Installation method of ultra-deep segmented large-diameter working well sinking system

Abstract

The application discloses an installation method of an ultra-deep segmental large-diameter working well pressure sinking system and relates to the technical field of working well construction. The application comprises the following steps: step one, soil body reinforcement; step two, excavation of a sinking well foundation pit; step three, excavation of a pressure body foundation pit; step four, construction of a pressure body in the pressure body foundation pit; step five, installation of a counterforce frame; step six, pressure sinking; step seven, removal of the counterforce frame; and step eight, removal of the pressure body. The application provides controllable thrust to the sinking well body, so that the sinking well can sink faster and be more controllable, and the sinking well can be made in small segments, which is more advantageous in safety risk control. The counterforce device is provided with ballast weight by means of the peripheral weight distribution platform, and the sinking well is provided with a 'hoop' effect, the peripheral weight distribution platform is made of a ground anchor steel pipe and a prefabricated and cast-in-situ combined concrete structure weight, the construction process is simple, and the construction quality is easier to control.

Description

Technical Field

[0001] This invention relates to the field of working well sinking construction technology, and is applicable to the construction of ultra-deep segmental large-diameter working well sinking systems in municipal, water conservancy and other engineering projects. Background Technology

[0002] Currently, caisson construction commonly relies on the caisson's own weight in conjunction with excavation. This method requires sufficient structural weight, results in slow construction progress, frequently encounters sinking difficulties, and is prone to quality problems such as caisson tilting. In contrast, the forced-in shaft excavation method, with its advantages of deep burial depth, high overall rigidity, and strong bearing capacity, is better suited to these requirements in many situations, thus possessing irreplaceable competitiveness and broad application prospects in underground engineering construction. However, as the size and burial depth of forced-in shafts gradually increase, traditional excavation methods, when applied to soft cohesive soil layers, face extreme risks such as shaft stalling, tilting, displacement, sudden sinking, or oversinking due to the high cohesion and frictional resistance of the soil. This leads to significant disturbance to the surrounding soil layers, thus restricting the further promotion and application of this type of excavation method. Summary of the Invention

[0003] In view of the above-mentioned deficiencies in the prior art, the purpose of this invention is to provide an installation method for an ultra-deep segmental large-diameter working well sinking system.

[0004] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0005] A method for installing an ultra-deep segmental large-diameter working well settling system, characterized by the following steps:

[0006] Step 1: Soil reinforcement: Reinforce the soil at the junction of the jacking pipe and the caisson to be constructed, and within the jacking pipe opening area. When reinforcing the soil, rely on the outer boundary line of the caisson to construct the jet grouting pile reinforcement area, the triaxial mixing pile reinforcement area, and the cement mixing pile water-stop curtain in sequence within the original soil. The upper end of the cement mixing pile water-stop curtain extends to the ground surface.

[0007] Step 2: Excavate the caisson foundation pit: Excavate the caisson foundation pit in the designated caisson area;

[0008] Step 3: Excavate the foundation pit for the counterweight body: Excavate the foundation pit for the counterweight body along the outer side of the upper end of the caisson to be constructed;

[0009] Step 4: Construct counterweights within the counterweight foundation pit;

[0010] Step 5: Install the reaction frame: The reaction frame includes a load-bearing beam lying horizontally on the ballast body, and a column perpendicular to the load-bearing beam and located on the inner edge of the ballast body. Diagonal braces and stiffening ribs are provided between the load-bearing beam and the column. A crossbeam is set on the top of the column, and a jack is installed on the crossbeam.

[0011] The reaction frames are evenly distributed and installed on the upper end of the counterweight;

[0012] Step Six: Pressure Sinking: Cast-in-place caisson segments in the caisson foundation pit. After the caisson segments are cast and cured, apply sinking pressure to the top of the caisson segments using jacks to complete the sinking of the current caisson segment. After the current caisson segment is cast and sinked, the next caisson segment is cast and sinked in the same way at the top of the current caisson segment. Through the casting and sinking of several caisson segments, the construction of the entire caisson is completed.

[0013] Step 7: Dismantle the reaction frame;

[0014] Step 8: Remove the counterweight.

[0015] As a preferred option, the specific construction method for the counterweight in step four includes:

[0016] S1. Prefabricated blocks for filling counterweights are pre-processed at the factory or on-site.

[0017] S2. Construction of the bottom and surrounding frame structure of the ballast body: The bottom slab of the ballast body is cast in place at the bottom of the ballast body foundation pit, and then the inner and outer ring walls of the ballast body are cast in place along the side walls of the ballast body foundation pit respectively.

[0018] S3. Construction counterweight filling structure: Precast blocks are installed in the filling space formed by the bottom slab, inner ring wall and outer ring wall;

[0019] S4. Construction of steel pipe piles: Steel pipe piles for installing reaction frames are driven into the precast blocks of the counterweight body. Anchor bars are inserted into the steel pipe piles, and fine sand is filled into the steel pipe piles.

[0020] S5. Top slab for constructing counterweight: A top slab is cast in place on top of the precast blocks. The top slab, bottom slab, inner ring wall, outer ring wall and precast blocks form a complete counterweight; the upper end of the anchor bar is higher than the top slab.

[0021] As a preferred embodiment, in step five, a stabilizing beam perpendicular to the load-bearing beam is provided on the load-bearing beam, and wing beams parallel to the load-bearing beam are provided at both ends of the stabilizing beam. The wing beams on the reaction frame are fixedly connected to the anchor bars on the steel pipe piles by bolts, and each wing beam is connected to the two steel pipe piles below.

[0022] Preferably, the bottom of the column has a counterbalance beam perpendicular to it; the load-bearing beam, counterbalance beam, stabilizing beam, and wing beam are all installed in contact with the top plate.

[0023] Preferably, the precast blocks are provided with lifting lugs and reserved holes for inserting steel pipe piles.

[0024] As a preferred option, in step eight, when removing the counterweight, first chisel off the top plate of the counterweight and lift the precast blocks away in sequence, and then chisel off the inner ring wall, outer ring wall, and bottom plate of the counterweight.

[0025] The embodiments of the present invention have the following beneficial effects:

[0026] (1) By providing additional controllable thrust to the well body during the construction of the caisson, the construction of the caisson can be faster and more efficient, and the caisson no longer needs to sink by gravity, thereby reducing the structural weight of the well body, saving costs and materials; and can speed up the construction speed, control the attitude of the caisson, and have obvious correction effect, overcoming difficult geological conditions.

[0027] (2) By pressurizing equipment, a soil plug is formed at the bottom of the well, and the sealing effect at the bottom of the caisson is obvious, preventing soil from outside the well from flowing into the well and reducing the settlement of the soil outside the well and surrounding structures.

[0028] (3) The counterweight platform around the well provides sufficient ballast weight for the reaction device to press down the caisson. Secondly, it acts as a "clamp" for the caisson, which can fundamentally prevent the caisson from swinging during the sinking process, reduce the disturbance to the surrounding soil, and effectively ensure the verticality of the caisson during the sinking process, preventing the caisson from tilting or rotating.

[0029] (4) Using ground anchor steel pipe + precast and cast-in-place combined concrete structure counterweight as well perimeter sinking bearing platform can minimize the amount of concrete to be removed while ensuring the integrity of the counterweight. If large volume concrete is used for all cast-in-place construction, the overall casting construction process is complicated, the safety risk is high, the quality is difficult to control, the concrete removal is difficult in the later stage, the construction period is long, and the demolition cost is high.

[0030] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0031] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a cross-sectional view of the caisson construction of the present invention;

[0033] Figure 2 for Figure 1 Cross-sectional view of the central well circumferential pressure body;

[0034] Figure 3 A 3D diagram of the reaction frame;

[0035] Figure 4 Top view of the reaction frame installation;

[0036] Figure 5 This is a top view of the counterweight.

[0037] Figure 6 This is a cross-sectional view of the precast block;

[0038] Figure 7 A top view of the soil reinforcement in the caisson construction area.

[0039] The attached diagram lists the components represented by each number as follows:

[0040] 1-Pipe jacking; 2-Caison; 3-Original soil; 4-Triaxial mixing pile reinforcement zone; 5-Jet jet grouting pile reinforcement zone; 6-Cement mixing pile water-stop curtain; 7-Pipe jacking opening; 8-Outer ring wall; 9-Inner ring wall; 10-Base slab; 11-Top slab; 12-Precast block; 13-Steel pipe pile; 14-Anchor bar; 15-Fine sand; 16-Reaction frame; 17-Bolt; 18-Bearing beam; 19-Column; 20-Diagonal brace; 21-Stiffening rib plate; 22-Crossbeam; 23-Jack; 24-Reserved hole; 25-Lifting lug; 26-Stabilizing beam; 27-Wing beam; 28-Balancing beam; 29-Counterweight. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] To keep the following description of the embodiments of the present invention clear and concise, detailed descriptions of known functions and known components are omitted.

[0043] Please see Figure 1-7 As shown in the figure, this embodiment provides a construction method for an ultra-deep segmental large-diameter working well sinking system, including the following steps:

[0044] Step 1: Soil reinforcement: Reinforce the soil at the junction of the jacking pipe 1 and the caisson 2 to be constructed, and within the range of the jacking pipe opening 7. During soil reinforcement, relying on the outer boundary line of the caisson 2, sequentially construct the jet grouting pile reinforcement zone 5, the triaxial mixing pile reinforcement zone 4, and the cement mixing pile water-stop curtain 6 within the undisturbed soil 3. The upper end of the cement mixing pile water-stop curtain 6 extends to the ground surface. The triaxial mixing pile reinforcement zone 4 is located outside the jet grouting pile reinforcement zone 5, and the cement mixing pile water-stop curtain 6 is located outside the triaxial mixing pile reinforcement zone 4.

[0045] Step 2: Excavate the caisson foundation pit: Excavate the caisson foundation pit in the designated caisson area.

[0046] Step 3: Excavate the foundation pit for the counterweight body: Excavate the foundation pit for the counterweight body along the outer side of the upper end of the caisson 2 to be constructed, with the foundation pit matching the structural dimensions of the counterweight body 29.

[0047] Step 4: Construct counterweight 29 within the foundation pit. Counterweight 29 serves as the counterweight structure for the sinking jack 23. Specific construction methods include:

[0048] S1. Prefabricated blocks 12 for filling the counterweight 29 are prefabricated at the factory or on site.

[0049] S2. Construction of the bottom and surrounding frame structure of the ballast body 29: The bottom slab 10 of the ballast body 29 is cast in place at the bottom of the foundation pit of the ballast body 29, and then the inner ring wall 9 and the outer ring wall 8 of the ballast body 29 are cast in place along the side wall of the foundation pit of the ballast body.

[0050] S3, Construction counterweight 29 filling structure: Precast blocks 12 are installed in the filling space formed by the base plate 10, inner ring wall 9 and outer ring wall 8.

[0051] S4. Construction of steel pipe piles 13: Steel pipe piles 13 for installing reaction frames 16 are driven into the precast blocks 12 of the counterweight body 29. Anchor bars 14 are inserted into the steel pipe piles 13, and fine sand 15 is filled into the steel pipe piles 13.

[0052] S5. Construction of the top slab 11 of the counterweight body 29: The top slab 11 is cast in place on the top of the precast block 12. The top slab 11, the bottom slab 10, the inner ring wall 9, the outer ring wall 8 and the precast block 12 form a complete counterweight body 29, thereby completing the construction of the entire counterweight body 29; the upper end of the anchor bar 14 is higher than the top slab 11.

[0053] Among them, the counterweight 29 is a ring-shaped concrete structure surrounding the caisson 2.

[0054] The counterweight 29 is composed of a cast-in-place frame and precast blocks 12. The cast-in-place frame includes a base slab 10, an inner ring wall 9, an outer ring wall 8, and a top slab 11. The base slab 10, the inner ring wall 9, and the outer ring wall 8 form a filling space for filling the precast blocks 12. The filling space is filled with several precast blocks 12, and the several precast blocks 12 are assembled into a ring-shaped concrete filler with the same size as the filling space.

[0055] The precast block 12 is provided with lifting lugs 25 for hoisting, and the precast block 12 is provided with reserved holes 24 for inserting steel pipe piles 13. The diameter of the reserved holes 24 matches the outer diameter of the steel pipe piles 13 to install the steel pipe piles 13.

[0056] The steel pipe pile 13 is composed of an outer steel pipe, anchor bars 14 and fine sand 15, with the fine sand 15 filling the space between the steel pipe and the anchor bars 14.

[0057] The steel pipe piles 13 are used in conjunction with the reaction frame 16. Each reaction frame 16 corresponds to a set of steel pipe piles 13, and a set includes four steel pipe piles 13. The steel pipe piles 13 can directly bear the pressure of the reaction frame 16.

[0058] Step 5: Install reaction frame 16: The reaction frame 16 includes a load-bearing beam 18 lying horizontally on the counterweight 29, and a column 19 perpendicular to the load-bearing beam 18 and located on the inner edge of the counterweight 29. Diagonal bracing 20 and stiffening ribs 21 are provided between the load-bearing beam 18 and the column 19. A crossbeam 22 is provided on the top of the column 19, and a jack 23 is installed on the crossbeam 22. The jack 23 is vertically positioned below the crossbeam 22.

[0059] The reaction frames 16 are evenly distributed on the upper end of the counterweight 29, and the reaction frames 16 are arranged in a circular array on the upper end of the counterweight 29; the jacks 23 on the reaction frames 16 apply sinking pressure to the caisson 2, and the reaction frames 16 transmit the pressure of the jacks 23 to the counterweight 29.

[0060] Among them, the load-bearing beam 18 is provided with a stabilizing beam 26 perpendicular to it. At both ends of the stabilizing beam 26, there are wing beams 27 parallel to the load-bearing beam 18. The wing beams 27 on the reaction frame 16 are fixedly connected to the anchor bars 14 on the steel pipe piles 13 by bolts 17. Each wing beam 27 is connected to the two steel pipe piles 13 below.

[0061] The bottom of the column 19 has a vertical balance beam 28; the load-bearing beam 18, balance beam 28, stabilizing beam 26, and wing beam 27 are all installed in contact with the top plate 11.

[0062] Step Six: Pressure Sinking: Cast the caisson segments in the caisson foundation pit. After the caisson segments are cast and cured, apply sinking pressure to the top of the caisson segments using jacks 23 to complete the sinking of the current caisson segment. After the current caisson segment is cast and sinked, cast and sink the next caisson segment in the same way at the top of the current caisson segment. Through the casting and sinking of several caisson segments, the construction of the entire caisson 2 is completed.

[0063] Step 7: Remove the reaction frame 16.

[0064] Step 8: Remove the ballast body 29. After the construction of the caisson 2 is completed, first remove the top plate 11 of the ballast body 29, and then lift the precast blocks 12 in sequence. Then remove the inner ring wall 9, outer ring wall 8, and bottom plate 10 of the ballast body 29.

Claims

1. A method for installing an ultra-deep segmental large-diameter working well settling system, characterized in that, Includes the following steps: Step 1, Soil reinforcement: Reinforce the soil at the junction of the jacking pipe (1) and the caisson (2) to be constructed, and within the range of the jacking pipe opening (7). When reinforcing the soil, rely on the outer boundary line of the caisson (2) to construct the jet grouting pile reinforcement area (5), the three-axis mixing pile reinforcement area (4), and the cement mixing pile water-stop curtain (6) in sequence within the original soil (3). The upper end of the cement mixing pile water-stop curtain (6) extends to the ground surface. Step 2: Excavate the caisson foundation pit: Excavate the caisson foundation pit in the designated caisson area; Step 3: Excavate the foundation pit for the counterweight body: Excavate the foundation pit for the counterweight body along the outer side of the upper end of the caisson (2) to be constructed; Step 4: Construct the counterweight (29) within the counterweight foundation pit; the specific construction method for the counterweight (29) includes: S1. Prefabricated blocks (12) for filling the ballast body (29) are prefabricated in the factory or on site; S2. Construction of the bottom and surrounding frame structure of the ballast body (29): The bottom slab (10) of the ballast body (29) is cast in place at the bottom of the ballast body foundation pit, and then the inner ring wall (9) and outer ring wall (8) of the ballast body (29) are cast in place along the side wall of the ballast body foundation pit respectively. S3, Construction counterweight (29) filling structure: Precast blocks (12) are installed in the filling space formed by the bottom plate (10), inner ring wall (9) and outer ring wall (8); S4. Construction of steel pipe piles (13): Steel pipe piles (13) for installing reaction frames (16) are driven into the precast blocks (12) of the counterweight body (29). Anchor bars (14) are inserted into the steel pipe piles (13), and fine sand (15) is filled into the steel pipe piles (13). S5. Top slab (11) for constructing counterweight (29): Top slab (11) is cast in place on top of precast block (12). Top slab (11), bottom slab (10), inner ring wall (9), outer ring wall (8) and precast block (12) form a complete counterweight (29); the upper end of anchor bar (14) is higher than top slab (11); Step 5, Install the reaction frame (16): The reaction frame (16) includes a load-bearing beam (18) lying horizontally on the counterweight (29), and a column (19) perpendicular to the load-bearing beam (18) and located on the inner edge of the counterweight (29). A diagonal brace (20) and a stiffening rib plate (21) are provided between the load-bearing beam (18) and the column (19). A crossbeam (22) is provided at the top of the column (19), and a jack (23) is installed on the crossbeam (22). The reaction frame (16) is evenly distributed and installed on the upper end of the counterweight (29); Step 6, Pressure Sinking: Cast the caisson segments in the caisson foundation pit. After the caisson segments are cast and cured, apply sinking pressure to the top of the caisson segments using jacks (23) to complete the sinking of the current caisson segment. After the current caisson segment is cast and sinked, cast and sink the next caisson segment in the same way at the top of the current caisson segment. Through the casting and sinking of several caisson segments, the construction of the entire caisson (2) is completed. Step 7: Remove the reaction frame (16); Step 8: Remove the counterweight (29).

2. The installation method of the ultra-deep segmental large-diameter working well sinking system according to claim 1, characterized in that, In step five, a stabilizing beam (26) perpendicular to the load-bearing beam (18) is provided on the load-bearing beam (18). At both ends of the stabilizing beam (26), there are wing beams (27) parallel to the load-bearing beam (18). The wing beams (27) on the reaction frame (16) are fixedly connected to the anchor bars (14) on the steel pipe piles (13) by bolts (17). Each wing beam (27) is connected to the two steel pipe piles (13) below.

3. The installation method of the ultra-deep segmental large-diameter working well sinking system according to claim 2, characterized in that, The bottom of the column (19) has a balance beam (28) perpendicular to it; the load-bearing beam (18), balance beam (28), stabilizing beam (26), and wing beam (27) are all installed in contact with the top plate (11).

4. The installation method of the ultra-deep segmental large-diameter working well sinking system according to claim 1, characterized in that, The precast block (12) is provided with lifting lugs (25) and reserved holes (24) for inserting steel pipe piles (13).

5. The installation method of the ultra-deep segmental large-diameter working well sinking system according to claim 1, characterized in that, In step eight, when removing the ballast body (29), first chisel off the top plate (11) of the ballast body (29), and then lift off the precast blocks (12) in sequence. Then chisel off the inner ring wall (9), outer ring wall (8), and bottom plate (10) of the ballast body (29).

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