Excavation construction method for deep foundation pits on two sides of existing building

Abstract

The invention discloses an excavation construction method for deep foundation pits on the two sides of an existing building, and relates to the technical field of foundation pit construction.The excavation construction method comprises the steps that S1, foundation pits are excavated on the two sides of an original building at the same time, and the tunneling directions of the two foundation pits are perpendicular to the original building and are opposite left and right; and S2, when excavation is conducted till original slope protection piles on the periphery of the original building are exposed, excavation is stopped, and a current-period slope protection structure is installed at the positions of the original slope protection piles. The foundation pits are excavated on the two sides of the original building at the same time, the tunneling directions of the two foundation pits are opposite left and right, and the excavation progress is kept consistent, so that single-side settlement of the original building caused by unbalance loading is avoided, and the safety of the original building is ensured to the maximum extent. The current-period slope protection pile and the current-period slope protection plate are attached to the original slope protection pile for anchor cable pulling connection, the pulling connection structure is simplified, and the construction efficiency is further improved. The fastener is fastened to the surface of the current waist beam from bottom to top, so that the current waist beam is prevented from torsion damage, and the problem that threads of the first bolt are damaged and cannot be screwed out is solved.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit construction, and in particular to a deep foundation pit excavation construction method 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 space often face the problem of land shrinkage, which limits the horizontal planning of buildings and requires focusing on the full application of planned land, higher ground space or deeper basements. Therefore, it is necessary not only to solve the construction problems of deep foundation pits themselves, but also to minimize the adverse effects of deep foundation pit excavation on surrounding buildings. In traditional technologies, unilateral construction causes unilateral settlement of the original building, which is a common adverse effect during the operation process. 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 causes 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 deep foundation pit excavation construction method 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, the excavation directions of the two foundation pits are 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 the 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, and the number of the current slope protection piles is equal to and one-to-one corresponding to the original slope protection piles in the exposed state; S22, installing the current slope protection board at the side wall position of the current slope protection pile close to the original slope protection pile; S23, horizontally installing the current crown beam on the top of the current slope protection pile; 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 slope protection waist beam and 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 earth into the gap between the original slope protection pile and the current slope protection board.

[0007] As a further optimization scheme of the present invention, the current waist beam and the current slope protection board are arranged on both sides of the current slope protection piles.

[0008] 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.

[0009] 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.

[0010] 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; a removable first bolt is provided at the side wall position at one end of the fastener close to the opening, and the end of the fastener side wall away from the opening is hinged to the end of the rod body.

[0011] As a further optimization solution of the present invention, the first bolt is connected to the fastener via threads.

[0012] As a further optimization scheme of the present invention, the side wall of the fastener is provided with a first screw hole adapted to the first bolt, and the distance H between the bottom surface of the first screw hole and the bottom surface of the inner cavity of the fastener is not less than the height of the current waist beam.

[0013] 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, then screw the first bolt into the inner cavity of the fastener and tighten it, at which 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.

[0014] 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.

[0015] In summary, the present invention is beneficial in that: (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.

[0016] (2) The current slope protection piles and slope protection panels are connected with anchor cables by attaching them to the original slope protection piles, which improves the convenience of construction, simplifies the connection structure, and further improves the construction efficiency.

[0017] (3) The support assembly includes a rod and a fastener. When the fastener is fastened to the surface of the waist beam from bottom to top, the rod can apply a support force obliquely upward and directed to the slope guardrail to the side of the bottom of the fastener away from the slope guardrail, thereby achieving stable support, avoiding torsional damage to the waist beam, and avoiding the problem that the first bolt thread is damaged and cannot be unscrewed.

[0018] (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 the 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.

[0019] (5) If the ground of the foundation pit is uneven, then after the ends of the rods at different positions are overlapped on the ground of the foundation pit, the hinged positions of the rods and the abutting rods have different heights, so the abutting rods will be crimped 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 crimping 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

[0020] The present application is further described below with reference to the accompanying drawings: Figure 1 This is a top-down diagram of the state of excavating foundation pits on both sides of the original building at the same time; Figure 2 It is a front view schematic diagram of the connection structure between the original slope protection piles and the slope protection piles of this phase; Figure 3It is a top view schematic diagram of the connection structure of the current phase slope protection piles, the current phase slope protection boards, the current phase waist beam connection and the current phase support components; Figure 4 It is a front view schematic diagram of the connection structure between the current support assembly and the current waist beam; Figure 5 It is a schematic diagram of the vertical section structure of the fastener; Figure 6 It is a schematic diagram of the state in which the fastener is fastened on the waist beam of this period from top to bottom and the rod body is connected to the bottom end of the fastener; Figure 7 It is a schematic diagram of the state in which the fastener is fastened on the waist beam of this period from top to bottom and the rod body is connected to the top end of the fastener; Figure 8 It is a schematic diagram of the connection structure between the fastening member and the abutment rod; Fig. 9 To accommodate the gap location and structural schematic diagram; Fig.10 It is a schematic diagram of the structure in which the abutment rod is connected to the buckle piece in an inclined shape.

[0021] In the figure, 1. Original buildings; 2. Foundation pit; 21. Accommodation pit; 3. Original slope protection piles; 31. Original crown beam; 32. Original waist beam; 4. Slope protection piles in this period; 5. This phase of slope protection board; 51. Give way clearance; 6. Crown beam of this issue; 7, current waist beam; 701, first waist beam; 702, second waist beam; 71, first anchor cable; 72, second anchor cable; 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 tooth structure; 843. Binding fins; 8431. Accommodating gap; 85. Abutment rod; 851. Second straight rack structure; 86. Iron wire. DETAILED DESCRIPTION

[0022] Based on the above structural features of the present application, the implementation methods of the present application are further described: Reference Figure 1-2 This embodiment provides a deep foundation pit excavation construction method on both sides of an existing building, the steps comprising: S1, excavating foundation pits 2 on both sides of the original building 1 at the same time. The excavation directions of the two foundation pits 2 are perpendicular to the original building 1; the two foundation pits 2 are excavated in a form of from far to near, that is, 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, so as to avoid unilateral settlement of the original building 1 due to eccentric loading.

[0023] 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.

[0024] Reference Figure 1-2 The original slope protection piles 3 are slope protection piles inserted into the soil layer during the construction of the foundation of the original building 1, and then buried underground with the backfill of the moving earth.

[0025] Reference Figure 1-2 The slope protection structure of this phase includes slope protection piles 4 of this phase, slope protection boards 5 of this phase, crown beams 6 of this phase, waist beams 7 of this phase and support components 8 of this phase. The slope protection piles 4 of this phase, slope protection boards 5 of this phase, crown beams 6 of this phase, waist beams 7 of this phase and support components 8 of this phase work together to support the edge sidewalls of the foundation pit 2 of this phase, thereby avoiding edge collapse and improving construction safety.

[0026] Reference Figure 1 to Figure 3 In step S2, the installation steps of the slope protection structure in this phase include: 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 and corresponds one to one to the original slope protection piles 3 in an exposed state.

[0027] S22, installing 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, the current slope protection pile 4 is a prefabricated reinforced concrete structure, and a first sleeve is embedded in the side wall of the current slope protection pile 4 during prefabrication, and the first sleeve is fixedly connected to the steel mesh in the current slope protection pile 4. The user fastens the steel plate and the current slope protection pile 4 with bolts, and the bolts are tightened in the first sleeve.

[0028] S23, the current crown beam 6 is transversely installed on the top of the current slope protection pile 4. The current crown beam 6 is a steel beam; the top of the current slope protection pile 4 is embedded with a second sleeve during prefabrication, and the second sleeve is fixedly connected to the steel mesh in the current slope protection pile 4. The user fastens the current crown beam 6 and the current slope protection pile 4 with bolts, and the bolts are tightened in the second sleeve.

[0029] 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, and the third sleeve is fixedly connected to the steel mesh in the current slope protection pile 4. The user fastens the current waist beam 7 and the current slope protection pile 4 with bolts, and the bolts are tightened in the third sleeve.

[0030] S25, use the first anchor cable 71 to pull the current slope protection waist beam to the original waist beam 32 at the waist of the original slope protection pile 3. If the original slope protection pile 3 cannot apply enough tension to the current slope protection pile 4 (for example, the original slope protection pile 3 and the pile foundation hole are loosened due to aging, or the original slope protection pile 3 and the original waist beam 32 are loosened due to aging), the second anchor cable 72 is installed after the first anchor cable 71 is installed; the second anchor cable 72 is used to assist the first anchor cable 71 in bearing force, and jointly pull the current slope protection board 5 and the current waist beam 7 together.

[0031] 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 of the gap between two adjacent current slope protection piles 4; S27, backfill 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 soil and the first anchor cable 71 is tightened.

[0032] The current waist beam 7 and the current slope protection board 5 are 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.

[0033] In this period, the slope protection board 5 is provided with a plurality of plug-in holes for inserting 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 state after tensioning, thereby improving the pulling stability.

[0034] In step S21, the installation steps of the slope protection pile 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 exposed; S213, filling the gap between the slope protection pile 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 pile 4 of this phase is completed.

[0035] In step S25, the installation steps of the second anchor cable 72 include: S251, rotary digging a connection hole in the soil layer 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 making the second anchor cable 72 taut.

[0036] Reference Figure 3 to Figure 5The support assembly 8 of this period 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 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 one 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 threads. The side wall of the fastener 82 is provided with a first screw hole 821 adapted to 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 waist beam 7 of this period, so as to ensure that the first bolt 83 and the middle part of the fastener 82 can be arranged on both sides of the waist beam 7 of this period, so as to achieve a hoop connection. The end of the side wall of the fastener 82 away from the opening is provided with a corner structure 822 adapted to the outer corner of the current waist beam 7. The corner structure 822 is an L-shaped structure. The outer wall of the corner structure 822 is hinged to the end of the rod body 81, and the corner structure 822 and the rod body 81 are connected in a Y shape, thereby improving the structural stability and avoiding eccentric load. When the fastener 82 is fastened to the surface of the current waist beam 7 from bottom to top, the rod body 81 can apply a support force that is obliquely upward and directed to the current slope protection board 5 to the side position of the bottom of the fastener 82 away from the current slope protection board 5, thereby achieving stable support, avoiding torsional damage to the current waist beam 7, and avoiding the problem that the first bolt 83 cannot be screwed out due to damage to the thread.

[0037] Reference Figure 6 and Figure 7 In the conventional technology, the fastener 82 is usually fastened on 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 body 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, so that the first bolt 83 and the bottom surface of the waist beam 7 are squeezed against each other, resulting in thread wear of the first bolt 83; and, the opening of the fastener 82 is downward, so the rod body 81 can only be connected to one of the side walls of the fastener 82, so that the rod body 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 7 If 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 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.

[0038] Reference Figure 4 and Figure 5Step 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 supporting 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.

[0039] Reference Figure 4 , step S262 includes the following steps: S2621, rotary excavating and forming a receiving pit 21 in the foundation pit 2; 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 receiving pit 21, and then concrete is poured into the receiving pit 21; S2623. After the concrete in the receiving pit 21 hardens, an abutment block for abutting the foundation pit 2 is formed, and the abutment block is used to place the end of the rod body 81 away from the fastener 82 to sink, thereby improving the support reliability of the current support assembly 8.

[0040] The end surface of the rod body 81 away from the fastener 82 is integrally fixedly connected with a convex ring, and the convex ring is used to abut against the anchor plate, thereby improving the abutting force.

[0041] Reference Figure 3 The slope protection board 5 and the waist beam 7 are arranged on both sides of the slope protection pile 4, so that a clearance gap 51 for accommodating the fastener 82 is formed between the slope protection board 5 and the waist beam 7; the support assembly 8 is placed between two adjacent slope protection columns, so that the fastener 82 can be fastened to the surface of the waist beam 7 from bottom to top without being hindered by the slope protection pile 4, avoiding structural conflict between the fastener 82 and the slope protection pile 4.

[0042] Reference Figure 8 The side wall of a single slope protection pile 4 is connected with two waist beams 7, which are 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 size, so there is no need to distinguish them during installation.

[0043] Reference Figure 8, the support assembly 8 of this period also includes a buckle 84 and an abutment rod 85. The buckle 84 is an N-shaped plate-like structure, and the buckle 84 is provided with a second screw hole at the position of the opening side wall, and a detachable second bolt 841 is connected in the second screw hole by threading. The distance between the top surface of the second bolt 841 and the top surface of the inner cavity of the buckle 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 penetrates the inner cavity of the buckle 84, the middle part of the buckle 84 and the second bolt 841 can be separately arranged on both sides of the waist beam 7 of this period, so as to achieve hoop connection. The outer wall of the middle part of the buckle 84 is provided with an arc-shaped tooth structure 842, and the left and right sides of the arc-shaped tooth structure 842 are respectively provided with binding fins 843, and the buckle plate, the arc-shaped teeth and the binding fins 843 are fixedly connected in an integrated manner. One end of the abutment rod 85 is hinged to the rod body 81, and the other end is pressed on the arc-shaped tooth structure 842 and is detachably connected to the buckle 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. Fig.10 The arc-shaped tooth structure 842 is in an upward convex arc shape, so it has greater compatibility with the crimping angle of the abutment rod 85, that is, when the abutment rod 85 and the first straight rack structure are crimped on the arc-shaped tooth structure 842 in an inclined state, the first straight rack structure can mesh 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. Fig.10 Since multiple slope protection structures of this period 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 hinged 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 inclined to the left or right based on the horizontal plane.

[0044] Reference Figure 4 , Figure 5 and Figure 8Step S26 includes the following steps: S261, fasten the fastener 82 from bottom to top on 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 member 84 from top to bottom on the top surface and side wall of the second waist beam 702 S264, rotate the abutment rod 85 to press the first straight rack structure onto the fastening member 84, so that the first straight rack structure engages with the arc-shaped tooth structure 842; S265, use the iron wire 86 to bind and connect the binding fins 843 on both sides with the abutment rod 85 respectively, so that the iron 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.

[0045] If necessary, dig up the soil layer and fine-tune the position of the abutment block to achieve the meshing of the first straight rack structure and the arc-shaped tooth structure 842.

[0046] In step S265, the iron wire 86 can be selectively crimped into the tooth groove of the second spur rack structure 851, so that the iron wire 86 has a smaller single-circle circumference after being bundled, thereby improving the firmness of the bundle.

[0047] 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, and 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 the support safety and avoiding the occurrence of safety accidents such as support failure.

[0048] Reference Fig. 9 and Fig.10 Since the arc-shaped tooth structure 842 is an upward convex arc, a receiving gap 8431 is formed between the binding fin 843 and the abutment rod 85. The user bites the pliers on the outside of the iron wire 86 at the receiving gap 8431 and then clamps it, which can conveniently interrupt the iron wire 86; the receiving gap 8431 is used to provide a receiving space for the clamping closure of the pliers head.

[0049] Reference Figure 2The original slope protection pile 3 is fixedly connected to the original waist beam 32 by bolts, and the top of the original slope protection pile 3 is fixedly connected to the original crown beam 31 by bolts (in order to ensure the integrity of several original slope protection piles 3); during construction, the current crown beam 6 is installed at the same height as the original crown beam 31, so that the two sides are at the same height after the soil and stone are backfilled to avoid eccentric loading. The top of the current slope protection board 5 is at the same height as the current crown beam 6 and is fixedly connected or abutted by bolts.

[0050] In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0051] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] 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, the changes, modifications, substitutions and deformations made to the present invention still fall within the protection scope of the present invention.

Claims

1. A method for excavating deep foundation pits 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) at the same time, wherein the excavation directions of the two foundation pits (2) are perpendicular to the original building (1) and opposite to each other; S2. When the original slope protection piles (3) around the original building (1) are exposed, stop excavating and install the slope protection structure of the current phase at the position of the original slope protection piles (3); The current phase slope protection structure comprises current phase slope protection piles (4), current phase slope protection boards (5), current phase crown beams (6), current phase waist beams (7) and current phase support components (8).

2. The deep foundation pit excavation construction method on both sides of an existing building according to claim 1 is characterized in that: In step S2, the installation steps of the slope protection structure in 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 original slope protection piles (3) in an exposed state; 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 slope protection waist beam to 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 deep foundation pit excavation construction method on both sides of an existing building according to claim 2 is characterized in that: The current-stage waist beam (7) and the current-stage slope protection board (5) are arranged on both sides of the current-stage slope protection pile (4).

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

5. The deep foundation pit excavation construction method on both sides of an existing building according to claim 4 is characterized in that: In step S21, the steps of laying out 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 deep foundation pit excavation construction method on both sides of an existing building according to claim 5 is characterized in that: The current support assembly (8) comprises 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); a detachable first bolt (83) is provided at the side wall position of the fastener (82) at one 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).

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

8. The method for excavating deep foundation pits on both sides of an existing building according to claim 7, 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).

9. The method for excavating deep foundation pits on both sides of an existing building according to claim 8, characterized in that: Step S26 includes the following steps: S261, fastening the fastener (82) from bottom to top on the bottom wall and side wall of the current waist beam (7), and then screwing the first bolt (83) into the inner cavity of the fastener (82) and tightening it, at which point the first bolt (83) is located above the current waist beam (7); S262, inserting the end of the rod body (81) away from the buckle into the ground of the foundation pit (2).

10. The method for excavating deep foundation pits on both sides of an existing building according to claim 9, 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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