A grouting construction method and grouting structure for tunnels passing close to existing railway lines

Abstract

This invention relates to a grouting construction method and grouting structure for a tunnel passing close to an existing railway line. The method includes at least: removing a pre-defined original soil layer between the tunnel and the existing railway line while supporting the existing line; setting at least one load-bearing layer (3) in the original soil layer area between the tunnel and the existing line to support the existing line; wherein the load-bearing layer (3) is a hexagonal grid structure nested among several load-bearing components (7) assembled in a splicing manner; and the nodes where the ends of several load-bearing components (7) converge form load-bearing columns by grouting. The grouting construction method of this invention has fewer grouting steps, lower grouting pressure, and the resulting grouting structure is lightweight, has strong bearing capacity, and good stability, which can both avoid deformation of the existing railway line and reduce the pressure on the tunnel.

Description

Technical Field

[0001] This invention relates to the field of tunnel underpass technology, and in particular to a grouting construction method and grouting structure for tunnels passing close to existing railway lines. Background Technology

[0002] In existing technologies, when constructing tunnels under existing subway stations and sections, the distance between the tunnel and the existing railway structure is within 0-2 meters. The engineering geology and hydrogeology of the environment involved in the tunnel are disturbed, and the strata between the two structures are relatively thin. Technical measures cannot effectively reinforce the strata, so the existing railway is prone to deformation during construction.

[0003] In existing technologies, grouting of the soil layer between the tunnel and the existing railway line often fails to fully flow to the required stratum, resulting in poor grouting effectiveness. This necessitates repeated grouting and constant monitoring of the existing railway line's subsidence. Furthermore, adjustments to the grouting plan and angle are required when subsidence occurs. Therefore, traditional grouting methods are ineffective, time-consuming, and provide inconsistent support for the existing railway line.

[0004] For example, patent document CN104265307B discloses a construction method for a shield tunnel with earth pressure balance in uneven strata to pass under an existing railway line. The specific steps are: 1. Mathematical simulation analysis of the underpass conditions; 2. Setting construction parameters; 3. Shield tunneling construction: A. Setting tunneling parameters; B. Setting the shield tunneling direction; C. Setting synchronous grouting; D. Setting secondary grouting; 4. Segment assembly; 5. Shield tail protection. This invention studies a construction method for a shield tunnel with earth pressure balance in uneven strata to pass under an existing railway line. This method enables the safe operation of the existing railway line while the shield tunnel is safely constructed and passes under the existing railway line. However, the grouting construction method of this invention is still a traditional grouting method, which achieves soil reinforcement through repeated grouting, resulting in the drawback of repeated grouting.

[0005] The present invention aims to provide a grouting structure that can be directly installed between the tunnel and the existing railway line without grouting the soil layer, thereby preventing deformation of the existing railway line and enabling the tunnel to pass under it safely.

[0006] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the inventors studied a large number of documents and patents when making this invention, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that the present invention does not possess the features of these prior art. On the contrary, the present invention already possesses all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Summary of the Invention

[0007] In existing technologies, grouting of the soil layer between the tunnel and the existing railway line often fails to fully flow to the required stratum, resulting in poor grouting effectiveness. This necessitates repeated grouting and constant monitoring of the existing railway line's subsidence. Furthermore, adjustments to the grouting plan and angle are required when subsidence occurs. Therefore, traditional grouting methods are ineffective, time-consuming, and provide inconsistent support for the existing railway line.

[0008] The present invention aims to provide a grouting structure that can be directly installed between the tunnel and the existing railway line without grouting the soil layer, thereby preventing deformation of the existing railway line and enabling the tunnel to pass under it safely.

[0009] This invention provides a grouting construction method for tunnels passing close to existing railway lines. The method includes at least: removing a pre-defined original soil layer between the tunnel and the existing railway line while supporting the existing line; setting at least one load-bearing layer in the original soil layer area between the tunnel and the existing line to support the existing line; wherein the load-bearing layer is a nested hexagonal grid structure composed of several load-bearing components; and the nodes where the ends of several load-bearing components converge form load-bearing columns by grouting. This grouting construction method allows for step-by-step operation within various small-sized pilot tunnels, saving construction time. Furthermore, by removing the original soil layer, unstable factors causing settlement of the existing line are eliminated. The newly constructed grouting structure, a nested hexagonal grid structure, is stable and not easily deformed, providing sufficient support for the existing line and preventing settlement, thus ensuring the safety of the existing line. The grouting structure has sufficient support for the existing line, and due to the numerous cavities in the grid structure, the overall weight of the grouting structure is relatively light, avoiding excessive pressure on the subsequently constructed tunnel. During subsequent tunnel construction, supporting the grouting structure becomes easier, reducing the number of support tools, expanding the construction space, and improving the safety of tunnel construction.

[0010] Preferably, the method further includes: a plurality of load-bearing components of equal length are distributed around a node at an angle of 60 degrees and / or 120 degrees to each other, thereby forming a nested hexagonal grid structure of the load-bearing components of equal length.

[0011] Preferably, the nested hexagonal grid structure includes: a plurality of rhomboid grid cells composed of load-bearing components abutting against each other to form a nested hexagonal grid, so that the force applied to the node by each load-bearing component is canceled out and / or dispersed by the adjacent load-bearing components.

[0012] The load-bearing components of this invention are designed as nested hexagonal grids, which are not only less prone to deformation, but also offer the advantage of numerous triangular regions within the rhomboid units. These triangular regions exhibit greater lateral stiffness, increasing the horizontal load-bearing capacity of the load-bearing components and effectively resisting lateral movement. The load-bearing components are simple grouting piles, with a simplified grouting method that reduces the use of large machinery. The grid-like grouting structure also reduces the amount of grout required. Therefore, the grouting structure offers low economic cost, requires less machinery, has a simple grouting method, and streamlines the grouting process, thus having a positive impact on construction.

[0013] In existing technologies, if simple piles or grouting walls are used as load-bearing components, the workload of construction workers will not be reduced, and the piles are heavy and difficult to move. Therefore, if the angle of a load-bearing component deviates, it is not easy for construction workers to make timely adjustments before grouting. To solve this problem, the present invention uses hollow piles with a special structure as load-bearing components, reducing the overall weight of the load-bearing components without weakening their supporting capacity.

[0014] The load-bearing component is a hollow grouting pile body. The load-bearing component includes at least a grouting part and a shaping part. The shaping part includes grouting grooves distributed in a grid. The grouting part is a cavity communicating with the grouting grooves. Thus, when the horizontal height of the shaping part is lower than the horizontal height of the grouting part, the grout in the grouting part fills the grouting grooves based on gravity and forms a geometric support column that supports the grouting part.

[0015] The load-bearing component of the present invention forms a grid structure with supporting capacity after grouting in the shaped part, thereby increasing the supporting force while reducing the weight of the load-bearing component. This makes it easier for construction personnel to move or adjust the position and angle using tools, reducing the difficulty of construction work and reducing the pressure exerted on the bottom by the load-bearing component.

[0016] Preferably, the non-grouting end and / or the wall of the grouting section of the load-bearing component are provided with a plurality of overflow holes. During grouting, excess grout within the load-bearing component overflows from the overflow holes at the non-grouting end. The overflowing grout, when blocked or overflowing from load-bearing components at the same node, forms a load-bearing column. Alternatively, excess grout within the load-bearing component overflows from the overflow holes in the wall of the grouting section, connecting the load-bearing component to the existing line and / or soil layer above it. Preferably, the overflowing grout from the load-bearing component forms a reinforcing part that fixes the load-bearing component, connecting it to the existing line, surrounding soil layer, or bottom concrete layer, avoiding the drawbacks of repeated grouting by construction personnel. Construction personnel only need to grout once to simultaneously form the load-bearing component, load-bearing column, reinforcing part, etc. When a load-bearing component at the edge of the load-bearing layer needs to be inserted into the surrounding soil layer or rock, the grout can also fix the load-bearing component relatively to the surrounding environment.

[0017] Preferably, the grouting groove of the load-bearing component is constructed by a number of protruding hollow structures at intervals, so that the grouting groove has a regular geometric grid shape, which is conducive to forming a hexagonal grid structure through the grouting groove to improve the grid-like support force.

[0018] Preferably, the load-bearing component is disposed on at least one layer of concrete and is integrally grouted with the concrete layer, the concrete layer being disposed at a horizontal position at the top of the tunnel.

[0019] Preferably, the bottom of the grouting groove is provided with at least one overflow hole, so that during grouting, grout overflows from the overflow hole at the bottom to connect the load-bearing component to the concrete layer as a whole. This arrangement makes the load-bearing component more stable.

[0020] The present invention also provides a grouting structure for a tunnel passing close to an existing railway line. In the case of removing the original soil layer between the tunnel and the existing railway line, the grouting structure includes at least one load-bearing layer. The load-bearing layer is a hexagonal grid structure nested together by splicing several load-bearing components. The nodes at the ends of several load-bearing components are grouted to form load-bearing columns.

[0021] Preferably, the load-bearing component is a hollow grouting pile body, and the load-bearing component includes at least a grouting part and a shaping part. The shaping part includes grouting grooves distributed in a grid, and the grouting part is a cavity communicating with the grouting grooves. Thus, when the horizontal height of the shaping part is lower than the horizontal height of the grouting part, the grout in the grouting part fills the grouting grooves under the action of gravity and forms a geometric structural support for the grouting part.

[0022] The grouting structure of the present invention has a simple grouting method, can achieve a large supporting force with a small amount of grouting, and has a low weight, making it widely applicable to support scenarios in engineering construction. Attached Figure Description

[0023] Figure 1 This is a longitudinal cross-sectional structural schematic diagram of the load-bearing component of the present invention;

[0024] Figure 2 This is a structural schematic diagram of the end of the load-bearing component of the present invention.

[0025] Figure 3 This is a schematic diagram of the geometric structure layer of the load-bearing component of the present invention;

[0026] Figure 4 This is a structural schematic diagram of one vertical angle of the load-bearing layer of the present invention;

[0027] Figure 5 This is a schematic diagram of the load-bearing layer of the present invention at another vertical angle;

[0028] Figure 6 This is a macroscopic structural diagram of the existing line and tunnel of the present invention.

[0029] List of reference numerals

[0030] 1: Existing line; 2: First concrete layer; 3: Load-bearing layer; 4: Second concrete layer; 5: Reinforcement layer; 6: Tunnel; 7: Load-bearing component; 72: Shaping part; 73: Grouting part; 74: Hollow part; 76: Overflow hole; 77: First grouting hole; 78: Second grouting hole; 79: Third grouting hole; 8: Hollow structure; 9: Grouting groove. Detailed Implementation

[0031] The following is a detailed explanation with reference to the accompanying drawings.

[0032] This invention provides a grouting construction method and grouting structure for tunnels passing close to existing railway lines.

[0033] A grouting construction method for a tunnel passing close to an existing railway line, the method comprising at least the following:

[0034] S1: When supporting the existing line, remove the original soil layer between the pre-set tunnel and the existing line.

[0035] The method of supporting the existing railway line in this invention is as follows: After the parameters of the tunnel to be constructed are set, several small-sized working tunnels are set up in the area between the tunnel to be constructed and the existing railway line for phased construction. In the small-sized working tunnels, especially those close to the existing railway line, the soil layer near the existing railway line is removed, and jacks, piles, and / or beams are used to support the existing railway line, preventing temporary settlement. Simultaneously, due to the operational advantages of multiple small-sized working tunnels, part of the existing railway line is also supported by the original soil layer in the unconstructed area, reducing the impact of construction on the existing railway line. After the grouting structure in some of the small-sized working tunnels is formed and solidified, the grouting structure can form a solid structure to further support the existing railway line, making it more stable and preventing settlement. Therefore, after the existing railway line is supported by the grouting structure, the unconstructed original soil layer can be constructed. At this time, due to the increased support force, the existing railway line will not settle.

[0036] Preferably, the small working holes are arranged symmetrically, first on both sides and then in the middle.

[0037] S2: Set at least one load-bearing layer 3 in the original soil layer area between tunnel 6 and existing line 1 to support the existing line.

[0038] Preferably, the load-bearing layers 3 can be arranged at intervals or adjacently to form a whole.

[0039] The present invention is illustrated by taking a load-bearing layer set in a small working hole as an example.

[0040] like Figure 4 and Figure 5 As shown, the load-bearing components 7 are spliced ​​together to form a nested hexagonal grid structure, constituting the load-bearing layer 3. The nodes where the ends of several load-bearing components 7 converge are grouted to form load-bearing columns.

[0041] like Figure 4 As shown, several load-bearing components 7 of equal length are distributed around a node at an angle of 60 degrees and / or 120 degrees to each other, thereby forming a nested regular hexagonal grid structure.

[0042] like Figure 5 As shown, several rhomboid mesh units composed of load-bearing components 7 are joined together to form nested regular hexagonal meshes. This allows the forces applied to nodes by each load-bearing component 7 to be offset and / or dispersed by adjacent load-bearing components 7. Because the ends of the load-bearing components form triangular angles with other load-bearing components, when a load-bearing component bears a force and applies it to a load-bearing column, the force on the column can be decomposed into smaller forces layer by layer by the remaining load-bearing components. The mesh as a whole can decompose forces in all directions, preventing the load-bearing components from tilting and forming a stable mesh structure.

[0043] A node is formed by connecting several load-bearing components. Load-bearing columns are set up by casting or grouting to connect the various load-bearing components into a whole.

[0044] Preferably, load-bearing components can also be set in some of the rhomboid grid cells, so that some of the rhomboid grid cells form a more stable triangle, further improving the anti-tilting ability of the load-bearing components.

[0045] Preferably, the plane containing the load-bearing layer is divided into a main load-bearing area and an auxiliary load-bearing area. The main load-bearing area is the region close to the central axis of the existing line, for example, an area within 1 meter of the central axis. Within this area, load-bearing components are spliced ​​in a triangular pattern to improve their load-bearing capacity and resistance to tilting. In the auxiliary load-bearing area, load-bearing components are spliced ​​using diamond-shaped grid units. Therefore, as... Figure 5 As shown, triangular and rhomboid grid units can be orderly assembled to form an effective supporting load-bearing layer.

[0046] Preferably, the load-bearing layer between the tunnel and the existing line is not limited to one layer, but can also be two or even more layers.

[0047] If the distance between the tunnel and the existing railway line is less than 1 meter, the load-bearing layer can be set as one layer. If the distance between the tunnel and the existing railway line is greater than 1 meter, the load-bearing layer can be set as one layer, or even two or more layers.

[0048] Taking a two-layer load-bearing structure as an example, there is at least one horizontally arranged connecting plate layer between the first and second load-bearing layers to connect them. That is, the connecting plate layer is supported by the load-bearing components of the first layer, while the surface of the connecting plate layer is distributed with the load-bearing components of the second load-bearing layer.

[0049] Preferably, the rhomboid grid cells of the two load-bearing layers are arranged in a way that they are relatively staggered in the vertical direction, which helps the first load-bearing layer to further decompose the pressure applied to the connecting plate layer by the second load-bearing layer, making the first load-bearing layer more stable.

[0050] The connecting plate layer can be formed by casting or pre-prepared. The connecting plate layer can be connected to the first load-bearing layer and the second load-bearing layer by grouting or casting.

[0051] like Figures 1 to 3As shown, the load-bearing component 7 of this invention is a hollow grouting pile. The advantage of using a hollow pile is its lighter weight, which reduces the difficulty of movement for construction workers and the complexity of arranging the load-bearing component into a grid shape. For example, when construction workers use a light emitter to emit three visible rays at 120-degree angles to each other, and place the light emitter at a node position, the workers can move the load-bearing component according to the direction of the rays, allowing the load-bearing components to ultimately be assembled into a nested hexagonal grid structure.

[0052] Nested hexagonal grid structures refer to a distribution where two sides of three adjacent hexagons sharing the same node are connected to form a new hexagon, which in turn connects the original three hexagons, creating a nested distribution.

[0053] Existing hollow piles are relatively simple, with a hollow central section forming a geometric shape. However, such hollow piles cannot be used for support between tunnels and existing railway lines. This is because if several hollow piles are arranged vertically along their axes, the number of piles is large, the arrangement is cumbersome, and they are prone to displacement after installation, making it difficult to maintain a straight line. If several hollow piles are arranged horizontally along their axes, the overall load-bearing capacity is poor, making them susceptible to deformation under pressure. Furthermore, stacked hollow piles are unstable and cannot provide significant support.

[0054] Based on the deficiencies in the existing technology, this invention provides a novel grouting structure as a load-bearing component 7, taking into account the need for a pressure-bearing layer between the tunnel and the existing railway line.

[0055] like Figure 1 As shown, the external structure of the load-bearing component 7 is an elongated pile. The geometry of the cross-section of the load-bearing component is not limited; it can be rectangular, triangular, or polygonal. This invention uses an example with a rectangular cross-section to illustrate the internal structure.

[0056] like Figure 1 As shown, the load-bearing component 7 includes at least a grouting section 73 and a shaping section 72. When using the load-bearing component, the grouting section 73 is positioned higher than the shaping section 72. The height of the load-bearing component is not limited and can be set as needed. Preferably, the height of the load-bearing component is 0-1m, which lowers the overall center of gravity of the load-bearing component, thereby enhancing its anti-tilting ability. The height of the grouting section 73 is no more than one-quarter of the height of the load-bearing component, allowing the geometric support structure formed by the shaping section to better support the compressive layer or compressive strip formed by the grouting section, while reducing the overall grouting volume of the load-bearing component.

[0057] The shaping section 72 includes grouting grooves 9 arranged in a grid pattern. The gaps between the shaping section 72 and the wall section form the grouting section 73. The grouting section 73 and the shaping section 72 are connected.

[0058] When the horizontal height of the shaping section 72 is lower than the horizontal height of the grouting section 73, the grout in the grouting section 73 fills the grouting groove 9 under the action of gravity and forms a geometric support pillar for the grouting section 73. With the grouting cavity set up in this way, the resistance to the grout entering is small, and a high grouting pressure is not required; the grout flows into the grouting groove by gravity, which reduces the possibility of voids in the grouting groove.

[0059] The grouting groove 9 is constructed from several protruding hollow structures 8 spaced apart, giving the grouting groove 9 a regular geometric grid pattern. For example... Figure 1 As shown, the hollow structure 8 is formed by mechanically shaping the wall of the load-bearing component 7, so that the wall protrudes from the original horizontal position in the shape of a hollow structure. Alternatively, several hollow structures 8 are welded to the wall of the load-bearing component by constructing grouting grooves.

[0060] like Figure 3 As shown, the hollow structure 8 is a regular hexagon, and is arranged in a way that allows the grouting grooves 9 to form a regular hexagonal grid distribution, so that the grout in the grouting grooves 9 forms hexagonal structural supports after solidification. Or, as... Figure 5 As shown, the hollow structure 8 is a rhombus structure, and the grouting grooves formed by the intervals between several rhombus structures form a nested hexagonal grid structure, so that the grout in the grouting groove 9 forms nested hexagonal structural supports after solidification.

[0061] The shaped part of the load-bearing component, designed in this way, allows the component to have strong load-bearing capacity without being completely hollow, thus enhancing its strength.

[0062] like Figure 2 As shown, the end of the load-bearing component 7 is provided with several grouting holes that communicate with the grouting groove. For example, the first grouting hole 77 and the second grouting hole 78 are connected to the grouting cavity 73. The third grouting hole 79 is connected to the grouting groove 9 between the hollow structures 8.

[0063] The pressure-bearing layer 3 of this invention undergoes two pressure distributions. First, the nested hexagonal grid structure distributes the pressure applied by the existing line, allowing the load-bearing components to bear a portion of the pressure. Second, the pressure-resistant layer formed by the grout in the grouting chamber increases the contact area between the existing line and the load-bearing components, preventing excessive pressure at each point and reducing the risk of damage caused by direct pressure on the geometric support pillars. The geometric support pillars formed by the solidification of the grout in the grouting tank 9 support the pressure-resistant layer and further distribute the pressure, resulting in stronger overall support for the load-bearing components.

[0064] Preferably, the non-grouting end of the load-bearing component 7 and / or the wall of the grouting part 73 are provided with a plurality of overflow holes 76. In the case of grouting, excess grout in the load-bearing component 7 overflows from the overflow holes 76 at the non-grouting end, and the overflowing grout forms a load-bearing column when blocked or overflowing by the load-bearing component 7 at the same node.

[0065] Preferably, the ends of the load-bearing components can be equipped with blocking elements. When multiple load-bearing components are located at the same node, the blocking elements block the gap between the ends of two adjacent load-bearing components, allowing the space formed by the convergence of the ends of multiple load-bearing components to form a columnar space capable of accommodating the grout. Thus, the overflowing grout simultaneously forms a load-bearing column during the grouting process, eliminating the need for secondary pouring and saving steps. The overflow hole also reduces the resistance of the grout entering the grouting cavity, improving the efficiency and speed of grouting and saving grouting time. After grouting is completed, the overflow hole also facilitates air circulation, accelerating the loss of moisture in the grout and shortening the grout's setting time.

[0066] Excess grout within the load-bearing component 7 overflows from the overflow hole 76 on the wall of the grouting section 73, and the overflowing grout connects the load-bearing component 7 to the existing line and / or soil layer above it. During grouting, a small gap exists between the load-bearing component and the existing line. Re-installing the grouting pipe would not only waste materials but also make it difficult to insert into the gap. Therefore, the overflow hole 76 on the wall of the grouting section 73 not only reduces grouting resistance but also allows the gap between the load-bearing component and the existing line to be filled with grout, eliminating the need for secondary pouring by construction personnel, saving procedures and time, reducing the use of grouting pipes, and lowering economic costs.

[0067] like Figure 6 As shown, if there is a large gap between the load-bearing component and the existing line during the grouting process, a second concrete layer 4 can be set in the gap.

[0068] Preferably, such as Figure 6 As shown, during construction, at least one concrete layer can be pre-installed, and load-bearing components can be installed on the concrete layer. For example, load-bearing components can be installed on the first concrete layer 2, and several load-bearing components can be connected as a whole. Among them, the load-bearing components 7 are connected to the concrete layer by grouting. The concrete layer is set at the horizontal position at the top of the tunnel.

[0069] Preferably, the bottom of the grouting groove 9 is provided with at least one overflow hole 76. During grouting, grout overflows from the bottom overflow hole 76 to connect the load-bearing component 7 to the concrete layer. Preferably, the size of the bottom overflow hole is smaller than the size of the top or end overflow holes, allowing a small amount of grout to overflow from the bottom. The bottom of the load-bearing component is in close contact with the concrete layer, forming a small gap, thus allowing less grout to enter. If the overflow hole is large, or the grouting pressure is high, a large amount of grout can easily overflow and arch the load-bearing component, reducing its stability. Therefore, the number and size of the bottom overflow holes should be small to improve the stability of the load-bearing component.

[0070] During the installation of the pressure layer, the settlement of the existing railway line is monitored using a settlement monitoring system. Small-sized guide tunnels are installed in stages to install the pressure layer, provided that the existing line is not affected by settlement. Once the pressure layer is installed in a localized area, and if the height of the pressure layer does not deform within a preset period, part of the support device can be removed, allowing the localized pressure layer to support the existing railway line while the settlement of the existing line is monitored.

[0071] Preferably, after the bearing layer is installed, a robustness test can be performed on the bearing layer. If the test is passed, the bearing layer can then bear the support of the existing line. The grouting structure of the bearing layer of this invention also has the advantage that the height of the load-bearing component in the vertical direction is stable and will not undergo significant deformation due to the solidification of the grout. Furthermore, the bearing capacity of the load-bearing component after grouting is known, eliminating the need for frequent pressure tests by construction personnel. Construction personnel only need to monitor whether the grout in the gap between the bearing layer and the existing line has solidified properly, reducing the failure rate of the bearing layer and improving construction quality.

[0072] With the pressure layer stable, construction is carried out in the designated tunnel area below the pressure layer to build the tunnel.

[0073] It should be noted that the specific embodiments described above are exemplary, and those skilled in the art can devise various solutions inspired by the disclosure of this invention. These solutions all fall within the scope of this invention and its protection. Those skilled in the art should understand that this specification and its accompanying drawings are illustrative and not intended to limit the scope of the claims. The scope of protection of this invention is defined by the claims and their equivalents.

[0074] This specification contains multiple inventive concepts, and the applicant reserves the right to file divisional applications based on each inventive concept. The specification contains multiple inventive concepts, and terms such as "preferredly," "according to a preferred embodiment," or "optionally" indicate that the corresponding paragraph discloses an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept.

Claims

1. A grouting construction method for a tunnel passing close to an existing railway line, characterized in that, The method includes at least: In the case of supporting the existing line, the original soil layer between the pre-designed tunnel and the existing line is removed; At least one load-bearing layer (3) capable of supporting the existing line is provided in the original soil layer area between the tunnel and the existing line; wherein... The load-bearing layer (3) is a hexagonal grid structure nested together by splicing several load-bearing components (7); The load-bearing component (7) is a hollow grouting pile body. The load-bearing component (7) includes at least a grouting part (73) and a shaping part (72). The shaping part (72) includes grouting grooves (9) distributed in a grid. The grouting part (73) is a cavity communicating with the grouting grooves (9). When the horizontal height of the shaping part (72) is lower than the horizontal height of the grouting part (73), the grout in the grouting part (73) fills the grouting grooves (9) based on gravity and forms a geometric support pillar that supports the grouting part (73). Several load-bearing components (7) of equal length are distributed at 60 degrees and / or 120 degrees to each other with the nodes as the center, so that the load-bearing components (7) of equal length form a nested regular hexagonal grid structure.

2. The grouting construction method for tunnels passing close to existing railway lines according to claim 1, characterized in that, Nested hexagonal grid structures include: Several rhomboid grid cells composed of load-bearing components (7) are spliced ​​together to form a nested regular hexagonal grid, so that the force applied to the node by each load-bearing component (7) is canceled and / or dispersed by the adjacent load-bearing components (7).

3. The grouting construction method for tunnels passing close to existing railway lines according to claim 1, characterized in that, The grouting groove (9) of the load-bearing component (7) is constructed by several protruding hollow structures (8) at intervals, so that the grouting groove (9) has a regular geometric grid shape.

4. The grouting construction method for tunnels passing close to existing railway lines according to claim 1, characterized in that, The load-bearing component (7) is disposed on at least one layer of concrete and is integrally grouted with the concrete layer. The concrete layer is located at the top horizontal position of the tunnel.

5. The grouting construction method for tunnels passing close to existing railway lines according to claim 1, characterized in that, The bottom of the grouting tank (9) is provided with at least one overflow hole (76). In the case of grouting, the grout overflows from the bottom overflow hole (76) to connect the load-bearing component (7) to the concrete layer.

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