A method for calculating the support pressure of a trailing shield tunnel face suitable for high water pressure and water permeable strata shield in-situ butt joint

Abstract

The present application relates to the technical field of shield tunnel engineering, and discloses a method for calculating the support pressure of the trailing shield tunnel face in the shield ground butt joint suitable for high water pressure and water permeable stratum, which comprises the following steps: establishing the balance relationship of the shield ground butt joint in combination with the mechanical balance analysis of the shield ground butt joint process; calculating the cutter penetration resistance under different tunneling speeds based on the penetration resistance test of the stratum near the butt joint; and calculating the support pressure of the trailing shield tunnel face and guiding the tunneling construction by using the support pressure of the trailing shield tunnel face under different tunneling speeds. The present application can effectively solve the problem of parameter setting of the trailing shield tunnel in the close approach tunneling process, and the balance formula has universality for similar shield butt joint engineering. Through the penetration resistance test of the close approach stratum, the corresponding relationship between the penetration resistance of the butt joint position and the tunneling speed can be truly reflected, and then the setting value of the support pressure of the trailing shield tunnel face is obtained, thereby providing a theoretical basis for the setting of the tunneling parameters of the trailing shield.

Description

Technical Field

[0001] This invention relates to the field of shield tunnel engineering technology, and more specifically, to a method for calculating the support pressure at the face of a subsequent shield tunnel during underground docking in high water pressure and permeable strata. Background Technology

[0002] In recent years, with the acceleration of urbanization, the demand for urban underground space development has been increasing. Shield tunnels, as an effective way to solve traffic problems, connect railway and highway trunk lines, not only expanding the transportation network but also improving transportation efficiency and promoting regional economic development. With the continuous development of shield tunneling technology in my country, the speed and efficiency of tunnel construction have been greatly improved, while reducing the impact of construction on the ground environment. The underground docking method is one of the effective methods to improve efficiency and shorten the construction period in long-distance tunnel excavation, especially in long-distance tunnel construction crossing straits, rivers, and mountains.

[0003] Currently, during the implementation of the underground docking method for tunnel boring machines (TBMs), the preceding TBM inevitably needs to be stationary, as its slurry chamber is already filled with mortar. During the subsequent TBM's close-proximity tunneling, unreasonable support pressure and tunneling speed will inevitably have a negative impact on both the preceding and following TBMs and their internal structures. Therefore, it is necessary to provide a reasonable method for setting the support pressure of the following TBM and control its tunneling speed within a reasonable range to ensure the safety of the docking construction.

[0004] Publication No. CN112307547A discloses a method for designing support pressure at the tunnel face. This method uses numerical calculation software to iterate based on a specified target safety factor and an initial value of support pressure until the calculated safety factor matches the target safety factor; the corresponding support pressure at this point is the target value. However, this method cannot address the issue of additional loads from the subsequent shield tunneling machine to the preceding shield tunneling machine in underground docking scenarios, thus having certain limitations.

[0005] Despite the significant work done in existing publicly available research, the following technical challenges remain unresolved:

[0006] 1. During the underground docking process of shield tunneling, it is difficult to grasp the additional stress generated by the subsequent shield tunneling on the preceding shield.

[0007] 2. During the tunnel boring machine (TBM) excavation process, the resistance to the cutter penetration is immeasurable.

[0008] 3. During the underground docking process of the shield tunneling machine, there is no clear calculation basis for the construction parameters of the subsequent shield tunneling.

[0009] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0010] To address the problems in related technologies, this invention proposes a method for calculating the support pressure of the tunnel face of a subsequent shield tunneling machine in ground docking in high water pressure and permeable strata, thereby overcoming the aforementioned technical problems existing in the current related technologies.

[0011] This invention divides the project into two stages based on the distance between the preceding and following tunnel boring machines (TBMs). In the first stage, when the distance is large, the support pressure of the following TBM face is calculated using conventional methods. In the second stage, after the distance is reduced to a certain level, the mechanical equilibrium relationship during the near-contact tunneling process of the TBMs is analyzed, and an equilibrium formula for calculating the support pressure of the following TBM face is given. Based on the stress characteristics of the TBM cutter during tunneling, a calculation formula and test method for the cutter penetration resistance are given. Through penetration resistance tests of the TBM tunneling in the adjacent strata of the docking section, the penetration resistance value of the following TBM cutter at different tunneling speeds is calculated, further guiding the design of the support pressure of the following TBM face. The design method can be practically implemented and is suitable for industry promotion.

[0012] Therefore, the specific technical solution adopted by the present invention is as follows:

[0013] A method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in high water pressure and highly permeable strata includes the following steps:

[0014] S1. Based on the distance relationship between the subsequent shield tunneling and the preceding shield tunneling, and combined with the mechanical balance analysis of the shield tunneling docking process in the ground, establish the shield tunneling docking balance relationship in the ground to ensure that the additional stress generated by the subsequent shield tunneling is zero.

[0015] S2. Determine the tunneling speed of the subsequent shield tunneling machine in different tunneling test stages, and determine the tunneling time for each tunneling test stage; based on the penetration resistance test of the adjacent strata, calculate the cutter penetration resistance at different tunneling speeds;

[0016] S3. Based on the cutter penetration resistance at different tunneling speeds, and combined with the shield docking balance relationship in the ground, calculate the support pressure of the subsequent shield face, and use the support pressure of the subsequent shield face at different tunneling speeds to guide the tunneling construction, so as to maintain the stability of the preceding shield.

[0017] Furthermore, the step of establishing a ground-based shield docking equilibrium relationship based on the distance relationship between the subsequent shield tunneling and the preceding shield tunneling, combined with the mechanical equilibrium analysis of the shield docking process in the ground, to ensure that the additional stress generated by the subsequent shield tunneling is zero, includes the following steps:

[0018] S11. Determine whether the proximity of the following shield tunneling to the preceding shield tunneling is greater than three times the shield diameter. If yes, ignore the impact of the following shield tunneling on the preceding shield tunneling. If no, execute S12.

[0019] S12. Based on the mechanical equilibrium relationship during the shield tunneling process, and combined with the state of the subsequent shield tunnel, a shield tunneling equilibrium formula is established to ensure that the additional stress generated by the subsequent shield tunneling is zero.

[0020] Furthermore, the establishment of a shield-to-ground docking equilibrium formula based on the mechanical equilibrium relationship during the shield-to-ground docking process, combined with the state of the subsequent shield, to ensure that the additional stress generated by the subsequent shield's close-proximity excavation is zero includes:

[0021] When the rear tunneling machine is stationary, in order to ensure that the additional stress generated by the rear tunneling machine on the preceding tunneling machine is zero, the force generated by the rear tunneling machine must be balanced with the static earth pressure of the preceding tunneling machine, so as to obtain the equilibrium formula for the ground docking of the tunneling machines in a stationary state.

[0022] When the subsequent shield is in the tunneling state, in order to ensure that the additional stress generated by the subsequent shield tunneling on the preceding shield is zero, the force generated by the subsequent shield tunneling must be balanced with the static earth pressure of the preceding shield, so as to obtain the shield docking equilibrium formula in the tunneling state.

[0023] Furthermore, the expression for the shield tunneling ground docking equilibrium formula in the static state is as follows:

[0024] Q 先静 =Q 后掌

[0025] Q 先静 =K0·γ·Z

[0026] The expression for the shield tunneling ground docking equilibrium formula during tunneling is as follows:

[0027] Q 先静 =Q 后掌 +Q 后贯

[0028] In the formula, Q 先静 Q represents the static earth pressure of the preceding shield tunneling machine. 后掌 The following values ​​represent the support pressure at the tunnel face of the rearward-moving shield, K0 represents the coefficient of earth pressure at rest, γ represents the unit weight of the fill, Z represents the bottom depth of the tunnel boring machine, and Q represents the support pressure at the tunnel face of the rearward-moving shield. 后贯 This indicates the pressure exerted by the subsequent tunnel boring machine (TBM) during penetration.

[0029] Furthermore, determining the tunneling speed of the subsequent shield tunneling machine at different tunneling test stages and determining the tunneling time for each tunneling test stage; and calculating the cutter penetration resistance at different tunneling speeds based on the penetration resistance test of the adjacent strata, includes the following steps:

[0030] S21. Select a ring of the adjacent docking section as the test ring, set the tunneling distance of the test ring and the tunneling speed of different tunneling test stages, and determine the tunneling time of each tunneling test stage according to the tunneling speed.

[0031] S22. Before the test begins, record the static contact force of the rear tunnel boring machine when it is stationary, and conduct a tunneling test simulation based on the set tunneling speed and tunneling time.

[0032] S23. After the test ring tunneling is completed, record the contact force of the rear tunneling shield at different tunneling speeds, and calculate the cutter penetration resistance at different tunneling speeds based on the recorded contact force of the rear tunneling shield.

[0033] Furthermore, the excavation distance of the test ring is equal to the width of the segment ring;

[0034] The tunneling speeds at different stages of the tunneling test include:

[0035] The tunneling speed in the first quarter of the tunneling distance was gradually increased from 0 mm / min to 5 mm / min.

[0036] The tunneling speed for the remaining half of the mileage is any one of 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, or 30 mm / min.

[0037] In the final quarter of the tunnel, the tunneling speed was gradually reduced from 5 mm / min to 0 mm / min.

[0038] Furthermore, the formula for calculating the tunneling time is as follows:

[0039]

[0040] In the formula, T represents the tunneling time, L represents the tunneling distance of the test ring, and V5 and V 10 V 15 V 20 V 25 V 30 This indicates six different tunneling speeds.

[0041] Furthermore, the formula for calculating the tool penetration resistance is as follows:

[0042] F n后贯 =F n掘进 -F 静止

[0043] In the formula, F n后贯 F represents the respective penetration resistance of the rearward shield at different tunneling speeds. n掘进 F represents the contact force of the rearward tunneling shield at different tunneling speeds. 静止 This indicates the static contact force of the rearward-moving shield.

[0044] Furthermore, the calculation of the subsequent shield face support pressure based on the cutter penetration resistance at different tunneling speeds, combined with the shield-to-ground docking balance relationship, and the use of the subsequent shield face support pressure at different tunneling speeds to guide tunneling construction in order to maintain the stability of the preceding shield includes the following steps:

[0045] S31. Based on the cutter penetration resistance at different tunneling speeds, combined with the front surface area of ​​the subsequent shield cutter, calculate the subsequent shield penetration pressure at different tunneling speeds.

[0046] S32. Based on the balance relationship of shield docking in the ground, the support pressure of the subsequent shield face is calculated by combining the penetration pressure of the subsequent shield under different tunneling speeds.

[0047] S33. Guide tunneling construction according to the support pressure of the rear tunnel face at different tunneling speeds, so as to maintain the stability of the leading tunnel and ensure the safety of the rear tunneling machine.

[0048] Furthermore, the formula for calculating the subsequent shield penetration pressure is as follows:

[0049]

[0050] The formula for calculating the support pressure at the tunnel face of the subsequent shield tunneling is:

[0051] Q n后掌 =Q 先静 -Q n后贯

[0052] In the formula, Q n后贯 F represents the subsequent shield penetration pressure at different tunneling speeds. n后贯 Q represents the penetration resistance of the rearward shield at different tunneling speeds, S represents the surface area of ​​the front end of the rearward shield cutter, and Q represents the penetration resistance of the rearward shield cutter. n后掌 Q represents the support pressure at the tunnel face of the advancing shield at different tunneling speeds. 先静 This indicates the static earth pressure of the tunnel boring machine (TBM).

[0053] The beneficial effects of this invention are as follows:

[0054] 1) This invention designs a method for designing the support pressure of the tunnel face of a subsequent shield tunnel after underground docking. This method effectively solves the problem of parameter setting during near-field tunneling of the subsequent shield. The equilibrium formula is universally applicable to similar shield docking projects. Through penetration resistance tests of the near-ground stratum, the relationship between penetration resistance and tunneling speed at the docking position can be accurately reflected, thus obtaining the set value of the support pressure of the subsequent shield tunnel face, providing a theoretical basis for setting the tunneling parameters of the subsequent shield. This method for designing the support pressure of the tunnel face of a subsequent shield tunnel after underground docking is universally applicable to shield tunnels of different diameters. This invention is highly innovative and can be fully integrated into engineering practice, possessing significant potential for widespread application.

[0055] 2) By establishing a balance formula, this invention can theoretically calculate the support pressure of the shield tunnel face after underground docking, solving the problem of parameter setting during construction. Through the penetration resistance test of the adjacent strata, the penetration resistance of the tunnel lining at different speeds is obtained, providing a basis for solving the balance formula. In addition, the design method of shield tunnel face support pressure after underground docking of shield tunnels in this invention can provide a theoretical basis for tunneling construction parameters, greatly reducing the risks in the shield docking process and ensuring the safety of docking construction. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 This is a flowchart of a method for calculating the support pressure at the face of a subsequent shield tunneling machine, applicable to the underground docking of shield tunnels in high water pressure and permeable strata, according to an embodiment of the present invention.

[0058] Figure 2 This is a schematic diagram illustrating the principle of a method for calculating the support pressure at the face of a subsequent shield tunneling machine, applicable to ground docking in high water pressure and permeable strata, according to an embodiment of the present invention. Detailed Implementation

[0059] To further illustrate the various embodiments, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. These drawings are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementation methods and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0060] According to embodiments of the present invention, a method for calculating the support pressure of the tunnel face of a subsequent shield tunneling machine (TBM) during underground docking in high water pressure and highly permeable strata is provided. In high water pressure and highly permeable strata, significant mechanical coupling effects exist during the close-proximity tunneling of the subsequent TBM, which can easily lead to risks such as stratum instability, TBM displacement, and structural damage. Therefore, special attention needs to be paid to the support pressure of the TBM tunnel face. For example, rock strata may not require such high-precision support pressure because they possess high strength and self-stability.

[0061] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments, such as... Figures 1-2As shown in the figure, the method for calculating the support pressure of the tunnel face of a subsequent shield tunneling operation in ground-to-ground docking of shield tunnels in high water pressure and highly permeable strata according to an embodiment of the present invention includes the following steps:

[0062] S1. Based on the distance relationship between the subsequent shield tunneling and the preceding shield tunneling, and combined with the mechanical balance analysis of the shield tunneling docking process in the ground, establish the shield tunneling docking balance relationship in the ground to ensure that the additional stress generated by the subsequent shield tunneling is zero.

[0063] The step of establishing a ground-based shield docking equilibrium relationship based on the distance relationship between the subsequent shield tunneling and the preceding shield tunneling, combined with the mechanical equilibrium analysis of the shield docking process in the ground, in order to maintain the stability of the preceding shield tunneling, includes the following steps:

[0064] S11. Determine whether the proximity of the following shield tunneling to the preceding shield tunneling is greater than three times the shield diameter. If yes, ignore the impact of the following shield tunneling on the preceding shield tunneling. If no, execute S12.

[0065] S12. Based on the mechanical equilibrium relationship during the shield tunneling process, and combined with the state of the subsequent shield tunnel, establish the shield tunneling equilibrium formula to ensure that the additional stress generated by the subsequent shield tunneling is zero.

[0066] Specifically, when the distance between the subsequent shield tunneling and the preceding shield tunneling is greater than 3 times the shield diameter, based on Saint-Venant's principle of elasticity and previous research experience, the influence of the subsequent shield tunneling on the preceding shield tunneling can be considered negligible when the distance between the subsequent shield tunneling and the preceding shield tunneling exceeds 3 times the shield diameter.

[0067] When the distance between the advancing shield tunneling tunneling tunneling tunneling tunneling tunneling tunneling tunneling tunneling tunneling tunnels ...

[0068] Q 先静 =Q 后掌

[0069] Q 先静 =K0·γ·Z

[0070] In the formula, Q 先静 Q represents the static earth pressure (in kPa) of the tunnel boring machine. 后掌 K0 represents the earth pressure at the tunnel face during the subsequent shield tunneling (in kPa), K0 represents the coefficient of earth pressure at rest, and γ represents the unit weight of the fill (in kN / m³). 3 Z represents the burial depth of the bottom of the tunnel boring machine (in meters), and the most unfavorable working conditions are calculated based on this burial depth.

[0071] When the distance between the following shield tunneling machine and the preceding shield tunneling machine is less than 50m and both are in the process of tunneling, in order to maintain the stability of the preceding shield tunneling machine, the additional stress generated by the following shield tunneling machine on the preceding shield tunneling machine should be kept to zero. Therefore, measures should be taken to balance the forces generated by the following shield tunneling machine with the static earth pressure of the preceding shield tunneling machine, that is, to satisfy the equilibrium formula:

[0072] Q 先静 =Q 后掌 +Q 后贯

[0073] In the formula, Q 后贯 This indicates the penetration pressure of the subsequent shield tunneling (unit: kPa).

[0074] S2. Determine the tunneling speed of the subsequent shield tunneling machine in different tunneling test stages, and determine the tunneling time for each tunneling test stage; based on the penetration resistance test of the adjacent strata, calculate the cutter penetration resistance at different tunneling speeds;

[0075] The process of determining the tunneling speed of the shield tunneling machine at different tunneling test stages and determining the tunneling time for each tunneling test stage; and calculating the cutter penetration resistance at different tunneling speeds based on the penetration resistance test of the adjacent strata, includes the following steps:

[0076] S21. Select a ring of the adjacent docking section as the test ring, set the tunneling distance of the test ring and the tunneling speed of different tunneling test stages, and determine the tunneling time of each tunneling test stage according to the tunneling speed.

[0077] Specifically, a ring near the docking section is selected as the test ring. The strata of the test ring near the docking section are similar to those of the docking section, and the measured penetration resistance values ​​of the two are closer. The closer the test is to the docking section, the closer the obtained penetration resistance value is to the penetration resistance value of the docking section, which is more instructive. This is because the closer the test is to the strata and the more similar the burial depth, the closer the penetration resistance value obtained from the test is. The test can be conducted at a distance of 0-3 times the diameter of the shield tunnel from the docking point, and the closer the distance, the more accurate the result.

[0078] The test ring's excavation distance is equal to the width of the tunnel segment ring. For the first quarter of the test ring, the tunneling speed is gradually increased from 0 mm / min to 5 mm / min (i.e., the speed increases gradually from 0 mm / min to 5 mm / min, as this is done incrementally to ensure stable operation of the tunnel boring machine). The next half of the test ring is excavated at six different speeds: 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, and 30 mm / min. The final quarter of the test ring's excavation speed gradually decreases from 5 mm / min to 0 mm / min. The excavation time for the first and last quarter of the test ring is not part of the test scope and is not a primary concern. Generally, the speed gradually increases in the first quarter and gradually decreases in the last quarter. The formula for calculating the excavation time for the last half of the test ring is as follows:

[0079]

[0080] In the formula, T represents the tunneling time, L represents the tunneling distance of the test ring (ring segment width, in mm), and V5, V 10 V 15 V 20 V 25 V 30 This represents six different tunneling speeds (unit: mm / min);

[0081] The maximum normal tunneling speed of a tunnel boring machine is generally no more than 30 mm / min. Therefore, the test was conducted with six different tunneling speeds: 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, and 30 mm / min, as independent variables.

[0082] The tunneling time for each of the six different speed tunneling stages is taken as T, and the total mileage of the stage shall not exceed 1 / 2L. If it exceeds this, the tunneling time can be appropriately shortened.

[0083] S22. Before the test begins, record the static contact force of the rear tunnel boring machine when it is stationary, and conduct a tunneling test simulation based on the set tunneling speed and tunneling time.

[0084] S23. After the test ring tunneling is completed, record the contact force of the rear shield tunneling at different tunneling speeds, and calculate the cutter penetration resistance at different tunneling speeds based on the recorded contact force of the rear shield tunneling.

[0085] Specifically, following the above test procedure, after the test ring was completed, the contact force of the rear-moving shield tunneling was recorded at different tunneling speeds. Since the rear-moving shield machine only needs to overcome the penetration resistance generated by the cutter penetrating the ground to move from a static equilibrium state to a tunneling state, the calculation formula for the penetration resistance at different tunneling speeds is as follows:

[0086] F n后贯 =F n掘进 -F 静止

[0087] In the formula, F n后贯 F represents the penetration resistance of the rearward tunnel boring machine at different tunneling speeds (in kN). n掘进 F represents the contact force (in kN) of the tunneling shield at different tunneling speeds. 静止 This represents the static contact force of the rearward-moving shield (unit: kN).

[0088] S3. Based on the cutter penetration resistance at different tunneling speeds, and combined with the shield-to-ground docking balance relationship, calculate the support pressure of the subsequent shield face, and use the support pressure of the subsequent shield face at different tunneling speeds to guide the tunneling construction, so as to maintain the stability of the preceding shield.

[0089] The calculation of the subsequent shield face support pressure based on the cutter penetration resistance at different tunneling speeds, combined with the shield-to-ground docking balance relationship, and the use of the subsequent shield face support pressure at different tunneling speeds to guide tunneling construction in order to maintain the stability of the preceding shield includes the following steps:

[0090] S31. Based on the cutter penetration resistance at different tunneling speeds, combined with the front surface area of ​​the subsequent shield cutter, calculate the subsequent shield penetration pressure at different tunneling speeds.

[0091] Specifically, the formula for calculating the subsequent shield penetration pressure is as follows:

[0092]

[0093] In the formula, Q n后贯 F represents the subsequent shield penetration pressure (in MPa) at different tunneling speeds. n后贯 This represents the penetration resistance of the rearward shield at different tunneling speeds, where S represents the surface area of ​​the front end of the rearward shield cutter (unit: m²). 2 );

[0094] S32. Based on the balance relationship of shield docking in the ground, the support pressure of the subsequent shield face is calculated by combining the penetration pressure of the subsequent shield under different tunneling speeds.

[0095] Specifically, the formula for calculating the support pressure at the tunnel face of the subsequent shield tunneling is as follows:

[0096] Q n后掌 =Q 先静 -Q n后贯

[0097] In the formula, Q n后掌 Q represents the support pressure at the tunnel face of the advancing shield at different tunneling speeds (in MPa). 先静 This indicates the static earth pressure of the preceding shield tunneling;

[0098] S33. Guide tunneling construction according to the support pressure of the rear tunnel face at different tunneling speeds, so as to maintain the stability of the leading tunnel and ensure the safety of the rear tunneling machine.

[0099] In summary, by utilizing the above-mentioned technical solution of this invention, a method for designing the support pressure of the tunnel face after underground shield tunneling is completed is designed. This method effectively solves the problem of parameter setting during the near-field tunneling process of the subsequent shield tunnel. The equilibrium formula is universally applicable to similar shield tunneling projects. Through penetration resistance tests of the near-ground stratum, the relationship between penetration resistance and tunneling speed at the docking position can be accurately reflected, thereby obtaining the set value of the support pressure of the subsequent shield tunnel face, providing a theoretical basis for setting the tunneling parameters of the subsequent shield tunnel. This method for designing the support pressure of the tunnel face after underground shield tunneling is universally applicable to shield tunnels of different diameters. This invention is highly inventive and can be fully integrated into engineering practice, possessing significant potential for widespread application.

[0100] Meanwhile, by establishing a balance formula, this invention can theoretically calculate the support pressure of the tunnel face after underground docking, solving the problem of parameter setting during construction. Through the penetration resistance test of the adjacent strata, the penetration resistance of the tunnel lining at different speeds was obtained, providing a basis for solving the balance formula. In addition, the design method of support pressure of the tunnel face after underground docking of shield tunnels in this invention can provide a theoretical basis for tunneling construction parameters, greatly reducing the risks in the shield docking process and ensuring the safety of docking construction.

[0101] 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 within the protection scope of the present invention.

Claims

1. A method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in high-water-pressure, highly permeable strata, characterized in that... Includes the following steps: S1. Based on the distance relationship between the subsequent shield tunneling and the preceding shield tunneling, and combined with the mechanical balance analysis of the shield tunneling docking process in the ground, establish the shield tunneling docking balance relationship in the ground to ensure that the additional stress generated by the subsequent shield tunneling is zero. S2. Determine the tunneling speed of the subsequent shield tunneling machine in different tunneling test stages, and determine the tunneling time for each tunneling test stage; based on the penetration resistance test of the adjacent strata, calculate the cutter penetration resistance at different tunneling speeds; S3. Based on the cutter penetration resistance at different tunneling speeds, and combined with the shield docking balance relationship in the ground, calculate the support pressure of the subsequent shield face, and use the support pressure of the subsequent shield face at different tunneling speeds to guide the tunneling construction, so as to maintain the stability of the preceding shield.

2. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in high-water-pressure, highly permeable strata, as described in claim 1, is characterized in that... The process of establishing a ground-based shield docking equilibrium relationship based on the distance relationship between the subsequent shield tunneling and the preceding shield tunneling, combined with the mechanical equilibrium analysis of the shield docking process in the ground, to ensure that the additional stress generated by the subsequent shield tunneling is zero, includes the following steps: S11. Determine whether the proximity of the following shield tunneling to the preceding shield tunneling is greater than three times the shield diameter. If yes, ignore the impact of the following shield tunneling on the preceding shield tunneling. If no, execute S12. S12. Based on the mechanical equilibrium relationship during the shield tunneling process, and combined with the state of the subsequent shield tunnel, a shield tunneling equilibrium formula is established to ensure that the additional stress generated by the subsequent shield tunneling is zero.

3. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in high-water-pressure, highly permeable strata, as described in claim 2, is characterized in that... The aforementioned formula for establishing the shield-to-ground docking equilibrium based on the mechanical equilibrium relationship during the shield-to-ground docking process, combined with the state of the subsequent shield, to ensure that the additional stress generated by the subsequent shield's close-proximity excavation is zero includes: When the rear tunneling machine is stationary, in order to ensure that the additional stress generated by the rear tunneling machine on the preceding tunneling machine is zero, the force generated by the rear tunneling machine must be balanced with the static earth pressure of the preceding tunneling machine, so as to obtain the equilibrium formula for the ground docking of the tunneling machines in a stationary state. When the subsequent shield is in the tunneling state, in order to ensure that the additional stress generated by the subsequent shield tunneling on the preceding shield is zero, the force generated by the subsequent shield tunneling must be balanced with the static earth pressure of the preceding shield, so as to obtain the shield docking equilibrium formula in the tunneling state.

4. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in ground-to-ground docking of shield tunnels in high-water-pressure, highly permeable strata, as described in claim 3, is characterized in that... The expression for the shield tunneling ground docking equilibrium formula under static conditions is: Q 先静 =Q 后掌 Q 先静 =K0·γ·Z The expression for the shield tunneling ground docking equilibrium formula during tunneling is as follows: Q 先静 =Q 后掌 +Q 后贯 In the formula, Q 先静 Q represents the static earth pressure of the preceding shield tunneling machine. 后掌 The following values ​​represent the support pressure at the tunnel face of the rearward-moving shield, K0 represents the coefficient of earth pressure at rest, γ represents the unit weight of the fill, Z represents the bottom depth of the tunnel boring machine, and Q represents the support pressure at the tunnel face of the rearward-moving shield. 后贯 This indicates the pressure exerted by the subsequent tunnel boring machine (TBM) during penetration.

5. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in high water pressure and highly permeable strata, as described in claim 1, is characterized in that... The process of determining the tunneling speed of the shield tunneling machine at different tunneling test stages and determining the tunneling time for each tunneling test stage; and calculating the cutter penetration resistance at different tunneling speeds based on the penetration resistance test of the adjacent strata, includes the following steps: S21. Select a ring of the adjacent docking section as the test ring, set the tunneling distance of the test ring and the tunneling speed of different tunneling test stages, and determine the tunneling time of each tunneling test stage according to the tunneling speed. S22. Before the test begins, record the static contact force of the rear tunnel boring machine when it is stationary, and conduct a tunneling test simulation based on the set tunneling speed and tunneling time. S23. After the test ring tunneling is completed, record the contact force of the rear tunneling shield at different tunneling speeds, and calculate the cutter penetration resistance at different tunneling speeds based on the recorded contact force of the rear tunneling shield.

6. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in high-water-pressure, highly permeable strata, as described in claim 5, is characterized in that... The excavation distance of the test ring is equal to the width of the segment ring; The tunneling speeds at different stages of the tunneling test include: The tunneling speed in the first quarter of the tunneling distance was gradually increased from 0 mm / min to 5 mm / min. The tunneling speed for the remaining half of the mileage is any one of 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, or 30 mm / min. In the final quarter of the tunnel, the tunneling speed was gradually reduced from 5 mm / min to 0 mm / min.

7. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in ground-to-ground docking of shield tunnels in high-water-pressure, highly permeable strata, as described in claim 5, is characterized in that... The formula for calculating the tunneling time is: In the formula, T represents the tunneling time, L represents the tunneling distance of the test ring, and V5 and V 10 V 15 V 20 V 25 V 30 This indicates six different tunneling speeds.

8. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in high-water-pressure, highly permeable strata, as described in claim 5, is characterized in that... The formula for calculating the cutting tool penetration resistance is as follows: F n后贯 =F n掘进 -F 静止 In the formula, F n后贯 F represents the respective penetration resistance of the rearward shield at different tunneling speeds. n掘进 F represents the contact force of the rearward tunneling shield at different tunneling speeds. 静止 This indicates the static contact force of the rearward-moving shield.

9. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in ground-to-ground docking of shield tunnels in high-water-pressure, highly permeable strata, as described in claim 1, is characterized in that... The calculation of the subsequent shield face support pressure based on the cutter penetration resistance at different tunneling speeds, combined with the shield-to-ground docking balance relationship, and the use of the subsequent shield face support pressure at different tunneling speeds to guide tunneling construction in order to maintain the stability of the preceding shield includes the following steps: S31. Based on the cutter penetration resistance at different tunneling speeds, combined with the front surface area of ​​the subsequent shield cutter, calculate the subsequent shield penetration pressure at different tunneling speeds. S32. Based on the balance relationship of shield docking in the ground, the support pressure of the subsequent shield face is calculated by combining the penetration pressure of the subsequent shield under different tunneling speeds. S33. Guide tunneling construction according to the support pressure of the rear tunnel face at different tunneling speeds, so as to maintain the stability of the leading tunnel and ensure the safety of the rear tunneling machine.

10. The method for calculating the support pressure at the tunnel face of a subsequent shield tunneling operation in ground-to-ground docking of shield tunnels in high-water-pressure, highly permeable strata, as described in claim 9, is characterized in that... The formula for calculating the subsequent shield penetration pressure is as follows: The formula for calculating the support pressure at the tunnel face of the subsequent shield tunneling is: Q n后掌 =Q 先静 -Q n后贯 In the formula, Q n后贯 F represents the subsequent shield penetration pressure at different tunneling speeds. n后贯 Q represents the penetration resistance of the rearward shield at different tunneling speeds, S represents the surface area of ​​the front end of the rearward shield cutter, and Q represents the penetration resistance of the rearward shield cutter. n后掌 Q represents the support pressure at the tunnel face of the advancing shield at different tunneling speeds. 先静 This indicates the static earth pressure of the tunnel boring machine (TBM).

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