Deep foundation pit construction device and construction method

Abstract

The present invention discloses a deep foundation pit construction device and method. The construction device includes four positioning piles, four retaining plates, a mounting rod, multiple first support mechanisms, and multiple second support mechanisms. The deep foundation pit construction device provided by the present invention can provide support during excavation, preventing soil blocks from falling from the soil layer on the side walls of the deep foundation pit during excavation and affecting normal construction. Furthermore, the deep foundation pit can be supported and reinforced during the curing period after excavation to prevent collapse. The device of the present invention has a simple structure, is easy to construct, greatly shortens the construction period, and improves construction efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of building foundation pit construction, and more particularly to a deep foundation pit construction device and a construction method. Background Art

[0002] A foundation pit excavation depth of 5 meters or more is called a deep foundation pit. During the construction of a deep foundation pit, it is usually necessary to support and block the soil layers on the side walls of the foundation pit to prevent soil blocks on the side walls from falling and affecting construction operations. After the foundation pit excavation is completed, the deep foundation pit needs to be supported and reinforced to prevent the side wall soil layers from moving toward the center during the maintenance of the deep foundation pit, causing the foundation pit structure to collapse.

[0003] The existing support structures of deep foundation pit projects usually include soil nail walls, anchor rods, retaining walls, pile support, underground continuous walls, etc. The selection and design of these support structures need to be analyzed and demonstrated according to specific circumstances. In addition, the construction of the above-mentioned support structures is complicated, the construction is difficult, and the construction efficiency is low. For example, the utility model patent with application number 202121165501.7 discloses a deep foundation pit support device, which is provided by setting two protective walls on the inner wall of the deep foundation pit. The first protective wall is firmly connected to the inner wall of the deep foundation pit by multiple first anchor rods and multiple second anchor rods. A second protective wall formed by a protective net, a first connecting bar, a second connecting bar and a sprayed concrete layer is further provided. A triangular reinforcement plate and support rods are provided between the two adjacent second protective walls to improve the support firmness. The above-mentioned patented technology has many parts and components, and the construction is cumbersome. The construction period required is long, which greatly reduces the construction efficiency. In addition, the support structure of the above-mentioned patented technology is difficult to disassemble. Summary of the Invention

[0004] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0005] In order to achieve these purposes and other advantages according to the present invention, a deep foundation pit construction device is provided, comprising:

[0006] Four positioning piles are respectively located at the four corners of the foundation pit, and each positioning pile is inserted vertically downward into the soil layer. The positioning piles include a positioning cylinder with a hollow structure and a positioning rod coaxially rotatably sleeved in the positioning cylinder. The bottom of each positioning cylinder is provided with a first drill bit with a tip facing downward and a conical structure. The side of the positioning cylinder facing the center of the foundation pit is provided with an arc-shaped notch with a top passing through it in the vertical direction. The arc formed by the vertical projection of the notch is greater than 90°; the top of each positioning rod protrudes from the corresponding positioning cylinder, and the bottom is connected to the corresponding first drill bit in a circumferential direction through a bearing. The positioning rod is provided with two slots with an included angle of 90°, and the two slots intersect and are connected at the center of the positioning rod. Each slot penetrates the top surface of the positioning rod axially and penetrates the circumferential side surface of the positioning rod radially; the inner wall of the slot is provided with a stop bar extending in the vertical direction;

[0007] Four guard plates, one guard plate is set for each side wall of the foundation pit, and the two sides of each guard plate are inserted into the corresponding two slots; a limit groove corresponding to the stop bar is set on the side of each guard plate;

[0008] An installation rod is vertically located in the middle of the foundation pit, and the bottom of the installation rod is inserted into the soil layer below the bottom surface of the foundation pit;

[0009] A plurality of first support mechanisms are arranged at intervals in the vertical direction, each first support mechanism includes four first support rods, each positioning pile is provided with a first support rod, one end of each first support rod is connected to the mounting rod, and the other end extends horizontally along the diagonal line of the foundation pit and is provided with an arc-shaped first support plate, each first support plate is adapted to and abuts against the circumferential side surface of the corresponding positioning rod, and the first support plate is located between the two slots of the corresponding positioning rod;

[0010] Multiple second support mechanisms are arranged at intervals in the vertical direction, each second support mechanism includes four second support rods, and each guard plate is provided with a second support rod. One end of each second support rod is connected to the mounting rod, and the other end extends horizontally in a direction perpendicular to the corresponding guard plate and is provided with a second support plate, and each second support plate abuts against the corresponding guard plate.

[0011] Preferably, in the deep foundation pit construction device, a plurality of first water-permeable holes are provided on the lower circumferential side surface of the mounting rod;

[0012] The construction device also includes a pumping mechanism, which includes a pumping cylinder coaxially sleeved inside the mounting rod and a pumping auger rotatably arranged inside the pumping cylinder; the bottom of the pumping cylinder is provided with a second drill bit with a conical structure inserted into the soil layer below the bottom of the foundation pit, a second water-permeable hole is provided on the lower circumferential side surface of the pumping cylinder, and a drainage outlet connected to the drainage pipe is provided on the top.

[0013] Preferably, in the deep foundation pit construction device, one end of each first support rod is located inside the mounting rod and is provided with a first push plate with an arc-shaped structure, each first push plate is connected to the inner wall of the mounting rod via a horizontally arranged first spring, and the first spring is sleeved on the outside of the corresponding first support rod;

[0014] One end of each second support rod is located inside the mounting rod and is provided with a second push plate with an arc-shaped structure. Each second push plate is connected to the inner wall of the mounting rod via a horizontally arranged second spring, and the second spring is sleeved on the outside of the corresponding second support rod; the four second push plates corresponding to each second support mechanism are arranged to form a hollow conical structure adapted to the tip of the second drill bit;

[0015] The first spring and the second spring are configured as follows: before the water pumping mechanism is inserted into the mounting rod, the four first push plates corresponding to each first support mechanism are arranged into a first conical structure that is adapted to the tip of the second drill bit, and the four second push plates corresponding to each second support mechanism are arranged into a second conical structure that is adapted to the tip of the second drill bit. During the process of inserting the water pumping mechanism into the mounting rod, the second drill bit passes through the first conical structure and the second conical structure, pushing the four first push plates of each first support mechanism and the four second push plates of each second support mechanism radially outward, driving the corresponding first support rod and the second support rod to move horizontally radially outward, and at this time the first spring and the second spring are compressed radially.

[0016] Preferably, in the deep foundation pit construction device, the side of each guard plate is a wedge-shaped structure.

[0017] Preferably, in the deep foundation pit construction device, a detachable cap is provided on the top of the positioning tube of each positioning pile, and the bottom of the cap is detachably connected to the top of the positioning rod.

[0018] Preferably, in the deep foundation pit construction device, each first support plate is provided with a first rubber pad in contact with the circumferential side of the corresponding positioning rod, and each second support plate is provided with a second rubber pad in contact with the corresponding guard plate.

[0019] Preferably, in the deep foundation pit construction device, the outer side surface of each guard plate is provided with an inflatable airbag in contact with the inner wall of the foundation pit.

[0020] The present invention provides a construction method of the deep foundation pit construction device, which comprises:

[0021] S1. Rotate the positioning rod of each positioning pile to a position where the two slots do not interfere with the notches on the corresponding positioning cylinders. Before excavating the deep foundation pit, level and compact the construction site. Draw the top outline of the deep foundation pit on the ground according to the design drawings. Drive positioning piles vertically downward at the four corners of the pre-excavated foundation pit.

[0022] S2. Excavate the first layer of earthwork. After completion, rotate each positioning rod relative to the positioning cylinder until the two slots are parallel to the two adjacent side walls of the foundation pit, and the two slots are radially located in the notch. Vertically set a guard plate on each side wall of the foundation pit, with the two sides of each guard plate corresponding to the slots on both sides in the vertical direction. Insert the guard plate downward in the vertical direction so that the two sides of the guard plate are respectively inserted into the corresponding slots, the outer side of the guard plate contacts the inner wall of the foundation pit, and the bottom of the guard plate contacts the bottom surface of the foundation pit;

[0023] S3, repeating the operation S2 to excavate the 2nd to Nth layers of earthwork. After each layer of earthwork excavation is completed, the retaining plate is moved downward to the bottom of the foundation pit;

[0024] S4. Adjust the length of each first support rod to the difference between the distance between the first support plate and the mounting rod and 1 / 2 the diagonal length of the foundation pit, which is greater than the radius of the pumping cylinder by 1 cm; adjust the length of each second support rod to the difference between the distance between the second support plate and the mounting rod and 1 / 2 the side length of the foundation pit, which is greater than the radius of the pumping cylinder by 1 cm;

[0025] S5. After the excavation of the foundation pit is completed, the installation rod is hoisted to the middle of the foundation pit and the bottom of the installation rod is inserted into the soil layer below the bottom surface of the foundation pit. The pumping mechanism is then vertically inserted into the installation rod, and the second drill bit is inserted into the soil layer below the bottom surface of the foundation pit. The insertion of the pumping mechanism pushes the multiple first push plates and the multiple second push plates radially outward, driving the first support plate and the second support plate to move radially outward. After the pumping mechanism is installed in place, the first support plate abuts against the circumferential side surface of the corresponding positioning rod, and the second support plate abuts against the inner side surface of the corresponding guard plate;

[0026] S6. Inflate the airbags on the outer side of each guard plate; rotate the pumping auger to transport the water at the bottom of the foundation pit upward and drain it into the drain pipe through the drain port;

[0027] S7. After the maintenance of the deep foundation pit is completed, when dismantling the installation rod, the first supporting mechanism and the second supporting mechanism, the pumping cylinder is lifted vertically upwards. Under the elastic restoring force of the first spring, the first push plate and the first supporting rod are driven to move radially inward along the installation rod, and then the first supporting plate is driven to move radially inward, releasing the contact between the first supporting plate and the corresponding positioning rod. Similarly, under the elastic restoring force of the second spring, the second push plate and the second supporting rod are driven to move radially inward along the installation rod, and then the second supporting plate is driven to move radially inward, releasing the contact between the second supporting plate and the corresponding guard plate. The installation rod is lifted vertically upwards to complete the dismantling of the installation rod, the first supporting mechanism and the second supporting mechanism.

[0028] The present invention has at least the following beneficial effects:

[0029] 1. The deep foundation pit construction device provided by the present invention can support the excavation process while digging, thereby preventing soil blocks in the soil layer on the side wall of the deep foundation pit from falling during the excavation process, which affects normal construction. Furthermore, the deep foundation pit can be supported and reinforced during the maintenance period after the excavation is completed to prevent the collapse of the deep foundation pit. The device of the present invention has a simple structure, is easy to construct, greatly shortens the construction period, and improves construction efficiency.

[0030] 2. The present invention is provided with a pumping mechanism inside the mounting rod, which includes a pumping cylinder coaxially inserted into the mounting rod and a pumping auger provided inside the pumping cylinder. By rotating the auger, water is transported upward and discharged to the drain pipe through the drain port on the pumping cylinder, so as to discharge the water collected inside the foundation pit. At the same time, the bottom of the pumping mechanism is inserted deeper into the soil layer below the bottom surface of the deep foundation pit, which can provide support for the mounting rod. Preferably, a clamping component can be provided between the outer wall of the pumping cylinder and the inner wall of the mounting rod, such as a clamping block provided on the outer wall of the pumping cylinder near the upper side, and a groove for accommodating the clamping block is correspondingly provided on the inner wall of the mounting rod, so that the mounting rod and the pumping cylinder support each other.

[0031] 3. The present invention sets a pumping mechanism inside the installation rod, which can be used to pump out the accumulated water inside the foundation pit. At the same time, under the action of the pumping mechanism, the stability of the abutment support between the first support plate and the corresponding positioning rod, and the stability of the abutment support between the second support plate and the corresponding guard plate are improved; further, the installation and removal of the support mechanism are simplified. When removal is required, by lifting the pump cylinder upwards, the multiple first support rods and the second support rods can be automatically reset under the elastic recovery action of the first spring and the second spring, the first support plate and the corresponding positioning rod are released from abutment, and the second support plate and the corresponding guard plate are released from abutment, and the installation rod can be lifted upwards to complete the removal of the support and reinforcement equipment.

[0032] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of a deep foundation pit construction device according to one technical solution of the present invention;

[0034] Figure 2 for Figure 1 A partial enlarged view of middle A;

[0035] Figure 3 It is a structural schematic diagram of the longitudinal section of the installation rod, the first supporting mechanism, and the second supporting mechanism along the center line of the foundation pit in another technical solution of the present invention;

[0036] Figure 4 for Figure 3A partial enlarged view of middle B;

[0037] Figure 5 A schematic structural diagram of the mounting rod, the first supporting mechanism, and the second supporting mechanism in another embodiment of the present invention, taken along a longitudinal section of a foundation pit diagonal line;

[0038] Figure 6 for Figure 5 A partial enlarged view of center C;

[0039] Figure 7 This is a schematic structural diagram of a positioning pile before the positioning rod rotates relative to the positioning cylinder in another technical solution of the present invention;

[0040] Figure 8 It is a structural schematic diagram of the positioning pile in another technical solution of the present invention after the positioning rod rotates relative to the positioning cylinder.

[0041] Explanation of the accompanying drawings: 1-foundation pit; 21-positioning cylinder; 211-notch; 22-positioning rod; 221-slot; 222-stop bar; 23-first drill bit; 24-cap; 3-guard plate; 31-limiting groove; 41-mounting rod; 42-water pumping cylinder; 421-drain pipe; 43-second drill bit; 44-water pumping auger; 51-first support rod; 511-first push plate; 512-first spring; 52-first support plate; 53-first rubber pad; 61-second support rod; 611-cross bar; 612-main support rod; 613-second push plate; 614-second spring; 62-second support plate; 63-second rubber pad. DETAILED DESCRIPTION

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0043] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0044] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0045] In the description of the present invention, the terms "horizontal", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0046] like Figures 1 to 8 As shown, the present invention provides a deep foundation pit construction device 1, which includes:

[0047] Four positioning piles are respectively located at the four corners of the foundation pit 1. Each positioning pile is vertically inserted into the soil layer. The positioning pile includes a positioning cylinder 21 with a hollow structure and a positioning rod 22 coaxially rotating in the positioning cylinder 21. The bottom of each positioning cylinder 21 is provided with a first drill bit 23 with a downward pointed end. The side of the positioning cylinder 21 facing the center of the foundation pit 1 is provided with an arc-shaped notch 211 with a top penetrating along the vertical direction. The arc formed by the vertical projection of the notch 211 is greater than 90 The top of each positioning rod 22 protrudes from the corresponding positioning cylinder 21, and the bottom is connected to the corresponding first drill bit 23 for circumferential rotation via a bearing. The positioning rod 22 is provided with two slots 221 formed at a 90° angle. The two slots 221 intersect and communicate at the center of the positioning rod 22. Each slot 221 axially penetrates the top surface of the positioning rod 22 (the bottom surface is not penetrated) and radially penetrates the circumferential side surface of the positioning rod 22. The inner wall of the slot 221 is provided with a stop bar 222 extending in the vertical direction.

[0048] Four guard plates 3, each side wall of the foundation pit 1 is provided with a guard plate 3, and both sides of each guard plate 3 are inserted into the corresponding two card slots 221; a limit groove 31 corresponding to the stop bar is provided on the side of each guard plate 3; Figure 2 As shown, on the two opposite side walls of the card slot, there are provided stop bars protruding toward the center of the card slot, the stop bars extending in the vertical direction, and correspondingly, on the side of the guard plate, there are provided limit grooves for accommodating the stop bars, so that when the side of the guard plate is inserted into the card slot, the stop bars are accommodated in the limit grooves, limiting the connection between the guard plate and the card slot, thereby improving the support stability;

[0049] An installation rod 41 is vertically located in the middle of the foundation pit 1, and the bottom of the installation rod 41 is inserted into the soil layer below the bottom surface of the foundation pit 1;

[0050] Multiple first support mechanisms are arranged at intervals in the vertical direction, each first support mechanism includes four first support rods 51, and each positioning pile is correspondingly provided with a first support rod 51. One end of each first support rod 51 is connected to the mounting rod 41, and the other end extends horizontally along the diagonal of the foundation pit 1 and is provided with an arc-shaped first support plate 52. Each first support plate 52 is adapted to and abuts against the circumferential side surface of the corresponding positioning rod 22, and the first support plate 52 is located between the two slots 221 of the corresponding positioning rod 22;

[0051] Multiple second support mechanisms are arranged at intervals along the vertical direction, and each second support mechanism includes four second support rods 61. A second support rod 61 is correspondingly provided for each guard plate 3. One end of each second support rod 61 is connected to the mounting rod 41, and the other end extends horizontally in a direction perpendicular to the corresponding guard plate 3 and is provided with a second support plate 62. Each second support plate 62 abuts against the corresponding guard plate 3.

[0052] In the above scheme, the present invention provides a deep foundation pit 1 construction device, which is used to support the side wall of the foundation pit 1 during the construction of the foundation pit 1, and to support and reinforce the side wall of the foundation pit 1 after the construction of the foundation pit 1 is completed. The deep foundation pit 1 construction device includes four positioning piles respectively arranged at the four corners of the deep foundation pit 1, each positioning pile includes a positioning cylinder 21 and a positioning rod 22 that can rotate relatively around the circumference, the positioning cylinder 21 is a hollow structure, the positioning rod 22 is solid, and the bottom of the positioning cylinder 21 is provided with a first drill bit 23 inserted into the soil layer below the bottom surface of the foundation pit 1 (the bottom surface after the construction of the foundation pit 1 is completed), the first drill bit 23 is set to a conical structure with a tip facing downward, a strip-shaped notch 211 is axially provided on the circumferential side surface of the positioning cylinder 21, the notch 211 passes through the top of the positioning cylinder 21 along the axial direction, and the arc shape of the notch 211 along the circumferential direction is greater than 1 / 4 circle, and the positioning rod 22 is connected to the first drill bit 23 (or the lower circumferential side wall of the positioning cylinder 21) through a bearing member. The top of the positioning rod 22 protrudes from the top of the positioning cylinder 21, and the positioning rod 22 is provided with two slots 221 at an angle of 90 degrees. Each slot 221 is a vertically arranged rectangular parallelepiped structure, and the two slots 221 are radially inwardly adjacent to each other at both ends. Each slot 221 penetrates the circumferential side surface of the positioning rod 22 radially outward (the positioning pile is pressed into the soil layer by a static press). Before the positioning pile is lowered into place, the positioning rod 22 is rotated until the two slots 221 thereon do not interfere with the notch 211 of the positioning cylinder 21. The notch 211 on the positioning cylinder 21 is located on the side close to the middle of the deep foundation pit 1, and the two slots 221 are located on the side away from the middle of the deep foundation pit 1. The slot 221 is accommodated in the positioning cylinder 21. During the lowering process of the positioning pile, no soil will enter the slot 221, maintaining the penetration of the slot 221. The side wall of the slot 221 is provided with at least one stop bar 222 extending in the vertical direction;A guard plate 3 is vertically arranged corresponding to each side wall of the foundation pit 1. The guard plate 3 is used to block the soil layer of the side wall of the foundation pit 1 to prevent soil blocks in the soil layer from falling to the middle of the foundation pit 1. According to the horizontal length of the side wall of the foundation pit 1, if the length is too long, the guard plate 3 can be set to a plurality of prefabricated plates that are sequentially spliced ​​with each other along the length direction of the side wall to form an integral guard plate 3 (that is, a guard plate 3 is arranged between any two adjacent positioning piles). Each guard plate 3 can be clamped in the corresponding two slots 221 on the positioning rods 22 on both sides in the horizontal direction. After the positioning pile is put into place, the positioning rod 22 is rotated relative to the positioning cylinder 21 to rotate the two slots 221 on the positioning rod 22 to the notch 2 11 is located on the side, and the two slots 221 are parallel to the two side walls of the deep foundation pit 1 in the radial direction, and the two slots 221 correspond to a right angle of the deep foundation pit 1. The guard plate 3 can be inserted into the slots 221 on both sides from top to bottom. A limiting slot 31 corresponding to the stop bar 222 is provided on the side of the guard plate 3. When inserted into the slot 221, the stop bar 222 corresponds to the limiting slot 31 in the vertical direction. The stop bar 222 is just accommodated in the limiting slot 31. The guard plate 3 is inserted into the slot 221, and under the cooperation of the stop bar 222 and the limiting slot 31, the four guard plates 3 and the four positioning piles are firmly connected together and enclosed to form a closed square frame structure.

[0053] Further, a mounting rod 41 and a plurality of first supporting mechanisms and a plurality of second supporting mechanisms for supporting and reinforcing the deep foundation pit 1 are provided. The mounting rod 41 is vertically arranged in the middle of the foundation pit 1, and the mounting rod 41 is inserted downward into the soil layer below the bottom surface of the foundation pit 1. The plurality of first supporting mechanisms and the plurality of second supporting mechanisms are arranged at intervals in the vertical direction, and the plurality of first supporting mechanisms and the plurality of second supporting mechanisms can be staggered in the vertical direction. Each first supporting mechanism includes four first supporting rods 51, and the four first supporting rods 51 are respectively arranged in one-to-one correspondence with the four positioning rods 22. One end of each first supporting rod 51 is connected to the mounting rod 41, and the other end extends horizontally along the radial direction of the mounting rod 41 toward the direction close to the corresponding positioning rod 22. The extension direction of the first supporting rod 51 is also exactly the deep foundation pit 1 In the direction of the diagonal line, the other end of the first support rod 51 is provided with a first support plate 52 of an arc structure, which can abut against the corresponding positioning rod 22, and the abutting part is located between the two card slots 221; the four first support rods 51 provide a stable horizontal supporting force for the four positioning piles; each second support mechanism includes four second support rods 61, which are arranged one by one in correspondence with the four guard plates 3, one end of each second support rod 61 is connected to the mounting rod 41, and the other end extends horizontally in a direction perpendicular to the corresponding guard plate 3, and the other end of the second support rod 61 is provided with a second support plate 62, which abuts against the corresponding guard plate 3 to provide a stable horizontal supporting force for the guard plate 3; preferably, the first support rod 51 and the second support rod 61 are both telescopic rod bodies;

[0054] The deep foundation pit 1 construction device provided by the present invention can support while digging during the excavation process of the foundation pit 1, so as to avoid the soil blocks in the soil layer on the side wall of the deep foundation pit 1 falling during the excavation process, thereby affecting the normal construction. Furthermore, the deep foundation pit 1 can be supported and reinforced during the maintenance period after the excavation is completed to avoid the collapse of the deep foundation pit 1. The device of the present invention has a simple structure, is easy to construct, greatly shortens the construction period, and improves the construction efficiency.

[0055] Preferably, for a guard plate 3 with an excessively large horizontal length, a plurality of second support rods 61 parallel to each other may be provided for one guard plate 3, which are connected by a horizontally arranged cross bar 611, and the cross bar 611 is connected to the mounting rod 41 through a main support rod. A second support plate 62 is provided at the other end of each second support rod 61 to provide stable support for the guard plate 3.

[0056] In another technical solution, the deep foundation pit 1 construction device is provided with a plurality of first water-permeable holes on the lower circumferential side surface of the mounting rod 41;

[0057] The construction device also includes a pumping mechanism, which includes a pumping cylinder 42 coaxially sleeved inside the installation rod 41 and a pumping auger 44 rotatably arranged inside the pumping cylinder 42; the bottom of the pumping cylinder 42 is provided with a second drill bit 43 of a conical structure inserted into the soil layer below the bottom surface of the foundation pit 1 (the insertion depth of the second drill bit 43 is greater than the insertion depth of the installation rod 41), and a second water-permeable hole is provided on the lower circumferential side surface of the pumping cylinder 42, and a drainage outlet connected to the drainage pipe 421 is provided on the top.

[0058] In the above technical solution, the present invention provides a pumping mechanism inside the mounting rod 41, which includes a pumping cylinder 42 coaxially inserted into the mounting rod 41 and a pumping auger 44 provided inside the pumping cylinder 42. By rotating the auger, water is transported upward and discharged to the drain pipe 421 through the drain port on the pumping cylinder 42, so as to discharge the water collected inside the foundation pit 1. At the same time, the bottom of the pumping mechanism is inserted deeper into the soil layer below the bottom surface of the deep foundation pit 1, which can provide support for the mounting rod 41. Preferably, a locking component can be provided between the outer wall of the pumping cylinder 42 and the inner wall of the mounting rod 41, such as providing a block on the outer wall of the pumping cylinder 42 near the top, and a groove for accommodating the block is correspondingly provided on the inner wall of the mounting rod 41, so that the mounting rod 41 and the pumping cylinder 42 support each other.

[0059] In another technical solution, in the deep foundation pit construction device 1, one end of each first support rod 51 is located inside the mounting rod 41 and is provided with a first push plate 511 with an arc-shaped structure. Each first push plate 511 is connected to the inner wall of the mounting rod 41 through a horizontally arranged first spring 512, and the first spring 512 is sleeved on the outside of the corresponding first support rod 51;

[0060] One end of each second support rod 61 is located inside the mounting rod 41 and is provided with a second push plate 613 with an arc-shaped structure. Each second push plate 613 is connected to the inner wall of the mounting rod 41 via a horizontally arranged second spring 614, and the second spring 614 is sleeved on the outside of the corresponding second support rod 61. The four second push plates 613 corresponding to each second support mechanism are arranged to form a hollow conical structure that adapts to the tip of the second drill bit 43.

[0061] The first spring 512 and the second spring 614 are configured as follows: before the water pumping mechanism is inserted into the mounting rod 41, the four first thrust plates 511 corresponding to each first support mechanism are arranged into a first conical structure that is adapted to the tip of the second drill bit 43, and the four second thrust plates 613 corresponding to each second support mechanism are arranged into a second conical structure that is adapted to the tip of the second drill bit 43. During the process of inserting the water pumping mechanism into the mounting rod 41, the second drill bit 43 passes through the first conical structure and the second conical structure, pushing the four first thrust plates 511 of each first support mechanism and the four second thrust plates 613 of each second support mechanism radially outward, thereby driving the corresponding first support rod 51 and the second support rod 61 to move horizontally radially outward. At this time, the first spring 512 and the second spring 614 are compressed radially.

[0062] In the above technical solution, the present invention sets the connection between one end of the first support rod 51 and one end of the second support rod 61 and the side wall of the installation rod 41 as an elastic connection. During the insertion of the pumping mechanism, the thrust of the second drill bit 43 can be used to synchronously push one end of multiple first support rods 51 and one end of multiple second support rods 61 outward in the radial direction, thereby driving the first support rod 51 and the second support rod 61 to move outward in the radial direction, driving the first support plate 52 to move horizontally in the direction close to the positioning rod 22, and driving the second support plate 62 to move in the direction close to the guard plate 3. When the pumping mechanism is inserted into place, the first support rod 51 and the second support rod 61 are pushed outward in the radial direction. The arc-shaped concave surface of the support plate 52 is in sealing contact with the circumferential side surface of the corresponding positioning rod 22, and the second support plate 62 is in sealing contact with the inner side surface of the corresponding guard plate 3 (the side surface close to the foundation pit 1 is the inner side surface). At this time, the first spring 512 and the second spring 614 are both in a compressed state; when disassembly is required, the pumping cylinder 42 is lifted upward, and the first support rod 51 is retracted radially inwardly under the elastic force of the first spring 512, and the first support plate 52 is released from contact with the circumferential side surface of the positioning rod 22. Similarly, the second support plate 62 is retracted radially inwardly under the elastic force of the second spring 614, and the second support plate 62 is released from contact with the guard plate 3.

[0063] Before lowering the mounting rod 41, if the length of the first support rod 51 is directly adjusted to the length at which the first support plate 52 and the positioning rod 22 can abut, and the length of the second support rod 61 is directly adjusted to the length at which the second support plate 62 abuts against the outer side of the guard plate 3, a large friction force will be generated, making it difficult to lower the mounting rod 41. Therefore, in order to ensure the lowering operation of the mounting rod 41, a certain distance should be kept between the first support plate 52 and the corresponding positioning rod 22 to avoid friction caused by contact between the first support plate 52 and the corresponding positioning rod 22. After being put in place, by inserting the pumping mechanism vertically downward into the installation rod 41, the second drill bit 43 passes through the first conical structure formed by the multiple first push plates 511 and the second conical structure formed by the multiple second push plates 613, and pushes the multiple first push plates 511 and the multiple second push plates 613 radially outward, thereby pushing the multiple first support rods 51 and the multiple second support rods 61 radially outward, thereby pushing the first support plate 52 toward the direction close to the positioning rod 22, and pushing the second support plate 62 toward the direction close to the guard plate 3. When the second drill bit 43 When the first conical structure and the second conical structure are completely passed, the first push plate 511 abuts against the outer wall of the water pumping cylinder 42, and the first spring 512 is compressed. The first support rod 51 and the first support plate 52 move radially to the limit position, and the first support plate 52 abuts against the circumferential side of the positioning rod 22 in a sealed manner. The second push plate 613 abuts against the outer wall of the water pumping cylinder 42, and the second spring 614 is compressed. The second support rod 61 and the second support plate 62 move radially to the limit position, and the second support plate 62 abuts against the inner side of the guard plate 3 in a sealed manner. Under the action of , the stability of the support between the first support plate 52 and the corresponding positioning rod 22 is improved, and the stability of the support between the second support plate 62 and the corresponding guard plate 3 is improved; when dismantling is required, by lifting the pump cylinder 42 upward, under the elastic recovery action of the first spring 512 and the second spring 614, multiple first support rods 51 and second support rods 61 can be automatically reset, the first support plate 52 and the corresponding positioning rod 22 are released from the contact, the second support plate 62 and the corresponding guard plate 3 are released from the contact, and the installation rod 41 can be lifted upward to complete the dismantling of the support and reinforcement equipment.

[0064] In another technical solution, in the deep foundation pit 1 construction device, the side of each guard plate 3 is a wedge-shaped structure. The side of the guard plate 3 is set as a wedge-shaped structure so that the adjacent sides of two adjacent guard plates 3 are better fitted and contacted at the position where the two slots 221 are connected.

[0065] In another technical solution, in the deep foundation pit construction device 1, a removable cap 24 is provided on the top of the positioning tube 21 of each positioning pile, the bottom of which is removably connected to the top of the positioning rod 22. The removable cap 24 is provided on the top of the positioning tube 21. Before the positioning pile is lowered into place, the cap 24 can be placed on the top of the positioning tube 21 and the top of the cap 24 can be connected to the top of the positioning rod 22, thereby temporarily fixing the positioning tube 21 and the positioning rod 22 to prevent the positioning rod 22 from rotating relative to the positioning tube 21 during the lowering of the positioning pile. The removable connection between the cap 24, the positioning tube 21, and the positioning rod 22 can be achieved by referring to the structural method of the snap fastener in the prior art.

[0066] In another technical solution, in the deep foundation pit 1 construction device, each first support plate 52 is provided with a first rubber pad 53 that contacts the circumferential side surface of the corresponding positioning rod 22, and each second support plate 62 is provided with a second rubber pad 63 that contacts the corresponding guard plate 3. The elastic rubber pads provided on both the first support plate 52 and the second support plate 62 provide a certain degree of extrusion elasticity between the first support plate 52 and the positioning rod 22, and between the second support plate 62 and the guard plate 3, thereby ensuring a more secure abutment and preventing direct, hard contact between the first support plate 52 and the positioning rod 22, and between the second support plate 62 and the guard plate 3, which could cause friction damage.

[0067] In another technical solution, in the deep foundation pit 1 construction device, the outer side of each guard plate 3 is provided with an inflatable airbag in contact with the inner wall of the foundation pit 1. The inflatable airbag can fill the space between the guard plate 3 and the inner wall of the foundation pit 1 to ensure the stability of the guard plate 3 support.

[0068] The present invention also provides a construction method of the deep foundation pit construction device 1, which comprises:

[0069] S1. Rotate the positioning rod 22 of each positioning pile to a position where the two slots 221 do not interfere with the notch 211 on the corresponding positioning cylinder 21. Place the cap 24 on the top of the positioning cylinder 21, and connect the bottom of the cap 24 to the top of the positioning rod 22. This temporarily secures the positioning cylinder 21 to the positioning rod 22, preventing the positioning rod 22 from rotating relative to the positioning cylinder 21 during the lowering of the positioning pile.

[0070] S2. Before excavating the deep foundation pit 1, the construction site is leveled and compacted. According to the design drawings, the top outline of the deep foundation pit 1 is drawn on the ground of the construction site. Positioning piles are driven vertically downward at the four corners of the pre-excavated foundation pit 1 (static pressure pile drivers are used to sink the positioning piles). The square size enclosed by the axes of the four positioning piles is slightly smaller than the square size of the foundation pit 1.

[0071] S2. Excavate the first layer of earthwork. After completion, one side of each positioning pile close to the middle of the deep foundation pit 1 is exposed to the outside; remove the cap 24, and rotate each positioning rod 22 relative to the positioning cylinder 21 until the two slots 221 are parallel to the two adjacent side walls of the foundation pit 1, and the two slots 221 are radially located in the notch 211. A guard plate 3 is vertically arranged on each side wall of the foundation pit 1, and the two sides of each guard plate 3 are respectively vertically corresponding to the slots 221 on both sides. Insert the guard plate 3 downward in the vertical direction so that the two sides of the guard plate 3 are respectively inserted into the corresponding slots 221 (at the same time, the stop bar 222 is just accommodated in the corresponding limit groove 31), and the outer side of the guard plate 3 contacts the inner wall of the foundation pit 1, and the bottom contacts the bottom surface of the foundation pit 1;

[0072] S3, repeating the operation S2 to excavate the 2nd to Nth layers of earthwork until the depth of the deep foundation pit 1 reaches the preset depth. After each layer of earthwork excavation is completed, the retaining plate 3 is moved downward to the bottom surface of the foundation pit 1;

[0073] S4. Adjust the length of each first support rod 51 to the length of the distance between the first support plate 52 and the installation rod 41, and the difference between the length of the diagonal line of the foundation pit 1 and 1 / 2 is greater than the radius of the pumping cylinder 42 by 1 cm; adjust the length of each second support rod 61 to the length of the distance between the second support plate 62 and the installation rod 41, and the difference between the length of the diagonal line of the foundation pit 1 and 1 / 2 is greater than the radius of the pumping cylinder 42 by 1 cm;

[0074] S5. After the excavation of the foundation pit 1 is completed, the installation rod 41 is hoisted to the middle of the foundation pit 1 and the bottom of the installation rod 41 is inserted into the soil layer below the bottom surface of the foundation pit 1. The pumping mechanism is then vertically inserted into the installation rod 41, and the second drill bit 43 is inserted into the soil layer below the bottom surface of the foundation pit 1. The insertion of the pumping mechanism pushes the multiple first push plates 511 and the multiple second push plates 613 radially outward, driving the first support plate 52 and the second support plate 62 to move radially outward. After the pumping mechanism is installed in place, the first support plate 52 abuts against the corresponding circumferential side surface of the positioning rod 22, and the second support plate 62 abuts against the corresponding inner side surface of the guard plate 3;

[0075] S6. Inflate the airbags on the outer side of each guard plate 3 to fill the gap between the guard plate 3 and the inner wall of the foundation pit 1; rotate the pumping auger 44 to transport the water at the bottom of the foundation pit 1 upward and drain it to the drain pipe 421 through the drain port;

[0076] S7. After the maintenance of the deep foundation pit 1 is completed, when the installation rod 41, the first supporting mechanism and the second supporting mechanism are dismantled, the pumping cylinder 42 is lifted vertically upwards. Under the elastic recovery force of the first spring 512, the first push plate 511 and the first support rod 51 are driven to move radially inward along the installation rod 41, and then the first support plate 52 is driven to move radially inward, releasing the contact between the first support plate 52 and the corresponding positioning rod 22. Similarly, under the elastic recovery force of the second spring 614, the second push plate 613 and the second support rod 61 are driven to move radially inward along the installation rod 41, and then the second support plate 62 is driven to move radially inward, releasing the contact between the second support plate 62 and the corresponding guard plate 3. The installation rod 41 is lifted vertically upwards to complete the disassembly of the installation rod 41, the first supporting mechanism and the second supporting mechanism.

[0077] The construction method of the deep foundation pit 1 construction device provided by the present invention can realize excavation and support at the same time, and can further support and reinforce the foundation pit 1 after the construction is completed, thereby improving the stability of the foundation pit 1 during the curing period. At the same time, the construction method provided by the present invention has high construction efficiency and a short construction period.

[0078] The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be readily apparent to those skilled in the art.

[0079] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. Deep foundation pit construction device, characterized in that, include: Four positioning piles are respectively located at the four corners of the foundation pit, and each positioning pile is inserted vertically downward into the soil layer. The positioning piles include a positioning cylinder with a hollow structure and a positioning rod coaxially rotatably sleeved in the positioning cylinder. The bottom of each positioning cylinder is provided with a first drill bit with a tip facing downward and a conical structure. The side of the positioning cylinder facing the center of the foundation pit is provided with an arc-shaped notch with a top passing through it in the vertical direction. The arc formed by the vertical projection of the notch is greater than 90°; the top of each positioning rod protrudes from the corresponding positioning cylinder, and the bottom is connected to the corresponding first drill bit in a circumferential direction through a bearing. The positioning rod is provided with two slots with an included angle of 90°, and the two slots intersect and are connected at the center of the positioning rod. Each slot penetrates the top surface of the positioning rod axially and penetrates the circumferential side surface of the positioning rod radially; the inner wall of the slot is provided with a stop bar extending in the vertical direction; Four guard plates, one guard plate is set for each side wall of the foundation pit, and the two sides of each guard plate are inserted into the corresponding two slots; a limit groove corresponding to the stop bar is set on the side of each guard plate; An installation rod is vertically located in the middle of the foundation pit, and the bottom of the installation rod is inserted into the soil layer below the bottom surface of the foundation pit; A plurality of first support mechanisms are arranged at intervals in the vertical direction, each first support mechanism includes four first support rods, each positioning pile is provided with a first support rod, one end of each first support rod is connected to the mounting rod, and the other end extends horizontally along the diagonal line of the foundation pit and is provided with an arc-shaped first support plate, each first support plate is adapted to and abuts against the circumferential side surface of the corresponding positioning rod, and the first support plate is located between the two slots of the corresponding positioning rod; Multiple second support mechanisms are arranged at intervals in the vertical direction, each second support mechanism includes four second support rods, and each guard plate is provided with a second support rod. One end of each second support rod is connected to the mounting rod, and the other end extends horizontally in a direction perpendicular to the corresponding guard plate and is provided with a second support plate, and each second support plate abuts against the corresponding guard plate.

2. The deep foundation pit construction device according to claim 1, characterized in that: A plurality of first water-permeable holes are provided on the lower circumferential side surface of the mounting rod; The construction device also includes a pumping mechanism, which includes a pumping cylinder coaxially sleeved inside the mounting rod and a pumping auger rotatably arranged inside the pumping cylinder; the bottom of the pumping cylinder is provided with a second drill bit with a conical structure inserted into the soil layer below the bottom of the foundation pit, a second water-permeable hole is provided on the lower circumferential side surface of the pumping cylinder, and a drainage outlet connected to the drainage pipe is provided on the top.

3. The deep foundation pit construction device according to claim 2, characterized in that: One end of each first support rod is located inside the mounting rod and is provided with a first push plate with an arc-shaped structure. Each first push plate is connected to the inner wall of the mounting rod via a horizontally arranged first spring, and the first spring is sleeved on the outside of the corresponding first support rod; One end of each second support rod is located inside the mounting rod and is provided with a second push plate with an arc-shaped structure. Each second push plate is connected to the inner wall of the mounting rod via a horizontally arranged second spring, and the second spring is sleeved on the outside of the corresponding second support rod; the four second push plates corresponding to each second support mechanism are arranged to form a hollow conical structure adapted to the tip of the second drill bit; The first spring and the second spring are configured as follows: before the water pumping mechanism is inserted into the mounting rod, the four first push plates corresponding to each first support mechanism are arranged into a first conical structure that is adapted to the tip of the second drill bit, and the four second push plates corresponding to each second support mechanism are arranged into a second conical structure that is adapted to the tip of the second drill bit. During the process of inserting the water pumping mechanism into the mounting rod, the second drill bit passes through the first conical structure and the second conical structure, pushing the four first push plates of each first support mechanism and the four second push plates of each second support mechanism radially outward, driving the corresponding first support rod and the second support rod to move horizontally radially outward, and at this time the first spring and the second spring are compressed radially.

4. The deep foundation pit construction device according to claim 3, characterized in that: The side of each guard plate is a wedge-shaped structure.

5. The deep foundation pit construction device according to claim 4, characterized in that: A detachable cap is provided on the top of the positioning tube of each positioning pile, and the bottom of the cap is detachably connected to the top of the positioning rod.

6. The deep foundation pit construction device according to claim 5, characterized in that: A first rubber pad in contact with the circumferential side surface of the corresponding positioning rod is provided on each first supporting plate, and a second rubber pad in contact with the corresponding guard plate is provided on each second supporting plate.

7. The deep foundation pit construction device according to claim 6, characterized in that: The outer side surface of each guard plate is provided with an inflatable air bag in contact with the inner wall of the foundation pit.

8. The construction method of the deep foundation pit construction device according to claim 7, characterized in that: include: S1. Rotate the positioning rod of each positioning pile until the two slots do not interfere with the notches on the corresponding positioning cylinder; Before excavating the deep foundation pit, the construction site should be leveled and compacted. According to the design drawings, the top outline of the deep foundation pit should be drawn on the ground of the construction site. Positioning piles should be driven vertically downwards at the four corners of the pre-excavated foundation pit. S2. Excavate the first layer of earthwork. After completion, rotate each positioning rod relative to the positioning cylinder until the two slots are parallel to the two adjacent side walls of the foundation pit, and the two slots are radially located in the notch. Vertically set a guard plate on each side wall of the foundation pit, with the two sides of each guard plate corresponding to the slots on both sides in the vertical direction. Insert the guard plate downward in the vertical direction so that the two sides of the guard plate are respectively inserted into the corresponding slots, the outer side of the guard plate contacts the inner wall of the foundation pit, and the bottom of the guard plate contacts the bottom surface of the foundation pit; S3, repeating the operation S2 to excavate the 2nd to Nth layers of earthwork. After each layer of earthwork excavation is completed, the retaining plate is moved downward to the bottom of the foundation pit; S4. Adjust the length of each first support rod to the difference between the distance between the first support plate and the mounting rod and 1 / 2 the diagonal length of the foundation pit, which is greater than the radius of the pumping cylinder by 1 cm; adjust the length of each second support rod to the difference between the distance between the second support plate and the mounting rod and 1 / 2 the side length of the foundation pit, which is greater than the radius of the pumping cylinder by 1 cm; S5. After the excavation of the foundation pit is completed, the installation rod is hoisted to the middle of the foundation pit and the bottom of the installation rod is inserted into the soil layer below the bottom surface of the foundation pit. The pumping mechanism is then vertically inserted into the installation rod, and the second drill bit is inserted into the soil layer below the bottom surface of the foundation pit. The insertion of the pumping mechanism pushes the multiple first push plates and the multiple second push plates radially outward, driving the first support plate and the second support plate to move radially outward. After the pumping mechanism is installed in place, the first support plate abuts against the circumferential side surface of the corresponding positioning rod, and the second support plate abuts against the inner side surface of the corresponding guard plate; S6. Inflate the airbags on the outer side of each guard plate; rotate the pumping auger to transport the water at the bottom of the foundation pit upward and drain it into the drain pipe through the drain port; S7. After the maintenance of the deep foundation pit is completed, when dismantling the installation rod, the first supporting mechanism and the second supporting mechanism, the pumping cylinder is lifted vertically upwards. Under the elastic restoring force of the first spring, the first push plate and the first supporting rod are driven to move radially inward along the installation rod, and then the first supporting plate is driven to move radially inward, releasing the contact between the first supporting plate and the corresponding positioning rod. Similarly, under the elastic restoring force of the second spring, the second push plate and the second supporting rod are driven to move radially inward along the installation rod, and then the second supporting plate is driven to move radially inward, releasing the contact between the second supporting plate and the corresponding guard plate. The installation rod is lifted vertically upwards to complete the dismantling of the installation rod, the first supporting mechanism and the second supporting mechanism.

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