Active and passive integrated repair mortar for leaking tunnel lining and its construction process

Abstract

The present invention belongs to the technical field of tunnel lining repair, and specifically relates to an active and passive integrated repair mortar for leaking tunnel lining and a construction process. The active and passive integrated repair mortar for leaking tunnel lining of the present invention comprises a microbial slurry, a cementing solution and a self-repairing capsule; the components of the microbial slurry include urease bacteria and nutrients; the components of the cementing solution include urea and a first calcium salt; the self-repairing capsule is a core-shell structure, having an inner core and an outer shell, the components of the inner core include polyethylene glycol, urease bacteria spores and an activator, the components of the outer shell include epoxy resin and sodium alginate; the components of the activator include yeast extract, urea, a second nitrogen source and a second calcium salt. The construction process of the active and passive integrated repair mortar for leaking tunnel lining of the present invention is simple and easy, and can effectively reduce the leakage of cracks in tunnel lining.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel lining repair, and in particular relates to an active and passive integrated repair mortar for leaking tunnel lining and a construction process. Background Art

[0002] As an important transportation infrastructure, the safety and stability of tunnels are crucial to the reliable operation of transportation systems. During the construction and use of tunnels, they are often affected by various internal and external factors, such as geological conditions, construction technology, environmental changes, and long-term mechanical loads. These factors often lead to cracks in the tunnel lining structure. The presence of cracks will not only reduce the overall structural stability of the tunnel, but may also cause water leakage, causing further damage to the structure.

[0003] There are many causes of tunnel lining cracks, including: (1) construction quality problems, such as uneven concrete pouring and improper maintenance; (2) geological factors, including the influence of natural factors such as stratum movement and rock weathering; (3) external environmental influences, such as earthquakes and hydrological changes; (4) material fatigue caused by long-term bearing pressure. As the tunnel ages, these cracks may gradually expand and cause more serious safety problems.

[0004] Traditional methods for repairing cracks in tunnel linings usually include crack grouting, reinforcing linings, replacing damaged sections, etc. Among them, crack grouting is a commonly used repair technology that fills the crack space by injecting materials such as cement slurry or resin into the cracks to restore the continuity and waterproofness of the structure. However, this method has several significant disadvantages: (1) Traditional grouting methods generally only repair single cracks, and it is difficult to repair all cracks in a section at the same time, which is time-consuming, labor-intensive, and inefficient. (2) The repair effect is limited by material properties and construction technology and cannot adapt to the dynamic changes of cracks. Once new cracks are formed or old cracks expand, they need to be repaired again. (3) The volume stability and durability of the grouting material after hardening are limited and may fail over time.

[0005] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0006] The purpose of the present invention is to provide an active and passive integrated repair mortar for leaking tunnel lining and a construction process, so as to solve or improve the problem in the prior art that the repair effect of crack grouting on tunnel lining needs to be improved and the repair efficiency is low.

[0007] In order to achieve the above-mentioned objectives, the present invention provides the following technical solutions: an active and passive integrated repair mortar for leaking tunnel lining, comprising a microbial slurry, a cementing solution and a self-repairing capsule; the components of the microbial slurry include urease bacteria and nutrients; the components of the cementing solution include urea and a first calcium salt; the self-repairing capsule is a core-shell structure, having an inner core and an outer shell, the components of the inner core include polyethylene glycol, urease bacteria spores and an stimulant, and the components of the outer shell include epoxy resin and sodium alginate; the components of the stimulant include yeast extract, urea, a second nitrogen source and a second calcium salt; the first calcium salt and / or the second calcium salt are soluble calcium salts, and the first calcium salt and the second calcium salt are the same or different.

[0008] Preferably, the nutrients in the microbial slurry are yeast extract and a first nitrogen source; and in the cementing solution, the concentrations of urea and the first calcium salt are 0.1-5 mol / L, respectively.

[0009] Preferably, the self-repairing capsule is prepared by a method comprising the following steps: A1. heating the polyethylene glycol, uniformly mixing the urease bacteria spores, the stimulant and the polyethylene glycol, cooling and solidifying to obtain a solidified colloid; A2. cutting the solidified colloid to obtain spherical particles; A3. coating the surface of the spherical particles with an epoxy resin layer by rotating and shaking; A4. placing the spherical particles obtained by the treatment in step A3 in sodium alginate powder, rotating and shaking to make the sodium alginate adhere, thereby obtaining the self-repairing capsule.

[0010] Preferably, the temperature of the polyethylene glycol heating is 60-80°C; the mass ratio of the sum of the amounts of the stimulant and the urease bacteria spores to the polyethylene glycol is 0.01:1-1:1; the mass ratio of the yeast extract, urea and the second calcium salt in the stimulant is (0.5-1.5):(0.5-1.5):(0.5-1.5); the cooling and curing is carried out in an environment of 4°C, and the cooling and curing time is 4-12 h.

[0011] Preferably, the particle size of the spherical particles obtained by the treatment in step A2 is 0.1-2.5 mm; in step A3, the thickness of the epoxy resin layer is 0.1-5 mm.

[0012] Preferably, the volume ratio of the microbial slurry to the cementing solution is 1:1-1:5; and the volume of the self-repairing capsule is 1%-5% of the total volume of the microbial slurry and the cementing solution.

[0013] The present invention also provides a construction process for active and passive integrated repair of a leaking tunnel lining, which adopts the following technical scheme: A construction process for active and passive integrated repair of a leaking tunnel lining, comprising the following steps: (1) using a grouting machine to inject a mixed solution of sodium alginate and calcium chloride into the space between a target repair area of ​​the tunnel lining and the surrounding rock through a grouting pipe reserved on the tunnel lining, so as to temporarily repair the target repair area of ​​the tunnel lining; (2) mixing the microbial slurry with the cementing solution, adding the self-repairing capsule, and obtaining the active and passive integrated repair mortar for the leaking tunnel lining; (3) injecting the active and passive integrated repair mortar for the leaking tunnel lining as described above into the space between the target repair area of ​​the tunnel lining and the surrounding rock through a grouting pipe reserved on the tunnel lining by using a grouting machine, so that the active and passive integrated repair mortar for the leaking tunnel lining enters the cracks in the target repair area under the action of gravity seepage.

[0014] Preferably, after step (3), the method further includes injecting cement mortar into the space between the tunnel lining and the surrounding rock through the grouting pipe.

[0015] Preferably, in step (3), the grouting speed of the grouting machine is 10-100 mL / min.

[0016] Beneficial effects:

[0017] (1) The active and passive integrated repair mortar for leaky tunnel lining of the present invention has self-repairing ability, can cope with the dynamic changes of cracks, reduce maintenance frequency, and improve the long-term effectiveness and reliability of repair. In addition, the construction process of the active and passive integrated repair mortar for leaky tunnel lining of the present invention is simple and easy (after the active and passive integrated repair mortar for leaky tunnel lining of the present invention is injected through the grouting pipe, under the action of gravity seepage, the active and passive integrated repair mortar for leaky tunnel lining of the present invention can flow into the cracks on the seepage flow path to repair the cracks), and is cost-effective (it can repair multiple cracks in the target repair area at the same time, and can not only repair existing cracks, but also continue to monitor and respond to the formation of new cracks after the material solidifies, realize dynamic repair, and significantly improve the safety and toughness of the tunnel lining), and can meet the economic and technical needs of modern tunnel engineering (it has high efficiency in crack repair and helps to reduce maintenance costs). The active and passive integrated repair mortar for leaky tunnel lining of the present invention can effectively reduce the leakage of cracks.

[0018] (2) The present invention does not directly grout the tunnel lining, but injects the active and passive integrated mortar of the leaking tunnel lining as a reinforcing mortar into the junction of the tunnel lining and the surrounding rock, and then enters the target repair area through gravity seepage, which does not generate additional process, is convenient for construction, and saves costs. These advantages demonstrate the significant technical and economic improvements of the present invention, which is of great significance to the improvement of existing tunnel lining crack repair technology.

[0019] (3) The active and passive integrated repair mortar for leaky tunnel lining of the present invention can work effectively under various environmental conditions, including different humidity and temperature conditions. The biological activity of microorganisms enables the mortar to maintain its repair ability in a wider range of environments, increasing the applicability and practicality of the material.

[0020] (4) By repairing cracks by combining temporary and long-term repairs, and passive and active crack repair methods, the present invention significantly improves the structural integrity and durability of the tunnel lining. This continuous self-repairing ability can effectively delay the aging and wear process of the lining, thereby extending the service life of the tunnel.

[0021] (5) Since the active and passive integrated repair mortar for the leaking tunnel lining of the present invention has a self-repairing function, it can reduce the dependence on professional maintenance teams. Compared with traditional repair methods, it can greatly reduce the need for regular inspections and repairs, thereby reducing long-term maintenance costs and labor requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0023] Figure 1 A schematic diagram of the construction process of the active and passive integrated repair mortar for the leaking tunnel lining provided by an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of the structure of a self-repairing capsule provided by an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of a passive repair process of an active and passive integrated repair mortar for a leaking tunnel lining provided by an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of a process for actively repairing cracks in a leaky tunnel lining after re-cracking provided by an embodiment of the present invention;

[0027] Figure 5 Schematic diagram of the experimental setup;

[0028] Figure 6 This is a comparison chart of the permeability coefficients measured in simulation experiments 1, 2, and 3;

[0029] Figure 7 A comparison diagram of permeability coefficients measured when passive and active repairs are performed on the leaking tunnel lining active and passive integrated repair sand provided in one embodiment of the present invention;

[0030] Figure 8The test results of the Brazilian splitting test of the samples obtained from simulation experiments 1, 2 and 3 are shown in FIG.

[0031] Reference numerals:

[0032] 1- tunnel lining; 11- crack; 12- lining joint; 13- grouting pipe; 14- crack seepage water;

[0033] 2-leakage tunnel lining active and passive integrated repair mortar; 21-self-repairing capsule; 211-active repair sodium alginate; 2111-active repair calcium alginate hydrogel; 212-urease bacteria spores; 2121-active repair calcium carbonate precipitation; 213-polyethylene glycol; 214-epoxy resin; 215-activator; 22-urease bacteria; 221-passive repair calcium carbonate precipitation;

[0034] 31-passive repair of sodium alginate; 311-passive repair of calcium alginate hydrogel;

[0035] 41-PVC mold; 411-grouting inlet; 42-sand column; 43-concrete; 431-concrete crack; 44-injection pipe; 45-peristaltic pump;

[0036] 5-surrounding rock; 51-surrounding rock lining void area; 6-external load. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0038] The present invention will be described in detail below in conjunction with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0039] In the prior art, crack repair of tunnel lining is usually carried out by injecting materials such as cement slurry or resin into the crack. However, when using materials such as cement slurry or resin to repair cracks in tunnel lining, usually only a single crack (crack that meets the repair conditions) is repaired, and it is difficult to repair multiple cracks in the same area, and the efficiency of crack repair is low (when grouting cement slurry or resin into a single crack in the prior art, it cannot be done through the grouting holes reserved in the tunnel lining). Moreover, the existing crack grouting technology is difficult to repair tiny and difficult-to-find cracks, so that tiny cracks will continue to develop and expand, affecting the safety of the tunnel lining. In addition, the grouting materials used in the prior art cannot adapt to the dynamic changes of cracks. Once new cracks are formed or old cracks expand, they need to be repaired again.

[0040] Aiming at the problem that the existing crack grouting has low repair efficiency for cracks in tunnel lining or cannot adapt to the dynamic changes of cracks, the present invention provides an active and passive integrated repair mortar for leaking tunnel lining.

[0041] The active and passive integrated repair mortar for leaking tunnel lining according to the embodiment of the present invention comprises a microbial slurry, a cementing solution and a self-repairing capsule; the components of the microbial slurry include urease bacteria and nutrients; the components of the cementing solution include urea and a first calcium salt; the self-repairing capsule 21 is a core-shell structure (refer to Figure 2 ), having an inner core and an outer shell, the components of the inner core include polyethylene glycol 213, urease bacteria spores 212 and an activator 215, and the components of the outer shell include epoxy resin 214 and sodium alginate (actively repairing sodium alginate 211); the components of the activator 215 include yeast extract, urea, a second nitrogen source (providing a nitrogen source for urease bacteria after the urease bacteria spores are revived) and a second calcium salt; the first calcium salt and / or the second calcium salt are soluble calcium salts, and the first calcium salt and the second calcium salt are the same or different (preferably, the first calcium salt and the second calcium salt are each independently selected from at least one of calcium chloride, calcium acetate and calcium lactate).

[0042] Preferably, the OD600 value of the microbial slurry is 0.1-1.0 (used to characterize the concentration of urease bacteria in the microbial slurry; for example, the OD600 value is 0.1, 0.3, 0.5, 0.7, 0.9 or 1.0), and the urease activity of the microbial slurry is 0.1-30 mmol / L / min (for example, 0.1 mmol / L / min, 0.5 mmol / L / min, 1 mmol / L / min, 5 mmol / L / min, 10 mmol / L / min, 15 mmol / L / min, 20 mmol / L / min, 25 mmol / L / min or 30 mmol / L / min).

[0043] In the active and passive integrated repair mortar for the leaking tunnel lining of the embodiment of the present invention, urease bacteria and a cementing solution are used in combination (the microbial slurry and the cementing solution are stored separately before use; the urease bacteria and nutrients in the microbial slurry are also stored separately before use). The urease bacteria 22 can hydrolyze urea to generate carbonate ions and calcium ions to react to generate calcium carbonate precipitates (passive repair calcium carbonate precipitates 221) to seal the cracks in the tunnel lining; the self-repairing capsules 21 make it possible for, after the cracks are sealed, if the repaired area of ​​the tunnel lining cracks again under the action of the external load 6, the self-repairing capsules 21 will rupture under the action of the external load 6, releasing sodium alginate (active repair sodium alginate 211), urease bacteria spores 212 and stimulators 215, then When rainwater or groundwater flows through the fissure 11 generated by the cracking again, sodium alginate (actively repairing sodium alginate 211), urease bacteria spores 212 and stimulator 215 are brought into the fissure 11 of the tunnel lining 1, and the calcium ions generated by the sodium alginate (actively repairing sodium alginate 211) and the second calcium source in the stimulator 215 undergo a complex reaction to generate calcium alginate hydrogel (actively repairing calcium alginate hydrogel 2111), thereby achieving temporary repair of the leaking tunnel lining; in addition, the urease bacteria spores 212 are revived under the action of the stimulator 215 and water, and the urea is hydrolyzed to generate carbonate ions, and the carbonate ions react with the calcium ions in the calcium salt to generate calcium carbonate precipitates (actively repairing calcium carbonate precipitates 2121), thereby achieving long-term repair of the cracks in the tunnel lining.

[0044] Passive repair process (refer to Figure 3 ) includes: after the active and passive integrated repair mortar 2 of the leaking tunnel lining of the present invention is grouted between the tunnel lining 1 and the surrounding rock 5 through the grouting pipe 13, it can enter the target repair area under the action of gravity seepage; wherein, the self-repairing capsule 21 will migrate with the flow of slurry in the hollow type and hollow type cracks of the tunnel lining, and can enter multiple cracks 11 in the target repair area; during the seepage process, if it encounters a rough surface, protrusion or narrow channel and stops, it will play a role in filling the crack space and assisting in plugging; the urease bacteria 22 in the microbial slurry will hydrolyze the urea in the cementing solution to generate carbonate, and the carbonate combines with calcium ions (derived from calcium chloride in the cementing solution) to generate calcium carbonate precipitates (passive repair calcium carbonate precipitates 221) to plug the cracks 11 and achieve long-term repair of the cracks 11. Active repair process (refer to Figure 4): The self-repairing capsule 21 can also play an active repair role in the future. After the crack 11 appears again in the tunnel lining 1, the self-repairing capsule 21 ruptures, releasing sodium alginate (actively repairing sodium alginate 211), urease bacteria spores 212 and stimulant 215. Under the action of rainwater or underground seepage, the sodium alginate (actively repairing sodium alginate 211) and the second calcium salt in the stimulant 215 generate calcium alginate hydrogel (actively repairing calcium alginate hydrogel 2111) to temporarily repair the crack 11; after the urease bacteria spores 212 are revived, urea is hydrolyzed to generate carbonate ions, which react with the second calcium salt to generate calcium carbonate precipitates (actively repairing calcium carbonate precipitates 2121) to facilitate the long-term repair of the crack 11.

[0045] The active and passive integrated repair mortar for leaking tunnel lining of the present invention can be grouted between the target repair area and the surrounding rock 5 through the grouting pipe 13 reserved in the tunnel lining 1 (refer to Figure 1 ; The tunnel lining 1 can be spliced ​​and has a lining splicing seam 12; during the use of the tunnel lining 1, a surrounding rock lining void area 51 may be formed between the surrounding rock 5 and the tunnel lining 1), under the action of gravity seepage (such as Figure 1 As shown, in the case of leakage in the tunnel lining 1, there will be fissure seepage water 14 at the fissure 11; therefore, the active and passive integrated repair mortar 2 for the leaking tunnel lining of the present invention can also enter the fissure 11 under the action of gravity seepage), that is, it can enter multiple fissures 11 (including tiny, difficult-to-find cracks) in the target repair area, thereby achieving efficient repair of the target repair area of ​​the tunnel lining 1; and the self-repairing capsule 21 helps to achieve active repair of the fissure 11, and helps to reduce or prevent the formation of new cracks or the expansion of old cracks; the active and passive integrated repair mortar 2 for the leaking tunnel lining of the present invention can effectively reduce or avoid leakage of the tunnel lining 1.

[0046] Preferably, the urease-producing bacteria is obtained by culturing and screening in an alkaline medium and has good tolerance to the high alkaline environment of concrete.

[0047] In a preferred embodiment of the active and passive integrated repair mortar for leaking tunnel lining of the present invention, the nutrients in the microbial slurry are yeast extract and the first nitrogen source; in the cementing solution, the concentrations of urea and the first calcium salt are 0.1-5 mol / L (for example, 0.1 mol / L, 0.5 mol / L, 1 mol / L, 2 mol / L, 3 mol / L, 4 mol / L or 5 mol / L), respectively. The first nitrogen source and the second nitrogen source may be the same (for example, ammonium sulfate may be used for both the first nitrogen source and the second nitrogen source) or different (different substances may be used for the first nitrogen source and the second nitrogen source).

[0048] In the preferred embodiment of the active and passive integrated repair mortar for leaking tunnel lining of the present invention, the self-repairing capsule is prepared by a method comprising the following steps: A1. heating polyethylene glycol, mixing urease bacteria spores, stimulant and polyethylene glycol evenly, cooling and solidifying to obtain a solidified colloid; A2. cutting the solidified colloid to obtain spherical particles; A3. coating the surface of the spherical particles with an epoxy resin layer by means of rotational oscillation (which can be performed in a rotational oscillator); A4. placing the spherical particles obtained by the treatment in step A3 in sodium alginate powder, rotating and oscillating the sodium alginate so that the sodium alginate is wrapped in the epoxy resin layer, and then horizontally vibrating to remove the attached sodium alginate powder. Among them, polyethylene glycol can play a role in protecting urease bacteria spores.

[0049] In a preferred embodiment of the active and passive integrated repair mortar for leaking tunnel lining of the present invention, the temperature at which the polyethylene glycol is heated is 60-80°C (for example, 60°C, 65°C, 70°C, 75°C or 80°C). ℃); the mass ratio of the sum of the amounts of the stimulant and the urease bacteria spores to the polyethylene glycol is 0.01:1-1:1 (for example, 0.01:1, 0.05:1, 0.1:1, 0.3:1, 0.5:1, 0.8:1 or 1:1); the mass ratio of the yeast extract, urea and calcium salt in the stimulant is (0.5-1.5):(0.5-1.5):(0.5-1.5) (for example, 0.5:1.0:1.5, 0.5:1.5:1.0, 0.5:1.5:0.5, 0.5:1.0:1.0, 1.0:1.0:1.5, 1.0:1.0:1.0, 1.5:1.0:0.5, 1.5:1.0:1.0, etc.); the cooling and curing is carried out in an environment of 4℃, and the cooling and curing time is 4-12 h (for example, 4 h, 6 h, 8 h, 10 h or 12 h).

[0050] Preferably, the mass ratio of the second nitrogen source to the yeast extract in the stimulator is (12-18):20 (for example, 12:20, 14:20, 16:20 or 18:20), and the mass ratio of urease bacteria spores to the stimulator is (0.5-1.5):10 (for example, 0.5:10, 1:10 or 1.5:10).

[0051] In a preferred embodiment of the active and passive integrated repair mortar for leaking tunnel lining of the present invention, the particle size of the spherical particles obtained by the treatment in step A2 is 0.1-2.5 mm (for example, 0.1 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm or 2.5 mm); in step A3, the thickness of the epoxy resin layer is 0.1-5 mm (for example, 0.1 mm, 0.5 mm, 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm or 5 mm).

[0052] In a preferred embodiment of the active and passive integrated repair mortar for leaking tunnel lining of the present invention, the volume ratio of the microbial slurry to the cementing solution is 1:1-1:5 (for example, 1:1, 1:2, 1:3, 1:4 or 1:5); the volume of the self-repairing capsule is 1%-5% (for example, 1%, 2%, 3%, 4% or 5%) of the total volume of the microbial slurry and the cementing solution.

[0053] The present invention also proposes a construction process for active and passive integrated repair of a leaking tunnel lining. The construction process for active and passive integrated repair of a leaking tunnel lining according to an embodiment of the present invention comprises the following steps: (1) using a grouting machine to inject a mixed solution of sodium alginate and calcium chloride into the space between a target repair area of ​​the tunnel lining 1 and the surrounding rock 5 through a grouting pipe 13 reserved on the tunnel lining, so as to temporarily repair the target repair area of ​​the tunnel lining; (2) mixing the microbial slurry with the cementing solution, adding self-repairing capsules 21, and obtaining an active and passive integrated repair mortar 2 for the leaking tunnel lining; (3) injecting the active and passive integrated repair mortar 2 for the leaking tunnel lining as described above into the space between the target repair area of ​​the tunnel lining and the surrounding rock through a grouting pipe 13 reserved on the tunnel lining by a grouting machine, so that the active and passive integrated repair mortar for the leaking tunnel lining enters the cracks 11 in the target repair area under the action of gravity seepage. Wherein, in the mixed solution of sodium alginate and calcium chloride (ready to use after mixing) in step (1), the concentrations of sodium alginate and calcium chloride are 0.1-10 mol / L (for example, 0.1 mol / L, 0.5 mol / L, 1 mol / L, 3 mol / L, 5 mol / L, 7 mol / L, 9 mol / L or 10 mol / L).

[0054] In the construction process of the active and passive integrated repair of the leaking tunnel lining of the present invention, the sodium alginate (passive repair sodium alginate 31) and calcium chloride solution grouting in step (1) will enter the target repair area under the action of seepage, and react to form calcium alginate hydrogel (passive repair calcium alginate hydrogel 311) in the cracks 11 in the target repair area, thereby achieving temporary repair of the cracks 11 in the target repair area; after grouting the active and passive integrated repair mortar 2 for the leaking tunnel lining in step (3), the urease bacteria 22 in the microbial slurry decomposes urea into carbonate ions, which form calcium carbonate precipitates (passive repair calcium carbonate precipitates 221) after contacting with calcium ions, thereby achieving long-term repair of the cracks 11 in the target repair area, thereby completing the passive repair process (refer to Figure 3 ); afterwards, if cracks are generated again in the target repair area under the action of the external load 6, the self-repairing capsule 21 ruptures, realizing active repair of the newly generated cracks (refer to Figure 4): The self-repairing capsule 21 ruptures to release sodium alginate (actively repairing sodium alginate 211), urease bacterial spores 212 and stimulant 215. The sodium alginate (actively repairing sodium alginate 211) reacts with the calcium salt in the stimulant to form calcium alginate hydrogel (actively repairing calcium alginate hydrogel 2111) to temporarily repair the cracks. After the urease bacterial spores 212 are activated, the urea in the stimulant is hydrolyzed to form carbonate, and the carbonate reacts with the calcium ions in the calcium salt to form calcium carbonate precipitate (actively repairing calcium carbonate precipitate 2121) to achieve long-term repair of the cracks.

[0055] In a preferred embodiment of the construction process for active and passive integrated repair of leaking tunnel lining of the present invention, it also includes the step of injecting cement mortar between the tunnel lining 1 and the surrounding rock 5 through a grouting pipe. By injecting cement mortar, the repair of the surrounding rock lining void area 51 can be achieved.

[0056] In a preferred embodiment of the construction process for active and passive integrated repair of leaking tunnel lining of the present invention, in step (3), the grouting speed of the grouting machine is 10-100 mL / min (for example, 10 mL / min, 30 mL / min, 50 mL / min, 70 mL / min, 90 mL / min or 100 mL / min).

[0057] The active and passive integrated repair mortar for leaking tunnel lining and the construction process of the present invention are described in detail below through specific embodiments.

[0058] In the following embodiments:

[0059] The strains and reagents used can be purchased commercially; among them, yeast extract, urea, calcium chloride, sodium alginate, polyethylene glycol and epoxy resin were purchased from Sinopharm Chemical Reagent Co., Ltd.

[0060] Example 1

[0061] The active and passive integrated repair mortar for the leaking tunnel lining of this embodiment includes:

[0062] Microbial slurry, including urease bacteria and nutrients, the OD600 of urease bacteria is 1.0, and the nutrients include yeast extract (concentration is 20 g / L) and ammonium sulfate (concentration is 15.75 g / L); cementing solution, including urea and calcium chloride (the concentration of urea and calcium chloride are both 1 mol / L);

[0063] The self-repairing capsule is prepared by a method comprising the following steps: A1. heating polyethylene glycol to 60° C., mixing urease bacteria spores, an activator and polyethylene glycol (the mass ratio of the sum of the amounts of urease bacteria spores and the activator to polyethylene glycol is 1:1, the mass ratio of yeast extract, urea and calcium chloride in the activator is 1:1:1, the mass ratio of ammonium sulfate to yeast extract in the activator is 15.75:20, and the mass ratio of urease bacteria spores to the activator is 1:10) evenly, cooling and curing in a refrigerator at 4° C. for 24 h to obtain a solidified colloid; A2. cutting the solidified colloid to obtain spherical particles (with a particle size of 0.5 mm); A3. coating an epoxy resin layer (the thickness of the epoxy resin layer is 0.1 mm) on the surface of the spherical particles by rotational oscillation (which can be performed in a rotational oscillator); mm); A4. Place the spherical particles obtained by the treatment in step A3 in sodium alginate powder, rotate and shake to wrap the sodium alginate in the epoxy resin layer, and then shake horizontally to remove the attached sodium alginate powder, so as to obtain a self-repairing capsule.

[0064] Among them, the volume ratio of microbial slurry to cementing solution is 1:1, and the volume ratio of self-healing capsules to the sum of microbial slurry and cementing solution is 0.001:1; the microbial slurry, cementing solution and self-healing capsules are stored separately and mixed before use (ready-to-use).

[0065] The construction process for active and passive integrated repair of leaking tunnel lining in this embodiment includes the following steps:

[0066] (1) A grouting machine is used to inject a mixed solution of sodium alginate and calcium chloride (the concentrations of sodium alginate and calcium chloride are both 1 mol / L) between the target repair area of ​​the tunnel lining and the surrounding rock through the grouting pipe reserved on the tunnel lining to temporarily repair the target repair area of ​​the tunnel lining;

[0067] (2) mixing the above-mentioned microbial slurry with the cementing solution, adding self-repairing capsules, and obtaining the active and passive integrated repair mortar for the leaking tunnel lining of this embodiment;

[0068] (3) The active and passive integrated repair mortar for the leaking tunnel lining as described above (as a reinforcing mortar) is injected into the target repair area of ​​the tunnel lining and the surrounding rock through a grouting pipe reserved on the tunnel lining at a grouting flow rate of 50 mL / min using a grouting machine, so that the active and passive integrated repair mortar for the leaking tunnel lining of this embodiment enters the cracks in the target repair area of ​​the tunnel lining under the action of gravity seepage.

[0069] Example 2

[0070] The active and passive integrated repair mortar for the leaking tunnel lining of this embodiment is the same as that of Embodiment 1.

[0071] The construction process of active and passive integrated repair of leaking tunnel lining in this embodiment is different from that in Embodiment 1 only in that:

[0072] After step (3), the method further includes the following steps: injecting cement mortar (the volume ratio of cement mortar to active and passive integrated repair mortar for leaking tunnel lining is 1:1; the components of cement mortar are: 60% limestone, 15% clay, 3% alumina, 2% silicate, 0.5% iron oxide and water, with water making up to 100%) through a grouting pipe reserved on the tunnel lining to repair the void area of ​​the surrounding rock lining.

[0073] Comparative Example 1

[0074] The difference between this comparative example and Example 1 is that an equal volume of cement mortar (60% limestone, 15% clay, 3% alumina, 2% silicate, 0.5% iron material, and the balance water) is used instead of the active and passive integrated repair mortar for the leaking tunnel lining (i.e., in step (3), the cement mortar is injected into the target repair area of ​​the tunnel lining and the surrounding rock through the grouting holes reserved on the tunnel lining at a grouting flow rate of 50 mL / min using a grouting machine).

[0075] Experimental example

[0076] The repair effect of the active and passive integrated repair mortar for leaking tunnel lining of the present invention on leaking tunnel lining was verified through indoor experimental simulation.

[0077] Experimental method: Using Figure 5 The experimental device shown in the figure (wherein the upper sand column 42 is used to simulate the surrounding rock, the lower concrete 43 and its concrete cracks 431 are used to simulate the tunnel lining with cracks; in actual working conditions, when grouting is performed in the tunnel from the grouting port, the slurry will first pass through the surrounding rock and then reach the lining cracks) is used for a simulation experiment; during the experiment, a peristaltic pump 45 is first used to pump 50 mL of a mixed solution of sodium alginate and calcium chloride at a rate of 10 mL / min (in the mixed solution, the concentration of sodium alginate is 1 mol / L, and the concentration of calcium chloride is 1 mol / L); then, a peristaltic pump 45 is used to inject the experimental mortar at a rate of 2 mL / min (after the experimental mortar passes through the injection pipe 44, it flows out from the grouting inlet 411 above the sand column 42 and enters the PVC mold 41; the sand column 42 is formed by sand particles (particle size is 1-2 mm) accumulated in the PVC mold 41), and the data are recorded for 0-150 h. The change process of the permeability of the concrete sample containing cracks (obtained by the variable head method) is used as the experimental result of passive repair.

[0078] 1. Carry out the following simulation experiments respectively:

[0079] Simulation experiment 1: A simulation experiment was conducted using 50 mL of the active and passive integrated repair mortar for the leaking tunnel lining of Example 1 as the experimental mortar to simulate the construction process of Example 1;

[0080] Simulation experiment 2: First, 25 mL of the active and passive integrated repair mortar for the leaking tunnel lining of Example 1 was used as the experimental mortar for a simulation experiment, and then 25 mL of cement mortar was used as the experimental mortar for a simulation experiment to simulate the construction process of Example 2;

[0081] Simulation experiment 3: A simulation experiment was carried out using 50 mL of cement mortar as the experimental mortar to simulate the construction process of comparative example 1.

[0082] Experimental results: Figure 6 As shown, simulation experiment 1 can reduce the permeability coefficient of concrete samples containing cracks by 3-4 orders of magnitude, indicating that the active and passive integrated repair mortar for leaking tunnel lining and the corresponding construction process of Example 1 can effectively reduce the permeability coefficient of concrete containing cracks, and has good application prospects in the repair of leaking tunnel linings; the effect of reducing the permeability coefficient in simulation experiment 3 is significantly worse, which may be due to the large particle size and poor fluidity of the cement mortar, which is blocked in the upper sand column and cannot enter the concrete cracks in the lower part of the experimental device, indicating that the cement mortar commonly used in tunnel lining repair in the prior art is difficult to achieve effective repair of the leaking tunnel lining by grouting through the grouting holes reserved in the tunnel lining; simulation experiment 2 can better reduce the permeability of concrete containing cracks (the active and passive integrated repair mortar for leaking tunnel lining blocks small pores, and the cement mortar blocks large pores. The combination of the two has a better effect).

[0083] 2. A simulation experiment was carried out using 50 mL of the active and passive integrated repair mortar for the leaking tunnel lining of Example 1 as the experimental mortar. The change process of the permeability of the cracked concrete sample within 0-150 h was recorded as the experimental result of passive repair. After that, a load was applied to the cracked concrete sample (a load of 5 kN was applied along the crack direction by a universal testing machine) to make it crack again, and water was injected from the top of the sand column (the injection rate was 5 mol / min, and the injection time was 150 h). The change process of the permeability coefficient of the cracked concrete within 0-150 h was recorded again as the experimental result of active repair.

[0084] The experimental results are as follows Figure 7 shown by Figure 7It can be seen that both repair processes can reduce the permeability coefficient of cracked concrete by 3-4 orders of magnitude. This shows that when cracks appear in the tunnel lining again, the self-repairing capsules in the active and passive integrated repair mortar for leaky tunnel lining of the present invention can significantly reduce the permeability of the tunnel lining by generating calcium alginate gel when in contact with water and calcium carbonate precipitation generated after the urease bacteria spores are revived, which helps to slow down or prevent the further development of cracks and protect the tunnel lining.

[0085] 3. For the above-mentioned simulation experiments 1, 2 and 3, Brazilian splitting tests were carried out on the cracked concrete samples 50 h, 100 h and 150 h after the injection of the experimental mortar (Brazilian splitting tests were carried out using a universal testing machine at a speed of 1 mm / min), and the tensile strength recovery rate (strength after repair / initial strength) was measured.

[0086] The experimental results are as follows Figure 8 shown.

[0087] Depend on Figure 8 It can be seen that simulation experiment 2 (ie, the construction process of Example 2) can effectively improve the tensile strength of the cracked concrete samples.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A leaking tunnel lining active and passive integrated repair mortar, characterized in that: Includes microbial slurries, cementing solutions, and self-healing capsules; The components of the microbial slurry include urease bacteria and nutrients; the components of the cementing solution include urea and a first calcium salt; The self-repairing capsule is in a core-shell structure, comprising an inner core and an outer shell, wherein the components of the inner core include polyethylene glycol, urease bacteria spores and an activator, and the components of the outer shell include epoxy resin and sodium alginate; The components of the stimulant include yeast extract, urea, a second nitrogen source and a second calcium salt; The first calcium salt and / or the second calcium salt are soluble calcium salts, and the first calcium salt and the second calcium salt are the same or different; The self-repairing capsule is prepared by a method comprising the following steps: A1. Heating the polyethylene glycol, mixing the urease bacteria spores, the stimulant and the polyethylene glycol uniformly, cooling and solidifying to obtain a solidified colloid; A2. Cutting the solidified colloid to obtain spherical particles; A3. Coating an epoxy resin layer on the surface of the spherical particles by rotational oscillation; A4. Place the spherical particles obtained by the treatment in step A3 in sodium alginate powder, rotate and shake to make the sodium alginate adhere, and obtain the self-repairing capsule.

2. The active and passive integrated repair mortar for leaking tunnel lining according to claim 1, characterized in that: The nutrients in the microbial slurry are yeast extract and a first nitrogen source; In the cementing solution, the concentrations of urea and the first calcium salt are 0.1-5 mol / L respectively.

3. The active and passive integrated repair mortar for leaking tunnel lining according to claim 1, characterized in that: The temperature of the polyethylene glycol heating is 60-80°C; The mass ratio of the sum of the amounts of the stimulant and the urease bacteria spores to the polyethylene glycol is 0.01:1-1:1; The mass ratio of the yeast extract, urea and the second calcium salt in the stimulator is (0.5-1.5):(0.5-1.5):(0.5-1.5); The cooling and curing is carried out in a 4°C environment, and the cooling and curing time is 4-12 hours.

4. The active and passive integrated repair mortar for leaking tunnel lining according to claim 1, characterized in that: The particle size of the spherical particles obtained by the treatment in step A2 is 0.1-2.5 mm; In step A3, the thickness of the epoxy resin layer is 0.1-5 mm.

5. The active and passive integrated repair mortar for leaking tunnel lining according to claim 4, characterized in that: The volume ratio of the microbial slurry to the cementing solution is 1:1-1:5; The volume of the self-repairing capsule is 1%-5% of the total volume of the microbial slurry and the cementing solution.

6. A construction process for active and passive integrated repair of leaking tunnel lining, characterized in that: The steps include: (1) Use a grouting machine to inject a mixed solution of sodium alginate and calcium chloride into the space between the target repair area of ​​the tunnel lining and the surrounding rock through the grouting pipe reserved on the tunnel lining to temporarily repair the target repair area of ​​the tunnel lining; (2) mixing the microbial slurry with the cementing solution, adding the self-repairing capsules, and obtaining the active and passive integrated repair mortar for the leaking tunnel lining as claimed in any one of claims 1 to 5; (3) The active and passive integrated repair mortar for the leaking tunnel lining is injected into the gap between the target repair area of ​​the tunnel lining and the surrounding rock through a grouting pipe reserved on the tunnel lining by a grouting machine, so that the active and passive integrated repair mortar for the leaking tunnel lining enters the cracks in the target repair area under the action of gravity seepage.

7. The construction process for active and passive integrated repair of leaking tunnel lining according to claim 6, characterized in that: After step (3), the method further includes injecting cement mortar into the space between the tunnel lining and the surrounding rock through the grouting pipe.

8. The construction process for active and passive integrated repair of leaking tunnel lining according to claim 6, characterized in that: In step (3), the grouting speed of the grouting machine is 10-100 mL / min.

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