Method for calculating support pressure of backward shield tunnel face suitable for butt joint in shield ground of high-water-pressure permeable stratum

Abstract

The invention relates to the technical field of shield tunnel engineering, and discloses a backward shield tunnel face support pressure calculation method suitable for high-water-pressure permeable stratum shield in-ground butt joint, which comprises the following steps of: establishing a shield in-ground butt joint balance relation in combination with mechanical equilibrium analysis in a shield in-ground butt joint process; calculating the penetration resistance of the cutter at different tunneling speeds based on a butt joint adjacent stratum penetration resistance test; the supporting pressure of the backward shield tunnel face is calculated, and tunneling construction is guided through the supporting pressure of the backward shield tunnel face at different tunneling speeds. According to the method, the problem of parameter setting in the proximity tunneling process of the following shield can be effectively solved, the balance formula has universality for similar shield butt joint projects, the corresponding relation between the penetration resistance and the tunneling speed of the butt joint position can be truly reflected through the penetration resistance test of the near ground layer, and the method has the advantages of being high in practicability and the like. And the set value of the supporting pressure of the tunnel face of the subsequent shield is obtained, and a theoretical basis is provided for setting tunneling parameters of the subsequent shield.

Description

Technical Field

[0001] The present invention relates to the technical field of shield tunnel engineering, and in particular, to a method for calculating the support pressure of the face of a trailing shield suitable for shield in-situ docking in a highly water-pressure permeable stratum. Background Art

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

[0003] At present, during the implementation of the shield in-situ docking method, the leading shield inevitably has to be in a shutdown state, and the slurry chamber is already filled with mortar. During the close-proximity tunneling of the trailing shield, unreasonable support pressure and tunneling speed will inevitably have a negative impact on the leading and trailing shield machines and their internal structures. Therefore, a reasonable method for setting the support pressure of the trailing shield needs to be given, and the tunneling speed needs to be controlled within a reasonable range to ensure the safety of the docking construction.

[0004] Publication No. CN112307547A discloses a method for designing the support pressure of a tunnel face, which uses numerical calculation software to continuously iterate according to the specified target safety factor and the initial value of the support pressure until the calculated safety factor is the same as the target safety factor. At this time, the corresponding support pressure is the target value. However, it cannot solve the problem of the additional load of the trailing shield on the leading shield in the in-situ docking scenario, and has certain limitations.

[0005] Although a large amount of work has been done in the existing published research, the following technical problems cannot be completely solved:

[0006] 1. During the shield in-situ docking process, it is difficult to master the additional stress situation generated by the close-proximity tunneling of the trailing shield on the leading shield.

[0007] 2. During the shield tunneling process, the penetration resistance value of the cutter cannot be estimated.

[0008] 3. During the shield in-situ docking process, there is no clear calculation basis for the construction parameters of the close-proximity tunneling of the trailing shield.

[0009] For the problems in the related technology, no effective solution has been proposed yet. Summary of the Invention

[0010] In view of the problems in the related art, the present invention proposes a method for calculating the support pressure of the face of the trailing shield applicable to the in - situ docking of shields in highly water - pressured pervious strata, so as to overcome the above - mentioned technical problems existing in the existing related technologies.

[0011] The present invention is divided into two stages based on the distance between the leading shield and the trailing shield. When the distance in the first stage is large, the support pressure of the face of the trailing shield is calculated by the conventional method. After the distance is reduced to a certain value in the second stage, the mechanical equilibrium relationship in the process of adjacent tunneling of the shield is analyzed, and an equilibrium formula for calculating the support pressure of the face of the trailing shield is given; based on the force - bearing characteristics of the shield cutter during tunneling, a calculation formula and test method for the penetration resistance of the cutter are given; through the penetration resistance test of the shield tunneling in the strata near the docking section, the penetration resistance values of the cutters of the trailing shield at different tunneling speeds are calculated, further guiding the design of the support pressure of the face of the trailing shield. The design method can be actually 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 of the face of the trailing shield applicable to the in - situ docking of shields in highly water - pressured pervious strata, comprising the following steps:

[0014] S1. According to the distance relationship between the adjacent tunneling of the trailing shield and the leading shield, combined with the mechanical equilibrium analysis in the process of in - situ docking of the shield, establish the in - situ docking equilibrium relationship of the shield to ensure that the additional stress generated by the adjacent tunneling of the trailing shield is zero;

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

[0016] S3. Based on the penetration resistance of the cutter at different tunneling speeds, combined with the in - situ docking equilibrium relationship of the shield, calculate the support pressure of the face of the trailing shield, and use the support pressure of the face of the trailing shield at different tunneling speeds to guide the tunneling construction to maintain the stability of the leading shield.

[0017] Further, the step of establishing the in - situ docking equilibrium relationship of the shield according to the distance relationship between the adjacent tunneling of the trailing shield and the leading shield, combined with the mechanical equilibrium analysis in the process of in - situ docking of the shield to ensure that the additional stress generated by the adjacent tunneling of the trailing shield is zero includes the following steps:

[0018] S11. Judge whether the distance between the adjacent tunneling of the trailing shield and the leading shield is greater than three times the shield diameter. If so, ignore the influence of the trailing shield on the leading shield. If not, execute S12;

[0019] S12. Based on the mechanical equilibrium relationship during the in - situ docking of the shield tunneling machines, establish the in - situ docking equilibrium formula of the shield tunneling machines in combination with the state of the trailing shield tunneling machine, so as to ensure that the additional stress generated by the trailing shield tunneling machine during close - proximity tunneling is zero.

[0020] Furthermore, the establishment of the in - situ docking equilibrium formula of the shield tunneling machines based on the mechanical equilibrium relationship during the in - situ docking of the shield tunneling machines and in combination with the state of the trailing shield tunneling machine to ensure that the additional stress generated by the trailing shield tunneling machine during close - proximity tunneling is zero includes:

[0021] When the trailing shield tunneling machine is in a static state, in order to ensure that the additional stress generated by the trailing shield tunneling machine on the leading shield tunneling machine is zero, it is necessary to balance the force generated by the trailing shield tunneling machine with the static earth pressure of the leading shield tunneling machine, and obtain the in - situ docking equilibrium formula of the shield tunneling machines in the static state;

[0022] When the trailing shield tunneling machine is in the tunneling state, in order to ensure that the additional stress generated by the trailing shield tunneling machine during tunneling on the leading shield tunneling machine is zero, it is necessary to balance the force generated by the trailing shield tunneling machine during tunneling with the static earth pressure of the leading shield tunneling machine, and obtain the in - situ docking equilibrium formula of the shield tunneling machines in the tunneling state.

[0023] Furthermore, the expression of the in - situ docking equilibrium formula of the shield tunneling machines in the static state is:

[0024] Q 先静 =Q 后掌

[0025] Q 先静 =K0·γ·Z

[0026] The expression of the in - situ docking equilibrium formula of the shield tunneling machines in the tunneling state is:

[0027] Q 先静 =Q 后掌 +Q 后贯

[0028] In the formula, Q 先静 represents the static earth pressure of the leading shield tunneling machine, Q 后掌 represents the support pressure of the face of the trailing shield tunneling machine, K0 represents the coefficient of static earth pressure, γ represents the unit weight of the fill soil, Z represents the buried depth of the bottom of the shield tunneling machine, and Q 后贯 represents the penetration pressure of the trailing shield tunneling machine.

[0029] Furthermore, the steps of determining the tunneling speed of the trailing shield tunneling machine in different tunneling test stages and determining the tunneling time of each tunneling test stage; calculating the cutter penetration resistance at different tunneling speeds based on the penetration resistance test of the strata near the docking include the following:

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

[0031] S22. Before the start of the test, record the static contact force of the trailing shield when it is in a static state, and conduct a tunneling test simulation according to the set tunneling speed and tunneling time.

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

[0033] Furthermore, the tunneling distance of the test ring is the width of the segment ring.

[0034] The tunneling speeds in different tunneling test stages include:

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

[0036] Subsequently, the tunneling speed in the middle half of the distance is any one of 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, and 30 mm / min.

[0037] The tunneling speed in the last quarter of the distance is slowly decreased uniformly from 5 mm / min to 0 mm / min.

[0038] Furthermore, the calculation formula for the tunneling time is:

[0039]

[0040] In the formula, T represents the tunneling time, L represents the tunneling distance of the test ring, and V5, V 10 , V 15 , V 20 , V 25 , V 30 represent 6 different tunneling speeds.

[0041] Furthermore, the calculation formula for the cutter penetration resistance is:

[0042] F n后贯 = F n掘进 - F 静止

[0043] In the formula, F n后贯 represents the penetration resistance of the trailing shield at different tunneling speeds respectively, F n掘进 represents the tunneling contact force of the trailing shield at different tunneling speeds respectively, and F 静止 represents the static contact force of the trailing shield.

[0044] Further, based on the cutter penetration resistance at different tunneling speeds, the support pressure of the rear shield face is calculated by combining with the shield in-situ docking balance relationship, and the tunneling construction is guided by the support pressure of the rear shield face at different tunneling speeds to maintain the stability of the front shield, including the following steps:

[0045] S31. According to the cutter penetration resistance at different tunneling speeds, combining with the surface area of the front end of the cutters of the rear shield, calculate the penetration pressure of the rear shield at different tunneling speeds;

[0046] S32. Based on the shield in-situ docking balance relationship, calculate the support pressure of the rear shield face by combining with the penetration pressure of the rear shield at different tunneling speeds;

[0047] S33. Guide the tunneling construction according to the support pressure of the rear shield face at different tunneling speeds to maintain the stability of the front shield and ensure the safety of the rear shield machine.

[0048] Further, the calculation formula for the penetration pressure of the rear shield is:

[0049]

[0050] The calculation formula for the support pressure of the rear shield face is:

[0051] Q n后掌 =Q 先静 -Q n后贯

[0052] In the formula, Q n后贯 represents the penetration pressure of the rear shield at different tunneling speeds respectively, F n后贯 represents the penetration resistance of the rear shield at different tunneling speeds respectively, S represents the sum of the surface areas of the front ends of the cutters of the rear shield, Q n后掌 represents the support pressure of the rear shield face at different tunneling speeds respectively, and Q 先静 represents the static earth pressure of the front shield.

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

[0054] 1) The present invention designs a method for designing the support pressure of the rear shield face during shield in-situ docking, which can effectively solve the problem of parameter setting during the close-proximity tunneling of the rear shield. For similar shield docking projects, the balance formula is universal. Through the penetration resistance test of the near-ground strata, the corresponding relationship between the penetration resistance at the docking position and the tunneling speed can be truly reflected, and then the set value of the support pressure of the rear shield face can be obtained, providing a theoretical basis for the parameter setting of the rear shield tunneling. This method for designing the support pressure of the rear shield face during shield in-situ docking is universal for shield tunnels with different diameters. The present invention has strong creativity and can be fully integrated into engineering practice, with great significance for popularization.

[0055] 2) By establishing a balance formula, the present invention can theoretically calculate the support pressure of the shield face after in-situ docking, solving the problem of parameter setting during the construction process; through the penetration resistance test of the formation near the docking, the penetration resistance of the tool at different speeds is obtained, providing a basis for solving the balance formula; in addition, the design method of the support pressure of the shield face of the following shield after in-situ docking of the present invention can provide a theoretical basis for the tunneling construction parameters, greatly reducing the risk during the shield docking process and ensuring the safety of the docking construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0057] Figure 1 is a flowchart of a method for calculating the support pressure of the shield face of the following shield applicable to in-situ docking of a shield in a highly water-pressure permeable formation according to an embodiment of the present invention;

[0058] Figure 2 is a schematic diagram of the principle of a method for calculating the support pressure of the shield face of the following shield applicable to in-situ docking of a shield in a highly water-pressure permeable formation according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] To further illustrate the embodiments, the present invention provides drawings, which are part of the disclosure of the present invention. They 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 contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention. The components in the drawings are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0060] According to an embodiment of the present invention, a method for calculating the support pressure of the shield face of the following shield applicable to in-situ docking of a shield in a highly water-pressure permeable formation is provided. In a highly water-pressure permeable formation, there is a significant mechanical coupling effect during the near-proximity tunneling of the following shield, which is prone to risks such as formation instability, shield deviation, and structural damage. Therefore, special attention needs to be paid to the support pressure of the shield face. For example, the rock formation may not require such a high-precision support pressure because of its high strength and self-stability.

[0061] The present invention will be further described below in conjunction with the drawings and specific embodiments, as Figure 1 - Figure 2As shown, the calculation method for the support pressure of the face of the trailing shield applicable to the shield in - situ docking in high - water - pressure pervious strata according to the embodiments of the present invention includes the following steps:

[0062] S1. According to the distance relationship between the trailing shield's close - range tunneling and the leading shield, combined with the mechanical equilibrium analysis during the shield in - situ docking process, establish the shield in - situ docking equilibrium relationship to ensure that the additional stress generated by the trailing shield's close - range tunneling is zero;

[0063] Among them, the steps of establishing the shield in - situ docking equilibrium relationship according to the distance relationship between the trailing shield's close - range tunneling and the leading shield, combined with the mechanical equilibrium analysis during the shield in - situ docking process to maintain the stability of the leading shield include the following steps:

[0064] S11. Judge whether the distance between the trailing shield's close - range tunneling and the leading shield is greater than three times the shield diameter. If so, ignore the influence of the trailing shield on the leading shield. If not, execute S12;

[0065] S12. Based on the mechanical equilibrium relationship during the shield in - situ docking process, combined with the state of the trailing shield, establish the shield in - situ docking equilibrium formula to ensure that the additional stress generated by the trailing shield's close - range tunneling is zero;

[0066] Specifically, when the distance between the trailing shield's close - range tunneling and the leading shield is greater than 3 times the shield diameter, according to the Saint - Venant principle of elasticity and the research experience of predecessors, when the distance between the trailing shield and the leading shield exceeds 3 times the shield diameter, the influence of the trailing shield on the leading shield can be considered negligible;

[0067] When the distance between the trailing shield's close - range tunneling and the leading shield is less than 3 times the shield diameter and the trailing shield is in a static state, to maintain the stability of the leading shield, it should be ensured that the additional stress generated by the trailing shield on the leading shield is 0. Therefore, measures should be taken to make the force generated by the trailing shield balance with the static earth pressure of the leading shield, that is, to satisfy the equilibrium formula:

[0068] Q 先静 =Q 后掌

[0069] Q 先静 =K0·γ·Z

[0070] In the formula, Q 先静 represents the static earth pressure of the leading shield (unit: KPa), Q 后掌 represents the support pressure of the face of the trailing shield (unit: KPa), K0 represents the coefficient of static earth pressure, γ represents the unit weight of the fill soil (unit: KN / m 3 ³), Z represents the buried depth at the bottom of the shield machine (unit: m), and the most unfavorable working condition is calculated according to this buried depth;

[0071] When the distance between the trailing shield tunneling closely and the leading shield is less than 50 m and the trailing shield is in the tunneling state, to maintain the stability of the leading shield, the additional stress generated by the trailing shield tunneling on the leading shield should be ensured to be 0. Therefore, measures should be taken to balance the force generated by the trailing shield tunneling with the static earth pressure of the leading shield, that is, to satisfy the equilibrium formula:

[0072] Q 先静 =Q 后掌 +Q 后贯

[0073] In the formula, Q 后贯 represents the penetration pressure of the trailing shield (unit: KPa);

[0074] S2. Determine the tunneling speed of the trailing shield in different tunneling test stages, and determine the tunneling time of each tunneling test stage; based on the penetration resistance test of the approaching formation for docking, calculate the penetration resistance of the cutter at different tunneling speeds;

[0075] Among them, the steps of determining the tunneling speed of the trailing shield in different tunneling test stages, determining the tunneling time of each tunneling test stage, and calculating the penetration resistance of the cutter at different tunneling speeds based on the penetration resistance test of the approaching formation for docking include the following:

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

[0077] Specifically, select a certain ring in the adjacent docking section as the test ring. The formation where the test ring in the adjacent docking section is located is similar to the formation in the docking section, and the measured values of the penetration resistance of the two are closer. If the test is carried out closer to the docking section in the adjacent docking section, the obtained penetration resistance value is closer to the penetration resistance value of the docking section, which is more instructive. Because the closer to the formation where it is located, the more similar the buried depth is, so the obtained penetration resistance value is closer. The range can be anywhere within (0 - 3 times the shield diameter) from the docking position for the test, and the closer the distance, the more accurate.

[0078] The tunneling distance of the test ring is the width of the segment ring. In the first quarter of the mileage, the tunneling speed of the shield machine is slowly increased from 0 mm / min to 5 mm / min at a uniform speed (that is, the tunneling speed will gradually increase from 0 mm / min to 5 mm / min. Since the tunneling speed increases bit by bit and will not reach 5 mm / min directly, the first quarter of the mileage is used for speed increase to ensure the stable operation of the shield machine). Subsequently, in the middle half of the mileage, the tunneling is carried out at 6 different tunneling speeds of 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, and 30 mm / min. Finally, in the last quarter of the mileage, the tunneling speed is slowly decreased from 5 mm / min to 0 mm / min at a uniform speed. The tunneling time in the first quarter and the last quarter of the mileage does not belong to the test range and is not a key requirement. Generally, the speed is gradually increased in the first quarter of the mileage and gradually decreased in the last quarter of the mileage. The calculation formula for the tunneling time of the middle half of the mileage 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 (the width of the segment ring, in mm), V5, V 10 , V 15 , V 20 , V 25 , V 30 represent 6 different tunneling speeds (in mm / min);

[0081] The maximum normal tunneling speed of the shield machine generally does not exceed 30 mm / min. Therefore, the test is divided into 6 different tunneling speeds of 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, and 30 mm / min as the test independent variables;

[0082] For each of the 6 different speed tunneling stages, the tunneling time taken is T, and the total mileage of this stage does not exceed 1 / 2L. If it exceeds, the tunneling time can be appropriately shortened;

[0083] S22. Before the test starts, record the static contact force of the trailing shield when it is in a static state, and conduct a tunneling test simulation according to the set tunneling speed and tunneling time;

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

[0085] Specifically, during tunneling according to the above test procedure, after the test ring propulsion is completed, record the contact force of the trailing shield tunneling at different tunneling speeds. Since when the trailing shield machine changes from a static equilibrium state to a tunneling state, it only needs to overcome the penetration resistance generated by the cutter penetrating the formation to move, 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 represents the penetration resistance of the trailing shield at different tunneling speeds (unit: kN), F n掘进 represents the contact force of the trailing shield tunneling at different tunneling speeds (unit: kN), and F 静止 represents the static contact force of the trailing shield (unit: kN);

[0088] S3. Based on the cutter penetration resistance at different tunneling speeds, calculate the support pressure of the trailing shield face in combination with the balance relationship of the shield in-situ docking, and use the support pressure of the trailing shield face at different tunneling speeds to guide the tunneling construction to maintain the stability of the leading shield;

[0089] Among them, the step of calculating the support pressure of the trailing shield face based on the cutter penetration resistance at different tunneling speeds, combining the balance relationship of the shield in-situ docking, and using the support pressure of the trailing shield face at different tunneling speeds to guide the tunneling construction to maintain the stability of the leading shield includes the following steps:

[0090] S31. According to the cutter penetration resistance at different tunneling speeds, combine the surface area of the front end of the trailing shield cutter and calculate the penetration pressure of the trailing shield at different tunneling speeds;

[0091] Specifically, the calculation formula for the penetration pressure of the trailing shield is:

[0092]

[0093] In the formula, Q n后贯 represents the penetration pressure of the trailing shield at different tunneling speeds (unit: MPa), F n后贯 represents the penetration resistance of the trailing shield at different tunneling speeds, and S represents the sum of the surface areas of the front ends of the trailing shield cutters (unit: m 2 ²);

[0094] S32. Based on the balance relationship of the shield in-situ docking, combine the penetration pressure of the trailing shield at different tunneling speeds and calculate the support pressure of the trailing shield face;

[0095] Specifically, the calculation formula for the support pressure of the trailing shield face is:

[0096] Q n后掌 = Q 先静 -Q n后贯

[0097] In the formula, Q n后掌 represents the support pressure of the face of the trailing shield at respective different tunneling speeds (unit: MPa), and Q 先静 represents the earth pressure at rest of the leading shield;

[0098] S33. Guide the tunneling construction according to the support pressure of the face of the trailing shield at different tunneling speeds to maintain the stability of the leading shield and ensure the safety of the trailing shield machine.

[0099] In summary, by means of the above technical solutions of the present invention, the present invention designs a method for designing the support pressure of the face of the trailing shield in the in-situ docking of shield tunneling, which can effectively solve the problem of parameter setting during the close-proximity tunneling of the trailing shield. For similar shield docking projects, the balance formula is universal. Through the penetration resistance test of the near-proximity strata, the corresponding relationship between the penetration resistance at the docking position and the tunneling speed can be truly reflected, and then the set value of the support pressure of the face of the trailing shield can be obtained, providing a theoretical basis for the parameter setting of the trailing shield tunneling. The method for designing the support pressure of the face of the trailing shield in the in-situ docking of shield tunneling is universal for shield tunnels with different diameters. The present invention has strong creativity and can be fully integrated into engineering practice, having great popularization significance.

[0100] At the same time, through the establishment of the balance formula, the present invention can theoretically calculate the support pressure of the face of the trailing shield in the in-situ docking, solving the problem of parameter setting during the construction process; through the penetration resistance test of the strata near the docking, the penetration resistance of the tool at different speeds is obtained, providing a basis for solving the balance formula; in addition, the method for designing the support pressure of the face of the trailing shield in the in-situ docking of the present invention can provide a theoretical basis for the tunneling construction parameters, greatly reducing the risks during the shield docking process and ensuring the safety of the docking construction.

[0101] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A calculation method for the support pressure of the face of the trailing shield applicable to the shield in - medium docking in highly permeable strata under high water pressure, characterized in that, It includes the following steps: S1. According to the distance relationship between the subsequent shield tunneling in close proximity and the preceding shield, combined with the mechanical equilibrium analysis during the shield in-situ docking process, establish the shield in-situ docking equilibrium relationship to ensure that the additional stress generated by the subsequent shield tunneling in close proximity is zero; S2. Determine the tunneling speed of the subsequent shield in different tunneling test stages and determine the tunneling time for each tunneling test stage; Based on the penetration resistance test of the strata near the docking, calculate the cutter penetration resistance at different tunneling speeds; S3. Based on the cutter penetration resistance at different tunneling speeds, combined with the shield in-situ docking equilibrium relationship, calculate the support pressure of the face of the subsequent shield, and use the support pressure of the face of the subsequent shield at different tunneling speeds to guide the tunneling construction to maintain the stability of the preceding shield.

2. The calculation method of the support pressure of the face of the trailing shield applicable to the shield in - situ butt - joint in highly permeable strata under high water pressure, as claimed in claim 1, is characterized in that, The establishment of the shield in-situ docking equilibrium relationship according to the distance relationship between the subsequent shield tunneling in close proximity and the preceding shield, combined with the mechanical equilibrium analysis during the shield in-situ docking process to ensure that the additional stress generated by the subsequent shield tunneling in close proximity is zero includes the following steps: S11. Judge whether the distance between the subsequent shield tunneling in close proximity and the preceding shield is greater than three times the shield diameter. If so, ignore the influence of the subsequent shield on the preceding shield. If not, execute S12; S12. Based on the mechanical equilibrium relationship during the shield in-situ docking process, combined with the state of the subsequent shield, establish the shield in-situ docking equilibrium formula to ensure that the additional stress generated by the subsequent shield tunneling in close proximity is zero.

3. The calculation method of the support pressure of the face of the trailing shield applicable to the shield in - medium docking in a high - water - pressure pervious stratum according to claim 2, characterized in that, The establishment of the shield in-situ docking equilibrium formula based on the mechanical equilibrium relationship during the shield in-situ docking process, combined with the state of the subsequent shield to ensure that the additional stress generated by the subsequent shield tunneling in close proximity is zero includes: When the subsequent shield is in a stationary state, to ensure that the additional stress generated by the subsequent shield on the preceding shield is zero, it is necessary to balance the force generated by the subsequent shield with the static earth pressure of the preceding shield to obtain the shield in-situ docking equilibrium formula in the stationary state; When the subsequent shield is in the tunneling state, to ensure that the additional stress generated by the subsequent shield tunneling on the preceding shield is zero, it is necessary to balance the force generated by the subsequent shield tunneling with the static earth pressure of the preceding shield to obtain the shield in-situ docking equilibrium formula in the tunneling state.

4. A method for calculating the support pressure of the face of the trailing shield applicable to the shield in - situ docking in highly permeable strata under high water pressure, characterized in that, The expression of the shield in-situ docking equilibrium formula in the stationary state is: Q 先静 = Q 后掌 Q 先静 = K0·γ·Z The expression of the shield in-situ docking equilibrium formula in the tunneling state is: Q 先静 = Q 后掌 + Q 后贯 Wherein, Q 先静 represents the static earth pressure of the preceding shield, Q 后掌 represents the face support pressure of the following shield, K0 represents the coefficient of static earth pressure, γ represents the unit weight of the fill, Z represents the buried depth at the bottom of the shield machine, and Q 后贯 represents the penetration pressure of the following shield.

5. The calculation method for the support pressure of the face of the trailing shield applicable to the shield in - medium docking in a highly water - pressure permeable stratum according to claim 1, characterized in that, The determination of the tunneling speed of the subsequent shield in different tunneling test stages and the determination of the tunneling time for each tunneling test stage; Based on the penetration resistance test of the strata near the docking, the calculation of the cutter penetration resistance at different tunneling speeds includes the following steps: S21. Select a certain ring in the section near the docking as the test ring, set the tunneling distance of the test ring and the tunneling speeds in different tunneling test stages, and determine the tunneling time for each tunneling test stage according to the tunneling speed; S22. Before the test starts, record the static contact force of the subsequent shield when it is in a stationary state, and conduct a tunneling test simulation according to the set tunneling speed and tunneling time; S23. After the tunneling of the test ring is completed, record the tunneling contact force of the subsequent shield at different tunneling speeds, and calculate the cutter penetration resistance at different tunneling speeds according to the recorded tunneling contact force of the subsequent shield.

6. The calculation method of the support pressure of the face of the trailing shield applicable to the shield in-situ butt joint in a highly water-permeable stratum under high water pressure according to claim 5, characterized in that The driving distance of the test ring is the width of the segment ring; The driving speeds at different driving test stages include: The driving speed in the first quarter of the driving distance is uniformly and slowly increased from 0 mm / min to 5 mm / min; Subsequently, the driving speed in the middle half of the driving distance is any one of 5 mm / min, 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, and 30 mm / min; The driving speed in the last quarter of the driving distance is uniformly and slowly decreased from 5 mm / min to 0 mm / min.

7. A method for calculating the support pressure of the face of the trailing shield applicable to the shield in - medium docking in highly permeable strata under high water pressure, characterized in that, The calculation formula for the driving time is: Wherein, T represents the tunneling time, L represents the tunneling distance of the test ring, V5, V 10 , V 15 , V 20 , V 25 , V 30 represent six different tunneling speeds.

8. The calculation method of the support pressure of the face of the trailing shield applicable to the shield in - medium docking in highly permeable strata under high water pressure, characterized in that, The calculation formula for the cutter penetration resistance is: F n后贯 = F n掘进 -F 静止 Where, F n后贯 represents the penetration resistance of the trailing shield at respective different tunneling speeds, F n掘进 represents the tunneling contact force of the trailing shield at respective different tunneling speeds, and F 静止 represents the static contact force of the trailing shield.

9. The calculation method of the support pressure of the face of the trailing shield applicable to the shield in - medium docking in a highly water - pressure permeable stratum according to claim 1, characterized in that, Based on the cutter penetration resistance at different driving speeds, combining with the shield tunnel mid - alignment balance relationship to calculate the support pressure of the face of the trailing shield, and using the support pressure of the face of the trailing shield at different driving speeds to guide the tunneling construction to maintain the stability of the leading shield includes the following steps: S31. According to the cutter penetration resistance at different driving speeds, combining with the surface area at the front end of the cutters of the trailing shield to calculate the penetration pressure of the trailing shield at different driving speeds; S32. Based on the shield tunnel mid - alignment balance relationship, combining with the penetration pressure of the trailing shield at different driving speeds to calculate the support pressure of the face of the trailing shield; S33. According to the support pressure of the face of the trailing shield at different driving speeds to guide the tunneling construction to maintain the stability of the leading shield and ensure the safety of the trailing shield machine.

10. The calculation method of the support pressure of the face of the trailing shield applicable to the shield in - situ docking in highly permeable strata under high water pressure, characterized in that, The calculation formula for the penetration pressure of the trailing shield is: The calculation formula for the support pressure of the face of the trailing shield is: Q n后掌 = Q 先静 -Q n后贯 Where, Q n后贯 represents the penetration pressure of the trailing shield at respective different tunneling speeds, F n后贯 represents the penetration resistance of the trailing shield at respective different tunneling speeds, S represents the sum of the front surface areas of the cutters of the trailing shield, Q n后掌 represents the face support pressure of the trailing shield at respective different tunneling speeds, Q 先静 represents the earth pressure at rest of the leading shield.

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