Shield underground docking multi-stage main drive retaining design method

Abstract

The invention discloses a multi-stage main drive retaining design method for shield in-ground docking, relates to the technical field of shield tunnel engineering, and is used for performing main drive retaining reinforcement on a preceding shield during shield in-ground docking, and the shield in-ground docking is divided into two stages based on the distance between the preceding shield and a following shield. A retaining steel plate is arranged along the outer surface of the main drive in the first stage, when the left and right reaction torque oil cylinders are not disassembled, the main drive retaining steel plates of the upper semicircle and the lower semicircle are installed firstly, the main drive left and right reaction torque oil cylinders are disassembled in the second stage, the retaining steel plates continue to be arranged at the vacant positions, and theoretical support is provided for reinforcing and retaining construction of the main drive. Therefore, the safety and the stability of the advanced shield tunneling machine structure in the butt joint process are ensured. Furthermore, by designing the plane size of the main drive retaining steel plate, determining the welding seam range, determining the retreating force of the telescopic oil cylinder in the first stage and the second stage, checking and determining the thickness, the number and the distance of the retaining steel plates in the first stage and the second stage and the like, the scheme can be actually applied to the ground and is suitable for industrial popularization.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnel engineering, in particular to a shield underground docking multi-stage main drive stop design method. Background Art

[0002] In recent years, my country's infrastructure has developed rapidly. As an effective way to solve traffic problems, undersea tunnels can connect railway trunk lines and highway trunk lines in areas across the sea, thereby expanding the railway and highway transportation network and improving transportation efficiency. Undersea tunnels usually adopt underground docking and in-tunnel disintegration construction methods, which avoids the excavation of vertical shafts on the ground, shortens the construction period, and ensures the safety and quality of tunnel construction. With the continuous strengthening of my country's economic strength, there are more and more long-distance, large-diameter, deep-buried, and cross-river, sea and river tunnels. The underground docking method is one of the effective methods to improve efficiency and shorten construction periods in long-distance tunnel excavation, especially in long-distance tunnel construction across straits, rivers, mountains and rivers.

[0003] At present, during the implementation of the shield underground docking method, the advance shield is inevitably in a shutdown state. The force on the main drive of the advance shield is composed of two parts: the soil pressure of the cutterhead and the water pressure of the cutterhead disc. The force transmission path is: main drive → telescopic cylinder → longitudinal beam → shield shell. The mud and water tank is currently filled with mortar, but the filling density cannot be guaranteed. After the longitudinal beam is removed, the rear part loses support, and it cannot be guaranteed that the cutterhead and the main drive will not move backward or maintain the effectiveness of the main drive seal after moving backward a certain distance. Therefore, before the longitudinal beam is removed, the main drive must be reinforced, the force transmission path must be changed, and the safety of the main drive during the dismantling process must be ensured.

[0004] The existing similar technology patent CN117329302A "Installation device and installation method of shield main drive seal" realizes the replacement of main drive density by clamping the fixing seat on the annular main drive seal. However, this method cannot guarantee the reinforcement effect of the main drive and has certain limitations.

[0005] Although a lot of work has been done in existing public research, the following technical problems have not been completely solved:

[0006] 1. Before the underground docking process, the advance shield machine is shut down for a long time. When the pressure on the face is unstable, it is impossible to ensure that the main drive of the advance shield machine will not move backward.

[0007] 2. Before the main drive moves backward, how to take convenient and effective construction measures to reinforce the main drive and prevent it from moving backward.

[0008] 3. How to verify the safety and reliability of the main drive thrust reinforcement after construction. Summary of the invention

[0009] The purpose of the present invention is to address the above-mentioned problems existing in the prior art, overcome the shortcomings of the prior art, design a method for optimizing the design of the main drive reinforcement stop parameters for underground docking of shield tunnels, fully consider the difference between the retreat force of the main drive telescopic cylinder and the installation space, design the stop steel plate in stages, and determine the plane size of the stop steel plate by investigating and analyzing the main drive spatial position; clarify the reasonable range of the weld by considering the main drive seal; clarify the design basis of the main drive stop reinforcement by determining the retreat force of the main drive telescopic cylinder in the first and second stages; and optimize the stop steel plate bearing parameters by checking the strength of the stop steel plate parent material and weld. It provides theoretical support for the main drive reinforcement stop construction of large-diameter shield tunnels, solves the problems of main drive retreat and damage to the main drive seal caused by long-term shutdown of the shield machine, which endanger the safety of the shield, and ensures the safety of docking construction.

[0010] The present invention designs a multi-stage main drive backstop design method for underground docking of a shield machine: the underground docking of the shield machine is divided into two stages based on the distance between the preceding shield machine and the succeeding shield machine. In the first stage, backstop steel plates are arranged along the outer surface of the main drive. When the left and right anti-torque cylinders are not removed, the upper semi-circular arc and the lower semi-circular arc main drive backstop steel plates are installed first. In the second stage, the left and right anti-torque cylinders of the main drive are removed, and the vacated positions are used to continue to arrange the backstop steel plates.

[0011] Preferably, the anti-retreat steel plate is arranged at the intersection of the bubble cabin and the main drive. With the help of the L-shaped structure of the bubble cabin, one side of the anti-retreat steel plate is welded to the outer cabin plate of the bubble cabin, and the other side is welded to the main drive to ensure that the drive and the bubble cabin do not move relative to each other.

[0012] Preferably, the stop steel plate is welded on three sides to one side of the main drive and both sides of the bubble cabin, wherein the stop steel plate is connected to the main drive with stop steel plate weld one, the stop steel plate is connected to the horizontal side of the bubble cabin with stop steel plate weld four, and the stop steel plate is connected to the vertical side of the bubble cabin with stop steel plate weld three and stop steel plate weld two from top to bottom. The weld form is double-sided fillet weld, and the stop steel plate is not welded at the sealing position between the main drive and the bubble cabin.

[0013] Furthermore, the height of the stop plate satisfies the following formula, so as to better connect the bubble bulkhead plate and the main drive:

[0014]

[0015] Among them, H represents the height of the stop steel plate, D represents the inner diameter of the shield, d represents the outer diameter of the main drive, and h represents the height of the bubble cabin;

[0016] The width of the stop plate satisfies the following formula to ensure that the stop plate is installed in place:

[0017] B <M

[0018] Wherein, B represents the width of the stop steel plate, and M represents the distance from the base of the cylinder mounting ring to the bubble bulkhead plate.

[0019] Furthermore, the expression for the annular spacing of the upper semicircular arc stop steel plate in the first stage is as follows:

[0020]

[0021] Among them, N1 represents the number of upper semicircular arc stop steel plates, L1 represents the arc length of the upper semicircular arc installation range of the main drive, S1 represents the circumferential clear distance of the upper semicircular arc stop steel plates, and B represents the width of the stop steel plates;

[0022] The expression of the annular spacing of the lower semicircular arc stop steel plate in the first stage is as follows:

[0023]

[0024] Among them, N2 represents the number of lower semicircular arc stop steel plates, L2 represents the arc length of the lower semicircular arc installation range of the main drive, and S2 represents the circumferential clear distance of the lower semicircular arc stop steel plates.

[0025] Furthermore, the annular spacing arrangement of the stop steel plates within the arc length of the installation range of the left anti-twist oil cylinder in the second stage satisfies:

[0026]

[0027] Among them, S 左 Indicates the annular spacing of the stop steel plate within the arc length of the left anti-twist cylinder installation range, L 左 Indicates the arc length of the installation range of the left anti-twist cylinder, N 左 It indicates the number of stop steel plates within the installation range of the left anti-twist oil cylinder, and B indicates the width of the stop steel plate;

[0028] The annular spacing arrangement of the stop steel plates within the arc length of the installation range of the left anti-twist oil cylinder in the second stage meets the following requirements:

[0029]

[0030] Among them, S 右 Indicates the annular spacing of the stop steel plate within the arc length of the left anti-twist cylinder installation range, L 右 Indicates the arc length of the installation range of the left anti-twist cylinder, N 右 Indicates the number of retaining steel plates within the installation range of the left anti-torsion cylinder.

[0031] Preferably, in the first stage, in the finite element analysis software, a fixed constraint is applied to the weld connected to the bubble cabin, and a force F that a single stop steel plate needs to bear in the first stage is applied to the weld connected to the main drive. b, obtain the maximum stress and maximum shear force of each stop steel plate in the first stage, and verify whether the strength of the first stage meets the requirements. If the conditions are not met, adjust the number of stop steel plates and the circumferential clear distance of the stop steel plates until the strength meets the requirements.

[0032] Furthermore, the force F that a single stop plate needs to bear in the first stage b The determination includes the following steps:

[0033] First, measure the pressure of the oil rod chamber of each cylinder through the telescopic cylinder oil pressure gauge;

[0034] Then, the total cylinder thrust, i.e. the retreat force of the main drive telescopic cylinder, is calculated according to the following formula:

[0035]

[0036] F=F1+…+F n

[0037] Among them, F n represents the thrust of the nth cylinder, n is the total number of cylinders, D represents the cylinder diameter, P n It indicates the rod chamber pressure of the nth cylinder, and F indicates the total cylinder thrust, i.e. the cylinder retreat force;

[0038] Finally, according to the total cylinder retreat force, calculate the standard value of the longitudinal force that each stop steel plate needs to bear:

[0039] F N =F / N F

[0040] F b =1.35F N

[0041] Among them, F N Indicates the standard value of the longitudinal force borne by each stop plate, F b Indicates the design value of the longitudinal force borne by each stop plate, N F Indicates the total number of steel plates used for retreat in one stage.

[0042] Preferably, the first-stage strength verification includes the verification of the parent material strength:

[0043] σ max <f

[0044] τ max <f v

[0045] Among them, σ max Indicates the maximum stress of a single stop plate, τ max represents the maximum shear force of a single stop plate, f represents the design value of the tensile, compressive and bending strength of a single stop plate, and fv Indicates the design value of shear strength of a single piece of stop steel.

[0046] As an alternative, the first-stage strength verification includes the strength verification steps of the weld position where the stop plate is connected to the main drive as follows:

[0047]

[0048] τ f It represents the shear stress along the length of the weld calculated according to the effective cross section of the weld in the first stage, l w Indicates the calculated length of the fillet weld, h e represents the calculated thickness of the right-angle fillet weld, Indicates the design value of the fillet weld strength of the stop steel plate connected to the main drive.

[0049] As an alternative, the first-stage strength verification includes the strength verification of the weld position of the stop steel plate and the bubble tank:

[0050]

[0051] Among them, σ f It represents the stress of the effective cross-sectional area of ​​the weld in the direction perpendicular to the length of the weld in the first stage, τ f It represents the shear stress along the length of the weld according to the effective cross section of the weld, β f Increase the design value of fillet weld strength by a factor.

[0052] Furthermore, in the second stage, in the finite element analysis software, a fixed constraint is applied to the weld of the stopper steel plate connected to the bubble cabin, and a force F that a single stopper steel plate needs to bear in the second stage is applied to the weld connected to the main drive. b2 , obtain the maximum stress and maximum shear force of each stop steel plate in the second stage, and verify whether the second stage strength meets the requirements. If the conditions are not met, adjust the number of stop steel plates and the circumferential clear distance of the stop steel plates until the strength meets the requirements.

[0053] Furthermore, the force F that a single stop plate needs to bear in the second stage is b2 The determination includes the following steps:

[0054] First, calculate the second-stage main drive telescopic cylinder retreat force F n2 :

[0055] F n2 =F 后掌 +F 后贯 -F 先水土

[0056] Among them, F n2 Indicates the retreat force of the second-stage main drive telescopic cylinder, F 后掌 Indicates the supporting force of the tunnel face of the backward shield, F后贯 Indicates the penetration resistance of the subsequent shield, F 先水土 Indicates the water and soil load in front of the main drive of the leading shield.

[0057] Among them, the penetration resistance F 后贯 The calculation formula is as follows:

[0058] F 后贯 =F 后掘进接触力 -F 后静止接触力

[0059] Among them, F 后掘进接触力 Indicates the average contact force when the test ring starts to dig, F 后静止接触力 It indicates the contact force recorded when the shield is stationary before the test ring excavation begins.

[0060] Among them, the water and soil load F 先水土 Satisfy the following formula:

[0061] F 先水土 =F 先土荷载 +F 先水荷载

[0062] Among them, F 先土荷载 It represents the soil load in front of the leading shield, F 先水荷载 represents the water load in front of the leading shield.

[0063] Soil load F in front of the leading shield 先土荷载 Satisfy the following formula:

[0064] F 先土荷载 =K P yh d

[0065] Among them, F 先土荷载 represents the soil load in front of the leading shield, K P represents the passive earth pressure coefficient of the soil, γ represents the effective weight of the soil, h represents the depth of soil cover in the middle of the cutterhead, S d represents the surface area of ​​the cutter head,

[0066] Water load F in front of the leading shield 先水荷载 Satisfy the following formula:

[0067] F 先水荷载 =γ w h w S d

[0068] Among them, F 先水荷载 represents the water load in front of the leading shield, γ w Indicates the gravity of groundwater and Yangtze River water, h wIndicates the depth from the river surface to the middle of the cutterhead, S d Indicates the surface area of ​​the cutter head;

[0069] Then, according to the retreat force of the main drive telescopic cylinder in the second stage, the standard value of the longitudinal force F that each stop plate needs to bear in the second stage is calculated. b2 :

[0070] F a2 =F n2 / N S

[0071] F b2 =1.35F a2

[0072] Among them, F a2 Indicates the standard value of the longitudinal force borne by each stop plate, N S Indicates the number of second-stage stop steel plates.

[0073] The second stage strength calculation includes the calculation of parent material strength:

[0074] σ max2 <f

[0075] τ max2 <f v

[0076] Among them, σ max2 represents the maximum stress of the steel plate in the second stage of withdrawal, τ max2 represents the maximum shear force of the two-stage stop plate, f represents the design value of the tensile, compressive and bending strength of a single stop plate, and f v Indicates the design value of shear strength of a single piece of stop steel.

[0077] As an alternative, the second-stage strength verification includes the strength verification steps of the weld position where the stop plate is connected to the main drive as follows:

[0078]

[0079] τ f2 It indicates the shear stress along the length of the weld calculated according to the effective cross section of the weld in the second stage, l w Indicates the calculated length of the fillet weld, h e represents the calculated thickness of the right-angle fillet weld, Indicates the design value of the fillet weld strength of the stop steel plate connected to the main drive.

[0080] Furthermore, the second-stage strength verification includes the strength verification of the weld position of the stop steel plate and the bubble tank:

[0081]

[0082] Among them, σf2 It represents the stress of the effective cross-sectional area of ​​the second-stage weld in the direction perpendicular to the weld length, τ f2 It represents the shear stress along the length of the weld according to the effective cross section of the weld in the second stage, β f In the fillet weld strength design value increase factor, Indicates the design value of the fillet weld strength of the stop steel plate connected to the main drive.

[0083] Compared with the prior art, the present invention has the following beneficial effects:

[0084] The purpose of the present invention is to address the above-mentioned problems existing in the prior art, overcome the shortcomings of the prior art, and design a shield underground docking multi-stage main drive stop design method, which can effectively solve the problems of main drive retreat and damage to the main drive seal caused by long-term shutdown of the shield machine, which endanger the safety of the shield. The stop material accessories are universal and economical. After this method is used to stop the main drive of the shield that has been shut down for a long time, the water and soil pressure in front of the cutter disc is transmitted to the shield shell through the stop steel plate, making the structural force more reasonable, thereby sharing the water and soil pressure on the main drive. This stop method is universal for shield tunnels of different diameters. The present invention is highly creative and can be fully integrated into engineering practice, and has great promotion significance.

[0085] 1. The shield main drive of the present invention optimizes the design of the main drive stop, transfers the water and soil pressure in front of the cutter head to the shield shell through the stop steel plate, shares the force required by the main drive, makes the structural force more reasonable, and solves the problem of the main drive retreating.

[0086] 2. The present invention provides theoretical support for the rationality of the main drive stop design by verifying the strength of the stop steel plate base material and the weld, thereby ensuring the main drive stop effect.

[0087] 3. The present invention develops a one- or two-stage backstop design based on the stress conditions during the shield docking process, ensuring the safety of the main drive during the entire shield docking process. During the shield docking process, as the rear shield continues to approach, the backstop force of the main drive telescopic cylinder is different, so there are differences in the design basis of the main drive backstop reinforcement. Arranging the backstop steel plates in two stages can make the design basis more accurate and ensure construction safety. In addition, due to the different settings of the two-stage main drive peripheral anti-torsion cylinders, there are differences in the design and installation space of the backstop steel plates, so the backstop steel plates need to be designed in stages.

[0088] 4. The shield main drive anti-retreat reinforcement measures of the present invention are easy to construct, can reduce the construction period, avoid construction risks, and thus generate economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0090] Figure 1 is a flow chart of the best embodiment of the present invention;

[0091] Figure 2 This is the installation position diagram of the stop steel plate;

[0092] Figure 3 It is the plane size design of the stop steel plate;

[0093] Figure 4 It is the weld location map;

[0094] Figure 5 This is the internal structure diagram of the shield machine;

[0095] Figure 6 It is the installation position of the stop steel plate and the position diagram of the weld;

[0096] Figure 7 It is a layout diagram of the steel plate for stopping retreat in one stage;

[0097] Figure 8 This is the layout diagram of the two-stage anti-retraction steel plate. DETAILED DESCRIPTION

[0098] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0099] A shield tunneling multi-stage main drive stop design method Figure 1-Figure 8 , including the following steps:

[0100] S1: Determination of the plane dimensions of the main drive reinforcement stop steel plate;

[0101] S2: Determination of the range of the weld of the stop steel plate;

[0102] S3: Determination of the thickness and number of the first-stage stop steel plates;

[0103] S4: The retreat force of the main drive telescopic cylinder in the first stage is determined, which is used as the basis for the design of the main drive anti-retreat reinforcement;

[0104] S5: Verification of the strength of the stop steel plate parent material;

[0105] S6: Strength verification of the weld of the stop steel plate at one position;

[0106] S7: Strength verification of stop steel plate weld seam 2 and stop steel plate weld seam 3;

[0107] S8: If the calculation is satisfied, arrange the circumferential spacing of the stop steel plates. If not satisfied, return to S3;

[0108] S9: Determination of the thickness and number of the second-stage stop steel plates;

[0109] S10: The retreat force of the second-stage main drive telescopic cylinder is determined, which is used as the basis for the main drive anti-retreat reinforcement design;

[0110] S11: Verification of the strength of the parent material of the stop steel plate;

[0111] S12: Strength verification of the weld of the stop steel plate at one position;

[0112] S13: Strength verification of stop steel plate weld seam 2 and stop steel plate weld seam 3;

[0113] S14: If the calculation is satisfied, arrange the circumferential spacing of the stop steel plates; if not, return to S9;

[0114] Furthermore, the steps for determining the plane size of the main driving reinforcement anti-retraction steel plate in step S1 are as follows:

[0115] S1.1: The main drive is located at the center of the shield machine and is closely connected to the bubble cabin partition all around. To ensure that the main drive and the bubble cabin do not move relative to each other, a stop plate is set at the intersection of the bubble cabin and the main drive. With the help of the "L"-shaped structure of the bubble cabin, one side of the stop plate is welded to the outer cabin plate of the bubble cabin, and the other side is welded to the main drive. The stop plate is designed to be placed as follows: Figure 2 , Figure 5 and Figure 6 Position shown.

[0116] S1.2: The design location of the stop steel plate provides space for operation and is in a normal pressure environment to reduce construction risks.

[0117] S1.3: The height of the stop plate is set as follows:

[0118]

[0119] H represents the height of the stop steel plate (m),

[0120] D is the inner diameter of the shield (m),

[0121] d represents the outer diameter of the main drive (m),

[0122] h is the height of the bubble chamber (m).

[0123] S14: The width of the stop plate is set as follows:

[0124] B <M

[0125] B represents the width of the stop steel plate (m),

[0126] M represents the distance from the oil cylinder mounting ring base to the bubble bulkhead plate (m).

[0127] S15: According to the measured spatial position relationship between the bubble cabin and the main drive, and using the surface shape characteristics of the bubble cabin and the main drive structure, the plane dimensions of the anti-retraction steel plate are designed as follows: Figure 3 , to ensure that the anti-retraction steel plate fits tightly with both, achieving better anti-retraction sealing effect.

[0128] Furthermore, the steps for determining the range of the weld seam of the steel plate to be withdrawn in step S2 are as follows:

[0129] S2.1: The main drive stop plate is welded on three sides with one side of the main drive and both sides of the bubble tank. Figure 4 As shown in the figure, the stop steel plate weld 1, stop steel plate weld 2, stop steel plate weld 3 and stop steel plate weld 4 are double-sided fillet welds with weld foot height hf=20mm, which can improve the mechanical properties of three-sided welding to a certain extent, bring out the ultimate strength of each weld section more fully, and effectively improve the bearing capacity and safety reserve of the structure.

[0130] S2.2: The stop steel plate is not welded at the main drive and bubble chamber sealing position, which can effectively avoid scalding the main drive seal.

[0131] like Figure 7 The figure shows the layout of the first-stage stop-retreat steel plates. The thickness and number of the first-stage stop-retreat steel plates in step S3 are determined as follows:

[0132] S3.1: When the plane size of the stop steel plate is determined, its thickness determines the weight of the steel plate. Considering the operability and convenience of construction, the thickness of the stop steel plate is 28mm.

[0133] S3.2: There is an anti-torsion cylinder on each side of the main drive waist, so the anti-retraction steel plate can only be installed on the upper and lower semi-circular arcs, and the anti-retraction steel plate and the anti-torsion cylinder must maintain a construction distance of at least 400mm in the circumferential direction. This can be used to preliminarily determine the number of anti-retraction steel plates.

[0134] Furthermore, the steps for determining the retreat force of the main driving telescopic cylinder in the first stage in step S4 are as follows:

[0135] S4.1: Measure the pressure of the oil rod chamber of each cylinder using the telescopic cylinder oil pressure gauge.

[0136] S4.2: The total cylinder thrust is equal to the sum of the thrusts of each cylinder. The thrust of each cylinder is equal to the different pressures in each cylinder multiplied by the internal surface area of ​​the cylinder. Therefore, the total cylinder thrust, i.e. the retreat force of the main drive telescopic cylinder, is calculated according to the following calculation formula.

[0137]

[0138] F=F1+…+F n

[0139] F n Indicates the thrust of the nth cylinder (KN), where n is the total number of cylinders.

[0140] D represents the diameter of the oil cylinder (mm),

[0141] P n Indicates the rod chamber pressure of the nth cylinder (MPa),

[0142] F represents the total cylinder thrust (KN) (i.e. the cylinder retraction force).

[0143] Preferably, the step of stopping the verification of the strength of the base material of the steel-retreated plate in step S5 is as follows:

[0144] S5.1: Based on the total cylinder back-off force, the standard value of the longitudinal force that each back-off steel plate needs to bear and the design value of the force that the fillet weld needs to bear can be calculated as follows:

[0145] F N =F / N F

[0146] F b =1.35F N

[0147] F N Indicates the standard value of the longitudinal force borne by each retaining steel plate (KN),

[0148] F b Indicates the design value of the longitudinal force borne by each retaining steel plate (KN),

[0149] N F Indicates the total number of steel plates used for retreat in one stage.

[0150] S5.2: In the finite element analysis software, fixed constraints are applied to the stopper steel plate weld seams 2, 3, and 4 connected to the bubble cabin, and the force F that a single stopper steel plate needs to bear is applied to the stopper steel plate weld seam 1. b , and obtain the maximum stress and maximum shear force of each stop steel plate.

[0151] S5.3: Based on the finite element analysis results, verify whether the parent material strength meets the requirements as follows:

[0152] σ max <f

[0153] τ max <f v

[0154] σ max Indicates the maximum stress of a single stop steel plate,

[0155] τ max Indicates the maximum shear force of a single stop steel plate,

[0156] f represents the design value of tensile, compressive and bending strength of a single stop steel plate. Here, Q355 steel is used, that is, f = 290N / mm2.

[0157] f v It represents the design value of shear strength of a single retaining steel plate. Here, Q355 steel is used, that is, fv=170N / mm2.

[0158] Preferably, the step S6 of stopping the strength verification step of the weld seam of the steel plate is as follows:

[0159] S6.1: The stop plate weld transmits the horizontal thrust to the stop plate, and the force direction is parallel to the weld, which is a side fillet weld. The verification is as follows:

[0160]

[0161] τ f It indicates the shear stress along the length of the weld calculated according to the effective cross section of the weld (N / mm 2 ),

[0162] l w Indicates the calculated length of the fillet weld (mm). For each weld, take its actual length minus 2h f ,

[0163] h e Indicates the calculated thickness of the right-angle fillet weld (mm),

[0164] It represents the design value of the fillet weld strength of the stop steel plate connected to the main drive (180N / mm2), where Q355 steel is used.

[0165] Furthermore, the strength verification steps of the second and third positions of the stop-withdrawal steel plate weld seams in step S7 are as follows:

[0166] S7.1: The stresses at the positions of the second and third weld seams of the stop steel plate are relatively complex, and are subjected to both normal stress and shear stress. Finite element analysis is adopted, and its working load and boundary conditions are the same as those set in step S42, to obtain the shear stress and horizontal stress distribution of the stop steel plate.

[0167] S7.2: Under the combined action of forces, the stop plate weld seam 2 and the stop plate weld seam 3 must satisfy the following verification formula:

[0168]

[0169] σ f Indicates the stress (N / mm) in the effective cross-sectional area of ​​the weld (helw) perpendicular to the length of the weld 2 ), h f Indicates the size of the weld leg.

[0170] τ f It indicates the shear stress along the length of the weld calculated according to the effective cross section of the weld (N / mm 2 ),

[0171] β f Indicates the fillet weld strength design value increase factor (β f =1.0).

[0172] Furthermore, in step S8, the annular spacing arrangement of the first-stage stop steel plates is as follows:

[0173] S8.1: According to the number of stopper steel plates determined when the first stage advance shield machine is in the shutdown state, the stopper steel plates are arranged along the outer surface of the main drive. When the left and right anti-torque cylinders are not removed, the main drive stopper steel plates of the upper and lower arcs are installed first. The installation space of the upper and lower arcs can be determined based on actual measurements. The annular spacing expression of the stopper steel plates of the upper arc can be derived as follows (the calculation method of the upper and lower arcs is the same):

[0174]

[0175] B represents the width of the stop plate.

[0176] N1 and N2 represent the number of upper and lower semicircular arc stop steel plates, respectively.

[0177] L1 and L2 represent the length of the upper and lower semicircular arcs of the main drive that can be installed (mm).

[0178] S1 and S2 represent the circumferential clearance (mm) of the upper and lower semicircular arcs of the first-stage stop steel plate, respectively (considering operability S≥400mm).

[0179] Preferably, Figure 8 The figure shows the layout of the two-stage stop-withdrawal steel plates, and the determination of the thickness and number of the two-stage stop-withdrawal steel plates in step S9:

[0180] S9.1: The thickness of the second-stage stop plate shall be the same as the thickness of the first-stage stop plate.

[0181] S9.2: The upper and lower arc stop plates of the first stage have been completed, and the left and right anti-torque cylinders of the second stage have been removed. The vacated positions can be used to continue to lay out the stop plates. It is still necessary to ensure that the construction distance of the stop plates is at least 400mm when they are reversed. This can be used to preliminarily determine the number of stop plates.

[0182] Furthermore, the steps for determining the retreat force of the second-stage main drive telescopic cylinder in step S10 are as follows:

[0183] S10.1: When the rear shield machine advances to a distance less than three times the diameter of the leading shield machine, the retreat force of the second-stage main drive telescopic cylinder is the combined force of the rear shield machine's face support force, the rear shield machine's penetration resistance, and the water and soil load in front of the leading shield machine's main drive.

[0184] F n2 =F 后掌 +F 后贯 -F 先水土

[0185] F n2 Indicates the back force of the second-stage main drive telescopic cylinder (KN),

[0186] F 后掌 Indicates the supporting force of the rear shield tunnel face (KN) (read by the rear shield machine system).

[0187] F 后贯 Indicates the penetration resistance of the subsequent shield machine (KN) (measured by the penetration resistance test of the subsequent shield machine),

[0188] F 先水土 Indicates the water and soil load in front of the main drive of the leading shield (KN):

[0189] F 先水土 =F 先土荷载 +F 先水荷载

[0190] F 先土荷载 It represents the soil load in front of the leading shield, F 先水荷载 Indicates the water load in front of the advance shield.

[0191] S10.2: Select five rings within a distance of three times the shield diameter between the previous and next shields as test rings. The geological conditions and burial depth of the test rings are basically the same as those of the docking position. The average value of the five test ring results is taken as the penetration resistance value of the subsequent shield. The calculation formula is as follows:

[0192] F 后贯 =F 后掘进接触力 -F 后静止接触力

[0193] F 后掘进接触力It means that when the test ring starts to dig, the average value of the digging contact force (KN) is taken.

[0194] F 后静止接触力 It indicates the contact force (KN) recorded when the shield is stationary before the test ring excavation starts.

[0195] S10.3: As the following shield machine gradually approaches the leading shield machine, the water and soil loads in front of the main drive of the leading shield machine gradually disappear, so they need to be reduced.

[0196] F 先土荷载 =K P yh d

[0197] F 先土荷载 It represents the soil load in front of the leading shield.

[0198] K P Represents the passive earth pressure coefficient of the soil, usually between 1 / 3 and 1 / 2.

[0199] γ represents the effective weight of soil (kN / m 3 ),

[0200] h represents the soil cover depth in the middle of the cutter disc (m),

[0201] S d Indicates the surface area of ​​the cutter head (m 2 ).

[0202] F 先水荷载 =γ w h w S d

[0203] F 先水荷载 represents the water load in front of the leading shield.

[0204] γ w Indicates the density of groundwater and Yangtze River water (kN / m 3 ),

[0205] h w Indicates the depth from the river surface to the middle of the cutter head (m).

[0206] S d Indicates the surface area of ​​the cutter head (m 2 ).

[0207] Preferably, the step S11 of stopping the verification of the strength of the base material of the steel-retreated plate is as follows:

[0208] S11.1: Based on the retreat force of the second-stage main drive telescopic cylinder, the standard value of the longitudinal force that each stop plate needs to bear and the design value of the force that the fillet weld needs to bear can be calculated as follows:

[0209] F a2 =F n2 / N S

[0210] F b2 =1.35F a2

[0211] F a2 Indicates the standard value of the longitudinal force borne by each retaining steel plate (KN),

[0212] F b2 Indicates the design value of the longitudinal force borne by each retaining steel plate (KN),

[0213] N2 represents the number of second-stage stop steel plates.

[0214] S11.2: In the finite element analysis software, fixed constraints are applied to the stopper steel plate weld seams 2, 3, and 4 connected to the bubble tank, and the force F that a single stopper steel plate needs to bear is applied to the stopper steel plate weld seam 1. b2 , the maximum stress and maximum shear force of the stop plate are obtained. According to the finite element analysis results, the parent material strength is checked to see if it meets the requirements, as follows:

[0215] σ max2 <f

[0216] τ max2 <f v

[0217] σ max2 represents the maximum stress of the steel plate in the second stage of withdrawal,

[0218] τ max2 represents the maximum shear force of the second-stage stop plate,

[0219] f represents the design value of tensile, compressive and bending strength of a single stop steel plate. Here, Q355 steel is used, that is, f = 290N / mm2.

[0220] f v It represents the design value of shear strength of a single retaining steel plate. Here, Q355 steel is used, that is, fv=170N / mm2.

[0221] Further, the step S12 of stopping the strength verification of the weld seam of the steel plate at one position is as follows:

[0222] S12.1: Weld 1 transmits the horizontal thrust to the stop plate, and the force direction is parallel to the weld, which is a side fillet weld. The verification is as follows:

[0223]

[0224] τ f2It indicates the shear stress along the length of the weld calculated according to the effective cross section of the weld (N / mm 2 ),

[0225] l w Indicates the calculated length of the fillet weld (mm). For each weld, take its actual length minus 2h f ,

[0226] h e Indicates the calculated thickness of the right-angle fillet weld (mm),

[0227] It indicates the design value of Q355 steel fillet weld strength (180N / mm2).

[0228] The strength verification steps of the stop-withdrawal steel plate weld seam 2 and the stop-withdrawal steel plate weld seam 3 in step S13 are as follows:

[0229] S13.1: The forces at the positions of the stop plate weld seams 2 and 3 are relatively complex, and are subjected to both normal stress and shear stress. Finite element analysis is used, and the working load and boundary conditions are the same as those set in step S112 to obtain the shear stress and horizontal stress distribution of the stop plate. Under the combined action of forces, the stop plate weld seams 2 and 3 must meet the following verification formula:

[0230]

[0231] σ f2 Indicates the effective cross-sectional area of ​​the second-stage weld (h e l w ) calculation, stress perpendicular to the length of the weld (N / mm 2 ),

[0232] τ f2 It indicates the shear stress along the length of the weld calculated according to the effective cross section of the two-stage weld (N / mm 2 ),

[0233] β f Indicates the fillet weld strength design value increase factor (β f =1.0).

[0234] Furthermore, the annular spacing arrangement of the second-stage stop steel plates in step S14 is:

[0235] S14.1: The upper and lower arc-shaped stop steel plates of the first stage have been installed, and the left and right anti-torsion cylinders have been removed. On this basis, the circumferential spacing of the stop steel plates within the arc length of the left anti-torsion cylinder installation range is arranged (the arrangement method of the left and right positions is the same):

[0236]

[0237] B represents the width of the stop plate.

[0238] S 左 , S 右 Respectively represent the circumferential spacing of the stop steel plates within the arc length of the left and right anti-torque cylinder installation range (mm),

[0239] L 左 , L 右 Respectively represent the arc length of the installation range of the left and right anti-torque cylinders (mm),

[0240] N 左 、N 右 Respectively represent the number of retaining steel plates within the installation range of the left and right anti-torsion cylinders.

[0241] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A shield tunneling underground docking multi-stage main drive stop design method according to claim 1, characterized in that: The underground docking of the shield is divided into two stages based on the distance between the preceding shield and the succeeding shield. In the first stage, anti-retraction steel plates are arranged along the outer surface of the main drive. When the left and right anti-torque cylinders are not removed, the upper and lower semi-arc main drive anti-retraction steel plates are installed first. In the second stage, the left and right anti-torque cylinders of the main drive are removed, and the vacated position is used to continue to arrange the anti-retraction steel plates.

2. A shield tunneling underground docking multi-stage main drive stop design method according to claim 1, characterized in that: The anti-retraction steel plate is set at the intersection of the bubble cabin and the main drive. With the help of the L-shaped structure of the bubble cabin, one side of the anti-retraction steel plate is welded to the outer cabin plate of the bubble cabin, and the other side is welded to the main drive to ensure that the drive and the bubble cabin do not move relative to each other.

3. A shield tunneling underground docking multi-stage main drive stop design method according to claim 2, characterized in that: The stop steel plate is welded on three sides with one side of the main drive and both sides of the bubble cabin, among which, the junction of the stop steel plate and the main drive is stop steel plate weld one, the junction of the stop steel plate and the horizontal side of the bubble cabin is stop steel plate weld four, and the junction of the stop steel plate and the vertical side of the bubble cabin are stop steel plate weld three and stop steel plate weld two from top to bottom. The weld form is double-sided fillet weld, and the stop steel plate is not welded at the sealing position of the main drive and the bubble cabin.

4. A shield tunneling underground docking multi-stage main drive stop design method according to claim 2, characterized in that: The height of the stop plate satisfies the following formula to better connect the bubble bulkhead plate and the main drive: Among them, H represents the height of the stop steel plate, D represents the inner diameter of the shield, d represents the outer diameter of the main drive, and h represents the height of the bubble cabin; The width of the stop plate satisfies the following formula to ensure that the stop plate is installed in place: B <M Wherein, B represents the width of the stop steel plate, and M represents the distance from the base of the cylinder mounting ring to the bubble bulkhead plate.

5. The method for designing a multi-stage main drive stop for underground docking of a shield machine according to claim 1, characterized in that: The expression of the annular spacing of the upper semicircular arc stop steel plate in the first stage is as follows: Among them, N1 represents the number of upper semicircular arc stop steel plates, L1 represents the arc length of the upper semicircular arc installation range of the main drive, S1 represents the circumferential clear distance of the upper semicircular arc stop steel plates, and B represents the width of the stop steel plates; The expression of the annular spacing of the lower semicircular arc stop steel plate in the first stage is as follows: Among them, N2 represents the number of lower semicircular arc stop steel plates, L2 represents the arc length of the lower semicircular arc installation range of the main drive, and S2 represents the circumferential clear distance of the lower semicircular arc stop steel plates.

6. The method for designing a multi-stage main drive stop for underground docking of a shield machine according to claim 1, characterized in that: The annular spacing arrangement of the stop steel plates within the arc length of the installation range of the left anti-twist oil cylinder in the second stage meets the following requirements: Among them, S 左 Indicates the annular spacing of the stop steel plate within the arc length of the left anti-twist cylinder installation range, L 左 Indicates the arc length of the installation range of the left anti-twist cylinder, N 左 It indicates the number of stop steel plates within the installation range of the left anti-twist oil cylinder, and B indicates the width of the stop steel plate; The annular spacing arrangement of the stop steel plates within the arc length of the installation range of the left anti-twist oil cylinder in the second stage meets the following requirements: Among them, S 右 Indicates the annular spacing of the stop steel plate within the arc length of the left anti-twist cylinder installation range, L 右 Indicates the arc length of the installation range of the left anti-twist cylinder, N 右 Indicates the number of retaining steel plates within the installation range of the left anti-torsion cylinder.

7. The method for designing a multi-stage main drive stop for underground docking of a shield machine according to claim 1, characterized in that: In the first stage, in the finite element analysis software, a fixed constraint is applied to the weld connected to the bubble cabin, and a force F that a single stop plate needs to bear is applied to the weld connected to the main drive. b , obtain the maximum stress and maximum shear force of each stop steel plate in the first stage, and verify whether the strength of the first stage meets the requirements. If the conditions are not met, adjust the number of stop steel plates and the circumferential clear distance of the stop steel plates until the strength meets the requirements.

8. A shield tunneling underground docking multi-stage main drive stop design method according to claim 7, characterized in that: The force F that a single stop plate needs to bear in the first stage b The determination includes the following steps: First, measure the pressure of the oil rod chamber of each cylinder through the telescopic cylinder oil pressure gauge; Then, the total cylinder thrust, i.e. the retreat force of the main drive telescopic cylinder, is calculated according to the following formula: F=F1+…+F n Among them, F n represents the thrust of the nth cylinder, n is the total number of cylinders, D represents the cylinder diameter, P n It indicates the rod chamber pressure of the nth cylinder, and F indicates the total cylinder thrust, i.e. the cylinder retreat force; Finally, according to the total cylinder retreat force, calculate the standard value of the longitudinal force that each stop steel plate needs to bear: F N =F / N F F b =1.35F N Among them, F N Indicates the standard value of the longitudinal force borne by each stop plate, F b Indicates the design value of the longitudinal force borne by each stop plate, N F Indicates the total number of steel plates used for retreat in one stage.

9. A shield tunneling underground docking multi-stage main drive stop design method according to claim 7, characterized in that: The first-stage strength verification includes the verification of the parent material strength: s max <f t max <f v Among them, σ max Indicates the maximum stress of a single stop steel plate, τ max represents the maximum shear force of a single stop plate, f represents the design value of the tensile, compressive and bending strength of a single stop plate, and f v Indicates the design value of shear strength of a single piece of stop steel.

10. A shield tunneling underground docking multi-stage main drive stop design method according to claim 7, characterized in that: The first stage strength verification includes the strength verification steps of the weld where the stop plate is connected to the main drive as follows: τ f It represents the shear stress along the length of the weld calculated according to the effective cross section of the weld in the first stage, l w Indicates the calculated length of the fillet weld, h e represents the calculated thickness of the right-angle fillet weld, Indicates the design value of the fillet weld strength of the stop steel plate connected to the main drive.

11. A shield tunneling underground docking multi-stage main drive stop design method according to claim 7, characterized in that: The first stage strength verification includes the strength verification of the stop steel plate and the bubble tank weld position: Among them, σ f It represents the stress of the effective cross-sectional area of ​​the weld in the direction perpendicular to the length of the weld in the first stage, τ f It represents the shear stress along the length of the weld according to the effective cross section of the weld, β f In the fillet weld strength design value increase factor, Indicates the design value of the fillet weld strength of the stop steel plate connected to the main drive.

12. A shield tunneling underground docking multi-stage main drive stop design method according to claim 1, characterized in that: In the second stage, in the finite element analysis software, a fixed constraint is applied to the weld of the stopper steel plate connected to the bubble cabin, and a force F that a single stopper steel plate needs to bear in the second stage is applied to the weld connected to the main drive. b2 , obtain the maximum stress and maximum shear force of each stop steel plate in the second stage, and verify whether the second stage strength meets the requirements. If the conditions are not met, adjust the number of stop steel plates and the circumferential clear distance of the stop steel plates until the strength meets the requirements.

13. A shield tunneling underground docking multi-stage main drive stop design method according to claim 12, characterized in that: The force F that a single stop plate needs to bear in the second stage b2 The determination includes the following steps: First, calculate the second-stage main drive telescopic cylinder retreat force F n2 : F n2 =F 后掌 +F 后贯 -F 先水土 Among them, F n2 Indicates the retreat force of the second-stage main drive telescopic cylinder, F 后掌 Indicates the supporting force of the tunnel face of the backward shield, F 后贯 Indicates the penetration resistance of the subsequent shield, F 先水土 Indicates the water and soil load in front of the main drive of the leading shield. Among them, the penetration resistance F 后贯 The calculation formula is as follows: F 后贯 =F 后掘进接触力 -F 后静止接触力 Among them, F 后掘进接触力 Indicates the average contact force when the test ring starts to dig, F 后静止接触力 It indicates the contact force recorded when the shield is stationary before the test ring excavation begins. Among them, the water and soil load F 先水土 Satisfy the following formula: F 先水土 =F 先土荷载 +F 先水荷载 Among them, F 先土荷载 It represents the soil load in front of the leading shield, F 先水荷载 represents the water load in front of the leading shield. Soil load F in front of the leading shield 先土荷载 Satisfy the following formula: F 先土荷载 =K P γhS d Among them, F 先土荷载 represents the soil load in front of the leading shield, K P represents the passive earth pressure coefficient of the soil, γ represents the effective weight of the soil, h represents the depth of soil covering the middle of the cutterhead, S d represents the surface area of ​​the cutter head, Water load F in front of the leading shield 先水荷载 Satisfy the following formula: F 先水荷载 =γ w h w S d Among them, F 先水荷载 represents the water load in front of the leading shield, γ w Indicates the gravity of groundwater and Yangtze River water, h w Indicates the depth from the river surface to the middle of the cutterhead, S d Indicates the surface area of ​​the cutter head; Then, according to the retreat force of the main drive telescopic cylinder in the second stage, the standard value of the longitudinal force F that each stop plate needs to bear in the second stage is calculated. b2 : F a2 =F n2 / N S F b2 =1.35F a2 Among them, F a2 Indicates the standard value of the longitudinal force borne by each stop plate, N S Indicates the number of second-stage stop steel plates.

14. A shield tunneling underground docking multi-stage main drive stop design method according to claim 12, characterized in that: The second stage strength calculation includes the calculation of parent material strength: s max2 <f t max2 <f v Among them, σ max2 represents the maximum stress of the steel plate in the second stage of withdrawal, τ max2 represents the maximum shear force of the two-stage stop plate, f represents the design value of the tensile, compressive and bending strength of a single stop plate, and f v Indicates the design value of shear strength of a single piece of stop steel.

15. A shield tunneling underground docking multi-stage main drive stop design method according to claim 12, characterized in that: The second stage strength verification includes the strength verification steps of the weld where the stop plate is connected to the main drive as follows: τ f2 It indicates the shear stress along the length of the weld calculated according to the effective cross section of the weld in the second stage, l w Indicates the calculated length of the fillet weld, h e represents the calculated thickness of the right-angle fillet weld, Indicates the design value of the fillet weld strength of the stop steel plate connected to the main drive.

16. A shield tunneling underground docking multi-stage main drive stop design method according to claim 12, characterized in that: The second stage strength verification includes the strength verification of the stop steel plate and the bubble tank weld position: Among them, σ f2 It represents the stress of the effective cross-sectional area of ​​the second-stage weld in the direction perpendicular to the weld length, τ f2 It represents the shear stress along the length of the weld according to the effective cross section of the weld in the second stage, β f In the fillet weld strength design value increase factor, Indicates the design value of the fillet weld strength of the stop steel plate connected to the main drive.

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