A mechanized construction method based on tunnel excavation to expand underground space

Abstract

The purpose of the present invention is to provide a mechanized construction method for expanding underground space based on a pilot tunnel to solve the technical problem of low efficiency when digging and expanding upward or inward in a tunnel. The construction method includes the following steps: 1) excavating a pilot tunnel at the designed position of the tunnel; 2) after the pilot tunnel is excavated to a predetermined position, a horizontal channel is excavated at its end, and the horizontal channel extends in the left and right directions; 3) an oblique support pipe is closely set at the front side of the horizontal channel and an inclined support pipe is excavated below the oblique support pipe, and a transition space is gradually enlarged from back to front; 4) a starting space support pipe is closely set at the top of the front side of the transition space, and an excavation starting space is excavated below the starting space support pipe, and the excavation starting space and the transition space form a tunnel boring machine assembly space for assembling a tunnel boring machine; 5) a reaction frame and a tunnel boring machine are installed in the tunnel boring machine assembly space, and the rock and soil body in front of the tunnel boring machine assembly space is excavated to finally form the target underground space.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel excavation, and in particular to a mechanized construction method based on expanding underground space through a pilot tunnel. Background Art

[0002] Civil air defense projects are an important underground infrastructure of the country, coexisting with the existing tunnel operation network but not interconnected. Most underground strategic material storage facilities are single channels with multiple large underground caverns attached to fully utilize their storage and transportation functions, which are difficult to build with conventional excavation technology. The industry has long been trapped in the technical bottleneck of being unable to achieve the "small space to large space" underground, that is, the difficulty of digging out a large underground space horizontally upward in the tunnel channel is high and the effect is poor.

[0003] At present, the main construction methods used in similar underground projects in my country can be summarized as open excavation, mining method, covered excavation, shallow buried tunneling method and shield machine method.

[0004] The Chinese invention patent application with application publication number CN113389579A discloses a method for excavating a vertical tank with a large underground space, including the following steps: 1. Excavating an inclined guide hole; 2. Expanding the top platform; 3. Excavating a guide groove; 4. Excavating the front and rear parts of the guide groove and the remaining surrounding rock of the tank in sequence; using the free surface formed by the guide groove and the flat ground after excavating the tank dome, first excavate the front and rear sides of the guide groove layer by layer from the middle to the periphery of the tank until an inclined surface intersecting with the bottom edge of the guide groove is formed, and the angle of the inclined surface relative to the guide groove is greater than 45°, and then the remaining surrounding rock of the tank is excavated layer by layer from top to bottom; the height of each layer of expansion is controlled at 2-3 meters, and the slag produced by the expansion slides into the guide groove, and finally the contour of the entire tank is excavated. However, this excavation method mainly relies on manual operations such as drilling and blasting in the excavation scene, and the excavation efficiency is low. Summary of the invention

[0005] The purpose of the present invention is to provide a mechanized construction method based on pilot tunnel excavation to expand underground space, so as to solve the technical problems that it is difficult to expand the space from a small space to a large space based on existing or planned tunnels, the construction efficiency is low, and the construction safety cannot be guaranteed.

[0006] To achieve the above-mentioned purpose, the present invention provides a technical solution based on a mechanized construction method for expanding underground space by a pilot tunnel:

[0007] A mechanized construction method based on tunnel excavation to expand underground space, comprising the following steps:

[0008] 1) Excavate a pilot tunnel at the designed tunnel location;

[0009] 2) After the pilot tunnel is excavated to the predetermined position, a horizontal channel is excavated at its end, and the horizontal channel extends in the left and right directions;

[0010] 3) An oblique support pipe is installed at the top of the front side of the transverse passage, and a transition space is excavated under the oblique support pipe. The transition space gradually increases from the back to the front;

[0011] 4) A starting space support pipe is installed closely at the front top of the transition space, and a tunneling starting space is excavated under the starting space support pipe. The tunneling starting space and the transition space form a tunneling machine assembly space for assembling a tunneling machine;

[0012] 5) Install the reaction frame and the TBM in the TBM assembly space, excavate the rock and soil in front of the TBM assembly space, support the tunnel with a temporary structure while the TBM is excavating, then construct the permanent structure and dismantle the temporary structure, finally forming the target underground space.

[0013] Beneficial effects: By excavating a transverse passage at the end of the guide tunnel and then excavating a transition space forward through the transverse passage, the disassembled TBM components can be transported from the guide tunnel through the transverse passage to the TBM assembly space formed by the transition space, and the TBM is assembled in the TBM assembly space. After the assembly is completed, the TBM can excavate the required underground space forward in the TBM assembly space. The setting of the oblique support pipe and the starting space support pipe makes the support and expansion process of the transition space reliable and will not collapse. The support measures are timely during the construction period, and the process of closely laying the oblique support pipe and the starting space support pipe is efficient and convenient. The cross-section of the tubular structure is circular and the overall force strength is high. The setting of the TBM assembly space enables the use of TBMs at the construction location, greatly improving the efficiency of the expansion operation. It can not only ensure that the underground space is set up independently, quickly, efficiently and safely, but also solve the technical bottleneck problem of "small space becomes large space".

[0014] Preferably, the tunnel structure at the pilot tunnel to be excavated uses composite lining segments, and the tunnel opening to be broken uses machinable fiber concrete. The composite lining segments have a better support effect, and the opening part made of fiber concrete is easy to break, which can make the excavation of the pilot tunnel portal easier, and opening the opening saves time and effort.

[0015] Preferably, in step 4), a permanent side wall is first constructed on the top of the front side wall of the transition space, and then the starting space support pipe is installed closely along the reserved area on the top of the permanent side wall. The setting of the permanent side wall can not only support and tighten the transition space, prevent collapse and leakage, but also facilitate the installation of the starting space support pipe, so that it can be positioned and prevent deviation.

[0016] Preferably, before the tunnel boring machine is assembled to excavate the rock and soil mass in front of the tunnel boring machine assembly space, a pile foundation is driven in the tunnel boring machine assembly space, and the pile foundation is used to fix the reaction frame that provides the force for the tunnel boring machine. Before the tunnel boring machine starts, the reaction frame is connected to the pile foundation, and the reaction force provided by the tunnel boring machine is transferred to the pile foundation through the reaction frame, gradually dissipating the reaction force provided by the tunnel boring machine.

[0017] Preferably, the reaction frame has at least two tunnel boring machine reaction units, each of which is arranged on the left and right and fixed to the pile foundation, and each tunnel boring machine reaction unit can provide reaction force to the tunnel boring machine independently. The reaction frame can be fixed to a large number of pile foundations, distributing the force to more pile foundations, and having better stability.

[0018] Preferably, when the rock and soil mass in front of the assembly space of the tunnel boring machine is excavated, after the tunnel boring machine has excavated the target distance, the tunnel boring machine is disassembled and transported back to the assembly space of the tunnel boring machine, and then reassembled to continue excavating the remaining rock and soil mass. After the tunnel boring machine reaches the predetermined position, it is dismantled in the hole to reduce the requirements for construction conditions.

[0019] Preferably, in step 5), when the rock and soil mass in front of the assembly space of the tunnel boring machine is excavated, the rock and soil mass in front of the assembly space of the tunnel boring machine is excavated in at least two layers, and the rock and soil mass in the lower layer is excavated first, and then the rock and soil mass in the upper layer is excavated. The step-by-step excavation of at least two layers can gradually enlarge the excavation starting space, so that the excavated underground space meets the demand, and the excavation process from bottom to top is progressive layer by layer, with clear layers, which is convenient for stable construction.

[0020] Preferably, in step 5), when excavating a single layer of rock and soil, a single rectangular tunnel is excavated in sequence from the middle to both sides. Excavating from the middle to both sides breaks the cross section into small pieces, reduces the exposed area of ​​the face, stabilizes the bottom surface load, makes excavation faster, and the erection of support and the excavated tunnel are in a continuous state, preventing the support or tunnel from being discontinuous, and the left and right heights from being uneven.

[0021] Preferably, in step 4), permanent transition space columns are arranged in the transition space, and temporary steel columns for the starting space are arranged in the excavation starting space in front of the transition space; in step 5), when the tunnel boring machine needs to start at the location of the temporary steel columns for the starting space, the temporary steel columns for the starting space are removed to free up the space required by the tunnel boring machine; after the excavation is completed, the temporary steel columns for the starting space are replaced with permanent columns for the starting space; after the target underground space is completed, the permanent columns for the transition space are arranged in at least two rows in the left and right directions, and the permanent columns for the excavation starting space and the permanent columns for the transition space are arranged in a queue front and back. The setting of temporary steel columns in the starting space ensures a firm support for the excavation starting space, making it easier for the tunnel boring machine to excavate forward from the excavation starting space. When the tunnel boring machine needs to be placed at the location of the temporary steel columns in the starting space, the temporary columns in the starting space will be removed so that the tunnel boring machine can be placed at their location to continue the excavation work. The permanent columns in the excavation starting space and the permanent columns in the transition space are arranged in a queue front and back, which not only forms a smooth passage between the columns, but also ensures that the supporting positions of each column are subjected to the same force, which facilitates the erection and support of the columns at their setting positions.

[0022] Preferably, the starting space support pipe extends horizontally. The horizontally-laid starting space support pipe can guide the excavation of the tunnel boring machine, so that the unit space excavated by the tunnel boring machine extends horizontally to prevent skew. And the horizontally-extended starting space support pipe is convenient for pouring a reinforcement structure at its upper end, which is convenient for construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic cross-sectional view of a tunnel in Example 1 provided by the present invention;

[0024] Figure 2 This is a schematic diagram of the structure after the tunnel, pilot tunnel, cross passage and oblique support pipe are constructed in Example 1 provided by the present invention;

[0025] Figure 3 This is a schematic diagram of the structure after the transition space construction is completed in Example 1 provided by the present invention;

[0026] Figure 4 A schematic diagram of the structure of the pile foundation and the starting space support pipe arranged in the transition space in the embodiment 1 provided by the present invention;

[0027] Figure 5 for Figure 4 Schematic diagram of the structure after the temporary steel columns and hidden columns under the middle starting space support pipe are completed;

[0028] Figure 6 It is a schematic diagram of the state of the rock and soil unit at the bottom of the rectangular tunnel boring machine in Example 1 provided by the present invention when tunneling starts;

[0029] Figure 7 A cross-sectional view of the excavation sequence of the excavation starting space in Example 1 provided by the present invention;

[0030] Figure 8 A top view of the rectangular tunnel boring machine in Example 1 provided by the present invention operating in the tunneling starting space;

[0031] Fig. 9 It is a schematic diagram of the upper structure of the excavation starting space and the rectangular tunnel boring machine starting construction in Example 1 provided by the present invention;

[0032] Fig.10 This is a front view of the two-layer structure of the excavation starting space after it is completed in Example 1 provided by the present invention;

[0033] Fig.11 This is an axonometric diagram of the two-layer structure of the excavation starting space after completion in Example 1 provided by the present invention;

[0034] Fig.12 A schematic diagram of the construction state of setting a secondary lining structure in the excavation starting space in Example 1 provided by the present invention;

[0035] Fig.13 This is a cross-sectional view of the second lining structure after the construction is completed in the excavation starting space in Example 1 provided by the present invention;

[0036] Fig.14 A cross-sectional view of a portal in the to-be-broken area of ​​the upper pilot tunnel of the tunnel in Example 1 provided by the present invention;

[0037] Fig.15 A top view of the underground space after construction is completed in Example 1 provided by the present invention;

[0038] Fig.16 This is a schematic diagram of the structure after the underground space construction is completed in Example 1 provided by the present invention.

[0039] Description of reference numerals:

[0040] 1. Tunnel; 2. Pilot tunnel; 3. Cross passage; 4. Oblique support pipe; 41. End reinforcement; 5. Horizontal support beam; 6. Longitudinal through beam; 7. Bottom structure; 8. Concealed column; 9. Pile foundation; 10. Permanent column of transition space; 101. Permanent column of underground space; 11. Support pipe of starting space; 12. Temporary steel column of starting space; 13. Portal ring beam; 14. Lining segment; 15. Reaction frame; 16. Rectangular TBM; 17. Ramp; 18. Permanent column of starting space of excavation; 19. Composite lining segment; 20. Area to be removed; 21. Secondary lining structure; 22. Bottom longitudinal beam; 23. Top longitudinal beam. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0043] It should be noted that relational terms such as "first" and "second" that may appear are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, terms such as "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements that are not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, elements defined by the sentence "including a...", etc., do not exclude processes and methods that include the elements.

[0044] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" that may appear should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0045] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the term "provided with" that may appear should be understood in a broad sense. For example, the object "provided with" may be a part of the body, or may be arranged separately from the body and connected to the body, and the connection may be a detachable connection or an inseparable connection. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The present invention is further described in detail below in conjunction with embodiments.

[0047] Specific embodiment 1 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0048] The steps of the mechanized construction method based on the pilot tunnel to expand the underground space are:

[0049] 1) Excavate a pilot tunnel at the designed tunnel location;

[0050] 2) After the pilot tunnel is excavated to the predetermined position, a horizontal channel is excavated at its end, and the horizontal channel extends in the left and right directions;

[0051] 3) An oblique support pipe is installed in close proximity to the front side of the cross channel, and a transition space is excavated under the oblique support pipe, which gradually increases from the back to the front;

[0052] 4) A starting space support pipe is installed closely at the front top of the transition space, and a tunneling starting space is excavated under the starting space support pipe. The tunneling starting space and the transition space form a tunneling machine assembly space for assembling a tunneling machine;

[0053] 5) Install a reaction frame and a tunnel boring machine in the tunnel boring machine assembly space, excavate the rock and soil in front of the tunnel boring machine assembly space, and finally form the target underground space.

[0054] Specifically, in step 1), if Figure 1 As shown, the tunnel 1 is excavated by a shield machine. During the excavation of the tunnel 1, the pilot tunnel position mileage is designed in advance, the composite lining segments 19 are assembled to the designed mileage position during the construction of the tunnel 1, and the area to be broken 20 is marked. Fig.14 As shown, a composite lining segment 19 is laid on the tunnel wall of the tunnel 1 outside the area to be broken 20. The composite lining segment 19 is a prior art, and specifically can be the composite lining segment disclosed in the application publication number CN110905548A. The tunnel portal of the area to be broken 20 is made of fiber concrete mixed with concrete and fiber materials. The fiber can be a machinable material such as glass fiber, carbon fiber, aramid fiber, etc. If necessary, auxiliary methods such as freezing or grouting are used to ensure construction safety. The fiber material used in this embodiment is a glass fiber composite material. Figure 2 As shown, a horizontal excavation operation is performed in the area to be demolished 20 on the tunnel 1 , thereby opening a horizontally extending guide tunnel 2 orthogonal to the traveling direction of the tunnel 1 on the tunnel 1 .

[0055] In step 2), after the excavation length of the guide tunnel 2 reaches a predetermined position, a transverse passage 3 is excavated at the end of the guide tunnel 2. The transverse passage 3 extends in the left-right direction, and the position where the transverse passage 3 intersects with the guide tunnel 2 is in the middle of the transverse passage 3. Permanent columns are arranged in the transverse passage 3, and end reinforcement 41 and longitudinal through beam 6 are arranged on the top of the inner wall. In this embodiment, the guide tunnel 2 and the transverse passage 3 are both excavated and formed by the dark excavation method. During the construction process, temporary support is adopted by hanging mesh spraying. If necessary, support such as anchor rods and freezing can be adopted. Subsequently, permanent structures are constructed to form an underground support structure. In order to ensure the stability of the rock and soil, temporary hanging mesh spraying is adopted in the excavation area to avoid long-term exposure of the rock and soil and difficult excavation.

[0056] In step 3), if Figure 3As shown, an oblique support pipe 4 extending obliquely upward is set at the front side of the inner wall end reinforcement 41 of the transverse passage 3, and multiple oblique support pipes 4 are closely arranged on the left and right. At one end of the transverse passage 3, the oblique support pipe 4 is horizontally expanded upward to dig a transition space gradually increasing from back to front in a trumpet shape under the oblique support pipe 4. The transition space is excavated by a step method. While excavating the transition space, a permanent side wall is constructed on the top of the front side wall of the transition space, and a permanent column 10 for the transition space is supported under the oblique support pipe 4. A bottom structure 7 is cast on the bottom surface of the transition space, and a longitudinal through beam 6 and a transverse support beam 5 and other supporting structures are set on the lower side of the oblique support pipe 4 along the excavation direction to make the transition space firm and reliable. Among them, the permanent columns 10 for the transition space are arranged in multiple rows in the horizontal left and right directions. In other embodiments, the bottom of the transition space can also be tilted downward, and the cast bottom structure has a certain slope.

[0057] In step 4), if Figure 4 As shown, a starting space support pipe 11 is set forward above the front side of the trumpet transition space. The starting space support pipe 11 extends forward and backward in the horizontal direction parallel to the bottom surface of the transition space. There are also multiple starting space support pipes 11 arranged closely on the left and right sides to form a tunneling starting space below the starting space support pipe 11. Digging forward along the tunneling starting space can dig out the required underground large space. In the process of tunneling the rock and soil body below the starting space support pipe 11, the permanent side wall of the tunneling starting space, the permanent column 18 of the tunneling starting space, the bottom structure 7, the transverse support beam 5, the hidden column 8 and the temporary steel column 12 of the starting space are set synchronously to prevent the tunneling starting space from collapsing. In the process of tunneling the tunneling starting space, the temporary steel column 12 of the starting space is a detachable support device. The permanent column 18 of the tunneling starting space is arranged in multiple rows in the horizontal left and right directions. The transition space and the tunneling starting space together constitute a tunneling machine assembly space for tunneling machine assembly, construction tunneling and disassembly. In step 5), if Figure 5 and Figure 6 As shown, the parts of the tunnel boring machine are transported to the tunnel boring machine assembly space through the guide tunnel 2 and the transverse passage 3, the tunnel boring machine is assembled in the tunnel boring machine assembly space, and then the tunnel boring machine digs forward from the tunneling starting space. Figure 6As shown, in order to ensure the thrust force when the tunnel boring machine moves forward, a reaction frame 15 is provided at the rear of the tunnel boring machine. The reaction frame 15 is a two-frame assembled structure, that is, the reaction frame 15 has two tunneling reaction force units. The reaction frame 15 can provide reaction force for the tunnel boring machine when the tunnel boring machine is excavating. Pile foundations 9 are vertically driven downward on the bottom surface of the tunnel boring machine assembly space. The pile foundations 9 are used to connect with the reaction frame 15, so that the tunnel boring machine can be supported by the reaction frame 15 fixedly connected to the pile foundations 9. Specifically, the two-frame assembled reaction frame 15 includes two independent reaction frame units, each of which can be connected to the rear end of the tunnel boring machine, so as to cooperate or independently provide a reverse thrust for the tunnel boring machine. The tunneling reaction force units of the two reaction frames 15 are arranged on the left and right, and are respectively fixedly connected to a plurality of pile foundations 9 in the tunnel boring machine assembly space. Thereby, the reverse thrust force of the tunnel boring machine is distributed to more pile foundations 9, so that the tunnel boring machine has better stability during tunneling.

[0058] In step 5), if Figures 7 to 9 As shown, the tunnel boring machine is a rectangular tunnel boring machine 16. The construction method of the rectangular tunnel boring machine 16 in the tunnel boring machine assembly space adopts a multi-layer rock and soil unit excavation method, and the number of soil unit excavation layers is selected according to the required size of the underground space. The excavation process in this embodiment adopts a double-layer rock and soil unit excavation method, wherein each layer of excavated rock and soil includes four rock and soil units in the horizontal direction. Figure 7 As shown in the figure, the excavation sequence of each rock and soil unit is to first excavate A1-A4 in the lower layer, and then excavate a1-a4 in the upper layer, that is, to excavate a single rectangular tunnel in sequence from bottom to top, from the middle to both sides. Figure 8 As shown, when the rectangular tunnel boring machine 16 needs to start excavation at the location of the temporary steel column 12 in the starting space, the temporary steel column 12 in the starting space needs to be removed to make room for the rectangular tunnel boring machine 16. During the excavation construction process, the detachable temporary steel side walls and prefabricated concrete and lining segments 14 are synchronously assembled in the excavation soil unit. When the excavation of each unit is completed, the permanent columns 101, top longitudinal beams 23 and bottom longitudinal beams 22 of the underground space are continued to be constructed in the excavated unit space. At the same time, the temporary steel side wall structure is removed and the permanent columns 18 of the starting space are constructed at the location where the temporary steel column 12 in the original starting space is set. If it is necessary to continue excavating forward, the target underground space excavated by the tunnel boring machine can be used as the excavation starting space for the next target underground space, and horizontal excavation continues forward.

[0059] In step 5), if Figures 7 to 9As shown, the tunnel boring machine assembly space raises the tunnel boring machine by a distance of one tunnel boring machine height through a steel stand, so that the tunnel boring machine is used to construct the tunnel boring machine assembly space of the rock and soil unit located on the upper layer. The structural depth can be changed according to the design requirements of the required underground space structure, and the construction and excavation of the above-mentioned rectangular tunnel boring machine 16 are repeated to construct and excavate the required multi-layer rock and soil underground space structure. The number of construction layers of the soil unit in this embodiment is two layers, but the number of layers can also be increased according to the needs of the underground space. After the construction of the tunnel soil unit, its structure adopts a support method combining temporary structure and permanent structure. After the single-layer excavation is completed, the temporary structure can be converted into a permanent structure to form a single-layer permanent force-bearing structure. It should be noted that when the rectangular tunnel boring machine 16 in this embodiment excavates a single rock and soil unit, when the rectangular tunnel boring machine 16 excavates to the target distance, the tunnel boring machine needs to be dismantled and transported back to the tunnel boring machine assembly space, and then the tunnel boring machine is reassembled in the trumpet transition space at the rear side of the tunnel boring machine assembly space to continue excavating the remaining units of rock and soil.

[0060] like Fig.10 and Fig.11 The figure shows the construction schematic diagram after the tunnel boring machine in this embodiment has completed the tunnel boring. The positions where the oblique support pipes 4 are inserted in the transverse channel 3, the supporting contact positions of the permanent columns 10 in each transition space and the oblique support pipes 4, and the connection positions of the transverse support beams 5, vertical support beams and the oblique support pipes 4 or the starting space support pipes 11 are all reinforced by pouring concrete. A removable lining segment 14 is provided between the lower channel and the upper channel excavated by the rectangular tunnel boring machine 16. After the temporary structure is removed after the tunnel boring of each partition, the post-cast strip is waterproofed and connected with the permanent structure by cast-in-place to form a permanent structure of the underground space. The secondary lining structure 21 is constructed and waterproofed. The secondary lining structure 21 is a frame-shaped frame. The target underground space is provided with a bottom longitudinal beam 22 and a top longitudinal beam 23 on the secondary lining structure 21. Permanent columns 101 for the underground space are erected between the bottom longitudinal beam 22 and the top longitudinal beam 23 to reinforce and support the target underground space. Fig.12 and Fig.13 As shown, after the target underground space is opened and reinforced, each lining segment 14 can be removed. Fig. 9 As shown, a portal ring beam 13 is also provided between the top of the secondary lining structure 21 and the starting space support pipe 11 in the target underground space, so as to firmly connect the starting space support pipe 11 and the excavation starting space support.

[0061] like Fig.15 and Fig.16 As shown, after the underground space is completed as a whole, the temporary steel side walls in the middle will be completely demolished, and permanent columns, bottom longitudinal beams 22, secondary lining structures 21 and post-cast strips will be constructed to finally form a permanent structure of the underground space.

[0062] In this embodiment, the transition space permanent columns 10 are arranged in two rows in the left-right direction, and the spacing between the two rows of transition space permanent columns 10 is equal to the spacing between the two adjacent left and right excavation starting space permanent columns 18, so that the excavation starting space permanent columns 18 and the transition space permanent columns 10 are arranged in a queue front and back. In other embodiments, the transition space permanent columns can also be arranged in more than three rows in the left-right direction. In this embodiment, a ramp 17 is provided at one end of the bottom structure 7 connected to the transverse channel 3 to facilitate the transportation of the excavator components.

[0063] Specific embodiment 2 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0064] The difference from Example 1 is that in Example 1, the reaction frame 15 is a two-frame assembled structure, including two tunnel boring machine reaction units. In this embodiment, more than two reaction frames are provided, and each reaction frame unit is connected to a plurality of pile foundations so that the number of rock and soil units at different levels can be increased, and the volume of the target underground space can be correspondingly increased.

[0065] Specific embodiment 3 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0066] The difference from Example 1 is that in Example 1, the position where the transverse channel 3 intersects with the guide hole 2 is in the middle of the transverse channel 3. In this embodiment, the transverse channel is connected to the guide hole at one end and connected to the other end laterally, or the guide hole is connected to the side of the transverse channel.

[0067] Specific embodiment 4 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0068] The difference from Example 1 is that in Example 1, a pile foundation 9 is driven in the assembly space of the tunnel boring machine, and the pile foundation 9 is used to fix with a reaction frame 15 that provides a force for the tunnel boring machine. In this embodiment, the reaction frame of the tunnel boring machine is supported and provides a reaction force by a bracket connected to the inner wall of the transition space.

[0069] Specific embodiment 5 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0070] The difference from Example 1 is that in Example 1, the rock and soil mass in front of the assembly space of the tunnel boring machine is divided into two layers, and the rock and soil mass in the lower layer is excavated step by step. When excavating, the rock and soil mass in the lower layer is excavated first, and then the rock and soil mass in the upper layer is excavated. In this embodiment, the rock and soil mass in the upper layer can also be excavated first, and then the rock and soil mass in the lower layer is excavated. In other embodiments, the assembly space of the tunnel boring machine can be excavated into more than two layers, and the volume and area of ​​the excavated underground space are increased.

[0071] Specific embodiment 6 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0072] The difference from Example 1 is that in Example 1, the spacing between two adjacent rows of transition space columns is equal to the spacing between two adjacent rows of excavation starting space columns on the left and right. In this embodiment, the spacing between two adjacent rows of transition space columns may not be equal to the spacing between two adjacent rows of excavation starting space columns, and the spacing between permanent columns is changed and adjusted according to the actual supporting balance effect of the starting space support pipe and the oblique support pipe.

[0073] Specific embodiment 7 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0074] The difference from Example 1 is that in Example 1, in step 5), when excavating a single layer of rock and soil, a single rectangular tunnel is excavated in sequence from the middle to the two sides. In this embodiment, the excavation is carried out in a jump-type distribution in the order of first the middle to the two sides, but the specific process of opening is not in a close process, that is, a single rectangular tunnel may not be close to each other in the horizontal direction during excavation, and the two are excavated with a distance of one tunnel between them, and then the middle interval is excavated. In other embodiments, excavation can also be carried out in a sequential excavation method of excavating from the two sides first and then the middle, or from one side of the excavation position to the other side, and the order of excavation up and down can also be the order of up first and then down.

[0075] Specific embodiment 8 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0076] The difference from Example 1 is that in Example 1, the position where the transverse channel intersects with the guide hole is in the middle of the transverse channel. In this embodiment, the transverse channel is a one-way channel with one end connected to the guide hole and the other end extending laterally.

[0077] Specific embodiment 9 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0078] The difference from Example 1 is that in Example 1, a horizontally extending guide tunnel 2 orthogonal to the traveling direction of the tunnel 1 is opened on the tunnel 1. In this embodiment, the extension direction of the guide tunnel can be arranged to be inclined upward or downward, and adjusted according to the actual tunnel working conditions.

[0079] Specific embodiment 10 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0080] The difference from Example 1 is that in Example 1, the transverse channel is a channel with an arched top in cross section. In this embodiment, the transverse channel is a channel with a circular or rectangular cross section, and a cast reinforcement structure is applied on the top of the channel.

[0081] Specific embodiment 11 of the mechanized construction method based on the pilot tunnel excavation and underground space excavation provided by the present invention:

[0082] The difference from Example 1 is that in Example 1, the starting space support pipe extends horizontally. In this embodiment, the starting space support pipe is set upwardly inclined.

[0083] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions recorded in the aforementioned embodiments without creative work, or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mechanized construction method based on tunnel excavation to expand underground space, characterized in that: The following steps are involved: 1) Excavating a pilot tunnel (2) at the designed location of the tunnel (1); 2) After the guide tunnel (2) is excavated to a predetermined position, a transverse passage (3) is excavated horizontally at the end thereof, and the transverse passage (3) extends in the left-right direction; 3) An oblique support pipe (4) is installed in close contact with the front side of the transverse passage (3) and extends obliquely upward, and a transition space is excavated below the oblique support pipe (4), wherein the transition space gradually increases from the back to the front; 4) A starting space support pipe (11) is installed closely at the top of the front side of the transition space, and a tunneling starting space is excavated below the starting space support pipe (11). The tunneling starting space and the transition space form a tunneling machine assembly space for assembling a tunneling machine; 5) A reaction frame (15) and a tunnel boring machine are installed in the tunnel boring machine assembly space, and the rock and soil in front of the tunnel boring machine assembly space are excavated. When the tunnel boring machine is excavating, the tunnel is supported by a temporary structure, and then a permanent structure is constructed and the temporary structure is dismantled, so as to finally form the target underground space.

2. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 1 is characterized in that: The tunnel (1) structure at the pilot tunnel (2) to be excavated adopts a composite lining segment (19), and the tunnel opening to be broken adopts a cuttable fiber concrete.

3. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 1 or 2, characterized in that: In step 4), a permanent side wall is first constructed on the top of the front side wall of the transition space, and then the starting space support pipe (11) is installed closely along the reserved area on the top of the permanent side wall.

4. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 1 or 2, characterized in that: Before the tunnel boring machine is assembled to excavate the rock and soil mass in front of the tunnel boring machine assembly space, a pile foundation (9) is driven in the tunnel boring machine assembly space. The pile foundation (9) is used to be fixed to a reaction frame (15) that provides an acting force for the tunnel boring machine.

5. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 4 is characterized in that: The reaction frame (15) has at least two tunnel boring machine reaction units, each tunnel boring machine reaction unit is arranged on the left and right and is fixed to the pile foundation (9), and each tunnel boring machine reaction unit can independently provide a reaction force to the tunnel boring machine.

6. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 1 or 2, characterized in that: When excavating the rock and soil in front of the TBM assembly space, after the TBM has excavated the target distance, the TBM is disassembled and transported back to the TBM assembly space, and then reassembled to continue excavating the remaining rock and soil.

7. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 1 or 2, characterized in that: In step 5), when the rock and soil mass in front of the assembly space of the tunnel boring machine is excavated, the rock and soil mass in front of the assembly space of the tunnel boring machine is divided into at least two layers, upper and lower, and excavated in steps. When excavating, the rock and soil mass in the lower layer is excavated first, and then the rock and soil mass in the upper layer is excavated.

8. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 7 is characterized in that: In step 5), when excavating a single layer of rock and soil, a single rectangular tunnel is excavated closely in sequence from the middle to both sides.

9. The mechanized construction method based on expanding underground space by pilot tunneling according to claim 1 or 2, characterized in that: In step 4), a permanent transition space column (10) is set in the transition space, and a temporary starting space steel column (12) is set in the excavation starting space on the front side of the transition space; in step 5), when the tunnel boring machine needs to start at the location of the temporary starting space steel column (12), the temporary starting space steel column (12) is removed to free up the space required by the tunnel boring machine; after the excavation is completed, the temporary starting space steel column (12) is replaced with a permanent starting space column (18); after the target underground space is completed, at least two rows of permanent transition space columns (10) are arranged in a left-right direction, and the permanent excavation starting space columns (18) and the permanent transition space columns (10) are arranged in a queue front and back.

10. The mechanized construction method based on tunnel excavation and underground space expansion according to claim 1 or 2, characterized in that: The starting space support pipe (11) extends horizontally.

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