A variable cross-section tunnel construction method

Abstract

The present invention discloses a variable-section tunnel construction method, including: constructing a first section of the tunnel by a first tunnel boring machine; setting a first receiving well for receiving the first tunnel boring machine at the end position of the first section of the tunnel; in the first receiving well, replacing the first tunnel boring machine with a second tunnel boring machine, the construction section sizes of the first tunnel boring machine and the second tunnel boring machine are different; converting the first receiving well into a starting well of the second tunnel boring machine; constructing a second section of the tunnel by the second tunnel boring machine; setting a second receiving well for receiving the second tunnel boring machine at the end position of the second section of the tunnel. The functions of receiving and starting can be realized through the same working well, thereby achieving the purpose of reducing construction costs and improving construction efficiency. In addition, the construction of different tunnel sections can be realized, which can effectively reduce construction costs compared to traditional integrated switching construction equipment, and the construction method is simple and easy to operate.

Description

Technical Field

[0001] The invention relates to the technical field of underground construction, and in particular to a variable-section tunnel construction method. Background Art

[0002] During the construction of subway section tunnels and platform structures, the section tunnels are usually constructed using the shield method, and the platforms are usually constructed using the open-cut method. However, the open-cut method has a greater impact on the surrounding environment. This problem can be avoided if the platform is constructed using the trenchless pipe jacking method.

[0003] In the prior art, there are shield-pipe jacking integrated equipment, but the tunnels they construct have the same cross-sectional dimensions. However, the dimensions of subway section tunnels and platform end faces are quite different, so it is difficult to apply them to variable diameter working conditions. In addition, the existing shield-pipe jacking integrated equipment is essentially to assemble two systems at the same time to achieve the switching of two functions, but the equipment is expensive. During the jacking process, the shield equipment in front needs to be jacked together, which increases the jacking force and is inconvenient to operate. Summary of the invention

[0004] The purpose of the present invention is to provide a variable cross-section tunnel construction method, which can realize the construction of multiple tunnel sections with different cross-sections.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A variable cross-section tunnel construction method, comprising:

[0007] Construction of the first tunnel section by the first tunnel boring machine;

[0008] A first receiving shaft for receiving the first tunnel boring machine is provided at the end position of the first tunnel section;

[0009] In the first receiving shaft, the first tunnel boring machine is replaced with a second tunnel boring machine, and the construction section sizes of the first tunnel boring machine and the second tunnel boring machine are different;

[0010] Converting the first receiving shaft into a launching shaft of the second tunnel boring machine;

[0011] constructing a second tunnel section by using the second tunnel boring machine;

[0012] A second receiving shaft for receiving the second tunnel boring machine is arranged at the end position of the second tunnel section.

[0013] Preferably, the first tunnel boring machine and the second tunnel boring machine may be tunnel boring machines of different types, or tunnel boring machines of the same type with cutter discs of different diameters.

[0014] Preferably, the first tunnel boring machine is replaced with a second tunnel boring machine, specifically comprising: replacing the cutter disc of the first tunnel boring machine with a cutter disc having a different diameter from the first tunnel boring machine to replace it with the second tunnel boring machine, or replacing the first tunnel boring machine with a second tunnel boring machine that can construct a cross-sectional shape different from the first tunnel boring machine.

[0015] Preferably, the first tunnel boring machine is a shield machine, and the second tunnel boring machine is a pipe jacking machine; replacing the first tunnel boring machine with the second tunnel boring machine specifically includes: removing the outer shells of the front shield, middle shield, and tail shield of the shield machine, the segment assembler, and the shield jack, retaining the shield machine cutter head, main drive structure, and screw conveyor, installing a front end shell at the front end of the shield machine and a rear end shell at the rear end, and expanding the shield machine cutter head into a large-diameter pipe jacking machine cutter head.

[0016] Preferably, the first receiving well is converted into the starting well of the second tunnel boring machine, specifically including: setting a jacking reaction frame, a jacking steel plate, and a jacking jack equipment in the first receiving well, and adjusting the receiving base and guide rail structure in the first receiving well for the starting of the jacking machine.

[0017] Preferably, the first tunnel boring machine is a pipe jacking machine, and the second tunnel boring machine is a shield machine; replacing the first tunnel boring machine with the second tunnel boring machine specifically includes: removing the outer shell of the pipe jacking machine, adjusting the pipe jacking cutter head to a small-diameter shield cutter head, and installing the outer shells of the front shield, middle shield, and tail shield of the shield machine, the segment assembler, and the shield jack.

[0018] Preferably, the first receiving shaft is converted into the starting shaft of the second tunnel boring machine, specifically including: installing a shield reaction frame and a shield steel plate at the top pipe exit position, and adjusting the top pipe receiving base and guide rail structure in the first receiving shaft for the starting of the shield machine.

[0019] Preferably, two tunnel lines are constructed, both including platforms, and the two platforms are expanded by dark excavation to form a large-section platform.

[0020] Preferably, the step of expanding the two platforms by using the dark excavation method specifically includes:

[0021] Drill and grout reinforce the parts of the platform that need to be expanded;

[0022] Mechanically break down the platform to expand the pipe segments required.

[0023] Preferably, after breaking the pipe segments, initial support is constructed using grid arches, shotcrete, connecting bars and steel mesh, and waterproofing and secondary lining construction is carried out after excavation.

[0024] Compared with the prior art, the above technical solution has the following advantages:

[0025] The variable-section tunnel construction method provided by the present invention includes: constructing the first section of the tunnel by a first tunnel boring machine; setting a first receiving well for receiving the first tunnel boring machine at the end position of the first section of the tunnel; in the first receiving well, replacing the first tunnel boring machine with a second tunnel boring machine, the construction section sizes of the first tunnel boring machine and the second tunnel boring machine are different; converting the first receiving well into a starting well of the second tunnel boring machine; constructing the second section of the tunnel by the second tunnel boring machine; setting a second receiving well for receiving the second tunnel boring machine at the end position of the second section of the tunnel. The functions of receiving and starting can be realized through the same working well, thereby achieving the purpose of reducing construction costs and improving construction efficiency. In addition, the construction of different tunnel sections can be realized, which can effectively reduce construction costs compared to traditional integrated switching construction equipment, and the construction method is simple and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic flow chart of a variable cross-section tunnel construction method provided in a specific embodiment of the present invention;

[0028] Figure 2 This is a partial construction diagram of two subway section tunnels and station platform tunnels;

[0029] Figure 3 This is a schematic diagram of the structure of the shield machine;

[0030] Figure 4 It is a structural schematic diagram of the pipe jacking machine;

[0031] Figure 5 The layout diagram of the converted pipe jacking machine and the pipe jacking launch well;

[0032] Figure 6 The layout diagram of the converted shield machine and shield launching shaft;

[0033] Figure 7 This is a cross-section diagram of the platform tunnel expansion construction for a double-track station.

[0034] The reference numerals are as follows:

[0035] 1 is the cutterhead of the shield machine, 2 is the front shield, 3 is the middle shield, 4 is the shield tail, 5 is the screw conveyor, 6 is the shield jack, 7 is the segment assembler, 8 is the main driving structure, 9 is the front end shell, 10 is the rear end shell, 11 is the jacking pipe section, 12 is the jacking jack, 13 is the jacking iron, 14 is the cutterhead of the jacking machine, 15 is the thrust frame, 16 is the jacking steel plate, 17 is the receiving base and guide rail structure of the shield machine, 18 is the shield receiving shaft, 19 is the jacking reaction frame, 20 is the receiving base and guide rail structure of the jacking machine, 21 is the negative ring segment, 22 is the shield reaction frame, and 23 is the shield steel plate. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0037] In the following description, specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0038] A specific embodiment of the present invention provides a variable cross-section tunnel construction method, such as Figure 1 As shown, the following steps are included:

[0039] S100: constructing the first section of the tunnel by using the first tunnel boring machine.

[0040] S200: Setting a first receiving shaft for receiving a first tunnel boring machine at the end position of the first tunnel section.

[0041] S300: In the first receiving shaft, the first tunnel boring machine is replaced with the second tunnel boring machine. The first tunnel boring machine and the second tunnel boring machine can be different types of tunnel boring machines, or the same type of tunnel boring machines with different diameter cutter heads. For example, the first tunnel boring machine can be a shield machine, and the second tunnel boring machine can be a pipe jacking machine, and the cutter heads of the two machines have different diameters. In addition, the first tunnel boring machine can be a pipe jacking machine, and the second tunnel boring machine can be a shield machine; in addition, the first tunnel boring machine and the second tunnel boring machine can both be pipe jacking machines or shield machines. Construction methods such as small-diameter shield to large-diameter pipe jacking, large-diameter pipe jacking to small-diameter shield, large-diameter shield to small-diameter pipe jacking, and small-diameter pipe jacking to large-diameter shield can be realized, and even the conversion of shield-pipe jacking with the same cross-sectional size can be realized. In addition, the first tunnel boring machine can be replaced with a second tunnel boring machine that can construct a cross-sectional shape different from it, such as the conversion of circular shield-rectangular pipe jacking equipment of different sizes or the same size.

[0042] S400: Convert the first receiving shaft into the launching shaft of the second tunnel boring machine. That is, the receiving and launching functions can be realized through the same working shaft, thereby achieving the purpose of reducing construction costs and improving construction efficiency.

[0043] S500: Construction of the second tunnel section by the second tunnel boring machine.

[0044] S600: A second receiving shaft for receiving a second tunnel boring machine is set at the end position of the second tunnel section. When the number of construction sections exceeds two, the above steps can be repeated to achieve the purpose of continuous construction.

[0045] A tunnel construction method provided by an embodiment of the present invention can be applied to the integrated trenchless construction of subway tunnel construction and station platforms, including the construction of a subway section shield tunnel to a station platform top pipe tunnel, and the construction of a subway station platform top pipe tunnel to a section shield tunnel, such as Figure 2 As shown in the figure, the cross-sectional dimensions of the station platform top-tube tunnel I are larger than those of the section shield tunnel II.

[0046] 1. Construction of the subway section shield tunnel to the station platform top pipe tunnel, including:

[0047] A shield receiving shaft 18 is set at the end of shield section a, and the structural bottom plate of the receiving shaft is backfilled with C35 concrete to complete the soil reinforcement of the receiving tunnel;

[0048] Conduct shield posture recheck measurement. According to the elevation of the receiving tunnel door and the center elevation of the shield machine, arrange the shield machine receiving base and guide rail structure 17 in the shield receiving shaft 18 to receive the shield machine. After the installation is completed, re-measure the elevation.

[0049] Chisel out the receiving tunnel door of the shield tunnel and install the waterproof device for the receiving tunnel door;

[0050] The section tunnel is constructed by means of a shield machine;

[0051] After the construction of shield section a is completed, the shield machine is received through the shield receiving shaft and replaced with a pipe jacking machine. Figure 3 and Figure 4 As shown, it specifically includes: removing the outer shells of the front shield 2, the middle shield 3, the tail shield 4, the segment assembly machine 7, the shield jack 12 and other parts not needed by the pipe jacking machine, and retaining the shield machine cutter head 1, the main drive structure 8 and the screw conveyor 5 and other parts required by the pipe jacking machine;

[0052] Adjust the shield receiving base and the guide rail structure 17 so that it can be used for the start of the pipe jacking machine, install the front housing 9 at the front end of the shield machine, install the rear housing 10 at the rear end, and expand the shield machine cutterhead 1 to a large-diameter pipe jacking machine cutterhead 14;

[0053] Convert the shield receiving well 18 into the jacking starting well, such as Figure 5 As shown, specifically including:

[0054] A jacking pipe reaction frame 19 is set at the shield machine exit A, and a jacking pipe steel plate 16 is added behind the jacking pipe reaction frame 19. It should be ensured that the jacking pipe steel plate 16 and the wall surface of the jacking pipe starting shaft are in contact with each other, otherwise high-strength concrete should be poured in the gap to ensure that the back wall is evenly stressed during the jacking construction. The jacking pipe reaction frame 19 should not only have sufficient compressive strength, but also be able to adjust its size according to actual needs to adapt to shield receiving shafts of different sizes;

[0055] Install the pipe jacking jack 12 to provide forward power for the pipe jacking construction. The hydraulic pump station for the pipe jacking machine adopts the hydraulic pump station of the original shield machine. After the installation is completed, the whole machine is debugged and can enter the next process only after it is qualified;

[0056] Install the tunnel door sealing curtain rubber sheet, clean the tunnel entrance embedded bolt holes, etc., install the starting tunnel curtain rubber sheet and circular plate, etc.;

[0057] After the dewatering construction outside the pit, arrange horizontal exploration holes within the scope of the tunnel entrance to check the quality of the reinforcement body and the flow of water and sand. Only when the exploration holes are in good condition and no water or mud and sand flow out, can the jacking start tunnel door be broken. The order of chiseling the tunnel door is from top to bottom;

[0058] Inject thixotropic mud and inject it into the outer wall of the pipe segment through the grouting holes reserved in the pipe segment, so that a complete mud sleeve is formed on the outer wall of the top pipe segment 11;

[0059] Install the thrust frame 15, hoist the jacking pipe section 11, and install the jacking iron 13. After debugging the jacking machine, start the jacking construction of the jacking section b.

[0060] 2. Construction of the subway station platform top pipe tunnel to the section shield tunnel, including:

[0061] A jacking pipe receiving well is set at the end position of the jacking pipe section b;

[0062] In the jacking receiving well, a jacking machine receiving base and a guide rail structure 20 are arranged for the jacking machine to exit the hole;

[0063] The platform is constructed by pipe jacking machine;

[0064] After the construction of pipe jacking section b is completed and the pipe jacking machine reaches the pipe jacking receiving well, the pipe jacking machine is replaced with a shield machine. Figure 3 and Figure 4 As shown, it specifically includes: removing the outer shell of the pipe jacking machine, adjusting the pipe jacking cutter head 14 to a shield cutter head 1 with a small diameter, and installing the outer shells of the front shield 2, the middle shield 3, and the tail shield 4 of the shield machine, the pipe segment assembly machine 7, the shield jack 6, etc.;

[0065] Convert the jacking pipe receiving well into a shield starting well, and adjust the jacking machine receiving base and the guide rail structure 20 for starting the shield machine;

[0066] Strengthening of the ground at the starting tunnel entrance of the shield machine;

[0067] Excavation of the shield tunneling starting hole and installation of the hole sealing device;

[0068] The starting guide rail is installed in the starting tunnel of the shield, and the shield reaction frame 22 and the shield steel plate 23 are installed at the position B of the top pipe exit. Figure 6 As shown;

[0069] Install the negative ring segment 21 and prepare to start shield excavation construction.

[0070] Pipe jacking construction and shield construction are both commonly used trenchless construction technologies in infrastructure construction, and have been widely used in the laying of various types of tunnels and underground pipelines. Since the shield machine has a jacking device in the front, it is more flexible and can be constructed over a long distance with a certain curve radius, while the pipe jacking machine is just the opposite. The jacking force of pipe jacking construction increases with the increase of construction distance, while the jacking force of shield construction theoretically does not change with distance. Therefore, during the construction of subway projects, the shield method is used to construct the interval tunnel. The present invention can realize the expansion construction from a small-sized interval tunnel to a large-section platform by utilizing the advantages of the two trenchless technologies of shield construction and pipe jacking construction. After the previous construction is completed, the existing receiving well structure can be used to complete the adjustment and conversion of the equipment, and the existing receiving well can be used as the starting well of the next project. Compared with the existing shield-pipe jacking integrated machine equipment, the overall cost is lower, and there is no need to consider the conversion of construction methods, pipe sections and other complex processes during underground construction, as well as the connection processing of shield segments and pipe jacking sections, which is conducive to the guarantee of project quality.

[0071] In one embodiment of the present invention, the above construction method can be used to construct two tunnel lines both including platforms, such as Figure 7 As shown, the two lines are preferably parallel to each other and can be constructed successively or simultaneously. After the construction is completed, the two platforms are expanded by dark excavation to form a large-section platform. The construction process includes the following steps:

[0072] Drill holes and grouting are carried out to reinforce the part III of the platform that needs to be expanded. According to the specific spacing between the two lines and the quality of the surrounding soil, support measures such as advanced small-duct grouting and pipe curtain method are selected to ensure construction safety.

[0073] Mechanical demolition of the platform requires the expansion of part of the top pipe segment. In order to avoid affecting the stability of the segment structure during the mechanical demolition process, the demolition sequence is carried out from top to bottom, removing the concrete and cutting off the steel bars in sections.

[0074] After breaking the pipe segments, the initial support is constructed using grid arches, shotcrete, connecting bars and steel mesh. After excavation, the waterproof layer and secondary lining are constructed.

[0075] This embodiment uses a construction process of supporting and excavating the soil between the two platform tunnels to form a large-section station platform, which can reduce environmental and traffic impacts, shorten construction period, and reduce construction risks.

[0076] The tunnel construction method provided by the present invention can be applied to the above-mentioned integrated trenchless construction of subway tunnel construction and station platforms, as well as intercity railway tunnels and their station structures, underground water conveyance tunnels with variable diameters, Y-shaped tunnels and other underground tunnel projects. The following is an example of shield-shield tunnel variable diameter construction:

[0077] Set up a receiving well at the location where the diameter change is required;

[0078] After the previous shield construction is completed, the shield machine is received in the receiving shaft, and the receiving base and guide rail structure of the shield machine are adjusted for the start of the shield machine of the next tunnel;

[0079] Complete the adjustment of cutterheads of different sizes in the receiving shaft, as well as the expansion or reduction of the front shield, middle shield and tail shield of the shield machine;

[0080] Install the reaction frame structure suitable for the next section of shield machine construction, debug the equipment, and prepare for the next section of shield tunnel construction of different sizes.

[0081] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A variable cross-section tunnel construction method, characterized in that: include: Construction of the first tunnel section by the first tunnel boring machine; A first receiving shaft for receiving the first tunnel boring machine is provided at the end position of the first tunnel section; In the first receiving shaft, the first tunnel boring machine is replaced with a second tunnel boring machine, and the construction section sizes of the first tunnel boring machine and the second tunnel boring machine are different; Converting the first receiving shaft into a launching shaft of the second tunnel boring machine; constructing a second tunnel section by using the second tunnel boring machine; A second receiving shaft for receiving the second tunnel boring machine is provided at the end position of the second tunnel section; The first tunnel boring machine and the second tunnel boring machine are tunnel boring machines of different types, or tunnel boring machines of the same type with cutter heads of different diameters; Replacing the first tunnel boring machine with a second tunnel boring machine specifically includes: replacing the cutterhead of the first tunnel boring machine with a cutterhead having a different diameter from the first tunnel boring machine to replace it with the second tunnel boring machine, or replacing the first tunnel boring machine with a second tunnel boring machine that can construct a cross-sectional shape different from the first tunnel boring machine; The first tunnel boring machine is a shield machine, and the second tunnel boring machine is a pipe jacking machine; replacing the first tunnel boring machine with the second tunnel boring machine specifically includes: removing the outer shells of the front shield, middle shield, and tail shield of the shield machine, the segment assembler, and the shield jack, retaining the shield machine cutter head, the main drive structure, and the screw conveyor, installing a front end shell at the front end of the shield machine, installing a rear end shell at the rear end, and expanding the shield machine cutter head into a large-diameter pipe jacking machine cutter head; Converting the first receiving well into a launching well of the second tunnel boring machine specifically includes: setting a jacking reaction frame, a jacking steel plate, and a jacking jack device in the first receiving well, and adjusting a receiving base and a guide rail structure in the first receiving well for launching the jacking machine; Alternatively, the first tunnel boring machine is a pipe jacking machine, and the second tunnel boring machine is a shield machine; replacing the first tunnel boring machine with the second tunnel boring machine specifically comprises: removing the outer shell of the pipe jacking machine, adjusting the pipe jacking cutter head to a shield cutter head with a small diameter, and installing the outer shells of the front shield, middle shield, and tail shield of the shield machine, a segment assembler, and a shield jack; Converting the first receiving shaft into the starting shaft of the second tunnel boring machine specifically includes: installing a shield reaction frame and a shield steel plate at the top pipe exit position, and adjusting the top pipe receiving base and guide rail structure in the first receiving shaft for the starting of the shield machine.

2. The variable cross-section tunnel construction method according to claim 1, characterized in that: Two tunnel lines, both including platforms, were constructed, and the two platforms were expanded using the dark excavation method to form a large-section platform.

3. The variable cross-section tunnel construction method according to claim 2, characterized in that: The dark excavation method is used to expand the two platforms, specifically including: Drill and grout reinforce the parts of the platform that need to be expanded; Mechanically break down the platform to expand the pipe segments required.

4. The variable cross-section tunnel construction method according to claim 3, characterized in that: After breaking the pipe segments, the initial support is constructed using grid arches, shotcrete, connecting bars and steel mesh. After excavation, the waterproof layer and secondary lining are constructed.

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