A tunnel multi-process parallel construction method based on an advanced small pilot hole

Abstract

The application discloses a tunnel multi-process parallel construction method based on a small pilot hole, and aims at the problems of low efficiency and long construction period caused by the series connection of existing tunnel construction processes, wherein a small pilot hole is extended along the extension track of the main tunnel on the side of the main tunnel, geological detection is further performed on the surrounding rock of the main tunnel during the construction of the small pilot hole, the advance support process of each region of the main tunnel is determined according to the detection result, the advance support construction of the main tunnel is performed with the aid of the small pilot hole, and the excavation, primary support and secondary lining processes are sequentially and circularly performed in the main tunnel, so that the multi-process space parallel construction is realized. The method can greatly improve the construction organization efficiency, shorten the construction period, improve the adaptability to complex geology and the construction safety, and the small pilot hole can be used as a permanent auxiliary structure, thereby improving the resource utilization rate.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering construction technology, specifically relating to a method for parallel construction of multiple processes in tunnels based on advanced pilot tunnels. Background Technology

[0002] With the rapid development of railway, highway, municipal, and underground integrated transportation engineering, the number of ultra-long tunnels, large-section tunnels, and tunnels under complex geological conditions continues to increase. This places more stringent demands on construction efficiency, safety, and schedule control. Currently, mainstream tunnel construction methods such as the mining method and the New Austrian Tunneling Method (NATM) generally adopt a cyclical construction model of "advance support—excavation—initial support—secondary lining." There is a strict sequential dependency between each construction procedure; subsequent procedures can only be carried out after the previous one is completed, making it difficult to achieve parallel operation of multiple procedures.

[0003] Under the aforementioned construction model, all procedures are carried out around the same tunnel face, and different procedures can only be advanced sequentially. This results in a long construction cycle, low utilization of construction equipment and personnel, and limited overall construction efficiency. Especially in ultra-long tunnels, weak surrounding rock, and complex geological conditions, the overall project duration is difficult to control effectively. On the other hand, the geological conditions ahead are mainly obtained through advanced geological forecasting and advanced drilling. However, the detection results have certain limitations. When the actual geological conditions revealed at the tunnel face change, the construction unit often needs to temporarily adjust the advanced support and excavation plans, which seriously affects the efficiency of construction organization and may even lead to construction safety risks.

[0004] Furthermore, pilot tunnels in existing tunnel construction are mostly used as auxiliary construction measures, only serving to assist the main tunnel construction. After completion, they are usually abandoned or closed, failing to fully realize their subsequent use value and resulting in a waste of underground space resources. Therefore, how to break through the current sequential organization mode of tunnel construction procedures, achieve synchronous construction of different procedures, improve the efficiency of construction organization under complex geological conditions, and fully explore the engineering value of pilot tunnels are urgent technical problems that need to be solved in the current tunnel construction field. Summary of the Invention

[0005] To address one of the aforementioned technical problems, this invention provides a method for parallel construction of multiple tunnel processes based on advanced pilot tunnels.

[0006] This application provides the following technical solution: A method for parallel multi-stage tunnel construction based on advanced pilot tunnels includes: Small pilot tunnels are constructed around the main tunnel, extending along the trajectory of the main tunnel. During the construction of the pilot tunnel, geological surveys were conducted on the surrounding rock of the main tunnel. The advanced support technology for each area of ​​the main tunnel was determined based on the geological survey results. The main tunnel was constructed using a pilot tunnel; The excavation, initial support, and secondary lining processes are carried out sequentially and cyclically within the main tunnel.

[0007] Optionally, at least one small pilot tunnel may be constructed around the main tunnel.

[0008] Optionally, two small pilot tunnels are located on both sides of the main tunnel; construction work is carried out simultaneously in the two small pilot tunnels.

[0009] Alternatively, two small pilot tunnels are located on either side of the arch area of ​​the main tunnel; The distance between the small pilot tunnel and the main tunnel is 1m to 2m.

[0010] Optionally, the ratio of the main tunnel span to the pilot tunnel diameter is greater than 4, and the main tunnel span is not less than 8m; The diameter of the small pilot tunnel is 2m to 2.5m.

[0011] Optionally, the geological exploration of the surrounding rock of the main tunnel during the construction of the pilot tunnel includes: revealing and determining the information of the surrounding rock ahead in real time by observing the slag discharge status, water outflow status at the tunnel face, tunneling resistance, and changes in tunneling posture during the construction of the pilot tunnel. The surrounding rock information includes the properties of the surrounding rock itself, groundwater hydrological information, and information on the distribution of adverse geological bodies.

[0012] Optionally, determining the advanced support technology for each area of ​​the main tunnel based on geological survey results includes: determining the corresponding advanced support technology and parameters for each extension section based on the surrounding rock information of different extension sections of the main tunnel.

[0013] Optionally, the advanced support construction of the main tunnel using a small pilot tunnel includes: laying out long strip support bodies extending toward the main tunnel in the pilot tunnel, with each long strip support body arranged sequentially along the longitudinal direction of the main tunnel, and each long strip support body cooperating with each other and arranged around the circumference of the main tunnel to form an overall advanced support structure covering the outer perimeter of the main tunnel excavation outline.

[0014] Optionally, advance support construction of the main tunnel can be completed by using small pilot tunnels located around the main tunnel. Long strip support structures extending toward the main tunnel are installed in each pilot tunnel. At least some pilot tunnels are equipped with long strip support structures extending to the outside of the main tunnel arch. The long strip support structures installed in different pilot tunnels and distributed on the outside of the main tunnel arch are arranged opposite to or staggered, eventually forming a complete advance support structure at the top of the main tunnel.

[0015] Optionally, a top-shield integrated machine can be used for the construction of small pilot tunnels. The small pilot tunnel is first constructed in the jacking mode, and after the construction is set, it is switched to the shield mode to construct the small pilot tunnel. The set distance is 300m to 500m.

[0016] Optionally, during the construction of the pilot tunnel using the jacking method, the advance support process, excavation process, initial support process and secondary lining process are sequentially and cyclically performed in the main tunnel. During the construction of the pilot tunnel using the shield tunneling method, the excavation process, initial support process and secondary lining process are sequentially and cyclically performed in the main tunnel.

[0017] Optionally, the pilot tunnel is always positioned ahead of the main tunnel face by a predetermined distance; The set distance is not less than 50m.

[0018] By adopting the above technical solution, this application has the following beneficial effects: This application addresses the problems of existing tunnel construction processes being sequential, inefficient, and time-consuming. It proposes constructing a small pilot tunnel extending along the main tunnel's trajectory around its perimeter. During the construction of the pilot tunnel, geological surveys are conducted on the surrounding rock of the main tunnel. Based on the survey results, the advanced support technology for each area of ​​the main tunnel is determined. Advanced support construction of the main tunnel is then carried out using the pilot tunnel. Simultaneously, excavation, initial support, and secondary lining are sequentially and cyclically executed within the main tunnel, enabling parallel construction of multiple processes in space. This method significantly improves construction organization efficiency, shortens the construction period, enhances adaptability to complex geological conditions and construction safety, and the pilot tunnel can be utilized as a permanent auxiliary structure, improving resource utilization. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0020] Figure 1 A schematic diagram showing the pre-support construction of the main tunnel using a small pilot tunnel is shown. Figure 2 This diagram illustrates the parallel construction of multiple processes in a tunnel based on a small pilot tunnel.

[0021] In the diagram: 1. Main tunnel; 2. Pilot tunnel; 3. Long strip support structure; 4. Top shield integrated machine. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0023] In the description of this invention, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] like Figure 1 and Figure 2 As shown, this application provides a method for parallel construction of multiple tunnel processes based on a small pilot tunnel 2, including: A small pilot tunnel 2 is constructed around the main tunnel 1, extending along the extension trajectory of the main tunnel 1. During the construction of the pilot tunnel 2, further geological exploration was conducted on the surrounding rock of the main tunnel. The advanced support technology for each area of ​​the main tunnel 1 was determined based on the geological survey results. The pilot tunnel 2 was used to carry out advance support construction on the main tunnel 1; The excavation, initial support, and secondary lining processes are carried out sequentially and cyclically within the main tunnel 1.

[0026] In this application, the pilot tunnel extends synchronously along the trajectory of the main tunnel 1, ensuring that it runs through the entire construction process of the main tunnel 1, providing a stable working platform for subsequent advanced support and geological exploration; secondly, during the construction of the pilot tunnel, geological exploration of the surrounding rock is carried out simultaneously, without occupying additional construction time of the main tunnel 1, enabling real-time acquisition of geological information; thirdly, based on the obtained surrounding rock information, the advanced support technology for each area of ​​the main tunnel 1 is determined in a targeted manner, avoiding blind support schemes; fourthly, the independent space of the pilot tunnel 2 is used to carry out advanced support construction of the main tunnel 1, overcoming the spatial limitations of the tunnel face; fifthly, while the advanced support construction is underway, the excavation, initial support, and secondary lining processes are sequentially and cyclically executed within the main tunnel 1, so that the advanced support is simultaneously advanced with the excavation, initial support, and secondary lining processes of the main tunnel 1 in different spatial locations, forming a continuous multi-process parallel construction system, which greatly improves construction efficiency.

[0027] In some possible implementations, at least one small pilot tunnel is constructed around the perimeter of the main tunnel, with the pilot tunnels spaced apart sequentially along the circumference of the main tunnel 1. When the span of the main tunnel is small, one or two pilot tunnels may be constructed; when the span of the main tunnel is large, three or more pilot tunnels may be constructed.

[0028] In some possible implementations, two small pilot tunnels 2 can be constructed around the main tunnel 1, with the two small pilot tunnels 2 symmetrically distributed on both sides of the main tunnel 1, and construction work carried out simultaneously in the two small pilot tunnels 2.

[0029] In this implementation plan, two small pilot tunnels 2 can be constructed around the main tunnel 1. These two pilot tunnels are symmetrically distributed on both sides of the main tunnel 1. This symmetrical arrangement ensures balanced stress distribution on the main tunnel 1, avoiding stress imbalance in the surrounding rock caused by unilateral construction. Simultaneous construction within the two pilot tunnels 2 further improves the efficiency of advanced support construction, shortens the time required for advanced support procedures, and provides more ample working space and time for the excavation of the main tunnel 1 and subsequent procedures. This is particularly suitable for large-section tunnels or engineering scenarios with complex geological conditions and high demands for advanced support. Simultaneous operation of the two pilot tunnels also allows for cross-verification of geological exploration information, improving the accuracy of geological assessments.

[0030] In some possible implementations, the two small pilot tunnels 2 are distributed on both sides of the main tunnel 1, such as on both sides of the arch area of ​​the main tunnel 1, and the distance between the small pilot tunnels 2 and the main tunnel 1 can be 1m to 2m.

[0031] The two small pilot tunnels 2 are preferably arranged on both sides of the main tunnel 1. This location can effectively cover the arch crown and key stress areas on both sides of the main tunnel 1, facilitating the formation of a complete top protection structure for the subsequent advanced support system and reducing the risk of instability of the surrounding rock at the arch crown during the construction of the small pilot tunnels of the main tunnel 1. The distance between the small pilot tunnels 2 and the main tunnel 1 can be set to 1m to 2m. This spacing ensures that the construction and support work of the small pilot tunnels do not affect the normal construction of the main tunnel 1, and also ensures that the advanced support system can effectively extend to the outer perimeter of the excavation outline of the main tunnel 1 to form a reliable support system. The specific parameter values ​​can be flexibly adjusted according to the actual engineering geological conditions and construction requirements.

[0032] In some possible implementations, the ratio of the main tunnel span to the pilot tunnel diameter is greater than 4, and the main tunnel span is not less than 8m, wherein the pilot tunnel diameter is 2m to 2.5m.

[0033] In some possible implementation schemes, during the construction of the pilot tunnel 2, geological exploration of the surrounding rock around the main tunnel includes: revealing and determining the surrounding rock information in real time by observing the slag discharge status, water outflow status at the tunnel face, tunneling resistance, and changes in tunneling posture during the excavation of the pilot tunnel 2. The surrounding rock information includes the properties of the surrounding rock body, groundwater hydrological information, and distribution information of adverse geological bodies.

[0034] Geological exploration during the construction of the pilot tunnel can be achieved by deploying dedicated detection equipment or by real-time monitoring of various parameters and site conditions during the tunnel's excavation. Specifically, this includes: observing the particle size, shape, and color of the excavated material to determine the hardness and integrity of the surrounding rock; monitoring the flow rate, pressure, and turbidity of water exiting the tunnel face to understand the groundwater hydrology; and recording changes in tunneling resistance and speed, combined with deviations and fluctuations in the tunneling posture, to indirectly determine the stability and geological anomalies of the surrounding rock ahead. Through comprehensive analysis of this multi-dimensional information, the geological properties of the surrounding rock (such as rock grade and integrity coefficient), groundwater hydrological information (such as water level, volume, and permeability), and the distribution and scale of adverse geological bodies (such as faults, fracture zones, and karst caves) can be revealed and determined in real time, providing a precise basis for subsequent adjustments to the support scheme.

[0035] In some possible implementation schemes, determining the advanced support technology for each area of ​​the main tunnel 1 based on geological survey results includes: determining the corresponding advanced support technology and parameters for each extension section based on the surrounding rock information of different extension sections of the main tunnel 1, wherein the advanced support technology is selected from one or more combinations of advanced anchor bolts, advanced grouting, and advanced pipe roof.

[0036] Based on the surrounding rock information of different extension sections of the main tunnel 1 obtained from geological surveys, targeted advanced support technologies and parameters for each extension section can be determined, enabling dynamic optimization of the support scheme. Specifically, for sections with good surrounding rock integrity and high stability, a single advanced anchor bolt can be selected as the support technology, simplifying the construction process and reducing costs. For sections with fractured surrounding rock and abundant groundwater, a combination of advanced grouting and advanced anchor bolts can be used to reinforce the surrounding rock and improve its stability. For complex geological sections such as weak surrounding rock and fault fracture zones, a combination of advanced pipe roof, advanced grouting, and advanced anchor bolts can be used to form multiple support and protection measures, ensuring construction safety. The parameters of the advanced support technology (such as anchor bolt length, grouting pressure, and pipe roof spacing) need to be precisely set based on factors such as the surrounding rock grade and excavation progress of each section to ensure a balance between support effectiveness and construction efficiency.

[0037] In some possible implementation schemes, the advanced support construction of the main tunnel 1 using the pilot tunnel 2 includes: laying out long strip support bodies 3 extending toward the main tunnel 1 in the pilot tunnel, with each long strip support body 3 arranged sequentially along the longitudinal direction of the main tunnel 1, and each long strip support body 3 cooperating with each other and arranged around the main tunnel 1 in a circumferential manner to form an overall advanced support structure covering the outer perimeter of the excavation outline of the main tunnel 1.

[0038] Existing technology involves construction within the main tunnel 1, with elongated support structures 3 extending along the length of the main tunnel 1. This application, however, utilizes small pilot tunnels 2 around the main tunnel 1 for advanced support construction. Due to spatial limitations of the pilot tunnels, elongated support structures 3 extending along the circumference of the main tunnel 1 are constructed. Specifically, within the pilot tunnels 2, elongated support structures 3 extending towards the main tunnel 1 are arranged. Each elongated support structure 3 extends along the circumference of the main tunnel 1, and multiple elongated support structures 3 are arranged sequentially at intervals along the length of the main tunnel 1. The spacing can be determined based on the surrounding rock grade and support requirements. These elongated support structures 3 cooperate with each other and are arranged around the circumference of the main tunnel 1, ultimately forming an overall advanced support structure covering the outer perimeter of the main tunnel 1 excavation outline. This support structure can reinforce the surrounding rock in the excavation area of ​​the main tunnel 1 in advance, so that the excavation of the main tunnel 1 can always be carried out in the area where the advance support has been completed, effectively reducing the risks of surrounding rock instability and surface subsidence. At the same time, the layout of the long strip support body 3 can make full use of the independent space of the small pilot tunnel, avoid mutual interference between the support operation and the construction of the main tunnel 1, and improve the continuity of construction.

[0039] In some possible implementation schemes, the advance support construction of the main tunnel 1 is completed by means of small pilot tunnels 2 located around the main tunnel 1; long strip support bodies 3 extending toward the main tunnel 1 are respectively arranged in each small pilot tunnel 2 (at least one), and at least some of the small pilot tunnels 2 are arranged with long strip support bodies 3 extending to the outside of the main tunnel arch. The long strip support bodies 3 arranged in different small pilot tunnels 2 and distributed on the outside of the main tunnel arch are arranged opposite or staggered, and finally a complete advance support body is formed at the top of the main tunnel 1.

[0040] Optionally, the individual pre-support bodies can be grouted and consolidated to form a connected whole, ultimately forming a complete and closed pre-support structure at the top of the main tunnel 1.

[0041] like Figure 1 As shown, taking the example of setting up a small pilot tunnel 2 on both sides of the main tunnel 1, the following explanation is given: Long strip support bodies 3 extending towards the main tunnel 1 are respectively arranged in the small pilot tunnels 2 on both sides. Long strip support bodies 3 extending to the outer side of the arch of the main tunnel 1 are arranged in both small pilot tunnels 2. The long strip support bodies 3 arranged on the outer side of the arch of the main tunnel 1 on both sides of the small pilot tunnels 2 are arranged opposite or staggered, and are connected as a whole by grouting and consolidation, and finally a complete and closed advanced support structure is formed at the top of the main tunnel 1.

[0042] When both sides of the main tunnel 1 are equipped with small pilot tunnels 2, the advanced support construction of the main tunnel 1 can be completed through the coordinated operation of the two pilot tunnels. Long strip support bodies 3 extending towards the main tunnel 1 are respectively arranged in the small pilot tunnels 2 on both sides. The long strip support bodies 3 extending to the outer side of the arch of the main tunnel 1 are arranged in both small pilot tunnels. The long strip support bodies 3 arranged on the outer side of the arch of the small pilot tunnels on both sides can be arranged in a relatively opposite or staggered manner. The support bodies on both sides are connected into a whole by grouting consolidation technology to form a closed arch advanced support structure. At the same time, support bodies facing the sides and bottom of the main tunnel 1 can also be arranged in the small pilot tunnels on both sides, which, together with the arch support structure, form a comprehensive advanced support system for the main tunnel 1, further improving the reliability of support under complex geological conditions.

[0043] In some possible implementation schemes, a top-shield integrated machine 4 is used to construct the small pilot tunnel 2. The small pilot tunnel 2 is first constructed in the jacking mode, and after a set distance is reached, the machine is switched to the shield mode to construct the small pilot tunnel 2. The set distance is 300m to 500m.

[0044] In this implementation plan, the pilot tunnel 2 is constructed using a top-shield integrated machine 4, combining the advantages of both the jacking and shield tunneling modes to improve the construction efficiency and stability of the pilot tunnel. In the initial construction phase (e.g., within the range of 0-300m or 0-500m), the jacking mode is used. This mode eliminates the need for a tunneling head at the front, using the main jacks at the working shaft to provide power and push the tunnel sections into the ground segment by segment. This mode is suitable for short distances and relatively simple geological conditions, resulting in lower construction costs. When the construction distance reaches 300m-500m, the system switches to shield tunneling mode. At this point, the shield tunneling head is at the forefront, the front of the shield body completes soil excavation or breaking, and the rear simultaneously installs tunnel sections, steel structures, and other support structures, forming a stable small-section underground space. The reason for switching modes is that the power source of the jacking mode is located in the working shaft. Long-distance jacking requires the setting of multiple relay rooms, which slows down the construction speed. In addition, the pipe sections are rigidly linked as a whole during the jacking process, making it impossible to carry out drilling, grouting and other operations on the already jacked sections. In contrast, the shield tunneling mode can realize the simultaneous excavation and support, and can stably carry out subsequent reinforcement operations on the already constructed sections, avoiding the extension of the construction period caused by the sequential execution of procedures.

[0045] In some possible implementation schemes, during the construction of the pilot tunnel 2 using the jacking method, the advance support process, excavation process, initial support process and secondary lining process are sequentially and cyclically performed in the main tunnel 1.

[0046] The pilot tunnel 2 is constructed using a combination of jacking and shield tunneling. The coordination of construction processes in the main tunnel 1 differs depending on the mode: When using jacking mode, the main tunnel 1 sequentially executes the advance support, excavation, initial support, and secondary lining processes; when switching to shield tunneling mode, the main tunnel 1 sequentially executes the excavation, initial support, and secondary lining processes. The reason for using a jacking mode followed by shield tunneling is that jacking mode allows for rapid advancement of the pilot tunnel in the initial stages. Simultaneously, by analyzing various parameters and site conditions during the excavation process, the rock strata ahead can be preliminarily assessed. Once geological safety and construction conditions are confirmed, the shield tunneling mode is then used for long-distance construction. This approach avoids the geological risks associated with long-distance shield tunneling while leveraging the advantages of simultaneous excavation and support in shield tunneling, improving overall construction efficiency and safety.

[0047] In some possible implementation schemes, the pilot tunnel 2 is always kept ahead of the working face of the main tunnel 1 by a set distance of not less than 50m.

[0048] During construction, the pilot tunnel 2 must always be positioned ahead of the main tunnel 1 face by a predetermined distance. This predetermined distance should be no less than 50 meters, and the specific value can be flexibly adjusted based on factors such as the length of the main tunnel 1, geological conditions, and construction progress. Maintaining the pilot tunnel's advance position ensures that the advance support construction always precedes the excavation of the main tunnel 1, providing sufficient preparation time for each stage of the main tunnel 1's construction. It also allows for continuous early exposure of geological information ahead, facilitating timely adjustments to the construction plan and mitigating risks associated with sudden geological changes. For ultra-long tunnels or complex geological sections, the advance distance can be appropriately increased to ensure sufficient time for geological exploration and support adjustments; for short tunnels or sections with favorable geological conditions, the advance distance can be appropriately decreased to improve construction efficiency.

[0049] In addition, this application also provides another construction mode: when the stratum conditions are good and the geological stability is high, the entire shield tunneling mode can be used directly without first using the jacking mode, which further simplifies the construction process; among them, the 30m range behind the shield tail is the transition section, and beyond 30m the tunnel body is completely stationary, and a dedicated reinforcement safety operation zone can be delineated. The advanced support construction of the main tunnel can be carried out in this safety operation zone, which not only ensures the safety of the support operation, but also enables the parallel advancement of the small pilot tunnel construction and the advanced support of the main tunnel.

[0050] The preferred embodiments disclosed above are merely illustrative of this application. The preferred embodiments do not exhaustively describe modifications and variations. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize this application. This application is limited only by the claims and their full scope and equivalents.

Claims

1. A method for parallel multi-stage tunnel construction based on advanced pilot tunnels, characterized in that, include: Small pilot tunnels are constructed around the main tunnel, extending along the trajectory of the main tunnel. During the construction of the pilot tunnel, geological surveys were conducted on the surrounding rock of the main tunnel. The advanced support technology for each area of ​​the main tunnel was determined based on the geological survey results. The main tunnel was constructed using a pilot tunnel; The excavation, initial support, and secondary lining processes are carried out sequentially and cyclically within the main tunnel.

2. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 1, characterized in that, At least one small pilot tunnel shall be constructed around the main tunnel.

3. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 1, characterized in that, Two smaller pilot tunnels are located on both sides of the main tunnel; construction work is carried out simultaneously in the two smaller pilot tunnels.

4. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 3, characterized in that, Two small pilot tunnels are located on either side of the arch area of ​​the main tunnel; The distance between the small pilot tunnel and the main tunnel is 1m to 2m.

5. The method for parallel construction of tunnels using advanced pilot tunnels according to any one of claims 1-4, characterized in that, The ratio of the main tunnel span to the pilot tunnel diameter is greater than 4, and the main tunnel span is not less than 8m; The diameter of the small pilot tunnel is 2m to 2.5m.

6. The method for parallel construction of multiple tunnel processes based on advance pilot tunnels according to any one of claims 1-4, characterized in that, The geological exploration of the surrounding rock of the main tunnel during the construction of the pilot tunnel includes: revealing and determining the information of the surrounding rock ahead in real time by observing the slag discharge status, water outflow status at the tunnel face, tunneling resistance, and changes in tunneling posture during the construction of the pilot tunnel. The surrounding rock information includes the properties of the surrounding rock itself, groundwater hydrological information, and information on the distribution of adverse geological bodies.

7. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 6, characterized in that, The determination of the advanced support technology for each area of ​​the main tunnel based on geological exploration results includes: determining the corresponding advanced support technology and parameters for each extension section based on the surrounding rock information of different extension sections of the main tunnel.

8. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 7, characterized in that, The construction of advanced support for the main tunnel using a pilot tunnel includes: laying out long strip support bodies extending toward the main tunnel in the pilot tunnel. Each long strip support body is set up sequentially along the longitudinal direction of the main tunnel, and the long strip support bodies cooperate with each other and are arranged around the circumference of the main tunnel to form an overall advanced support structure covering the outer perimeter of the main tunnel excavation outline.

9. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 1, characterized in that, The advance support construction of the main tunnel is completed by using small pilot tunnels located around the main tunnel. Long strip support structures extending toward the main tunnel are installed in each pilot tunnel. At least some pilot tunnels are equipped with long strip support structures extending to the outside of the main tunnel arch. The long strip support structures installed in different pilot tunnels and distributed on the outside of the main tunnel arch are arranged opposite to or staggered, eventually forming a complete advance support structure at the top of the main tunnel.

10. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 1, characterized in that, The top-shield integrated machine is used for the construction of the small pilot tunnel. First, the small pilot tunnel is constructed in the jacking mode, and after the construction is set, it is switched to the shield mode to construct the small pilot tunnel. The set distance is 300m to 500m.

11. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 10, characterized in that, During the construction of the pilot tunnel using the jacking method, the pre-support, excavation, initial support, and secondary lining processes are sequentially and cyclically performed within the main tunnel. During the construction of the pilot tunnel using the shield tunneling method, the excavation, initial support, and secondary lining processes are sequentially and cyclically performed within the main tunnel.

12. The method for parallel construction of multiple tunnel processes based on advanced pilot tunnels according to claim 1, characterized in that, The pilot tunnel always maintains a distance that is ahead of the main tunnel face. The set distance is not less than 50m.

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