Double-layer steel open caisson structure and press-in type construction method and system thereof

Abstract

The invention discloses a double-layer steel open caisson structure and a press-in type construction method and system thereof. The construction method comprises the steps of construction of an anti-pulling pile subsystem, arrangement of a double-layer steel cylinder body and a counter-force press-sinking subsystem, press-sinking construction of the double-layer steel cylinder body, section steel insertion and construction of improved soil between well walls. The method has the advantages of being fast in soil breaking, small in soil squeezing effect, high in pressing and sinking efficiency and small in disturbance to the surrounding environment, the structural rigidity of the well wall is improved, the bearing capacity of water and soil pressure loads on the well wall side is improved, and the problem that construction safety is affected due to large structural deformation is solved.

Description

Technical Field

[0001] This invention relates to the field of building construction technology, and in particular to a double-layer steel caisson structure and its press-in construction method and system. Background Technology

[0002] In construction, with the deepening of urbanization and the in-depth development of infrastructure, more and more projects need to address the challenges of developing complex deep underground spaces. These projects often face demanding conditions such as large excavation depths, complex geological conditions, and high requirements for controlling disturbances to the surrounding environment. Traditional caisson construction technology is gradually revealing its limitations in the face of these challenges, including limited sinking depth, insufficient structural stiffness, and significant environmental impact. In the construction technology of large-diameter, deep steel cylinder caissons, as the caisson diameter increases, the circumferential stiffness of the steel cylinder decreases significantly; when the caisson depth increases, the water and soil pressure load on the caisson sidewalls also increases significantly. When both the excavation depth and diameter increase simultaneously, the conventional single-layer large-diameter steel cylinder used as the caisson wall is prone to local instability and buckling, adversely affecting the structural stress of the caisson wall, easily causing structural deformation, and affecting the construction safety of the caisson structure. To reduce structural deformation, thick-walled concrete cylindrical structures or double-layered closed steel cylinders are used as well walls in this field. However, during the construction of caissons, the large thickness of the well walls leads to a large soil squeezing effect, resulting in difficulties in sinking and significant disturbance to the surrounding environment. Summary of the Invention

[0003] The purpose of this invention is to provide a double-layer steel caisson structure and its pressurized construction method and system to solve the problem of excessive structural deformation affecting construction safety caused by the thin wall thickness and insufficient structural rigidity and stability of a single-layer large-diameter steel cylinder as the caisson wall. It also solves the problem of difficulty in sinking and large disturbance to the surrounding environment caused by the large soil squeezing effect due to the large wall thickness of thick-walled concrete cylinder or double-layer closed steel cylinder as the caisson wall.

[0004] To address the aforementioned technical problems, this invention provides a method for the forced-in construction of a double-layer steel caisson structure, comprising:

[0005] Multiple circumferentially evenly arranged anti-tension piles are constructed in the soil between the walls of the double-layer steel caisson structure within the annular gap between the layers at the construction location, forming an anti-tension pile subsystem.

[0006] Anchor plates and their connected steel strands are anchored inside each tension pile. The steel strands are extended upwards beyond the ground at the construction location. Double-layered steel cylinders with locking mechanisms are arranged in sections as double-layered well walls at the construction location, aligning the annular gaps between the layers of the double-layered steel cylinders with each tension pile. The steel strands are passed through the annular gaps between the layers and out of the double-layered steel cylinders. At the top of the double-layered steel cylinders, a sinking beam, a through-hole jack, and an anchor are sequentially installed upwards, so that the anchor plates, steel strands, sinking beam, through-hole jack, and anchor form a reaction sinking subsystem to provide downward pressure to the double-layered steel cylinders. The through-hole jack is controlled to repeatedly extend and retract, driving the steel strands to apply downward reaction force to the double-layered steel cylinders through the sinking beam and locking them with the anchor. This allows the double-layered steel cylinders with locking mechanisms, with tension piles embedded within them, to be synchronously and progressively sinked to the design depth within the soil.

[0007] Insert the steel profile into the soil between the layers of the well wall along each locking position of the double-layer steel cylinder, so that the double-layer steel cylinder with locking and the steel profile form a double-layer non-enclosed steel well wall subsystem.

[0008] The soil between the well walls in the interlayer annular gap is reinforced by the MJS reinforcement process to form improved soil between the well walls, thus completing the construction of the double-layer steel caisson structure.

[0009] Furthermore, the method for constructing a double-layer steel caisson structure using a press-fit method provided by the present invention also includes:

[0010] After the improved soil between the well walls reaches the design strength, the soil inside the pit in the inner well wall is excavated, and concrete is poured to seal the bottom.

[0011] Furthermore, the method for constructing a double-layer steel caisson structure using a press-fit method provided by the present invention also includes:

[0012] Remove the anchorages, through-hole jacks, and sinking beams, and cut the steel strands above ground.

[0013] Furthermore, in the press-in construction method for the double-layer steel caisson structure provided by the present invention, the anti-uplift piles are four in number, and the pile positions are arranged in a biaxial symmetrical manner, with the pile positions relative to the X-axis at angles of 30°, 150°, 210°, and 330°.

[0014] Furthermore, in the press-in construction method of the double-layer steel caisson structure provided by the present invention, the steel profile consists of six steel sections arranged in a ring array within the annular gap between the layers of the double-layer steel cylinder.

[0015] Furthermore, in the pressing construction method of the double-layer steel caisson structure provided by the present invention, the steel section is an I-beam or an H-beam, the plane of the web of the steel section is aligned with the center, and the plane of the flange of the steel section is parallel to the circumferential tangent of the double-layer steel cylinder.

[0016] Furthermore, in the pressing construction method of the double-layer steel caisson structure provided by the present invention, the anchorage length of the steel strand in the anti-uplift pile is not less than 50d and not less than 1000mm, where d is the diameter of the steel strand.

[0017] Furthermore, in the press-in construction method for the double-layer steel caisson structure provided by the present invention, the locking buckle is composed of four rectangularly distributed opening components. The opening components are arranged in pairs on the inner wall of the outer steel cylinder and the outer wall of the inner steel cylinder. The pair of opening components arranged on the inner wall of the outer steel cylinder are aligned with the outer edges of the two corners of one flange of the steel section, and the pair of opening components arranged on the outer wall of the inner steel cylinder are aligned with the outer edges of the two corners of the other flange of the steel section.

[0018] To address the aforementioned technical problems, the present invention also provides a forced-in construction system for a double-layer steel caisson structure, comprising:

[0019] A double-layer non-enclosed steel well wall subsystem includes a double-layer steel cylinder with locking buckles and multiple steel profiles evenly arranged circumferentially within the annular gap between the inner and outer steel cylinders, with each steel profile correspondingly inserted into one of the locking buckles;

[0020] The tension pile system consists of multiple piles, evenly distributed circumferentially within the soil in the annular gap between the layers of a double-layer steel cylinder, with the tension piles and the steel sections being staggered.

[0021] The reaction pressure sinking subsystem is used to press the double-layer steel cylinder into the soil for caisson construction. It includes an anchor plate anchored in the anti-tension pile and its connected steel strand. The steel strand extends upward out of the double-layer steel cylinder and passes through the steel strand. The sinking crossbeam, the through jack and the anchor are set at the top of the double-layer steel cylinder in sequence.

[0022] The soil reinforcement subsystem uses the MJS reinforcement process to reinforce the soil within the interlayer annular gaps, forming improved soil between the well walls.

[0023] To address the aforementioned technical problems, the present invention also provides a double-layer steel caisson structure, comprising:

[0024] The double-layer non-enclosed steel well wall includes a double-layer steel cylinder with locking buckles that extends into the soil and multiple steel sections evenly arranged in the annular gap between the layers, with each steel section being inserted into one of the locking buckles.

[0025] The tension piles are multiple piles, evenly distributed circumferentially, installed in the soil within the annular gap between the layers of a double-layered steel cylinder. The tension piles are staggered from the steel sections.

[0026] The improved soil between well walls is formed by reinforcing the soil in the annular gap between layers using the MJS reinforcement process.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The double-layer steel caisson structure and its pressing construction method and system provided by this invention, on the one hand, adopt a double-layer non-enclosed steel caisson wall composed of a thin-walled double-layer steel cylinder and steel sections inserted into the interlayer annular gap. The inner and outer steel cylinders are simultaneously pressed into the soil by a reaction force pressing subsystem formed by anchor plates, steel strands, pressing beams, through-hole jacks and anchors. Compared with traditional thick-walled concrete cylinders and thick-walled double-layer enclosed steel cylinders, it has the advantages of fast soil breaking, small soil squeezing effect, high pressing efficiency, and minimal disturbance to the surrounding environment. It avoids the problems of large soil squeezing effect and difficulty in sinking and large disturbance to the surrounding environment caused by using thick-walled concrete cylinders or double-layer enclosed steel cylinders as thick caisson walls. On the other hand, by inserting the steel sections into the soil within the interlayer annular gap through the locking points of the double-layer steel cylinder, and by improving the soil between the well walls using the MJS reinforcement process, a composite double-layer steel caisson structure is formed, consisting of the double-layer steel cylinder and the anti-uplift piles, steel sections, and improved soil between the well walls. This improves the structural stiffness of the well walls and the bearing capacity of the water and soil pressure loads on the sides of the well walls. It avoids the problem of insufficient load bearing capacity on the sides of the well walls, resulting in excessive structural deformation and affecting construction safety, which is caused by using a single-layer large-diameter steel cylinder as a thin well wall.

[0029] The double-layer steel caisson structure and its press-in construction method and system provided by this invention enable the simultaneous pressing and sinking of the double-layer steel cylinder into the soil through a reaction-force pressing subsystem. This achieves press-in caisson construction, rather than relying on the gravity sinking of the double-layer steel cylinder, thus improving the construction efficiency and stability of the double-layer steel cylinder caisson. The reaction-force pressing subsystem consists of anchor plates anchored within tension piles and their connected steel strands, as well as a pressing beam, a through-hole jack, and anchorages sequentially arranged upwards at the top of the double-layer steel cylinder, passing through the steel strands. It has the advantages of simple structure, good stability, and low cost. The anchor plates are anchored within the tension piles, further enhancing the stability of the reaction-force pressing subsystem. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the planar structure of the anti-uplift piles and the double-layer steel cylinder;

[0031] Figure 2 It is a schematic diagram of the elevation structure of the construction anti-uplift piles, the double-layer steel caisson structure, and the reaction pressure sinker system;

[0032] Figure 3 This is a schematic diagram of the planar structure in which the installation steel is inserted at the locking point of the double-layer steel caisson structure;

[0033] Figure 4 It is an enlarged view of the insertion and installation of the latch and the steel section joint;

[0034] Figure 5 This is a schematic diagram of the planar structure of the improved soil between the construction well walls;

[0035] Figure 6 It is a schematic diagram of the elevation structure for removing anchors, through jacks and sinking beams, cutting steel strands and excavating soil in the pit to construct bottom sealing concrete. Figure 7 This is a flowchart of the press-in construction method for a double-layer steel caisson structure;

[0036] As shown in the figure:

[0037] 101. Soil between well walls; 102. Anti-tension pile; 103. Anchor plate; 104. Steel strand; 105. Ground surface; 106. Lock; 106a. Opening component; 107. Inner steel cylinder; 108. Outer steel cylinder; 109. Sinking beam; 110. Through-hole jack; 111. Anchor; 112. Structural steel; 113. Improved soil between well walls; 114. Soil inside the pit; 115. Bottom sealing concrete. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the present invention.

[0039] Please refer to Figures 4 to 6 This invention provides a double-layer steel caisson structure, comprising:

[0040] The double-layer non-enclosed steel well wall includes a double-layer steel cylinder with a locking buckle 106 extending into the soil and multiple steel sections 112 evenly arranged in the annular gap between the layers, with each steel section 112 being inserted into one of the locking buckles 106.

[0041] The tension piles 102 are multiple piles, evenly distributed circumferentially within the soil in the annular gap between the layers of the double-layer steel cylinder. The tension piles 102 are staggered from the steel section 112.

[0042] The improved soil 113 between the well walls is formed by reinforcing the soil in the annular gap between the layers using the MJS reinforcement process.

[0043] Please refer to Figures 1 to 7 This invention provides a method for the forced-in construction of a double-layer steel caisson structure, comprising:

[0044] Step S1, Construction of the anti-tension pile subsystem: Multiple anti-tension piles 102 are constructed within the soil 101 between the layers of the annular gap in the double-layer steel caisson structure to be constructed, forming an anti-tension pile subsystem. The diameter of the anti-tension piles 102 is less than or equal to the width of the annular gap between the layers, and the verticality of the anti-tension piles is controlled to be less than 1 / 500.

[0045] Step S2: Arrangement of the double-layer steel cylinder and reaction pressure sinking subsystem, and construction of the double-layer steel cylinder pressure sinking: Anchor plates 103 and their connected steel strands 104 are anchored inside each tension pile 102. The steel strands 104 are extended upwards out of the ground 105 at the construction location. The double-layer steel cylinder with locking buckles 106 is arranged in sections as a double-layer well wall at the construction location, so that the annular gap between the layers of the double-layer steel cylinder is aligned with each tension pile 102. The steel strands 104 are passed through the annular gap between the layers and out of the double-layer steel cylinder. At the top of the double-layer steel cylinder, anchor plates 103 and their connected steel strands 104 are installed upwards in sequence. A sinking beam 109, a through-hole jack 110, and an anchor 111 are installed through the steel strand 104, forming a reaction force sinking subsystem that provides downward pressure to the double-layer steel cylinder. The anchor plate 103, steel strand 104, sinking beam 109, through-hole jack 110, and anchor 111 together create this system. The through-hole jack 110 is repeatedly extended and retracted, causing the steel strand 104 to apply downward reaction force to the double-layer steel cylinder through the sinking beam 109 and lock in place with the anchor 111. This allows the double-layer steel cylinder with locking buckles 106, fitted with tension piles 102, to be synchronously and progressively sinked to the designed depth within the soil. During sinking, the sinking rate is controlled to not exceed 5 cm / min, and the load is applied in stages of 25%, 50%, 75%, and 100% of the theoretical downward pressure. The verticality deviation should not exceed 1 / 500, and the pressure difference between each 110-ton jack should be controlled within 5t to ensure the caisson is pressed down smoothly, thereby improving the construction quality of the caisson.

[0046] The double-layer steel cylinder consists of an inner steel cylinder 107 and an outer steel cylinder 108. The inner diameter of the inner steel cylinder 107 is D1, and the inner diameter of the outer steel cylinder 108 is D2. The wall thickness t of both the inner and outer steel cylinders is the same, which can be 28mm-36mm. The width of the annular gap between the inner and outer steel cylinders is b = D2-D1, where b ∈ (0.8~1.2)m. The height h0 of a single section of the inner and outer steel cylinders is 3m-4m. The above-mentioned dimensional parameters of the double-layer steel cylinder are only preferred embodiments and are not limited thereto. In this case, the length of the transverse pressure beam 109 can be 2m-2.5m, but is not limited thereto; it must at least be greater than the width of the annular gap between the inner and outer steel cylinders.

[0047] Step S3, steel section insertion: Insert the steel section 112 into the soil 101 between the layers of the well wall and the interlayer annular gap along the positions of the locking buckles 106 of the double-layer steel cylinder, so that the double-layer steel cylinder with locking buckles and the steel section 112 form a double-layer non-enclosed steel well wall subsystem. The steel section 112 is positioned and locked by the locking buckles 106.

[0048] A steel section 112 is inserted and installed at one of the locking buckles 106. A reserved gap δ can be provided between the flange plate of the steel section 112 and the inner and outer steel cylinders, where the reserved gap δ can be 10mm-20mm. The specifications of the steel section 112 are determined by the width of the interlayer annular gap. The cross-sectional height H of the steel section 112 is ≤ b-2δ. The thickness of the web and flange plates of the steel section 112 can be consistent with the thickness t of the inner and outer steel cylinders. The cross-sectional width W of the steel section 112 is 15ε. k· t, where ε k For the coefficient, the material of the steel section 112 is Q235 or Q345. There can be six steel sections 112, arranged in a ring array within the soil 101 between the layers of the double-layer steel cylinder. These six or more steel sections 112 evenly bear the water and soil pressure load, improving the structural strength of the interlayer annular gap of the double-layer steel cylinder. To further improve the structural strength of the interlayer annular gap of the double-layer steel cylinder, the steel section 112 is an I-beam or H-beam 112, with the web plane of the steel section 112 aligned with the center, and the flange plane of the steel section 112 parallel to the circumferential tangent of the double-layer steel cylinder. Thus, the two parallel flanges of the steel section 112 bear the load of water and soil pressure on the inner side of the inner steel cylinder 107 and the outer side of the outer steel cylinder 108, and are supported by the web of the steel section 112, thereby improving the structural strength of the interlayer annular gap of the double-layer steel cylinder and reducing or avoiding structural deformation caused by the interlayer annular gap of the double-layer steel cylinder.

[0049] The locking buckle 106 can be composed of four rectangularly distributed opening components 106a. These opening components 106a are arranged in pairs, welded or bolted together, on the inner wall of the outer steel cylinder 108 and the outer wall of the inner steel cylinder 107. One pair of opening components 106a on the inner wall of the outer steel cylinder 108 is aligned with the outer edges of the two corners of one flange of the steel profile 112, and the other pair of opening components 106a on the outer wall of the inner steel cylinder 107 is aligned with the outer edges of the two corners of the other flange of the steel profile 112. The openings of the opening components 106a form grooves for the insertion and installation of the steel profile 112. To ensure reliable insertion and installation, the opening size a ≥ t, and the wrapping angle α > 90°. The opening shape includes, but is not limited to, U-shape or hook shape. The locking buckle 106 can position and lock the steel profile 112, ensuring its vertical downward insertion and installation. The vertical deviation of the steel profile 112 is no greater than 1 / 500.

[0050] Step S4, Construction of Improved Soil Between Well Walls: The soil 101 between the well walls is reinforced using the MJS reinforcement process to form improved soil 113, completing the construction of the double-layer steel caisson structure. After backfilling, the soil 101 between the well walls throughout the entire height of the caisson is improved using the MJS method. The initial pressure of the MJS reinforcement jet is 40 MPa, the flow rate is approximately 90–130 l / min, a single nozzle is used, the jetting time is 30–40 min per meter, and the average lifting speed is 2.5–3.3 cm / min. The improved soil 113 further enhances the structural strength of the annular gap between the layers of the double-layer steel cylinder.

[0051] Please refer to Figures 1 to 6 This invention also provides a double-layer steel caisson structure pressurization construction system, including a double-layer non-enclosed steel caisson wall subsystem, an anti-uplift pile system, a reaction force pressurization subsystem, and a soil reinforcement subsystem, wherein:

[0052] The double-layer non-enclosed steel well wall subsystem includes a double-layer steel cylinder with a locking buckle 106 as the double-layer well wall and multiple steel profiles 112 evenly arranged in the annular gap between the inner and outer steel cylinders. Each steel profile 112 is inserted into one of the locking buckles 106.

[0053] The tension pile system consists of multiple piles, evenly distributed circumferentially within the soil in the annular gap between the layers of a double-layer steel cylinder. The tension piles 102 and the steel section 112 are staggered.

[0054] The reaction force sinking subsystem is used to press the double-layer steel cylinder into the soil for caisson construction. It includes an anchor plate 103 anchored in the anti-uplift pile 102 and a steel strand 104 connected thereto. The steel strand 104 extends upward out of the double-layer steel cylinder and passes through the sinking crossbeam 109, the through jack 110 and the anchor 111, which are sequentially set at the top of the double-layer steel cylinder.

[0055] The soil reinforcement subsystem uses the MJS reinforcement process to reinforce the soil in the interlayer annular gap, forming improved soil 113 between the well walls.

[0056] The double-layer steel caisson structure and its pressing construction method and system provided in this invention have the advantages of rapid soil breaking, small soil squeezing effect, high pressing efficiency, and minimal disturbance to the surrounding environment. It avoids the problems of large soil squeezing effect and difficulty in sinking and large disturbance to the surrounding environment caused by using thick-walled concrete structure cylinders or double-layer closed steel cylinders as thick caisson walls. On the other hand, by inserting the installation steel 112 into the soil within the interlayer annular gap through the locking 106 of the double-layer steel cylinder, and by improving the soil between the well walls 101 through the MJS reinforcement process to form the improved soil between the well walls 113, a composite strength double-layer steel caisson structure is formed, consisting of the double-layer steel cylinder and the anti-uplift piles 102 in the interlayer annular gap, the steel 112, and the improved soil between the well walls 113. This improves the structural stiffness of the well wall and the bearing capacity of the water and soil pressure load on the side of the well wall, avoiding the problem of insufficient load bearing capacity on the side of the well wall caused by using a single-layer large-diameter steel cylinder as a thin well wall, resulting in excessive structural deformation and affecting construction safety.

[0057] The double-layer steel caisson structure and its press-in construction method and system provided in this invention can synchronously press the double-layer steel cylinder into the soil through a reaction pressure sinking subsystem, realizing press-in caisson construction instead of relying on the gravity sinking of the double-layer steel cylinder, thus improving the construction efficiency and stability of the double-layer steel cylinder caisson. The reaction pressure sinking subsystem consists of an anchor plate 103 anchored in the anti-tension pile 102 and its connected steel strand 104, as well as a sinking crossbeam 109, a through-hole jack 110, and an anchor 111 sequentially arranged upwards at the top of the double-layer steel cylinder through the steel strand 104. It has the advantages of simple structure, good stability, and low cost.

[0058] Please refer to Figure 2 The double-layer steel caisson structure and its press-in construction method and system provided in this embodiment of the invention have an anchor plate 103 anchored within the tension pile 102, which improves the stability of the reaction force pressing subsystem. To improve the reliability of the anchor plate 103 anchored within the tension pile 102, the anchorage length of the steel strand 104 within the tension pile 102 is not less than 50d and not less than 1000mm, where d is the diameter of the steel strand 104.

[0059] The double-layer steel caisson structure and its press-in construction method and system provided in this invention solve the problem of insufficient bearing capacity of water and soil pressure on the caisson wall side during the construction of large-diameter and ultra-deep caisson structures with diameters exceeding 15m and depths exceeding 20m, which leads to large structural deformation. It has the advantages of reliable and efficient caisson construction.

[0060] Please refer to Figure 6 The method for constructing a double-layer steel caisson structure by pressing in, as provided in this embodiment of the invention, may further include:

[0061] Step S5, caisson bottom sealing construction: After the improved soil 113 between the caisson walls reaches the design strength, the soil 114 inside the inner caisson wall is excavated, and concrete is poured for bottom sealing construction. This bottom sealing construction prevents groundwater leakage.

[0062] Please refer to Figure 6 To ultimately form a usable double-layer steel caisson structure, the press-fit construction method for the double-layer steel caisson structure provided in this embodiment of the invention may further include, before or after step S5:

[0063] Remove anchor 111, through jack 110 and sinking beam 109, and cut steel strand 104 above ground 105.

[0064] Please refer to Figures 1 to 2 To improve the stability of the reaction-force sinking subsystem, the present invention provides a method for the driven construction of a double-layer steel caisson structure. This method includes, but is not limited to, four tension piles 102, arranged symmetrically along two axes, with the pile positions positioned at angles of 30°, 150°, 210°, and 330° relative to the X-axis. Using four tension piles 102 enhances the stability of the reaction-force sinking subsystem under pressure. By balancing the forces at four points, the inner and outer layers of the steel cylinder are simultaneously driven down, improving the stability and efficiency of driving the double-layer steel cylinder into the soil.

[0065] This invention is not limited to the specific embodiments described above. Obviously, the embodiments described above are only a part of the embodiments of this invention, not all of them. All other embodiments obtained by those skilled in the art based on the described embodiments of this invention are within the scope of protection of this invention. Those skilled in the art can make other modifications and variations to this invention. Therefore, if these modifications and variations of this invention fall within the scope of the claims of this invention, then this invention also intends to include these modifications and variations.

Claims

1. A method for the forced-in construction of a double-layer steel caisson structure, characterized in that, include: Multiple circumferentially evenly arranged anti-tension piles are constructed in the soil between the walls of the double-layer steel caisson structure within the annular gap between the layers at the construction location, forming an anti-tension pile subsystem. Anchor plates and their connected steel strands are anchored inside each tension pile. The steel strands are extended upwards beyond the ground at the construction location. Double-layered steel cylinders with locking mechanisms are arranged in sections as double-layered well walls at the construction location, aligning the annular gaps between the layers of the double-layered steel cylinders with each tension pile. The steel strands are passed through the annular gaps between the layers and out of the double-layered steel cylinders. At the top of the double-layered steel cylinders, a sinking beam, a through-hole jack, and an anchor are sequentially installed upwards, so that the anchor plates, steel strands, sinking beam, through-hole jack, and anchor form a reaction sinking subsystem to provide downward pressure to the double-layered steel cylinders. The through-hole jack is controlled to repeatedly extend and retract, driving the steel strands to apply downward reaction force to the double-layered steel cylinders through the sinking beam and locking them with the anchor. This allows the double-layered steel cylinders with locking mechanisms, with tension piles embedded within them, to be synchronously and progressively sinked to the design depth within the soil. Insert the steel profile into the soil between the layers of the well wall along each locking position of the double-layer steel cylinder, so that the double-layer steel cylinder with locking and the steel profile form a double-layer non-enclosed steel well wall subsystem. The soil between the well walls in the interlayer annular gap is reinforced using the MJS reinforcement process to form improved soil between the well walls, thus completing the construction of the double-layer steel caisson structure.

2. The method for press-fitting construction of a double-layer steel caisson structure according to claim 1, characterized in that, Also includes: After the improved soil between the well walls reaches the design strength, the soil inside the pit in the inner well wall is excavated, and concrete is poured to seal the bottom.

3. The method for press-fitting construction of a double-layer steel caisson structure according to claim 1, characterized in that, Also includes: Remove the anchorages, through-hole jacks, and sinking beams, and cut the steel strands above ground.

4. The method for press-fitting construction of a double-layer steel caisson structure according to claim 1, characterized in that, The anti-tension piles consist of four piles, arranged in a biaxially symmetrical manner, with the pile positions positioned at angles of 30°, 150°, 210°, and 330° relative to the X-axis.

5. The method for press-fitting construction of a double-layer steel caisson structure according to claim 4, characterized in that, The steel profile consists of six sections arranged in a ring array within the annular gap between the layers of the double-layered steel cylinder.

6. The method for press-fit construction of a double-layer steel caisson structure according to claim 1, characterized in that, The steel section is an I-beam or an H-beam, with the plane of the web of the steel section aligned with the center of the circle, and the plane of the flange of the steel section parallel to the circumferential tangent of the double-layer steel cylinder.

7. The method for press-fit construction of a double-layer steel caisson structure according to claim 1, characterized in that, The anchorage length of the steel strand within the tension pile shall be no less than 50d and no less than 1000mm, where d is the diameter of the steel strand.

8. The method for press-fit construction of a double-layer steel caisson structure according to claim 1, characterized in that, The latch consists of four rectangularly distributed opening components, which are arranged in pairs on the inner wall of the outer steel cylinder and the outer wall of the inner steel cylinder. The pair of opening components arranged on the inner wall of the outer steel cylinder are aligned with the outer edges of the two corners of one flange of the steel section, and the pair of opening components arranged on the outer wall of the inner steel cylinder are aligned with the outer edges of the two corners of the other flange of the steel section.

9. A press-in construction system for a double-layer steel caisson structure, characterized in that, include: A double-layer non-enclosed steel well wall subsystem includes a double-layer steel cylinder with locking buckles and multiple steel profiles evenly arranged circumferentially within the annular gap between the inner and outer steel cylinders, with each steel profile correspondingly inserted into one of the locking buckles; The tension pile system consists of multiple piles, evenly distributed circumferentially within the soil in the annular gap between the layers of a double-layer steel cylinder, with the tension piles and the steel sections being staggered. The reaction pressure sinking subsystem is used to press the double-layer steel cylinder into the soil for caisson construction. It includes an anchor plate anchored in the anti-uplift pile and its connected steel strand. The steel strand extends upward out of the double-layer steel cylinder and passes through the steel strand. The sinking crossbeam, the through jack and the anchor are set at the top of the double-layer steel cylinder in sequence. The soil reinforcement subsystem uses the MJS reinforcement process to reinforce the soil within the interlayer annular gaps, forming improved soil between the well walls.

10. A double-layer steel caisson structure, characterized in that, include: The double-layer non-enclosed steel well wall includes a double-layer steel cylinder with locking buckles that extends into the soil and multiple steel sections evenly arranged in the annular gap between the layers, with each steel section being inserted into one of the locking buckles. The tension piles are multiple piles, evenly distributed circumferentially, installed in the soil within the annular gap between the layers of a double-layered steel cylinder. The tension piles are staggered from the steel sections. The improved soil between well walls is formed by reinforcing the soil in the annular gap between layers using the MJS reinforcement process.

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