Construction method for in-situ addition of basement to existing connected silos

Abstract

The present invention discloses a construction method for in-situ adding a basement to an existing connected silo. The discharge hopper and floor of the existing connected silo are demolished, the foundation pit retaining structure, the newly added pile foundation and the steel column above it are constructed, brackets and vertical embedded parts are installed on the steel column, the core raft and the pile cap foundation are constructed to form a connection, soil extraction holes and lifting holes are reserved on the core raft, a lifting mechanism is installed, a suspension line is connected, the connection between the pile cap foundation and the existing pile foundation is cut off, the bolts between the bracket and the steel column are removed, the core raft is lifted through the lifting mechanism and the suspension line, the bolts between the bracket and the steel column are connected, the peripheral raft and the core raft are constructed to form a top plate, the steel column above the top plate is cut off, a track-type soil extraction device is installed in the existing connected silo, the basement structure is constructed, and the newly added pile foundation and the steel column are supplemented and the floor slab is closed at the soil extraction hole. The construction of the present invention is safe, reliable, has a high soil excavation efficiency, and is applicable to the underground space expansion of existing connected silos.

Description

Technical Field

[0001] The present invention relates to the technical field of construction engineering, and particularly relates to a construction method for in-situ adding a basement to an existing connected silo. Background Art

[0002] In order to expand the underground space, in the construction method of adding a basement to an existing building such as an existing historical protection building, its foundation is generally a shallow foundation. Usually, a tray structure is formed by a wall sandwich beam and a wall-piercing beam together for foundation underpinning to construct the structure of the newly added basement. However, for industrial buildings such as silos, since pile foundations are generally provided under the deep foundation caps, it increases the difficulty of underpinning the existing structure. On the one hand, since the outer walls of such structures are made of concrete materials, large-area chiseling and opening of the silo walls cannot be carried out to form a tray structure composed of a wall sandwich beam and a wall-piercing beam, otherwise the structure will be unevenly stressed due to load eccentricity, further causing the structure to be damaged or the foundation to settle unevenly. On the other hand, since its foundation generally adopts the form of a pile foundation and there are no walls or columns in the middle, the construction method of the tray structure cannot be used to complete the foundation underpinning process, thus bringing difficulties to the construction of in-situ adding a basement. In addition, when large-area underground excavation is carried out for existing industrial heritage buildings such as connected silos, due to the low soil excavation efficiency of the top-down method, the construction efficiency of the project will be reduced to a certain extent. Summary of the Invention

[0003] The purpose of the present invention is to provide a construction method for in-situ adding a basement to an existing connected silo to solve the problems that the traditional tray structure cannot realize the foundation underpinning of the existing connected silo and the low soil excavation efficiency during the excavation of the added basement.

[0004] To solve the above technical problems, the technical solution provided by the present invention is: a construction method for in-situ adding a basement to an existing connected silo, including:

[0005] Demolish the discharge funnel and floor inside the existing connected silo;

[0006] Construct a foundation pit retaining structure around the existing connected silo;

[0007] Construct a new pile foundation and the steel columns above it inside the foundation pit retaining structure and the existing connected silo;

[0008] After the foundation pit retaining structure and the new pile foundation reach the design strength, excavate the soil symmetrically within the foundation pit retaining structure to the elevation of the lower surface of the bearing platform foundation of the existing connected silo, exposing the bearing platform foundation connected to the existing connected silo;

[0009] Install a bracket on the steel column below the elevation of the lower surface of the bearing platform foundation through bolts;

[0010] Install vertical embedded parts on the corbel, making the upper end of the vertical embedded parts higher than the pile cap foundation;

[0011] Continue to excavate the soil to expose the lower surface of the corbel and the existing pile foundation below the pile cap foundation. Arrange raft steel bars on the pile cap foundation to extend beyond the periphery of the existing connected silos and pour concrete to connect the pile cap foundation with the concrete to form a core raft on the corbel. A soil extraction hole is reserved on the core raft, and a lifting hole is reserved at the node of the core raft and the steel column. The upper end of the vertical embedded part is exposed on the upper surface of the core raft;

[0012] Install a lifting mechanism at the upper end of the steel column within the coverage area of the core raft to be constructed. Connect the lifting mechanism with the vertical embedded part through a plumb line. Cut off the connection between the pile cap foundation and the existing pile foundation, remove the bolts connecting the corbel and the steel column, and control the lifting mechanism to lift the core raft upward along the steel column through the lifting hole by means of the plumb line and its connected vertical embedded part and corbel. After the core raft is lifted to the specified height, connect the corbel and the steel column with bolts;

[0013] Construct a peripheral raft of reinforced concrete structure between the core raft and the foundation pit retaining structure, and seal the lifting holes on the core raft, so that the peripheral raft and the core raft form a basement roof with a soil extraction hole;

[0014] After the basement roof reaches the design strength, remove the lifting mechanism and cut off the steel column above the basement roof;

[0015] Install a track-type soil extraction device at the position of the soil extraction hole in the existing connected silos. The track-type soil extraction device includes a conveyor belt that straddles the soil extraction hole on the same straight line and is arranged on the basement roof and extends beyond the existing connected silos, a track beam that is perpendicular to the conveyor belt and straddles the soil extraction hole above the conveyor belt, and a soil transport box that moves horizontally along the length direction of the track beam and moves up and down relative to the track beam;

[0016] Continue to excavate the soil downward and load it into the soil transport box. After loading, the soil transport box is lifted upward along the soil extraction hole and then moves horizontally relative to the track beam to transport the soil transport box or the soil in it out of the existing connected silos through the conveyor belt, and construct the basement structure;

[0017] After the basement structure reaches the designed number of floors, supplement and construct the new pile foundation and the steel column above it in the basement structure through the soil extraction hole, and seal the soil extraction hole in the floor of the basement structure with the soil extraction hole by using a closed floor of reinforced concrete structure to form a complete floor.

[0018] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention, except for the steel columns at the outermost periphery of the foundation pit retaining structure, the upper elevations of the remaining steel columns are on the same plane, and the upper end of the outermost steel column is lower than the upper ends of the remaining steel columns.

[0019] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention, the upper elevations of all the vertical embedded parts are on the same plane.

[0020] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention,

[0021] Before cutting off the connection between the pile cap foundation and the existing pile foundation, the core raft is pre-lifted by a lifting mechanism, and the core raft is pre-tightened by the lifting mechanism.

[0022] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention, the lifting mechanism includes a motor and the suspension line.

[0023] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention, the corbels, vertical embedded parts, lifting mechanism and suspension line are all arranged on both symmetric sides of the steel column.

[0024] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention, vertical temporary supports are arranged between the floors around the soil extraction opening of the basement structure. After the floor slab at the soil extraction opening is constructed and reaches the design strength, the vertical temporary supports between the floors are removed.

[0025] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention, the existing connected silo is strengthened before demolishing the discharge funnel inside the existing connected silo.

[0026] Further, for the construction method of in-situ adding a basement to an existing connected silo provided by the present invention, a safety monitoring device is installed on the existing connected silo before demolishing the discharge funnel inside the existing connected silo, which is used to monitor the stress and deformation conditions of the existing connected silo to ensure the construction safety of in-situ adding a basement to the existing connected silo.

[0027] Compared with the prior art, the beneficial effects of the construction method of in-situ adding a basement to an existing connected silo provided by the present invention are as follows:

[0028] By connecting the pile cap foundation of the existing connected silos with the newly added core raft, cutting off the connection between the existing pile foundation and the pile cap foundation, and connecting the existing connected silos through the core raft and its steel columns, the overall replacement of the existing connected silos is carried out through the core raft, ensuring the safety of adding a basement in-situ to the existing connected silos and maximizing the retention of the original architectural appearance of the existing connected silos.

[0029] The overall replacement of the existing connected silos through the core raft and steel columns is applicable to existing buildings such as existing connected silos, avoiding the situation where the tray structure system formed by the sandwich wall beam and the wall-piercing beam cannot be applied to existing buildings such as existing connected silos.

[0030] The core raft is lifted through the lifting mechanism, suspension wire, corbel and vertical embedded parts, facilitating the overall coordinated lifting construction, enabling long-distance lifting, ensuring the safety and stability of the core raft during the lifting process, and overcoming the problems of large coordination difficulty of jacks and inability to achieve long-distance jacking.

[0031] By driving the existing connected silos to be lifted synchronously with the core raft to a predetermined height, the working space height of the basement construction is increased, the construction difficulty is reduced, the amount of excavation and the excavation depth can also be reduced, and the construction efficiency of adding a basement in-situ to the existing connected silos is improved.

[0032] By excavating soil in a symmetric manner, the problem of the collapse of the existing connected silos caused by uneven excavation is avoided.

[0033] The soil discharging efficiency after excavation is improved through the track soil-taking device. Brief Description of the Drawings

[0034] Figure 1 is a schematic elevation structure diagram of an existing connected silo without a basement structure;

[0035] Figure 2 is to demolish Figure 1 the elevation structure diagram of the discharge funnel and the floor in

[0036] Figure 3 is on the basis of Figure 2 the elevation structure diagram of constructing the foundation pit enclosure structure, the newly added pile foundation and the steel column above it;

[0037] Figure 4 is on the basis of Figure 2 the plan structure diagram of constructing the foundation pit enclosure structure, the newly added pile foundation and the steel column above it;

[0038] Figure 5 is on the basis of Figure 4 the elevation structure diagram of symmetrically excavating the soil to the elevation of the lower surface of the pile cap foundation;

[0039] Figure 6 It is a schematic elevation view of the structure for installing a bracket on a steel column.

[0040] Figure 7 It is a schematic elevation view of the structure for installing a vertical embedded part on the bracket.

[0041] Figure 8 It is a schematic elevation view of the structure for constructing the core raft foundation.

[0042] Figure 9 It is a schematic plan view of the structure for constructing the core raft foundation.

[0043] Figure 10 It is a schematic elevation view of the structure for installing a lifting mechanism at the upper end of the steel column and installing a suspension wire between it and the vertical embedded part.

[0044] Figure 11 It is a schematic elevation view of the structure for cutting off the connection between the bearing platform foundation and the existing pile foundation and connecting the existing connected silos to the core raft foundation, steel column and newly added pile foundation.

[0045] Figure 12 It is a schematic elevation view of the structure for lifting the core raft foundation to a specified height by the lifting mechanism.

[0046] Figure 13 It is a schematic plan perspective view of the structure for symmetrically excavating the soil body continuously after lifting the core raft foundation.

[0047] Figure 14 It is a schematic elevation view of the structure for constructing the peripheral raft foundation to form the basement roof with a soil extraction opening.

[0048] Figure 15 It is a schematic plan view of the structure for constructing the peripheral raft foundation to form the basement roof with a soil extraction opening.

[0049] Figure 16 It is a schematic elevation view of the structure for cutting off the steel column above the basement roof and installing a track-type soil extraction device.

[0050] Figure 17 It is a schematic plan view of the structure for installing a track-type soil extraction device on the existing connected silos.

[0051] Figure 18 It is a schematic elevation view of the first basement floor of the basement structure constructed by the top-down method.

[0052] Figure 19 It is a schematic elevation view of the second basement floor of the basement structure constructed by the top-down method.

[0053] Figure 20 It is a schematic elevation view of the structure for supplementing the construction of pile foundation, steel column and closed floor at the soil extraction opening of the basement structure.

[0054] Figure 21 It is a schematic three-dimensional structure diagram of an orbital soil-taking device;

[0055] Figure 22 It is a schematic structural diagram of installing a bracket on a steel column through bolts;

[0056] Figure 23 It is a schematic structural diagram of installing a bracket and a vertical embedded part on a steel column through bolts;

[0057] Figure 24 It is a schematic structural diagram of a node after the force transfer of an existing connected silo is completed;

[0058] Figure 25 It is Figure 24 The enlarged structural diagram of the left node in;

[0059] As shown in the figure:

[0060] 100. Existing connected silo, 101. Raft foundation, 102. Existing pile foundation, 103. Floor, 104. Discharge hopper, 105. Foundation pit retaining structure, 106. Steel column, 107. Bracket, 108. Vertical embedded part, 109. Raft slab steel bars, 110. Core raft slab, 111. Soil-taking hole, 112. Hoisting hole, 113. Hoisting mechanism, 114. Suspension line, 115. Peripheral raft slab, 116. Basement roof, 117. Track beam, 118. Soil-transporting box, 119. Conveyor belt, 120. Tippler, 121. Basement structure, 122. Vertical temporary support, 123. Newly added pile foundation, 124. Enclosed floor slab, 125. Overhead crane, 126. Suspension rope, 127. Bolt;

[0061] 200. Soil mass;

[0062] 300. Excavator. Specific implementation manners

[0063] The present invention will be described in detail below with reference to the accompanying drawings: According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0064] Please refer to Figures 1 to 25 , an embodiment of the present invention provides a construction method for in-situ adding a basement to an existing connected silo, which may include the following steps:

[0065] Step 401, please refer to Figures 1 to 2 , demolish the discharge hopper 104 and the floor 103 inside the existing connected silo 100.

[0066] Step 402, please refer toFigures 3 to 4 , construct a foundation pit retaining structure 105 around the existing connected silos 100.

[0067] Step 403, please refer to Figures 3 to 4 , construct a new pile foundation 123 and the steel columns 106 above it within the foundation pit retaining structure 105 and the existing connected silos 100. Preferably, except for the steel columns 106 at the outermost periphery of the foundation pit retaining structure 105, the elevations of the upper surfaces of the remaining steel columns 106 are on the same plane, and the upper ends of the outermost steel columns 106 are lower than the upper ends of the remaining steel columns. In the figure, it is exemplified that the elevation of the upper end of the outermost steel column 106 is the same as the ground level. The steel columns 106 and the new pile foundation 123 can be constructed in the distribution pattern of the row-column matrix shown in the figure.

[0068] Step 404, please refer to Figure 5 , after the foundation pit retaining structure 105 and the steel columns 106 reach the design strength, excavate the soil symmetrically within the foundation pit retaining structure 105 to the elevation of the lower surface of the pile cap foundation 101 of the existing connected silos 100, exposing the pile cap foundation 101 connected to the existing connected silos 100. The excavator 300 can be used to excavate the soil symmetrically, and all subsequent steps are carried out in a symmetrical manner to avoid the problem that the existing connected silos 100 may collapse due to uneven excavation.

[0069] Step 405, please refer to Figure 6 and Figure 22 , install the corbels 107 on the steel columns 106 below the elevation of the lower surface of the pile cap foundation 101 through bolts 128. The elevations of all the corbels 107 can be equal.

[0070] Step 406, please refer to Figure 7 and Figure 23 , install the vertical embedded parts 108 on the corbels 107 so that the upper ends of the vertical embedded parts 108 are higher than the pile cap foundation 101. The vertical embedded parts 108 can be, for example, screw rods with lifting rings, and the screw rods are connected to the corbels 107 through nuts. The upper ends of all the vertical embedded parts 108 are on the same plane.

[0071] Step 407, please refer to Figures 8 to 9, continue to excavate the soil to expose the lower surface of the corbel 107 and the existing pile foundation 102 under the pile cap foundation 101. Arrange raft steel bars 109 on the pile cap foundation 101 to extend beyond the periphery of the existing connected silos 100 and pour concrete to connect the pile cap foundation 101 with the concrete to form a core raft 110 on the corbel 107. A soil extraction hole 111 is reserved on the core raft 110, and a lifting hole 112 is reserved at the node of the core raft 110 and the steel column 106. The upper end of the vertical embedded part 108 is exposed on the upper surface of the core raft 110. The elevations of the upper ends of all vertical embedded parts 101 are equal.

[0072] Step 408, please refer to Figures 10 to 13 , Figures 24 to 25 , install a lifting mechanism 113 at the upper end of the steel column 106 within the coverage area of the core raft to be constructed. Connect the lifting mechanism 113 with the vertical embedded part 108 through a suspension wire 114. Cut off the connection between the pile cap foundation 101 and the existing pile foundation 102, remove the bolts 128 connecting the corbel 107 and the steel column 106, and control the lifting mechanism 113 to lift the core raft 110 and the existing connected silos 100 thereon along the steel column 106 through the suspension wire 114, the vertical embedded part 108 and the corbel 107 via the lifting hole 112. After the core raft 110 is lifted to the specified height, connect the corbel 107 and the steel column 106 with bolts 128. The lifting mechanism may include a motor, a suspension wire 114 and a wire reel, etc., that is, the lifting mechanism may be a winch or a hoist. The suspension wire 114 may be a chain, a steel wire rope, etc. By synchronously lifting the core raft 110 and driving the existing connected silos 100 to a predetermined height, the working space height of the basement construction is increased, the construction difficulty is reduced, and the construction efficiency of adding a basement to the existing connected silos 100 in situ is improved. Lifting the core raft 110 through the lifting mechanism 113, the suspension wire 114, the corbel 107 and the vertical embedded part 108 is convenient for overall coordinated lifting construction, can achieve long-distance lifting, ensures the safety and stability of the lifting process of the core raft 100, and overcomes the problems of great coordination difficulty of jacks and inability to achieve long-distance jacking.

[0073] Step 409, please refer to Figures 14 to 16 , construct a peripheral raft 115 of reinforced concrete structure between the core raft 110 and the foundation pit retaining structure 105, and seal the lifting hole 112 on the core raft 110 so that the peripheral raft 115 and the core raft 110 form a basement roof 116 with a soil extraction hole 111. The peripheral raft 115 and the core raft 110 are preferably connected by reinforcement measures such as planting bars to ensure reliable connection and form an integral whole.

[0074] Step 410, please refer to Figures 16 to 17, after the basement top slab 116 reaches the design strength, the lifting mechanism 113 is removed, and the steel columns 106 above the basement top slab 116 are cut off. The steel columns 106 above the basement top slab 116 are cut off to make the upper surface of the truncated steel columns 106 flush with the basement top slab 116.

[0075] Step 411, please refer to Figures 16 to 17 , at the position of the soil-taking hole 111 in the existing connected silos 100, a track-type soil-taking device is installed. The track-type soil-taking device includes a conveyor belt 119 that straddles the soil-taking hole 111 on the same straight line and extends out of the existing connected silos 100 on the basement top slab 116, a track beam 117 that is perpendicular to the conveyor belt 119 and straddles the soil-taking hole 111 above the conveyor belt 119, and an earth-transporting box 118 that moves horizontally along the length direction of the track beam 117 and moves up and down relative to the track beam 117. Please refer to Figure 21 , the track-type soil-taking device may further include a crane 125 that moves horizontally on the track beam 117. The crane 125 is connected to the earth-transporting box 118 through a lifting rope 126. The earth-transporting box 118 is lifted and lowered through the soil-taking hole 111.

[0076] Step 412, please refer to Figures 18 to 19 , continue to excavate the soil downward and load it into the earth-transporting box 118. After loading, the earth-transporting box 118 is lifted upward through the soil-taking hole 111 and then moves horizontally relative to the track beam 117 to transport the earth-transporting box 118 or the soil therein out of the existing connected silos 100 through the conveyor belt 119, and the basement structure 121 is constructed. To facilitate soil transportation, a tipping truck 120 may be provided at the discharge end of the conveyor belt 119. To facilitate loading the soil onto the tipping truck 120, the discharge end of the conveyor belt 119 may be supported by a frame to load the soil at a height higher than the height of the tipping bucket of the tipping truck 120. Figure 19 Two basement structures 121 are exemplified, but it is not limited to two layers and can be adjusted according to requirements. Figures 18 to 19 The reverse construction method of the basement structure 121 is exemplified, and the forward construction method can also be used for the basement structure 121. Each basement structure 121 includes a structural floor slab and structural columns.

[0077] Step 413, please refer to Figure 20 , after the basement structure 121 reaches the designed number of floors, new pile foundations 123 and the steel columns 106 above them are additionally constructed in the basement structure 121 through the soil-taking hole 111, and the soil-taking hole is closed by a closed floor slab 124 of reinforced concrete structure on the floor slab of the basement structure 121 with the soil-taking hole 111 to form a complete floor slab. That is, the floor slab with the soil-taking hole 111 is complemented and constructed.

[0078] Step 414, please refer to Figure 20, remove the bracket 107 on the steel column 106 and the vertical embedded part 108 thereon.

[0079] The construction method for in-situ adding a basement to an existing connected silo provided by the embodiment of the present invention forms a connection between the bearing platform foundation of the existing connected silo and the newly added core raft, cuts off the connection between the existing pile foundation and the bearing platform foundation, forms a connection for the existing connected silo through the core raft and its steel columns, and performs an overall underpinning of the existing connected silo through the core raft, ensuring the safety of in-situ adding a basement to the existing connected silo and maximizing the retention of the original architectural appearance of the existing connected silo. The overall underpinning of the existing connected silo through the core raft and steel columns is applicable to existing buildings such as existing connected silos, avoiding the situation where the tray structure system formed by the sandwich wall beam and the through-wall beam is not applicable to existing buildings such as existing connected silos.

[0080] Please refer to Figures 10 to 11 , in order to achieve the horizontal lifting of the core raft 110 and the existing connected silo 100 thereon, in the construction method for in-situ adding a basement to an existing connected silo provided by the embodiment of the present invention, in step 408, before cutting off the connection between the bearing platform foundation 101 and the existing pile foundation 102, the core raft 110 is pre-lifted by the lifting mechanism 113, and the core raft 110 is pre-tightened through the lifting mechanism 113. Pre-lifting can avoid the problem that the suspension line 114 connected between the lifting mechanism 113 and the vertical embedded part 108 is not tight, resulting in the non-horizontal synchronous lifting of the core raft 110 and the existing connected silo 100 and causing the risk of tipping, improving the lifting safety of the core raft 110 and the existing connected silo 100. For the convenience of synchronous coordinated control of each lifting mechanism 113, it is required that the upper ends of the steel columns 106 of each lifting mechanism 113 have the same elevation, the installation elevation of the brackets 107 is the same, and the elevation of the upper ends of the vertical embedded parts 108 is the same. When the elevations of the new piles 106, brackets 107, and vertical embedded parts 108 are not equal, the suspension line 114 can be pre-tightened through the lifting mechanism 113.

[0081] Please refer to Figures 11 to 12 , in order to improve the stability of the existing connected silo 100 during the lifting process, in the construction method for in-situ adding a basement to an existing connected silo provided by the embodiment of the present invention, the brackets 107, vertical embedded parts 108, lifting mechanisms 113, and suspension lines 114 are all arranged on both symmetric sides of the steel column 106.

[0082] Please refer to Figures 18 to 2, To ensure the structural stability of the floor slab at the soil extraction opening 111 and avoid adverse situations such as collapse, in the construction method for in-situ addition of a basement to an existing connected silo provided by the embodiments of the present invention, vertical temporary supports 122 are arranged between the floor slabs of each layer around the soil extraction opening 111 of the basement structure 121. After the floor slab 124 at the soil extraction opening 111 is constructed and reaches the design strength, the vertical temporary supports 122 between the floor slabs of each layer are removed.

[0083] To ensure the construction safety of in-situ addition of a basement to an existing connected silo 100, in the construction method for in-situ addition of a basement to an existing connected silo provided by the embodiments of the present invention, the existing connected silo 100 can be strengthened before demolishing the discharge funnel 104 inside the existing connected silo 100.

[0084] To ensure the safety of the existing connected silo 100 during the lifting process, in the construction method for in-situ addition of a basement to an existing connected silo provided by the embodiments of the present invention, a safety monitoring device is installed on the existing connected silo 100 before demolishing the discharge funnel 104 inside the existing connected silo 100, which is used to monitor the stress and deformation conditions of the existing connected silo to ensure the construction safety of in-situ addition of a basement to the existing connected silo. The safety monitoring device includes a stress sensor for monitoring stress, a displacement sensor and an angle sensor for monitoring deformation. The attitude of the existing connected silo 100 is grasped in real time through the arranged safety monitoring device, and the lifting speed is adjusted in a timely manner according to the results to control the synchronism of the displacements of each monitoring point.

[0085] Please refer to Figures 3 to 4 , In the construction method for in-situ addition of a basement to an existing connected silo provided by the embodiments of the present invention, the existing connected silo 100 is a connected silo, which can solve the construction problems of in-situ addition of a basement below the connected silo 100, so as to achieve the purpose of reusing the underground space of the existing structure. In the construction method for in-situ addition of a basement to an existing connected silo provided by the embodiments of the present invention, the existing connected silo 100 undergoes three force conversions.

[0086] The first force conversion is: after cutting off the connection between the bearing platform foundation 101 and the existing pile foundation 102, the existing connected silo 100 is supported by the steel columns 106 and the newly added pile foundation 123 through the core raft 110. That is to say, the gravity of the existing connected silo 100 is borne by the steel columns 106 and the newly added pile foundation 123 below them.

[0087] The second force conversion is: when the core raft 110 is lifted, the existing connected silo 100 is supported by the lifting system composed of the lifting mechanism 113, the suspension wire 114, the vertical embedded parts 108 and the corbel 107. That is, the gravity of the existing connected silo 100 is borne by the lifting system.

[0088] The third force conversion is as follows: after the lifting mechanism 113, the suspension wire 114, and the vertical embedded part 108 are removed, the existing connected silos 100 are supported by the steel columns 106 and the newly added pile foundation 123 below through the core raft 110. That is, the gravity of the existing connected silos 100 is converted from the lifting system to be borne by the steel columns 106 and the newly added pile foundation 123 below.

[0089] The present invention is not limited to the above specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present invention. Those skilled in the art can make other levels of modifications and changes to the present invention. Thus, if these modifications and changes of the present invention are within the scope of the claims of the present invention, the present invention also intends to include these modifications and changes.

Claims

1. A construction method for in-situ adding a basement to an existing connected silo, characterized in that, Including: Demolish the discharge funnel and floor inside the existing connected silos; Construct a foundation pit retaining structure around the existing connected silos; Construct new pile foundations and steel columns above them inside the foundation pit retaining structure and the existing connected silos; After the foundation pit retaining structure and the new pile foundations reach the design strength, excavate the soil symmetrically inside the foundation pit retaining structure to the elevation of the lower surface of the pile cap foundation of the existing connected silos, exposing the pile cap foundation connected to the existing connected silos; Install corbels on the steel columns below the elevation of the lower surface of the pile cap foundation through bolts; Install vertical embedded parts on the corbels so that the upper ends of the vertical embedded parts are higher than the pile cap foundation; Continue to excavate the soil to expose the lower surface of the corbels and the existing pile foundations below the pile cap foundation. Arrange raft steel bars on the pile cap foundation to extend outside the existing connected silos and pour concrete to connect the pile cap foundation with the concrete to form a core raft on the corbels. A soil extraction hole is reserved on the core raft, and a lifting hole is reserved at the node of the core raft and the steel column. The upper ends of the vertical embedded parts are exposed on the upper surface of the core raft; Install a lifting mechanism at the upper end of the steel column within the coverage of the core raft to be constructed. Connect the lifting mechanism to the vertical embedded parts through a suspension wire. Cut off the connection between the pile cap foundation and the existing pile foundation, remove the bolts connecting the corbels to the steel column, and control the lifting mechanism to lift the core raft and the existing connected silos thereon upward along the steel column through the suspension wire, its connected vertical embedded parts and corbels through the lifting hole. After the core raft is lifted to the specified height, connect the corbels to the steel column through bolts; Construct an outer raft of reinforced concrete structure between the core raft and the foundation pit retaining structure, and seal the lifting holes on the core raft so that the outer raft and the core raft form a basement roof with a soil extraction hole; After the basement roof reaches the design strength, remove the lifting mechanism and cut off the steel column above the basement roof; Install a track-type soil extraction device at the position of the soil extraction hole in the existing connected silos. The track-type soil extraction device includes a conveyor belt that straddles the soil extraction hole on the same straight line and extends outside the existing connected silos on the basement roof, a track beam that is perpendicular to the conveyor belt and straddles the soil extraction hole above the conveyor belt, and a soil transport box that moves horizontally along the length direction of the track beam and moves up and down relative to the track beam; Continue to excavate the soil downward and load it into the soil transport box. After the loaded soil transport box is lifted upward along the soil extraction hole, it moves horizontally relative to the track beam to transport the soil transport box or the soil therein out of the existing connected silos through the conveyor belt, and construct the basement structure; After the basement structure reaches the designed number of floors, supplement and construct the new pile foundations and the steel columns above them at the soil extraction hole in the basement structure through the soil extraction hole, and seal the soil extraction hole on the floor of the basement structure with the soil extraction hole by a closed floor of reinforced concrete structure to form a complete floor; 2. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, Except for the steel columns at the outermost periphery of the foundation pit retaining structure, the upper ends of the remaining steel columns are at the same elevation plane, and the upper ends of the outermost steel columns are lower than the upper ends of the remaining steel columns; 3. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, The upper ends of all the vertical embedded parts are at the same elevation plane.

4. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, Before cutting off the connection between the bearing platform foundation and the existing pile foundation, the core raft is pre-lifted by a lifting mechanism, and the core raft is pre-tightened by the lifting mechanism.

5. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, The lifting mechanism includes a motor and the suspension line.

6. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, The corbels, vertical embedded parts, lifting mechanism and suspension line are all arranged on both symmetrical sides of the steel column.

7. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, Vertical temporary supports are arranged between the floors around the soil excavation opening of the basement structure. After the floor slab at the soil excavation opening is constructed and reaches the design strength, the vertical temporary supports between the floors are removed.

8. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, The existing connected silo is strengthened before demolishing the discharge funnel inside the existing connected silo.

9. The construction method for in-situ adding a basement to an existing connected silo according to claim 1, characterized in that, Before demolishing the discharge funnel inside the existing connected silo, a safety monitoring device is installed on the existing connected silo to monitor the stress and deformation conditions of the existing connected silo to ensure the construction safety of in-situ adding a basement to the existing connected silo.

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