments.

[0024] Furthermore, the specific method for planning the tunneling mode of the shield machine according to the formation permeability is as follows:

[0025] When the permeability coefficient of the cobble formation or the mudstone formation is less than 10 -7 m / s, use the dual-mode shield machine for tunneling; when the formation permeability coefficient is greater than 10 -4 m / s, use the slurry shield machine for tunneling; otherwise, use a combination of the dual-mode shield machine and the slurry shield machine for tunneling.

[0026] Furthermore, the calculation method for the volume V B is as follows:

[0027] The shield machine using the slurry balance mode balances the water and soil pressure P on the working face through the concentration and volume of the slurry;

[0028] When the water and soil pressure on the working face increases, the volume of the slurry in the slurry chamber should be increased, and more slurry is added within a limited volume, which will generate a greater slurry pressure;

[0029] At the same time, when the slurry pressure is greater than the water and soil pressure P, the slurry in the slurry chamber will penetrate into the formation and fill the pores of the rock mass in the formation to form a mud film to prevent the infiltration of groundwater;

[0030] The volume of the slurry in the slurry chamber will continuously decrease during the tunneling of the shield machine, that is, the slurry loss; as the thickness of the mud film increases, its ability to resist the underground water and soil pressure also increases;

[0031] Then the required volume V BThe calculation formula is as follows:

[0032] V B = αV S + μπRt 2 t

[0033] Where V S is the volume of the slurry chamber, α is the volume magnification factor, μ is the formation permeability coefficient, t is the tunneling time, and R is the radius of the shield cutter head.

[0034] The beneficial effects of the present invention are as follows:

[0035] By reasonably adjusting the tunneling progress of the double-mode shield and the adjacent section shield, the present invention can achieve the effect of not having to treat the slurry generated during the tunneling of the shield in the mudstone formation, reducing the slurry treatment cost and the cost of transporting the mud residue; and not having to prepare the slurry required for the shield to tunnel in the cobble formation, reducing the slurry preparation cost.

[0036] Aiming at the deficiencies in the mutual utilization of slurry treatment and slurry preparation of the existing double-mode shield, the present invention effectively solves the problems of slurry treatment and slurry preparation during the tunneling of the double-mode shield in the cobble-mudstone composite formation, speeds up the shield tunneling speed, has a simple principle and strong implementability, reduces the shield tunneling construction cost, and has obvious economic effects.

[0037] In the present invention, the lengths of the construction sections in the conglomerate formation and the mudstone formation are calculated respectively, and the time required for the shield to tunnel in the two formations is predicted. When the slurry shield tunnels in the mudstone formation, it is ensured that the double-mode shield excavates in a staggered manner in the cobble formation, and the propulsion rate of the double-mode shield is reasonably controlled to make the two types of shields complete tunneling synchronously as much as possible. At this time, the slurry with a relatively large specific gravity generated during the tunneling of the slurry shield in the mudstone formation is required by the double-mode shield during tunneling in the cobble formation to balance the water and soil pressure in front of the working face. The slurry generated during the tunneling of the slurry shield in the mudstone formation does not need to be treated, and through the slurry circulation system, this part of the slurry can be directly used for the tunneling work of the double-mode shield in the cobble formation. By reasonably controlling the shield tunneling plan, the slurry can be reused. There is no need to prepare a large amount of slurry required for the double-mode shield to tunnel in the cobble formation, significantly saving the construction cost. If the amount of slurry generated during the tunneling of the slurry shield is insufficient, it can be appropriately supplemented by on-site preparation.

[0038] When the slurry shield is tunneling in the cobble stratum, the dual-mode shield is tunneling in the mudstone stratum. At this time, the dual-mode shield generates slurry with a relatively large specific gravity when tunneling in the mudstone stratum. The slurry shield needs slurry with a relatively large specific gravity to balance the water and soil pressure of the face when tunneling in the cobble stratum. The slurry generated by the dual-mode shield when tunneling in the mudstone stratum does not need to be treated. Through the slurry circulation system, this part of the slurry can be directly used for the tunneling work of the slurry shield in the cobble stratum. It is not necessary to treat the slurry generated by the dual-mode shield when tunneling in the mudstone stratum, and the slurry required for the slurry shield to tunnel in the cobble stratum can be significantly reduced. Description of the Drawings

[0039] Figure 1 It is a flow chart of the construction method of the dual-mode shield for the cobble-mudstone composite stratum. Detailed Embodiments

[0040] The following describes the detailed embodiments of the present invention to facilitate those skilled in the art to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the detailed embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions made using the concept of the present invention are within the scope of protection.

[0041] As Figure 1 shown, the construction method of the dual-mode shield for the cobble-mudstone composite stratum of this solution includes the following steps:

[0042] According to geological exploration, the shield tunneling section is divided into a cobble stratum section and a mudstone stratum section, and the tunneling mode of the shield is planned according to the formation permeability of the cobble stratum section and the mudstone stratum section; the specific method for planning the tunneling mode of the shield according to the formation permeability is:

[0043] When the permeability coefficient of the cobble stratum or the mudstone stratum is less than 10 -7 m / s, use the dual-mode shield for tunneling; when the formation permeability coefficient is greater than 10 -4 m / s, use the slurry shield for tunneling; otherwise, use a combination of the dual-mode shield and the slurry shield for tunneling.

[0044] Calculate the shield lengths L of the cobble stratum section and the mudstone stratum section respectively, and calculate the tunneling time T in the cobble stratum section and the mudstone stratum section according to the shield length s ; the calculation method of the tunneling time T s is:

[0045] T s = L / v + t a + t s

[0046] Among them, v is the tunneling speed of the earth pressure balance shield or the dual-mode shield, and t a is the time required for the assembly of the shield segments, and t s is the time required for the shield to stop for maintenance;

[0047] For the shield that adopts the slurry balance mode at the beginning of tunneling, the length lagging behind the shield that adopts the earth pressure balance mode in the mudstone formation should be such that after the mudstone formation in this section is completely tunneled by the dual-mode shield, the volume of the slurry generated is greater than the slurry volume required for the slurry shield to excavate and assemble three segments;

[0048] During tunneling, the tunneling progress of the shield that adopts the slurry balance mode in the cobble formation lags behind that of the shield in the mudstone formation, that is, to ensure that the time T S1 used to complete one cycle of excavation and segment assembly is less than or equal to the time T S2 for the dual-mode shield to complete one cycle in the mudstone formation;

[0049] When the slurry storage volume is greater than the slurry volume required for the dual-mode shield with the slurry balance mode to tunnel and assemble five rings of segments, increase the tunneling speed of the shield in the conglomerate formation so that it exceeds the tunneling speed of the shield in the mudstone formation until the slurry storage volume is reduced to the amount used for excavating and assembling three rings of segments.

[0050] When the dual-mode shield adopts the earth pressure balance mode to tunnel in the mudstone formation, make the dual-mode shield with the slurry balance mode tunnel staggeredly in the cobble formation, and the tunneling progress of the earth pressure balance mode lags behind that of the slurry balance mode by a length of s; within the length s, the slurry generated when the dual-mode shield tunnels in the mudstone formation is transported to the dual-mode shield with the slurry balance mode through the slurry circulation system to balance the water and soil pressure in front of the working face during tunneling in the cobble formation by the dual-mode shield;

[0051] When the dual-mode shield with the slurry balance mode tunnels in the cobble formation, the dual-mode shield with the earth pressure balance mode tunnels in the mudstone formation; the slurry generated when the dual-mode shield tunnels in the mudstone formation is transported to the shield with the slurry balance mode through the slurry circulation system to balance the water and soil pressure in front of the working face during tunneling in the cobble formation;

[0052] The method for balancing the water and soil pressure in front of the working face is as follows:

[0053] Calculate the total volume V R of the slurry generated when the dual-mode shield tunnels in the mudstone formation:

[0054] V R =(1 - ω)ρπR 2 L - V A

[0055] Among them, ω is the loss coefficient, representing the mud precipitated and lost in the pipeline and mud storage equipment; ρ is the mud conversion rate, representing the volume of mud that can be converted from unit muck; R is the radius of the shield cutter head; L is the length of the mudstone construction section; V A is the volume of mud that needs to be consumed by the slurry shield or double-mode shield during tunneling;

[0056] According to the water and soil pressure P in front of the working face, the volume V of mud transported to the front of the working face is reasonably distributed B ; the volume V B is calculated as follows:

[0057] The slurry shield adopting the slurry balance mode balances the water and soil pressure P of the working face through the concentration and volume of the slurry;

[0058] When the water and soil pressure of the working face increases, the volume of slurry in the slurry chamber should be increased, and more slurry is added within a limited volume, which will generate a greater slurry pressure;

[0059] At the same time, when the slurry pressure is greater than the water and soil pressure P, the slurry in the slurry chamber will penetrate into the formation and fill the pores of the rock mass in the formation to form a mud film to prevent the penetration of groundwater;

[0060] The volume of slurry in the slurry chamber will continuously lose with the tunneling of the shield, that is, the slurry loss; as the thickness of the mud film increases continuously, its ability to resist the underground water and soil pressure also increases;

[0061] Then the required volume V B is calculated as follows:

[0062] V B = αV S + μπRt 2 t

[0063] In the formula, V S is the volume of the slurry chamber, α is the volume magnification coefficient, μ is the formation permeability coefficient, t is the tunneling time, and R is the radius of the shield cutter head.

[0064] Compare the total volume V R with the volume V B , if V R ≥ V B , the slurry circulation system transports the slurry with volume V B to the front of the working face to balance the water and soil pressure, and the remaining slurry is discharged from the slurry circulation system;

[0065] If V R < V B , the slurry circulation system transports the slurry with volume V R to the front of the working face and prepares V B-V R The slurry with a certain volume is discharged into the slurry circulation system.

[0066] By reasonably adjusting the tunneling progress of the dual-mode shield and the adjacent section shield, the present invention can achieve that there is no need to treat the slurry generated during the tunneling of the shield in the mudstone formation, reducing the slurry treatment cost and the cost of transporting the mud residue; there is no need to prepare the slurry required for the shield to tunnel in the cobble formation, reducing the slurry preparation cost.

[0067] Aiming at the deficiencies in the mutual utilization of slurry treatment and slurry preparation in the existing dual-mode shield, the present invention effectively solves the problems of slurry treatment and slurry preparation when the dual-mode shield tunnels in the cobble-mudstone composite formation, speeds up the shield tunneling speed, has a simple principle and strong implementability, reduces the shield tunneling construction cost, and has obvious economic effects.

[0068] In the present invention, the lengths of the construction sections in the conglomerate formation and the mudstone formation are calculated respectively, and the time required for the shield to tunnel in the two formations is predicted. When the slurry shield tunnels in the mudstone formation, it is ensured that the dual-mode shield excavates in a staggered manner in the cobble formation, and the propulsion rate of the dual-mode shield is reasonably controlled to make the two types of shields complete tunneling synchronously as much as possible. At this time, the slurry with a relatively large specific gravity generated when the slurry shield tunnels in the mudstone formation is needed by the dual-mode shield to balance the water and soil pressure in front of the working face when tunneling in the cobble formation. The slurry generated when the slurry shield tunnels in the mudstone formation does not need to be treated. Through the slurry circulation system, this part of the slurry can be directly used for the tunneling work of the dual-mode shield in the cobble formation. By reasonably controlling the shield tunneling plan, the slurry can be reused. There is no need to prepare a large amount of slurry required for the dual-mode shield to tunnel in the cobble formation, significantly saving the construction cost. If the amount of slurry generated during the tunneling of the slurry shield is insufficient, it can be appropriately supplemented by on-site preparation.

[0069] When the slurry shield tunnels in the cobble formation, the dual-mode shield tunnels in the mudstone formation. At this time, the slurry with a relatively large specific gravity generated when the dual-mode shield tunnels in the mudstone formation is needed by the slurry shield to balance the water and soil pressure of the working face when tunneling in the cobble formation. The slurry generated when the dual-mode shield tunnels in the mudstone formation does not need to be treated. Through the slurry circulation system, this part of the slurry can be directly used for the tunneling work of the slurry shield in the cobble formation. It is possible to avoid treating the slurry generated when the dual-mode shield tunnels in the mudstone formation and significantly reduce the preparation of the slurry required for the slurry shield to tunnel in the cobble formation.

Claims

1. A construction method for combined operation of a dual-mode shield tunneling machine in a gravel-mudstone composite stratum, characterized in that, It includes the following steps: According to geological exploration, the shield tunneling section is divided into a cobble stratum section and a mudstone stratum section, and the shield tunneling mode is planned according to the stratum permeability of the cobble stratum section and the mudstone stratum section; Calculate the shield lengths L in the gravel stratum section and the mudstone stratum section respectively, and calculate the tunneling times T in the gravel stratum section and the mudstone stratum section according to the shield lengths s ; When the dual-mode shield tunneling machine uses the earth pressure balance mode to tunnel in the mudstone stratum, the dual-mode shield tunneling machine using the slurry balance mode tunnels in a staggered manner in the cobble stratum, and the tunneling progress of the earth pressure balance mode lags behind the tunneling progress of the slurry balance mode by a length of s; within the length s, the slurry generated when the dual-mode shield tunneling machine tunnels in the mudstone stratum is transported to the dual-mode shield tunneling machine using the slurry balance mode through the slurry circulation system, and is used to balance the water and soil pressure in front of the working face when the dual-mode shield tunneling machine tunnels in the cobble stratum; When the dual-mode shield tunneling machine using the slurry balance mode tunnels in the cobble stratum, the dual-mode shield tunneling machine using the earth pressure balance mode tunnels in the mudstone stratum; the slurry generated when the dual-mode shield tunneling machine tunnels in the mudstone stratum is transported to the shield tunneling machine using the slurry balance mode through the slurry circulation system, and is used to balance the water and soil pressure in front of the working face when tunneling in the cobble stratum.

2. The dual-mode shield cooperation construction method for the gravel-mudstone composite stratum according to claim 1, characterized in that, The method for balancing the water and soil pressure in front of the working face is as follows: Calculate the total volume V of the slurry generated during the tunneling of the double-mode shield in the mudstone formation R : V R =(1 - ω)ρπR 2 L - V A Among them, ω is the loss coefficient, representing the mud precipitated and lost in the pipeline and mud storage equipment; ρ is the mud conversion rate, representing the volume of mud that can be converted from unit muck; R is the radius of the shield cutter head; L is the length of the mudstone construction section; V A is the volume of mud required for the self-consumption of the slurry shield or double-mode shield during tunneling; Reasonably distribute the volume V of mud conveyed to the front of the balanced heading face according to the water and soil pressure P in front of the balanced heading face B ; Compare the total volume V R with the volume V B . If V R ≥ V B , the mud circulation system conveys the mud with a volume of V B to the front of the balance face to balance the water and soil pressure, and the remaining mud is discharged from the mud circulation system; If V R <V B , the mud circulation system conveys mud with volume V R to the front of the equilibrium heading face, and prepares mud with volume V B -V R and discharges it into the mud circulation system.

3. The construction method of dual-mode shield tunneling in the gravel-mudstone composite stratum according to claim 1, characterized in that, The tunneling time T s is calculated as follows: T s = L / v + t a + t s wherein, v is the tunneling speed of a soil shield or a dual-mode shield, t a is the time required for segment erection of the shield, t s is the time required for maintenance of the shield during shutdown; At the beginning of tunneling, the shield tunneling machine using the slurry balance mode should lag behind the shield tunneling machine using the earth pressure balance mode in the mudstone stratum by a length such that after the mudstone stratum is tunneled by the dual-mode shield tunneling machine, the volume of the generated slurry is greater than the slurry volume required for the slurry shield tunneling machine to excavate and assemble three segments; During the tunneling process, the tunneling progress of the slurry shield in the cobble stratum lags behind that in the mudstone stratum, that is, ensuring that the time T S1 used to complete one cycle of excavation and segment erection is less than or equal to the time T S2 for the double-mode shield to complete one cycle in the mudstone stratum; When the slurry storage volume is greater than the slurry volume required for the dual-mode shield tunneling machine using the slurry balance mode to tunnel and assemble five segments, the tunneling speed of the shield tunneling machine in the conglomerate stratum is increased so that it exceeds the tunneling speed of the shield tunneling machine in the mudstone stratum until the slurry storage volume is reduced to the amount used for excavating and assembling three segments.

4. The construction method of dual-mode shield tunneling in cobble-mudstone composite strata according to claim 1, characterized in that The specific method for planning the shield tunneling mode according to the stratum permeability is as follows: When the permeability coefficient of the gravel stratum or mudstone stratum is less than 10 -7 m / s, a dual-mode shield tunneling machine is used; when the permeability coefficient of the stratum is greater than 10 -4 m / s, a slurry shield tunneling machine is used; otherwise, tunneling is carried out in a combination of dual-mode shield and slurry shield.

5. The construction method of double-mode shield tunneling in gravel-mudstone composite stratum according to claim 2, characterized in that The volume V B is calculated as follows: The shield tunneling machine using the slurry balance mode balances the water and soil pressure P of the working face through the concentration and volume of the slurry; When the water and soil pressure of the working face increases, the slurry volume in the slurry chamber should be increased, and more slurry should be added within a limited volume, which will generate a greater slurry pressure; At the same time, when the slurry pressure is greater than the water and soil pressure P, the slurry in the slurry chamber will penetrate into the stratum and fill the pores of the rock mass in the stratum to form a mud film to prevent the infiltration of groundwater; The slurry volume in the slurry chamber will continuously decrease as the shield tunnels, that is, the slurry loss; as the thickness of the mud film increases, its ability to resist the underground water and soil pressure also increases; The required volume V B is calculated as follows: V B = αV S + μπR 2 t where V S is the volume of the slurry chamber, α is the volume magnification factor, μ is the formation permeability coefficient, t is the tunneling time, and R is the radius of the shield cutterhead.

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