A method for anti-cracking and anti-seepage construction of side walls of working shafts of ultra-large diameter shield tunnels

Abstract

The invention discloses a method for anti-cracking and anti-seepage construction of the side wall of a working shaft of an ultra-large diameter shield tunnel, which belongs to the technical field of tunnel construction and comprises the following steps: pre-treating the maintenance structure, ring frame beam and side wall outer formwork of the working shaft side wall to be cast; adjusting and controlling the mold entry temperature of self-compacting and highly crack-resistant concrete cast in the working shaft side wall based on the average daily temperature during construction and the length of a single side wall of the working shaft; adjusting and controlling the casting rate of the self-compacting and highly crack-resistant concrete according to different casting positions of the working shaft side wall, and controlling the maximum temperature rise value of the concrete center in the working shaft side wall according to the length of the single side wall of the working shaft; and continuing to cast a certain amount of the self-compacting and highly crack-resistant concrete through a feed port after the casting of the working shaft side wall is completed, so that the concrete liquid level height in the feed port and the exhaust hole is higher than the concrete liquid level height in the working shaft side wall, effectively suppressing the occurrence of penetrating shrinkage cracks in the concrete and achieving dense filling.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel construction, and in particular relates to a method for anti-cracking and anti-seepage construction of side walls of a working shaft of an ultra-large diameter shield tunnel. Background Art

[0002] Underwater tunnels are key control projects in the construction of numerous underwater highways, subway tunnels, and municipal engineering projects. In recent years, the scale of underwater tunnel construction has grown rapidly, and shield tunneling has become a key option for crossing rivers, lakes, and oceans. With economic and social development, increasing demand for transportation, and the development of core equipment, the diameter of shield tunnels has increased. The working shaft, which serves as the starting and receiving point for the shield machine and the exchange of personnel, machines, and materials, is a crucial component of shield tunnels. For ultra-large diameter shield tunnels with diameters exceeding 14 meters, the large structural dimensions, deep excavation depths, and complex working conditions of the working shafts pose even greater challenges to engineering construction.

[0003] Engineering research on the side walls of similar working pits and similar cast-in-place side wall structures shows that these cast-in-place side wall structures are highly susceptible to through-hole shrinkage cracks during construction, leading to water seepage. Furthermore, the side walls of the working pit are located between the previously cast ring frame beams of the upper and lower layers, or between the ring frame beam and the working pit floor. This effectively means that the side wall concrete is poured within a confined space, making concrete placement and vibration difficult. Furthermore, the interface between the new and old concrete at the top of the side wall is prone to water seepage due to its looseness.

[0004] The shrinkage cracking and leakage caused by the loose combination of new and old concrete have become common quality problems in shield tunnel working shafts. In terms of side wall structure, for ultra-large diameter shield tunnels, due to their large structural dimensions and complex working conditions, and the construction process that usually adopts vertical layering and one-time pouring of loops without segments, the ultra-long, large-volume concrete poured in this step-by-step manner has a high risk of cracking, which makes construction difficult and the leakage problem more prominent. In terms of concrete materials, there is a contradiction between crack control and dense filling. Due to the strong constraints and the long one-time pouring length, the difficulty of controlling cracks in the side walls of ultra-large diameter shield tunnel working shafts is much higher than that of similar cast-in-place tunnels and underground station side walls. In order to reduce the risk of concrete cracking, it is necessary to limit the maximum amount of cementitious materials used in concrete, making the dense filling of the concrete side walls of ultra-large diameter shield tunnel working shafts much more difficult than the self-compacting concrete commonly used in steel tube arch bridges and steel shell immersed tubes. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for anti-cracking and anti-seepage construction of the side walls of the working shaft of an ultra-large diameter shield tunnel, effectively reducing the difficulty of concrete construction of the side wall structure of the working shaft of an ultra-large diameter shield tunnel, inhibiting the occurrence of through-shrinkage cracks in the concrete, achieving dense filling, and solving the problems of cracking and leakage.

[0006] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0007] The present invention provides a method for anti-cracking and anti-seepage construction of the side wall of a working shaft of an ultra-large diameter shield tunnel, comprising the following steps:

[0008] Pre-treat the maintenance structure, ring frame beam and side wall outer formwork of the working pit side wall to be poured;

[0009] Based on the average daily temperature during construction and the length of the single-side wall of the working pit, the temperature of the self-compacting, high-crack-resistant concrete poured into the side wall of the working pit is adjusted and controlled;

[0010] According to the different pouring locations of the working pit side wall, the pouring rate of the self-compacting, highly crack-resistant concrete is adjusted accordingly, and the maximum temperature rise value of the concrete center in the working pit side wall is controlled according to the length of the single side wall of the working pit;

[0011] After the side wall of the working pit is poured, a certain amount of the self-compacting, highly crack-resistant concrete is continued to be poured through the discharge port, so that the concrete liquid level in the discharge port and the exhaust hole is higher than the concrete liquid level in the side wall of the working pit.

[0012] Furthermore, the method for pre-treating the maintenance structure, ring frame beam, and side wall outer formwork of the working pit side wall to be cast includes the following steps:

[0013] A protective material is provided on the surface of the maintenance structure adjacent to the inner side surface of the side wall of the working pit to prevent direct contact between the maintenance structure and the inner side surface of the side wall of the working pit;

[0014] A plurality of feed openings and a plurality of exhaust holes are provided on the ring frame beam at the top of the side wall of the working pit, and the lower surface of the ring frame beam is roughened;

[0015] A number of exhaust holes are opened on the outer formwork of the side wall of the working pit within a certain distance from the adjacent top ring frame beam.

[0016] Furthermore, the self-compacting, high crack resistance concrete performance must meet the following conditions:

[0017] The strength grade shall not exceed C45, the slump expansion in the mold shall be 600-700mm, T500 shall not be greater than 6s, the inverted slump time shall not be greater than 6s, the 7d adiabatic temperature rise shall not be greater than 47°C, the ratio of the 1d adiabatic temperature rise value to the 7d adiabatic temperature rise value shall not be greater than 50%, the 7d autogenous volume deformation shall not be less than 250με, the 28d autogenous volume deformation shall not be less than 220με, and the 56d autogenous volume deformation shall not be less than 200με.

[0018] Furthermore, the self-compacting, highly crack-resistant concrete comprises the following raw materials and weight fractions:

[0019] 180-260 parts by mass of cement;

[0020] 100-150 parts by mass of fly ash;

[0021] 0 to 50 parts by mass of slag powder;

[0022] 830-950 parts by mass of fine aggregate;

[0023] 830-950 parts by mass of coarse aggregate;

[0024] 36 to 50 parts by mass of an anti-cracking agent;

[0025] 40-50 parts by mass of a rheology-modifying material;

[0026] 4 to 6 parts by mass of water reducer;

[0027] and 150 to 180 parts by mass of mixing water.

[0028] Furthermore, the protective material includes spraying waterproof coating, or paving cloth-like woven fabric, or paving polymer waterproof roll.

[0029] Furthermore, the control of the mold temperature includes the following steps:

[0030] Adjust the mold entry temperature of the self-compacting, high crack resistance concrete described in the working pit side wall according to the average daily temperature during construction and the length of the single side wall of the working pit:

[0031] When the length of a single side wall is ≤30m, the mold entry temperature should be ≤ the average daily temperature and not greater than 28℃;

[0032] When the length of a single side wall is greater than 30m, the temperature entering the mold shall be ≤ the average daily temperature and not greater than 25℃.

[0033] Furthermore, the method for adjusting and controlling the pouring rate of the concrete includes:

[0034] Control the pouring height rate of the middle and lower walls of the working pit side wall to no more than 0.4m / h. When it is 30 to 50cm away from the waterstop at the top of the ring frame beam, let it stand for 1 to 3h, and then continue pouring at a pouring height rate of no more than 0.2m / h. Control the maximum horizontal flow distance of concrete to no more than 6m.

[0035] Furthermore, the maximum temperature rise of the concrete center in the side wall of the working shaft is regulated and controlled including:

[0036] When the length of the single side wall of the working pit is not more than 30m, the maximum temperature rise of the concrete center shall be controlled not to exceed 35℃;

[0037] When the length of a single side wall of the working pit is greater than 30m, the maximum temperature rise of the concrete center shall be controlled not to exceed 32°C.

[0038] Furthermore, the control of the maximum temperature rise in the center of the concrete also includes burying a number of cooling water pipes in the side walls.

[0039] Furthermore, during the pouring process of the working pit side wall, the maximum cooling rate of the geometric center point of the working pit side wall is controlled to be no more than 3°C / d and the temperature difference between the inside and outside of the concrete is controlled to be no more than 15°C.

[0040] Furthermore, the discharge port is arranged on the ring frame beam at the top of the side wall of the working pit, and is opened between the central axis of the waterstop and the outer end of the waterstop along the extension direction of the waterstop.

[0041] Furthermore, the distance between adjacent discharge openings is no more than 2m.

[0042] Furthermore, at least two rows of exhaust holes are provided on the waterstop of the ring frame beam along the extending direction of the waterstop.

[0043] Furthermore, the diameter of the exhaust holes is not less than 10 cm, the horizontal spacing between adjacent exhaust holes along the length direction of the ring frame beam is not greater than 2 m, and the horizontal spacing between two adjacent rows of exhaust holes along the thickness direction of the ring frame beam is not greater than 0.5 m.

[0044] Furthermore, the feed opening is located in the distribution direction of one column of the at least two columns of exhaust holes and is alternately spaced with the exhaust holes.

[0045] Furthermore, the lower surface of the ring frame beam is roughened to a depth of 0.5 to 1.5 cm, and the roughening depth does not exceed 3 cm.

[0046] Furthermore, a plurality of exhaust holes are provided on the outer formwork of the side wall of the working pit within a distance of 0 to 10 cm from the adjacent top ring frame beam.

[0047] Furthermore, the anti-cracking agent in the concrete component is High-efficiency anti-cracking agent for concrete (temperature control, anti-seepage).

[0048] Furthermore, the water reducing agent in the concrete composition is Self-compacting concrete admixture.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel provided by the present invention has been improved and innovated in multiple construction processes and key indicators, such as the contact mode of the retaining structure, the opening of a feed port and an exhaust hole on the ring frame beam, the roughening treatment of the bottom surface of the ring frame beam, the concrete pouring rate and the temperature entering the mold, the maximum temperature rise value of the concrete center, the height of the concrete liquid level in the feed port and the exhaust hole being higher than the height of the concrete liquid level in the side wall of the working shaft, so as to densely fill the concrete of the side wall structure of the working shaft, effectively reduce the difficulty of concrete construction of the side wall structure of the working shaft of an ultra-large diameter shield tunnel, inhibit the occurrence of through shrinkage cracks in the concrete, achieve dense filling, and solve the problems of cracking and leakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 This is a flow chart of a method for anti-cracking and anti-seepage construction of side walls of a working shaft of an ultra-large diameter shield tunnel provided in accordance with an embodiment of the present invention;

[0052] Figure 2 2. It is a schematic diagram of a front view of the side wall structure of the starting working shaft of an ultra-large diameter shield tunnel along the direction of the shield tunnel opening according to an embodiment of the present invention;

[0053] Figure 3 2. It is a side view schematic diagram of the arrangement of cooling water pipes in the second layer side wall of the starting working shaft of an ultra-large diameter shield tunnel according to an embodiment of the present invention;

[0054] Figure 4 2. It is a side view schematic diagram of the arrangement of cooling water pipes in the fourth layer side wall of the starting working shaft of an ultra-large diameter shield tunnel according to an embodiment of the present invention;

[0055] Figure 5 The figure is a top view schematic diagram of the arrangement of the feed opening and the exhaust hole of the ring frame beam at the top of the side wall of the working shaft of an ultra-large diameter shield tunnel according to an embodiment of the present invention.

[0056] In the picture:

[0057] 1. Working pit bottom plate; 2. First-layer side wall; 3. First-layer ring frame beam; 4. Second-layer side wall; 5. Second-layer ring frame beam; 6. Third-layer side wall; 7. Third-layer ring frame beam; 8. Fourth-layer side wall; 9. Fourth-layer ring frame beam; 10. Exhaust hole; 11. Feeding port; 12. Waterstop; 13. Cooling water pipe; 14. Tunnel portal. DETAILED DESCRIPTION

[0058] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0059] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0060] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0061] like Figure 1 As shown, an embodiment of the present invention provides a method for anti-cracking and anti-seepage construction of the side wall of an ultra-large diameter shield tunnel working shaft, comprising the following method steps:

[0062] Pre-treat the maintenance structure, ring frame beam and side wall outer formwork of the working pit side wall to be poured;

[0063] Based on the average daily temperature during construction and the length of the single-side wall of the working pit, the temperature of the self-compacting, high-crack-resistant concrete poured into the side wall of the working pit is adjusted and controlled;

[0064] According to the different pouring locations of the working pit side wall, the pouring rate of the self-compacting, highly crack-resistant concrete is adjusted accordingly, and the maximum temperature rise value of the concrete center in the working pit side wall is controlled according to the length of the single side wall of the working pit;

[0065] After the side wall of the working pit is poured, a certain amount of the self-compacting, highly crack-resistant concrete is poured through the discharge port 11 so that the concrete liquid level in the discharge port 11 and the exhaust hole 10 is higher than the concrete liquid level in the side wall of the working pit.

[0066] In some embodiments, a method for pre-treating the maintenance structure, ring frame beam, and side wall outer formwork of the working pit side wall to be cast includes the following steps:

[0067] A protective material is provided on the surface of the maintenance structure adjacent to the inner side surface of the side wall of the working pit to prevent direct contact between the maintenance structure and the inner side surface of the side wall of the working pit;

[0068] A plurality of feed openings 11 and a plurality of exhaust holes 10 are provided on the ring frame beam at the top of the side wall of the working pit, and the lower surface of the ring frame beam is roughened;

[0069] A plurality of exhaust holes 10 are provided on the outer formwork of the side wall of the working pit within a certain distance from the adjacent top ring frame beam.

[0070] In some embodiments, the self-compacting, highly crack-resistant concrete properties must meet the following conditions:

[0071] The strength grade shall not exceed C45, the slump expansion in the mold shall be 600-700mm, T500 shall not be greater than 6s, the inverted slump time shall not be greater than 6s, the 7d adiabatic temperature rise shall not be greater than 47°C, the ratio of the 1d adiabatic temperature rise value to the 7d adiabatic temperature rise value shall not be greater than 50%, the 7d autogenous volume deformation shall not be less than 250με, the 28d autogenous volume deformation shall not be less than 220με, and the 56d autogenous volume deformation shall not be less than 200με.

[0072] Specifically, the self-compacting, highly crack-resistant concrete includes the following raw materials and weight fractions:

[0073] 180-260 parts by mass of cement;

[0074] 100-150 parts by mass of fly ash;

[0075] 0 to 50 parts by mass of slag powder;

[0076] 830-950 parts by mass of fine aggregate;

[0077] 830-950 parts by mass of coarse aggregate;

[0078] 36 to 50 parts by mass of an anti-cracking agent;

[0079] 40-50 parts by mass of a rheology-modifying material;

[0080] 4 to 6 parts by mass of water reducer;

[0081] and 150 to 180 parts by mass of mixing water.

[0082] Based on the stress criterion, the cracking risk coefficient is calculated based on the ratio of the tensile stress caused by concrete shrinkage to its tensile strength, taking into account factors such as materials (raw materials, concrete mix ratio and properties), structure (external constraints, structural type), construction (casting length, mold entry temperature), and environmental (air temperature) involved in specific working conditions. The cracking risk coefficient is controlled to not exceed 0.7, and relevant anti-cracking technical solutions are derived, such as control indicators such as concrete adiabatic temperature rise, deformation, mold entry temperature, and casting length. In some embodiments, the above indicators are obtained based on the evaluation results of the "Software Copyright Registration No. 1470077" "Early Crack Risk Assessment and Analysis Software for Structural Concrete" developed based on a multi-factor coupling model of hydration-temperature-temperature-humidity, and extensive engineering practice.

[0083] On the basis of meeting the above-mentioned crack resistance indicators, the embodiment of the present invention achieves the synergy of crack resistance and fluidity by adopting crack resistance-enhancing functional materials and special chemical admixtures for fluidity regulation, and prepares a self-compacting, highly crack-resistant concrete for the concrete crack-resistant and anti-seepage construction method of the side wall structure of the working shaft of the ultra-large diameter shield tunnel in the embodiment of the present invention, and proposes key indicators and solutions for the construction process from the aspects of contact mode with the enclosing structure, concrete pouring rate and material distribution.

[0084] (1) Preparation of self-compacting, highly crack-resistant concrete and steps for controlling the temperature of the concrete before pouring into the mould.

[0085] First, the mix ratio of self-compacting and crack-resistant concrete is determined.

[0086] Based on the specific working conditions of the working pit sidewall, while ensuring that it does not crack, concrete crack resistance performance indicators are derived. Indoor crack resistance performance indicators include adiabatic temperature rise and autogenous volume deformation, while on-site and physical structural crack resistance performance indicators include mold entry temperature, temperature rise, cooling rate, and internal and external temperature difference. In some embodiments, these indicators are obtained using the software "Software Copyright Registration No. 1470077," developed using a multi-factor coupling model of hydration-temperature-temperature-humidity, to develop "Early-Life Cracking Risk Assessment and Analysis Software for Structural Concrete."

[0087] In some embodiments, under the premise of meeting the indoor crack resistance performance index, self-compacting, highly crack-resistant concrete is designed and determined based on construction performance indicators such as the slump expansion of fresh concrete into the mold, T500, and inverted slump time, as shown in Table 1.

[0088] Table 1 Mix proportions of self-compacting and high crack resistance concrete

[0089] Unit: kg / m 3

[0090] cement fly ash slag powder Anti-cracking agent Rheology modifiers fine aggregate coarse aggregate water reducer Mixing water 180～260 100～150 0～50 36～50 40～50 830～950 830～950 4～6 150～180

[0091] As for the selection of raw materials, the properties of general-purpose Portland cement shall comply with the requirements of GB 175 "General-purpose Portland Cement" and CCES01 in the "Guidelines for Durability Design and Construction of Concrete Structures". The properties of medium- and low-heat Portland cements shall comply with the requirements of GB / T 200 "Medium-heat Portland Cement, Low-heat Portland Cement". The properties of fly ash shall comply with the requirements of Grade II and above specified in GB / T 1596 "Fly Ash for Cement and Concrete". The properties of slag powder shall comply with the requirements of Grade S95 and above specified in GB / T 18046 "Granulated Blast Furnace Slag for Cement, Mortar and Concrete" and CCES01 in the "Guidelines for Durability Design and Construction of Concrete Structures". The fine aggregate shall be natural zone II medium sand with a mud content not exceeding 2.0% and a mud block content not exceeding 1.0%. The properties of coarse aggregate shall comply with the requirements of GB / T 18046 "Pebble and Crushed Stone for Construction". The requirements for 5-20 mm continuous graded crushed stone specified in 14685 are that the loose stacking porosity shall not exceed 43%; the performance of the rheology-modified material shall meet the requirements of "Compound Admixtures for Concrete" (JG / T 486).

[0092] Among them, the anti-cracking agent uses the HME-V concrete (temperature control, anti-seepage) high-efficiency anti-cracking agent produced by Jiangsu Subote New Materials Co., Ltd., which is a compound of calcium-magnesium composite expansive agent and concrete hydration temperature rise inhibitor. The performance of the calcium-magnesium composite expansive agent should comply with the requirements of "Calcium-magnesium composite expansive agent for concrete" T / CECS 10082, and the performance of the concrete hydration temperature rise inhibitor should comply with the requirements of "Concrete hydration temperature rise inhibitor" JC / T 2608.

[0093] Among them, the water reducer is produced by Jiangsu Subote New Materials Co., Ltd. Self-compacting concrete admixture has excellent thickening effect. While ensuring the control of concrete workability, its shrinkage ratio does not exceed 100%.

[0094] It should be noted that the mixing water includes solid flake ice for cooling purposes, rather than being limited to liquid water.

[0095] In some embodiments, the performance index requirements of self-compacting, high crack resistance concrete are shown in Table 2.

[0096] Table 2 Properties of self-compacting and high crack resistance concrete

[0097]

[0098] As understood by those skilled in the art, the adiabatic temperature rise of concrete is tested according to the "Standard for Test Methods for Ordinary Concrete Mixtures" (GB / T 50080). The ratio of the adiabatic temperature rise values ​​at 1 day to 7 days is calculated according to the "Technical Specification for Control of Shrinkage Cracks of Cast-in-Place Concrete in Open-Cut Cast-In-Place Tunnels" (DB 32 / T 3947). Autogenous volume deformation is tested according to the non-contact method in the "Standard for Test Methods for Long-Term Performance and Durability of Ordinary Concrete" (GB / T 50082), with the zero point being the initial setting of the concrete. A 7-day autogenous volume deformation ≥ 250 με indicates "expansion deformation of not less than 250 με," and the same applies to 28 and 56 days. Slump expansion and T500 are tested according to the "Technical Specification for Application of Self-Compacting Concrete" (JGJ / T 283). The emptying time of the inverted slump cone is tested according to the "Standard for Test Methods for Ordinary Concrete Mixtures" (GB / T 50080).

[0099] Secondly, the temperature requirements for self-compacting and high crack-resistant concrete entering the mold.

[0100] Adjust the temperature of the side wall concrete entering the mold according to the average daily temperature during construction and the length of the single side wall. The specific requirements are as follows:

[0101] When the length of a single side wall is ≤30m, the mold entry temperature should be ≤ the average daily temperature and not greater than 28℃;

[0102] When the length of a single side wall is greater than 30m, the temperature entering the mold shall be ≤ the average daily temperature and not greater than 25℃.

[0103] In order to control the temperature of concrete entering the mold, measures such as lowering the temperature of raw materials, replacing mixing water with flake ice, and wrapping the tank truck can be adopted.

[0104] (2) The construction process control of concrete crack resistance and anti-seepage of the side wall structure of the working shaft of an ultra-large diameter shield tunnel involves the control of three aspects of construction process:

[0105] (1) Treatment of the external structure adjacent to the side wall of the working pit, including the maintenance structure on the inner side of the side wall of the working pit and the ring frame beam adjacent to the top.

[0106] The surface of the maintenance structure adjacent to the inner side of the working pit side wall is sprayed with waterproof paint with a thickness of not less than 3mm, and / or paved with cloth-like woven fabric with a thickness of not less than 3mm, and / or paved with polymer waterproof membrane with a thickness of not less than 1.5mm, to avoid direct contact between the maintenance structure and the working pit side wall, so as to reduce external constraints and reduce the risk of cracking of the working pit side wall.

[0107] The lower surface of the ring frame beam at the top of the side wall of the working pit is roughened so that its construction depth is 0.5 to 1.5 cm and the roughening depth does not exceed 3 cm, so as to reduce the interface defects between the new and old concrete and improve the meshing quality. This is because if the construction depth and the roughening depth are too small, the new and old concrete cannot be effectively meshed, and if the construction depth and the roughening depth are too large, it is not conducive to the removal of top bubbles and the dense filling of the slurry.

[0108] Due to the concrete distribution requirements, a feed opening 11 is required on the ring frame beam, along with an exhaust hole 10. The exhaust hole 10 can also serve as an observation hole or auxiliary vibration hole when necessary. Despite the provision of feed opening 11 and exhaust holes 10 on the ring frame beam, the exhaust path is still limited for the side walls of this ultra-long, large-volume facade structure cast in a sealed space. Therefore, exhaust holes 10 are further required within a height range of 0 to 10 cm from the top ring frame beam, located between the side wall outer formwork and the top.

[0109] (2) Concrete pouring rate and distribution.

[0110] In order to make the concrete fill as dense as possible and expel bubbles, on the one hand, the pouring rate should be controlled, especially when the top of the side wall is close to the ring frame beam area, the pouring rate should be reduced to facilitate the discharge of bubbles and the dense filling of concrete. The specific requirements are to control the pouring height rate of the lower wall to no more than 0.4m / h, and let it stand for 1 to 3 hours at 30 to 50cm away from the water stop at the top of the ring frame beam. After that, the pouring is completed at a rate of no more than 0.2m / h. Letting it stand for 1 to 3 hours allows the concrete to undergo sufficient plastic settlement.

[0111] After the side wall of the working pit is poured, concrete should continue to be poured through the discharge port 11 so that the concrete overflows in other discharge ports 11 or exhaust holes 10, and the concrete liquid level in the discharge port 11 and the exhaust hole 10 should be at least 1m higher than the liquid level of the side wall of the working pit. This measure is also to ensure that the top concrete of the side wall of the working pit and the ring frame are densely filled.

[0112] (3), temperature control process.

[0113] From the perspective of controlling the risk of concrete cracking, it is proposed to evaluate the hydration-temperature-humidity-constraint multi-factor coupling model or conduct model tests to obtain the maximum temperature rise value of the solid structure of the working shaft side wall:

[0114] When the length of a single side wall is not more than 30m, the maximum temperature rise of the concrete center should be controlled to not exceed 35°C. If necessary, measures such as burying cooling water pipes 13 can be taken;

[0115] When the length of a single side wall is greater than 30m, the maximum temperature rise of the concrete center should be further controlled not to exceed 32°C, and the spacing between cooling water pipes can be increased by 13 if necessary.

[0116] In some embodiments, the maximum cooling rate of the geometric center point of the working shaft side wall structure is controlled to be no more than 3°C / d, and the temperature difference between the inside and outside of the concrete is no more than 15°C.

[0117] The following describes the concrete crack-resistant and anti-seepage construction method for the side wall structure of the working shaft of an ultra-large diameter shield tunnel provided by the present invention through specific construction cases and experimental data.

[0118] Example 1

[0119] The anti-cracking and anti-seepage construction method provided by the present invention is applied to Figure 2 In the side wall of the working shaft of the starting portal 14 of a certain river crossing passage shown in the figure, since the diameter of the shield tunnel exceeds 15m, the working shaft is 28m long and 53.6m wide, the side wall is 1.5m thick, and the foundation pit depth exceeds 27m. It is poured vertically in 4 layers and the circumferential pouring is completed in one time. The concrete design grade is C40P12.

[0120] As a schematic diagram of this embodiment, the working pit side wall structure includes a working pit bottom plate 1, a first-layer side wall 2, a second-layer side wall 4, a third-layer side wall 6, a fourth-layer side wall 8, a first-layer ring frame beam 3, a second-layer ring frame beam 5, a third-layer ring frame beam 7, and a fourth-layer ring frame beam 9.

[0121] Among them, the second-layer side wall 4 and the third-layer side wall 6 have a single-side length of 28m, and the one-time casting length reaches; the fourth-layer side wall 8 has a single-side length of 53.6m, and the one-time casting length reaches 120m.

[0122] This embodiment will use the second and fourth floors as objects to introduce the application of the anti-cracking and anti-seepage construction method provided by the present invention.

[0123] (1) Related pretreatment work in the side wall structure of the working shaft.

[0124] First, a waterproof coating with a thickness of not less than 3 mm is sprayed on the surface of the enclosure structure, and the lower surface of the ring frame beam at the top of the side wall is roughened so that its structural depth is about 1 cm and the roughening depth is about 2 cm.

[0125] Next, the material discharge port 11 and the exhaust hole 10 are arranged.

[0126] The blanking port 11 and the exhaust hole 10 in the ring frame beam are arranged as follows Figure 5 As shown, 200mm diameter steel pipes are used as feed openings 11, spaced 2m apart. 100mm diameter PVC pipes are used as exhaust holes 10, with two rows of exhaust holes 10 arranged. Along the length of the ring frame beam, the exhaust holes 10 aligned with the feed openings 11 are spaced 2m apart, while the spacing of the other row of exhaust holes is 1m apart. The horizontal spacing between the two rows of exhaust holes 10 is 0.5m.

[0127] Finally, an exhaust hole 10 with a diameter of 6 cm is set within a height range of about 8 cm from the top ring frame beam on the side wall outer formwork, and the horizontal spacing of the exhaust holes 10 is 0.8 m.

[0128] (2) Self-compacting, highly crack-resistant concrete and temperature control when entering the mold.

[0129] This step includes the limitations of the preparation materials and properties of self-compacting, highly crack-resistant concrete, as well as the control of its mold entry temperature.

[0130] Specifically, the first is the performance requirements of self-compacting and highly crack-resistant concrete.

[0131] Select high quality self-compacting and high crack resistance concrete raw materials including cement, fly ash, fine aggregate, coarse aggregate, anti-cracking agent, viscosity modifier, Self-compacting concrete admixture: Self-compacting, highly crack-resistant concrete was prepared by mixing according to the amounts shown in Table 3 below.

[0132] Table 3 Mix proportions of self-compacting and high crack resistance concrete

[0133] Unit: kg / m 3

[0134] cement fly ash Anti-cracking agent Rheology modifiers fine aggregate coarse aggregate water reducer Mixing water 225 135 45 45 853 925 4.5 162

[0135] The performance test results of the self-compacting, high crack resistance concrete are shown in Table 4.

[0136] Table 2 Properties of self-compacting and high crack resistance concrete

[0137]

[0138]

[0139] The second is to control the temperature of self-compacting, highly crack-resistant concrete entering the mold.

[0140] In this embodiment, when the second layer of side wall 4 is being constructed, the average daily temperature is about 26°C, and when the fourth layer of side wall 8 is being constructed, the average daily temperature is about 24°C.

[0141] Therefore, the temperature of the second layer side wall 4 entering the mold is controlled to be ≤26°C, and the temperature of the fourth layer side wall 8 entering the mold is controlled to be ≤24°C.

[0142] To this end, measures such as spray cooling in the silo, adding 70 to 80 kg of flake ice per cubic meter to replace mixing water, wrapping the tank trucks, and setting up awnings at the tank truck unloading area were taken.

[0143] The third is the control of the temperature rise of the side wall concrete and the temperature difference between the inside and the outside.

[0144] In this embodiment, according to the software registration number 1470077 "Structural Concrete Early Cracking Risk Assessment and Analysis Software", if no measures are taken for the aforementioned self-compacting, high crack resistance concrete, the temperature rise of the side wall of the physical working shaft will exceed 35°C.

[0145] Since the maximum length of one side of the second layer side wall 4 is 28m, cooling water pipes 13 with a spacing of 1m are set in the second layer side wall 4. Figure 3 The maximum length of a single side of the fourth layer side wall 8 is 53.6m, so cooling water pipes 13 with a minimum spacing of 0.5m are set in the fourth layer side wall 8, as shown in FIG. Figure 4 shown.

[0146] The side walls of the working pit are made of 1.8cm thick wooden formwork and are located in a deep foundation pit with relatively poor air circulation. The evaluation results show that the temperature difference between the inside and outside of the concrete does not exceed 15°C, so no additional insulation measures were taken.

[0147] The fourth is the pouring of concrete.

[0148] The pouring height rate of the lower wall is controlled to be no more than 0.4m / h. When it is 50cm away from the water stop 12 at the top of the ring frame beam, it is allowed to stand for 2 hours. After that, the pouring is completed at a rate of 0.2m / h, and the maximum horizontal flow distance of the concrete is controlled to be no more than 6m. Under normal circumstances, the "one pouring every other" method is adopted, that is, the concrete is poured at every other feed opening 11, and the maximum horizontal distance of the concrete is 4m. When it is inconvenient to pour concrete in special areas, the "two pouring every other" method is adopted, and the maximum horizontal distance of the concrete is 6m. Since the height of the ring frame beam is greater than 1.5m, at the end of the final pouring, all the feed openings 11 and the exhaust holes 10 in the ring frame beam are poured and filled.

[0149] According to the regulation of various parameters in the aforementioned anti-cracking and anti-seepage construction method of the present invention, it can be seen that all indicators in Table 3 meet the requirements. After the side walls of the working well are cast according to the technical solution provided by the present invention, no problems such as penetrating shrinkage cracks, looseness and leakage occur.

[0150] Table 3 Key parameters for temperature monitoring of self-compacting and high crack resistance concrete

[0151] concrete Mold temperature Maximum temperature rise Temperature difference between inside and outside Cooling rate Second layer side wall 23.5℃ 34℃ 12℃ 1.9℃ / d Fourth floor side wall 22.5℃ 30℃ 10℃ 2.2℃ / d

[0152] Example 2

[0153] The anti-cracking and anti-seepage construction method provided by the present invention is applied to the side wall of a receiving working shaft of a river crossing channel. Since the diameter of the shield tunnel exceeds 15m, the working shaft is 28m long and 55.2m wide, the side wall is 1.5m thick, and the foundation pit depth exceeds 31m. The vertical pouring is divided into 4 layers, and the circumferential pouring is completed in one time. The concrete design grade is C45P12.

[0154] Among them, the single-side length of the fourth-floor side wall 8 reaches 55.2m, and the one-time casting length exceeds 120m.

[0155] This embodiment will take the fourth floor as the object to introduce the application of the anti-cracking and anti-seepage construction method provided by the present invention.

[0156] (1) Related pretreatment work in the side wall structure of the working shaft.

[0157] First, a waterproof coating with a thickness of about 3.5 mm is sprayed on the surface of the enclosure structure, and the lower surface of the ring frame beam at the top of the side wall is roughened so that its construction depth is about 1.5 cm and the roughening depth is about 2.5 cm.

[0158] Next, the material discharge port 11 and the exhaust hole 10 are arranged.

[0159] 200mm diameter steel pipes were used as feed openings 11, spaced 1.8m apart. 150mm diameter PVC pipes were used as exhaust holes 10, with two rows of exhaust holes 10 arranged. Along the length of the ring frame beam, the exhaust holes 10 aligned with the feed openings 11 were spaced 1.8m apart, while the spacing of the other row of exhaust holes was 0.9m. The horizontal spacing between the two rows of exhaust holes 10 was 0.5m.

[0160] Finally, an exhaust hole 10 with a diameter of 5 cm is set within a height range of about 10 cm from the top ring frame beam on the side wall outer formwork, and the horizontal spacing of the exhaust holes 10 is 1 m.

[0161] (2) Self-compacting, highly crack-resistant concrete and temperature control when entering the mold.

[0162] This step includes the limitations of the preparation materials and properties of self-compacting, highly crack-resistant concrete, as well as the control of its mold entry temperature.

[0163] Specifically, the first is the performance requirements of self-compacting and highly crack-resistant concrete.

[0164] Select high quality self-compacting and high crack resistance concrete raw materials including cement, fly ash, fine aggregate, coarse aggregate, anti-cracking agent, viscosity modifier, Self-compacting concrete admixture: Self-compacting, highly crack-resistant concrete was prepared by mixing according to the amounts shown in Table 4 below.

[0165] Table 4 Mix proportions of self-compacting and high crack resistance concrete

[0166] Unit: kg / m 3

[0167] cement fly ash Anti-cracking agent Rheology modifiers fine aggregate coarse aggregate water reducer Mixing water 260 150 50 40 857 857 5 180

[0168] The performance test results of the self-compacting, high crack resistance concrete are shown in Table 5.

[0169] Table 5 Properties of self-compacting and high crack resistance concrete

[0170]

[0171] The second is to control the temperature of self-compacting, highly crack-resistant concrete entering the mold.

[0172] During the construction of the side wall of the working pit, the average daily temperature was about 20℃.

[0173] Therefore, the temperature of the second layer of side wall 4 entering the mold is controlled to be ≤20°C.

[0174] To this end, measures such as spray cooling in the silo, adding 70kg of flake ice per cubic meter to replace mixing water, and wrapping tank trucks were adopted.

[0175] The third is the control of the temperature rise of the side wall concrete and the temperature difference between the inside and the outside.

[0176] In this embodiment, according to the software registration number 1470077 "Structural Concrete Early Cracking Risk Assessment and Analysis Software", if no measures are taken for the aforementioned self-compacting, high crack resistance concrete, the temperature rise of the side wall of the physical working shaft will exceed 35°C.

[0177] Since the maximum length of a single side of the side wall is 55.2m, cooling water pipes 13 with a minimum spacing of 0.5m are set in the side wall. Figure 4 shown.

[0178] The side walls of the working pit are made of 2.0cm thick wooden formwork and are located in a deep foundation pit with relatively poor air circulation. The evaluation results show that the temperature difference between the inside and outside of the concrete does not exceed 15°C, so no additional insulation measures were taken.

[0179] The fourth is the pouring of concrete.

[0180] The pouring height rate of the lower wall is controlled to be no more than 0.3m / h. When it is 30cm away from the water stop 12 at the top of the ring frame beam, it is allowed to stand for 3 hours. After that, the pouring is completed at a rate of 0.2m / h, and the maximum horizontal flow distance of the concrete is controlled to be no more than 6m. Under normal circumstances, the "one pouring every other" method is adopted, that is, the concrete is poured at every other feed opening 11, and the maximum horizontal distance of the concrete is 4m. When it is inconvenient to pour concrete in special areas, the "two pouring every other" method is adopted, and the maximum horizontal distance of the concrete is 6m. Since the height of the ring frame beam is greater than 1.6m, at the end of the final pouring, all the feed openings 11 and the exhaust holes 10 in the ring frame beam are poured and filled.

[0181] According to the regulation of various parameters in the aforementioned anti-cracking and anti-seepage construction method of the present invention, it can be seen that all indicators in Table 6 meet the requirements. After the side wall of the working pit is cast according to the technical solution provided by the present invention, no problems such as penetrating shrinkage cracks, looseness and leakage occur.

[0182] Table 6 Key parameters for temperature monitoring of self-compacting and high crack resistance concrete

[0183] Mold temperature Maximum temperature rise Temperature difference between inside and outside Cooling rate 19.5℃ 30.2℃ 11℃ 1.7℃ / d

[0184] Example 3

[0185] The anti-cracking and anti-seepage construction method provided by the present invention is applied to the side wall of the starting working shaft of a river crossing channel. Since the diameter of the shield tunnel exceeds 14m, the side wall of the working shaft is 1.3m thick, the maximum single side length is 45.6m, and the concrete design grade is C35P12.

[0186] This embodiment will take the longest fourth-layer side wall 8 cast in a single step as an object to introduce the application of the anti-cracking and anti-seepage construction method provided by the present invention.

[0187] (1) Related pretreatment work in the side wall structure of the working shaft.

[0188] First, a waterproof coating with a thickness of 3 to 3.5 mm is sprayed on the surface of the enclosure structure, and the lower surface of the ring frame beam at the top of the side wall is roughened so that its structural depth is about 1 cm and the roughening depth is about 2.0 cm.

[0189] Next, the material discharge port 11 and the exhaust hole 10 are arranged.

[0190] 200mm diameter steel pipes were used as feed openings 11, spaced 1.5m apart. 100mm diameter PVC pipes were used as exhaust holes 10, with two rows of exhaust holes 10 arranged. Along the length of the ring frame beam, the exhaust holes 10 aligned with the feed openings 11 were spaced 1.5m apart, while the spacing between the other rows was 0.75m. The horizontal spacing between the two rows of exhaust holes 10 was 0.5m.

[0191] Finally, exhaust holes 10 with a diameter of 4 cm are set within a height range of about 8 cm from the top ring frame beam on the side wall outer formwork, and the horizontal spacing of the exhaust holes 10 is 1 m.

[0192] (2) Self-compacting, highly crack-resistant concrete and temperature control when entering the mold.

[0193] This step includes the limitations of the preparation materials and properties of self-compacting, highly crack-resistant concrete, as well as the control of its mold entry temperature.

[0194] Specifically, the first is the performance requirements of self-compacting and highly crack-resistant concrete.

[0195] Select high quality self-compacting and high crack resistance concrete raw materials including cement, fly ash, fine aggregate, coarse aggregate, anti-cracking agent, viscosity modifier, Self-compacting concrete admixture: Self-compacting, highly crack-resistant concrete was prepared by mixing according to the amounts shown in Table 7 below.

[0196] Table 7 Mix proportions of self-compacting and high crack resistance concrete

[0197] Unit: kg / m 3

[0198] cement fly ash slag powder Anti-cracking agent Rheology modifiers fine aggregate coarse aggregate water reducer Mixing water 180 100 50 36 44 890 950 4 150

[0199] The performance test results of the self-compacting, highly crack-resistant concrete obtained are shown in Table 8.

[0200] Table 8 Properties of self-compacting and high crack resistance concrete

[0201]

[0202] The second is to control the temperature of self-compacting, highly crack-resistant concrete entering the mold.

[0203] During the construction of the side wall of the working pit, the average daily temperature was about 29℃.

[0204] Therefore, the temperature of the second layer of side wall 4 entering the mold is controlled to be ≤28°C.

[0205] To this end, measures such as spray cooling in the silo, adding 90kg of flake ice per cubic meter to replace mixing water, wrapping the tank truck, and setting up awnings at the concrete unloading pump were taken.

[0206] The third is the control of the temperature rise of the side wall concrete and the temperature difference between the inside and the outside.

[0207] In this embodiment, according to the software registration number 1470077 "Structural Concrete Early Cracking Risk Assessment and Analysis Software", if no measures are taken for the aforementioned self-compacting, high crack resistance concrete, the temperature rise of the side wall of the physical working shaft will exceed 35°C.

[0208] Since the maximum length of a single side of the side wall is 45.6m, cooling water pipes 13 with a minimum spacing of 0.5m are set in the side wall. Figure 4 shown.

[0209] The side walls of the working pit are made of 1.8cm thick wooden formwork and are located in a deep foundation pit with relatively poor air circulation. The evaluation results show that the temperature difference between the inside and outside of the concrete does not exceed 15°C, so no additional insulation measures were taken.

[0210] The fourth is the pouring of concrete.

[0211] The pouring height rate of the lower wall is controlled to be no more than 0.4m / h. When it is 40cm away from the water stop 12 at the top of the ring frame beam, it is allowed to stand for 1.5h. After that, the pouring is completed at a rate of 0.2m / h, and the maximum horizontal flow distance of the concrete is controlled to be no more than 6m. Under normal circumstances, the "one pouring every other" method is adopted, that is, the concrete is poured at every other feed opening 11, and the maximum horizontal distance of the concrete is 4m. When it is inconvenient to pour concrete in special areas, the "two pouring every other" method is adopted, and the maximum horizontal distance of the concrete is 6m. Since the height of the ring frame beam is greater than 1.3m, the feed openings 11 and the exhaust holes 10 in the ring frame beam are all poured and filled at the end of the final pouring.

[0212] According to the regulation of various parameters in the aforementioned anti-cracking and anti-seepage construction method of the present invention, it can be seen that all indicators in Table 9 meet the requirements. After the side wall of the working pit is cast according to the technical solution provided by the present invention, no problems such as penetrating shrinkage cracks, looseness and leakage occur.

[0213] Table 9 Key parameters for temperature monitoring of self-compacting and high crack resistance concrete

[0214] Mold temperature Maximum temperature rise Temperature difference between inside and outside Cooling rate 27.6℃ 28.6℃ 10℃ 1.6℃ / d

[0215] Although the present invention has been shown and described with reference to specific embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made herein without departing from the spirit and scope of the invention as defined by the claims and their equivalents. The crack resistance-related control indicators such as the mold entry temperature and the maximum temperature rise value proposed in the embodiments of the present invention can meet the performance requirements based on a cracking risk coefficient ≤ 0.7 and a non-cracking guarantee rate ≥ 95%. In the actual construction process, after the mold entry temperature and the maximum temperature rise value exceed the range defined by the present invention, the cracking risk coefficient may exceed 0.7, but when it does not exceed 1.0, the concrete may still not crack. Although this will result in a reduction in the non-cracking guarantee rate, the technical effect of no cracking can still be achieved, and the purpose of no cracking and no leakage can also be achieved.

[0216] In summary, the concrete anti-cracking and anti-seepage construction method for the side wall structure of the working shaft of an ultra-large diameter shield tunnel provided by the present invention has improvements and innovations in multiple construction processes and key indicators from the aspects of the contact mode of the retaining structure, the opening of the feed port 11 and the exhaust hole 10 on the ring frame beam, the roughening treatment of the bottom surface of the ring frame beam, the concrete pouring rate and the temperature entering the mold, the maximum temperature rise value of the concrete center, the concrete liquid level in the feed port 11 and the exhaust hole 10 being higher than the concrete liquid level in the side wall of the working shaft, so that the concrete chamber of the side wall structure of the working shaft is filled, which can effectively reduce the difficulty of concrete construction of the side wall structure of the working shaft of an ultra-large diameter shield tunnel, inhibit the occurrence of through shrinkage cracks in the concrete, achieve dense filling, and solve the problems of cracking and leakage.

[0217] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for anti-cracking and anti-seepage construction of the side wall of a working shaft of an ultra-large diameter shield tunnel, characterized in that: The steps include: Pre-treat the maintenance structure, ring frame beam and side wall outer formwork of the working pit side wall to be poured; The method for pre-treating the maintenance structure, ring frame beam and side wall outer formwork of the working pit side wall to be poured includes the following steps: A protective material is provided on the surface of the maintenance structure adjacent to the inner side surface of the side wall of the working pit to prevent direct contact between the maintenance structure and the inner side surface of the side wall of the working pit; A plurality of feed openings and a plurality of exhaust holes are provided on the ring frame beam at the top of the side wall of the working pit, and the lower surface of the ring frame beam is roughened; A number of exhaust holes are opened on the outer formwork of the working pit side wall within a certain distance from the adjacent top ring frame beam; Based on the average daily temperature during construction and the length of the single-side wall of the working pit, the temperature of the self-compacting, high-crack-resistant concrete poured into the side wall of the working pit is controlled; The self-compacting, high crack resistance concrete performance must meet the following conditions: The strength grade shall not exceed C45, the mold slump expansion shall be 600-700mm, T500 shall not exceed 6s, the inverted slump time shall not exceed 6s, the 7d adiabatic temperature rise shall not exceed 47°C, the ratio of the 1d adiabatic temperature rise value to the 7d adiabatic temperature rise value shall not exceed 50%, the 7d autogenous volume deformation shall not be less than 250με, the 28d autogenous volume deformation shall not be less than 220με, and the 56d autogenous volume deformation shall not be less than 200με; According to the different pouring locations of the working pit side wall, the pouring rate of the self-compacting, highly crack-resistant concrete is adjusted accordingly, and the maximum temperature rise value of the concrete center in the working pit side wall is controlled according to the length of the single side wall of the working pit; After the side wall of the working pit is poured, a certain amount of the self-compacting, highly crack-resistant concrete is continued to be poured through the discharge port, so that the concrete liquid level in the discharge port and the exhaust hole is higher than the concrete liquid level in the side wall of the working pit.

2. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 1 is characterized in that: The self-compacting, highly crack-resistant concrete comprises the following raw materials and weight fractions: 180-260 parts by mass of cement; 100-150 parts by mass of fly ash; 0 to 50 parts by mass of slag powder; 830-950 parts by mass of fine aggregate; 830-950 parts by mass of coarse aggregate; 36 to 50 parts by mass of an anti-cracking agent; 40-50 parts by mass of a rheology-modifying material; 4 to 6 parts by mass of water reducer; and 150 to 180 parts by mass of mixing water.

3. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 2 is characterized in that: The protective material includes spraying waterproof coating, or paving cloth-like woven fabric, or paving polymer waterproof coiled material.

4. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 1 is characterized in that: The control of the mold temperature comprises the following steps: Adjust the mold entry temperature of the self-compacting, high crack resistance concrete described in the working pit side wall according to the average daily temperature during construction and the length of the single side wall of the working pit: When the length of a single side wall is ≤30m, the mold entry temperature should be ≤ the average daily temperature and not greater than 28℃; When the length of a single side wall is greater than 30m, the temperature entering the mold shall be ≤ the average daily temperature and not greater than 25℃.

5. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 4 is characterized in that: The method for adjusting and controlling the pouring rate of the concrete includes: Control the pouring height rate of the lower wall of the working pit side wall to no more than 0.4m / h. When it is 30 to 50cm away from the waterstop at the top of the ring frame beam, let it stand for 1 to 3h, and then continue pouring at a pouring height rate of no more than 0.2m / h. Control the maximum horizontal flow distance of concrete to no more than 6m.

6. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 5 is characterized in that: The maximum temperature rise of the concrete center in the side wall of the working pit is regulated and controlled including: When the length of the single side wall of the working pit is not more than 30m, the maximum temperature rise of the concrete center shall be controlled not to exceed 35℃; When the length of a single side wall of the working pit is greater than 30m, the maximum temperature rise of the concrete center shall be controlled not to exceed 32°C.

7. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 6 is characterized in that: The control of the maximum temperature rise in the center of the concrete also includes burying several cooling water pipes in the side walls.

8. The method for anti-cracking and anti-seepage construction of side walls of a working shaft of an ultra-large diameter shield tunnel according to any one of claims 1 to 7, characterized in that: The pouring process of the working pit side wall also includes controlling the maximum cooling rate of the geometric center point of the working pit side wall to no more than 3℃ / d and the temperature difference between the inside and outside of the concrete to no more than 15℃.

9. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 1, characterized in that: The discharge port is arranged on the ring frame beam at the top of the side wall of the working pit, and the discharge port is opened between the central axis of the waterstop and the outer end of the waterstop along the extension direction of the waterstop.

10. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 9, characterized in that: The distance between adjacent feeding openings is no more than 2m.

11. The method for anti-cracking and anti-seepage construction of side walls of a working shaft of an ultra-large diameter shield tunnel according to claim 9 or 10, characterized in that: At least two rows of exhaust holes are provided on the waterstop of the ring frame beam along the extending direction of the waterstop.

12. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 11, characterized in that: The diameter of the exhaust holes is not less than 10 cm, the horizontal spacing between adjacent exhaust holes along the length direction of the ring frame beam is not more than 2 m, and the horizontal spacing between two adjacent rows of exhaust holes along the thickness direction of the ring frame beam is not more than 0.5 m.

13. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 12, characterized in that: The feed opening is located in the distribution direction of one row of exhaust holes in the at least two rows of exhaust holes and is alternately spaced with the exhaust holes.

14. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 13, characterized in that: The roughening treatment of the lower surface of the ring frame beam has a structural depth of 0.5 to 1.5 cm, and the roughening depth does not exceed 3 cm.

15. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 14, characterized in that: Several exhaust holes are set on the outer formwork of the working pit side wall within a distance of 0 to 10 cm close to the adjacent top ring frame beam.

16. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 15, characterized in that: The anti-cracking agent in the concrete component is HME-V concrete high-efficiency anti-cracking agent.

17. The method for anti-cracking and anti-seepage construction of the side wall of the working shaft of an ultra-large diameter shield tunnel according to claim 16, characterized in that: The water reducing agent in the concrete component is SBT-SCC self-compacting concrete admixture.

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