A construction method for a working well

Abstract

The present invention belongs to the field of tunnel engineering, and in particular, relates to a method for constructing a working pit. The method for constructing a working pit provided by an embodiment of the present invention includes the following steps: S1, prefabricating a plurality of sub-caisson blocks; S2, assembling the plurality of sub-caisson blocks into a first caisson block, a second caisson block, and a third caisson block; S3, filling the opening of the side wall of the second caisson block with lattice steel to close the side wall of the second caisson block; S4, excavating a foundation pit and placing the first caisson block, the second caisson block, and the third caisson block into the foundation pit in sequence. Through the above method, an opening is set on the side wall of the second caisson block, and the opening of the side wall of the second caisson block is filled with lattice steel. During shield or pipe jacking construction, the lattice steel is dismantled in blocks, and the dismantled lattice steel can be recycled and reused, thereby avoiding the need to chisel out the enclosure structure of the opening in the closed caisson, reducing the engineering workload of the enclosure structure, and improving work efficiency.

Description

Technical Field

[0001] The invention belongs to the field of tunnel engineering, and in particular relates to a construction method of a working pit. Background Art

[0002] With the rapid development of rail transit construction in major cities in my country, due to the shortage of ground land resources in cities, the development of road networks has gradually shifted from above ground to underground in densely populated and ground-building areas, and underground road networks built in the form of tunnels have been applied. In the construction of underground tunnel projects, shield method and pipe jacking method are the main construction methods. When using shield method or pipe jacking method to construct tunnels, it is first necessary to excavate foundation pits at the beginning and end of the tunnel to build working wells, which are used as assembly and disassembly wells for shields and their equipment. The working well is usually constructed by open excavation method, first constructing the retaining structure and then excavating the foundation pit to construct the working well structure. When shield or pipe jacking is constructed, it is usually necessary to chisel out the retaining structure at the opening to facilitate shield or pipe jacking construction. This practice is often complicated to construct and will cause waste of retaining structure, with poor economic benefits. Summary of the invention

[0003] In view of this, an embodiment of the present invention provides a method for constructing a working pit to solve the technical problem of how to avoid the complexity and waste of the construction of the enclosure structure during shield or pipe jacking construction.

[0004] To solve the above technical problems, the technical solution of the embodiment of the present invention is implemented as follows:

[0005] An embodiment of the present invention provides a method for constructing a working pit, and the method for constructing a working pit comprises the following steps:

[0006] S1. Prefabricate multiple sub-caisson blocks;

[0007] S2, assembling the plurality of sub-caisson blocks into a first caisson block, a second caisson block and a third caisson block; wherein the first caisson block and the third caisson block are hollow bodies with closed side walls; the second caisson block is a hollow body with open side walls; the total length of the first caisson block in the vertical direction is L1, the total length of the second caisson block in the vertical direction is L2, and the total length of the third caisson block in the vertical direction is L3;

[0008] S3, filling the opening of the side wall of the second caisson block with lattice steel to close the side wall of the second caisson block;

[0009] S4, excavating a foundation pit and placing the first caisson block, the second caisson block and the third caisson block into the foundation pit in sequence.

[0010] Furthermore, prefabricating a plurality of sub-caisson blocks includes prefabricating at least two sub-caisson blocks of different sizes.

[0011] Furthermore, assembling the plurality of sub-caisson blocks into the first caisson block, the second caisson block and the third caisson block comprises: assembling the plurality of sub-caisson blocks into the first caisson block, the second caisson block and the third caisson block, each of which has a segmentation line, wherein the segmentation line is perpendicular to the vertical direction.

[0012] Furthermore, filling the opening of the side wall of the second caisson block with lattice steel includes: connecting a plurality of sub-lattice steels to form the lattice steel, and the block lines between adjacent sub-lattice steels coincide with the segment lines.

[0013] Furthermore, the excavating a foundation pit and placing the plurality of caisson blocks into the foundation pit further comprises:

[0014] S401, excavating a foundation pit to a depth H1, hoisting the first caisson block that has been connected into the foundation pit, wherein the depth H1 is not greater than the total length L1 of the first sub-caisson block in the vertical direction;

[0015] S402, excavating a foundation pit to a depth H2, and hoisting the connected second caisson block into the foundation pit, wherein the depth H2 is equal to the total length L1 of the first caisson block in the vertical direction;

[0016] S403, excavating a foundation pit to a depth of H3, and hoisting the connected third caisson block into the foundation pit, wherein the depth H3 is equal to the sum of the vertical lengths L1 and L2 of the first caisson block connected to the second caisson block;

[0017] S404, excavating a foundation pit to a depth H4, wherein the depth H4 is equal to the sum of the vertical lengths L1, L2 and L3 of the first caisson block connecting the second caisson block and the third caisson block.

[0018] Furthermore, the construction method further comprises:

[0019] S5. dismantling the lattice steel.

[0020] An embodiment of the present invention provides a structure of a working well, and the structure of the working well includes:

[0021] The first caisson block is a hollow body with closed side walls; the second caisson block is a hollow body with open side walls, the second caisson block is located above the first caisson block, and the lower end of the second caisson block is connected to the upper end of the first caisson block; the third caisson block is a hollow body with closed side walls, the third caisson block is located above the second caisson block, the lower end of the third caisson block is connected to the upper end of the second caisson block, and the third caisson is on the same plane as the ground; wherein the side wall opening of the second caisson block is provided with lattice steel, and the lattice steel is used to connect with the side wall of the second caisson block to close the side wall of the second caisson block.

[0022] Furthermore, the lattice steel comprises a plurality of sub-lattice steels connected into one body, and a dividing line is formed between adjacent sub-lattice steels.

[0023] Furthermore, the cross-sectional shape of the side wall opening of the second caisson block is rectangular or circular.

[0024] Furthermore, the first caisson block includes a plurality of first sub-caisson blocks connected as one body, and a first segmentation line is formed between adjacent first sub-caisson blocks; the second caisson block includes a plurality of second sub-caisson blocks, and a second segmentation line is formed between adjacent second sub-caisson blocks; the third caisson block includes a plurality of third sub-caisson blocks, and a third segmentation line is formed between the third sub-caisson blocks; wherein the second segmentation line at least partially overlaps with the segmentation line between the sub-lattice steels.

[0025] The construction method of the working pit provided in the embodiment of the present invention comprises the following steps: S1, prefabricating a plurality of sub-caisson blocks; S2, assembling the plurality of sub-caisson blocks into a first caisson block, a second caisson block and a third caisson block; S3, filling the opening of the side wall of the second caisson block with lattice steel to close the side wall of the second caisson block; S4, excavating a foundation pit and placing the first caisson block, the second caisson block and the third caisson block into the foundation pit in sequence. The structure of the working pit provided in the embodiment of the present invention comprises: a first caisson block, a first caisson block, a third caisson block and lattice steel, the first caisson block and the third caisson block are hollow bodies with closed side walls, and the side wall opening of the second caisson block is provided with lattice steel to close the side wall of the second caisson block. Through the above method and structure, an opening is set on the side wall of the second caisson block, and the opening of the side wall of the second caisson block is filled with lattice steel. During shield or pipe jacking construction, the lattice steel is dismantled in blocks, and the dismantled lattice steel is recycled and reused, thereby reducing the waste of the enclosure structure and the complexity of construction. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0027] Figure 1 It is a schematic flow chart of a construction method of a working pit provided by an embodiment of the present invention;

[0028] Figure 2 It is a schematic flow chart of another working pit construction method provided by an embodiment of the present invention;

[0029] Figure 3It is a schematic flow chart of another method for constructing a working pit provided by an embodiment of the present invention;

[0030] Figure 4 is a schematic cross-sectional view of the structure of a working well provided by an embodiment of the present invention;

[0031] Figure 5 is a top view of a caisson block provided by an embodiment of the present invention;

[0032] Figure 6 is a top view of another caisson block provided by an embodiment of the present invention;

[0033] Figure 7 is a top view of another caisson block provided by an embodiment of the present invention;

[0034] Figure 8 is a structural schematic diagram of a lattice steel provided in an embodiment of the present invention;

[0035] Fig. 9 is a top view of another caisson block provided by an embodiment of the present invention;

[0036] FIG10( a ) is a schematic cross-sectional view of another structure of a working well provided in an embodiment of the present invention;

[0037] FIG10( b ) is a cross-sectional schematic diagram of the structure of another working well provided in an embodiment of the present invention;

[0038] FIG10( c ) is a schematic cross-sectional view of the structure of another working well provided in an embodiment of the present invention;

[0039] Fig.11 is a schematic cross-sectional view of the structure of another working well provided by an embodiment of the present invention;

[0040] Fig.12 is a schematic structural diagram of another lattice steel provided in an embodiment of the present invention;

[0041] Fig.13 is a schematic cross-sectional view of the structure of another working well provided by an embodiment of the present invention;

[0042] Fig.14 It is a schematic cross-sectional view of the structure of another working well provided in an embodiment of the present invention.

[0043] Description of reference numerals:

[0044] 1. Working shaft; 10. Sub-caisson block; 11. First caisson block; 101. First sub-caisson block; 111. Upper end of first caisson block 11; 12. Second caisson block; 102. Second sub-caisson block; 121. Lower end of second caisson block 12; 122. Upper end of second caisson block 12; 13. Third caisson block; 103. Third sub-caisson block; 131. Lower end of third caisson block 13; 132. Upper end of third caisson block 13; 2. Opening; 3. Lattice steel; 301. Sub-lattice steel; 302. Sub-lattice steel of shield tunnel; 31. Bottom plate; 32. Side plate; 321. First side plate; 322. Second side plate; 323. Third side plate; 324. Fourth side plate; 33. Net Grating; 34, cylindrical lattice steel; 341, side of cylindrical lattice steel 34; 4, segmentation line; 41, first segmentation line; 42, second segmentation line; 43, third segmentation line; 5, block line; 6, bolt; 7, tension bolt; L1, total length of the first caisson block 11 in the vertical direction; L2, total length of the second caisson block 12 in the vertical direction; L3, total length of the third caisson block in the vertical direction; L20, wall thickness of the second caisson block 12; D1, distance between bottom plate 31 and grid plate 33; H1, depth of foundation pit excavated in S401; H2, depth of foundation pit excavated in S402; H3, depth of foundation pit excavated in S403; H4, depth of foundation pit excavated in S404. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, 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 intended to limit the present invention.

[0046] The various specific technical features described in the specific embodiments can be combined in any suitable manner without contradiction, for example, different embodiments and technical solutions can be formed by combining different specific technical features. In order to avoid unnecessary repetition, various possible combinations of the specific technical features in the present invention will not be described separately.

[0047] In the following description, the terms "first\second" are only used to distinguish different objects, and do not mean that there is any similarity or connection between the two. It should be understood that the directional descriptions "above", "below", "upper end" and "lower end" are all up and down directions in normal use.

[0048] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0049] An embodiment of the present invention provides a method for constructing a working pit. The construction of the working pit mainly includes excavating a foundation pit, constructing a working pit structure, and sinking the working pit. The working pit constructed by excavating the foundation pit at the beginning and end of the underground tunnel is used as an assembly well and a disassembly well for a shield or a jacking pipe and its equipment. The working pit is connected to the connecting part of the shield or the jacking pipe, and it is necessary to open a hole in the working pit corresponding to the hole of the shield or the jacking pipe to facilitate the construction of the shield or the jacking pipe.

[0050] like Figure 1 As shown, a schematic diagram of a process flow of a working pit construction method provided by an embodiment of the present invention is shown. Figure 4 is a cross-sectional view of a working well structure provided by an embodiment of the present invention; Figure 1 and Figure 4 The steps of a working pit construction method provided by an embodiment of the present invention include:

[0051] Step S1, prefabricate a plurality of sub-caisson blocks 10.

[0052] like Figure 4 As shown, in some embodiments, prefabricated caisson blocks are used to make the working well 1. Due to the limitations of process and transportation tools, the working well 1 is divided into multiple sub-caisson blocks 10 for splicing. It is necessary to prefabricate sub-caisson blocks 10 of a certain size and quantity according to the size of the working well 1, under the premise of meeting the process conditions and transportation tools.

[0053] Step S2, assembling multiple sub-caisson blocks 10 into a first caisson block 11, a second caisson block 12 and a third caisson block 13.

[0054] like Figure 4 and Figure 5 As shown, in some embodiments, the first sub-caisson block 101 and the third sub-caisson block 103 may be hollow bodies with closed side walls. When connected, the first sub-caisson blocks 101 are connected in sequence in the vertical direction to form a first caisson block 11, and the total length of the connected first caisson block 11 in the vertical direction is L1. The third sub-caisson blocks 103 are connected in sequence to form a third caisson block 13, and the total length of the connected third caisson block in the vertical direction is L3.

[0055] like Figure 4and Figure 6 As shown, in some embodiments, the second sub-caisson block 102 is a hollow body with an opening on the side wall. When splicing, the second sub-caisson blocks 102 can be connected in sequence in the vertical direction to form a second caisson block 12 which is a hollow body with an opening on the side wall. The total length of the spliced ​​second caisson block 12 in the vertical direction is L2. The side wall opening 2 of the second caisson block 12 serves as a connection port between the working shaft and the tunnel. By reserving the opening during the prefabrication of the sub-caisson block 10, it is possible to avoid chiseling out the retaining structure at the opening portion of the caisson with a closed side wall, thereby reducing the engineering workload of the retaining structure, simplifying the construction, and improving work efficiency.

[0056] like Figure 7 As shown, in some embodiments, the first sub-caisson block 101 and the third sub-caisson block 103 can be a groove-type structure, which is suitable for a large-sized working well. It is difficult to prepare a hollow body with closed side walls under existing process conditions. Therefore, a groove-type structure can be prepared. The corresponding groove-type structure first sub-caisson block 101 is first connected to form a hollow body with closed side walls, and the corresponding groove-type structure third sub-caisson block 103 is connected to form a hollow body with closed side walls.

[0057] Step S3 , using lattice steel 3 to fill the opening 2 of the side wall of the second caisson block 12 to close the side wall of the second caisson block 12 .

[0058] like Figure 4 As shown, the side wall of the second caisson block 12 has an opening 2. In order to ensure the structural stability of the second caisson block 12, the side wall opening 2 of the second caisson block 12 needs to be filled with lattice steel 3 to close the side wall of the second caisson block 12. In some embodiments, the lattice steel 3 is a structure formed by welding steel plates, the surface of one end of the lattice steel 3 is grid-shaped, and the surface of the other end of the lattice steel 3 is flat and on the same plane as the outer wall of the second caisson block 12.

[0059] Step S4, excavating a foundation pit and placing the first caisson block, the second caisson block and the third caisson block into the foundation pit in sequence.

[0060] In some embodiments, after planning the location of the working pit, after the foundation pit is excavated to a certain depth, some sub-caisson blocks 10 are hoisted into the foundation pit, and then the sub-caisson blocks 10 are sunk by gravity through excavation. The first caisson block 11, the second caisson block 12, and the third caisson block 13 are sequentially placed in the foundation pit. After each caisson block is placed, the foundation pit is excavated to a certain depth, and then the next caisson block is placed, thereby completing the sinking of the working pit.

[0061] In some embodiments, some of the sub-caisson blocks 10 may be hoisted to the planned position of the working pit 1 before excavating the foundation pit. After the foundation pit is excavated to a certain depth, the remaining sub-caisson blocks 10 may be hoisted into the foundation pit, and then the sub-caisson blocks 10 may be sunk by excavation and using their own gravity. The second caisson block 12 and the third caisson block 13 are sequentially placed in the foundation pit. After each caisson block is placed, the foundation pit is excavated to a certain depth, and then the next caisson block is placed, thereby completing the sinking of the working pit.

[0062] For the prefabricated multiple sub-caisson blocks 10, at least two sub-caisson blocks 10 of different sizes need to be prefabricated. In some embodiments, the first caisson block 11 and the third caisson block 13 are hollow bodies with closed side walls. When the process conditions meet the production of an integrated structure, the sub-caisson blocks used to assemble the first caisson block 11 and the third caisson block 13 are prefabricated as hollow bodies with closed side walls. Specifically, the first sub-caisson block 101 and the third sub-caisson block 103 have the same dimensions in cross sections perpendicular to the vertical direction, and the dimensions in the vertical direction may be different. The dimensions in the vertical direction need to be adjusted according to the depth of the working well 1 and the prefabrication process conditions. The second caisson block 12 is a hollow body with an open side wall. The second sub-caisson block 102 used to splice the second caisson block 12 is prefabricated as a hollow body with an open side wall. The shape and size of the second sub-caisson block 102 are adjusted according to the number of openings 3. Figure 6 As shown, in some embodiments, the second caisson block 12 is a hollow body with an opening 2 on the side wall, and the second sub-caisson block 102 is in a "C-shaped" shape, and the second sub-caisson blocks 102 are sequentially connected in the vertical direction to align the openings 2 to form the second caisson block 12. Fig. 9 As shown, in some embodiments, the second caisson block 12 is a hollow body having two openings 2 oppositely arranged on the side wall, and the second sub-caisson block 102 can be a trough-type structure, and the two openings 2 are filled with lattice steel 3 to form the second caisson block 12 by splicing, so that the size of the spliced ​​second caisson block 12 in the cross-sectional size perpendicular to the vertical direction is the same as that of the first caisson block 11 and the third caisson block, so that the inner walls of the first caisson block 11, the second caisson block 12 and the third caisson block 13 are on the same plane.

[0063] In some embodiments, Figure 4 As shown, a plurality of sub-caisson blocks 10 are assembled to form a first caisson block 11, a second caisson block 12 and a third caisson block 13, each of which has a segmentation line 4, and the segmentation line 4 is perpendicular to the vertical direction. In some embodiments, the segmentation line 4 is a dividing line connecting a plurality of sub-caisson blocks 10, and all segmentation lines 4 are perpendicular to the vertical direction, so that the upper end surfaces of the first caisson block 11, the second caisson block 12 and the third caisson block 13 are parallel to their respective lower end surfaces.

[0064] In some embodiments, Figure 4 As shown, filling the opening 2 of the side wall of the second caisson block 12 with the lattice steel 3 includes: connecting a plurality of sub-lattice steels 301 to form the lattice steel 3 , and the block lines 5 and the segment lines 4 between adjacent sub-lattice steels 301 coincide with each other.

[0065] like Figure 8 As shown, in some embodiments, the sub-lattice steel 301 is a structure formed by welding steel plates, and has a bottom plate 31, a side plate 32 and a mesh plate 33. The bottom plate 31 and the side plate 32 form a cavity structure with an opening at the upper end. The side plate 32 includes a first side plate 321, a second side plate 322, a third side plate 323 and a fourth side plate 324. The side plate 32 is arranged on the bottom plate 31, the first side plate 321 and the third side plate 323 are arranged opposite to each other, and the second side plate 322 and the fourth side plate 324 are arranged adjacent to the first side plate 321 and the third side plate 323. The mesh plate 33 is arranged at the upper end of the side plate 32, and is connected to the side plate 32 to fill the opening of the cavity structure.

[0066] like Fig.13 As shown, in some embodiments, the lattice steel 3 includes a plurality of sub-lattice steels 301 connected as one, and a dividing line 5 is formed between adjacent sub-lattice steels 301. In some embodiments, the structure of the sub-lattice steel 301 is consistent with the structure of the lattice steel 3, and the sub-lattice steels 301 are connected by diagonal bolts 7, so that one end of the grid-like surface of the lattice steel 3 is a grid plate 33 of the sub-lattice steel 301. A dividing line 5 is formed between adjacent sub-lattice steels 301, and the dividing line 5 is a dividing line between multiple adjacent sub-lattice steels 301, and the dividing line 5 is perpendicular to the vertical direction.

[0067] like Figure 4 and Figure 8 As shown, in some embodiments, one end of the lattice steel 3 composed of multiple bottom plates 31 and the outer wall of the second caisson block 12 need to be on the same plane, and one end of the lattice steel 3 composed of multiple grid plates 33 and the inner wall of the second caisson block 12 are on the same plane, which can prevent the surrounding soil from entering the working well when the working well 1 sinks, thereby simplifying the construction and increasing the safety of the construction. Then the distance D1 between the bottom plate 31 and the grid plate 33 is equal to the wall thickness L20 of the second caisson block 12.

[0068] like Figure 2 FIG. 1 is a flow chart of another method for constructing a working well according to an embodiment of the present invention, based on Figure 1 , step S4 comprises:

[0069] S401, excavate a foundation pit to a depth of H1, and hoist the first caisson block 11 that has been connected into the foundation pit.

[0070] As shown in FIG. 10( a), in some embodiments, after planning the location of the working well 1, the foundation pit is excavated to a depth H1, so that the depth H1 is not greater than the total length L1 of the first sub-caisson block 13 in the vertical direction, and the connected first caisson block 11 is hoisted into the foundation pit. In some embodiments, some of the sub-caisson blocks 10 may be hoisted to the planned location of the working well 1 before excavating the foundation pit. Since the soil on the inner wall of the first caisson block 11 is excavated, the first caisson block 11 is sunk to just above the horizon by its own weight, completing the sinking of the first caisson block 11.

[0071] S402, excavating a foundation pit to a depth of H2, and hoisting the connected second caisson block 12 into the foundation pit.

[0072] As shown in Figure 10(b), in some embodiments, in step S401, since the upper end of the first caisson block 11 is higher than the ground level, it is necessary to continue to excavate the foundation pit to a depth H2, so that the depth H2 is equal to the total length L1 of the first caisson block 11 in the vertical direction, and then the connected second caisson block 12 is hoisted into the foundation pit and connected to the first caisson block 11.

[0073] S403, excavating a foundation pit to a depth of H3, and hoisting the connected third caisson block into the foundation pit.

[0074] As shown in Figure 10(c), in some embodiments, in step S402, since the upper end of the second caisson block 12 is higher than the ground level, it is necessary to continue to excavate the foundation pit to a depth H3, so that the depth H3 is equal to the sum of the vertical lengths L1 and L2 of the first caisson block 11 connecting the second caisson block 12, and then the connected third caisson block 13 is hoisted into the foundation pit and connected to the second caisson block 12.

[0075] S404. Excavate the foundation pit to a depth of H4.

[0076] like Figure 4 As shown, in some embodiments, in step S403, since the upper end of the third caisson block 13 is higher than the ground level, it is necessary to continue to excavate the foundation pit to a depth H4, so that the depth H4 is equal to the sum of the total lengths L1, L2 and L3 of the first caisson block 11 connecting the second caisson block 12 and the third caisson block 13 in the vertical direction, thereby completing the sinking construction of the working pit.

[0077] like Figure 3 FIG. 1 is a flow chart of another method for constructing a working well according to an embodiment of the present invention, based on Figure 2 , the construction method of the working pit also includes:

[0078] Step S5: dismantling the lattice steel 3.

[0079] like Fig.13As shown, in some embodiments, lattice steel 3 is used to fill the opening 2 of the side wall of the second caisson block 12 to close the side wall of the second caisson block 12. The lattice steel 3 can increase the stability of the structural force of the second caisson block 1 during the assembly process, and can prevent the outer wall soil of the working well 1 from entering the inner wall of the working well 1. The opening 2 of the side wall of the second caisson block 12 is a construction opening reserved for the subsequent tunnel. Before the construction of the subsequent tunnel, the lattice steel 3 needs to be removed. Since the lattice steel 3 is connected by a plurality of sub-lattice steels 301 through tension bolts 7, and the lattice steel 3 is connected to the second caisson block 12 through bolts 6, the lattice steel 3 can be removed in blocks, and the sub-lattice steels 301 can be recycled for reuse.

[0080] An embodiment of the present invention provides a working well, wherein the side wall of the working well has an opening. The working well is constructed by excavating a foundation pit at the beginning and end of an underground tunnel, and can be used as an assembly well and a disassembly well for a shield or a jacking pipe and its equipment. The working well is connected to the connecting part of the shield or the jacking pipe, and a hole needs to be opened at a position corresponding to the hole of the shield or the jacking pipe on the working well to facilitate the construction of the shield or the jacking pipe.

[0081] like Figure 4 As shown, the structure of the working well 1 includes a first caisson block 11, a second caisson block 12, a third caisson block 13 and a lattice steel 3. Since the size of the working well 1 is very large, it needs to be prepared and spliced ​​in blocks. In order to meet the process preparation conditions and facilitate transportation and hoisting, the working well 1 is divided into a first caisson block 11, a second caisson block 12 and a third caisson block 13. The first caisson block is a hollow body with a closed side wall, the second caisson block 12 is a hollow body with an opening 2 on the side wall, and the third caisson block 13 is a hollow body with a closed side wall. The second caisson block 12 is located above the first caisson block 11, and the lower end 121 of the second caisson block 12 is connected to the upper end 111 of the first caisson block. The third caisson block 13 is located above the second caisson block 12, and the lower end 131 of the third caisson block 13 is connected to the upper end 122 of the second caisson block 12, and the upper end 132 of the third caisson block 13 is on the same plane as the ground. Lattice steel 3 is provided at the side wall opening 2 of the second caisson block 12, and the lattice steel 3 is used to connect with the side wall of the second caisson block 12 to close the side wall of the second caisson block 12. The lattice steel 3 and the side wall of the second caisson block 12 can be connected by bolts, which is convenient for installation and disassembly.

[0082] like Figure 4 As shown, in some embodiments, the lattice steel 3 includes a plurality of sub-lattice steels 301 connected together, and a dividing line 5 is formed between adjacent sub-lattice steels 301. Figure 8As shown, in some embodiments, the sub-lattice steel 301 is a structure formed by welding steel plates, and has a bottom plate 31, a side plate 32 and a mesh plate 33. The bottom plate 31 and the side plate 32 form a cavity structure with an opening at the upper end. The side plate 32 includes a first side plate 321, a second side plate 322, a third side plate 323 and a fourth side plate 324. The side plate 32 is arranged on the bottom plate 31, the first side plate 321 and the third side plate 323 are arranged opposite to each other, and the second side plate 322 and the fourth side plate 324 are arranged adjacent to the first side plate 321 and the third side plate 323. The mesh plate 33 is arranged at the upper end of the side plate 32, and is connected to the side plate 32 to fill the opening of the cavity structure.

[0083] like Fig.13 As shown, in some embodiments, the lattice steel 3 includes a plurality of sub-lattice steels 301 connected as one, and a dividing line 5 is formed between adjacent sub-lattice steels 301. In some embodiments, the structure of the sub-lattice steel 301 is consistent with the structure of the lattice steel 3, and the sub-lattice steels 301 are connected by diagonal bolts 7, so that one end of the grid-like surface of the lattice steel 3 is a grid plate 33 of the sub-lattice steel 301. A dividing line 5 is formed between adjacent sub-lattice steels 301, and the dividing line 5 is a dividing line between multiple adjacent sub-lattice steels 301, and the dividing line 5 is perpendicular to the vertical direction.

[0084] like Figure 4 and Figure 8 As shown, in some embodiments, one end of the lattice steel 3 composed of multiple bottom plates 31 and the outer wall of the second caisson block 12 need to be on the same plane, and the other end of the lattice steel 3 composed of multiple grid plates 33 and the inner wall of the second caisson block 12 are on the same plane, which can prevent the surrounding soil from entering the working well when the working well 1 sinks, thereby simplifying the construction and increasing the safety of the construction. Then the distance D1 between the bottom plate 31 and the grid plate 33 is equal to the wall thickness L20 of the second caisson block 12.

[0085] like Figure 4 and Fig.11 As shown, the cross-sectional shape of the side wall opening 2 of the second caisson block 12 is rectangular or circular. Figure 4 As shown, in some embodiments, the opening 2 of the side wall of the second caisson block 12 is a construction opening reserved for a subsequent rectangular jacking tunnel, and the cross-sectional shape of the opening 2 of the side wall of the second caisson block 12 is a rectangle. Fig.11 and Fig.12 As shown, in some embodiments, the opening 21 of the side wall of the second caisson block 12 is a construction opening reserved for the subsequent shield tunnel, and the cross-sectional shape of the side wall opening 21 of the second caisson block 12 is circular. In order to fill the side wall opening 21 of the second caisson block 12, the lattice steel 3 needs to be prepared into a cylinder, so that the side 341 of the cylindrical lattice steel 34 is connected to the side wall opening 21 of the second caisson block 12. Fig.14As shown, in some embodiments, the shield tunnel sub-lattice steel 302 that forms the cylindrical lattice steel 34 needs to be prepared according to the size of the second caisson block 12 and the cylindrical lattice steel 34, the shield tunnel sub-lattice steel 302 is connected by tension bolts 7, and the lattice steel 34 is connected to the second caisson block 12 by bolts 6, so that the lattice steel 34 can be dismantled in blocks, and the shield tunnel sub-lattice steel 302 can be recycled and reused.

[0086] like Figure 4 As shown, the first caisson block 11 includes a plurality of first sub-caisson blocks 101 connected as one, and a first segmentation line 41 is formed between adjacent first sub-caisson blocks 101; the second caisson block 12 includes a plurality of second sub-caisson blocks 102, and a second segmentation line 42 is formed between adjacent second sub-caisson blocks 102; the third caisson block 13 includes a plurality of third sub-caisson blocks 103, and a third segmentation line 43 is formed between the third sub-caisson blocks 103; wherein the second segmentation line 42 of the second caisson block 12 at least partially overlaps with the block line 5 between the sub-lattice steels 301. In some embodiments, since the size of the working well 1 is very large, it needs to be prepared and spliced ​​in blocks. The structure of the working well 1 includes a first caisson block 11, a second caisson block 12 and a third caisson block 13. In order to meet the process preparation conditions and facilitate transportation and lifting, the first caisson block 11 is divided into a plurality of first sub-caisson blocks 101, the second caisson block 12 is divided into a plurality of second sub-caisson blocks 102, and the third caisson block 13 is divided into a plurality of third sub-caisson blocks 103. The first sub-caisson blocks 101 are connected to form a dividing line as a segmentation line 41; the adjacent second sub-caisson blocks 102 are connected to form a dividing line as a segmentation line 42; the third sub-caisson blocks 103 are connected to form a dividing line as a segmentation line 43.

[0087] like Figure 4 As shown, in some embodiments, the first caisson block 11 can be formed by connecting the first sub-caisson blocks 101 in sequence in the vertical direction, and the total length of the first caisson block 11 in the vertical direction after the connection is completed is L1. In some embodiments, the second sub-caisson block 102 is a hollow body with an opening 2 on the side wall, and the second sub-caisson blocks 102 can be connected in sequence in the vertical direction during splicing to form a second caisson block 12 with an opening 2 on the side wall, and the total length of the second caisson block 12 in the vertical direction after the splicing is completed is L2. In some embodiments, the third sub-caisson block 103 can be connected in sequence in the vertical direction to form a third caisson block 13, and the total length of the third caisson block in the vertical direction after the connection is completed is L3. In some embodiments, the first segmentation line 41, the second segmentation line 42 and the third segmentation line 43 are all perpendicular to the vertical direction, and the upper end faces of the first caisson block 11, the second caisson block 12 and the third caisson block 13 are parallel to their respective corresponding lower end faces.

[0088] like Figure 4As shown, in some embodiments, a dividing line 5 is formed between adjacent sub-lattice steels 301 suitable for rectangular jacking tunnels, and the vertical dimension of the sub-lattice steel 301 arranged at the side wall opening 2 of the second caisson block 12 is equal to the vertical dimension of the second sub-caisson block 102, and the second segmentation line 42 of the second caisson block 12 coincides with the dividing line 5 between the sub-lattice steels 301. Fig.11 As shown, in some embodiments, the sub-lattice steel 302 suitable for the shield tunnel forms a dividing line 5 between adjacent ones, and the vertical dimension of the sub-lattice steel 302 of the shield tunnel arranged at the side wall opening 21 of the second caisson block 12 is equal to the vertical dimension of the second sub-caisson block 102, and the second segmentation line 42 of the second caisson block 12 coincides with the dividing line 5 between the sub-lattice steel 302 of the shield tunnel.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for a working pit, characterized in that: The following steps are involved: S1, prefabricate multiple sub-caisson blocks; S2, assembling the plurality of sub-caisson blocks into a first caisson block, a second caisson block and a third caisson block; wherein the first caisson block and the third caisson block are hollow bodies with closed side walls; the second caisson block is a hollow body with open side walls; the total length of the first caisson block in the vertical direction is L1, the total length of the second caisson block in the vertical direction is L2, and the total length of the third caisson block in the vertical direction is L3; S3, filling the opening of the side wall of the second caisson block with lattice steel to close the side wall of the second caisson block; S4, excavating a foundation pit and placing the first caisson block, the second caisson block and the third caisson block into the foundation pit in sequence; S5, dismantling the lattice steel to construct the tunnel from the side wall opening of the second caisson block; S6. Recovering the lattice steel.

2. The construction method according to claim 1, characterized in that: Prefabricating a plurality of sub-caisson blocks includes prefabricating at least two sub-caisson blocks of different sizes.

3. The construction method according to claim 1, characterized in that: Assembling the plurality of sub-caisson blocks into the first caisson block, the second caisson block and the third caisson block comprises: assembling the plurality of sub-caisson blocks into the first caisson block, the second caisson block and the third caisson block, each of which has a segmentation line, wherein the segmentation line is perpendicular to the vertical direction.

4. The construction method according to claim 3, characterized in that: Filling the opening of the side wall of the second caisson block with lattice steel includes: connecting a plurality of sub-lattice steels to form the lattice steel, and the block lines between adjacent sub-lattice steels coincide with the segment lines.

5. The construction method according to claim 1, characterized in that: The excavating of the foundation pit and sequentially placing the first caisson block, the second caisson block and the third caisson block into the foundation pit further comprises: S401, excavating a foundation pit to a depth H1, hoisting the first caisson block that has been connected into the foundation pit, wherein the depth H1 is not greater than a total length L1 of the first caisson block in the vertical direction; S402, excavating a foundation pit to a depth H2, and hoisting the connected second caisson block into the foundation pit, wherein the depth H2 is equal to the total length L1 of the first caisson block in the vertical direction; S403, excavating a foundation pit to a depth of H3, and hoisting the connected third caisson block into the foundation pit, wherein the depth H3 is equal to the sum of the vertical lengths L1 and L2 of the first caisson block connected to the second caisson block; S404, excavating a foundation pit to a depth H4, wherein the depth H4 is equal to the sum of the vertical lengths L1, L2 and L3 of the first caisson block connecting the second caisson block and the third caisson block.

6. A working well structure, characterized in that: include: The first caisson block is a hollow body with closed side walls; The second caisson block is a hollow body with an open side wall, the second caisson block is located above the first caisson block, and the lower end of the second caisson block is connected to the upper end of the first caisson block; The third caisson block is a hollow body with closed side walls, the third caisson block is located above the second caisson block, the lower end of the third caisson block is connected to the upper end of the second caisson block, and the third caisson block is on the same plane as the ground plane; Wherein, the side wall opening of the second caisson block is provided with lattice steel, the lattice steel is used to be connected with the side wall of the second caisson block to close the side wall of the second caisson block, and the lattice steel is connected to the side wall of the second caisson block by bolts; The lattice steel comprises a plurality of sub-lattice steels connected as one, and a dividing line is formed between adjacent sub-lattice steels. The lattice steel can be dismantled in blocks, and the sub-lattice steels can be recycled and reused. The cross-sectional shape of the side wall opening of the second caisson block is rectangular or circular.

7. The working well structure according to claim 6, characterized in that: The first caisson block includes a plurality of first sub-caisson blocks connected as one, and a first segmentation line is formed between adjacent first sub-caisson blocks; The second caisson block includes a plurality of second sub-caisson blocks, and a second segmentation line is formed between adjacent second sub-caisson blocks; The third caisson block includes a plurality of third sub-caisson blocks, and a third segmentation line is formed between the third sub-caisson blocks; Wherein, the second segmentation line at least partially coincides with the block lines between the sub-lattice steels.

Images