A method for deep foundation pit excavation construction on both sides of an existing building

Abstract

The application discloses a kind of existing building both sides deep foundation pit excavation construction method, it is related to foundation pit construction technical field, steps include: S1, excavate foundation pit simultaneously in both sides of original building, the driving direction of two foundation pits is perpendicular to original building and left and right opposite;S2, stop driving when excavating to the original slope protection pile of original building periphery exposure, and install this period slope protection structure in the position of original slope protection pile.In original building both sides excavate foundation pit, the driving direction of two foundation pits is left and right opposite and excavation progress keeps consistent, to avoid original building unilateral settlement due to eccentric load, maximum limit to ensure the safety of original building.This period slope protection pile, this period slope protection board are anchored cable connection by depending on original slope protection pile, simplify pull connection structure, further improve construction efficiency.Dowels are connected from bottom to top on the surface of this period waist beam, to avoid this period waist beam from torsion damage, to avoid the problem that first bolt thread is damaged and cannot be unscrewed.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit construction, and in particular to a construction method for excavating deep foundation pits on both sides of an existing building. Background Art

[0002] A deep foundation pit refers to a project with an excavation depth of more than 5 meters (including 5 meters), or a project with a depth of less than 5 meters but with particularly complex geological conditions, surrounding environment and underground pipelines.

[0003] With the continuous advancement of urban development, newly planned buildings in urban spaces often face the problem of land shrinkage, which limits the horizontal planning of buildings. The focus must be on fully utilizing the planned land, increasing the above-ground space, or deepening the basement. Therefore, it is necessary not only to solve the construction difficulties of deep foundation pits themselves, but also to minimize the adverse effects of deep foundation pit excavation on surrounding buildings. In traditional technologies, one-sided construction causes unilateral settlement of the existing building, which is a common adverse effect during the operation. Summary of the Invention

[0004] In order to solve the problem in the above background technology regarding "excavating a deep foundation pit on one side of a building causing one-sided settlement of the original building", the present invention provides a construction method for excavating deep foundation pits on both sides of an existing building.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a construction method for excavating deep foundation pits on both sides of an existing building, the steps comprising: S1, excavating foundation pits on both sides of the original building at the same time, with the excavation directions of the two foundation pits being perpendicular to the original building and opposite to each other on the left and right; S2, stopping excavation when the original slope protection piles around the original building are exposed, and installing a current slope protection structure at the position of the original slope protection piles; the current slope protection structure includes current slope protection piles, current slope protection boards, current crown beams, current waist beams and current support components.

[0006] In step S2, the installation steps of the current slope protection structure include: S21, arranging the current slope protection piles at the edge of the foundation pit close to the original slope protection piles, with the number of the current slope protection piles being equal to and corresponding to the exposed original slope protection piles; S22, installing the current slope protection boards at the side walls of the current slope protection piles close to the original slope protection piles; S23, horizontally installing the current crown beams at the tops of the current slope protection piles;

[0007] S24. Install the current waist beam transversely in the middle of the side wall of the current slope protection pile; S25. Use the first anchor cable to pull the current waist beam to the original waist beam at the waist of the original slope protection pile; S26. Install the current support assembly diagonally on the current waist beam, and the current support assembly is located in the middle of the gap between two adjacent current slope protection piles; S27. Backfill part of the excavated soil into the gap between the original slope protection pile and the current slope protection board.

[0008] As a further optimization solution of the present invention, the current waist beam and the current slope protection board are respectively arranged on both sides of the current slope protection piles.

[0009] As a further optimization solution of the present invention, the slope protection board of this phase is provided with a plug-in hole for the insertion of the first anchor cable.

[0010] In step S21, the installation steps of the slope protection piles of this phase include: S211, rotary excavating pile foundation holes in the foundation pit; S212, inserting the slope protection piles of this phase into the pile foundation holes with the top ends exposed; S213, filling the gaps between the slope protection piles of this phase and the pile foundation holes with fillers.

[0011] As a further optimization scheme of the present invention, the current support assembly includes a rod body and a fastener; the fastener is a U-shaped plate structure, and the inner cavity of the fastener can adapt to and clamp the side wall of the current waist beam; the end of the fastener close to the opening is provided with a detachable first bolt passing through the side wall position, and the end of the fastener side wall away from the opening is hinged to the end of the rod body.

[0012] As a further optimization solution of the present invention, the first bolt is connected to the fastener via threads.

[0013] As a further optimization solution of the present invention, the side wall of the fastener is provided with a first screw hole adapted for the first bolt, and the distance H between the bottom surface of the first screw hole and the bottom surface of the fastener inner cavity is not less than the height of the current waist beam.

[0014] As a further optimization scheme of the present invention, step S26 includes the following steps: S261, fasten the fastener to the bottom wall and side wall of the current waist beam from bottom to top, and then screw the first bolt into the inner cavity of the fastener and tighten it. At this time, the first bolt is located above the current waist beam; S262, insert the end of the rod body away from the fastening into the ground of the foundation pit.

[0015] As a further optimization scheme of the present invention, step S262 includes the following steps: S2621, rotary excavating a receiving pit in the foundation pit; S2622, inserting the end of the rod body away from the fastener into the receiving pit, and then pouring concrete into the receiving pit; S2623, after the concrete in the receiving pit hardens, forming an abutment block for abutting the foundation pit.

[0016] In summary, the present invention is beneficial in that:

[0017] (1) Excavate foundation pits on both sides of the original building at the same time. The excavation directions of the two foundation pits are opposite to each other and the excavation progress is kept consistent, so as to avoid unilateral settlement of the original building due to eccentric loading and ensure the safety of the original building to the greatest extent.

[0018] (2) The current slope protection piles and slope protection boards are connected with anchor cables by attaching them to the original slope protection piles, which improves the construction convenience, simplifies the connection structure, and further improves the construction efficiency.

[0019] (3) The support assembly of this phase includes a rod and a fastener. When the fastener is fastened to the surface of the waist beam of this phase from bottom to top, the rod can apply a support force obliquely upward and directed to the slope guardrail of this phase to the side of the bottom of the fastener away from the slope guardrail of this phase, thereby achieving stable support, avoiding torsional damage to the waist beam of this phase, and avoiding the problem that the first bolt thread is damaged and cannot be unscrewed.

[0020] (4) The current support assembly is arranged in a Y-shape and connects two current waist beams at the same time, thereby avoiding the stress concentration problem caused by connecting a single current waist beam, achieving uniform load-bearing, and improving the support capacity of the current slope protection piles and current slope protection boards. It further compensates for the problem that the original slope protection piles and original waist beams cannot provide sufficient tension to the current slope protection structure due to aging, thereby improving the support safety and avoiding the occurrence of safety accidents such as support failure.

[0021] (5) If the ground of the foundation pit is uneven, the rod bodies at different positions will overlap the ends on the ground of the foundation pit. The hinge positions of the rod bodies and the abutting rods will have different heights. Therefore, the abutting rods will be pressed on the arc-shaped tooth structure at different angles. The arc-shaped tooth structure is an upward convex arc, so it has greater compatibility with the pressing angle of the abutting rod, thereby achieving stable and convenient engagement between the arc-shaped tooth structure and the first straight rack structure, thereby improving construction safety and convenience. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present application is further described below with reference to the accompanying drawings:

[0023] Figure 1 This is a top-down diagram of the foundation pit being excavated simultaneously on both sides of the original building;

[0024] Figure 2This is a front view schematic diagram of the connection structure between the original slope protection piles and the current slope protection piles;

[0025] Figure 3 This is a top view schematic diagram of the connection structure of the slope protection piles, slope protection boards, waist beam connections and support components of this phase;

[0026] Figure 4 This is a front view schematic diagram of the connection structure between the current support assembly and the current waist beam;

[0027] Figure 5 It is a schematic diagram of the cross-sectional structure of the fastener;

[0028] Figure 6 This is a schematic diagram of the state where the fastener is fastened on the waist beam from top to bottom and the rod body is connected to the bottom end of the fastener;

[0029] Figure 7 This is a schematic diagram of the fastener being fastened from top to bottom on the waist beam of this issue and the rod body being connected to the top end of the fastener;

[0030] Figure 8 A schematic diagram of the connection structure between the fastening member and the abutment rod;

[0031] Figure 9 To accommodate the gap position and structural diagram;

[0032] Figure 10 This is a schematic diagram of the structure in which the abutment rod is connected to the fastening member in an inclined shape.

[0033] In the figure,

[0034] 1. Existing buildings;

[0035] 2. Foundation pit; 21. Accommodation pit;

[0036] 3. Original slope protection piles; 31. Original crown beam; 32. Original waist beam;

[0037] 4. Slope protection piles in this period;

[0038] 5. This phase of slope protection board; 51. Give way clearance;

[0039] 6. Crown beam of this issue;

[0040] 7, current waist beam; 701, first waist beam; 702, second waist beam; 71, first anchor cable; 72, second anchor cable;

[0041] 8. Support assembly of this issue; 81. Rod body; 82. Fastener; 821. First screw hole; 822. Corner structure; 83. First bolt; 84. Fastener; 841. Second bolt; 842. Arc-shaped tooth structure; 843. Bundling fins; 8431. Accommodation gap; 85. Abutment rod; 851. Second straight rack structure; 86. Iron wire. DETAILED DESCRIPTION

[0042] Based on the above structural features of the present application, the implementation methods of the present application are further described:

[0043] Reference Figures 1 and 2 This embodiment provides a method for excavating deep foundation pits on both sides of an existing building, comprising the following steps: S1. Excavating foundation pits 2 simultaneously on both sides of an existing building 1. The excavation direction of both foundation pits 2 is perpendicular to the existing building 1. Both foundation pits 2 are excavated from far to near, i.e., the excavation directions of the two foundation pits 2 are opposite to each other. The excavation progress of the two foundation pits 2 is kept consistent, thereby preventing unilateral settlement of the existing building 1 due to eccentric loading.

[0044] S2. Stop excavating when the original slope protection piles 3 around the original building 1 are exposed, and install the current slope protection structure at the position of the original slope protection piles 3.

[0045] Reference Figures 1 and 2 The original slope protection piles 3 are slope protection piles that are inserted into the soil layer during the construction of the foundation of the original building 1, and are then buried underground with the backfill of the moving earth.

[0046] Reference Figures 1 and 2 The slope protection structure includes slope protection piles 4, slope protection boards 5, top beams 6, waist beams 7, and support components 8. These structures work together to support the sidewalls of the foundation pit 2, preventing edge collapse and improving construction safety.

[0047] Reference Figures 1 to 3 In step S2, the installation steps of the slope protection structure in this phase include:

[0048] S21. Arrange the slope protection piles 4 of the current phase at the edge of the foundation pit 2 close to the original slope protection piles 3. The number of the slope protection piles 4 of the current phase is equal to the number of the original slope protection piles 3 in the exposed state and they correspond one to one.

[0049] S22. Install the current slope protection plate 5 on the current slope protection pile 4 near the side wall of the original slope protection pile 3. The current slope protection plate 5 is a steel plate, and the current slope protection pile 4 is a prefabricated reinforced concrete structure. A first sleeve is embedded in the side wall of the current slope protection pile 4 during prefabrication. The first sleeve is fixedly connected to the steel mesh inside the current slope protection pile 4. The user fastens the steel plate to the current slope protection pile 4 with bolts, which are tightened in the first sleeve.

[0050] S23. Install the current crown beam 6 transversely on the top of the current slope protection pile 4. The current crown beam 6 is a steel beam; a second sleeve is embedded in the top of the current slope protection pile 4 during prefabrication. The second sleeve is fixedly connected to the steel mesh inside the current slope protection pile 4. The user fastens the current crown beam 6 to the current slope protection pile 4 with bolts, which are tightened in the second sleeve.

[0051] S24. Install the current waist beam 7 transversely in the middle of the side wall of the current slope protection pile 4. The current waist beam 7 is a steel beam; a third sleeve is embedded in the side wall of the current slope protection pile 4 during prefabrication. The third sleeve is fixedly connected to the steel mesh inside the current slope protection pile 4. The user fastens the current waist beam 7 to the current slope protection pile 4 with bolts, which are tightened in the third sleeve.

[0052] S25. Use the first anchor cable 71 to pull the current side beam 7 together with the original side beam 32 at the waist of the original slope protection pile 3. If the original slope protection pile 3 is unable to exert sufficient tension on the current slope protection pile 4 (for example, due to aging and loosening between the original slope protection pile 3 and the pile foundation hole, or between the original slope protection pile 3 and the original side beam 32), install the second anchor cable 72 after the first anchor cable 71 is installed. The second anchor cable 72 is used to assist the first anchor cable 71 in bearing the load and jointly pull the current slope protection board 5 and the current side beam 7 together.

[0053] S26, the current support assembly 8 is installed diagonally on the current waist beam 7, and the current support assembly 8 is located in the middle position of the gap between two adjacent current slope protection piles 4;

[0054] S27, backfilling part of the excavated earth into the gap between the original slope protection pile 3 and the current slope protection board 5, so that the current slope protection board 5 is pushed by the backfill earth and the first anchor cable 71 is tightened.

[0055] The current waist beam 7 and the current slope protection board 5 are respectively arranged on both sides of the current slope protection pile 4, so that the current slope protection pile 4 can exert a supporting force on the current slope protection board 5 to resist the thrust from the backfill soil.

[0056] In this issue, the slope protection board 5 is provided with several plug-in holes for the insertion of the first anchor cable 71 and the second anchor cable 72. The user can insert either end of the first anchor cable 71 into the plug-in hole and insert either end of the second anchor cable 72 into the plug-in hole, so that the first anchor cable 71 and the second anchor cable 72 remain in a straight line after tensioning, thereby improving the pulling stability.

[0057] In step S21, the installation steps of the slope protection piles 4 of this phase include: S211, rotary excavating a pile foundation hole in the foundation pit 2; S212, inserting the slope protection piles 4 of this phase into the pile foundation hole with the top exposed; S213, filling the gap between the slope protection piles 4 of this phase and the pile foundation hole with a filler (filler such as concrete); after the filler is shaped, the installation of the slope protection piles 4 of this phase is completed.

[0058] In step S25, the installation steps of the second anchor cable 72 include: S251, rotary excavation of a connection hole in the soil layer on the side of the original slope protection pile 3 away from the current slope protection pile 4; S252, inserting one end of the second anchor cable 72 into the connection hole, and then pouring concrete into the connection hole; S253, after the concrete hardens, connecting the other end of the second anchor cable 72 to the current slope protection pile 4, and tightening the second anchor cable 72.

[0059] Reference Figures 3 to 5 The support assembly 8 of this period includes a rod body 81 and a fastener 82; the fastener 82 is a U-shaped plate structure, and the inner cavity of the fastener 82 can adapt to the side wall of the waist beam 7 of this period; a detachable first bolt 83 is provided through the side wall position of the fastener 82 at the end close to the opening, and the end of the side wall of the fastener 82 away from the opening is hinged to the end of the rod body 81. The first bolt 83 is connected to the fastener 82 by a thread. A first screw hole 821 is provided on the side wall of the fastener 82 to adapt to the first bolt 83. The distance H between the bottom surface of the first screw hole 821 and the bottom surface of the inner cavity of the fastener 82 is not less than the height of the waist beam 7 of this period, thereby ensuring that the first bolt 83 and the middle part of the fastener 82 can be separately arranged on both sides of the waist beam 7 of this period, thereby realizing a hoop connection. The end of the side wall of fastener 82, away from the opening, is provided with a corner structure 822 that adapts to the outer corner of the current waist beam 7. Corner structure 822 is L-shaped, and the outer wall of corner structure 822 is hinged to the end of rod body 81, so that corner structure 822 and rod body 81 are connected in a Y-shaped manner, thereby improving structural stability and preventing unbalanced loading. When fastener 82 is fastened to the surface of the current waist beam 7 from bottom to top, rod body 81 can apply a supporting force that is diagonally upward and directed toward the current slope guard plate 5 to the side of the bottom of fastener 82 away from the current slope guard plate 5, thereby achieving stable support, preventing torsional damage to the current waist beam 7, and preventing the problem of the first bolt 83 being unable to be unscrewed due to thread damage.

[0060] Reference Figure 6 and Figure 7 In conventional technology, the fastener 82 is usually fastened to the waist beam 7 from top to bottom, and the first bolt 83 is located at the bottom surface of the waist beam 7. Figure 6 If the rod 81 is connected to the bottom of the waist beam 7, the support force applied by the waist beam 7 to the fastener 82 is transmitted to the first bolt 83, causing the first bolt 83 and the bottom surface of the waist beam 7 to squeeze each other, resulting in wear of the thread of the first bolt 83; and, since the opening of the fastener 82 is downward, the rod 81 can only be connected to one of the side walls of the fastener 82, so that the rod 81 and the selected side wall are connected in an L shape, which has a lower load-bearing capacity than the Y-shaped connection, is prone to cause eccentric load, and is not conducive to the transmission of the support force. Figure 7If the rod 81 is connected to the top of the side wall of the current waist beam 7, the supporting force will be transmitted to the top corner position of the fastener 82. The top of this position lacks support, causing the fastener 82 and the current waist beam 7 to twist and deform, resulting in damage. Figure 7 If the rod body 81 is connected to the top of the side wall of the waist beam 7, the rod body 81 will block the first screw hole 821 from top to bottom, making it difficult for the first bolt 83 to be screwed into the first screw hole 821, which brings difficulties to the installation of the first bolt 83.

[0061] Reference Figure 4 and Figure 5 Step S26 includes the following steps: S261, fasten the fastener 82 from bottom to top on the bottom wall and side wall of the current waist beam 7, then screw the first bolt 83 into the inner cavity of the fastener 82 and tighten it. At this time, the first bolt 83 is located above the current waist beam 7 to prevent the first bolt 83 from bearing the support force from the rod body 81; S262, insert the end of the rod body 81 away from the fastening into the ground of the foundation pit 2.

[0062] Reference Figure 4 , step S262 includes the following steps: S2621, rotary excavating and forming a receiving pit 21 in the foundation pit 2;

[0063] S2622. An anchor plate is sleeved on the end of the rod body 81 away from the fastener 82, and then the end of the rod body 81 away from the fastener 82 and the anchor plate are inserted into the accommodating pit 21, and then concrete is poured into the accommodating pit 21; S2623. After the concrete in the accommodating pit 21 hardens, an abutment block is formed to abut the foundation pit 2, and the abutment block is used to place the end of the rod body 81 away from the fastener 82 downward, thereby improving the support reliability of this support assembly 8.

[0064] The end surface of the rod body 81 away from the fastener 82 is fixedly connected with a convex ring through an integral manner. The convex ring is used to abut the anchor plate, thereby improving the abutting force.

[0065] Reference Figure 3 The slope protection board 5 and the waist beam 7 of this period are respectively arranged on both sides of the slope protection pile 4 of this period, so that a clearance gap 51 for accommodating the fastener 82 is formed between the slope protection board 5 and the waist beam 7 of this period; the support assembly 8 of this period is placed between two adjacent slope protection columns of this period, so that the fastener 82 can be fastened to the surface of the waist beam 7 of this period from bottom to top without being hindered by the slope protection pile 4 of this period, avoiding structural conflict between the fastener 82 and the slope protection pile 4 of this period.

[0066] Reference Figure 8 The side wall of a single slope protection pile 4 is connected to two waist beams 7, namely a first waist beam 701 and a second waist beam 702 arranged below the first waist beam 701. The first waist beam 701 and the second waist beam 702 have the same length and cross-sectional dimensions, so there is no need to distinguish them during installation.

[0067] Reference Figure 8 , this period's support assembly 8 also includes a fastening member 84 and an abutting rod 85. The fastening member 84 is an N-shaped plate-like structure. The fastening member 84 is provided with a second screw hole at the side wall of the opening. A detachable second bolt 841 is threadedly connected to the second screw hole. The distance between the top surface of the second bolt 841 and the top surface of the inner cavity of the fastening member 84 is greater than the cross-sectional height of the waist beam 7 of this period. Therefore, when the second bolt 841 is screwed into the second screw hole and passes through the inner cavity of the fastening member 84, the middle part of the fastening member 84 and the second bolt 841 can be separately arranged on both sides of the waist beam 7 of this period, thereby achieving a hoop connection. An arc-shaped tooth structure 842 is provided on the outer wall of the middle part of the fastening member 84. Binding fins 843 are respectively provided on the left and right sides of the arc-shaped tooth structure 842. The fastening plate, the arc-shaped teeth and the binding fins 843 are fixedly connected in an integrated manner. One end of the abutting rod 85 is hinged to the rod body 81, and the other end is pressed onto the arc-shaped tooth structure 842 and is detachably connected to the fastening member 84. The abutment rod 85 is a straight rod structure, the lower surface of the abutment rod 85 is a first straight rack structure adapted to the arc-shaped tooth structure 842, and the top surface of the abutment rod 85 is provided with a second straight rack structure 851. Figure 10 The arc-shaped tooth structure 842 is in an upward convex arc shape, so it has greater compatibility with the pressing angle of the abutment rod 85, that is, when the abutment rod 85 and the first straight rack structure are pressed on the arc-shaped tooth structure 842 in an inclined state, the first straight rack structure can engage with the arc-shaped tooth structure 842 to achieve the pulling connection or abutment between the second waist beam 702 and the abutment rod 85. Figure 10 Since multiple slope protection structures of this phase need to be installed during the construction process, and the ground of the foundation pit 2 is uneven, after the ends of the rod bodies 81 at different positions are overlapped on the ground of the foundation pit 2, the hinge positions of the rod bodies 81 and the abutment rods 85 have different heights, and the abutment rods 85 will be pressed on the arc-shaped tooth structure 842 at different angles, and the abutment rods 85 are all tilted left or right based on the horizontal plane.

[0068] Reference Figure 4 、 Figure 5 and Figure 8Step S26 includes the following steps: S261, fasten the fastener 82 from bottom to top to the bottom wall and side wall of the first waist beam 701, then screw the first bolt 83 into the inner cavity of the fastener 82 and tighten it. At this time, the first bolt 83 is located above the first waist beam 701 to prevent the first bolt 83 from bearing the support force from the rod body 81; S262, insert the end of the rod body 81 away from the fastening into the ground of the foundation pit 2; S263, fasten the fastening piece 84 from top to bottom to the top surface and side wall of the second waist beam 702 Then screw the second bolt 841 into the inner cavity of the fastening part 84 and tighten it. At this time, the arc-shaped tooth structure 842 is located above the second waist beam 702; S264, rotate the abutment rod 85, press the first straight rack structure onto the fastening part 84, so that the first straight rack structure is engaged with the arc-shaped tooth structure 842; S265, use the wire 86 to bind the binding fins 843 on both sides to the abutment rod 85 respectively, so that the wire 86 is at the lower surface position of the binding fin 843 and the tooth groove position of the second straight rack structure 851.

[0069] If necessary, the soil layer is dug up and the position of the abutment block is fine-tuned to achieve the meshing of the first straight rack structure and the arc-shaped tooth structure 842 .

[0070] In step S265 , the iron wire 86 can be selectively crimped into the tooth groove of the second straight rack structure 851 , so that the iron wire 86 has a smaller single-loop circumference after being bundled, thereby improving the firmness of the bundle.

[0071] Reference Figure 8 The current support assembly 8 is arranged in a Y shape and connects two current waist beams 7 at the same time, thereby avoiding the stress concentration problem caused by connecting a single current waist beam 7, achieving uniform load-bearing, and improving the supporting capacity of the current slope protection piles 4 and the current slope protection boards 5, further compensating for the problem that the original slope protection piles 3 and the original waist beams 32 cannot provide sufficient tension to the current slope protection structure due to aging, thereby improving support safety and avoiding the occurrence of safety accidents such as support failure.

[0072] Reference Figure 9 and Figure 10 Since the arc-shaped tooth structure 842 is an upward convex arc, an accommodating gap 8431 is formed between the binding fin 843 and the abutment rod 85. The user bites the pliers on the outside of the accommodating gap 8431 and then clamps it, which can easily interrupt the wire 86; the accommodating gap 8431 is used to provide an accommodating space for the clamping closure of the pliers head.

[0073] Reference Figure 2The existing slope protection piles 3 are fixedly connected to the existing waist beams 32 with bolts. The tops of the existing slope protection piles 3 are also fixedly connected to the existing crown beams 31 with bolts (to ensure the integrity of the existing slope protection piles 3). During construction, the new crown beams 6 are installed at the same height as the original crown beams 31. This ensures that the two sides are at the same height after backfilling and avoids uneven loading. The tops of the new slope protection boards 5 are at the same height as the new crown beams 6 and are fixedly connected or abutted with bolts.

[0074] In the description of the present invention, it should be noted that the terms "up", "down", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0075] It should also be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "disposed," "installed," and "connected" should be understood broadly. For example, they may refer to fixed or detachable connections, or integral connections; mechanical or electrical connections; direct connections or connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0076] To sum up, for those skilled in the art, according to the guidance of the present invention, without departing from the principles and spirit of the present invention, changes, modifications, replacements and deformations made to the present invention still fall within the scope of protection of the present invention.

Claims

1. A construction method for deep foundation pit excavation on both sides of an existing building, characterized in that the steps include: S1. Excavating foundation pits (2) on both sides of the original building (1) simultaneously, with the excavation directions of the two foundation pits (2) being perpendicular to the original building (1) and facing each other left and right; S2. Stopping excavation when the original slope protection piles (3) around the original building (1) are exposed, and installing the current slope protection structure at the location of the original slope protection piles (3); the current slope protection structure includes the current slope protection piles (4), the current slope protection boards (5), the current crown beams (6), the current waist beams (7), and the current support components (8); The current support assembly (8) includes a rod body (81) and a fastener (82); the fastener (82) is a U-shaped plate-like structure, and the inner cavity of the fastener (82) can be adapted to be clamped to the side wall of the current waist beam (7); the end of the fastener (82) close to the opening is provided with a detachable first bolt (83) penetrating the side wall position, and the end of the side wall of the fastener (82) away from the opening is hinged to the end of the rod body (81); the current support assembly (8) also includes a fastener (84) and an abutting rod (85); the fastener (84) is an N-shaped plate-like structure, and the fastener (84) is provided with a second screw hole at the side wall position of the opening, and the second screw hole is connected to a detachable second bolt (841) by threading; An arc-shaped tooth structure (842) is provided on the outer wall of the middle portion of the fastening member (84), and binding fins (843) are provided on the left and right sides of the arc-shaped tooth structure (842). One end of the abutting rod (85) is hinged to the rod body (81), and the other end is pressed onto the arc-shaped tooth structure (842) and detachably connected to the fastening member (84). A first straight rack structure adapted to the arc-shaped tooth structure (842) is provided on the lower surface of the abutting rod (85), and a second straight rack structure (851) is provided on the top surface.

2. The method for excavating deep foundation pits on both sides of an existing building according to claim 1, characterized in that: In step S2, the installation steps of the slope protection structure of this phase include: S21, arranging the current-phase slope protection piles (4) at the edge of the foundation pit (2) close to the original slope protection piles (3), wherein the number of the current-phase slope protection piles (4) is equal to and corresponds one to one to the exposed original slope protection piles (3); S22, installing the current-phase slope protection plate (5) on the current-phase slope protection pile (4) at a side wall position close to the original slope protection pile (3); S23, installing the current crown beam (6) transversely on the top of the current slope protection pile (4); S24, installing the current waist beam (7) transversely in the middle of the side wall of the current slope protection pile (4); S25, using a first anchor cable (71) to pull the current waist beam (7) and the original waist beam (32) at the waist of the original slope protection pile (3); S26, installing the current phase support assembly (8) diagonally on the current phase waist beam (7), and the current phase support assembly (8) is located in the middle of the gap between two adjacent current phase slope protection piles (4); S27, backfilling part of the excavated earth into the gap between the original slope protection pile (3) and the current slope protection board (5).

3. The method for excavating deep foundation pits on both sides of an existing building according to claim 2, characterized in that: The current phase waist beam (7) and the current phase slope protection plate (5) are respectively arranged on both sides of the current phase slope protection pile (4).

4. The method for excavating deep foundation pits on both sides of an existing building according to claim 3, characterized in that: The slope protection plate (5) of this phase is provided with a plug-in hole for inserting the first anchor cable (71).

5. The method for excavating deep foundation pits on both sides of an existing building according to claim 4, characterized in that: In step S21, the installation steps of the slope protection piles (4) of this phase include: S211, rotary excavating a pile foundation hole in the foundation pit (2); S212, inserting the slope protection pile (4) of this phase into the pile foundation hole with the top end exposed; S213, filling the gap between the current slope protection pile (4) and the pile foundation hole with a filler.

6. The method for excavating deep foundation pits on both sides of an existing building according to claim 5, characterized in that: The first bolt (83) is connected to the fastener (82) via threads.

7. The method for excavating deep foundation pits on both sides of an existing building according to claim 6, characterized in that: The side wall of the fastener (82) is provided with a first screw hole (821) adapted to fit the first bolt (83), and the distance H between the bottom surface of the first screw hole (821) and the bottom surface of the inner cavity of the fastener (82) is not less than the height of the current waist beam (7).

8. The method for excavating deep foundation pits on both sides of an existing building according to claim 7, characterized in that: Two current-period waist beams (7) are connected to the side wall of a single current-period slope protection pile (4), and the two current-period waist beams (7) are respectively a first waist beam (701) and a second waist beam (702) arranged below the first waist beam (701); Step S26 includes the following steps: S261, fasten the fastener (82) from bottom to top to the bottom wall and side wall of the first waist beam (701), then screw the first bolt (83) into the inner cavity of the fastener (82) and tighten it, at which point the first bolt (83) is located above the first waist beam (701); S262: Insert the end of the rod body (81) away from the fastener (82) into the ground of the foundation pit (2).

9. The method for excavating deep foundation pits on both sides of an existing building according to claim 8, characterized in that: Step S262 includes the following steps: S2621, rotary excavating a receiving pit (21) in the foundation pit (2); S2622, inserting the end of the rod body (81) away from the fastener (82) into the receiving pit (21), and then pouring concrete into the receiving pit (21); S2623: After the concrete in the receiving pit (21) hardens, it forms an abutment block for abutting the foundation pit (2).

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