Soft rock tunnel overexcavation backfilling method

Abstract

The invention discloses a soft rock tunnel overexcavation backfill method, and relates to the technical field of tunnel construction.The soft rock tunnel overexcavation backfill method comprises the steps that a three-dimensional live-action image in a tunnel is scanned; establishing a three-dimensional live-action model according to the three-dimensional live-action image; establishing a digital twin model of the tunnel according to a design drawing; carrying out geometric intersection on the three-dimensional live-action model and the digital twin model to obtain geometric parameters of an overexcavation area; a concrete mold is subjected to 3D printing according to the geometric parameters of the overexcavation area; concrete is poured into the concrete mold, and a backfill body is formed; and the backfill body is backfilled to the overexcavation area. Due to the fact that the formed backfill body is tightly attached to the tunnel wall of the overexcavation area, the backfill precision is effectively improved, the construction quality is improved, the stability and the bearing capacity of the inner wall of the tunnel are enhanced, potential safety hazards are reduced, the concrete backfill work amount can be accurately controlled, the construction cost is reduced, and material waste is avoided.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a method for over-excavation and backfilling in soft rock tunnels. Background Technology

[0002] Soft rock tunnels are tunnels constructed in weak surrounding rock. Due to the low strength, large deformation, and softening properties of soft rock when exposed to water, they present significant challenges to tunnel design, construction, and even the long-term stability of the lining structure. During the excavation of soft rock tunnels, the varying combinations of rock mass structural planes and the exposed excavation face can easily lead to over-excavation. When backfilling over-excavated areas, insufficient backfilling precision results in a larger volume of backfill concrete, increasing construction costs and making it difficult to guarantee backfill quality. This leads to stress concentration in the surrounding rock, affecting its stability and creating safety hazards for future construction and tunnel operation. Summary of the Invention

[0003] The main objective of this invention is to propose a method for over-excavation and backfilling of soft rock tunnels, aiming to solve the technical problems in the prior art where insufficient accuracy of over-excavation and backfilling of soft rock tunnels leads to increased construction costs, difficulty in guaranteeing backfill quality, and potential safety hazards.

[0004] To achieve the above objectives, the soft rock tunnel over-excavation backfilling method proposed in this invention includes the following steps: scanning a three-dimensional real-scene image of the tunnel; establishing a three-dimensional real-scene model based on the three-dimensional real-scene image; establishing a digital twin model of the tunnel based on the design drawings; performing geometric intersection between the three-dimensional real-scene model and the digital twin model to obtain the geometric parameters of the over-excavation area; 3D printing a concrete mold based on the geometric parameters of the over-excavation area; pouring concrete into the concrete mold to form a backfill body; and backfilling the backfill body into the over-excavation area.

[0005] In one embodiment, the step of 3D printing a concrete mold based on the geometric parameters of the over-excavated area includes: establishing a mold model based on the geometric parameters of the over-excavated area; processing the data of the mold model; and printing the processed mold model using a 3D printing device to form the concrete mold.

[0006] In one embodiment, the step of data processing the mold model includes: adding multiple connecting seats inside the mold model; each connecting seat being connected to the inner wall of the mold model; determining splitting positions on the mold model; the splitting positions avoiding each connecting seat; and splitting the mold model into a first mold and a second mold through the splitting positions. The step of using a 3D printing device to print the data-processed mold model to form the concrete mold includes: using a 3D printing device to print the first mold and the second mold respectively; and assembling the first mold and the second mold together to form the concrete mold.

[0007] In one embodiment, the step of pouring concrete into the concrete mold to form a backfill body includes: connecting perforated steel pipes to each of the connecting seats; extending each of the perforated steel pipes into the concrete mold; binding and connecting each of the perforated steel pipes with reinforcing bars to form a reinforcing mesh; pouring concrete into the concrete mold; vibrating the concrete; and placing the concrete mold in a curing chamber for curing to form the backfill body.

[0008] In one embodiment, prior to the step of pouring concrete into the concrete mold, the soft rock tunnel over-excavation backfilling method further includes: applying a release agent to the inside of the concrete mold.

[0009] In one embodiment, the step of backfilling the backfill material into the over-excavated area includes: determining the corresponding position of the backfill material and the over-excavated area; spraying an adhesive onto the surfaces of the over-excavated area and the backfill material; and backfilling the backfill material into the over-excavated area.

[0010] In one embodiment, the step of determining the corresponding position of the backfill body and the over-excavated area includes: marking multiple feature points on the backfill body; marking multiple reference points in the tunnel that correspond one-to-one with the multiple feature points; and aligning each of the feature points of the backfill body with the corresponding reference points.

[0011] In one embodiment, the step of marking multiple reference points corresponding one-to-one with the multiple feature points in the tunnel includes: setting up a laser emitting device in the tunnel; and emitting lasers through the laser emitting device toward the positions of the multiple reference points.

[0012] In one embodiment, the step of scanning the three-dimensional real-scene image inside the tunnel includes: cleaning the surface of the tunnel; and setting up a three-dimensional laser scanner inside the tunnel to scan the three-dimensional real-scene image inside the tunnel to obtain the three-dimensional real-scene image.

[0013] In one embodiment, the step of geometrically intersecting the 3D reality model and the digital twin model to obtain the geometric parameters of the over-excavation area includes: acquiring point cloud data within the tunnel based on the 3D reality image; organizing and registering the point cloud data; using 3D modeling software to establish the 3D reality model based on the organized and registered point cloud data; and geometrically intersecting the 3D reality model and the digital twin model to obtain the geometric parameters of the over-excavation area.

[0014] The proposed method for backfilling over-excavation in soft rock tunnels involves performing a 3D real-scene scan of the tunnel interior. A 3D real-scene model is then created based on the acquired images. This model is geometrically intersected with a digital twin model created from the design drawings. The difference between the two models determines the geometric parameters of the over-excavated area. 3D printing technology is used to fabricate matching concrete molds based on these parameters. Concrete is poured into these molds to form backfill material, whose geometric parameters match those of the over-excavated area. This ensures a tight fit between the backfill material and the tunnel wall, effectively improving backfill accuracy, enhancing construction quality, strengthening the stability and load-bearing capacity of the tunnel wall, reducing safety hazards, precisely controlling the amount of backfill concrete, reducing construction costs, and avoiding material waste. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a flowchart illustrating an embodiment of the soft rock tunnel over-excavation and backfilling method provided by the present invention.

[0017] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0020] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0021] When backfilling in over-excavated areas, insufficient backfilling precision leads to a large volume of backfill concrete, increasing construction costs and making it difficult to guarantee backfill quality. This results in stress concentration in the surrounding rock, affecting its stability and creating safety hazards for future construction and tunnel operation.

[0022] This invention proposes a method for backfilling over-excavation in soft rock tunnels, comprising the following steps:

[0023] S10: Scan the three-dimensional real-scene image inside the tunnel;

[0024] S20: Establish a three-dimensional real-scene model based on the three-dimensional real-scene image;

[0025] S30: Establish a digital twin model of the tunnel based on the design drawings;

[0026] S40: Perform geometric intersection between the three-dimensional real-scene model and the digital twin model to obtain the geometric parameters of the over-excavation area;

[0027] S50: 3D print a concrete mold according to the geometric parameters of the over-excavated area;

[0028] S60: Pour concrete into the concrete mold to form a backfill body;

[0029] S70: Backfill the backfill material into the over-excavated area.

[0030] Please see Figure 1In soft rock tunnel excavation, over-excavation can lead to over-excavated areas. After excavation, a 3D real-scene image scan of the tunnel's excavation is performed. Based on this image, 3D real-scene data is acquired, and a 3D real-scene model is created using 3D modeling software. A digital twin model is then created based on the tunnel's design drawings. By performing a geometric intersection operation between the 3D real-scene model and the digital twin model, the difference between them represents the over-excavated area. This allows for the acquisition of geometric parameters such as the location, volume, and shape of the over-excavated area within the tunnel. Based on these geometric parameters, a concrete mold is manufactured using 3D printing technology. The mold forms a pouring cavity with geometric parameters identical to the over-excavated area and possesses sufficient structural strength to withstand the pressure during concrete pouring and solidification. After the mold is formed, concrete is poured into the cavity. Once solidified, a backfill material with the same geometric parameters as the over-excavated area is formed. Finally, the formed backfill material is removed from the cavity and used to fill the over-excavated area, leveling it.

[0031] The proposed method for backfilling over-excavation in soft rock tunnels involves performing a 3D real-scene scan of the tunnel interior. A 3D real-scene model is then created based on the acquired images. This model is geometrically intersected with a digital twin model created from the design drawings. The difference between the two models determines the geometric parameters of the over-excavated area. 3D printing technology is used to fabricate matching concrete molds based on these parameters. Concrete is poured into these molds to form backfill material, whose geometric parameters match those of the over-excavated area. This ensures a tight fit between the backfill material and the tunnel wall, effectively improving backfill accuracy, enhancing construction quality, strengthening the stability and load-bearing capacity of the tunnel wall, reducing safety hazards, precisely controlling the amount of backfill concrete, reducing construction costs, and avoiding material waste.

[0032] In one embodiment, step S50 includes:

[0033] S51: Establish a mold model based on the geometric parameters of the over-excavation area;

[0034] S52: Perform data processing on the mold model;

[0035] S53: The mold model after data processing is printed using 3D printing equipment to form the concrete mold.

[0036] Understandably, the geometric parameters obtained through geometric intersection are input into 3D modeling software, and a mold model that perfectly matches the over-excavated area is precisely constructed based on these parameters. This mold model serves as the basis for 3D printing, ensuring that the printed mold accurately adapts to the shape and size of the over-excavated area. Data processing of the mold model includes, but is not limited to, slicing the model, adding support structures, and optimizing the printing path to ensure smooth 3D printing and improve printing efficiency and product quality. After data processing, the mold model file is input into the 3D printing equipment, a suitable printing material is selected, and printing proceeds according to the optimized printing path. During printing, the 3D printing equipment builds the mold layer by layer until the entire mold is fully formed, ensuring that the concrete mold produces a backfill body with geometric parameters perfectly consistent with the over-excavated area.

[0037] In one embodiment, step S52 includes:

[0038] S521: Multiple connecting seats are added inside the mold model; each connecting seat is connected to the inner wall of the mold model;

[0039] S522: Determine the splitting position on the mold model; the splitting position avoids each of the connecting seats;

[0040] S523: The mold model is split into a first mold and a second mold at the splitting position.

[0041] Step S53 includes:

[0042] S531: Use 3D printing equipment to print the first mold and the second mold respectively;

[0043] S532: The first mold and the second mold are joined together to form the concrete mold.

[0044] To illustrate, the data processing steps for the mold model include setting connectors and determining splitting positions on the mold model in the 3D printing software, so as to print and form a concrete mold based on the mold model. The connectors are connected to the inner wall of the concrete mold and extend inward. The connectors provide connection positions for the porous steel pipes, ensuring that each porous steel pipe in the backfill body is firmly connected to the concrete mold. The concrete mold can be split into a first mold and a second mold from the splitting position, which facilitates the assembly and disassembly of the concrete mold, thereby facilitating the pouring and demolding of the backfill body.

[0045] In one embodiment, step S60 includes:

[0046] S61: A perforated steel pipe is connected to each of the connecting seats; each of the perforated steel pipes extends into the concrete mold.

[0047] S62: Use steel bars to tie and connect the porous steel pipes to form a steel mesh;

[0048] S63: Pour concrete into the concrete mold;

[0049] S64: Vibrating concrete;

[0050] S65: The concrete mold is placed in a curing room for curing to form the backfill body.

[0051] It should be noted that by adding multiple perforated steel pipes inside the concrete mold, and binding the pipes together with reinforcing bars to form a reinforcing mesh on the side facing inward, the concrete and the perforated steel pipes are poured together to form the backfill, effectively improving the tensile strength and structural stability of the backfill. During concrete pouring, thorough vibration ensures that the concrete enters the perforated steel pipes through the holes, ensuring dense filling and tight bonding, thus guaranteeing the structural strength of the backfill. When the backfill is removed from the concrete mold, each perforated steel pipe is also removed from its corresponding connecting seat.

[0052] In one embodiment, prior to step S63, the soft rock tunnel over-excavation backfilling method further includes:

[0053] S629: Apply a release agent to the inside of the concrete mold.

[0054] Understandably, by applying a release agent to the inside of the concrete mold, the adhesion between the backfill and the concrete mold can be significantly reduced, making it easier and more complete for the backfill to be removed from the concrete mold after hardening. This reduces surface damage to the backfill caused by difficulties in demolding and ensures the integrity and geometric accuracy of the backfill.

[0055] In one embodiment, step S70 includes:

[0056] S71: Determine the corresponding position of the backfill body and the over-excavated area;

[0057] S72: Spray adhesive onto the surfaces of the over-excavated area and the backfill;

[0058] S73: Backfill the backfill material into the over-excavated area.

[0059] It can be explained that, due to the geometric parameters of each backfill body corresponding to each over-excavated area, when facing multiple backfill bodies and multiple over-excavated areas, it is necessary to first determine the corresponding positional relationship between the backfill body and the over-excavated area before backfilling the corresponding over-excavated area, ensuring that the backfill body is backfilled at a mutually matching angle and position. By spraying a layer of adhesive on the inner wall of the over-excavated area and the outer surface of the backfill body respectively, a long-term stable bond between the backfill body and the tunnel wall of the over-excavated area is ensured, ensuring accurate and stable backfilling.

[0060] In one embodiment, step S71 includes:

[0061] S711: Mark multiple feature points on the backfill body;

[0062] S712: Mark multiple reference points within the tunnel that correspond one-to-one with the multiple feature points;

[0063] S713: Align each of the feature points of the backfill body with the corresponding control points.

[0064] Furthermore, by identifying multiple feature points on the backfill body and corresponding reference points in the over-excavated area, the backfill direction and angle of the backfill body are precisely aligned with the over-excavated area, thus ensuring accurate backfilling. It should be noted that, to improve the positioning effect, when identifying multiple feature points on the backfill body, these feature points are not coplanar and are as far apart as possible.

[0065] In one embodiment, step S712 includes:

[0066] S7121: A laser emitting device is installed inside the tunnel;

[0067] S7122: The laser is emitted by the laser emitting device toward the positions of the plurality of reference points.

[0068] It should be noted that the laser emitting device is connected to an external processor. After the external processor obtains the location of the reference points in the over-excavated area, the laser emitting device can emit lasers to the location of each reference point to mark the location of the over-excavated area in the complex environment inside the tunnel. This facilitates the construction personnel to accurately locate the over-excavated area, reduce construction errors, and ensure that the backfill and the over-excavated area are accurately aligned.

[0069] In one embodiment, step S10 includes:

[0070] S11: Clean the surface of the tunnel;

[0071] S12: A 3D laser scanner is installed inside the tunnel to scan the 3D real-world image inside the tunnel in order to obtain the 3D real-world image.

[0072] Understandably, after tunnel excavation, necessary cleaning of the tunnel surface is essential to ensure the cleanliness and safety of the tunnel interior, reduce errors during the scanning process, and ensure more accurate 3D reality images, providing high-quality foundational data for subsequent data analysis and processing. Installing a 3D laser scanner inside the tunnel allows for precise 3D scanning of the tunnel's interior space, generating 3D reality images of the tunnel. The 3D laser scanner enables rapid, real-time scanning, reducing the time and labor required by traditional measurement methods and improving construction efficiency.

[0073] In one embodiment, step S40 includes:

[0074] S41: Obtain point cloud data within the tunnel based on the three-dimensional real-scene image;

[0075] S42: Organize and register the point cloud data;

[0076] S43: Use 3D modeling software to build the 3D reality model based on the organized and registered point cloud data;

[0077] S44: Perform geometric intersection between the 3D reality model and the data twin model to obtain the geometric parameters of the over-excavation area.

[0078] Furthermore, point cloud data within the tunnel is acquired using a 3D laser scanner. This point cloud data contains the spatial coordinates of various points within the tunnel. The point cloud data is then processed through outlier removal, smoothing, data alignment, and correction to organize and register it. A 3D reality model is then built based on this organized and registered data, ensuring that the model closely matches the actual excavation conditions within the tunnel. An accurate 3D reality model can more realistically reflect the actual conditions inside the tunnel. Finally, the established 3D reality model is geometrically intersected with the tunnel's digital twin model to obtain the geometric parameters of the over-excavated area. This provides a precise basis for subsequent construction decisions, optimizes construction plans, and reduces material waste and additional construction costs.

[0079] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for over-excavation and backfilling of soft rock tunnels, characterized in that, Including the following steps: Scan the three-dimensional real-world images inside the tunnel; A three-dimensional real-scene model is established based on the three-dimensional real-scene image; A digital twin model of the tunnel was created based on the design drawings; The geometric intersection of the three-dimensional real-scene model and the digital twin model is performed to obtain the geometric parameters of the over-excavation area; 3D print concrete molds based on the geometric parameters of the over-excavated area; Concrete is poured into the concrete mold to form the backfill body; The backfill material is then backfilled into the over-excavated area.

2. The method for over-excavation and backfilling of soft rock tunnels as described in claim 1, characterized in that, The step of 3D printing concrete molds based on the geometric parameters of the over-excavated area includes: A mold model is established based on the geometric parameters of the over-excavation area; Data processing is performed on the mold model; The data-processed mold model is printed using 3D printing equipment to form the concrete mold.

3. The method for over-excavation and backfilling of soft rock tunnels as described in claim 2, characterized in that, The steps for data processing of the mold model include: Multiple connecting seats are added inside the mold model; each connecting seat is connected to the inner wall of the mold model. The splitting points are determined on the mold model; the splitting points avoid each of the connecting seats. The mold model is split into a first mold and a second mold at the splitting point; The step of using 3D printing equipment to print the data-processed mold model to form the concrete mold includes: The first mold and the second mold were printed using 3D printing equipment, respectively. The first mold and the second mold are joined together to form the concrete mold.

4. The method for over-excavation and backfilling of soft rock tunnels as described in claim 3, characterized in that, The step of pouring concrete into the concrete mold to form the backfill body includes: A perforated steel pipe is connected to each of the aforementioned connecting seats; each of the aforementioned perforated steel pipes extends into the concrete mold. The porous steel pipes are tied together with steel bars to form a steel mesh. Concrete is poured into the concrete mold; Vibrate the concrete; The concrete mold is placed in a curing room for curing to form the backfill body.

5. The method for over-excavation and backfilling of soft rock tunnels as described in claim 4, characterized in that, Prior to the step of pouring concrete into the concrete mold, the soft rock tunnel over-excavation backfilling method further includes: Apply a release agent to the inside of the concrete mold.

6. The method for over-excavation and backfilling of soft rock tunnels as described in any one of claims 1 to 5, characterized in that, The step of backfilling the backfill material into the over-excavated area includes: Determine the corresponding positions of the backfill and the over-excavated area; Adhesive is sprayed onto the surfaces of the over-excavated area and the backfill. The backfill material is then backfilled into the over-excavated area.

7. The method for over-excavation and backfilling of soft rock tunnels as described in claim 6, characterized in that, The step of determining the corresponding position of the backfill body and the over-excavated area includes: Multiple feature points were marked on the backfill body; Mark multiple reference points within the tunnel that correspond one-to-one with the multiple feature points; Align each of the feature points of the backfill body with the corresponding control points.

8. The method for over-excavation and backfilling of soft rock tunnels as described in claim 7, characterized in that, The step of marking multiple reference points within the tunnel that correspond one-to-one with the multiple feature points includes: A laser emitting device was installed inside the tunnel; The laser emitting device emits lasers toward the locations of the multiple reference points.

9. The method for over-excavation and backfilling of soft rock tunnels as described in any one of claims 1 to 5, characterized in that, The step of scanning the three-dimensional real-scene image inside the tunnel includes: The surface of the tunnel is cleaned; A 3D laser scanner is installed inside the tunnel to scan the 3D real-world image inside the tunnel in order to obtain a 3D real-world image.

10. The method for over-excavation and backfilling of soft rock tunnels as described in claim 9, characterized in that, The step of performing geometric intersection between the 3D reality model and the digital twin model to obtain the geometric parameters of the over-excavation area includes: The point cloud data inside the tunnel is obtained based on the three-dimensional real-scene image; The point cloud data is organized and registered; The three-dimensional reality model is created using 3D modeling software based on the organized and registered point cloud data. The geometric intersection of the 3D reality model and the data twin model is performed to obtain the geometric parameters of the over-excavation area.

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