Method and structure for renovating cavity diseases behind existing railway tunnel lining

Abstract

The invention provides a method and a structure for renovating cavity diseases behind existing railway tunnel linings. The existing railway tunnel lining back cavity disease treatment method comprises the step of filling and reinforcing the low-elasticity light grouting material. The low-elasticity light grouting material is adopted to fill and reinforce the cavity after the tunnel lining, and the low-elasticity light grouting material has the excellent performance characteristics of quick setting, light weight, low-elasticity damping property, water resistance and the like, so that the filling can be completed in a short skylight time; the impact load of part of falling blocks of the surrounding rock can be absorbed or dispersed, the secondary load of the tunnel lining is greatly reduced, a certain waterproof effect is generated on leakage water of the surrounding rock, the back cavity damage of the tunnel lining treated through the method is remarkably improved, and the structural stability of the tunnel lining is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of existing railway tunnel lining maintenance, and in particular to a method and structure for treating cavity damage behind an existing railway tunnel lining. Background Art

[0002] Tunnel lining is a permanent support structure that supports and maintains the long-term stability of the tunnel. It is an important part of the tunnel structure. Its performance is closely related to the early design and construction of the tunnel and the surrounding environment in the later stage. In the early design and construction of the tunnel, due to the limitations of construction conditions, blasting excavation is often used, which is very easy to cause over-excavation. If the over-excavation part is not effectively treated in time, a cavity will often form behind the tunnel lining. In addition, with the increase in the service life of existing railway tunnels, the surrounding rock behind the tunnel lining often falls off due to various reasons, which will directly hit the lining concrete structure, resulting in severe impact or local over-accumulation of the lining concrete, uneven force, and cracking in severe cases. In addition, when the tunnel lining is in a complex water-bearing geological area, the fissure water will continue to converge to the cavity, resulting in tunnel leakage. In cold northern regions, the lining will also be subjected to greater destructive force due to the freezing and expansion of the leakage water. If the above lining diseases are not treated in time, tunnel leakage and block falling may occur at the least, or seriously endanger the running safety of trains. Therefore, in order to ensure the efficient operation of my country's railways and the personal safety of passengers, it is necessary to timely and effectively treat the cavity diseases behind the existing tunnel linings.

[0003] The commonly used treatment measure for the cavity disease behind the existing tunnel lining is grouting technology. This technology uses grouting equipment to inject grouting material into the cavity behind the tunnel lining under pressure, and uses the high fluidity of the grouting material to achieve filling of the cavity. Among them, the most commonly used grouting material is ordinary cement slurry. Cement slurry can achieve high fluidity with the help of admixtures. However, due to the uncertainty of the shape, size and capacity of the cavity behind the tunnel lining, the required amount of slurry during actual construction cannot be estimated, and the high fluidity and long setting time of cement slurry often cause the grouting liquid to exceed the treatment range, thereby causing problems such as waste of cement slurry. There is also an existing technology that uses sulphoaluminate cement slurry for grouting, but it is also difficult to achieve the design purpose. In addition, this existing technology also has an extremely important safety hazard, that is, after the existing railway construction skylight is completed, if the grouting material has not solidified and flows out from a crack in the lining concrete somewhere, this will cause a short circuit in the electrified railway contact network, thereby causing a safety incident and affecting driving safety. And most importantly, the higher density of ordinary cement slurry will also increase the load on the lining, which is likely to cause secondary damage to the tunnel lining.

[0004] There is also prior art that discloses that highway tunnel projects use foamed concrete as grouting material to reduce the load on the lining. However, compared with existing railway tunnels, highway tunnel projects do not have the limitation of "construction skylight time", so the foamed concrete used may not have performance requirements in terms of setting time and early strength; in addition, the preparation of foamed concrete requires the use of a cement foaming machine, which will undoubtedly increase the complexity of construction. For this reason, with regard to the treatment of the defects of the cavities behind the lining of existing railway tunnels, in order to complete the treatment work safely, economically and efficiently within the limited construction skylight time, it is urgent to develop a treatment method and structure suitable for the defects of the cavities behind the lining of existing railway tunnels. Summary of the invention

[0005] In view of this, the main purpose of the present invention is to provide a method and structure for treating the cavity disease behind the lining of an existing railway tunnel. The technical problem to be solved is to use low-elasticity lightweight grouting material to fill and reinforce the cavity behind the tunnel lining, so that the cavity disease behind the tunnel lining after treatment is significantly improved, and the stability of the tunnel lining structure is greatly improved.

[0006] The purpose of the present invention and the technical problem solved are achieved by adopting the following technical solutions: According to the present invention, a method for treating the cavity disease behind the lining of an existing railway tunnel includes filling and reinforcing with a low-elasticity lightweight grouting material.

[0007] The purpose of the present invention and the solution to its technical problems can be further achieved by adopting the following technical measures.

[0008] Preferably, in the aforementioned method for remediating cavity defects behind the lining of an existing railway tunnel, the filling and reinforcement of the low-elasticity lightweight grouting material includes: arranging grouting holes → drilling grouting holes → installing grouting pipes → making slurry → grouting → pulling out the pipes and sealing the holes.

[0009] Preferably, in the aforementioned method for treating cavity defects behind the lining of an existing railway tunnel, in the step of arranging grouting holes, the circumferential spacing of the holes in the tunnel is 2m±0.1m, and the longitudinal spacing is 1.5m±0.1m.

[0010] Preferably, in the aforementioned method for treating void defects behind the lining of an existing railway tunnel, in the step of drilling grouting holes, the drilling method is vertical drilling, the hole depth is greater than or equal to the designed depth, and the hole diameter is 38 to 50 mm.

[0011] Preferably, in the aforementioned method for treating cavity defects behind the lining of an existing railway tunnel, in the step of installing the grouting pipe, the length of the grouting pipe penetrates 30 to 50 cm into the surrounding rock layer; the grouting pipe is a detachable grouting pipe equipped with a grouting stopper.

[0012] Preferably, in the aforementioned method for treating the cavity defects behind the lining of an existing railway tunnel, the grouting pressure of the low-elastic lightweight grouting material for reinforcement is 0.2-0.4 MPa, and the grouting sequence is to inject section by section along the axial direction of the tunnel and to inject sequentially from the arch waist to the arch crown along the transverse direction of the tunnel; the grouting is stopped after the grouting pressure reaches the designed final pressure for 5 minutes.

[0013] Preferably, in the aforementioned method for treating void defects after lining of an existing railway tunnel, the preparation step of the low-elasticity lightweight grouting material includes: stirring water and powder A of the low-elasticity lightweight grouting material at a weight ratio of 0.3 to 0.4 for 3 to 5 minutes to form a slurry, stirring powder B and water at a weight ratio of 1:30 to 35 for 3 to 5 minutes to form a uniform foam, adding the foam after stirring powder B to the slurry after stirring powder A at 8% to 10% of the mass percentage of powder A, stirring for 1 to 2 minutes, adding liquid C to the slurry after stirring powder B at 5% to 8% of the mass percentage of powder A, stirring for 2 to 3 minutes, to obtain the low-elasticity lightweight grouting material.

[0014] Preferably, in the aforementioned method for treating void defects behind the lining of an existing railway tunnel, the stirring speed in the step of preparing the low-elasticity lightweight grouting material is above 1500 r / min.

[0015] Preferably, in the aforementioned method for treating the cavity disease behind the lining of an existing railway tunnel, the powder A of the low-elasticity lightweight grouting material is composed of 70-80 parts of 42.5 ordinary Portland cement, 10-15 parts of 42.5 sulphoaluminate cement, 4-6 parts of anhydrite, 3-5 parts of silica fume, and 0.05-0.1 parts of water reducer in parts by mass; the powder B is composed of 100 parts of sodium dodecylbenzene sulfonate. The liquid C is composed of 20-30 parts of methyl methacrylate, 0.1-0.3 parts of persulfate, 0.4-0.7 parts of ferrous salt, and 60-70 parts of water in parts by mass.

[0016] Preferably, in the above-mentioned method for treating cavity defects after railway tunnel lining, the low-elasticity lightweight grouting material has an initial setting time of ≤20min, a final setting time of ≤30min, and a dry density of ≤290kg / m 3 The elastic modulus is 60-80MPa, it is impermeable for 10min under 0.2Mpa conditions, and the compressive strength is ≥1.0MPa at 28d.

[0017] The purpose of the present invention and the solution of its technical problems can also be achieved by the following technical solutions. According to the present invention, a cavity disease treatment structure behind the existing railway tunnel lining includes an existing lining and surrounding rock arranged behind the lining; the lining is provided with a plurality of grouting holes penetrating the lining, elastic lightweight grouting material is injected into the grouting holes, and an elastic lightweight grouting material layer is provided between the lining and the surrounding rock.

[0018] Preferably, in the aforementioned structure for treating the cavity defects behind the lining of an existing railway tunnel, the grouting holes partially extend into the surrounding rock.

[0019] Preferably, in the aforementioned structure for treating void defects behind the lining of an existing railway tunnel, a grouting pipe is provided in the grouting hole, and an elastic lightweight grouting material layer is provided in the grouting pipe.

[0020] Preferably, in the aforementioned structure for treating void defects behind the lining of an existing railway tunnel, the elastic modulus of the low-elasticity lightweight grouting material layer is 60 to 80 MPa.

[0021] Preferably, in the aforementioned structure for remediating cavity defects behind the lining of an existing railway tunnel, the grouting pipe includes a flower pipe and a thread connected to the flower pipe as an integral whole, the outer portion of the flower pipe is provided with two sleeves and a grouting-stopping sleeve, the grouting-stopping sleeve is arranged between the two sleeves, the bottom end of the sleeve is connected to the flower pipe, and the flower pipe is connected to a nut via a thread.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The present invention proposes a method for treating the cavity disease behind the existing railway tunnel lining, which uses an elastic lightweight grouting material. Compared with traditional cement-based grouting materials, this material has a lower dry density and elastic modulus due to the addition of powder B and liquid C. Therefore, on the one hand, when the lining cavity maintains the same fullness, the lightweight characteristics of the material can greatly reduce the secondary load on the tunnel lining. On the other hand, when the tunnel lining is subjected to the same impact load, the low elasticity and seismic resistance of the material can greatly buffer the destructive effect on the tunnel lining. In addition, by adding liquid C to powder A, a cross-interpenetrating structure of organic polymer film and inorganic material is constructed in the microstructure system of the elastic lightweight grouting material. This structure enables the elastic lightweight grouting material mixed and prepared in a specific proportion to have better waterproof performance.

[0024] The present invention proposes a method for treating the cavity disease behind the existing railway tunnel lining, which uses a low-elasticity lightweight grouting material. Compared with the foam concrete used for highway tunnel lining, it has a faster setting time, so it can ensure that the grouting material is solidified within a shorter construction window time, thereby ensuring the safety and efficiency of the construction; secondly, since the preparation of this material does not require special foaming equipment, the construction is simple and easy to operate, and the construction cost is low.

[0025] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and make the above and other purposes, features and advantages of the present invention more understandable, the following specifically cites preferred embodiments and illustrates them with drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of a structure for treating cavity damage behind an existing railway tunnel lining according to an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of hole arrangement of elastic lightweight grouting material according to an embodiment of the present invention;

[0028] Figure 3 is a schematic diagram of a grouting pipe according to an embodiment of the present invention;

[0029] Figure 4 is a schematic diagram of survey line arrangement according to an embodiment of the present invention;

[0030] Figure 5 This is one of the geological radar detection images of the 728-743 section before grouting treatment using conventional cement grouting material in the present invention;

[0031] Figure 6 This is one of the geological radar detection images of the 728-743 section after grouting treatment using conventional cement grouting material in the present invention;

[0032] Figure 7 This is the second geological radar detection image of the 728-743 section before grouting treatment using conventional cement grouting material in the present invention;

[0033] Figure 8 This is the second geological radar detection image of the 728-743 section after grouting treatment using conventional cement grouting material in the present invention;

[0034] Fig. 9 This is the third geological radar detection image of the 728-743 section before grouting treatment using conventional cement grouting material in the present invention;

[0035] Fig.10This is the third geological radar detection image of the 728-743 section after grouting treatment using conventional cement grouting material in the present invention;

[0036] Fig.11 This is one of the geological radar detection images of the segment 1515-1530 before grouting treatment using low-elasticity lightweight grouting material in the present invention;

[0037] Fig.12 This is one of the geological radar detection images of the segmentation mark 1515-1530 section after grouting treatment using low-elasticity lightweight grouting material in the present invention;

[0038] Fig.13 This is the second geological radar detection image of the segment 1515-1530 before grouting treatment using low-elasticity lightweight grouting material in the present invention;

[0039] Fig.14 This is the second geological radar detection image of the segmentation mark 1515-1530 section after grouting treatment using low-elasticity lightweight grouting material in the present invention;

[0040] Fig.15 This is the third geological radar detection image of the segmentation mark 1515-1530 section before grouting treatment using low-elasticity lightweight grouting material in the present invention;

[0041] Fig.16 This is the third geological radar detection image of the segmentation mark 1515-1530 section after grouting treatment using low-elasticity lightweight grouting material in the present invention.

[0042] Among them, surrounding rock-1; lining-2; grouting hole-3; low-elasticity lightweight grouting material-4; grouting pipe-5; flower pipe-6; casing-7; grouting casing-8; nut-9; thread-10. DETAILED DESCRIPTION

[0043] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description of a method and structure for treating the cavity disease behind the lining of an existing railway tunnel proposed by the present invention in combination with the accompanying drawings and preferred implementation cases. The specific implementation methods, structures and their effects are described in detail as follows. Based on the described embodiments of the present invention, all other implementation cases obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] Unless otherwise defined, the technical or scientific terms used herein shall have the common meanings understood by persons with ordinary skills in the field to which the present invention belongs. The following materials, unless otherwise specified, were purchased.

[0045] Some implementation cases of the present invention provide a method for treating the cavity disease behind the lining of an existing railway tunnel, including filling and reinforcing with a low-elasticity lightweight grouting material. This arrangement can absorb or disperse the impact load of part of the surrounding rock falling blocks, greatly reduce the secondary load of the tunnel lining, and produce a certain waterproof effect on the surrounding rock seepage water, while ensuring that the grouting filling has a high degree of filling.

[0046] Since the low-elasticity lightweight grouting material has excellent performance characteristics such as fast setting, light weight, low elasticity shock absorption, and waterproofness, the present invention can not only complete the filling within a shorter skylight time, but also absorb or disperse part of the impact load of the falling surrounding rock, greatly reduce the secondary load of the tunnel lining, and produce a certain waterproof effect on the surrounding rock leakage.

[0047] In the technical solutions of some implementation cases, the filling and reinforcement of the low-elasticity lightweight grouting material may optionally include: arranging grouting holes → drilling grouting holes → installing grouting pipes → slurry making → grouting → pulling out the pipes and sealing the holes. The arranging of grouting holes is to lay out the lines on the tunnel lining surface according to the design, and mark the grouting hole positions with a marker, see Figure 1-Figure 2 .

[0048] In the above technical solution, optionally, in the step of arranging grouting holes, the circumferential hole spacing of the low-elasticity lightweight grouting material in the tunnel is 2m±0.1m, and the longitudinal hole spacing of the tunnel is 1.5m±0.1m. This can ensure that the low-elasticity lightweight grouting material can be more fully poured into the diseased area, and can ensure that the grouting filling has a high degree of filling; at the same time, existing contact wires, contact poles, cables and other equipment should be avoided.

[0049] In the above technical solution, optionally, in the step of drilling the grouting hole, the drilling is performed by a pneumatic drill, the drilling method can be vertical drilling, the hole diameter is within the range of 38 to 50 mm, and the hole depth is not less than the designed depth. The purpose of the hole depth being not less than the designed depth is to ensure that the slurry can be more fully injected into the diseased part after the tunnel lining, and more effectively ensure its reinforcement and waterproofing effect.

[0050] In the above technical solution, optionally, in the step of installing the grouting pipe, the length of the grouting pipe should be determined according to the thickness of the existing lining, and the grouting pipe needs to be penetrated into the surrounding rock layer by 30 to 50 cm, the purpose of which is to enhance the diffusion of the filling material into the surrounding rock to achieve reinforcement and waterproofing effects; in order to ensure higher construction efficiency and better grouting effect, the pipe head of the grouting pipe is provided with a grouting plug, which prevents the grouting material from overflowing.

[0051] In the above technical solution, optionally, the reinforcement of the low-elasticity lightweight grouting material can be ensured by stirring it 2-4 minutes in advance to ensure the hydration of the cementitious material and to fully exert its lightweight properties.

[0052] In the above technical solution, optionally, the grouting pressure of the low-elastic lightweight grouting material for reinforcement is 0.2-0.4 MPa, and the grouting sequence is to adopt a segmented grouting method along the axial direction of the tunnel and a sequential injection method from the arch waist to the arch crown along the transverse direction of the tunnel. The grouting is terminated after 4-6 minutes when the grouting pressure reaches the designed final pressure.

[0053] In the above technical solution, optionally, in the slurry making step, the preparation step of the low elastic light grouting material includes: quickly stirring water and powder A of the low elastic light grouting material at a weight ratio of 0.3 to 0.4 for 3 to 5 minutes to form a slurry, and quickly stirring powder B and water at a weight ratio of 1:30 to 35 for 3 to 5 minutes to form a uniform foam, adding the foam after stirring powder B to the slurry after stirring powder A at 8% to 10% of the mass percentage of powder A, and quickly stirring for 1 to 2 minutes, and adding liquid C to the slurry after stirring powder B at 5% to 8% of the mass percentage of powder A, and quickly stirring for 2 to 3 minutes to obtain the low elastic light grouting material; the purpose of such setting is to ensure that the grouting material has the properties of high fluidity, fast setting, light weight, low elasticity and waterproof. The low elastic light grouting material consists of powder A, powder B and liquid C. The powder A of the low-elasticity lightweight grouting material is composed of 70-80 parts of 42.5 ordinary silicate cement, 10-15 parts of 42.5 sulphoaluminate cement, 4-6 parts of anhydrite, 3-5 parts of silica fume, and 0.05-0.1 parts of water reducer according to the mass fraction; the powder B is composed of 100 parts of sodium dodecylbenzene sulfonate according to the mass fraction. The liquid material C is composed of 20-30 parts of methyl methacrylate, 0.1-0.3 parts of persulfate, 0.4-0.7 parts of ferrous salt, and 60-70 parts of water according to the mass fraction. Within this limit range, a grouting material with high fluidity, fast setting, light weight, low elasticity and waterproofness can be obtained.

[0054] In the above technical solution, optionally, in order to ensure sufficient hydration of the cementitious material and full play of its lightweight properties, the stirring speed in the low-elasticity lightweight grouting material preparation step is set to be above 1500r / min.

[0055] In the above technical solution, optionally, in order to ensure the large filling degree, fast setting, light weight, low elasticity, shock resistance and waterproof characteristics of the low elasticity lightweight grouting material, the initial setting time of the low elasticity lightweight grouting material is ≤20min, and the final setting time is

[0056] ≤30min, dry density ≤290kg / m 3 The elastic modulus is 60-80MPa, it is impermeable for 10min under 0.2Mpa conditions, and the compressive strength is ≥1.0MPa at 28d.

[0057] In the above technical solution, optionally, the step of pulling out the pipe and sealing the hole is: it is necessary to immediately close the orifice valve and disassemble and clean the pipeline after the grouting stops, and seal the orifice with a slurry stopper after the slurry solidifies to ensure that there is no seepage or leakage in the structure after the hole is sealed.

[0058] like Figure 1-Figure 2 As shown, some implementation cases of the present invention also provide a structure for treating the cavity disease behind the lining of an existing railway tunnel, including a lining 2 and a surrounding rock 1 arranged below the lining; the lining 2 is provided with a plurality of grouting holes 3 penetrating the lining 2, a low-elasticity lightweight grouting material layer is arranged in the grouting holes 3, and a low-elasticity lightweight grouting material layer is arranged between the lining 2 and the surrounding rock 1. This arrangement can absorb or disperse the impact load of part of the falling blocks of the surrounding rock, greatly reduce the secondary load of the tunnel lining, and produce a certain waterproof effect on the leakage of the surrounding rock, while ensuring that the grouting filling has a high degree of filling.

[0059] In the above technical solution, optionally, the grouting hole 3 partially extends into the surrounding rock 1, and this arrangement is to ensure the stability of the repair structure.

[0060] In the above technical solution, optionally, a grouting pipe 5 is provided in the grouting hole 3, and a low-elasticity lightweight grouting material layer is provided in the grouting pipe 5; the elastic modulus of the low-elasticity lightweight grouting material layer is 60-80 MPa.

[0061] In the above technical solution, optionally, the grouting pipe 5 includes a flower pipe 6 and a thread 10 connected to the flower pipe 8 as a whole, the outer sleeve of the flower pipe 6 is provided with two sleeves 7 and a grout-stopping sleeve 8, the grout-stopping sleeve 8 is arranged between the two sleeves 7, the bottom end of the sleeve 7 is connected to the flower pipe 6, and the flower pipe 6 is connected to a nut 9 through the thread 10, see Figure 3 ; This setting is to achieve better slurry diversion effect, while facilitating sealing and quick disassembly.

[0062] The present invention is further described below in conjunction with specific embodiments.

[0063] Example 1

[0064] This embodiment provides a method for treating cavity damage behind the lining of an existing railway tunnel, comprising the following steps:

[0065] 1) Arrange grouting holes for low-elastic lightweight grouting materials: the circumferential spacing of the holes in the tunnel is 2m, and the longitudinal spacing is 1.5m;

[0066] 2) Drilling grouting holes: Use pneumatic drilling equipment to drill holes vertically in the casing. The hole depth is 250cm and the hole diameter is Φ45mm.

[0067] 3) Install the grouting pipe: install the grouting pipe in the grouting hole of step 2), and set a grouting plug at the pipe head, and use the grouting liquid to block the space outside the pipe to prevent the grouting liquid from overflowing;

[0068] 4) Slurry preparation: 4 minutes in advance, water and low-elasticity lightweight grouting material are mixed in a weight ratio of 0.35:1, and rapidly stirred (1500r / min) for 4 minutes; the preparation steps of the low-elasticity lightweight grouting material include: water and powder A of the low-elasticity lightweight grouting material are fully stirred for 4 minutes in a weight ratio of 0.35 to form a slurry, powder B and water are rapidly stirred (1500r / min) for 4 minutes in a weight ratio of 1:33 to form a uniform foam, the foam after stirring powder B is added to the slurry after stirring powder A according to 9% of the mass percentage of powder A, and rapidly stirred (1500r / min). 2min, liquid C is added into the slurry after powder B is stirred according to 7% of the mass percentage of powder A, and quickly stirred (1500r / min) for 3min to obtain the low-elasticity lightweight grouting material; the low-elasticity lightweight grouting material is composed of powder A, powder B and liquid C; wherein the powder A of the low-elasticity lightweight grouting material is composed of 78 parts of 42.5 ordinary silicate cement, 13 parts of 42.5 sulphoaluminate cement, 5 parts of anhydrite, 4 parts of silica fume, 0.06 parts of polycarboxylic acid water reducer (water reduction rate is 25%) according to the mass percentage; the powder B is composed of 100 parts of sodium dodecylbenzene sulfonate. The liquid C is composed of 25 parts of methyl methacrylate, 0.2 parts of potassium persulfate, 0.5 parts of ferrous sulfate, and 70 parts of water according to the mass percentage. The initial setting time of the low-elastic lightweight grouting material is 18 minutes, the final setting time is 25 minutes, and the dry density is 288 kg / m 3 The elastic modulus is 71MPa, it is impermeable for 10min under 0.2Mpa conditions, and the compressive strength is 1.2MPa at 28d.

[0069] 5) Grouting of low-elasticity lightweight grouting material: The grouting pressure used is 0.3MPa. In order to ensure the quality of grouting, the grouting sequence is to inject section by section along the axis of the tunnel and inject from the arch waist to the arch crown along the transverse direction of the tunnel. The grouting is terminated after 5 minutes when the grouting pressure reaches the designed final pressure (0.3MPa).

[0070] 6) Pull out the pipe and seal the hole: After the grouting stops, immediately close the orifice valve and dismantle and clean the pipeline. After the slurry solidifies, seal the orifice with a grouting plug.

[0071] Test Example

[0072] The geological radar method is used to detect the lining disease treatment section before and after grouting. The following selects two sections of lining with a length of 5 meters for a certain existing tunnel lining with void disease, and uses conventional cement-based grouting material grouting (the difference between comparative example 1 and example 1 is that the grouting type is conventional cement-based grouting material, and the conventional cement-based grouting material is composed of 42.5 ordinary silica cement, with a water-cement ratio of 0.8) grouting, and the remaining steps and parameters are the same as example 1) and low elasticity lightweight grouting material grouting (example 1) for grouting reinforcement treatment. Geological radar detection is performed on various grouting methods before and after grouting treatment in accordance with the "Regulations for Nondestructive Testing of Railway Tunnel Lining Quality" TB10223-2004 and "Railway Engineering Physical Exploration Specifications" TB10013-2010. The detection range covers 5 meters before and after the grouting section, with a total length of 15 meters. The detection instrument is the SIR-3000 portable single-channel geological radar and its matching 400MHz antenna produced by GSSI, USA.

[0073] In order to more comprehensively and truly characterize the effect of disease treatment, the lining disease treatment section before and after grouting was tested by geological radar at the side line position and side line length (three lines - S1, S2 and S3) arranged on the left and right arch haunches and arch crowns along the line direction. The specific arrangement of geological radar detection lines can be found in Figure 4 shown.

[0074] Conventional cement-based grouting materials and the low-elasticity lightweight grouting materials of Example 1 were used to treat different sections of lining defects on the same railway line. The specific section mileage and inspection workload are shown in Tables 1 and 2, respectively.

[0075] Table 1 Workload of geological radar detection in the conventional cement grouting treatment section

[0076]

[0077] Table 2 Geological radar detection workload in the low-elasticity lightweight grouting material grouting treatment section

[0078]

[0079] The tunnel was grouted with conventional cement-based grouting materials in the 728-743 section of the dividing mark. A total of two geological radar tests were conducted before and after the grouting treatment. The results of the two geological radar tests before and after are now compared and analyzed. The specific comparison results are shown in Table 3 and Figure 5-Figure 10 shown.

[0080] Table 3 Comparative analysis of geological radar detection results before and after conventional cement grouting treatment in the 728-743 section of the dividing mark

[0081]

[0082] The 1515-1530 section of the tunnel, which was grouted with low-elastic lightweight grouting material, was tested twice by geological radar before and after grouting. The results of the two geological radar tests are compared and analyzed. The specific comparison results are shown in Table 4 and Figure 11-Figure 16 shown.

[0083] Table 4 Comparative analysis of geological radar detection results before and after grouting of low-elastic lightweight grouting materials in the 1515-1530 section of the division mark

[0084]

[0085] Through Table 3~Table 4 and Figure 5-Figure 16 The results of the analysis and comparison show that the grouting method using conventional cement grouting material has insufficient filling of the voids behind the existing lining, that is, there is still a phenomenon of de-voiding. After the low-elasticity lightweight grouting material of the present invention is used, the filling of the voids behind the lining is significantly improved, and the phenomenon of internal de-voiding has been basically eliminated. This shows that the treatment method provided by the present invention can well treat the void disease behind the tunnel lining, and the structure after treatment is more stable. The reason is that the low-elasticity lightweight grouting material of the present invention is composed of three different types of materials. These materials can be combined with other materials for synergistic optimization while playing their respective advantages, thereby improving the comprehensive performance. Among them, while ensuring that the grouting material has excellent working performance, the synergistic effect of powder A and powder C enables a cross-interpenetrating structure of organic polymer film and inorganic material to be constructed in the microstructure system of the elastic lightweight grouting material. This structure enables the elastic lightweight grouting material mixed and modulated in a specific proportion to have better waterproof performance; while powder B ensures that the grouting material has a lower dry density, the synergistic effect of powder B and powder C enables the grouting material to have a lower elastic modulus. It can be seen that under the synergistic combination optimization effect of the above three materials, the structural stability after the treatment of the present invention is significantly improved.

[0086] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0087] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

[0088] The above embodiments are only exemplary embodiments of the present invention and are not intended to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions shall also be deemed to fall within the protection scope of the present invention.

Claims

1. A method for treating the cavity disease behind the lining of an existing railway tunnel, characterized in that: Includes filling and reinforcement of low-elastic lightweight grouting materials.

2. The method for treating the cavity disease behind the lining of an existing railway tunnel as claimed in claim 1, characterized in that: The filling and reinforcement of the low-elasticity lightweight grouting material includes: arranging grouting holes → drilling grouting holes → installing grouting pipes → making slurry → grouting → pulling out the pipes and sealing the holes.

3. The method for treating the cavity disease behind the lining of an existing railway tunnel as claimed in claim 2, characterized in that: In the step of arranging grouting holes, the circumferential hole spacing of the tunnel is 2m±0.1m, and the longitudinal spacing is 1.5m±0.1m; in the step of drilling grouting holes, the drilling method is vertical drilling, and the hole diameter is 38-50mm; in the step of installing the grouting pipe, the length of the grouting pipe penetrates into the surrounding rock layer by 30-50cm; the grouting pipe adopts a detachable grouting pipe equipped with a grouting stopper.

4. The method for treating the cavity disease behind the lining of an existing railway tunnel as claimed in claim 1, characterized in that: The reinforcement of the low-elastic lightweight grouting material has a grouting pressure of 0.2-0.4 MPa, and the grouting sequence is to inject section by section along the tunnel axis and to inject sequentially from the arch waist to the arch crown along the tunnel transverse direction; the grouting is terminated 5 minutes after the grouting pressure reaches the designed final pressure.

5. The method for treating the cavity disease behind the lining of an existing railway tunnel as claimed in claim 1, characterized in that: The preparation steps of the low-elasticity lightweight grouting material include: stirring water and powder A of the low-elasticity lightweight grouting material at a weight ratio of 0.3 to 0.4 for 3 to 5 minutes to form a slurry, stirring powder B and water at a weight ratio of 1:30 to 35 for 3 to 5 minutes to form uniform foam, adding the foam after stirring powder B to the slurry after stirring powder A at 8% to 10% of the mass percentage of powder A, stirring for 1 to 2 minutes, adding liquid C to the slurry after stirring powder B at 5% to 8% of the mass percentage of powder A, stirring for 2 to 3 minutes, and obtaining the low-elasticity lightweight grouting material.

6. The method for treating the cavity damage behind the lining of an existing railway tunnel as claimed in claim 5, characterized in that: The stirring speed in the step of preparing the low-elasticity lightweight grouting material is above 1500r / min.

7. The method for treating the cavity disease behind the lining of an existing railway tunnel as claimed in claim 5, characterized in that: The powder A of the low-elastic lightweight grouting material is composed of 70-80 parts of 42.5 ordinary silicate cement, 10-15 parts of 42.5 sulphoaluminate cement, 4-6 parts of anhydrite, 3-5 parts of silica fume, and 0.05-0.1 parts of water reducer in parts by mass; the powder B is composed of 100 parts of sodium dodecylbenzene sulfonate; the liquid C is composed of 20-30 parts of methyl methacrylate, 0.1-0.3 parts of persulfate, 0.4-0.7 parts of ferrous salt, and 60-70 parts of water in parts by mass.

8. The method for treating the cavity disease behind the lining of an existing railway tunnel as claimed in claim 5, characterized in that: The low-elasticity lightweight grouting material has an initial setting time of ≤20min, a final setting time of ≤30min, and a dry density of ≤290kg / m 3 The elastic modulus is 60-80MPa, it is impermeable for 10min under 0.2Mpa conditions, and the compressive strength is ≥1.0MPa at 28d.

9. A structure for treating the cavity damage behind the lining of an existing railway tunnel, characterized in that: It includes an existing railway tunnel lining and surrounding rock arranged behind the lining; the lining is provided with a plurality of grouting holes penetrating the lining, low-elasticity lightweight grouting material is injected into the grouting holes, and a low-elasticity lightweight grouting material layer is provided between the lining and the surrounding rock.

10. The structure for treating the cavity damage behind the existing railway tunnel lining as claimed in claim 9, characterized in that: The grouting hole partially extends into the surrounding rock; a grouting pipe is provided in the grouting hole, and a low-elasticity lightweight grouting material layer is provided in the grouting pipe, and the elastic modulus of the low-elasticity lightweight grouting material layer is 60-80 MPa; the grouting pipe includes a flower pipe and a thread connected to the flower pipe as a whole, the outer sleeve of the flower pipe is provided with two sleeves and a grouting-stopping sleeve, the grouting-stopping sleeve is arranged between the two sleeves, the bottom end of the sleeve is connected to the flower pipe, and the flower pipe is connected to a nut through a thread.

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