A method for rapidly constructing a large-section tunnel

Abstract

The application discloses a kind of fast construction methods of large-section tunnel, comprising: (1), using small shield machine or TBM to the large-section tunnel to be constructed is advanced tunnel construction, forms advanced tunnel section, and the section diameter of advanced tunnel is set to 2-6 meters;(2), using expansion shield machine or TBM to the tail of advanced tunnel section is expanded tunnel construction, forms expansion tunnel section, and the section diameter of expansion tunnel section is set to greater than 10 meters;Small shield machine or TBM used in step (1) and expansion shield machine or TBM used in step (2) are integrated connection, so that step (1) and step (2) are continuously carried out, and then the large-section tunnel is integrally formed.The fast construction method of the application can realize the rapid excavation of the whole tunnel, realize the construction speed of 7km / month, increase the speed of conventional shield construction method by 4-10 times, has the advantages of high excavation speed, low power consumption and low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground construction, and particularly relates to a construction method suitable for a tunnel with a section greater than 4 meters or underground engineering. BACKGROUND

[0002] At present, in the process of tunnel excavation and underground engineering with a large section, most of the full-face tunnel boring machines are used for construction, and a large-section tunnel is formed by one-time excavation. However, for a large tunnel boring machine with a section greater than 4 meters, the fastest construction speed is about 1000 meters per month. In terms of construction cost, the higher the tunnel section, the higher the construction cost. The cost of a common soft soil tunnel with a section of about 14 meters is close to 300,000 yuan per meter. Therefore, the full-face tunnel boring machine in the prior art has the defects of high cost, slow excavation speed and high construction cost.

[0003] In addition, the tunnel boring machine has a high risk in the construction process, and the tool changing time and maintenance time are relatively long. In the prior art, the tunnel boring machine with a section greater than 10 meters has more stoppage failures in the construction process, and most of them are difficult to rescue, especially some over-river and over-sea shield tunnels.

[0004] For example, a method for expanding a shield tunnel to build a large-section tunnel by using a mine method is disclosed in Chinese Patent Application No. 202010676330.8, which comprises the following steps: S1, using a shield method to excavate a mountain body and using prefabricated steel pipe segments to assemble a section of shield tunnel; S2, expanding the shield tunnel in the opposite direction towards the entrance at the deep part of the section of shield tunnel by using a mine method, and gradually removing the prefabricated steel pipe segments during the expansion process; S3, after the expansion of the section of shield tunnel is completed, repeating the steps S1 and S2 until the construction of the large-section tunnel is completed. However, the present application still has the following shortcomings or deficiencies: (1) the tunnel is excavated by using a manual loader of the mine method, which has low construction efficiency and prolongs the construction period; (2) the mine method needs to use the way of drilling and blasting to destroy all the supports assembled in the early stage, which causes great waste of parts.

[0005] For example, Chinese Patent Application No. 202011193128.6 discloses a method for excavating a large-section tunnel, which comprises the following steps: excavating a small-section tunnel; initially supporting the small-section tunnel; expanding the small-section tunnel to the height of the large-section tunnel; laterally expanding and initially supporting the large-section tunnel by laterally expanding the sidewall of the small-section tunnel in a direction perpendicular to the center line of the small-section tunnel to the width of the large-section tunnel and initially supporting the large-section tunnel; excavating the large-section tunnel by dividing the large-section tunnel into several guide holes and excavating the guide holes using a conventional large-section excavation method; and applying secondary lining. However, the invention still has the following shortcomings or deficiencies: (1) most of the processes are manually excavated, which is labor-intensive and has high construction cost; (2) the construction process is complex and cannot be streamlined, which slows down the construction progress.

[0006] Therefore, it is an urgent problem in the industry to provide a new method for quickly constructing a large-section tunnel with high automation, fast construction speed, low comprehensive cost, and high cost performance. SUMMARY

[0007] In view of the deficiencies of the prior art, one of the purposes of the present application is to provide a method for quickly constructing a large-section tunnel, which can achieve fast and safe construction of the large-section tunnel, high safety and low construction cost during the tunnel operation period, and ensure the fast, safe and economical construction of the tunnel.

[0008] To achieve the above-mentioned purposes, the present application provides a method for quickly constructing a large-section tunnel, which comprises the following steps: (1) using a small shield machine or TBM to perform advanced tunnel construction on a large-section tunnel to be constructed to form an advanced tunnel section, wherein the cross-sectional diameter of the advanced tunnel is set to 2-6 meters; (2) using an expansion shield machine or TBM to perform expansion tunnel construction on the tail of the advanced tunnel section to form an expansion tunnel section, wherein the cross-sectional diameter of the expansion tunnel section is set to be greater than 10 meters; wherein the small shield machine or TBM used in step (1) and the expansion shield machine or TBM used in step (2) are integrally connected, so that steps (1) and (2) are continuously performed, thereby integrally forming the large-section tunnel.

[0009] Wherein, TBM in step (1) and step (2) is the abbreviation of Tunnel Boring Machine, which means full-face tunnel boring machine, which can perform excavation, support, and slag removal construction processes in parallel and continuous operation.

[0010] The cross-sectional diameter of the advanced tunnel is set to 2-6 meters, which facilitates the entry of construction personnel into the advanced tunnel section for maintenance.

[0011] Optionally, the distance between the front end of the advanced tunnel section and the front end of the advanced expansion tunnel section is set to 10-100 meters.

[0012] Optionally, during the process of step (1), the generated muck is transported to the tail of the advanced tunnel section in real time.

[0013] Optionally, in step (1), the construction of the advanced tunnel comprises constructing temporary support of the advanced tunnel, forming an advanced support section, and the advanced support section is connected with the expanded tunnel section.

[0014] Optionally, in step (1), the temporary support of the advanced tunnel comprises automatically assembling pipe segments or expansion joints.

[0015] Optionally, in the temporary support of the advanced tunnel in step (1), further comprising: at the advanced tunnel section at the rear side of the small shield machine or TBM used in step (1), a plurality of holes are reserved in the radial direction or the lateral axial direction, a hole pipe is arranged in the plurality of holes for sealing, and the outer stratum of the advanced tunnel section is reinforced.

[0016] Optionally, in step (2), the construction of the expanded tunnel comprises removing the advanced support accessories of the advanced support section, and conveying the advanced support accessories to the head of the advanced tunnel section in real time to continue constructing the temporary support of the advanced tunnel, thereby recycling the advanced support accessories.

[0017] Optionally, in step (2), the construction of the expanded tunnel comprises assembling pipe segments without stopping or using extruded concrete method for lining.

[0018] Optionally, one or more small shield machines or TBMs are used in step (1), and one or more expanded shield machines or TBMs are used in step (2), wherein each small shield machine or TBM used in step (1) is sequentially and integrally connected with each expanded shield machine or TBM used in step (2), so as to expand once or multiple times, thereby integrally forming the large-section tunnel.

[0019] Optionally, steps (1) and (2) are carried out by using fully mechanized devices.

[0020] The present application at least has the following advantages: (1) the whole tunnel can be excavated quickly, the construction speed is 7km / month, the speed of the conventional shield construction method in the prior art is increased by 4-10 times; (2) the method is suitable for large-section tunnel construction, the tunnel section can be regular shape such as circular, rectangular or horseshoe shape, or irregular shape, and is suitable for all geological conditions; (3) the advanced tunnel section is temporarily supported, the stratum outside the advanced tunnel section is reinforced and treated, the whole tunnel geology is improved, the tunnel is excavated quickly, the water stopping, settlement prevention, expansion prevention, tunnel floating or sinking prevention and other effects are achieved, the geological conditions for cutter replacement and cutter head maintenance of the expansion shield machine are provided, the special stratum such as boulder, spherical weathering and fault fracture zone is pretreated, the tunnel is constructed quickly and safely, and good conditions for the operation safety and quality of the whole tunnel are provided; (4) the expansion tunnel section is better excavated due to the loosening of the advanced tunnel section and the release of the stratum stress, the tunnel is excavated faster, the power consumption is smaller, and the cost is lower. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A flow chart of the method for quickly constructing a large-section tunnel is shown.

[0022] Figure 2 A schematic diagram of an engineering machine applying the method for quickly constructing a large-section tunnel is shown. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0024] The various terms appearing in the present document are only for the purpose of describing the specific embodiments and are not intended to be limiting on the present application. The singular form is intended to include the plural form unless the context clearly indicates otherwise. When the terms "comprise" and / or "comprising" are used in the present specification, these terms indicate that the features, integers, steps, operations, elements, and / or components mentioned in the specification are present, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0025] The method for quickly constructing a large-section tunnel of the present application will be described in detail below with reference to the drawings. As shown in Figure 1As shown, in a non-limiting embodiment, firstly, in step S1, a small tunnel boring machine (TBM) is used to construct an advanced tunnel section for the large-section tunnel to be built, with the cross-sectional diameter of the advanced tunnel set to 2-6 meters. Subsequently, in step S2, a widening tunnel boring machine (TBM) is used to widen the tail of the advanced tunnel section, forming a widened tunnel section with a cross-sectional diameter greater than 10 meters. In this non-limiting embodiment, the small TBM used in step S1 and the widening tunnel boring machine (TBM) used in step S2 are integrated, thereby allowing steps S1 and S2 to be performed continuously, resulting in the integral formation of the large-section tunnel.

[0026] The small tunnel boring machine (or advanced tunnel boring machine) or TBM used in step S1 can utilize the conventional subway tunnel boring machines or TBMs currently widely available in the Chinese market. Due to the large stock and numerous idle subway tunnel boring machines or TBMs in China, they can be appropriately modified for use, thereby saving significant funds and resources. Step S2 uses a widening tunnel boring machine or TBM, whose overall structural design and parameter performance allow for better rapid tunneling. Because of the advanced tunnel as the free face, the widening tunnel boring machine or TBM can employ rock-breaking mechanisms and parameter performance different from conventional full-face tunnel boring machines or TBMs, such as oblique cutting.

[0027] like Figure 2 As shown, during the construction of the advanced tunnel section in step S1, the excavation cross-section diameter of the cutterhead 2 of the small shield machine 1 is generally between 2 and 6 meters, which facilitates personnel access for maintenance. Moreover, the front end of the advanced tunnel section needs to be excavated 10 to 100 meters ahead of the tunnel section.

[0028] To improve efficacy, such as Figure 2 As shown, a screw conveyor 3 and a continuous belt conveyor 4 connect the small tunnel boring machine 1 and the widening tunnel boring machine 10. During the construction of the advanced tunnel section in step S1, the excavated soil can be transported to the end of the tunnel via the screw conveyor 3 and the continuous belt conveyor 4, and then transferred out of the tunnel via the equipment in the widening tunnel section. Similarly, materials and spare parts required during the construction of the advanced tunnel section can also be transferred to the advanced tunnel section via the widening tunnel section.

[0029] As another non-limiting implementation, in step S1, temporary support for the advanced tunnel is constructed to form an advanced support section, which is connected to the widened tunnel section 11. The temporary support for the advanced tunnel includes: steel pipe segments or expansion joints 5 (such as...). Figure 2(As shown). Specifically, the small tunnel boring machines used in the advanced tunnel section construction employ automatic steel segment assembly, expansion joint technology, or the extruded concrete (ECL) method to form an advanced support section connected to the subsequent widened tunnel section. This eliminates the need to stop construction to build the internal lining, thus enabling continuous and rapid excavation. Under this continuous excavation, the construction speed of the advanced tunnel section can reach 4–10 meters per hour, with the fastest monthly excavation speed exceeding 7 km / h.

[0030] The temporary support for the advanced tunnel in step S1 also includes: reserving several holes radially or axially in the advanced tunnel section located behind the small shield tunneling machine or TBM used in step S1; installing orifice pipes in these holes for sealing; and reinforcing the outer strata of the advanced tunnel section. Thus, in the area behind the tunneling machine where there is operational space, the advanced tunnel section utilizes automated radial drilling or geological improvement measures, such as core drilling or geological improvement, to achieve greater space. This provides more stable geological conditions for the replacement or maintenance of the cutterhead 9 of the tunnel boring machine 10, while ensuring rapid and safe tunnel construction and safe tunnel operation.

[0031] In addition, auxiliary facilities such as piles and walls can be constructed radially in the advanced tunnel section to facilitate the maintenance and modification of subsequent excavation machinery.

[0032] During step S2, the tail of the advanced tunnel section is connected to the head of the widened tunnel section. The widened tunnel section is widened using mechanized excavation or large-scale full-face tunneling equipment. The widened tunneling machine can use the advanced tunnel section for partial support and guidance.

[0033] In this non-limiting embodiment, in step S2, the tunnel widening construction includes removing the pre-support components (lining) of the pre-support section, such as steel segments or expansion joints 5, and passing the pre-support components through... Figure 2 The screw conveyor 3 and continuous belt conveyor 4 shown are used to transport materials to the head of the advanced tunnel section in real time, reuse them, continue to carry out temporary support for the advanced tunnel, and then recycle the advanced support accessories. At the same time, the excavated tunnel section can be sealed through the lining structure of the advanced tunnel section.

[0034] Therefore, the excavation machinery used for widening the excavation section, such as Figure 2 The material transfer crane 7 and the slag transfer device 8 shown are responsible for the transfer of materials and slag in the advanced tunnel section. In addition, due to the large cross-section of the expanded tunnel section, it is possible to assemble the segments without stopping the machine or to use the extrusion concrete method for lining.

[0035] By using the construction method of the present application, the advanced tunnel section and the expanded tunnel section can be constructed synchronously or asynchronously, by using multiple sets of the small tunneling machine or small shield machine used in step S1 as the advanced tunnel construction, and connecting one or more sets of the expanded shield machine used in step S2 as the expanded equipment, to realize the construction of the large-section tunnel through one expansion or multiple expansions.

[0036] While the preferred embodiments of the application have been described above in detail, it is understood that no limitations of the scope of the application are intended to be implied therefrom and that other modifications and variations can be made therein by those skilled in the art without departing from the spirit and scope of the application.

Claims

1. A method for rapid construction of large-section tunnels, characterized in that, Includes the following steps: (1) Using a small tunnel boring machine to construct an advanced tunnel section for a large-section tunnel to be built, the diameter of the advanced tunnel section is set to be 2-6 meters; and (2) Use a tunnel boring machine or TBM to excavate the tail of the advanced tunnel section to form an expanded tunnel section. The cross-sectional diameter of the expanded tunnel section is set to be greater than 10 meters. Among them, the small shield tunneling machine used in step (1) and the widening shield tunneling machine or TBM used in step (2) are integrated and connected so that step (1) and step (2) are carried out continuously, thereby making the large cross-section tunnel integrally formed. In step (1), the advanced tunnel construction includes the construction of temporary support for the advanced tunnel to form an advanced support section, which is connected to the excavated tunnel section. The temporary support of the advanced tunnel section and the reinforcement and treatment of the strata outside the advanced tunnel section are used for water stoppage, settlement prevention, and prevention of the excavated tunnel from floating or sinking. In step (1), the temporary support for the advanced tunnel includes: automatically assembled segments or expansion joints; In the temporary support of the advanced tunnel in step (1), it also includes: reserving a number of holes in the radial or lateral axial direction at the advanced tunnel section located on the rear side of the small shield machine used in step (1), setting orifice pipes in the number of holes for sealing, and reinforcing the outer strata of the advanced tunnel section. The distance between the front end of the advanced tunnel section and the front end of the expanded tunnel section is set to 10-100 meters. In step (1), one or more small shield tunneling machines or TBMs are used, and in step (2), one or more excavation shield tunneling machines or TBMs are used. Each small shield tunneling machine or TBM used in step (1) is sequentially and integrated with each excavation shield tunneling machine or TBM used in step (2) so that the large-section tunnel can be formed as a whole after one or more excavations. The small tunnel boring machine is connected to the tunnel boring machine by a screw conveyor and a continuous belt conveyor. During the construction of the advanced tunnel section in step S1, the excavated soil is transported to the end of the tunnel by the screw conveyor and the continuous belt conveyor. In step (2), the tunnel expansion construction includes dismantling the advanced support components of the advanced support section and transmitting the advanced support components to the head of the advanced tunnel section in real time to continue the temporary support of the advanced tunnel, thereby recycling the advanced support components. The tunnel widening construction includes assembling tunnel segments without stopping the machine or lining the widened tunnel section using the extrusion concrete method.

2. The rapid construction method for a large-section tunnel as described in claim 1, characterized in that, Steps (1) and (2) are performed using fully mechanized equipment.

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