Shield tunnel anchoring type sealing gasket leakage risk prediction method and system

Abstract

The invention discloses a shield tunnel anchoring type sealing gasket leakage risk prediction method and system, and the method comprises the steps: determining a sealing gasket leakage risk index R according to the acting stress F of underground water pressure at a sealing gasket joint, the aging coefficient P of a sealing gasket, and the corrosion coefficient alpha of duct piece concrete at the sealing gasket joint, and R = F * alpha * P; the limit waterproof capacity ZJ of the sealing gasket is determined; and comparing the leakage risk index of the sealing gasket with the ultimate waterproof capability, if R is less than or equal to ZJ, early warning, and taking waterproof measures. Leakage early warning can be given out in time, so that the leakage risk of the sealing gasket is predicted in advance, the service life of a tunnel is prolonged, and economic losses caused by tunnel repairing are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel engineering safety, and specifically to a method and system for predicting the leakage risk of an anchor-type gasket in a shield tunnel. Background Art

[0002] As a kind of transportation infrastructure connecting urban areas, tunnels play an important role in regional economic development, reducing road occupation, and traffic diversion. Shield tunnels are widely used in cross-river, cross-sea tunnels and urban subways due to their good construction safety and efficiency. Shield tunnels are usually assembled piece by piece and ring by ring from precast segments, and there are many joints at the connections. During the tunnel construction or operation stage, the joints are affected by factors such as seismic loads, train loads, groundwater pressure, and construction errors, and are the main leakage sites. Serious joint leakage problems will endanger the safety performance of the tunnel, affect the service life of the tunnel, and cause a large amount of economic losses.

[0003] At present, there are still some deficiencies in solving the joint leakage problem. For example, in the invention patent with the patent publication number CN115356187A, the area with the already occurred leakage risk is corrected by judging the leakage risk of the shield tunnel joint. However, it does not predict the upcoming leakage risk of the tunnel and take preventive measures in advance to reduce the economic losses caused by leakage. This patent also measures the opening amount and misalignment amount of the gasket through optical fiber technology, and then substitutes them into the fitting formula to measure the contact stress. However, in actual engineering, it is impossible to measure the opening amount and misalignment amount between different gaskets through optical fiber after the gasket is extruded, and the long-term change of the opening amount and misalignment amount of the gasket is weak, and the gasket is easily deformed by extrusion, making it difficult to measure the opening amount and misalignment amount, and it is difficult to implement. Due to the complex change of groundwater, the stress change on the gasket at the joint is complex. This patent only calculates the groundwater pressure acting on the shield tunnel segment joint through the shield tunnel and the groundwater depth, and does not have the function of coping with the change of groundwater pressure.

[0004] In the invention patent with the patent publication number CN116448354A, the research adopts the mutual cooperation of the lateral displacement cyclic loading mechanism and the control mechanism to simulate the fatigue effect of sea tides on the gasket material, obtain the influence of tidal action on the deformation of the shield tunnel segment joint, and at the same time, by accelerating the aging of the gasket, consider the influence of sea area corrosion on the durability of the joint material. However, for the influence of the corrosion performance of the shield tunnel segment at the joint under different environmental factors on the leakage risk of the gasket, no corresponding safety evaluation coefficient is provided, and it is impossible to cope with the risk assessment under various environmental changes.

[0005] Regarding the waterproofing at the joints of shield tunnel segments, the traditional method is to paste the gasket on the corresponding segment grooves and rely on the contact stress generated by the rebound compression of the gasket itself for waterproofing. For example, in the invention patent with the publication number CN114526097A, by optimizing the shape, size, and position of the through holes of the gasket, a structure with better stability and waterproof performance is obtained, which ensures the waterproof performance between gaskets to a certain extent. However, the bonding quality of traditional gaskets is affected by human factors, construction factors, and bonding materials, and there is a phenomenon of gasket debonding. In addition, there are potential leakage paths between the gasket and the segment grooves.

[0006] During the construction or use of shield tunnels, the joint parts are most prone to leakage risks. It is difficult to measure the opening and misalignment amounts of gaskets in actual projects. The stress changes generated by groundwater pressure on the gaskets at the joints are complex, and there are many factors affecting the leakage risks at the joint parts. In the case of specific tunnel temperatures and environmental conditions, there is a lack of prediction of the aging performance of gaskets and assessment of the impact of segment concrete corrosion performance on the leakage risks of gaskets. How to predict the leakage risks of gaskets at the joint parts to extend the service life of the tunnel and reduce economic losses is one of the current problems.

[0007] Moreover, the traditional processing technological process of shield tunnel segment gaskets is as follows: 1. Extrude the straight strip of the shield gasket; 2. Cut to a fixed length according to the segment size; 3. Join the corners of the straight strip into a frame. Currently, the corners of domestic shield tunnel segment gaskets are vulcanized and processed by injection corner joining method, and there is a solid section of 6 - 8 cm at the corners and the parts connected to the straight strip. The compression stresses at the corners and the straight strip are quite different. The compression stress of the solid part at the corners is 2 - 3 times that of the straight strip. Due to the large difference in compression stress, it is not only unfavorable for waterproofing but also affects the structural safety of the segment corners.

[0008] The traditional shield tunnel segment gasket is designed with a solid section of 6 - 8 cm in length at the corners. This design results in the cross-sectional area of the gasket corners being much larger than that of the segment grooves. During the segment assembly process, when the segment contacts and compresses the gasket, the too large cross-sectional area of the corner gasket makes this area unable to fully match the segment grooves, thus generating local stress concentration. This stress concentration will lead to uneven deformation of the corner gasket, further causing poor contact between the gasket and the segment, and then triggering damage to the segment corners. The related technical problem is that even if the cross-sectional area of the gasket is reduced, the phenomena of uneven stress distribution and uneven deformation still cannot be completely avoided because the design of the gasket and the fit with the segment grooves are still insufficient to ensure uniform compression during the assembly process.

[0009] In addition, in traditional designs, the opening ratio of the gasket is too large. When the gasket is compressed, this design is likely to result in insufficient internal extrusion stress. Insufficient extrusion stress will reduce the waterproof ability of the gasket, making it unable to effectively resist water pressure, thereby affecting the waterproof effect of the tunnel. Therefore, in the design of the gasket, it is necessary to consider the cross-sectional area, hole pattern design, and compression stress distribution to avoid the occurrence of the above problems. Summary of the Invention

[0010] The technical problem to be solved by the present invention is as follows: to promptly identify and discover the leakage problems caused by the corrosion of the segment itself and the aging of the gasket at the segment joints due to the long-term action of groundwater pressure.

[0011] To solve the above technical problem, the present invention provides the following technical solutions:

[0012] A method for predicting the leakage risk of an anchor-type gasket in a shield tunnel, comprising:

[0013] Determine the leakage risk index R of the gasket according to the acting stress F of groundwater pressure at the gasket joint, the aging coefficient P of the gasket, and the corrosion coefficient α of the segment concrete at the gasket joint part, where R = F·α·P;

[0014] Determine the ultimate waterproof ability Z of the gasket J ;

[0015] Compare the leakage risk index of the gasket with the ultimate waterproof ability. If R ≤ Z J , then give an early warning and take waterproof measures.

[0016] In an embodiment of the present invention, the ultimate waterproof ability of the gasket is determined by the following method:

[0017] Through a water seepage test, simulate the waterproof ability of the joint part of two gaskets under different opening amounts and misalignment amounts, and obtain the data of the waterproof ability, opening amount, and misalignment amount of the gasket;

[0018] Perform data fitting on the obtained data of the waterproof ability, opening amount, and misalignment amount of the gasket to obtain a waterproof ability relationship formula;

[0019] According to the characteristics of the water pressure action, divide the waterproof failure process of the gasket into multiple stages, and divide the stage of the water body wedging into the contact surface between two gaskets into the water wedging stage; and determine the waterproof ability of the gasket in the water wedging stage as the ultimate waterproof ability of the gasket;

[0020] According to the depth of the underground environment where the gasket is located and the gasket model, determine the opening amount and misalignment amount of the gasket in the water wedging stage by referring to data, and substitute them into the waterproof ability relationship formula to obtain the specific value of the ultimate waterproof ability of the gasket.

[0021] In an embodiment of the present invention, the acting stress F of the groundwater pressure at the gasket gap is obtained by the following method:

[0022] During the prefabrication process of the gasket, an optical fiber is longitudinally arranged along the arrangement direction of the gasket at the top of the water-facing side of the gasket, and the acting stress of the groundwater pressure at the gasket joint is obtained through the fiber optic sensor at the end of the optical fiber.

[0023] In an embodiment of the present invention, the aging coefficient P of the gasket is obtained by the following formula:

[0024]

[0025] In the formula, B, B0, B1, and B2 are undetermined coefficients, t is the aging time of the gasket, and T is the aging temperature;

[0026] Among them, the undetermined coefficients B, B0, B1, and B2 are obtained by the following method:

[0027] The gasket to be tested is tested under different temperature conditions, and the relevant data of the aging time t and the rubber gasket aging coefficient P under different temperature conditions T are respectively obtained for multiple linear regression fitting to obtain the undetermined coefficients B, B0, B1, and B2.

[0028] In an embodiment of the present invention, the corrosion coefficient α of the segment concrete at the gasket joint is obtained by the following method:

[0029] According to the climate zone of the construction site, the soil permeability of the concrete, and the conditions of dry-wet alternation and freeze-thaw alternation, it is divided into three types of environments;

[0030] Then, according to the environmental category and the evaluation standard of the corrosiveness of groundwater to building materials, the segment concrete corrosion coefficients under the conditions of slight corrosion, weak corrosion, medium corrosion, and strong corrosion in the three types of environments are determined.

[0031] In an embodiment of the present invention, the gasket includes a corner connection section 10 and a straight section 20; both ends of the corner connection section 10 are respectively connected to the straight section 20 and form a chamfer structure;

[0032] A deformation through-hole is provided in the corner connection section 10; and at least two rows of deformation through-holes are provided in the corner connection section 10, and the number of rows of deformation through-holes in the corner connection section 10 is less than the number of rows of deformation through-holes in the straight section 20.

[0033] In an embodiment of the present invention, the straight section 20 includes a straight section body 200 and an anchoring leg 21; the anchoring leg 21 is integrally formed with the straight section body 200, and the anchoring leg 21 is provided on both sides of the straight section body 200 and is located at the bottom of the straight section body 200.

[0034] In an embodiment of the present invention, the first row of corner deformation through-holes of the corner connection section 10 is located at the bottom of the corner connection section 10; moreover, the first row of corner deformation through-holes includes a first bottom buffer hole 11 and a second bottom buffer hole 12. The two bottom buffer holes have the same structure but different heights, forming a hierarchical buffer.

[0035] In an embodiment of the present invention, multiple rows of deformation through-holes are provided on the straight bar section body 200; the first row of straight bar deformation through-holes located at the bottom of the straight bar section body 200 has the same structure as the first row of corner deformation through-holes at the bottom of the corner connection section 10 and is in the same horizontal position.

[0036] In an embodiment of the present invention, the opening ratio k of the corner connection section 10 follows the following design rules:

[0037]

[0038] In the formula, A0 is the cross-sectional area of the outer shape of the corner connection section, H0 is the height of the outer shape of the corner connection section, A 1,i is the cross-sectional area of the i-th hole type on the outer shape of the corner connection section, H 1,i is the height of the i-th hole type on the corner connection section, C 孔型,i is the correction coefficient of the i-th hole type on the corner connection section, C 缓冲 is the hierarchical buffer correction coefficient of the bottom deformation through-holes on the corner connection section, and n is the number of the i-th hole type on the corner connection section;

[0039] Moreover, the opening ratio of the straight bar section body 200 reuses the design rules of the opening ratio of the corner connection section 10.

[0040] The present invention also provides a risk prediction system for leakage of a shield tunnel anchor type gasket, which applies the above-mentioned risk prediction method for leakage of a shield tunnel anchor type gasket, and includes:

[0041] A leakage risk module, which is used to determine the leakage risk index R of the gasket according to the acting stress F of the groundwater pressure at the gasket joint, the aging coefficient P of the gasket, and the corrosion coefficient α of the segment concrete at the gasket joint part, where R = F·α·P;

[0042] A waterproof module, which is used to determine the ultimate waterproof ability Z of the gasket J ;

[0043] An early warning module, which is used to compare the leakage risk index of the gasket with the ultimate waterproof ability. If R ≤ Z J , then give an early warning and take waterproof measures.

[0044] Compared with the prior art, the beneficial effects of the present invention are:

[0045] Based on the seepage test data, the present invention fits a quadratic polynomial of the waterproofing ability of two rectangular anchored gaskets under different opening amounts and offset amounts. According to the depth of the underground environment where the gasket is located and its model, the opening amount and offset amount required for the corresponding ultimate waterproofing ability can be directly determined. This method simplifies the process of obtaining the ultimate waterproofing ability. By measuring the ultimate waterproofing ability, leakage warnings can be issued in a timely manner, thereby predicting the leakage risk of the gasket in advance, extending the service life of the tunnel, and reducing the economic losses caused by tunnel repairs.

[0046] In the present invention, optical fibers are uniformly arranged along the gasket layout direction at the top of the water-facing side of the gasket. By the strain generated by the optical fibers under the action of groundwater pressure and combining its elastic modulus, the stress generated by the groundwater pressure on the joint of the gasket can be calculated. This method does not require calculating the groundwater pressure acting on the shield segment joint through the shield tunnel and the groundwater depth. In addition, through the real-time monitoring of the strain data, not only can we deeply understand the performance of the gasket under different pressure conditions, but also optimize the seal structure design, thereby improving its sealing effect and service life. Analyzing these data helps to further evaluate and accurately predict the reliability of the gasket during long-term use, discover potential water leakage risks in a timely manner, and formulate corresponding maintenance measures. This process effectively integrates optical fiber sensing technology with the structural analysis of the gasket, providing an important basis for ensuring the safety and efficiency of the sealing system.

[0047] The present invention optimizes and designs a shield tunnel anchored gasket with a closed bottom and two-sided anchoring feet, and the anchoring feet are fixed in the concrete as embedded components. Compared with traditional gaskets, the anchored gasket can effectively prevent water from leaking through the contact surface between the gasket and the segment groove, and at the same time avoid the dislocation and falling off of the gasket during the construction process, thereby significantly improving the waterproofing ability of the joint. In addition, the anchored gasket is prefabricated with the segment concrete section in the factory, which not only improves the construction efficiency, but also ensures the construction quality and reduces carbon emissions.

[0048] The present invention uses the time-temperature equivalence principle to effectively predict the aging characteristics of the gasket at the segment joint with the increase of service life under different temperature (10°C - 20°C) operating conditions of the tunnel. Through this method, the variation law between the leakage risk factors of the gasket and its aging performance within this temperature range can be revealed.

[0049] The present invention determines the corrosion coefficient of the segment concrete at the gasket joint for different environmental conditions, thereby effectively coping with the influence of various corrosion environment actions on the leakage risk of the joint part, and further improving the prediction standard of the leakage risk of the joint part.

[0050] The first bottom buffer hole and the second bottom buffer hole serve as bottom supporting holes, and their deformation processes are different. When the first bottom buffer hole is subjected to top pressure, it is deformed first, and then, after reaching a certain degree of deformation, the second bottom buffer hole is deformed immediately. Here, the present invention introduces the concept of graded buffering. If the same height is set, the bottom row holes will be squeezed and deformed at the same time, and the purpose of subsequent gradual deformation cannot be achieved, so as to gradually provide resistance to deformation in the later stage.

[0051] The opening rate of the gasket is an important parameter, which affects the compression stress distribution and sealing effect of the corner connection section 10 and the straight section 20. The opening rate of the present invention introduces a graded buffer correction coefficient and a hole type correction coefficient to ensure that the gasket can deform evenly when under pressure, avoid local stress concentration, and improve the waterproof ability and service life of the gasket. In addition, the design rule of introducing the opening rate also effectively reduces material waste, optimizes the force coordination between the corner area and other parts, and ensures the long-term stability of the gasket under complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The present invention is a flow chart of a method for predicting leakage risk of anchored sealing pads in a shield tunnel according to an embodiment of the present invention.

[0053] Figure 2 FIG. 4 is a schematic diagram of the operation of the optical fiber sensor according to an embodiment of the present invention.

[0054] Figure 3(a) , 3(b) It is a schematic diagram of residuals under different independent variables when fitting the aging coefficient data of an embodiment of the present invention.

[0055] Figure 4 It is a schematic diagram of waterproof capability data fitting according to an embodiment of the present invention.

[0056] Figure 5 Schematic diagram of a sealing gasket according to an embodiment of the present invention.

[0057] Figure 6 Schematic diagram of a corner connection section according to an embodiment of the present invention.

[0058] Figure 7 Schematic diagram of a straight segment according to an embodiment of the present invention.

[0059] Figure 8 It is a schematic diagram of the sealing gasket assembly according to an embodiment of the present invention.

[0060] Figure 9 Schematic diagram comparing the compression amount and compression force of the sealing gasket according to the embodiment of the present invention and the sealing gasket according to the prior art.

[0061] Figure 10Schematic diagram of the comparison between the joint opening amount and the seepage pressure of the gasket in the embodiment of the present invention and the gasket in the prior art.

[0062] Figure 11 Schematic diagram of the comparison between the joint opening amount and the maximum contact stress of the gasket in the embodiment of the present invention and the gasket in the prior art.

[0063] Figure 12 Simulation effect diagram of the gasket in the embodiment of the present invention.

[0064] Figure 13 Simulation effect diagram of the gasket in the prior art in the embodiment of the present invention.

[0065] Figure 14 Block diagram of a leakage risk prediction system for an anchor-type gasket in a shield tunnel in the embodiment of the present invention. Detailed implementation manners

[0066] To facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings of the specification.

[0067] The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0068] Embodiment 1

[0069] Please refer to Figure 1 As shown, the present invention provides a method for predicting the leakage risk of an anchor-type gasket in a shield tunnel, including:

[0070] S10. Determine the leakage risk index R of the gasket according to the acting stress F of the groundwater pressure at the joint of the gasket, the aging coefficient P of the gasket, and the corrosion coefficient α of the segment concrete at the joint of the gasket, where R = F·α·P.

[0071] See Figure 2 As shown, in an embodiment of the present invention, the acting stress F of the groundwater pressure at the gap of the gasket is obtained by the following method:

[0072] At the top of the water-facing side of the gasket, along the layout direction of the gasket, optical fibers are arranged throughout the length, that is, arranged along the length direction. These optical fibers will be combined with the gasket by means such as pasting and embedding during the prefabrication process of the gasket to ensure its effective functioning. In this embodiment, the embedded type is adopted. In practical applications, when the groundwater pressure acts on the gasket, the optical fibers will generate strain due to the pressure change. Through high-precision optical fiber sensors, these strains can be monitored in real time to effectively respond to the stress changes caused by groundwater changes at the gasket joint, and obtain the stress F caused by the groundwater pressure on the gasket joint. This process not only helps to understand the performance of the gasket under different pressure conditions, but also can optimize the seal structure design, thereby improving its sealing effect and service life. In addition, by analyzing these data, the reliability of the gasket during long-term use can be further evaluated and predicted, potential water leakage risks can be detected in a timely manner, and corresponding maintenance measures can be formulated. The effective integration of optical fiber sensing technology and the structural analysis of the gasket provides an important basis for ensuring the safety and efficiency of the seal system.

[0073] In an embodiment of the present invention, the "P-T-t" ternary aging time-varying model is adopted, and the aging coefficient P of the gasket is fitted through data. Then, using the time-temperature equivalence principle, the aging characteristics of the gasket at the segment joint with the increase of service life are predicted under the operating conditions of different temperatures (10°C - 20°C) in the tunnel.

[0074] Both the "P-T-t" ternary model and the Arrhenius plot extrapolation model are based on a premise that the rubber aging model mechanism is consistent with the artificial accelerated rubber aging test mechanism, and the accelerated aging chemical reactions of rubber materials all obey the Arrhenius plot equation. For the "P-T-t" ternary aging time-varying model, the aging coefficient P of the gasket, the aging temperature T, and the gasket aging time t can be expressed by the following formula:

[0075]

[0076] In the formula, P is the aging coefficient of the gasket, B, B0, B1, and B2 are undetermined coefficients, t is the gasket aging time, and T is the aging temperature.

[0077] By transforming the above formula, we can get:

[0078]

[0079] According to the "Rapid Determination Method for the Storage Period of Static Sealing Rubber Parts", an artificial accelerated aging test was conducted on the composite gasket under study. The premise of the test is that the principle of artificial accelerated aging is consistent with the principle of natural aging. Therefore, the gasket manufacturer conducted tests on the gaskets to be tested at temperatures of 60°C (333.15K), 75°C (348.15K), and 90°C (363.15K) respectively, and obtained the relevant data of the aging time t and the rubber gasket aging coefficient P under different temperature T conditions, as shown in Table 1.

[0080] Table 1 Test data of gasket aging coefficient

[0081]

[0082] After deforming the test data according to the "P-T-t" ternary aging time-varying model according to the following formula, multiple linear regression fitting was performed on the data.

[0083] Y0 = B0 + B1X1 + B2X2;

[0084] Among them, Y0 = log(-log(P / B)); X1 = logt; X2 = 1 / T; B0, B1, and B2 are obtained by linear regression fitting of the above test data; B is obtained by successive approximation of the fitting data, and the specific parameters are shown in Table 2.

[0085] Table 2 Specific parameters of the undetermined coefficients in the aging coefficient

[0086]

[0087] Such as Figure 3(a) 、 3(b) As shown, after analysis, the sum of squared residuals under different independent variables is 0.080, and the goodness of fit R 2 = 0.977, and the model fitting effect is good. From the data, the calculation analytical formula of the gasket aging coefficient P, aging time t, and aging temperature T is:

[0088]

[0089] Using the time-temperature equivalence principle, the above formula can predict the aging characteristics of the gaskets at the segment joints with the increase of service life under different temperature (10°C - 20°C) operating conditions of the tunnel.

[0090] In an embodiment of the present invention, the corrosion coefficient α of the segment concrete at the gasket joint is determined. According to the destructive effects caused by various chemical corrosions, the content of ions is summarized as an evaluation index of crystalline corrosiveness; the erosive CO2 ions and pH value are summarized as an evaluation index of decomposition corrosiveness; and Mg 2+ 、Cl -The content of ions is used as an evaluation index for crystallization decomposition type corrosion. At the same time, when evaluating the corrosion of groundwater to building structural materials, the environmental category to which the building site belongs must be combined. The building site is divided into three types of environments according to the climate zone, soil layer permeability, wet-dry alternation and freeze-thaw alternation, as shown in Table 3.

[0091] Table 3 Site environmental categories for concrete corrosion Site environmental categories for concrete corrosion

[0092]

[0093]

[0094] According to the provisions of the "Code for Geotechnical Engineering Investigation", the evaluation standards for the corrosion of groundwater to building materials are shown in Table 4.

[0095] Table 4 Evaluation standards for the corrosion of groundwater to building materials Evaluation standards for crystallization type corrosion

[0096]

[0097] Evaluation standards for decomposition type corrosion

[0098]

[0099] Evaluation standards for crystallization decomposition composite type corrosion

[0100]

[0101] According to the site environmental categories for concrete corrosion and the evaluation standards for the corrosion of groundwater to building materials, the values of the segment concrete corrosion coefficient α under the conditions of slight corrosion, weak corrosion, medium corrosion and strong corrosion in environmental categories I-III are determined as shown in Table 5.

[0102] Table 5 Values of the segment concrete corrosion coefficient α

[0103]

[0104]

[0105] S20, determine the ultimate waterproofing ability Z of the gasket J 。

[0106] In an embodiment of the present invention, the ultimate waterproofing ability of the gasket is determined in the following manner:

[0107] S21, through a water seepage test, simulate the waterproofing ability of the joint part of two gaskets under different opening amounts and misalignment amounts, and obtain the data of the waterproofing ability, opening amount and misalignment amount of the gasket. For details, please refer to Table 6.

[0108] Data on the waterproofing ability, opening amount, and offset amount of the gasket

[0109]

[0110] S22. For the obtained data on the waterproofing ability, opening amount, and offset amount of the gasket, perform data fitting to obtain the waterproofing ability relationship formula.

[0111] In this embodiment, establish a quadratic polynomial, and use data processing software to fit the formula in combination with the test results: Z = Z0 + aX + bY + cX 2 + dY 2 + fXY, where Z is the waterproofing ability of the gasket, X is the opening amount, and Y is the offset amount. X ranges from 0 to 10 mm, and Y takes 0, 4, 8, 12, 16 mm. Z0, a, b, c, d, and f are the coefficients to be fitted in the waterproofing ability relationship formula.

[0112] The fitted formula is: Z = -1.37963X - 0.1258Y + 0.04961X 2 - 0.00209Y 2 + 0.01172XY + 9.04933, and the goodness of fit R 2 = 0.994, indicating that the model fitting effect is good, as shown in Figure 4 shown.

[0113] S23. According to the characteristics of water pressure action, divide the waterproof failure process of the gasket into multiple stages, and divide the stage of water body wedging into the contact surface between two gaskets into the water wedging stage; and determine the waterproofing ability of the gasket in the water wedging stage as the ultimate waterproofing ability of the gasket.

[0114] In this embodiment, according to the characteristics of water pressure action, divide the failure process of the anchored gasket waterproofing system into four stages, namely the segment compression stage, water compression stage, water wedging stage, and water breakthrough stage. When reaching the water wedging stage, the waterproofing ability of the gasket reaches the limit state, and the waterproofing ability at this time is Z J .

[0115] In this embodiment, in the segment compression stage test, it is the initial extrusion stage of the gasket. In actual engineering, it is the compression deformation stage of the gasket under the jacking force during the assembly and compression of shield segments.

[0116] In the water compression stage test, it is the process of mutual extrusion between the upper and lower specimens. In actual engineering, after the assembly of shield segments is completed, water begins to act on the front of the gasket. Under the action of water pressure, water wedges into the contact surface between the gasket and the segment, causing the gasket to shift and deform towards the back.

[0117] The water wedging stage is when water wedges into the contact surface between the gaskets. The gaskets are laterally extruded by the water body along a specific dimension, and the water body perpendicular to the wedging direction further extrudes the holes of the gaskets. The blocking force of the lining segment is further enhanced, thus significantly increasing the contact stress between the gaskets and the segments.

[0118] The water breakthrough stage is the critical contact state where water breaks through the gaskets, and separation occurs between the gaskets, rendering the waterproofing ability of the gaskets ineffective.

[0119] S24. According to the depth of the underground environment where the gasket is located and the gasket performance, determine the opening amount and misalignment amount of the gasket in the water wedging stage by referring to data, and substitute them into the waterproofing ability relationship formula to obtain the specific value of the ultimate waterproofing ability of the gasket.

[0120] In this embodiment, according to the depth of the underground environment where the gasket is located and the gasket model in the actual project, determine how much the opening amount X and misalignment amount Y of the gasket should be to meet the basic waterproof design requirements. Substitute the opening amount X and misalignment amount Y into the fitted quadratic polynomial to obtain the ultimate waterproofing ability Z of the gasket. J In this example, when the opening amount is 7 mm and the misalignment amount is 12 mm, it meets the requirements. Substitute these values into the fitting formula to find the ultimate waterproofing ability Z of the gasket at this time. J It is 0.87.

[0121] In this embodiment, during the design of the gasket, a water seepage test is always conducted to obtain the relationship data between the waterproofing ability of the gasket and the opening amount and misalignment amount.

[0122] S30. Compare the gasket leakage risk index with the ultimate waterproofing ability. If R ≤ Z J , then give an early warning and take waterproofing measures.

[0123] In this embodiment, for predicting the leakage risk of the anchored gasket in the shield tunnel, first determine the key parameters in the leakage assessment of the anchored gasket in the shield tunnel: F, P, α, and Z. J . Calculate the gasket leakage risk index R = F·α·P according to the above parameters, and compare the calculation result with the ultimate waterproofing ability Z of the gasket J for predicting the leakage risk of the anchored gasket in the shield tunnel. If R ≤ Z J , it indicates that there is a leakage risk in the current state. At this time, an early warning should be issued in a timely manner, and further risk assessment and analysis should be carried out to find the possible leakage sources and take corresponding waterproofing measures. After implementing the waterproofing measures, real-time monitoring should continue to ensure the effectiveness of these measures, and record all monitoring data and changes in the leakage situation for reference and guidance in subsequent construction.

[0124] Example 2

[0125] Please refer to Figure 5 and Figure 6 As shown, this embodiment provides an anchor-type gasket, which is applied in Embodiment 1. Specifically, the gasket includes a corner connection section 10 and a straight section 20. Both ends of the corner connection section 10 are respectively connected to the straight section 20, and a chamfer structure is formed. A deformation through-hole is provided in the corner connection section 10, and at least two rows of deformation through-holes are provided in the corner connection section 10, and the number of rows of deformation through-holes in the corner connection section 10 is less than the number of rows of deformation through-holes in the straight section 20.

[0126] In this embodiment, in the traditional design, the corner connection section 10 is in a closed state without opening holes. Although this design can provide a certain deformation ability, in actual applications, it cannot effectively solve the matching problem between the corner connection section 10 and the straight section 20. Especially when subjected to extrusion force, the corner connection section 10 is prone to stress concentration or uneven deformation, which will affect the overall waterproof performance of the gasket. By opening holes in the corner connection section 10, it is ensured that the gasket does not have stress concentration at the corner, avoiding corner damage or leakage.

[0127] In this embodiment, the number of rows of deformation through-holes in the corner connection section 10 is less than the number of rows of deformation through-holes in the straight section 20, resulting in differences in stress distribution and deformation characteristics between the corner connection section 10 and the straight section 20 at the corner part of the gasket.

[0128] In this embodiment, a first row of corner deformation through-holes and a second row of corner deformation through-holes are provided on the corner connection section 10. The hole shape of the second row of corner deformation through-holes is not limited in this embodiment.

[0129] The differential design of the stress distribution and deformation characteristics between the corner connection section 10 and the straight section 20 can effectively solve the following technical problems:

[0130] 1. Uniform stress distribution:

[0131] By reducing the number of rows of deformation through-holes in the corner connection section 10, the gasket in the corner connection section 10 can better adapt to bending deformation under the action of extrusion force, enabling the corner connection section 10 to evenly distribute the compressive stress and avoiding local stress concentration caused by uneven deformation. In contrast, due to stronger compression, the straight section 20 requires more rows of deformation through-holes to provide sufficient deformation ability.

[0132] 2. Improve the matching between the corner connection section 10 and the straight section 20:

[0133] In this embodiment, the corner connecting segment 10 is provided with two rows of deformation through holes, and the straight segment 20 is provided with three rows of deformation through holes. Among them, the design of different numbers of rows of holes can make the corner connecting segment 10 and the straight segment 20 work better in coordination during the overall compression process. The corner connecting segment 10 has fewer rows of holes, which helps the area to be more flexible during compression to adapt to the special deformation requirements of the corner, while the straight segment 20 needs to withstand greater compression force, so the three rows of deformation through holes design provides stronger support. In this way, when the sealing gasket is under pressure as a whole, the corner connecting segment 10 and the straight segment 20 can deform together under the action of the same force, ensuring the overall structural stability of the sealing gasket and avoiding the reduction of the sealing effect due to uneven deformation.

[0134] 3. Reduce local deformation failure:

[0135] By reducing the number of holes in the corner connecting section 10, excessive deformation caused by too many holes is avoided, especially in a high-pressure environment, which helps the sealing gasket maintain stability and waterproof performance for a longer period of time. At the same time, the design of reducing the number of holes enables the corner connecting section 10 to effectively cope with compression when the sealing gasket is subjected to extrusion force, avoiding the problem of sealing failure caused by excessive deformation.

[0136] In one embodiment of the present invention, the first row of corner deformation through holes of the corner connecting section 10 is located at the bottom of the corner connecting section 10. Also, the first row of corner deformation through holes includes a first bottom buffer hole 11 and a second bottom buffer hole 12, the two bottom buffer holes have the same structure and different heights, forming a graded buffer. Specifically, the height difference between the first bottom buffer hole 11 and the second bottom buffer hole 12 is 1 to 2 mm, and the specific height difference between the first bottom buffer hole 11 and the second bottom buffer hole 12 is obtained through multiple simulations and actual test verifications. If the height difference is too large, it is not conducive to compression, and if it is too small, the deformation is too large.

[0137] In this embodiment, the first bottom buffer hole 11 is located at the end of the first row of corner deformation through holes, and the plurality of second bottom buffer holes 12 are located in the middle of the first row of corner deformation through holes. Specifically, the first bottom buffer hole 11 and the second bottom buffer hole 12 are oblique arched holes.

[0138] In this embodiment, the first bottom buffer hole 11 and the second bottom buffer hole 12 serve as bottom supporting holes, and their deformation processes are different. When the first bottom buffer hole 11 is subjected to top pressure, it is deformed first, and then, after reaching a certain degree of deformation, the second bottom buffer hole 12 is deformed immediately. Here, the present invention introduces the concept of graded buffering. If the same height is set, the bottom row of holes will be squeezed and deformed at the same time, and the purpose of subsequent gradual deformation cannot be achieved, so as to gradually provide resistance to deformation in the later stage.

[0139] In this embodiment, both ends of the corner connection section 10 are respectively connected to the straight section 20 to form a chamfer structure, which makes the compression at the corner more uniform and avoids stress concentration. Among them, the cutting surface angles at both ends of the corner connection section 10 are between 30° and 80°, ensuring the compression ability of the gasket and optimizing according to the structural strength requirements of the gasket to ensure that the gasket does not have excessive influence during compression. Specifically, the chamfer formed by the connection of the corner connection section 10 and the straight section 20 is, for example, an arc structure, a single-fold shape, or a double-fold shape.

[0140] In an embodiment of the present invention, the porosity of the gasket is an important parameter, which affects the compression stress distribution and sealing effect of the corner connection section 10 and the straight section 20. Among them, the design rule of the porosity k on the corner connection section 10 is as follows:

[0141]

[0142] In the formula, A0 is the cross-sectional area of the outer shape of the corner connection section, H0 is the height of the outer shape of the corner connection section, A 1,i is the cross-sectional area of the i-th hole type on the outer shape of the corner connection section, H 1,i is the height of the i-th hole type on the corner connection section, C 孔型,i is the correction coefficient of the i-th hole type on the corner connection section, C 缓冲 is the grading buffer correction coefficient of the bottom deformation through hole on the corner connection section, and n is the number of the i-th hole type on the corner connection section.

[0143] In this embodiment, the correction coefficient of the i-th hole type is obtained in the following way: determine the reference hole type, obtain the ratio of the area to the perimeter of the reference hole type, and record it as the reference coefficient, obtain the ratio of the area to the perimeter of the i-th hole type, and record it as the hole type coefficient, and take the ratio of the hole type coefficient of the i-th hole type to the reference coefficient as the correction coefficient of the i-th hole type.

[0144] Specifically, for example: select the reference hole type - circular.

[0145] 1) The reason for using the circular hole as the reference is that its deformation performance is the most stable, the ratio of the perimeter to the area is fixed, and the pressure distribution is uniform when closed.

[0146] Assume that the radius of the circular hole takes a value of 5 mm;

[0147] Area A 圆形 = πr 2 = 78.54 mm 2 ; Perimeter P 0圆形 = 2πr = 31.42 mm;

[0148] The correction coefficient C of the circular hole 圆形= 1, which serves as a reference for subsequent calculations of other pass shapes.

[0149] 2) Define the geometric parameters of other pass shapes

[0150] Oval pass:

[0151] Assume the major axis a0 of the oval pass is 6 mm, the minor axis b0 is 4 mm, and the area A 椭圆 = πa0b0 = 76.40 mm 2 .

[0152]

[0153] (A / P0) 椭圆 = 75.40 / 25.42 = 2.96;

[0154] The pass shape coefficient of the oval pass, C 椭圆 = 2.96 / 2.5 = 1.18;

[0155] Four-corner arc pass:

[0156] Assume the four-corner arc pass is composed of a rectangle 5 mm * 3 mm and four semi-circles:

[0157] Area A 四角弧形 = Rectangle area + 4 * 1 / 4 * Circle area = (5 * 3 *) + 4 * 1 / 4πr 2 ;

[0158] Among them, the radius of the circle is taken as 1.5 mm, then the area A 四角弧形 = 22.07 mm 2 ;

[0159] Perimeter P 0四角弧形 = 2(5 + 3) - 4r + 4 * / 4 * Circle perimeter = 19.42 mm;

[0160] Then, (A / P0) 四角弧形 = 22.07 / 19.42 = 1.14;

[0161] The pass shape coefficient C of the four-corner arc pass 四角弧形 = 1.14 / 2.5 = 0.46;

[0162] And so on for other pass shapes.

[0163] The process of obtaining the grading buffer correction coefficient is as follows:

[0164]

[0165] In the formula, β is the grading buffer efficiency coefficient, which reflects the influence of the geometric shape and position of the holes on the buffering effect. The accuracy of the data is verified by finite element simulation to ensure that the β value has a scientific basis. h0 is the height difference of the deformed through holes at the upper bottom of the corner connection section, which can be understood as the height difference between the first bottom buffer hole 11 and the second bottom buffer hole 12.

[0166]

[0167] In the formula, ΔF 缓冲 is the total reduction in the compression force of the corner connection section when the grading buffer is introduced, and ΔF 总 is the total compression force of the corner connection section when the grading buffer is introduced, and F 基准 is the total compression force of all the holes on the corner connection section deforming synchronously under the non-grading buffer design, and F 缓冲 is the total reduction in the compression force of the corner connection section when the grading buffer design is introduced.

[0168] The reduction in the compression force F 缓冲 Buffer: When the height difference h0 is introduced in the grading buffer design, the compression force distribution of the corner connection section will change: the first bottom buffer hole 11 deforms first to absorb part of the pressure, and the second bottom buffer hole 12 deforms later to relieve the total compression force.

[0169] The total reduction in the compression force ΔF 缓冲 , in the case of the non-grading buffer design, that is, h0 = 0, all the holes deform synchronously, and the total compression force is F 基准 .

[0170] In this embodiment, through the experimental and simulation results, the value range of β is determined to be: 1.3 ≤ β ≤ 1.6.

[0171] The grading buffer correction coefficient C 缓冲 Range: 1.052 ≤ C 缓冲 ≤ 1.128

[0172] Through the above complete design process, it can be ensured that the corner connector has excellent performance in actual applications and meets the design goals. There is no doubt that the opening rate on the straight section 20 follows the design rule of the opening rate on the corner connection section 10.

[0173] Please refer to Figures 5 to 8As shown, the straight bar section 20 includes a straight bar section body 200 and anchoring legs 21. Specifically, both ends of the corner connection section 10 are respectively connected to the straight bar section body 200 and form a chamfer structure. The anchoring legs 21 are integrally formed with the straight bar section body 200, and the anchoring legs 21 are arranged on both sides of the straight bar section body 200 and are located at the bottom of the straight bar section body 200. When in use, the anchoring legs 21 are embedded in the concrete mortar during the pouring of the concrete segment, and after the concrete mortar solidifies, the gasket is fixed in the concrete segment 300 and forms an integral body with it, which can overcome the defects of poor controllability of pasting of traditional rubber elastic gaskets and easy displacement or falling off during construction extrusion. See Figure 8 As shown. Under the action of the jack thrust and the bolt tightening force, the gasket between the joints of the segment 300 is compressed and deformed to form a closely attached contact surface, which can effectively improve the waterproof quality of the longitudinal joints and circumferential joints of the segment, and at the same time avoid the problem that the gasket detaches from the segment 300 when the deformation of the gasket is excessive.

[0174] In an embodiment of the present invention, multiple rows of deformation through holes are provided on the straight bar section body 200. Specifically, the straight bar section body 200 includes a first row of straight bar deformation through holes, a second row of straight bar deformation through holes, and a third row of straight bar deformation through holes. The first row of straight bar deformation through holes at the bottom of the straight bar section body 200 has the same structure as the first row of corner deformation through holes at the bottom of the corner connection section 10 and is at the same horizontal position. That is, it can be understood that a third bottom buffer hole 211 and a fourth bottom buffer hole 212 are provided on the first row of straight bar deformation through holes, and both are inclined arch holes. The third bottom buffer hole 211 is located at the end of the first row of straight bar deformation through holes, and multiple fourth bottom buffer holes 212 are located in the middle of the first row of straight bar deformation through holes. The first bottom buffer hole 11 corresponds to the third bottom buffer hole 211, and the second bottom buffer hole 12 corresponds to the fourth bottom buffer hole 212. And, the height difference h between the third bottom buffer hole 211 and the fourth bottom buffer hole 212 is: 1 mm ≤ h ≤ 2 mm. And the first bottom buffer hole 11, the second bottom buffer hole 12, the third bottom buffer hole 211, and the fourth bottom buffer hole 212 are at the same horizontal position, so that the horizontal heights of the first row of corner deformation through holes and the first row of straight bar deformation through holes must be kept consistent to ensure that when the gasket is subjected to extrusion force, the forces on each part are balanced. If there is a deviation in the horizontal height, the following problems may occur:

[0175] Uneven force affects the sealing performance: If the bottom row heights of the straight bar section 20 and the corner connection section 10 are inconsistent, when assembling the segments, the compression degrees of the gasket at different parts are different, which may cause some areas to be over-compressed, the material stress of the gasket to be concentrated, and local damage to easily occur. While in other areas, the compression is insufficient, resulting in a decrease in the contact surface pressure, affecting the overall sealing effect and increasing the risk of water seepage.

[0176] Local stress concentration exacerbates material aging: Due to uneven stress, local areas may be in a high-stress state for a long time, accelerating the aging and fatigue of rubber, shortening the service life of the gasket, and thus reducing the long-term waterproof performance of the shield tunnel.

[0177] Installation errors during the assembly process: If the bottom row heights of the straight section 20 and the corner connection section 10 are different, during construction, there may be significant errors in the installation of the gasket, making it difficult to ensure the stable positioning of the gasket in the segment groove, and even misalignment may occur during assembly, further affecting the sealing effect.

[0178] It should be noted that in the present invention, the top of the gasket, the top of the corner connection section 10, and the top of the straight section 20 are all in the same direction, which is the non-connected side of the segment. Without a doubt, the bottom of the gasket, the bottom of the corner connection section 10, and the bottom of the straight section 20 are all in the same direction and are connected to the segment.

[0179] In an embodiment of the present invention, a coaxial polygonal top-bottom arc hole 221 and a four-corner arc hole 222 are provided on the second row of straight strip deformation through holes. The polygonal top-bottom arc hole 221 is located at the end of the second row of straight strip deformation through holes, and the four-corner arc hole 222 is located in the middle of the second row of straight strip deformation through holes.

[0180] In an embodiment of the present invention, a coaxial semi-star hole 231 and an arc elliptical hole 232 are provided on the third row of straight strip deformation through holes. The semi-star hole 231 is located at the end of the third row of straight strip deformation through holes, and the arc elliptical hole 232 is located in the middle of the third row of straight strip deformation through holes.

[0181] In an embodiment of the present invention, the polygonal top-bottom arc hole 221 is a hexagon in this embodiment. The polygonal top-bottom arc hole 221 and the four-corner arc hole 222, as the second row of straight strip deformation through holes, can generate a greater supporting force to resist compression deformation than the arc elliptical hole 232, causing a large contact stress to be generated while the arc elliptical hole 232 is compressed to prevent water seepage. Currently, in most gaskets, the position of the polygonal top-bottom arc hole 221 is set as a circular hole to achieve the purpose of deformation. However, in the present invention, the polygonal top-bottom arc hole 221 is designed as a six-sided top-bottom arc, which can slow down subsequent excessive deformation while achieving deformation.

[0182] In this embodiment, the principle that the polygonal top-bottom arc hole 221 can slow down subsequent excessive deformation while achieving deformation is as follows:

[0183] 1. Deformation and mitigation of excessive deformation: The hexagonal top and bottom arc design can provide a more uniform stress distribution under pressure compared to traditional circular holes. Circular holes concentrate stress in the central area of the hole under pressure, which may lead to excessive deformation and affect the long-term stability of the gasket. By designing the polygonal top and bottom arc hole 221 as a hexagonal top and bottom arc, the shape of the hole can disperse stress more during compression, making the deformation process smoother, thus mitigating subsequent excessive deformation and preventing premature fatigue or failure of the material.

[0184] 2. Optimization of geometric shape: The hexagonal top and bottom arc design can achieve better deformation control, unlike circular holes that are prone to stress concentration. This geometric structure design can control the deformation amount of the hole during compression, enabling it to meet the design requirements while avoiding excessive or uneven deformation, and increasing the service life of the gasket.

[0185] 3. Advantages compared to circular holes: Compared with traditional circular holes, the hexagonal top and bottom arc design has certain geometric advantages. The angles and boundaries of the hexagonal design can make the stress more uniform and effectively inhibit stress concentration, thereby preventing the gasket from deforming or being damaged prematurely to a certain extent.

[0186] 4. Support force and resistance to compressive deformation: The synergistic effect of the hexagonal top and bottom arc design of the polygonal top and bottom arc hole 221 and the four-corner arc hole 222 enables this part of the hole structure to provide greater support force during compression and effectively resist compressive deformation. In this way, when the upper arc-shaped elliptical hole 232 is under pressure, the polygonal top and bottom arc hole 221 will generate appropriate contact stress and play an auxiliary compression role, thereby further enhancing the waterproof effect and preventing water seepage problems caused by water pressure.

[0187] In an embodiment of the present invention, the radian of the top and bottom two corners in the arc-shaped elliptical hole 232 is greater than the radian of the two corners in its own axis direction, and the radian of the top and bottom two corners in the four-corner arc hole 222 is greater than the radian of the two corners in its own axis direction. The arc-shaped elliptical hole 232 is a modified hole of the four-corner arc hole 222, which increases the radian of the top and bottom corners. This makes it easier for the arc-shaped elliptical hole 232 to be completely closed when subjected to the pressure from the gasket on the other side of the top of the adjacent segment, and the contact stress between the gaskets on the two segments will not be too small.

[0188] In this embodiment, the distance difference H between the third row of straight deformed through holes and the top of the straight segment body 200 is designed to take a value range of: 1≤H≤2mm. In this embodiment, the distance difference H is repeatedly determined through simulation. If the value is too large, it is not conducive to the effective compression of the hole position, which may cause insufficient deformation of the sealing gasket and affect the waterproof effect. If the value is too small, it may cause the hole shape to deform too much, affecting the compression adaptability of the sealing gasket, and then may affect the sealing performance and the overall structure of the sealing gasket. Therefore, after repeated verification and optimization, this precise range is obtained, and the optimal balance between the waterproof effect and the sealing performance is ensured through precise parameter optimization and simulation verification. Compared with the traditional hole design, the third row of straight deformed through holes can better distribute stress under the action of water pressure, prevent the corners of the sealing gasket from tilting or failing, and ensure the durability and stability of the waterproof performance. The breakthrough and optimization of these technical details show the technical difficulty of the design, especially in terms of the compression adaptability of the sealing gasket and the deformation ability under water pressure, which is not a common standard practice in the industry.

[0189] In one embodiment of the present invention, the semi-star-shaped holes 231 are mainly used to form a group of easily deformable through holes with the four-corner arc-shaped holes 222, so that the through holes in this part are completely closed, and then the deformation of the sealing gasket body caused by the lateral force of the water pressure is much smaller than that of the circular or triangular through holes that are not completely compressed and fitted. At the same time, it can prevent the corners of the waterproof sealing gasket from warping up under the action of water pressure, causing water seepage in the contact area between the waterproof sealing gasket and the pipe segment groove.

[0190] In one embodiment of the present invention, the top corners of the four-corner arc-shaped holes 222 are located in the third row of straight strip deformation through holes, at the opposite position of the axial direction angles of two adjacent deformation through holes. The bottom corners of the four-corner arc-shaped holes 222 are located in the first row of straight strip deformation through holes, between two adjacent deformation through holes, so that the four-corner arc-shaped holes 222 are staggered with the third row of straight strip deformation through holes and the first row of straight strip deformation through holes.

[0191] In this embodiment, the quadrangular arc-shaped hole 222 complements the semi-star-shaped hole 231 and the arc-shaped elliptical hole 232 .

[0192] The functions of the semi-star-shaped hole 231 and the four-corner arc-shaped hole 222 are complementary: the relative layout of these two hole shapes, through the change of relative position, can effectively promote the deformation of the through holes in this area, and promote the sealing gasket to achieve more uniform compression under the action of water pressure. In particular, the cooperation of the semi-star-shaped hole 231 and the four-corner arc-shaped hole 222 can minimize the risk of the corners of the waterproof sealing gasket warping when water pressure acts. Under the action of water pressure, the design of the semi-star and four-corner arc-shaped holes can help the corners of the sealing gasket maintain a good fit, avoid the warping problem caused by uneven compression, and thus prevent waterproof failure. Through this design, the sealing gasket can effectively avoid the warping of the corners caused by water pressure and ensure the integrity of the waterproof area.

[0193] The four-corner arc-shaped holes 222 and the arc-shaped elliptical holes 232 complement each other:

[0194] 1. Function of the four-corner arc hole 222: The four-corner arc hole 222 is mainly used to cooperate with the design of the arc-shaped elliptical hole 232 to form a set of easily deformable through-hole structures. Together with the semi-star-shaped hole 231 and the arc-shaped elliptical hole 232, it constitutes the deformation structure of the sealing gasket. Through the cooperation of the four-corner arc hole 222 and other holes, it helps the sealing gasket to close more evenly under the action of water pressure, ensuring that the deformation of the entire sealing gasket is within a certain range to improve the sealing performance. Especially under the action of the water pressure side, the four-corner arc hole 222 can effectively disperse the pressure and avoid excessive local stress.

[0195] 2. Function of the arc-shaped elliptical hole 232: The main purpose of the arc-shaped elliptical hole 232 is to cooperate with the sealing pressure on the opposite side segment, so that it can achieve more uniform deformation when subjected to force, prevent incomplete closure, and ensure that the corners do not lift up under the action of water pressure. Compared with the four-corner arc-shaped holes 222, the shape of the arc-shaped elliptical hole 232 is more suitable for forming a suitable deformation closure under specific forces such as water pressure side force, and better meet the overall deformation requirements of the sealing gasket.

[0196] 3. The cooperation of the four-corner arc holes 222 and the arc-shaped elliptical holes 232 prevents the corners from lifting under water pressure: The cooperation of the four-corner arc holes 222 and the arc-shaped elliptical holes 232 can effectively prevent the corners of the sealing gasket from lifting under water pressure. In particular, by designing the cooperation of the four-corner arc holes 222 and the arc-shaped elliptical holes 232, it is ensured that the sealing gasket will not have local stress concentration under water pressure, avoiding the lifting phenomenon caused by uneven pressure, thereby improving the overall sealing effect and preventing water seepage.

[0197] 4. The arc-shaped elliptical hole 232 cannot replace the square arc-shaped hole 222: The two types of holes play different functions at different positions of the sealing gasket, and have obvious differences in design, but they are not mutually exclusive. Under the action of water pressure, the square arc-shaped hole 222 and the arc-shaped elliptical hole 232 form a good complementary relationship, and through a common deformation mechanism, they effectively prevent the corners of the sealing gasket from warping or incomplete deformation. Therefore, the square arc-shaped hole 222 cannot be simply replaced by the arc-shaped elliptical hole 232, because there are differences in their shapes and functions. The arc-shaped elliptical hole 232 is more focused on deformation and closure under the action of water pressure, while the square arc-shaped hole 222 shares stress in synergy and promotes more uniform compression and closure.

[0198] See also Figures 9 to 13As shown in the figure, in an embodiment of the present invention, during the design process, the gasket designed by the present invention is compared with the gasket in the utility model with the patent publication number CN218150918U in the prior art by using finite element simulation to obtain the closing compression force, seepage pressure, and maximum contact stress.

[0199] When the gasket is compressed to different positions during the finite element numerical simulation analysis, the closing compression force, seepage pressure, and maximum contact stress of the gasket are as follows Figures 9 to 11 As shown in the figure, the best gasket 1 is obtained by screening the calculation roadmap, where gasket 1 is the gasket of the present invention and gasket 2 is the gasket in the utility model patent with the patent publication number CN218150918U in the prior art.

[0200] From Figure 9 it can be seen that when the compression amount reaches 18 mm, the compression force required for gasket 2 reaches 195 kN / m, exceeding the shield jack assembly force of 125 kN / m, while the compression force required for gasket 1 when the compression amount reaches 18 mm is less than 125 kN / m. From Figure 10 it can be seen that when the joint opening is 5 mm, the seepage pressure of gasket 2 is 1.4 MPa, which is greater than the waterproof requirement of 1.3 MPa, while the seepage pressure of gasket 1 is 2.5 MPa, which is far greater than the waterproof requirement of 1.3 MPa. As Figure 5 shown, the gasket contact stress - joint opening curve is obtained. From Figure 11 it can be known that when the joint opening of the segment joint gasket is 0, the maximum contact stress of gasket 1 is 3.6 MPa, which is significantly greater than the maximum contact stress of gasket 2, which is 2.5 MPa. The simulation effect is as Figure 12 and Figure 13 shown.

[0201] From the above comparison, it can be seen that the compression force required for gasket 1 is smaller at the same compression amount, the seepage pressure of gasket 1 is better at the same joint opening, and the maximum contact stress of gasket 1 is greater when the joint opening of the joint gasket is 0. Therefore, the waterproof ability of gasket 1 is better than that of gasket 2. Thus, the waterproof gasket in this embodiment meets the engineering requirements and has a better effect among the same type of anchored gaskets.

[0202] Embodiment 3

[0203] Please refer to Figure 14 As described, the present invention also provides a leakage risk prediction system for the anchored gasket of a shield tunnel, which applies the leakage risk prediction method for the anchored gasket of a shield tunnel described in Embodiment 1, including:

[0204] A leakage risk module, which is used to determine the gasket leakage risk index R according to the acting stress F of the groundwater pressure at the gasket joint, the aging coefficient P of the gasket, and the segment concrete corrosion coefficient α at the gasket joint, where R = F·α·P.

[0205] A waterproof module, which is used to determine the ultimate waterproof ability Z of the gasket J .

[0206] An early warning module, which is used to compare the gasket leakage risk index with the ultimate waterproof ability. If R ≤ Z J , then give an early warning and take waterproof measures

[0207] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0208] The above-described embodiments only represent the implementation manners of the invention. The protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention.

Claims

1. A method for predicting the leakage risk of an anchoring gasket in a shield tunnel, characterized in that, Including: Determine the gasket leakage risk index R according to the acting stress F of groundwater pressure at the gasket joint, the aging coefficient P of the gasket, and the corrosion coefficient α of the segment concrete at the gasket joint, where R = F·α·P; Determine the ultimate waterproofing ability Z of the gasket J ; Compare the gasket leakage risk index with the ultimate waterproofing ability. If R ≤ Z J , then give an early warning and take waterproofing measures.

2. The method for predicting the leakage risk of the anchored gasket in a shield tunnel according to claim 1, wherein Determine the ultimate waterproofing ability of the gasket in the following manner: Through a water seepage test, simulate the waterproofing ability of the joint part of two gaskets under different opening amounts and offset amounts, and obtain the data of the waterproofing ability, opening amount, and offset amount of the gasket; Perform data fitting on the obtained data of the waterproofing ability, opening amount, and offset amount of the gasket to obtain a waterproofing ability relationship; According to the characteristics of water pressure action, divide the waterproofing failure process of the gasket into multiple stages, and divide the stage of water body wedging into the contact surface between two gaskets into the water wedging stage; and determine the waterproofing ability of the gasket in the water wedging stage as the ultimate waterproofing ability of the gasket; According to the depth of the underground environment where the gasket is located and the gasket model, determine the opening amount and offset amount of the gasket in the water wedging stage by referring to materials, and substitute them into the waterproofing ability relationship to obtain the specific value of the ultimate waterproofing ability of the gasket.

3. The method for predicting the leakage risk of the anchored gasket in a shield tunnel according to claim 1, wherein, The acting stress F of groundwater pressure at the gasket gap is obtained in the following manner: During the prefabrication process of the gasket, an optical fiber is provided along the layout direction of the gasket on the top of the water-facing side of the gasket, and the acting stress of groundwater pressure at the gasket gap is obtained through the optical fiber sensor at the end of the optical fiber.

4. The method for predicting the leakage risk of the anchored gasket in a shield tunnel according to claim 1, wherein, The corrosion coefficient α of the segment concrete at the gasket joint is obtained in the following manner: Classify into three types of environments according to the climate zone of the construction site, the soil permeability of the concrete, and the conditions of wet-dry alternation and freeze-thaw alternation; Then, according to the environmental category and the evaluation standard of the corrosiveness of groundwater to building materials, determine the corrosion coefficients of segment concrete under the conditions of slight corrosion, weak corrosion, medium corrosion, and strong corrosion in the three types of environments.

5. The method for predicting the leakage risk of the anchor-type gasket in the shield tunnel according to claim 1, characterized in that, The gasket includes a corner connection section (10) and a straight section (20); both ends of the corner connection section (10) are respectively connected to the straight section (20) and form a chamfer structure; A deformation through-hole is provided in the corner connection section (10); and at least two rows of deformation through-holes are provided in the corner connection section (10), and the number of rows of deformation through-holes in the corner connection section (10) is less than the number of rows of deformation through-holes in the straight section (20).

6. The method for predicting the leakage risk of the shield tunnel anchoring gasket according to claim 6, wherein, The straight section (20) includes a straight section body (200) and anchoring legs (21); the anchoring legs (21) are integrally formed with the straight section body (200), and the anchoring legs (21) are provided on both sides of the straight section body (200) and are located at the bottom of the straight section body (200).

7. The method for predicting the leakage risk of the anchor-type gasket in a shield tunnel according to claim 6, characterized in that, The first row of corner deformation through-holes of the corner connection section (10) is located at the bottom of the corner connection section (10); and the first row of corner deformation through-holes includes a first bottom buffer hole (11) and a second bottom buffer hole (12), and the two bottom buffer holes have the same structure but different heights, forming a hierarchical buffer.

8. The method for predicting the leakage risk of the shield tunnel anchoring gasket according to claim 8, characterized in that, Multiple rows of deformation through-holes are provided on the straight section body (200); the first row of straight section deformation through-holes located at the bottom of the straight section body (200) has the same structure as the first row of corner deformation through-holes at the bottom of the corner connection section (10) and is at the same horizontal position.

9. The method for predicting the leakage risk of the anchoring gasket in a shield tunnel according to claim 6, characterized in that, The opening ratio k on the corner connecting section (10) follows the following design rules: Wherein, A0 is the cross-sectional area of the outer shape of the corner connection section, H0 is the height of the outer shape of the corner connection section, A 1,i is the cross-sectional area of the i-th hole type on the outer shape of the corner connection section, H 1,i is the height of the i-th hole type on the corner connection section, C 孔型,i is the correction coefficient of the i-th hole type on the corner connection section, C 缓冲 is the grading buffer correction coefficient of the bottom deformation through hole on the corner connection section, and n is the number of the i-th hole type on the corner connection section; Furthermore, the opening ratio on the straight segment body (200) reuses the design rule of the opening ratio on the corner connecting segment (10).

10. A leakage risk prediction system for an anchor-type gasket in a shield tunnel, characterized in that, The method for predicting leakage risk of anchored seals in shield tunnels according to any one of claims 1 to 9 comprises: The leakage risk module is used to determine the gasket leakage risk index R according to the stress F of the groundwater pressure at the gasket joint, the aging coefficient P of the gasket and the corrosion coefficient α of the segment concrete at the gasket joint, R = F·α·P; A waterproof module for determining the ultimate waterproof capacity Z of a gasket J ; An early warning module, which is used to compare the gasket leakage risk index with the ultimate waterproofing ability. If R ≤ Z J , then give an early warning and take waterproofing measures.

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