A rigid bottom sealing structure of a mother-and-child steel pipe group and a construction method thereof

Abstract

The present invention provides a rigid bottom sealing structure of a mother-and-child steel pipe group and a construction method, including a wavy mother-and-child steel pipe group; the wavy mother-and-child steel pipe group is composed of a plurality of mother-and-child steel pipe groups connected in sequence, and the cross section of the wavy mother-and-child steel pipe group is a wavy shape formed by connecting a plurality of arcs; the mother-and-child steel pipe group is composed of a mother pipe and a child pipe connected transversely, and concrete is poured in the mother pipe and the child pipe; the underground continuous wall of the starting well and the underground continuous wall of the receiving well are connected by two rows of main underground continuous walls, and the two rows of main underground continuous walls are respectively connected to the two sides of the wavy mother-and-child steel pipe group; the bottom of the structural column of the main structure is connected to the wavy mother-and-child steel pipe group; the two ends of the wavy mother-and-child steel pipe group are respectively located in the starting well and the receiving well, and concrete is backfilled between the bottom of the starting well and the receiving well and the main structure. The present invention greatly improves the reliability of the bottom sealing, effectively saves the construction period, greatly reduces the project cost, and avoids the shortcomings of large-area water seepage and water leakage of conventional bottom sealing structures.

Description

Technical Field

[0001] The invention belongs to the technical field of underground engineering, and particularly relates to a rigid bottom sealing structure of a mother-and-child steel pipe group and a construction method. Background Art

[0002] In underground projects, with the increasing scarcity of shallow underground space, more and more high-water levels, ultra-deep dark or open underground structures are appearing. At present, for such projects, the main method is to arrange enough precipitation wells for precipitation construction. However, the capacity of municipal drainage facilities is limited, especially the large-scale pumping of groundwater, which causes groundwater waste and is not conducive to the protection of groundwater resources. With increasingly stringent environmental protection requirements, more and more ultra-deep underground structures require water-stopping construction to save underground resources, among which the bottom groundwater plugging is the key and difficult point. In the existing technology, rotary jetting, ultra-high pressure rotary jetting, and freezing methods are mainly used for plugging construction. Especially for deeper underground structures, the quality of the existing technology is difficult to guarantee, and there is a risk of leakage. The common characteristics are thick plugging structure, huge engineering volume, high cost, poor effect, and great safety hazards. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a rigid bottom sealing structure and construction method of a mother-and-child steel pipe group, which overcomes the many disadvantages of the prior art such as high cost, poor effect and many safety hazards, and improves the reliability and safety of the bottom sealing.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present invention provides a rigid bottom sealing structure of a mother-and-child steel pipe group, including a corrugated mother-and-child steel pipe group;

[0006] The wavy mother-and-child steel pipe group is composed of a plurality of mother-and-child steel pipe groups connected transversely in sequence, and the cross section of the wavy mother-and-child steel pipe group is a wavy shape formed by connecting a plurality of arcs; the mother-and-child steel pipe group is composed of a mother pipe and a child pipe connected transversely, the diameter of the mother pipe is larger than the diameter of the child pipe, and concrete is poured in the mother pipe and the child pipe;

[0007] The underground continuous wall of the starting well and the underground continuous wall of the receiving well are connected by two rows of main underground continuous walls, and the two rows of main underground continuous walls are respectively connected to the two sides of the wavy mother-and-child steel pipe group; a main structure is arranged above the wavy mother-and-child steel pipe group, and the bottom of the structural column of the main structure is connected to the wavy mother-and-child steel pipe group; the two ends of the wavy mother-and-child steel pipe group are respectively located in the starting well and the receiving well, and concrete is backfilled between the bottom of the starting well and the receiving well and the main structure.

[0008] Preferably, the wavy mother-and-child steel pipe group is composed of several mother-and-child steel pipe groups connected by T-shaped waterproof locks, the T-shaped waterproof locks include lock sealing plates, flange plates, and circular water stop strips, the outer wall of the mother pipe in the mother-and-child steel pipe group is connected with a flange plate, the flange plate passes through the outer wall of one side of the child pipe in the adjacent mother-and-child steel pipe group, and the end of the flange plate is connected with a lock sealing plate perpendicular to the flange plate, the lock sealing plate is located in the child pipe cavity, and circular water stop strips are respectively provided on the upper and lower surfaces of the flange plate located in the child pipe cavity.

[0009] Preferably, the two sides of the corrugated mother-and-child steel pipe group are respectively connected to the two rows of main underground continuous walls through underground continuous wall connecting flange plates; the underground continuous wall connecting flange plates are fixedly connected to the mother pipes on both sides of the corrugated mother-and-child steel pipe group.

[0010] Preferably, the main underground continuous wall is provided with a groove which cooperates with the flange plate connecting the underground continuous wall, the depth of the groove is not greater than 0.3 times the thickness of the main underground continuous wall, and a water stop strip is reserved in the groove.

[0011] Preferably, the diameter of the main pipe is 1 to 2 m, and the diameter of the sub-pipe is 150 mm.

[0012] In a second aspect, the present invention further provides a method for constructing a rigid bottom sealing structure of a mother-and-child steel pipe group, the method comprising the following steps:

[0013] Step S1, constructing an underground continuous wall of a starting well, an underground continuous wall of a receiving well, and an underground continuous wall of a main body;

[0014] Step S2, excavating a starting well and a receiving well, and setting up several foundation pit supports;

[0015] Step S3, using the starting well as the construction surface, jacking the mother-and-child steel pipe group to the receiving well in sections by a small-sized pipe jacking machine, connecting several mother-and-child steel pipe groups into a wavy mother-and-child steel pipe group by a T-shaped waterproof lock, and the two ends of the wavy mother-and-child steel pipe group are respectively located in the starting well and the receiving well;

[0016] Step S4, reserving structural column reinforcement in the mother tube below the structural column of the main structure, and pouring concrete 1 in the mother tube and the child tube; then backfilling concrete 2;

[0017] Step S5, excavating the foundation pit and constructing the underground main structure; the structural columns of the main structure are connected to the corrugated mother-and-child steel pipe group through the structural column steel bars reserved in the mother pipe below it.

[0018] Preferably, the underground continuous wall of the starting well, the underground continuous wall of the receiving well and the main underground continuous wall are C40 reinforced concrete structures; the main underground continuous wall is connected to the wavy mother-and-child steel pipe group through the underground continuous wall connecting flange plate, and no less than two grooves with a length and height of 30cm×30cm are reserved in the lower part of the main underground continuous wall to reserve insertion space for the underground continuous wall connecting flange plate.

[0019] Preferably, in step S2, closed dewatering wells are arranged in advance in the starting well and the receiving well to carry out pressure reduction and dewatering to a safe water level for the foundation pit to resist sudden surges.

[0020] Preferably, the specific steps of step S5 are:

[0021] (1) Excavation of earthwork above the water level to a point 0.5 m above the water level;

[0022] (2) Drainage and excavation of the pit below the water level; a temporary drainage well is set up in the foundation pit, and the drained soil is vertically transported out using vertical lifting equipment, and the foundation pit is cleaned;

[0023] (3) Lay waterproofing, construct the base plate, structural columns, side walls, and top plate of the main structure from bottom to top, complete the structural closure, and finally construct the internal structure, carry out building masonry and decoration to complete the station construction.

[0024] The present invention has the following beneficial effects:

[0025] The present invention provides a rigid bottom sealing structure and construction method of a mother-and-child steel pipe group. A mechanical method is used to construct large-diameter mother-and-child steel pipes to form a plurality of arc structures, and finally a wavy mother-and-child steel pipe group rigid bottom sealing structure is formed, which effectively improves the construction efficiency and construction quality, and avoids the shortcomings of large-area water seepage and water leakage of conventional bottom sealing structures; the arc structure is used to improve the stress of the bottom sealing structure, and the thickness of the bottom sealing is effectively reduced; the bottom sealing structure of the wavy mother-and-child steel pipe group, the structural column, the main underground continuous wall, the underground continuous wall of the starting well, the underground continuous wall of the receiving well, the starting well and the receiving well are rigidly connected, and finally an overall anti-floating structure is formed, and auxiliary anti-floating measures such as anti-pull piles can be eliminated. Finally, the wavy mother-and-child steel pipe group rigid bottom sealing structure of the present invention greatly improves the reliability of the bottom sealing, effectively saves the construction period, greatly reduces the project cost, effectively protects the groundwater resources, and truly realizes the design concept of safety and environmental protection requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the embodiments of the present invention.

[0027] Figure 1 It is a schematic diagram of the engineering plane of an embodiment of the present invention;

[0028] Figure 2 It is a schematic cross-sectional view of a foundation pit in an embodiment of the present invention;

[0029] Figure 3 This is a schematic cross-sectional view of a launching well / receiving well in an embodiment of the present invention;

[0030] Figure 4 This is a force diagram of the bottom cover structure of the mother-and-child steel pipe group according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the connection between the corrugated mother-and-child steel pipe group and the main underground continuous wall in an embodiment of the present invention;

[0032] Figure 6 This is a schematic diagram of a mother-and-child steel pipe assembly in an embodiment of the present invention;

[0033] Figure 7 This is a schematic diagram of a reserved groove for the main underground continuous wall in an embodiment of the present invention;

[0034] Figure 8 Schematic diagram of a T-shaped waterproof lock buckle in an embodiment of the present invention;

[0035] Fig. 9 It is a schematic diagram of the anti-floating structure under the structural column in an embodiment of the present invention.

[0036] Description of reference numerals:

[0037] 10. Starting shaft; 20. Receiving shaft; 30. Main underground continuous wall; 31. Starting shaft underground continuous wall; 32. Receiving shaft underground continuous wall; 33. Channel; 40. Wave-shaped mother-and-child steel pipe group; 41. Mother pipe; 42. Child pipe; 43. Locking plate; 44. Flange plate; 45. Circular water stop strip; 46. Underground continuous wall connecting flange plate; 47. Concrete one; 50. Main structure; 51. Foundation pit support; 52. Structural column; 53. Concrete two; 54. Structural column reinforcement. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0039] This embodiment provides a rigid bottom sealing structure of a mother-and-child steel pipe group, such as Figures 1 to 9As shown, it includes a wavy mother-and-child steel pipe group 40; the wavy mother-and-child steel pipe group 40 is composed of a plurality of mother-and-child steel pipe groups connected transversely in sequence through T-shaped waterproof lock buckles, and the cross section of the wavy mother-and-child steel pipe group 40 is a wavy shape formed by connecting a plurality of arcs; the mother-and-child steel pipe group is composed of a mother pipe 41 and a child pipe 42 connected transversely, and the diameter of the mother pipe 41 is larger than the diameter of the child pipe 42, preferably the diameter of the mother pipe 41 is 1 to 2m, and the diameter of the child pipe 42 is 150mm. Concrete 47 is poured in the mother pipe 41 and the child pipe 42.

[0040] The underground continuous wall 31 of the starting well arranged at the periphery of the starting well 10 and the underground continuous wall 32 of the receiving well arranged at the periphery of the receiving well 20 are connected by two rows of main underground continuous walls 30, and the two rows of main underground continuous walls 30 are respectively connected to the two sides of the wavy mother-and-child steel pipe group 40; a main structure 50 is arranged above the wavy mother-and-child steel pipe group 40, and the bottom of the structural column 52 of the main structure 50 is connected to the wavy mother-and-child steel pipe group 40; the two ends of the wavy mother-and-child steel pipe group 40 are respectively located in the starting well 10 and the receiving well 20, and concrete 53 is backfilled between the bottom of the starting well 10 and the receiving well 20 and the main structure 50.

[0041] like Figures 5 to 8 As shown, the T-shaped waterproof lock includes a lock plate 43, a flange plate 44, and a circular water stop strip 45. The outer wall of the mother pipe 41 in the mother-and-child steel pipe group is connected with a flange plate 44. The flange plate 44 passes through the outer wall of one side of the child pipe 42 in the adjacent mother-and-child steel pipe group, and the end of the flange plate 44 is connected with a lock plate 43 perpendicular to the flange plate 44. The lock plate 43 is located in the cavity of the child pipe 42, and the upper and lower surfaces of the flange plate 44 located in the cavity of the child pipe 42 are respectively provided with circular water stop strips 45. The lock plate 43 and the flange plate 44 can be welded, as long as the force and structural requirements are met. When groundwater flows into the mother pipe 41 from the joint of the mother-and-child pipe group, the circular water stop strip 45 expands when it encounters water to form a good water stop body. The number of circular water stop strips 45 can be finally determined based on the experimental results. The two sides of the wavy mother-and-child steel pipe group 40 are respectively connected to the two rows of main underground continuous walls 30 through underground continuous wall connecting flange plates 46; the underground continuous wall connecting flange plates 46 are fixedly connected to the mother pipes 41 on both sides of the wavy mother-and-child steel pipe group 40, and the child pipe 42 is omitted in the outermost mother-and-child steel pipe group on one side of the wavy mother-and-child steel pipe group 40.

[0042] The two sides of the wavy steel tube group 40 are connected to the main underground continuous wall 30 through the mother tube 41, and the mother tube 41 on each side is connected to the main underground continuous wall 30 through no less than two underground continuous wall connecting flange plates 46. The main underground continuous wall 30 is reserved with a groove 33 that cooperates with the underground continuous wall connecting flange plate 46, the depth of the groove 33 is not more than 0.3 times the thickness of the main underground continuous wall 30, and a water stop strip is reserved in the groove 33.

[0043] like Figure 4 As shown in the figure, the corrugated steel tube group bottom sealing structure is acted upon by buoyancy F and the upper soil and self-weight G. The buoyancy force F produces two components, a horizontal component F1 and a vertical upward component F2. The vertical downward gravity G produced by the corrugated steel tube group and the soil above prevents the vertical upward buoyancy component F2. Among them, F2 is smaller than the total buoyancy F. Therefore, the corrugated steel tube group bottom sealing greatly improves the force and can replace the conventional large-volume concrete bottom sealing method.

[0044] This embodiment also provides a method for constructing a rigid bottom sealing structure of a mother-and-child steel pipe group. Figures 1 to 9 As shown, the method comprises the following steps:

[0045] Step S1, constructing the underground continuous wall 31 of the starting well, the underground continuous wall 32 of the receiving well, and the main underground continuous wall 30;

[0046] Step S2, excavating the starting well 10 and the receiving well 20, and setting up several foundation pit supports 51;

[0047] Step S3, using the starting well 10 as the construction surface, and using a small jacking machine to push the mother-and-child steel pipe group into the receiving well 20 in sections, and connecting several mother-and-child steel pipe groups into a wavy mother-and-child steel pipe group 40 through a T-shaped waterproof lock, and the two ends of the wavy mother-and-child steel pipe group 40 are respectively located in the starting well 10 and the receiving well 20; the clearance dimensions of the starting well 10 and the receiving well 20 need to be determined according to the mother-and-child steel pipe group jacking equipment and the construction clearance requirements.

[0048] Step S4, a structural column steel bar 54 is reserved in the mother tube 41 below the structural column 52 of the main structure 50, and concrete 1 47 is poured in the mother tube 41 and the child tube 42; then backfilling concrete 2 53 is constructed;

[0049] Step S5, excavate the foundation pit and construct the underground main structure 50; the structural column 52 of the main structure 50 is connected to the corrugated mother-and-child steel pipe group 40 through the structural column steel bars 54 reserved in the mother pipe 41 below it. After the reserved structural column steel bars 54 are poured with concrete, they are integrated with the structural columns 52, and finally the main structure, the corrugated mother-and-child steel pipe bottom sealing structure and the soil above the bottom sealing, the underground continuous wall 31 of the launch well, the underground continuous wall 32 of the receiving well, and the main underground continuous wall 30 form an integral anti-floating structure, and no anti-pullout piles are required.

[0050] Furthermore, the underground continuous wall 31 of the starting well, the underground continuous wall 32 of the receiving well, and the main underground continuous wall 30 are C40 reinforced concrete structures; the main underground continuous wall 30 is connected to the wavy mother-and-child steel pipe group 40 through the underground continuous wall connecting flange plate 46, and no less than two grooves 33 with a length and height of 30cm×30cm are reserved at the lower part of the main underground continuous wall 30 to reserve insertion space for the underground continuous wall connecting flange plate 46.

[0051] Furthermore, in step S2, closed dewatering wells are arranged in advance in the starting well 10 and the receiving well 20 to reduce pressure and dewater to a safe water level for the foundation pit to resist sudden surges.

[0052] Furthermore, the specific steps of step S5 are:

[0053] (1) Excavation above the water level should be carried out to a point 0.5 m above the water level.

[0054] (2) Drainage and excavation of the pit below the water level; a temporary drainage well is set up in the foundation pit, and the drained soil is vertically transported out using vertical lifting equipment, and the foundation pit is cleaned.

[0055] (3) Lay waterproofing, construct the base plate, structural columns, side walls, and top plate of the main structure 50 from bottom to top, complete the structural closure, and finally construct the internal structure, carry out building masonry and decoration to complete the station construction.

[0056] Since the bottom sealing structure of the wavy mother-and-child steel pipe group is a rigid water-stopping structure, it is combined with the main underground continuous wall, the starting well underground continuous wall, and the receiving well underground continuous wall to form a closed water-stopping structure, which increases the anti-buoyancy ability, improves the bottom sealing force, effectively reduces the bottom sealing thickness, and greatly avoids underwater excavation.

[0057] The above embodiments of the present invention are described in detail through examples, but the contents described are only exemplary embodiments of the embodiments of the present invention and cannot be considered to limit the scope of implementation of the embodiments of the present invention. The protection scope of the embodiments of the present invention is defined by the claims. Anyone who utilizes the technical solutions described in the embodiments of the present invention, or who, inspired by the technical solutions of the embodiments of the present invention, designs similar technical solutions within the essence and protection scope of the embodiments of the present invention to achieve the above technical effects, or who makes equal changes and improvements to the scope of application, shall still fall within the scope of protection covered by the patent of the embodiments of the present invention.

Claims

1. A rigid bottom sealing structure of a mother-and-child steel pipe group, characterized in that: It includes a group of corrugated steel tubes (40); The wavy mother-and-child steel pipe group (40) is composed of a plurality of mother-and-child steel pipe groups connected in sequence, and the cross section of the wavy mother-and-child steel pipe group (40) is a wavy shape formed by connecting a plurality of arcs; the mother-and-child steel pipe group is composed of a mother pipe (41) and a child pipe (42) connected transversely, the diameter of the mother pipe (41) is larger than the diameter of the child pipe (42), and concrete (47) is poured in the mother pipe (41) and the child pipe (42); The underground continuous wall (31) of the launching well and the underground continuous wall (32) of the receiving well are connected by two rows of main underground continuous walls (30), and the two rows of main underground continuous walls (30) are respectively connected to the two sides of the wavy mother-and-child steel pipe group (40); a main structure (50) is arranged above the wavy mother-and-child steel pipe group (40), and the bottom of the structural column (52) of the main structure (50) is connected to the wavy mother-and-child steel pipe group (40); the two ends of the wavy mother-and-child steel pipe group (40) are respectively located in the launching well (10) and the receiving well (20), and concrete (53) is backfilled between the bottom of the launching well (10) and the receiving well (20) and the main structure (50); The wavy mother-and-child steel pipe group (40) is composed of a plurality of mother-and-child steel pipe groups connected by a T-shaped waterproof lock buckle, wherein the T-shaped waterproof lock buckle comprises a lock buckle sealing plate (43), a flange plate (44), and a circular water stop strip (45); the outer wall of the mother pipe (41) in the mother-and-child steel pipe group is connected to the flange plate (44); the flange plate (44) passes through the outer wall of one side of the child pipe (42) in the adjacent mother-and-child steel pipe group, and the end of the flange plate (44) is connected to a lock buckle sealing plate (43) perpendicular to the flange plate (44); the lock buckle sealing plate (43) is located in the cavity of the child pipe (42); and the upper and lower surfaces of the flange plate (44) located in the cavity of the child pipe (42) are respectively provided with circular water stop strips (45); The two sides of the wavy mother-and-child steel pipe group (40) are respectively connected to two rows of main underground continuous walls (30) via underground continuous wall connecting flange plates (46); the underground continuous wall connecting flange plates (46) are fixedly connected to the mother pipes (41) on both sides of the wavy mother-and-child steel pipe group (40); The main underground continuous wall (30) is reserved with a groove (33) that cooperates with the underground continuous wall connecting flange plate (46), the depth of the groove (33) is not greater than 0.3 times the thickness of the main underground continuous wall (30), and a water stop strip is reserved in the groove (33); The diameter of the main pipe (41) is 1 to 2 m, and the diameter of the sub-pipe (42) is 150 mm.

2. A construction method for the rigid bottom sealing structure of the mother-and-child steel pipe group according to claim 1, characterized in that: The method comprises the following steps: Step S1, constructing an underground continuous wall (31) of the starting well, an underground continuous wall (32) of the receiving well, and a main underground continuous wall (30); Step S2, excavating a starting well (10) and a receiving well (20), and setting up several foundation pit supports (51); Step S3, using the starting well (10) as a construction surface, jacking the mother-and-child steel pipe groups into the receiving well (20) in sections by means of a small-sized pipe jacking machine, connecting a plurality of the mother-and-child steel pipe groups into a wavy mother-and-child steel pipe group (40), wherein the two ends of the wavy mother-and-child steel pipe group (40) are respectively located in the starting well (10) and the receiving well (20); Step S4, reserving structural column reinforcement (54) in the mother tube (41) below the structural column (52) of the main structure (50), and pouring concrete one (47) in the mother tube (41) and the child tube (42); and then backfilling concrete two (53); Step S5, excavating a foundation pit and constructing an underground main structure (50); the structural columns (52) of the main structure (50) are connected to the corrugated mother-and-child steel pipe group (40) through the structural column steel bars (54) reserved in the mother pipe (41) below the main structure (50); The underground continuous wall (31) of the starting well, the underground continuous wall (32) of the receiving well, and the main underground continuous wall (30) are C40 reinforced concrete structures; the main underground continuous wall (30) is connected to the wave-shaped mother-and-child steel pipe group (40) through an underground continuous wall connecting flange plate (46); at least two grooves (33) with a length and height of 30 cm×30 cm are reserved at the lower part of the main underground continuous wall (30) to reserve insertion space for the underground continuous wall connecting flange plate (46); In step S2, closed dewatering wells are arranged in advance in the starting well (10) and the receiving well (20) to reduce pressure and dewater to a safe water level for the foundation pit to resist sudden surges.

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