A foundation pit retaining structure and construction method thereof

Abstract

The invention discloses a foundation pit retaining structure and a construction method thereof, which belongs to the technical field of building construction. By arranging a plurality of spliced ​​steel pipes, the steel pipe structure is made more convenient and quick in the subsequent dismantling and recycling process. A casting pipe cone is slidably arranged in the spliced ​​steel pipe, and the casting pipe cone slides into the excavated hole through the spliced ​​steel pipe and solidifies into one with the casting pipe cone, so that the oblique steel pipe structure effectively supports the crown beam. The casting pipe cone structure is convenient for pre-digging the excavated hole by arranging a structure setting in which the internal sliding enters the excavated hole, and after the steel pipes are spliced ​​in sequence, the casting pipe cone is extended into the excavated hole. After the concrete is poured, the retaining structure forms an effective supporting structure. Compared with pouring first and then splicing, this structure can effectively avoid the problem of changing the oblique support angle or different oblique support lengths caused by the steel pipe splicing error caused by the fixed pouring position after pouring, thereby saving the time of waiting for the concrete to solidify.

Description

Technical Field

[0001] The invention belongs to the technical field of building construction, and particularly relates to a foundation pit retaining structure and a construction method thereof. Background Art

[0002] The purpose of the pit retaining structure is to ensure the safety and stability of the pit project, as well as to protect the safety of the surrounding environment and buildings. In the central area of ​​the city, due to the dense buildings, the depth of the pit excavation and the complexity of the surrounding environmental conditions, the safety requirements for the retaining structure are higher. The pit retaining system is a system of interaction between the soil and the supporting structure. It not only ensures the stability of the pit and the safety of the pit operation, but also controls the displacement of the pit bottom and the soil outside the pit to ensure the normal use of adjacent buildings and municipal facilities.

[0003] The commonly installed foundation pit retaining structure is a diagonal braced steel pipe structure that is obliquely supported on the side surface of the foundation pit. This structure supports the side surface of the foundation pit by supporting one end of the steel pipe on the crossbeam on the side surface of the foundation pit and the other end inside the foundation pit. When installing this steel pipe, it is necessary to cast a supporting structure on the ground, and then connect the steel pipes between the crossbeam and the cast supporting structure in sequence. This installation structure has high requirements on precision and low installation efficiency. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a foundation pit retaining structure and a construction method thereof to ensure installation accuracy and improve installation efficiency.

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

[0006] A foundation pit retaining structure comprises a plurality of columns arranged on the side surface of the foundation pit and crown beams supported and connected by the plurality of columns, the outer side of the crown beam is fixedly connected to a steel pipe seat, the steel pipe seat is connected in turn with a plurality of spliced ​​steel pipes, the spliced ​​steel pipe extends obliquely downward, a casting pipe cone is slidably arranged inside the spliced ​​steel pipe, the upper end of the casting pipe cone is closed, the lower end is a pointed structure with an internal hollow, and a plurality of casting holes are arranged at the lower end of the casting pipe cone; it also comprises a dug hole opened in the supported ground, the casting pipe cone moves along the spliced ​​steel pipe into the dug hole, a plurality of insertion holes arranged around the casting pipe cone are arranged at the upper end of the casting pipe cone, a stopper is inserted into the insertion hole, and the stopper is fixedly connected to the end of the steel pipe so that the casting pipe cone is fixed at the end of the spliced ​​steel pipe.

[0007] Furthermore, two retaining rings are fixedly provided in the middle section of the spliced ​​steel pipe at the end, and a plurality of hydraulic cylinders are provided between the retaining rings. The output ends of the hydraulic cylinders extend obliquely toward the ground and also include a plurality of push blocks. The push blocks are inserted into one of the casting holes away from the casting pipe cone. The output ends of the hydraulic cylinders are against the push blocks, and the hydraulic cylinders push the push blocks to insert the casting pipe cone into the soil at the bottom of the excavated hole.

[0008] Furthermore, a supporting foot is extended from the outer end of the push block, and the supporting foot extends into the side wall of the excavated hole. The width of the push block along the extension direction of the casting tube cone is smaller than the casting hole. A countersunk hole is provided in the closed end of the casting tube cone along the extension direction of the casting tube cone. A support column is slidably provided in the countersunk hole, and a baffle is provided at the end of the support column. The baffle is blocked on the upper side of the push block extending into the casting tube cone. The ground section of the casting tube cone is also threadedly connected with a threaded baffle column, and the threaded baffle column is blocked at the end of the support column. When the threaded baffle column is removed, the support column slides along the countersunk hole to the bottom of the countersunk hole, and the push block rotates around the casting hole under the support of the hydraulic cylinder, so that the supporting foot is in an inclined state on the side wall of the excavated hole.

[0009] Furthermore, a through hole is penetrated through the closed end of the casting cone, and a hose is connected to the through hole. The hose extends from the upper end of the casting cone along the spliced ​​steel pipe to the top of the crown beam. A cement pump is provided at the top of the crown beam, and the cement pump transports concrete into the casting cone through the hose.

[0010] Furthermore, it also includes a fixing rod, and the end of the spliced ​​steel pipe at the end is also provided with a blocking structure, the fixing rod passes through the blocking structure and abuts against the push block, the output end of the hydraulic cylinder is in contact and connected with the upper end of the fixing rod, and the upper end of the fixing rod is also threadedly connected with a locking nut. After the insertion of the casting pipe cone is completed, the locking nut moves along the fixing rod and abuts against the blocking structure.

[0011] A construction method for foundation pit enclosure, the steps of which are as follows:

[0012] S1. When constructing the foundation pit, cast construction columns and crown beams on the side surface of the foundation pit, and make oblique holes on the crown beams;

[0013] S2. Pre-drill holes for pouring concrete at the ground support position of the foundation pit. The hole positions are preliminarily determined based on the length of the oblique support steel pipe and the height of the crown beam;

[0014] S3. Install a steel pipe seat and several spliced ​​steel pipes in sequence at the oblique opening position of the side wall of the crown beam, and place the casting pipe cone into the spliced ​​steel pipe along the oblique opening on the top side of the crown beam;

[0015] S4. After the casting steel pipe falls into the dug hole along the spliced ​​steel pipe, a hydraulic cylinder is installed between the two retaining rings at the end of the spliced ​​steel pipe, a fixing rod is installed at the retaining structure, and a supporting foot is inserted into the casting hole of the casting steel pipe;

[0016] S5, the hydraulic cylinder works to push the casting steel pipe into the bottom surface of the dug hole until the insertion hole of the casting steel pipe leaks out, inserts a stopper into the insertion hole, and fixes the stopper at the end of the spliced ​​steel pipe;

[0017] S6. Remove the threaded stop column, and the hydraulic cylinder continues to work, so that the support foot is obliquely inserted into the side wall of the hole, and then the locking nut is fixed and the hydraulic cylinder is removed;

[0018] S7. Install a cement pump on the top of the crown beam and fill the concrete into the casting steel pipe through the hose of the cement pump until the concrete fills the excavated hole.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a support bracket for the side surface of the foundation pit by setting a crown beam and a column structure, and then further improves the stability of the foundation pit enclosure structure by setting an obliquely supported steel pipe structure. In this structure, by setting a plurality of spliced ​​steel pipes, the steel pipe structure is more convenient and quick in the subsequent dismantling and recycling process. A pouring pipe cone is slidably set in the spliced ​​steel pipe, and the pouring pipe cone slides into the dug hole through the spliced ​​steel pipe. The dug hole is used for pouring concrete, and the concrete is solidified into one with the pouring pipe cone, so that the oblique steel pipe structure effectively supports the crown beam. This pouring The pipe-cone structure is convenient for pre-excavation of the hole by setting up a structural setting for sliding inside to enter the hole. After splicing the steel pipes in sequence, the pouring pipe cone is extended into the hole. After pouring the concrete, this enclosure structure forms an effective supporting structure. Compared with pouring first and then splicing, this structure can effectively avoid the problem of changes in the oblique support angle or different oblique support lengths caused by the steel pipe splicing error caused by the fixed pouring position after pouring, saving the time waiting for the concrete to solidify. This structure improves the steel pipe support effect and is fast in construction.

[0021] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0023] Figure 1 It is an overall schematic diagram of the foundation pit retaining structure according to an embodiment of the present invention;

[0024] Figure 2 for Figure 1 A magnified schematic diagram of point A;

[0025] Figure 3 It is a cross-sectional view of a foundation pit retaining structure according to an embodiment of the present invention;

[0026] Figure 4 This is a schematic diagram of a first state of a pouring cone according to an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the second state of the pouring cone according to an embodiment of the present invention;

[0028] The markings in the attached figure are as follows: 1. column; 2. crown beam; 3. steel pipe seat; 4. spliced ​​steel pipe; 41. retaining ring; 42. hydraulic cylinder; 43. retaining structure; 5. casting pipe cone; 51. casting hole; 52. stopper; 53. countersunk hole; 54. through hole; 55. fixing rod; 56. locking nut; 6. digging hole; 7. push block; 71. supporting foot; 81. support column; 82. stopper plate; 83. threaded stopper column; 91. hose; 92. cement pump. DETAILED DESCRIPTION

[0029] like Figure 1~Figure 5 As shown, the present invention discloses a foundation pit retaining structure, such as Figure 1 , Figure 3 and Figure 4 As shown, it includes a plurality of columns 1 arranged on the side surface of the foundation pit and a crown beam 2 supported and connected by the plurality of columns 1, the outer side of the crown beam 2 is fixedly connected to a steel pipe seat 3, the steel pipe seat 3 is sequentially connected to a plurality of spliced ​​steel pipes 4, the spliced ​​steel pipe 4 extends obliquely downward, a casting pipe cone 5 is slidably arranged inside the spliced ​​steel pipe 4, the outer side of the casting pipe cone 5 is slidably matched with the inner side of the spliced ​​steel pipe 4, the upper end of the casting pipe cone 5 is closed, and the lower end is a pointed structure with a hollow interior, and a plurality of casting holes 51 are provided at the lower end of the casting pipe cone 5; it also includes a dug hole 6 opened on the supported ground, the casting pipe cone 5 moves along the spliced ​​steel pipe 4 into the dug hole 6, refer to Figure 2 The upper end of the casting pipe cone 5 is provided with a plurality of insertion holes arranged around the casting pipe cone 5, and the insertion holes are provided with stoppers 52, and the stoppers 52 are fixedly connected to the end of the steel pipe by stud nuts, so that the casting pipe cone 5 is fixed to the end of the spliced ​​steel pipe 4.

[0030] In this scheme, by setting the crown beam 2 and the column 1 structure, a support bracket is provided for the side surface of the foundation pit, and then by setting the oblique support steel pipe structure, the stability of the foundation pit retaining structure is further improved. In this structure, by setting a number of spliced ​​steel pipes 4, this steel pipe structure is more convenient and quick in the subsequent demolition and recycling process. The casting pipe cone 5 is slidably set in the spliced ​​steel pipe 4, and the casting pipe cone 5 slides into the excavated hole 6 through the spliced ​​steel pipe 4. The excavated hole 6 is used for pouring concrete, which is solidified into one with the casting pipe cone 5, so that the oblique steel pipe structure effectively supports the crown beam 2 The pouring pipe cone 5 structure is convenient for pre-digging the hole 6 by setting a structural setting for sliding into the hole 6 internally, and after splicing the steel pipes 4 in sequence, the pouring pipe cone 5 is extended into the hole 6. After pouring the concrete, the enclosure structure forms an effective supporting structure. Compared with pouring first and then splicing, this structure can effectively avoid the problem of changing the oblique support angle or different oblique support lengths caused by the steel pipe splicing error caused by the fixed pouring position after pouring, saving the time waiting for the concrete to solidify. This structure improves the steel pipe support effect and is fast in construction.

[0031] In a further solution, Figure 3 and Figure 4 As shown, two retaining rings 41 are fixedly provided in the middle section of the spliced ​​steel pipe 4 at the end, and a plurality of hydraulic cylinders 42 are provided between the retaining rings 41. The output ends of the hydraulic cylinders 42 extend obliquely toward the ground, and also include a plurality of push blocks 7. The push blocks 7 are inserted into one of the casting holes 51 away from the casting pipe cone 5. The output ends of the hydraulic cylinders 42 are against the push blocks 7, and the hydraulic cylinders 42 push the push blocks 7 to insert the casting pipe cone 5 into the soil at the bottom of the excavated hole 6.

[0032] In this structure, a retaining ring 41 is provided for installing the hydraulic cylinder 42 to provide force support for the hydraulic cylinder 42. The push block 7 is pushed to move by the hydraulic cylinder 42. Several push blocks 7 surround the casting pipe cone 5 and steadily push the casting pipe cone 5 to move, so that the casting pipe cone 5 is inserted into the bottom surface of the hole 6. This structure effectively provides a force structure, and the operation is simple and labor-saving.

[0033] In a further solution, Figure 4 and Figure 5As shown, a supporting foot 71 is extended from the outer end of the push block 7, and the supporting foot 71 extends into the side wall of the excavated hole 6. The width of the push block 7 along the extension direction of the casting tube cone 5 is smaller than the casting hole 51. A countersunk hole 53 is provided in the closed end of the casting tube cone 5 along the extension direction of the casting tube cone 5. A support column 81 is slidably provided in the countersunk hole 53. A baffle 82 is provided at the end of the support column 81, and the baffle 82 is blocked on the upper side of the push block 7 extending into the casting tube cone 5. The ground section of the casting tube cone 5 is also threadedly connected with a threaded baffle column 83, and the threaded baffle column 83 is blocked at the end of the support column 81. When the threaded baffle column 83 is removed, the support column 81 slides along the countersunk hole 53 to the bottom of the countersunk hole 53, and the push block 7 rotates around the casting hole 51 under the support of the hydraulic cylinder 42, so that the supporting foot 71 is in an oblique state on the side wall of the excavated hole 6.

[0034] This structure provides a temporary side support structure for the pyramid cone after the hole 6 is inserted and before the concrete is poured and solidified by setting a plurality of supporting legs 71. The structure also provides a more stable support structure for the push block 7 by setting a baffle plate 82. After the threaded baffle column 83 is removed from the baffle plate 82, the push block 7 loses the end support of the baffle plate 82. Under the continued force of the hydraulic cylinder 42, the push block 7 rotates, causing the supporting legs 71 to be in an oblique state. The plurality of supporting legs 71 form a claw-like structure inclined toward the bottom surface of the hole 6, thereby providing more effective support and anchoring capabilities for the poured cone 5.

[0035] In a further solution, Figure 4 As shown, the closed end of the casting pipe cone 5 also penetrates through a through hole 54, and the through hole 54 is connected to a hose 91. The hose 91 extends from the upper end of the casting pipe cone 5 along the spliced ​​steel pipe 4 to the top of the crown beam 2. A cement pump 92 is provided at the top of the crown beam 2. The cement pump 92 transports concrete into the casting pipe cone 5 through the hose 91.

[0036] In this structure, the closed end of the casting pipe cone 5 should be lower than the ground after the casting pipe cone 5 is in place. After the cement pump 92 outputs concrete, it is input into the casting pipe cone 5 through the hose 91, and flows out of the excavated hole 6 through the casting hole 51, and finally fills the entire excavated hole 6. This structure can effectively ensure that the inside of the casting pipe cone 5 is filled with concrete, thereby improving the overall anchoring ability and supporting ability of the casting pipe cone 5.

[0037] In a further solution, Figure 2 , Figure 4As shown, it also includes a fixing rod 55, and the end of the spliced ​​steel pipe 4 is also provided with a blocking structure 43. The fixing rod 55 passes through the blocking structure 43 and abuts against the push block 7. The output end of the hydraulic cylinder 42 is in contact with the upper end of the fixing rod 55. The upper end of the fixing rod 55 is also threadedly connected with a locking nut 56. After the insertion of the casting pipe cone 5 is completed, the locking nut 56 moves along the fixing rod 55 and abuts against the blocking structure 43.

[0038] By providing the blocking structure 43 , after the hydraulic cylinder 42 is removed, the fixing rod 55 can still provide a support point for the push rod, so that the support rod remains in an inclined state, thereby ensuring the support capacity of the support foot 71 for the casting cone 5 .

[0039] The present invention also discloses a construction method for foundation pit protection, the steps of which are as follows:

[0040] S1. When constructing a foundation pit, cast construction columns 1 and crown beams 2 on the side surface of the foundation pit, and make oblique holes on the crown beams 2;

[0041] S2, pre-opening a hole 6 for pouring concrete at the ground support position of the foundation pit, and the position of the hole 6 is preliminarily determined according to the length of the oblique support steel pipe and the height of the crown beam 2;

[0042] S3, sequentially install a steel pipe seat 3 and a plurality of spliced ​​steel pipes 4 at the oblique opening position of the side wall of the crown beam 2, and place the casting pipe cone 5 into the spliced ​​steel pipe 4 along the oblique opening on the top side of the crown beam 2;

[0043] S4, after the casting steel pipe falls into the dug hole 6 along the spliced ​​steel pipe 4, a hydraulic cylinder 42 is installed between the two retaining rings 41 at the end of the spliced ​​steel pipe 4, a fixing rod 55 is installed at the retaining structure 43, and a supporting foot 71 is inserted into the casting hole 51 of the casting steel pipe;

[0044] S5, the hydraulic cylinder 42 works to push the casting steel pipe into the bottom surface of the dug hole 6 until the insertion hole of the casting steel pipe leaks out, inserts the stopper 52 into the insertion hole, and fixes the stopper 52 at the end of the spliced ​​steel pipe 4;

[0045] S6, remove the threaded stopper 83, the hydraulic cylinder 42 continues to work, so that the support foot 71 is obliquely inserted into the side wall of the hole 6, and then the locking nut 56 is fixed, and the hydraulic cylinder 42 is removed;

[0046] S7. Install a cement pump 92 on the top of the crown beam 2, and fill concrete into the casting steel pipe through the hose 91 of the cement pump 92 until the concrete fills the excavated hole 6.

[0047] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A foundation pit retaining structure, characterized in that: The invention comprises a plurality of columns (1) arranged on the side surface of a foundation pit and a crown beam (2) supported and connected by the plurality of columns (1); the outer side of the crown beam (2) is fixedly connected to a steel pipe seat (3); the steel pipe seat (3) is sequentially connected to a plurality of spliced ​​steel pipes (4); the spliced ​​steel pipes (4) extend obliquely downward; a casting pipe cone (5) is slidably arranged inside the spliced ​​steel pipe (4); the upper end of the casting pipe cone (5) is closed, and the lower end is a pointed structure with a hollow interior; the lower end of the casting pipe cone (5) is provided with a plurality of casting holes (51); and further comprises a hole (6) opened on the supported ground, the casting pipe cone (5) Move along the spliced ​​steel pipe (4) into the dug hole (6), the upper end of the casting pipe cone (5) is provided with a plurality of insertion holes arranged around the casting pipe cone (5), the insertion holes are provided with stoppers (52), the stoppers (52) are fixedly connected to the end of the steel pipe, so that the casting pipe cone (5) is fixed to the end of the spliced ​​steel pipe (4); two stopper rings (41) are fixedly provided in the middle section of the spliced ​​steel pipe (4) at the end, a plurality of hydraulic cylinders (42) are provided between the stopper rings (41), the output ends of the hydraulic cylinders (42) extend obliquely toward the ground, and also include a plurality of push blocks (7), the push blocks (7) are inserted away from the spliced ​​steel pipe (4) In one of the casting holes (51) of the casting tube cone (5), the hydraulic cylinder (42) pushes the push block (7) so that the casting tube cone (5) is inserted into the soil at the bottom of the excavated hole (6); a support foot (71) is extended from the outer end of the push block (7), and the support foot (71) extends into the side wall of the excavated hole (6); the width of the push block (7) along the extension direction of the casting tube cone (5) is smaller than the casting hole (51); a countersunk hole (53) is provided in the closed end of the casting tube cone (5) along the extension direction of the casting tube cone (5); a support column (81) is slidably provided in the countersunk hole (53), and the support column (81) ) is provided with a baffle (82) at the end thereof, the baffle (82) being placed on the upper side of the push block (7) extending into the interior of the casting tube cone (5), and the ground section of the casting tube cone (5) is also threadedly connected with a threaded baffle column (83), the threaded baffle column (83) being placed on the end of the support column (81), and when the threaded baffle column (83) is removed, the support column (81) slides along the countersunk hole (53) to the bottom end of the countersunk hole (53), and the push block (7) rotates around the casting hole (51) under the support of the hydraulic cylinder (42), so that the support foot (71) is in an inclined state on the side wall of the excavated hole (6).

2. The foundation pit retaining structure according to claim 1, characterized in that: The closed end of the casting pipe cone (5) is also penetrated by a through hole (54), and the through hole (54) is connected to a rubber hose (91). The rubber hose (91) extends from the upper end of the casting pipe cone (5) along the spliced ​​steel pipe (4) to the top of the crown beam (2). A cement pump (92) is provided at the top of the crown beam (2). The cement pump (92) transports concrete into the casting pipe cone (5) through the rubber hose (91).

3. The foundation pit retaining structure according to claim 2, characterized in that: It also includes a fixing rod (55), and the end of the spliced ​​steel pipe (4) is also provided with a blocking structure (43), the fixing rod (55) passes through the blocking structure (43) and abuts against the push block (7), the output end of the hydraulic cylinder (42) is in contact with and connected to the upper end of the fixing rod (55), and the upper end of the fixing rod (55) is also threadedly connected with a locking nut (56), and after the insertion of the casting pipe cone (5) is completed, the locking nut (56) moves along the fixing rod (55) and abuts against the blocking structure (43).

4. A construction method for foundation pit retaining, using a foundation pit retaining structure according to claim 3, the steps of which are as follows: S1. When constructing a foundation pit, cast construction columns (1) and crown beams (2) on the side surface of the foundation pit, and make oblique holes on the crown beams (2); S2. Preliminarily opening a hole (6) for pouring concrete at the support position on the foundation pit ground. The position of the hole (6) is preliminarily determined based on the length of the oblique support steel pipe and the height of the crown beam (2); S3, sequentially installing a steel pipe seat (3) and a plurality of spliced ​​steel pipes (4) at the oblique opening position of the side wall of the crown beam (2), and placing a casting pipe cone (5) into the spliced ​​steel pipe (4) along the oblique opening on the top side of the crown beam (2); S4, after the pouring pipe cone (5) falls into the dug hole (6) along the spliced ​​steel pipe (4), a hydraulic cylinder (42) is installed between two retaining rings (41) at the end of the spliced ​​steel pipe (4), a fixing rod (55) is installed at the retaining structure (43), and a supporting foot (71) is inserted into the pouring hole (51) of the pouring pipe cone (5); S5, the hydraulic cylinder (42) works to push the pouring pipe cone (5) into the bottom surface of the dug hole (6) until the insertion hole of the pouring pipe cone (5) leaks out, inserts a stopper (52) into the insertion hole, and fixes the stopper (52) to the end of the spliced ​​steel pipe (4); S6, remove the threaded stopper (83), the hydraulic cylinder (42) continues to work, so that the support foot (71) is obliquely inserted into the side wall of the hole (6), and then the locking nut (56) is fixed and the hydraulic cylinder (42) is removed; S7. Install a cement pump (92) on the top of the crown beam (2), and fill concrete into the pouring pipe cone (5) through the rubber hose (91) of the cement pump (92) until the concrete fills the excavated hole (6).

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